From: Daire McNamara <Daire.McNamara@xxxxxxxxxxxxx>
Add support for i2c on Microchip PolarFire SoC
Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 6 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-microchip.c | 519 +++++++++++++++++++++++++++++
3 files changed, 526 insertions(+)
create mode 100755 drivers/i2c/busses/i2c-microchip.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 3eec59f1fed3..2a7e3b27cb7f 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -747,6 +747,12 @@ config I2C_MESON
If you say yes to this option, support will be included for the
I2C interface on the Amlogic Meson family of SoCs.
+config I2C_MICROCHIP
+ tristate "Microchip I2C"
+ help
+ If you say yes to this option, support will be included for the
+ Microchip I2C interface.
+
config I2C_MPC
tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
depends on PPC
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 615f35e3e31f..0962ce7bfd20 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -73,6 +73,7 @@ obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o
obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o
obj-$(CONFIG_I2C_LPC2K) += i2c-lpc2k.o
obj-$(CONFIG_I2C_MESON) += i2c-meson.o
+obj-$(CONFIG_I2C_MICROCHIP) += i2c-microchip.o
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
obj-$(CONFIG_I2C_MT65XX) += i2c-mt65xx.o
obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o
diff --git a/drivers/i2c/busses/i2c-microchip.c b/drivers/i2c/busses/i2c-microchip.c
new file mode 100755
index 000000000000..0d75b248b41b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-microchip.c
@@ -0,0 +1,519 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip I2C controller driver
+ *
+ * Copyright (c) 2018 - 2021 Microchip Corporation. All rights reserved.
+ *
+ * Author: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
+ */
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/iopoll.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+#define MICROCHIP_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+#define MPFS_I2C_CTRL (0x00)
+#define CTRL_CR0 (0x00)
+#define CTRL_CR1 (0x01)
+#define CTRL_AA (0x02)
+#define CTRL_SI (0x03)
+#define CTRL_STO (0x04)
+#define CTRL_STA (0x05)
+#define CTRL_ENS1 (0x06)
+#define CTRL_CR2 (0x07)
+#define MPFS_I2C_STATUS (0x04)
+#define STATUS_BUS_ERROR (0x00)
+#define STATUS_M_START_SENT (0x08)
+#define STATUS_M_REPEATED_START_SENT (0x10)
+#define STATUS_M_SLAW_ACK (0x18)
+#define STATUS_M_SLAW_NACK (0x20)
+#define STATUS_M_TX_DATA_ACK (0x28)
+#define STATUS_M_TX_DATA_NACK (0x30)
+#define STATUS_M_ARB_LOST (0x38)
+#define STATUS_M_SLAR_ACK (0x40)
+#define STATUS_M_SLAR_NACK (0x48)
+#define STATUS_M_RX_DATA_ACKED (0x50)
+#define STATUS_M_RX_DATA_NACKED (0x58)
+#define STATUS_S_SLAW_ACKED (0x60)
+#define STATUS_S_ARB_LOST_SLAW_ACKED (0x68)
+#define STATUS_S_GENERAL_CALL_ACKED (0x70)
+#define STATUS_S_ARB_LOST_GENERAL_CALL_ACKED (0x78)
+#define STATUS_S_RX_DATA_ACKED (0x80)
+#define STATUS_S_RX_DATA_NACKED (0x88)
+#define STATUS_S_GENERAL_CALL_RX_DATA_ACKED (0x90)
+#define STATUS_S_GENERAL_CALL_RX_DATA_NACKED (0x98)
+#define STATUS_S_RX_STOP (0xA0)
+#define STATUS_S_SLAR_ACKED (0xA8)
+#define STATUS_S_ARB_LOST_SLAR_ACKED (0xB0)
+#define STATUS_S_TX_DATA_ACK (0xb8)
+#define STATUS_S_TX_DATA_NACK (0xC0)
+#define STATUS_LAST_DATA_ACK (0xC8)
+#define STATUS_M_SMB_MASTER_RESET (0xD0)
+#define STATUS_S_SCL_LOW_TIMEOUT (0xD8) /* 25 ms */
+#define STATUS_NO_STATE_INFO (0xF8)
+#define MPFS_I2C_DATA (0x08)
+#define WRITE_BIT (0)
+#define READ_BIT BIT(0)
+#define SLAVE_ADDR_SHIFT (1)
