From: Khalil Blaiech <kblaiech@xxxxxxxxxxxx> Add BlueField I2C driver to offer master and slave support for Mellanox BlueField SoCs. The driver implements an SMBus adapter and interfaces to multiple busses that can be probed using both ACPI and Device Tree infrastructures. The driver supports several SMBus operations to transfer data back and forth from/to various I2C devices. It is mainly intended to be consumed by userspace tools and utilities, such as i2c-tools and decode-dimms to collect memory module information. On the other hand, the driver has a slave function to support, among others, an IPMB interface that requires both master and slave functions to handle transfers between the BlueField SoC and a board management controllers (e.g., BMC). Signed-off-by: Khalil Blaiech <kblaiech@xxxxxxxxxxxx> Reviewed-by: Vadim Pasternak <vadimp@xxxxxxxxxxxx> --- v9->v10: - Fixing compile issue when building with gcc 9.3.0 and Werror enabled; remove unused variable in mlxbf_slave_enable(). v8->v9: - Replacing devm_ioremap_nocache and ioremap_nocache with devm_ioremap since the non-cached interface has been removed. v7->v8: - Removing 'COMPILE_TEST' dependency in Kconfig. - Fixing switch statement fallthrough comment to prevent warnings and/or build errors. v6->v7: - Fixing kernel coding style issues. - Rewording of the commit message. - Renaming of the driver filename. - Renaming of the macro, struture, variable and function names to be consistent with the module name. - Removing 'MELLANOX_PLATFORM' dependency in Kconfig. - Fixing bug in mlxbf_i2c_get_shared_resource() to prevent null pointer dereference. - Fixing bug in mlxbf_i2c_release_gpio() to prevent the use of null pointers. - Adding an entry to MAINTAINERS file. v5->v6: - Fixing kernel coding style issues detected using '--strict' flag. - Updating SPDX identifier and module license. v4->v5: - Fixing bug in mlx_slave_enale routine. v2->v3: - Updating the "compatible" string and add a new entry to the mlx_i2c_dt_ids array. - Adding a new entry to the mlx_i2c_acpi_ids array to support a new device _HID. - Updating the device probe routines to derive the device type based on the instance property described in either devicetree or ACPI. - Definition of new handlers to request and release the shared resources. These handlers relies on the device type. v1->v2: - Updating the '.compatible' field of of_device_id. - Updating mlx_i2c_of_probe() call to extract the bus identifier from the pre-defined aliases. - Removing the 'profile' property. - Setting the timing parameters according to the value of 'clock-frequency' property. - Convertng the timing configuration from KHz to Hz. --- MAINTAINERS | 6 + drivers/i2c/busses/Kconfig | 13 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-mlxbf.c | 2506 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 2526 insertions(+) create mode 100644 drivers/i2c/busses/i2c-mlxbf.c diff --git a/MAINTAINERS b/MAINTAINERS index 0d0862b..694df11 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11096,6 +11096,12 @@ W: http://www.melfas.com F: Documentation/devicetree/bindings/input/touchscreen/melfas_mip4.txt F: drivers/input/touchscreen/melfas_mip4.c +MELLANOX BLUEFIELD I2C DRIVER +M: Khalil Blaiech <kblaiech@xxxxxxxxxxxx> +L: linux-i2c@xxxxxxxxxxxxxxx +S: Supported +F: drivers/i2c/busses/i2c-mlxbf.c + MELLANOX ETHERNET DRIVER (mlx4_en) M: Tariq Toukan <tariqt@xxxxxxxxxx> L: netdev@xxxxxxxxxxxxxxx diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 293e7a0..4af7ccc 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -730,6 +730,19 @@ config I2C_LPC2K This driver can also be built as a module. If so, the module will be called i2c-lpc2k. +config I2C_MLXBF + tristate "Mellanox BlueField I2C controller" + depends on ARM64 + help + Enabling this option will add I2C SMBus support for Mellanox BlueField + system. + + This driver can also be built as a module. If so, the module will be + called i2c-mlxbf. + + This driver implements an I2C SMBus host controller and enables both + master and slave functions. + config I2C_MESON tristate "Amlogic Meson I2C controller" depends on ARCH_MESON || COMPILE_TEST diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 19aff0e..683c49f 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -140,6 +140,7 @@ obj-$(CONFIG_I2C_BRCMSTB) += i2c-brcmstb.o obj-$(CONFIG_I2C_CROS_EC_TUNNEL) += i2c-cros-ec-tunnel.o obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o obj-$(CONFIG_I2C_ICY) += i2c-icy.o +obj-$(CONFIG_I2C_MLXBF) += i2c-mlxbf.o obj-$(CONFIG_I2C_MLXCPLD) += i2c-mlxcpld.o obj-$(CONFIG_I2C_OPAL) += i2c-opal.o obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c new file mode 100644 index 0000000..a147401 --- /dev/null +++ b/drivers/i2c/busses/i2c-mlxbf.c @@ -0,0 +1,2506 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Mellanox BlueField I2C bus driver + * + * Copyright (C) 2020 Mellanox Technologies, Ltd. + */ + +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/i2c.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/string.h> + +/* Defines what functionality is present. */ +#define MLXBF_I2C_FUNC_SMBUS_BLOCK \ + (I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL) + +#define MLXBF_I2C_FUNC_SMBUS_DEFAULT \ + (I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | \ + I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | \ + I2C_FUNC_SMBUS_PROC_CALL) + +#define MLXBF_I2C_FUNC_ALL \ + (MLXBF_I2C_FUNC_SMBUS_DEFAULT | MLXBF_I2C_FUNC_SMBUS_BLOCK | \ + I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SLAVE) + +#define MLXBF_I2C_SMBUS_MAX 3 + +/* Shared resources info in BlueField platforms. */ + +#define MLXBF_I2C_COALESCE_TYU_ADDR 0x02801300 +#define MLXBF_I2C_COALESCE_TYU_SIZE 0x010 + +#define MLXBF_I2C_GPIO_TYU_ADDR 0x02802000 +#define MLXBF_I2C_GPIO_TYU_SIZE 0x100 + +#define MLXBF_I2C_COREPLL_TYU_ADDR 0x02800358 +#define MLXBF_I2C_COREPLL_TYU_SIZE 0x008 + +#define MLXBF_I2C_COREPLL_YU_ADDR 0x02800c30 +#define MLXBF_I2C_COREPLL_YU_SIZE 0x00c + +#define MLXBF_I2C_SHARED_RES_MAX 3 + +/* + * Note that the following SMBus, CAUSE, GPIO and PLL register addresses + * refer to their respective offsets relative to the corresponding + * memory-mapped region whose addresses are specified in either the DT or + * the ACPI tables or above. + */ + +/* + * SMBus Master core clock frequency. Timing configurations are + * strongly dependent on the core clock frequency of the SMBus + * Master. Default value is set to 400MHz. + */ +#define MLXBF_I2C_TYU_PLL_OUT_FREQ (400 * 1000 * 1000) +/* Reference clock for Bluefield 1 - 156 MHz. */ +#define MLXBF_I2C_TYU_PLL_IN_FREQ (156 * 1000 * 1000) +/* Reference clock for BlueField 2 - 200 MHz. */ +#define MLXBF_I2C_YU_PLL_IN_FREQ (200 * 1000 * 1000) + +/* Constant used to determine the PLL frequency. */ +#define MLNXBF_I2C_COREPLL_CONST 16384 + +/* PLL registers. */ +#define MLXBF_I2C_CORE_PLL_REG0 0x0 +#define MLXBF_I2C_CORE_PLL_REG1 0x4 +#define MLXBF_I2C_CORE_PLL_REG2 0x8 + +/* OR cause register. */ +#define MLXBF_I2C_CAUSE_OR_EVTEN0 0x14 +#define MLXBF_I2C_CAUSE_OR_CLEAR 0x18 + +/* Arbiter Cause Register. */ +#define MLXBF_I2C_CAUSE_ARBITER 0x1c + +/* + * Cause Status flags. Note that those bits might be considered + * as interrupt enabled bits. + */ + +/* Transaction ended with STOP. */ +#define MLXBF_I2C_CAUSE_TRANSACTION_ENDED BIT(0) +/* Master arbitration lost. */ +#define MLXBF_I2C_CAUSE_M_ARBITRATION_LOST BIT(1) +/* Unexpected start detected. */ +#define MLXBF_I2C_CAUSE_UNEXPECTED_START BIT(2) +/* Unexpected stop detected. */ +#define MLXBF_I2C_CAUSE_UNEXPECTED_STOP BIT(3) +/* Wait for transfer continuation. */ +#define MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA BIT(4) +/* Failed to generate STOP. */ +#define MLXBF_I2C_CAUSE_PUT_STOP_FAILED BIT(5) +/* Failed to generate START. */ +#define MLXBF_I2C_CAUSE_PUT_START_FAILED BIT(6) +/* Clock toggle completed. */ +#define MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE BIT(7) +/* Transfer timeout occurred. */ +#define MLXBF_I2C_CAUSE_M_FW_TIMEOUT BIT(8) +/* Master busy bit reset. */ +#define MLXBF_I2C_CAUSE_M_GW_BUSY_FALL BIT(9) + +#define MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK GENMASK(9, 0) + +#define MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR \ + (MLXBF_I2C_CAUSE_M_ARBITRATION_LOST | \ + MLXBF_I2C_CAUSE_UNEXPECTED_START | \ + MLXBF_I2C_CAUSE_UNEXPECTED_STOP | \ + MLXBF_I2C_CAUSE_PUT_STOP_FAILED | \ + MLXBF_I2C_CAUSE_PUT_START_FAILED | \ + MLXBF_I2C_CAUSE_CLK_TOGGLE_DONE | \ + MLXBF_I2C_CAUSE_M_FW_TIMEOUT) + +/* + * Slave cause status flags. Note that those bits might be considered + * as interrupt enabled bits. + */ + +/* Write transaction received successfully. */ +#define MLXBF_I2C_CAUSE_WRITE_SUCCESS BIT(0) +/* Read transaction received, waiting for response. */ +#define MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE BIT(13) +/* Slave busy bit reset. */ +#define MLXBF_I2C_CAUSE_S_GW_BUSY_FALL BIT(18) + +#define MLXBF_I2C_CAUSE_SLAVE_ARBITER_BITS_MASK GENMASK(20, 0) + +/* Cause coalesce registers. */ +#define MLXBF_I2C_CAUSE_COALESCE_0 0x00 +#define MLXBF_I2C_CAUSE_COALESCE_1 0x04 +#define MLXBF_I2C_CAUSE_COALESCE_2 0x08 + +#define MLXBF_I2C_CAUSE_TYU_SLAVE_BIT MLXBF_I2C_SMBUS_MAX +#define MLXBF_I2C_CAUSE_YU_SLAVE_BIT 1 + +/* Functional enable register. */ +#define MLXBF_I2C_GPIO_0_FUNC_EN_0 0x28 +/* Force OE enable register. */ +#define MLXBF_I2C_GPIO_0_FORCE_OE_EN 0x30 +/* + * Note that Smbus GWs are on GPIOs 30:25. Two pins are used to control + * SDA/SCL lines: + * + * SMBUS GW0 -> bits[26:25] + * SMBUS GW1 -> bits[28:27] + * SMBUS GW2 -> bits[30:29] + */ +#define MLXBF_I2C_GPIO_SMBUS_GW_PINS(num) (25 + ((num) << 1)) + +/* Note that gw_id can be 0,1 or 2. */ +#define MLXBF_I2C_GPIO_SMBUS_GW_MASK(num) \ + (0xffffffff & (~(0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num)))) + +#define MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(num, val) \ + ((val) & MLXBF_I2C_GPIO_SMBUS_GW_MASK(num)) + +#define MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(num, val) \ + ((val) | (0x3 << MLXBF_I2C_GPIO_SMBUS_GW_PINS(num))) + +/* SMBus timing parameters. */ +#define MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH 0x00 +#define MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE 0x04 +#define MLXBF_I2C_SMBUS_TIMER_THOLD 0x08 +#define MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP 0x0c +#define MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA 0x10 +#define MLXBF_I2C_SMBUS_THIGH_MAX_TBUF 0x14 +#define MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT 0x18 + +enum { + MLXBF_I2C_TIMING_100KHZ = 100000, + MLXBF_I2C_TIMING_400KHZ = 400000, + MLXBF_I2C_TIMING_1000KHZ = 1000000, +}; + +/* + * Defines SMBus operating frequency and core clock frequency. + * According to ADB files, default values are compliant to 100KHz SMBus + * @ 400MHz core clock. The driver should be able to calculate core + * frequency based on PLL parameters. + */ +#define MLXBF_I2C_COREPLL_FREQ MLXBF_I2C_TYU_PLL_OUT_FREQ + +/* Core PLL TYU configuration. */ +#define MLXBF_I2C_COREPLL_CORE_F_TYU_MASK GENMASK(12, 0) +#define MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK GENMASK(3, 0) +#define MLXBF_I2C_COREPLL_CORE_R_TYU_MASK GENMASK(5, 0) + +#define MLXBF_I2C_COREPLL_CORE_F_TYU_SHIFT 3 +#define MLXBF_I2C_COREPLL_CORE_OD_TYU_SHIFT 16 +#define MLXBF_I2C_COREPLL_CORE_R_TYU_SHIFT 20 + +/* Core PLL YU configuration. */ +#define MLXBF_I2C_COREPLL_CORE_F_YU_MASK GENMASK(25, 0) +#define MLXBF_I2C_COREPLL_CORE_OD_YU_MASK GENMASK(3, 0) +#define MLXBF_I2C_COREPLL_CORE_R_YU_MASK GENMASK(5, 0) + +#define MLXBF_I2C_COREPLL_CORE_F_YU_SHIFT 0 +#define MLXBF_I2C_COREPLL_CORE_OD_YU_SHIFT 1 +#define MLXBF_I2C_COREPLL_CORE_R_YU_SHIFT 26 + +/* Core PLL frequency. */ +static u64 mlxbf_i2c_corepll_frequency; + +/* SMBus Master GW. */ +#define MLXBF_I2C_SMBUS_MASTER_GW 0x200 +/* Number of bytes received and sent. */ +#define MLXBF_I2C_SMBUS_RS_BYTES 0x300 +/* Packet error check (PEC) value. */ +#define MLXBF_I2C_SMBUS_MASTER_PEC 0x304 +/* Status bits (ACK/NACK/FW Timeout). */ +#define MLXBF_I2C_SMBUS_MASTER_STATUS 0x308 +/* SMbus Master Finite State Machine. */ +#define MLXBF_I2C_SMBUS_MASTER_FSM 0x310 + +/* + * When enabled, the master will issue a stop condition in case of + * timeout while waiting for FW response. + */ +#define MLXBF_I2C_SMBUS_EN_FW_TIMEOUT 0x31c + +/* SMBus master GW control bits offset in MLXBF_I2C_SMBUS_MASTER_GW[31:3]. */ +#define MLXBF_I2C_MASTER_LOCK_BIT BIT(31) /* Lock bit. */ +#define MLXBF_I2C_MASTER_BUSY_BIT BIT(30) /* Busy bit. */ +#define MLXBF_I2C_MASTER_START_BIT BIT(29) /* Control start. */ +#define MLXBF_I2C_MASTER_CTL_WRITE_BIT BIT(28) /* Control write phase. */ +#define MLXBF_I2C_MASTER_CTL_READ_BIT BIT(19) /* Control read phase. */ +#define MLXBF_I2C_MASTER_STOP_BIT BIT(3) /* Control stop. */ + +#define MLXBF_I2C_MASTER_ENABLE \ + (MLXBF_I2C_MASTER_LOCK_BIT | MLXBF_I2C_MASTER_BUSY_BIT | \ + MLXBF_I2C_MASTER_START_BIT | MLXBF_I2C_MASTER_STOP_BIT) + +#define MLXBF_I2C_MASTER_ENABLE_WRITE \ + (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_WRITE_BIT) + +#define MLXBF_I2C_MASTER_ENABLE_READ \ + (MLXBF_I2C_MASTER_ENABLE | MLXBF_I2C_MASTER_CTL_READ_BIT) + +#define MLXBF_I2C_MASTER_SLV_ADDR_SHIFT 12 /* Slave address shift. */ +#define MLXBF_I2C_MASTER_WRITE_SHIFT 21 /* Control write bytes shift. */ +#define MLXBF_I2C_MASTER_SEND_PEC_SHIFT 20 /* Send PEC byte shift. */ +#define MLXBF_I2C_MASTER_PARSE_EXP_SHIFT 11 /* Parse expected bytes shift. */ +#define MLXBF_I2C_MASTER_READ_SHIFT 4 /* Control read bytes shift. */ + +/* SMBus master GW Data descriptor. */ +#define MLXBF_I2C_MASTER_DATA_DESC_ADDR 0x280 +#define MLXBF_I2C_MASTER_DATA_DESC_SIZE 0x80 /* Size in bytes. */ + +/* Maximum bytes to read/write per SMBus transaction. */ +#define MLXBF_I2C_MASTER_DATA_R_LENGTH MLXBF_I2C_MASTER_DATA_DESC_SIZE +#define MLXBF_I2C_MASTER_DATA_W_LENGTH (MLXBF_I2C_MASTER_DATA_DESC_SIZE - 1) + +/* All bytes were transmitted. */ +#define MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE BIT(0) +/* NACK received. */ +#define MLXBF_I2C_SMBUS_STATUS_NACK_RCV BIT(1) +/* Slave's byte count >128 bytes. */ +#define MLXBF_I2C_SMBUS_STATUS_READ_ERR BIT(2) +/* Timeout occurred. */ +#define MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT BIT(3) + +#define MLXBF_I2C_SMBUS_MASTER_STATUS_MASK GENMASK(3, 0) + +#define MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR \ + (MLXBF_I2C_SMBUS_STATUS_NACK_RCV | \ + MLXBF_I2C_SMBUS_STATUS_READ_ERR | \ + MLXBF_I2C_SMBUS_STATUS_FW_TIMEOUT) + +#define MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK BIT(31) +#define MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK BIT(15) + +/* SMBus slave GW. */ +#define MLXBF_I2C_SMBUS_SLAVE_GW 0x400 +/* Number of bytes received and sent from/to master. */ +#define MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES 0x500 +/* Packet error check (PEC) value. */ +#define MLXBF_I2C_SMBUS_SLAVE_PEC 0x504 +/* SMBus slave Finite State Machine (FSM). */ +#define MLXBF_I2C_SMBUS_SLAVE_FSM 0x510 +/* + * Should be set when all raised causes handled, and cleared by HW on + * every new cause. + */ +#define MLXBF_I2C_SMBUS_SLAVE_READY 0x52c + +/* SMBus slave GW control bits offset in MLXBF_I2C_SMBUS_SLAVE_GW[31:19]. */ +#define MLXBF_I2C_SLAVE_BUSY_BIT BIT(30) /* Busy bit. */ +#define MLXBF_I2C_SLAVE_WRITE_BIT BIT(29) /* Control write enable. */ + +#define MLXBF_I2C_SLAVE_ENABLE \ + (MLXBF_I2C_SLAVE_BUSY_BIT | MLXBF_I2C_SLAVE_WRITE_BIT) + +#define MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT 22 /* Number of bytes to write. */ +#define MLXBF_I2C_SLAVE_SEND_PEC_SHIFT 21 /* Send PEC byte shift. */ + +/* SMBus slave GW Data descriptor. */ +#define MLXBF_I2C_SLAVE_DATA_DESC_ADDR 0x480 +#define MLXBF_I2C_SLAVE_DATA_DESC_SIZE 0x80 /* Size in bytes. */ + +/* SMbus slave configuration registers. */ +#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG 0x514 +#define MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT 16 +#define MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT 7 +#define MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK GENMASK(6, 0) + +#define MLXBF_I2C_SLAVE_ADDR_ENABLED(addr) \ + ((addr) & (1 << MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT)) + +/* + * Timeout is given in microsends. Note also that timeout handling is not + * exact. + */ +#define MLXBF_I2C_SMBUS_TIMEOUT (300 * 1000) /* 300ms */ + +/* Encapsulates timing parameters. */ +struct mlxbf_i2c_timings { + u16 scl_high; /* Clock high period. */ + u16 scl_low; /* Clock low period. */ + u8 sda_rise; /* Data rise time. */ + u8 sda_fall; /* Data fall time. */ + u8 scl_rise; /* Clock rise time. */ + u8 scl_fall; /* Clock fall time. */ + u16 hold_start; /* Hold time after (REPEATED) START. */ + u16 hold_data; /* Data hold time. */ + u16 setup_start; /* REPEATED START condition setup time. */ + u16 setup_stop; /* STOP condition setup time. */ + u16 setup_data; /* Data setup time. */ + u16 pad; /* Padding. */ + u16 buf; /* Bus free time between STOP and START. */ + u16 thigh_max; /* Thigh max. */ + u32 timeout; /* Detect clock low timeout. */ +}; + +enum { + MLXBF_I2C_F_READ = BIT(0), + MLXBF_I2C_F_WRITE = BIT(1), + MLXBF_I2C_F_NORESTART = BIT(3), + MLXBF_I2C_F_SMBUS_OPERATION = BIT(4), + MLXBF_I2C_F_SMBUS_BLOCK = BIT(5), + MLXBF_I2C_F_SMBUS_PEC = BIT(6), + MLXBF_I2C_F_SMBUS_PROCESS_CALL = BIT(7), +}; + +struct mlxbf_i2c_smbus_operation { + u32 flags; + u32 length; /* Buffer length in bytes. */ + u8 *buffer; +}; + +#define MLXBF_I2C_SMBUS_OP_CNT_1 1 +#define MLXBF_I2C_SMBUS_OP_CNT_2 2 +#define MLXBF_I2C_SMBUS_OP_CNT_3 3 +#define MLXBF_I2C_SMBUS_MAX_OP_CNT MLXBF_I2C_SMBUS_OP_CNT_3 + +struct mlxbf_i2c_smbus_request { + u8 slave; + u8 operation_cnt; + struct mlxbf_i2c_smbus_operation operation[MLXBF_I2C_SMBUS_MAX_OP_CNT]; +}; + +struct mlxbf_i2c_resource { + void __iomem *io; + struct resource *params; + struct mutex *lock; + u8 type; +}; + +/* List of chip resources that are being accessed by the driver. */ +enum { + MLXBF_I2C_SMBUS_RES, + MLXBF_I2C_MST_CAUSE_RES, + MLXBF_I2C_SLV_CAUSE_RES, + MLXBF_I2C_COALESCE_RES, + MLXBF_I2C_COREPLL_RES, + MLXBF_I2C_GPIO_RES, + MLXBF_I2C_END_RES, +}; + +/* Helper macro to define an I2C resource parameters. */ +#define MLXBF_I2C_RES_PARAMS(addr, size, str) \ + { \ + .start = (addr), \ + .end = (addr) + (size) - 1, \ + .name = (str) \ + } + +static struct resource mlxbf_i2c_coalesce_tyu_params = + MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COALESCE_TYU_ADDR, + MLXBF_I2C_COALESCE_TYU_SIZE, + "COALESCE_MEM"); +static struct resource mlxbf_i2c_corepll_tyu_params = + MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_TYU_ADDR, + MLXBF_I2C_COREPLL_TYU_SIZE, + "COREPLL_MEM"); +static struct resource mlxbf_i2c_corepll_yu_params = + MLXBF_I2C_RES_PARAMS(MLXBF_I2C_COREPLL_YU_ADDR, + MLXBF_I2C_COREPLL_YU_SIZE, + "COREPLL_MEM"); +static struct resource mlxbf_i2c_gpio_tyu_params = + MLXBF_I2C_RES_PARAMS(MLXBF_I2C_GPIO_TYU_ADDR, + MLXBF_I2C_GPIO_TYU_SIZE, + "GPIO_MEM"); + +static struct mutex mlxbf_i2c_coalesce_lock; +static struct mutex mlxbf_i2c_corepll_lock; +static struct mutex mlxbf_i2c_gpio_lock; + +/* Mellanox