+#define MPFS_I2C_SLAVE0_ADDR (0x0c)
+#define GENERAL_CALL_BIT BIT(0)
+#define MPFS_I2C_SMBUS (0x10)
+#define SMBALERT_INT_ENB (0)
+#define SMBSUS_INT_ENB (1)
+#define SMBUS_ENB (2)
+#define SMBALERT_NI_STATUS (3)
+#define SMBALERT_NO_CTRL (4)
+#define SMBSUS_NI_STATUS (5)
+#define SMBSUS_NO_CTRL (6)
+#define SMBUS_RESET (7)
+#define MPFS_I2C_FREQ (0x14)
+#define MPFS_I2C_GLITCHREG (0x18)
+#define MPFS_I2C_SLAVE1_ADDR (0x1c)
+
+#define PCLK_DIV_256 ((0 << CTRL_CR0) | (0 << CTRL_CR1) | (0 << CTRL_CR2))
+#define PCLK_DIV_224 ((1 << CTRL_CR0) | (0 << CTRL_CR1) | (0 << CTRL_CR2))
+#define PCLK_DIV_192 ((0 << CTRL_CR0) | (1 << CTRL_CR1) | (0 << CTRL_CR2))
+#define PCLK_DIV_160 ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (0 << CTRL_CR2))
+#define PCLK_DIV_960 ((0 << CTRL_CR0) | (0 << CTRL_CR1) | (1 << CTRL_CR2))
+#define PCLK_DIV_120 ((1 << CTRL_CR0) | (0 << CTRL_CR1) | (1 << CTRL_CR2))
+#define PCLK_DIV_60 ((0 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2))
+#define BCLK_DIV_8 ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2))
+#define CLK_MASK ((1 << CTRL_CR0) | (1 << CTRL_CR1) | (1 << CTRL_CR2))
+
+/*
+ * mpfs_i2c_dev - I2C device context
+ * @base: pointer to register struct
+ * @msg: pointer to current message
+ * @msg_len: number of bytes transferred in msg
+ * @msg_err: error code for completed message
+ * @msg_complete: xfer completion object
+ * @dev: device reference
+ * @adapter: core i2c abstraction
+ * @i2c_clk: clock reference for i2c input clock
+ * @bus_clk_rate: current i2c bus clock rate
+ * @buf: ptr to msg buffer for easier use.
+ * @isr_status: cached copy of local ISR status.
+ * @lock: spinlock for IRQ synchronization.
+ */
+struct mpfs_i2c_dev {
+ void __iomem *base;
+ size_t msg_len;
+ int msg_err;
+ struct completion msg_complete;
+ struct device *dev;
+ struct i2c_adapter adapter;
+ struct clk *i2c_clk;
+ u32 bus_clk_rate;
+ u8 *buf;
+ u8 addr;
+ u32 msg_read;
+ u32 isr_status;
+ spinlock_t lock; /* IRQ synchronization */
+};
+
+static void mpfs_i2c_int_clear(struct mpfs_i2c_dev *idev)
+{
+ u8 ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl &= ~(1 << CTRL_SI);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+}
+
+static void mpfs_i2c_core_disable(struct mpfs_i2c_dev *idev)
+{
+ u8 ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl &= ~(1 << CTRL_ENS1);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+}
+
+static void mpfs_i2c_core_enable(struct mpfs_i2c_dev *idev)
+{
+ u8 ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl |= (1 << CTRL_ENS1);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+}
+
+static void mpfs_i2c_reset(struct mpfs_i2c_dev *idev)
+{
+ mpfs_i2c_core_disable(idev);
+ mpfs_i2c_core_enable(idev);
+}
+
+static inline void mpfs_i2c_stop(struct mpfs_i2c_dev *idev)
+{
+ u8 ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl |= (1 << CTRL_STO);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+}
+
+static inline int mpfs_generate_divisor(u32 rate, u8 *code)
+{
+ int ret = 0;
+
+ if (rate >= 960)
+ *code = PCLK_DIV_960;
+ else if (rate >= 256)
+ *code = PCLK_DIV_256;
+ else if (rate >= 224)
+ *code = PCLK_DIV_224;
+ else if (rate >= 192)
+ *code = PCLK_DIV_192;
+ else if (rate >= 160)
+ *code = PCLK_DIV_160;
+ else if (rate >= 120)
+ *code = PCLK_DIV_120;
+ else if (rate >= 60)
+ *code = PCLK_DIV_60;
+ else if (rate >= 8)
+ *code = BCLK_DIV_8;
+ else
+ ret = -1;
+
+ return ret;
+}
+
+static int mpfs_i2c_init(struct mpfs_i2c_dev *idev)
+{
+ u32 clk_rate = clk_get_rate(idev->i2c_clk);
+ u32 divisor = clk_rate / idev->bus_clk_rate;
+ u8 clkval;