BlueField chip type. */ +enum mlxbf_i2c_chip_type { + MLXBF_I2C_CHIP_TYPE_1, /* Mellanox BlueField-1 chip. */ + MLXBF_I2C_CHIP_TYPE_2, /* Mallanox BlueField-2 chip. */ +}; + +struct mlxbf_i2c_chip_info { + enum mlxbf_i2c_chip_type type; + /* Chip shared resources that are being used by the I2C controller. */ + struct mlxbf_i2c_resource *shared_res[MLXBF_I2C_SHARED_RES_MAX]; + + /* Callback to calculate the core PLL frequency. */ + u64 (*calculate_freq)(struct mlxbf_i2c_resource *corepll_res); +}; + +struct mlxbf_i2c_priv { + const struct mlxbf_i2c_chip_info *chip; + struct i2c_adapter adap; + struct mlxbf_i2c_resource *smbus; + struct mlxbf_i2c_resource *mst_cause; + struct mlxbf_i2c_resource *slv_cause; + struct mlxbf_i2c_resource *coalesce; + u64 frequency; /* Core frequency in Hz. */ + int bus; /* Physical bus identifier. */ + int irq; + struct i2c_client *slave; +}; + +static struct mlxbf_i2c_resource mlxbf_i2c_coalesce_res[] = { + [MLXBF_I2C_CHIP_TYPE_1] = { + .params = &mlxbf_i2c_coalesce_tyu_params, + .lock = &mlxbf_i2c_coalesce_lock, + .type = MLXBF_I2C_COALESCE_RES + }, + {} +}; + +static struct mlxbf_i2c_resource mlxbf_i2c_corepll_res[] = { + [MLXBF_I2C_CHIP_TYPE_1] = { + .params = &mlxbf_i2c_corepll_tyu_params, + .lock = &mlxbf_i2c_corepll_lock, + .type = MLXBF_I2C_COREPLL_RES + }, + [MLXBF_I2C_CHIP_TYPE_2] = { + .params = &mlxbf_i2c_corepll_yu_params, + .lock = &mlxbf_i2c_corepll_lock, + .type = MLXBF_I2C_COREPLL_RES, + } +}; + +static struct mlxbf_i2c_resource mlxbf_i2c_gpio_res[] = { + [MLXBF_I2C_CHIP_TYPE_1] = { + .params = &mlxbf_i2c_gpio_tyu_params, + .lock = &mlxbf_i2c_gpio_lock, + .type = MLXBF_I2C_GPIO_RES + }, + {} +}; + +static u8 mlxbf_i2c_bus_count; + +static struct mutex mlxbf_i2c_bus_lock; + +/* Polling frequency in microseconds. */ +#define MLXBF_I2C_POLL_FREQ_IN_USEC 200 + +#define MLXBF_I2C_SHIFT_0 0 +#define MLXBF_I2C_SHIFT_8 8 +#define MLXBF_I2C_SHIFT_16 16 +#define MLXBF_I2C_SHIFT_24 24 + +#define MLXBF_I2C_MASK_8 GENMASK(7, 0) +#define MLXBF_I2C_MASK_16 GENMASK(15, 0) + +#define MLXBF_I2C_FREQUENCY_1GHZ 1000000000 + +static void mlxbf_i2c_write(void __iomem *io, int reg, u32 val) +{ + writel(val, io + reg); +} + +static u32 mlxbf_i2c_read(void __iomem *io, int reg) +{ + return readl(io + reg); +} + +/* + * This function is used to read data from Master GW Data Descriptor. + * Data bytes in the Master GW Data Descriptor are shifted left so the + * data starts at the MSB of the descriptor registers as set by the + * underlying hardware. TYU_READ_DATA enables byte swapping while + * reading data bytes, and MUST be called by the SMBus read routines + * to copy data from the 32 * 32-bit HW Data registers a.k.a Master GW + * Data Descriptor. + */ +static u32 mlxbf_i2c_read_data(void __iomem *io, int reg) +{ + return be32_to_cpu(mlxbf_i2c_read(io, reg)); +} + +/* + * This function is used to write data to the Master GW Data Descriptor. + * Data copied to the Master GW Data Descriptor MUST be shifted left so + * the data starts at the MSB of the descriptor registers as required by + * the underlying hardware. TYU_WRITE_DATA enables byte swapping when + * writing data bytes, and MUST be called by the SMBus write routines to + * copy data to the 32 * 32-bit HW Data registers a.k.a Master GW Data + * Descriptor. + */ +static void mlxbf_i2c_write_data(void __iomem *io, int reg, u32 val) +{ + mlxbf_i2c_write(io, reg, cpu_to_be32(val)); +} + +/* + * Function to poll a set of bits at a specific address; it checks whether + * the bits are equal to zero when eq_zero is set to 'true', and not equal + * to zero when eq_zero is set to 'false'. + * Note that the timeout is given in microseconds. + */ +static u32 mlxbf_smbus_poll(void __iomem *io, u32 addr, u32 mask, + bool eq_zero, u32 timeout) +{ + u32 bits; + + timeout = (timeout / MLXBF_I2C_POLL_FREQ_IN_USEC) + 1; + + do { + bits = mlxbf_i2c_read(io, addr) & mask; + if (eq_zero ? bits == 0 : bits != 0) + return eq_zero ? 1 : bits; + udelay(MLXBF_I2C_POLL_FREQ_IN_USEC); + } while (timeout-- != 0); + + return 0; +} + +/* + * SW must make sure that the SMBus Master GW is idle before starting + * a transaction. Accordingly, this function polls the Master FSM stop + * bit; it returns false when the bit is asserted, true if not. + */ +static bool mlxbf_smbus_master_wait_for_idle(struct mlxbf_i2c_priv *priv) +{ + u32 mask = MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK; + u32 addr = MLXBF_I2C_SMBUS_MASTER_FSM; + u32 timeout = MLXBF_I2C_SMBUS_TIMEOUT; + + if (mlxbf_smbus_poll(priv->smbus->io, addr, mask, true, timeout)) + return true; + + return false; +} + +static bool mlxbf_i2c_smbus_transaction_success(u32 master_status, + u32 cause_status) +{ + /* + * When transaction ended with STOP, all bytes were transmitted, + * and no NACK received, then the transaction ended successfully. + * On the other hand, when the GW is configured with the stop bit + * de-asserted then the SMBus expects the following GW configuration + * for transfer continuation. + */ + if ((cause_status & MLXBF_I2C_CAUSE_WAIT_FOR_FW_DATA) || + ((cause_status & MLXBF_I2C_CAUSE_TRANSACTION_ENDED) && + (master_status & MLXBF_I2C_SMBUS_STATUS_BYTE_CNT_DONE) && + !(master_status & MLXBF_I2C_SMBUS_STATUS_NACK_RCV))) + return true; + + return false; +} + +/* + * Poll SMBus master status and return transaction status, + * i.e. whether succeeded or failed. I2C and SMBus fault codes + * are returned as negative numbers from most calls, with zero + * or some positive number indicating a non-fault return. + */ +static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv) +{ + u32 master_status_bits; + u32 cause_status_bits; + + /* + * GW busy bit is raised by the driver and cleared by the HW + * when the transaction is completed. The busy bit is a good + * indicator of transaction status. So poll the busy bit, and + * then read the cause and master status bits to determine if + * errors occurred during the transaction. + */ + mlxbf_smbus_poll(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_GW, + MLXBF_I2C_MASTER_BUSY_BIT, true, + MLXBF_I2C_SMBUS_TIMEOUT); + + /* Read cause status bits. */ + cause_status_bits = mlxbf_i2c_read(priv->mst_cause->io, + MLXBF_I2C_CAUSE_ARBITER); + cause_status_bits &= MLXBF_I2C_CAUSE_MASTER_ARBITER_BITS_MASK; + + /* + * Parse both Cause and Master GW bits, then return transaction status. + */ + + master_status_bits = mlxbf_i2c_read(priv->smbus->io, + MLXBF_I2C_SMBUS_MASTER_STATUS); + master_status_bits &= MLXBF_I2C_SMBUS_MASTER_STATUS_MASK; + + if (mlxbf_i2c_smbus_transaction_success(master_status_bits, + cause_status_bits)) + return 0; + + /* + * In case of timeout on GW busy, the ISR will clear busy bit but + * transaction ended bits cause will not be set so the transaction + * fails. Then, we must check Master GW status bits. + */ + if ((master_status_bits & MLXBF_I2C_SMBUS_MASTER_STATUS_ERROR) && + (cause_status_bits & (MLXBF_I2C_CAUSE_TRANSACTION_ENDED | + MLXBF_I2C_CAUSE_M_GW_BUSY_FALL))) + return -EIO; + + if (cause_status_bits & MLXBF_I2C_CAUSE_MASTER_STATUS_ERROR) + return -EAGAIN; + + return -ETIMEDOUT; +} + +static void mlxbf_i2c_smbus_write_data(struct mlxbf_i2c_priv *priv, + const u8 *data, u8 length, u32 addr) +{ + u8 offset, aligned_length; + u32 data32; + + aligned_length = round_up(length, 4); + + /* Copy data bytes from 4-byte aligned source buffer. */ + for (offset = 0; offset < aligned_length; offset += sizeof(u32)) { + data32 = *((u32 *)(data + offset)); + mlxbf_i2c_write_data(priv->smbus->io, addr + offset, data32); + } +} + +static void mlxbf_i2c_smbus_read_data(struct mlxbf_i2c_priv *priv, + u8 *data, u8 length, u32 addr) +{ + u32 data32, mask; + u8 byte, offset; + + mask = sizeof(u32) - 1; + + for (offset = 0; offset < (length & ~mask); offset += sizeof(u32)) { + data32 = mlxbf_i2c_read_data(priv->smbus->io, addr + offset); + *((u32 *)(data + offset)) = data32; + } + + if (!(length & mask)) + return; + + data32 = mlxbf_i2c_read_data(priv->smbus->io, addr + offset); + + for (byte = 0; byte < (length & mask); byte++) { + data[offset + byte] = data32 & GENMASK(7, 0); + data32 = ror32(data32, MLXBF_I2C_SHIFT_8); + } +} + +static int mlxbf_i2c_smbus_enable(struct mlxbf_i2c_priv *priv, u8 slave, + u8 len, u8 block_en, u8 pec_en, bool read) +{ + u32 command; + + /* Set Master GW control word. */ + if (read) { + command = MLXBF_I2C_MASTER_ENABLE_READ; + command |= rol32(len, MLXBF_I2C_MASTER_READ_SHIFT); + } else { + command = MLXBF_I2C_MASTER_ENABLE_WRITE; + command |= rol32(len, MLXBF_I2C_MASTER_WRITE_SHIFT); + } + command |= rol32(slave, MLXBF_I2C_MASTER_SLV_ADDR_SHIFT); + command |= rol32(block_en, MLXBF_I2C_MASTER_PARSE_EXP_SHIFT); + command |= rol32(pec_en, MLXBF_I2C_MASTER_SEND_PEC_SHIFT); + + /* Clear status bits. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_STATUS, 0x0); + /* Set the cause data. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_CAUSE_OR_CLEAR, ~0x0); + /* Zero PEC byte. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_PEC, 0x0); + /* Zero byte count. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_RS_BYTES, 0x0); + + /* GW activation. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_GW, command); + + /* + * Poll master status and check status bits. An ACK is sent when + * completing writing data to the bus (Master 'byte_count_done' bit + * is set to 1). + */ + return mlxbf_i2c_smbus_check_status(priv); +} + +static int +mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv, + struct mlxbf_i2c_smbus_request *request) +{ + u8 data_desc[MLXBF_I2C_MASTER_DATA_DESC_SIZE] = { 0 }; + u8 op_idx, data_idx, data_len, write_len, read_len; + struct mlxbf_i2c_smbus_operation *operation; + u8 read_en, write_en, block_en, pec_en; + u8 slave, flags, addr; + u8 *read_buf; + int ret = 0; + + if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT) + return -EINVAL; + + read_buf = NULL; + data_idx = 0; + read_en = 0; + write_en = 0; + write_len = 0; + read_len = 0; + block_en = 0; + pec_en = 0; + slave = request->slave & GENMASK(6, 0); + addr = slave << 1; + + /* First of all, check whether the HW is idle. */ + if (WARN_ON(!mlxbf_smbus_master_wait_for_idle(priv))) + return -EBUSY; + + /* Set first byte. */ + data_desc[data_idx++] = addr; + + for (op_idx = 0; op_idx < request->operation_cnt; op_idx++) { + operation = &request->operation[op_idx]; + flags = operation->flags; + + /* + * Note that read and write operations might be handled by a + * single command. If the MLXBF_I2C_F_SMBUS_OPERATION is set + * then write command byte and set the optional SMBus specific + * bits such as block_en and pec_en. These bits MUST be + * submitted by the first operation only. + */ + if (op_idx == 0 && flags & MLXBF_I2C_F_SMBUS_OPERATION) { + block_en = flags & MLXBF_I2C_F_SMBUS_BLOCK; + pec_en = flags & MLXBF_I2C_F_SMBUS_PEC; + } + + if (flags & MLXBF_I2C_F_WRITE) { + write_en = 1; + write_len += operation->length; + memcpy(data_desc + data_idx, + operation->buffer, operation->length); + data_idx += operation->length; + } + /* + * We assume that read operations are performed only once per + * SMBus transaction. *TBD* protect this statement so it won't + * be executed twice? or return an error if we try to read more + * than once? + */ + if (flags & MLXBF_I2C_F_READ) { + read_en = 1; + /* Subtract 1 as required by HW. */ + read_len = operation->length - 1; + read_buf = operation->buffer; + } + } + + /* Set Master GW data descriptor. */ + data_len = write_len + 1; /* Add one byte of the slave address. */ + /* + * Note that data_len cannot be 0. Indeed, the slave address byte + * must be written to the data registers. + */ + mlxbf_i2c_smbus_write_data(priv, (const u8 *)data_desc, data_len, + MLXBF_I2C_MASTER_DATA_DESC_ADDR); + + if (write_en) { + ret = mlxbf_i2c_smbus_enable(priv, slave, write_len, block_en, + pec_en, 0); + if (ret) + return ret; + } + + if (read_en) { + /* Write slave address to Master GW data descriptor. */ + mlxbf_i2c_smbus_write_data(priv, (const u8 *)&addr, 1, + MLXBF_I2C_MASTER_DATA_DESC_ADDR); + ret = mlxbf_i2c_smbus_enable(priv, slave, read_len, block_en, + pec_en, 1); + if (!ret) { + /* Get Master GW data descriptor. */ + mlxbf_i2c_smbus_read_data(priv, data_desc, read_len + 1, + MLXBF_I2C_MASTER_DATA_DESC_ADDR); + + /* Get data from Master GW data descriptor. */ + memcpy(read_buf, data_desc, read_len + 1); + } + + /* + * After a read operation the SMBus FSM ps (present state) + * needs to be 'manually' reset. This should be removed in + * next tag integration. + */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_MASTER_FSM, + MLXBF_I2C_SMBUS_MASTER_FSM_PS_STATE_MASK); + } + + return ret; +} + +/* I2C SMBus protocols. */ + +static void +mlxbf_i2c_smbus_quick_command(struct mlxbf_i2c_smbus_request *request, + u8 read) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1; + + request->operation[0].length = 0; + request->operation[0].flags = MLXBF_I2C_F_WRITE; + request->operation[0].flags |= read ? MLXBF_I2C_F_READ : 0; +} + +static void mlxbf_i2c_smbus_byte_func(struct mlxbf_i2c_smbus_request *request, + u8 *data, bool read, bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_1; + + request->operation[0].length = 1; + request->operation[0].length += pec_check; + + request->operation[0].flags = MLXBF_I2C_F_SMBUS_OPERATION; + request->operation[0].flags |= read ? + MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + + request->operation[0].buffer = data; +} + +static void +mlxbf_i2c_smbus_data_byte_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, bool read, bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + request->operation[1].length = 1; + request->operation[1].length += pec_check; + request->operation[1].flags = read ? + MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE; + request->operation[1].buffer = data; +} + +static void +mlxbf_i2c_smbus_data_word_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, bool read, bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + request->operation[1].length = 2; + request->operation[1].length += pec_check; + request->operation[1].flags = read ? + MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE; + request->operation[1].buffer = data; +} + +static void +mlxbf_i2c_smbus_i2c_block_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, u8 *data_len, bool read, + bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + /* + * As specified in the standard, the max number of bytes to read/write + * per block operation is 32 bytes. In Golan code, the controller can + * read up to 128 bytes and write up to 127 bytes. + */ + request->operation[1].length = + (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ? + I2C_SMBUS_BLOCK_MAX : *data_len + pec_check; + request->operation[1].flags = read ? + MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE; + /* + * Skip the first data byte, which corresponds to the number of bytes + * to read/write. + */ + request->operation[1].buffer = data + 1; + + *data_len = request->operation[1].length; + + /* Set the number of byte to read. This will be used by userspace. */ + if (read) + data[0] = *data_len; +} + +static void mlxbf_i2c_smbus_block_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, u8 *data_len, + bool read, bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_2; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + request->operation[1].length = + (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ? + I2C_SMBUS_BLOCK_MAX : *data_len + pec_check; + request->operation[1].flags = read ? + MLXBF_I2C_F_READ : MLXBF_I2C_F_WRITE; + request->operation[1].buffer = data + 1; + + *data_len = request->operation[1].length; + + /* Set the number of bytes to read. This will be used by userspace. */ + if (read) + data[0] = *data_len; +} + +static void +mlxbf_i2c_smbus_process_call_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, bool pec_check) +{ + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK; + request->operation[0].flags |= pec_check ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + request->operation[1].length = 2; + request->operation[1].flags = MLXBF_I2C_F_WRITE; + request->operation[1].buffer = data; + + request->operation[2].length = 3; + request->operation[2].flags = MLXBF_I2C_F_READ; + request->operation[2].buffer = data; +} + +static void +mlxbf_i2c_smbus_blk_process_call_func(struct mlxbf_i2c_smbus_request *request, + u8 *command, u8 *data, u8 *data_len, + bool pec_check) +{ + u32 length; + + request->operation_cnt = MLXBF_I2C_SMBUS_OP_CNT_3; + + request->operation[0].length = 1; + request->operation[0].flags = + MLXBF_I2C_F_SMBUS_OPERATION | MLXBF_I2C_F_WRITE; + request->operation[0].flags |= MLXBF_I2C_F_SMBUS_BLOCK; + request->operation[0].flags |= (pec_check) ? MLXBF_I2C_F_SMBUS_PEC : 0; + request->operation[0].buffer = command; + + length = (*data_len + pec_check > I2C_SMBUS_BLOCK_MAX) ? + I2C_SMBUS_BLOCK_MAX : *data_len + pec_check; + + request->operation[1].length = length - pec_check; + request->operation[1].flags = MLXBF_I2C_F_WRITE; + request->operation[1].buffer = data; + + request->operation[2].length = length; + request->operation[2].flags = MLXBF_I2C_F_READ; + request->operation[2].buffer = data; + + *data_len = length; /* including PEC byte. */ +} + +/* Initialization functions. */ + +static bool mlxbf_i2c_has_chip_type(struct mlxbf_i2c_priv *priv, u8 type) +{ + return priv->chip->type == type; +} + +static struct mlxbf_i2c_resource * +mlxbf_i2c_get_shared_resource(struct mlxbf_i2c_priv *priv, u8 type) +{ + const struct mlxbf_i2c_chip_info *chip = priv->chip; + struct mlxbf_i2c_resource *res; + u8 res_idx = 0; + + for (res_idx = 0; res_idx < MLXBF_I2C_SHARED_RES_MAX; res_idx++) { + res = chip->shared_res[res_idx]; + if (res && res->type == type) + return res; + } + + return NULL; +} + +static int mlxbf_i2c_init_resource(struct platform_device *pdev, + struct mlxbf_i2c_resource **res, + u8 type) +{ + struct mlxbf_i2c_resource *tmp_res; + struct device *dev = &pdev->dev; + + if (!res || *res || type >= MLXBF_I2C_END_RES) + return -EINVAL; + + tmp_res = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_resource), + GFP_KERNEL); + if (!tmp_res) + return -ENOMEM; + + tmp_res->params = platform_get_resource(pdev, IORESOURCE_MEM, type); + if (!tmp_res->params) { + devm_kfree(dev, tmp_res); + return -EIO; + } + + tmp_res->io = devm_ioremap_resource(dev, tmp_res->params); + if (IS_ERR(tmp_res->io)) { + devm_kfree(dev, tmp_res); + return PTR_ERR(tmp_res->io); + } + + tmp_res->type = type; + + *res = tmp_res; + + return 0; +} + +static u32 mlxbf_i2c_get_ticks(struct mlxbf_i2c_priv *priv, u64 nanoseconds, + bool minimum) +{ + u64 frequency; + u32 ticks; + + /* + * Compute ticks as follow: + * + * Ticks + * Time = --------- x 10^9 => Ticks = Time x Frequency x 10^-9 + * Frequency + */ + frequency = priv->frequency; + ticks = (nanoseconds * frequency) / MLXBF_I2C_FREQUENCY_1GHZ; + /* + * The number of ticks is rounded down and if minimum is equal to 1 + * then add one tick. + */ + if (minimum) + ticks++; + + return ticks; +} + +static u32 mlxbf_i2c_set_timer(struct mlxbf_i2c_priv *priv, u64 nsec, bool opt, + u32 mask, u8 shift) +{ + u32 val = (mlxbf_i2c_get_ticks(priv, nsec, opt) & mask) << shift; + + return val; +} + +static void mlxbf_i2c_set_timings(struct mlxbf_i2c_priv *priv, + const struct mlxbf_i2c_timings *timings) +{ + u32 timer; + + timer = mlxbf_i2c_set_timer(priv, timings->scl_high, + false, MLXBF_I2C_MASK_16, + MLXBF_I2C_SHIFT_0); + timer |= mlxbf_i2c_set_timer(priv, timings->scl_low, + false, MLXBF_I2C_MASK_16, + MLXBF_I2C_SHIFT_16); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_TIMER_SCL_LOW_SCL_HIGH, + timer); + + timer = mlxbf_i2c_set_timer(priv, timings->sda_rise, false, + MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_0); + timer |= mlxbf_i2c_set_timer(priv, timings->sda_fall, false, + MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_8); + timer |= mlxbf_i2c_set_timer(priv, timings->scl_rise, false, + MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_16); + timer |= mlxbf_i2c_set_timer(priv, timings->scl_fall, false, + MLXBF_I2C_MASK_8, MLXBF_I2C_SHIFT_24); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_TIMER_FALL_RISE_SPIKE, + timer); + + timer = mlxbf_i2c_set_timer(priv, timings->hold_start, true, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0); + timer |= mlxbf_i2c_set_timer(priv, timings->hold_data, true, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_TIMER_THOLD, timer); + + timer = mlxbf_i2c_set_timer(priv, timings->setup_start, true, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0); + timer |= mlxbf_i2c_set_timer(priv, timings->setup_stop, true, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16); + mlxbf_i2c_write(priv->smbus->io, + MLXBF_I2C_SMBUS_TIMER_TSETUP_START_STOP, timer); + + timer = mlxbf_i2c_set_timer(priv, timings->setup_data, true, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_TIMER_TSETUP_DATA, + timer); + + timer = mlxbf_i2c_set_timer(priv, timings->buf, false, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_0); + timer |= mlxbf_i2c_set_timer(priv, timings->thigh_max, false, + MLXBF_I2C_MASK_16, MLXBF_I2C_SHIFT_16); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_THIGH_MAX_TBUF, + timer); + + timer = timings->timeout; + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SCL_LOW_TIMEOUT, + timer); +} + +enum mlxbf_i2c_timings_config { + MLXBF_I2C_TIMING_CONFIG_100KHZ, + MLXBF_I2C_TIMING_CONFIG_400KHZ, + MLXBF_I2C_TIMING_CONFIG_1000KHZ, +}; + +/* + * Note that the mlxbf_i2c_timings->timeout value is not related to the + * bus frequency, it is impacted by the time it takes the driver to + * complete data transmission before transaction abort. + */ +static const struct mlxbf_i2c_timings mlxbf_i2c_timings[] = { + [MLXBF_I2C_TIMING_CONFIG_100KHZ] = { + .scl_high = 4810, + .scl_low = 5000, + .hold_start = 4000, + .setup_start = 4800, + .setup_stop = 4000, + .setup_data = 250, + .sda_rise = 50, + .sda_fall = 50, + .scl_rise = 50, + .scl_fall = 50, + .hold_data = 300, + .buf = 20000, + .thigh_max = 5000, + .timeout = 106500 + }, + [MLXBF_I2C_TIMING_CONFIG_400KHZ] = { + .scl_high = 1011, + .scl_low = 1300, + .hold_start = 600, + .setup_start = 700, + .setup_stop = 600, + .setup_data = 100, + .sda_rise = 50, + .sda_fall = 50, + .scl_rise = 50, + .scl_fall = 50, + .hold_data = 300, + .buf = 20000, + .thigh_max = 5000, + .timeout = 106500 + }, + [MLXBF_I2C_TIMING_CONFIG_1000KHZ] = { + .scl_high = 600, + .scl_low = 1300, + .hold_start = 600, + .setup_start = 600, + .setup_stop = 600, + .setup_data = 100, + .sda_rise = 50, + .sda_fall = 50, + .scl_rise = 50, + .scl_fall = 50, + .hold_data = 300, + .buf = 20000, + .thigh_max = 5000, + .timeout = 106500 + } +}; + +static int mlxbf_i2c_init_timings(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + enum mlxbf_i2c_timings_config config_idx; + struct device *dev = &pdev->dev; + u32 config_khz; + + int ret; + + ret = device_property_read_u32(dev, "clock-frequency", &config_khz); + if (ret < 0) + config_khz = MLXBF_I2C_TIMING_100KHZ; + + switch (config_khz) { + default: + /* Default settings is 100 KHz. */ + pr_warn("Illegal value %d: defaulting to 100 KHz\n", + config_khz); + /* Fall-through. */ + case MLXBF_I2C_TIMING_100KHZ: + config_idx = MLXBF_I2C_TIMING_CONFIG_100KHZ; + break; + + case MLXBF_I2C_TIMING_400KHZ: + config_idx = MLXBF_I2C_TIMING_CONFIG_400KHZ; + break; + + case MLXBF_I2C_TIMING_1000KHZ: + config_idx = MLXBF_I2C_TIMING_CONFIG_1000KHZ; + break; + } + + mlxbf_i2c_set_timings(priv, &mlxbf_i2c_timings[config_idx]); + + return 0; +} + +static int mlxbf_i2c_get_gpio(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *gpio_res; + struct device *dev = &pdev->dev; + struct resource *params; + resource_size_t size; + + gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES); + if (!gpio_res) + return -EPERM; + + /* + * The GPIO region in TYU space is shared among I2C busses. + * This function MUST be serialized to avoid racing when + * claiming the memory region and/or setting up the GPIO. + */ + lockdep_assert_held(gpio_res->lock); + + /* Check whether the memory map exist. */ + if (gpio_res->io) + return 0; + + params = gpio_res->params; + size = resource_size(params); + + if (!devm_request_mem_region(dev, params->start, size, params->name)) + return -EFAULT; + + gpio_res->io = devm_ioremap(dev, params->start, size); + if (IS_ERR(gpio_res->io)) { + devm_release_mem_region(dev, params->start, size); + return PTR_ERR(gpio_res->io); + } + + return 0; +} + +static int mlxbf_i2c_release_gpio(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *gpio_res; + struct device *dev = &pdev->dev; + struct resource *params; + + gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES); + if (!gpio_res) + return 0; + + mutex_lock(gpio_res->lock); + + if (gpio_res->io) { + /* Release the GPIO resource. */ + params = gpio_res->params; + devm_iounmap(dev, gpio_res->io); + devm_release_mem_region(dev, params->start, + resource_size(params)); + } + + mutex_unlock(gpio_res->lock); + + return 0; +} + +static int mlxbf_i2c_get_corepll(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *corepll_res; + struct device *dev = &pdev->dev; + struct resource *params; + resource_size_t size; + + corepll_res = mlxbf_i2c_get_shared_resource(priv, + MLXBF_I2C_COREPLL_RES); + if (!corepll_res) + return -EPERM; + + /* + * The COREPLL region in TYU space is shared among I2C busses. + * This function MUST be serialized to avoid racing when + * claiming the memory region. + */ + lockdep_assert_held(corepll_res->lock); + + /* Check whether the memory map exist. */ + if (corepll_res->io) + return 0; + + params = corepll_res->params; + size = resource_size(params); + + if (!devm_request_mem_region(dev, params->start, size, params->name)) + return -EFAULT; + + corepll_res->io = devm_ioremap(dev, params->start, size); + if (IS_ERR(corepll_res->io)) { + devm_release_mem_region(dev, params->start, size); + return PTR_ERR(corepll_res->io); + } + + return 0; +} + +static int mlxbf_i2c_release_corepll(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *corepll_res; + struct device *dev = &pdev->dev; + struct resource *params; + + corepll_res = mlxbf_i2c_get_shared_resource(priv, + MLXBF_I2C_COREPLL_RES); + + mutex_lock(corepll_res->lock); + + if (corepll_res->io) { + /* Release the CorePLL resource. */ + params = corepll_res->params; + devm_iounmap(dev, corepll_res->io); + devm_release_mem_region(dev, params->start, + resource_size(params)); + } + + mutex_unlock(corepll_res->lock); + + return 0; +} + +static int mlxbf_i2c_init_master(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *gpio_res; + struct device *dev = &pdev->dev; + u32 config_reg; + int ret; + + /* This configuration is only needed for BlueField 1. */ + if (!mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) + return 0; + + gpio_res = mlxbf_i2c_get_shared_resource(priv, MLXBF_I2C_GPIO_RES); + if (!gpio_res) + return -EPERM; + + /* + * The GPIO region in TYU space is shared among I2C busses. + * This function MUST be serialized to avoid racing when + * claiming the memory region and/or setting up the GPIO. + */ + + mutex_lock(gpio_res->lock); + + ret = mlxbf_i2c_get_gpio(pdev, priv); + if (ret < 0) { + dev_err(dev, "Failed to get gpio resource"); + mutex_unlock(gpio_res->lock); + return ret; + } + + /* + * TYU - Configuration for GPIO pins. Those pins must be asserted in + * MLXBF_I2C_GPIO_0_FUNC_EN_0, i.e. GPIO 0 is controlled by HW, and must + * be reset in MLXBF_I2C_GPIO_0_FORCE_OE_EN, i.e. GPIO_OE will be driven + * instead of HW_OE. + * For now, we do not reset the GPIO state when the driver is removed. + * First, it is not necessary to disable the bus since we are using + * the same busses. Then, some busses might be shared among Linux and + * platform firmware; disabling the bus might compromise the system + * functionality. + */ + config_reg = mlxbf_i2c_read(gpio_res->io, + MLXBF_I2C_GPIO_0_FUNC_EN_0); + config_reg = MLXBF_I2C_GPIO_SMBUS_GW_ASSERT_PINS(priv->bus, + config_reg); + mlxbf_i2c_write(gpio_res->io, MLXBF_I2C_GPIO_0_FUNC_EN_0, + config_reg); + + config_reg = mlxbf_i2c_read(gpio_res->io, + MLXBF_I2C_GPIO_0_FORCE_OE_EN); + config_reg = MLXBF_I2C_GPIO_SMBUS_GW_RESET_PINS(priv->bus, + config_reg); + mlxbf_i2c_write(gpio_res->io, MLXBF_I2C_GPIO_0_FORCE_OE_EN, + config_reg); + + mutex_unlock(gpio_res->lock); + + return 0; +} + +static u64 mlxbf_calculate_freq_from_tyu(struct mlxbf_i2c_resource *corepll_res) +{ + u64 core_frequency, pad_frequency; + u8 core_od, core_r; + u32 corepll_val; + u16 core_f; + + pad_frequency = MLXBF_I2C_TYU_PLL_IN_FREQ; + + corepll_val = mlxbf_i2c_read(corepll_res->io, + MLXBF_I2C_CORE_PLL_REG1); + + /* Get Core PLL configuration bits. */ + core_f = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_F_TYU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_F_TYU_MASK; + core_od = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_OD_TYU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_OD_TYU_MASK; + core_r = rol32(corepll_val, MLXBF_I2C_COREPLL_CORE_R_TYU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_R_TYU_MASK; + + /* + * Compute PLL output frequency as follow: + * + * CORE_F + 1 + * PLL_OUT_FREQ = PLL_IN_FREQ * ---------------------------- + * (CORE_R + 1) * (CORE_OD + 1) + * + * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency + * and PadFrequency, respectively. + */ + core_frequency = pad_frequency * (++core_f); + core_frequency /= (++core_r) * (++core_od); + + return core_frequency; +} + +static u64 mlxbf_calculate_freq_from_yu(struct mlxbf_i2c_resource *corepll_res) +{ + u32 corepll_reg1_val, corepll_reg2_val; + u64 corepll_frequency, pad_frequency; + u8 core_od, core_r; + u32 core_f; + + pad_frequency = MLXBF_I2C_YU_PLL_IN_FREQ; + + corepll_reg1_val = mlxbf_i2c_read(corepll_res->io, + MLXBF_I2C_CORE_PLL_REG1); + corepll_reg2_val = mlxbf_i2c_read(corepll_res->io, + MLXBF_I2C_CORE_PLL_REG2); + + /* Get Core PLL configuration bits */ + core_f = rol32(corepll_reg1_val, MLXBF_I2C_COREPLL_CORE_F_YU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_F_YU_MASK; + core_r = rol32(corepll_reg1_val, MLXBF_I2C_COREPLL_CORE_R_YU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_R_YU_MASK; + core_od = rol32(corepll_reg2_val, MLXBF_I2C_COREPLL_CORE_OD_YU_SHIFT) & + MLXBF_I2C_COREPLL_CORE_OD_YU_MASK; + + /* + * Compute PLL output frequency as follow: + * + * CORE_F / 16384 + * PLL_OUT_FREQ = PLL_IN_FREQ * ---------------------------- + * (CORE_R + 1) * (CORE_OD + 1) + * + * Where PLL_OUT_FREQ and PLL_IN_FREQ refer to CoreFrequency + * and PadFrequency, respectively. + */ + corepll_frequency = (pad_frequency * core_f) / MLNXBF_I2C_COREPLL_CONST; + corepll_frequency /= (++core_r) * (++core_od); + + return corepll_frequency; +} + +static int mlxbf_i2c_calculate_corepll_freq(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + const struct mlxbf_i2c_chip_info *chip = priv->chip; + struct mlxbf_i2c_resource *corepll_res; + struct device *dev = &pdev->dev; + u64 *freq = &priv->frequency; + int ret; + + corepll_res = mlxbf_i2c_get_shared_resource(priv, + MLXBF_I2C_COREPLL_RES); + if (!corepll_res) + return -EPERM; + + /* + * First, check whether the TYU core Clock frequency is set. + * The TYU core frequency is the same for all I2C busses; when + * the first device gets probed the frequency is determined and + * stored into a globally visible variable. So, first of all, + * check whether the frequency is already set. Here, we assume + * that the frequency is expected to be greater than 0. + */ + mutex_lock(corepll_res->lock); + if (!mlxbf_i2c_corepll_frequency) { + if (!chip->calculate_freq) { + mutex_unlock(corepll_res->lock); + return -EPERM; + } + + ret = mlxbf_i2c_get_corepll(pdev, priv); + if (ret < 0) { + dev_err(dev, "Failed to get corePLL resource"); + mutex_unlock(corepll_res->lock); + return ret; + } + + mlxbf_i2c_corepll_frequency = chip->calculate_freq(corepll_res); + } + mutex_unlock(corepll_res->lock); + + *freq = mlxbf_i2c_corepll_frequency; + + return 0; +} + +static int mlxbf_slave_enable(struct mlxbf_i2c_priv *priv, u8 addr) +{ + u32 slave_reg, slave_reg_tmp, slave_reg_avail, slave_addr_mask; + u8 reg, reg_cnt, byte, addr_tmp, reg_avail, byte_avail; + bool avail, disabled; + + disabled = false; + avail = false; + + if (!priv) + return -EPERM; + + reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2; + slave_addr_mask = MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK; + + /* + * Read the slave registers. There are 4 * 32-bit slave registers. + * Each slave register can hold up to 4 * 8-bit slave configuration + * (7-bit address, 1 status bit (1 if enabled, 0 if not)). + */ + for (reg = 0; reg < reg_cnt; reg++) { + slave_reg = mlxbf_i2c_read(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4); + /* + * Each register holds 4 slave addresses. So, we have to keep + * the byte order consistent with the value read in order to + * update the register correctly, if needed. + */ + slave_reg_tmp = slave_reg; + for (byte = 0; byte < 4; byte++) { + addr_tmp = slave_reg_tmp & GENMASK(7, 0); + + /* + * Mark the first available slave address slot, i.e. its + * enabled bit should be unset. This slot might be used + * later on to register our slave. + */ + if (!avail && !MLXBF_I2C_SLAVE_ADDR_ENABLED(addr_tmp)) { + avail = true; + reg_avail = reg; + byte_avail = byte; + slave_reg_avail = slave_reg; + } + + /* + * Parse slave address bytes and check whether the + * slave address already exists and it's enabled, + * i.e. most significant bit is set. + */ + if ((addr_tmp & slave_addr_mask) == addr) { + if (MLXBF_I2C_SLAVE_ADDR_ENABLED(addr_tmp)) + return 0; + disabled = true; + break; + } + + /* Parse next byte. */ + slave_reg_tmp >>= 8; + } + + /* Exit the loop if the slave address is found. */ + if (disabled) + break; + } + + if (!avail && !disabled) + return -EINVAL; /* No room for a new slave address. */ + + if (avail && !disabled) { + reg = reg_avail; + byte = byte_avail; + /* Set the slave address. */ + slave_reg_avail &= ~(slave_addr_mask << (byte * 8)); + slave_reg_avail |= addr << (byte * 8); + slave_reg = slave_reg_avail; + } + + /* Enable the slave address and update the register. */ + slave_reg |= (1 << MLXBF_I2C_SMBUS_SLAVE_ADDR_EN_BIT) << (byte * 8); + mlxbf_i2c_write(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4, slave_reg); + + return 0; +} + +static int mlxbf_slave_disable(struct mlxbf_i2c_priv *priv) +{ + u32 slave_reg, slave_reg_tmp, slave_addr_mask; + u8 addr, addr_tmp, reg, reg_cnt, slave_byte; + struct i2c_client *client = priv->slave; + bool exist; + + exist = false; + + addr = client->addr; + reg_cnt = MLXBF_I2C_SMBUS_SLAVE_ADDR_CNT >> 2; + slave_addr_mask = MLXBF_I2C_SMBUS_SLAVE_ADDR_MASK; + + /* + * Read the slave registers. There are 4 * 32-bit slave registers. + * Each slave register can hold up to 4 * 8-bit slave configuration + * (7-bit address, 1 status bit (1 if enabled, 0 if not)). + */ + for (reg = 0; reg < reg_cnt; reg++) { + slave_reg = mlxbf_i2c_read(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4); + + /* Check whether the address slots are empty. */ + if (slave_reg == 0) + continue; + + /* + * Each register holds 4 slave addresses. So, we have to keep + * the byte order consistent with the value read in order to + * update the register correctly, if needed. + */ + slave_reg_tmp = slave_reg; + slave_byte = 0; + while (slave_reg_tmp != 0) { + addr_tmp = slave_reg_tmp & slave_addr_mask; + /* + * Parse slave address bytes and check whether the + * slave address already exists. + */ + if (addr_tmp == addr) { + exist = true; + break; + } + + /* Parse next byte. */ + slave_reg_tmp >>= 8; + slave_byte += 1; + } + + /* Exit the loop if the slave address is found. */ + if (exist) + break; + } + + if (!exist) + return 0; /* Slave is not registered, nothing to do. */ + + /* Cleanup the slave address slot. */ + slave_reg &= ~(GENMASK(7, 0) << (slave_byte * 8)); + mlxbf_i2c_write(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_ADDR_CFG + reg * 0x4, slave_reg); + + return 0; +} + +static int mlxbf_i2c_init_coalesce(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *coalesce_res; + struct resource *params; + resource_size_t size; + int ret = 0; + + /* + * Unlike BlueField-1 platform, the coalesce registers is a dedicated + * resource in the next generations of BlueField. + */ + if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) { + coalesce_res = mlxbf_i2c_get_shared_resource(priv, + MLXBF_I2C_COALESCE_RES); + if (!coalesce_res) + return -EPERM; + + /* + * The Cause Coalesce group in TYU space is shared among + * I2C busses. This function MUST be serialized to avoid + * racing when claiming the memory region. + */ + lockdep_assert_held(mlxbf_i2c_gpio_res->lock); + + /* Check whether the memory map exist. */ + if (coalesce_res->io) { + priv->coalesce = coalesce_res; + return 0; + } + + params = coalesce_res->params; + size = resource_size(params); + + if (!request_mem_region(params->start, size, params->name)) + return -EFAULT; + + coalesce_res->io = ioremap(params->start, size); + if (IS_ERR(coalesce_res->io)) { + release_mem_region(params->start, size); + return PTR_ERR(coalesce_res->io); + } + + priv->coalesce = coalesce_res; + + } else { + ret = mlxbf_i2c_init_resource(pdev, &priv->coalesce, + MLXBF_I2C_COALESCE_RES); + } + + return ret; +} + +static int mlxbf_i2c_release_coalesce(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct mlxbf_i2c_resource *coalesce_res; + struct device *dev = &pdev->dev; + struct resource *params; + resource_size_t size; + + coalesce_res = priv->coalesce; + + if (coalesce_res->io) { + params = coalesce_res->params; + size = resource_size(params); + if (mlxbf_i2c_has_chip_type(priv, MLXBF_I2C_CHIP_TYPE_1)) { + mutex_lock(coalesce_res->lock); + iounmap(coalesce_res->io); + release_mem_region(params->start, size); + mutex_unlock(coalesce_res->lock); + } else { + devm_release_mem_region(dev, params->start, size); + } + } + + return 0; +} + +static int mlxbf_i2c_init_slave(struct platform_device *pdev, + struct mlxbf_i2c_priv *priv) +{ + struct device *dev = &pdev->dev; + u32 int_reg; + int ret; + + /* Reset FSM. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_FSM, 0); + + /* + * Enable slave cause interrupt bits. Drive + * MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE and + * MLXBF_I2C_CAUSE_WRITE_SUCCESS, these are enabled when an external + * masters issue a Read and Write, respectively. But, clear all + * interrupts first. + */ + mlxbf_i2c_write(priv->slv_cause->io, + MLXBF_I2C_CAUSE_OR_CLEAR, ~0); + int_reg = MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE; + int_reg |= MLXBF_I2C_CAUSE_WRITE_SUCCESS; + mlxbf_i2c_write(priv->slv_cause->io, + MLXBF_I2C_CAUSE_OR_EVTEN0, int_reg); + + /* Finally, set the 'ready' bit to start handling transactions. */ + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_READY, 0x1); + + /* Initialize the cause coalesce resource. */ + ret = mlxbf_i2c_init_coalesce(pdev, priv); + if (ret < 0) { + dev_err(dev, "failed to initialize cause coalesce\n"); + return ret; + } + + return 0; +} + +static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read, + bool *write) +{ + const struct mlxbf_i2c_chip_info *chip = priv->chip; + u32 coalesce0_reg, cause_reg; + u8 slave_shift, is_set; + + *write = false; + *read = false; + + slave_shift = chip->type != MLXBF_I2C_CHIP_TYPE_1 ? + MLXBF_I2C_CAUSE_YU_SLAVE_BIT : + priv->bus + MLXBF_I2C_CAUSE_TYU_SLAVE_BIT; + + coalesce0_reg = mlxbf_i2c_read(priv->coalesce->io, + MLXBF_I2C_CAUSE_COALESCE_0); + is_set = coalesce0_reg & (1 << slave_shift); + + if (!is_set) + return false; + + /* Check the source of the interrupt, i.e. whether a Read or Write. */ + cause_reg = mlxbf_i2c_read(priv->slv_cause->io, + MLXBF_I2C_CAUSE_ARBITER); + if (cause_reg & MLXBF_I2C_CAUSE_READ_WAIT_FW_RESPONSE) + *read = true; + else if (cause_reg & MLXBF_I2C_CAUSE_WRITE_SUCCESS) + *write = true; + + /* Clear cause bits. */ + mlxbf_i2c_write(priv->slv_cause->io, MLXBF_I2C_CAUSE_OR_CLEAR, ~0x0); + + return true; +} + +static bool mlxbf_smbus_slave_wait_for_idle(struct mlxbf_i2c_priv *priv, + u32 timeout) +{ + u32 mask = MLXBF_I2C_CAUSE_S_GW_BUSY_FALL; + u32 addr = MLXBF_I2C_CAUSE_ARBITER; + + if (mlxbf_smbus_poll(priv->slv_cause->io, addr, mask, false, timeout)) + return true; + + return false; +} + +/* Send byte to 'external' smbus master. */ +static int mlxbf_smbus_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes) +{ + u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 }; + u8 write_size, pec_en, addr, byte, value, byte_cnt, desc_size; + struct i2c_client *slave = priv->slave; + u32 control32, data32; + int ret; + + if (!slave) + return -EINVAL; + + addr = 0; + byte = 0; + desc_size = MLXBF_I2C_SLAVE_DATA_DESC_SIZE; + + /* + * Read bytes received from the external master. These bytes should + * be located in the first data descriptor register of the slave GW. + * These bytes are the slave address byte and the internal register + * address, if supplied. + */ + if (recv_bytes > 0) { + data32 = mlxbf_i2c_read_data(priv->smbus->io, + MLXBF_I2C_SLAVE_DATA_DESC_ADDR); + + /* Parse the received bytes. */ + switch (recv_bytes) { + case 2: + byte = (data32 >> 8) & GENMASK(7, 0); + /* Fall-through. */ + case 1: + addr = (data32 & GENMASK(7, 0)) >> 1; + } + + /* Check whether it's our slave address. */ + if (slave->addr != addr) + return -EINVAL; + } + + /* + * I2C read transactions may start by a WRITE followed by a READ. + * Indeed, most slave devices would expect the internal address + * following the slave address byte. So, write that byte first, + * and then, send the requested data bytes to the master. + */ + if (recv_bytes > 1) { + i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); + value = byte; + ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, + &value); + i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + + if (ret < 0) + return ret; + } + + /* + * Now, send data to the master; currently, the driver supports + * READ_BYTE, READ_WORD and BLOCK READ protocols. Note that the + * hardware can send up to 128 bytes per transfer. That is the + * size of its data registers. + */ + i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); + + for (byte_cnt = 0; byte_cnt < desc_size; byte_cnt++) { + data_desc[byte_cnt] = value; + i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value); + } + + /* Send a stop condition to the backend. */ + i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + + /* Handle the actual transfer. */ + + /* Set the number of bytes to write to master. */ + write_size = (byte_cnt - 1) & 0x7f; + + /* Write data to Slave GW data descriptor. */ + mlxbf_i2c_smbus_write_data(priv, data_desc, byte_cnt, + MLXBF_I2C_SLAVE_DATA_DESC_ADDR); + + pec_en = 0; /* Disable PEC since it is not supported. */ + + /* Prepare control word. */ + control32 = MLXBF_I2C_SLAVE_ENABLE; + control32 |= rol32(write_size, MLXBF_I2C_SLAVE_WRITE_BYTES_SHIFT); + control32 |= rol32(pec_en, MLXBF_I2C_SLAVE_SEND_PEC_SHIFT); + + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_GW, control32); + + /* + * Wait until the transfer is completed; the driver will wait + * until the GW is idle, a cause will rise on fall of GW busy. + */ + mlxbf_smbus_slave_wait_for_idle(priv, MLXBF_I2C_SMBUS_TIMEOUT); + + /* Release the Slave GW. */ + mlxbf_i2c_write(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES, 0x0); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_PEC, 0x0); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_READY, 0x1); + + return 0; +} + +/* Receive bytes from 'external' smbus master. */ +static int mlxbf_smbus_irq_recv(struct mlxbf_i2c_priv *priv, u8 recv_bytes) +{ + u8 data_desc[MLXBF_I2C_SLAVE_DATA_DESC_SIZE] = { 0 }; + struct i2c_client *slave = priv->slave; + u8 value, byte, addr; + int ret = 0; + + if (!slave) + return -EINVAL; + + /* Read data from Slave GW data descriptor. */ + mlxbf_i2c_smbus_read_data(priv, data_desc, recv_bytes, + MLXBF_I2C_SLAVE_DATA_DESC_ADDR); + + /* Check whether its our slave address. */ + addr = data_desc[0] >> 1; + if (slave->addr != addr) + return -EINVAL; + + /* + * Notify the slave backend; another I2C master wants to write data + * to us. This event is sent once the slave address and the write bit + * is detected. + */ + i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); + + /* Send the received data to the slave backend. */ + for (byte = 1; byte < recv_bytes; byte++) { + value = data_desc[byte]; + ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, + &value); + if (ret < 0) + break; + } + + /* Send a stop condition to the backend. */ + i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + + /* Release the Slave GW. */ + mlxbf_i2c_write(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES, 0x0); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_PEC, 0x0); + mlxbf_i2c_write(priv->smbus->io, MLXBF_I2C_SMBUS_SLAVE_READY, 0x1); + + return ret; +} + +static irqreturn_t mlxbf_smbus_irq(int irq, void *ptr) +{ + struct mlxbf_i2c_priv *priv = ptr; + bool read, write, irq_is_set; + u32 rw_bytes_reg; + u8 recv_bytes; + + /* + * Read TYU interrupt register and determine the source of the + * interrupt. Based on the source of the interrupt one of the + * following actions are performed: + * - Receive data and send response to master. + * - Send data and release slave GW. + * + * Handle read/write transaction only. CRmaster and Iarp requests + * are ignored for now. + */ + irq_is_set = mlxbf_i2c_has_coalesce(priv, &read, &write); + if (!irq_is_set || (!read && !write)) { + /* Nothing to do here, interrupt was not from this device. */ + return IRQ_NONE; + } + + /* + * The MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES includes the number of + * bytes from/to master. These are defined by 8-bits each. If the lower + * 8 bits are set, then the master expect to read N bytes from the + * slave, if the higher 8 bits are sent then the slave expect N bytes + * from the master. + */ + rw_bytes_reg = mlxbf_i2c_read(priv->smbus->io, + MLXBF_I2C_SMBUS_SLAVE_RS_MASTER_BYTES); + recv_bytes = (rw_bytes_reg >> 8) & GENMASK(7, 0); + + /* + * For now, the slave supports 128 bytes transfer. Discard remaining + * data bytes if the master wrote more than + * MLXBF_I2C_SLAVE_DATA_DESC_SIZE, i.e, the actual size of the slave + * data descriptor. + * + * Note that we will never expect to transfer more than 128 bytes; as + * specified in the SMBus standard, block transactions cannot exceed + * 32 bytes. + */ + recv_bytes = recv_bytes > MLXBF_I2C_SLAVE_DATA_DESC_SIZE ? + MLXBF_I2C_SLAVE_DATA_DESC_SIZE : recv_bytes; + + if (read) + mlxbf_smbus_irq_send(priv, recv_bytes); + else + mlxbf_smbus_irq_recv(priv, recv_bytes); + + return IRQ_HANDLED; +} + +/* Return negative errno on error. */ +static s32 mlxbf_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, + union i2c_smbus_data *data) +{ + struct mlxbf_i2c_smbus_request request = { 0 }; + struct mlxbf_i2c_priv *priv; + bool read, pec; + u8 byte_cnt; + + request.slave = addr; + + read = (read_write == I2C_SMBUS_READ); + pec = flags & I2C_FUNC_SMBUS_PEC; + + switch (size) { + case I2C_SMBUS_QUICK: + mlxbf_i2c_smbus_quick_command(&request, read); + dev_dbg(&adap->dev, "smbus quick, slave 0x%02x\n", addr); + break; + + case I2C_SMBUS_BYTE: + mlxbf_i2c_smbus_byte_func(&request, + read ? &data->byte : &command, read, + pec); + dev_dbg(&adap->dev, "smbus %s byte, slave 0x%02x.\n", + read ? "read" : "write", addr); + break; + + case I2C_SMBUS_BYTE_DATA: + mlxbf_i2c_smbus_data_byte_func(&request, &command, &data->byte, + read, pec); + dev_dbg(&adap->dev, "smbus %s byte data at 0x%02x, slave 0x%02x.\n", + read ? "read" : "write", command, addr); + break; + + case I2C_SMBUS_WORD_DATA: + mlxbf_i2c_smbus_data_word_func(&request, &command, + (u8 *)&data->word, read, pec); + dev_dbg(&adap->dev, "smbus %s word data at 0x%02x, slave 0x%02x.\n", + read ? "read" : "write", command, addr); + break; + + case I2C_SMBUS_I2C_BLOCK_DATA: + byte_cnt = data->block[0]; + mlxbf_i2c_smbus_i2c_block_func(&request, &command, data->block, + &byte_cnt, read, pec); + dev_dbg(&adap->dev, "i2c %s block data, %d bytes at 0x%02x, slave 0x%02x.\n", + read ? "read" : "write", byte_cnt, command, addr); + break; + + case I2C_SMBUS_BLOCK_DATA: + byte_cnt = read ? I2C_SMBUS_BLOCK_MAX : data->block[0]; + mlxbf_i2c_smbus_block_func(&request, &command, data->block, + &byte_cnt, read, pec); + dev_dbg(&adap->dev, "smbus %s block data, %d bytes at 0x%02x, slave 0x%02x.\n", + read ? "read" : "write", byte_cnt, command, addr); + break; + + case I2C_FUNC_SMBUS_PROC_CALL: + mlxbf_i2c_smbus_process_call_func(&request, &command, + (u8 *)&data->word, pec); + dev_dbg(&adap->dev, "process call, wr/rd at 0x%02x, slave 0x%02x.\n", + command, addr); + break; + + case I2C_FUNC_SMBUS_BLOCK_PROC_CALL: + byte_cnt = data->block[0]; + mlxbf_i2c_smbus_blk_process_call_func(&request, &command, + data->block, &byte_cnt, + pec); + dev_dbg(&adap->dev, "block process call, wr/rd %d bytes, slave 0x%02x.\n", + byte_cnt, addr); + break; + + default: + dev_dbg(&adap->dev, "Unsupported I2C/SMBus command %d\n", + size); + return -EOPNOTSUPP; + } + + priv = i2c_get_adapdata(adap); + + return mlxbf_i2c_smbus_start_transaction(priv, &request); +} + +static int mlxbf_i2c_reg_slave(struct i2c_client *slave) +{ + struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter); + int ret; + + if (priv->slave) + return -EBUSY; + + /* + * Do not support ten bit chip address and do not use Packet Error + * Checking (PEC). + */ + if (slave->flags & (I2C_CLIENT_TEN | I2C_CLIENT_PEC)) + return -EAFNOSUPPORT; + + ret = mlxbf_slave_enable(priv, slave->addr); + if (ret < 0) + return ret; + + priv->slave = slave; + + return 0; +} + +static int mlxbf_i2c_unreg_slave(struct i2c_client *slave) +{ + struct mlxbf_i2c_priv *priv = i2c_get_adapdata(slave->adapter); + int ret; + + WARN_ON(!priv->slave); + + /* Unregister slave, i.e. disable the slave address in hardware. */ + ret = mlxbf_slave_disable(priv); + if (ret < 0) + return ret; + + priv->slave = NULL; + + return 0; +} + +static u32 mlxbf_i2c_functionality(struct i2c_adapter *adap) +{ + return MLXBF_I2C_FUNC_ALL; +} + +static struct mlxbf_i2c_chip_info mlxbf_i2c_chip[] = { + [MLXBF_I2C_CHIP_TYPE_1] = { + .type = MLXBF_I2C_CHIP_TYPE_1, + .shared_res = { + [0] = &mlxbf_i2c_coalesce_res[MLXBF_I2C_CHIP_TYPE_1], + [1] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_1], + [2] = &mlxbf_i2c_gpio_res[MLXBF_I2C_CHIP_TYPE_1] + }, + .calculate_freq = mlxbf_calculate_freq_from_tyu + }, + [MLXBF_I2C_CHIP_TYPE_2] = { + .type = MLXBF_I2C_CHIP_TYPE_2, + .shared_res = { + [0] = &mlxbf_i2c_corepll_res[MLXBF_I2C_CHIP_TYPE_2] + }, + .calculate_freq = mlxbf_calculate_freq_from_yu + } +}; + +static const struct i2c_algorithm mlxbf_i2c_algo = { + .smbus_xfer = mlxbf_i2c_smbus_xfer, + .functionality = mlxbf_i2c_functionality, + .reg_slave = mlxbf_i2c_reg_slave, + .unreg_slave = mlxbf_i2c_unreg_slave, +}; + +static struct i2c_adapter_quirks mlxbf_i2c_quirks = { + .max_read_len = MLXBF_I2C_MASTER_DATA_R_LENGTH, + .max_write_len = MLXBF_I2C_MASTER_DATA_W_LENGTH, +}; + +static const struct of_device_id mlxbf_i2c_dt_ids[] = { + { + .compatible = "mellanox,i2c-mlxbf1", + .data = &mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] + }, + { + .compatible = "mellanox,i2c-mlxbf2", + .data = &mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] + }, + {}, +}; + +MODULE_DEVICE_TABLE(of, mlxbf_i2c_dt_ids); + +static const struct acpi_device_id mlxbf_i2c_acpi_ids[] = { + { "MLNXBF03", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_1] }, + { "MLNXBF23", (kernel_ulong_t)&mlxbf_i2c_chip[MLXBF_I2C_CHIP_TYPE_2] }, + {}, +}; + +MODULE_DEVICE_TABLE(acpi, mlxbf_i2c_acpi_ids); + +static int mlxbf_i2c_acpi_probe(struct device *dev, struct mlxbf_i2c_priv *priv) +{ + const struct acpi_device_id *aid; + struct acpi_device *adev; + unsigned long bus_id = 0; + const char *uid; + int ret; + + if (acpi_disabled) + return -ENOENT; + + adev = ACPI_COMPANION(dev); + if (!adev) + return -ENXIO; + + aid = acpi_match_device(mlxbf_i2c_acpi_ids, dev); + if (!aid) + return -ENODEV; + + priv->chip = (struct mlxbf_i2c_chip_info *)aid->driver_data; + + uid = acpi_device_uid(adev); + if (!uid || !(*uid)) { + dev_err(dev, "Cannot retrieve UID\n"); + return -ENODEV; + } + + ret = kstrtoul(uid, 0, &bus_id); + if (!ret) + priv->bus = bus_id; + + return ret; +} + +static int mlxbf_i2c_of_probe(struct device *dev, struct mlxbf_i2c_priv *priv) +{ + const struct of_device_id *oid; + int bus_id = -1; + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + oid = of_match_node(mlxbf_i2c_dt_ids, dev->of_node); + if (!oid) + return -ENODEV; + + priv->chip = oid->data; + + bus_id = of_alias_get_id(dev->of_node, "i2c"); + if (bus_id >= 0) + priv->bus = bus_id; + } + + if (bus_id < 0) { + dev_err(dev, "Cannot get bus id"); + return bus_id; + } + + return 0; +} + +static int mlxbf_i2c_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mlxbf_i2c_priv *priv; + struct i2c_adapter *adap; + int irq, ret; + + priv = devm_kzalloc(dev, sizeof(struct mlxbf_i2c_priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + ret = mlxbf_i2c_acpi_probe(dev, priv); + if (ret < 0 && ret != -ENOENT && ret != -ENXIO) + ret = mlxbf_i2c_of_probe(dev, priv); + + if (ret < 0) + return ret; + + ret = mlxbf_i2c_init_resource(pdev, &priv->smbus, + MLXBF_I2C_SMBUS_RES); + if (ret < 0) { + dev_err(dev, "Cannot fetch smbus resource info"); + return ret; + } + + ret = mlxbf_i2c_init_resource(pdev, &priv->mst_cause, + MLXBF_I2C_MST_CAUSE_RES); + if (ret < 0) { + dev_err(dev, "Cannot fetch cause master resource info"); + return ret; + } + + ret = mlxbf_i2c_init_resource(pdev, &priv->slv_cause, + MLXBF_I2C_SLV_CAUSE_RES); + if (ret < 0) { + dev_err(dev, "Cannot fetch cause slave resource info"); + return ret; + } + + adap = &priv->adap; + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_HWMON; + adap->algo = &mlxbf_i2c_algo; + adap->quirks = &mlxbf_i2c_quirks; + adap->dev.parent = dev; + adap->dev.of_node = dev->of_node; + adap->nr = priv->bus; + + snprintf(adap->name, sizeof(adap->name), "i2c%d", adap->nr); + i2c_set_adapdata(adap, priv); + + /* Read Core PLL frequency. */ + ret = mlxbf_i2c_calculate_corepll_freq(pdev, priv); + if (ret < 0) { + dev_err(dev, "cannot get core clock frequency\n"); + /* Set to default value. */ + priv->frequency = MLXBF_I2C_COREPLL_FREQ; + } + + /* + * Initialize master. + * Note that a physical bus might be shared among Linux and firmware + * (e.g., ATF). Thus, the bus should be initialized and ready and + * bus initialization would be unnecessary. This requires additional + * knowledge about physical busses. But, since an extra initialization + * does not really hurt, then keep the code as is. + */ + ret = mlxbf_i2c_init_master(pdev, priv); + if (ret < 0) { + dev_err(dev, "failed to initialize smbus master %d", + priv->bus); + return ret; + } + + mlxbf_i2c_init_timings(pdev, priv); + + mlxbf_i2c_init_slave(pdev, priv); + + irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(dev, irq, mlxbf_smbus_irq, + IRQF_ONESHOT | IRQF_SHARED | IRQF_PROBE_SHARED, + dev_name(dev), priv); + if (ret < 0) { + dev_err(dev, "Cannot get irq %d\n", irq); + return ret; + } + + priv->irq = irq; + + platform_set_drvdata(pdev, priv); + + ret = i2c_add_numbered_adapter(adap); + if (ret < 0) + return ret; + + mutex_lock(&mlxbf_i2c_bus_lock); + mlxbf_i2c_bus_count++; + mutex_unlock(&mlxbf_i2c_bus_lock); + + return 0; +} + +static int mlxbf_i2c_remove(struct platform_device *pdev) +{ + struct mlxbf_i2c_priv *priv = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + struct resource *params; + + params = priv->smbus->params; + devm_release_mem_region(dev, params->start, resource_size(params)); + + params = priv->mst_cause->params; + devm_release_mem_region(dev, params->start, resource_size(params)); + + params = priv->slv_cause->params; + devm_release_mem_region(dev, params->start, resource_size(params)); + + /* + * Release shared resources. This should be done when releasing + * the I2C controller. + */ + mutex_lock(&mlxbf_i2c_bus_lock); + if (--mlxbf_i2c_bus_count == 0) { + mlxbf_i2c_release_coalesce(pdev, priv); + mlxbf_i2c_release_corepll(pdev, priv); + mlxbf_i2c_release_gpio(pdev, priv); + } + mutex_unlock(&mlxbf_i2c_bus_lock); + + devm_free_irq(dev, priv->irq, priv); + + i2c_del_adapter(&priv->adap); + + return 0; +} + +static struct platform_driver mlxbf_i2c_driver = { + .probe = mlxbf_i2c_probe, + .remove = mlxbf_i2c_remove, + .driver = { + .name = "i2c-mlxbf", + .of_match_table = mlxbf_i2c_dt_ids, + .acpi_match_table = ACPI_PTR(mlxbf_i2c_acpi_ids), + }, +}; + +static int __init mlxbf_i2c_init(void) +{ + mutex_init(&mlxbf_i2c_coalesce_lock); + mutex_init(&mlxbf_i2c_corepll_lock); + mutex_init(&mlxbf_i2c_gpio_lock); + + mutex_init(&mlxbf_i2c_bus_lock); + + return platform_driver_register(&mlxbf_i2c_driver); +} +module_init(mlxbf_i2c_init); + +static void __exit mlxbf_i2c_exit(void) +{ + platform_driver_unregister(&mlxbf_i2c_driver); + + mutex_destroy(&mlxbf_i2c_bus_lock); + + mutex_destroy(&mlxbf_i2c_gpio_lock); + mutex_destroy(&mlxbf_i2c_corepll_lock); + mutex_destroy(&mlxbf_i2c_coalesce_lock); +} +module_exit(mlxbf_i2c_exit); + +MODULE_DESCRIPTION("Mellanox BlueField I2C bus driver"); +MODULE_AUTHOR("Khalil Blaiech <kblaiech@xxxxxxxxxxxx>"); +MODULE_LICENSE("GPL v2"); -- 2.1.2