+ int ret;
+ u8 ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl &= ~CLK_MASK;
+
+ ret = mpfs_generate_divisor(divisor, &clkval);
+
+ if (ret)
+ return -1;
+
+ ctrl |= clkval;
+
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ /* Reset controller */
+ mpfs_i2c_reset(idev);
+
+ return 0;
+}
+
+static void mpfs_i2c_transfer(struct mpfs_i2c_dev *idev, u32 data)
+{
+ if (idev->msg_len > 0)
+ writel(data, idev->base + MPFS_I2C_DATA);
+}
+
+static void mpfs_i2c_empty_rx(struct mpfs_i2c_dev *idev)
+{
+ u8 ctrl;
+
+ if (idev->msg_len > 0) {
+ *idev->buf++ = readl(idev->base + MPFS_I2C_DATA);
+ idev->msg_len--;
+ }
+
+ if (idev->msg_len == 0) {
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+ ctrl &= ~(1 << CTRL_AA);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+ }
+}
+
+static int mpfs_i2c_fill_tx(struct mpfs_i2c_dev *idev)
+{
+ mpfs_i2c_transfer(idev, *idev->buf++);
+ idev->msg_len--;
+
+ return 0;
+}
+
+static irqreturn_t mpfs_i2c_handle_isr(int irq, void *_dev)
+{
+ bool read, finish = false;
+ struct mpfs_i2c_dev *idev = _dev;
+ u32 status = idev->isr_status;
+ u8 ctrl;
+
+ if (!idev->buf) {
+ dev_warn(idev->dev, "unexpected interrupt\n");
+ return IRQ_HANDLED;
+ }
+
+ read = idev->msg_read ? 1 : 0;
+
+ switch (status) {
+ case STATUS_M_START_SENT:
+ case STATUS_M_REPEATED_START_SENT:
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+ ctrl &= ~(1 << CTRL_STA);
+ writel(idev->addr, idev->base + MPFS_I2C_DATA);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+ if (idev->msg_len <= 0)
+ finish = true;
+ break;
+ case STATUS_M_ARB_LOST:
+ /* handle Lost Arbitration */
+ idev->msg_err = -EAGAIN;
+ finish = true;
+ break;
+ case STATUS_M_SLAW_ACK:
+ if (idev->msg_len > 0) {
+ mpfs_i2c_fill_tx(idev);
+ } else {
+ /* On the last byte to be transmitted, send STOP */
+ mpfs_i2c_stop(idev);
+ finish = true;
+ }
+ break;
+ case STATUS_M_TX_DATA_NACK:
+ case STATUS_M_RX_DATA_NACKED:
+ case STATUS_M_SLAR_NACK:
+ case STATUS_M_SLAW_NACK:
+ idev->msg_err = -ENXIO;
+ mpfs_i2c_stop(idev);
+ finish = true;
+ break;
+ case STATUS_M_TX_DATA_ACK:
+ if (idev->msg_len > 0) {
+ mpfs_i2c_fill_tx(idev);
+ } else {
+ /* On the last byte to be transmitted, send STOP */
+ mpfs_i2c_stop(idev);
+ finish = true;
+ }
+ break;
+ case STATUS_M_SLAR_ACK:
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+ ctrl |= (1 << CTRL_AA);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+ if (idev->msg_len == 0) {
+ /* On the last byte to be transmitted, send STOP */
+ mpfs_i2c_stop(idev);
+ finish = true;
+ }
+ break;
+ case STATUS_M_RX_DATA_ACKED:
+ mpfs_i2c_empty_rx(idev);
+ if (idev->msg_len == 0) {
+ /* On the last byte to be transmitted, send STOP */
+ mpfs_i2c_stop(idev);
+ finish = true;
+ }
+ break;
+ default:
+ break;
+ }
+
+ if (finish) {
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+ ctrl &= ~(1 << CTRL_AA);
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+ complete(&idev->msg_complete);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t mpfs_i2c_isr(int irq, void *_dev)
+{
+ struct mpfs_i2c_dev *idev = _dev;
+ irqreturn_t ret = IRQ_NONE;
+ int si_bit = 0;
+
+ si_bit = readl(idev->base + MPFS_I2C_CTRL);
+ if (si_bit & (1 << CTRL_SI)) {
+ idev->isr_status = readl(idev->base + MPFS_I2C_STATUS);
+ ret = mpfs_i2c_handle_isr(irq, idev);
+ }
+
+ // Clear the si flag
+ mpfs_i2c_int_clear(idev);
+
+ return ret;
+}
+
+static int mpfs_i2c_xfer_msg(struct mpfs_i2c_dev *idev, struct i2c_msg *msg)
+{
+ u8 ctrl;
+ unsigned long time_left;
+
+ if (msg->len == 0)
+ return -EINVAL;
+
+ idev->addr = i2c_8bit_addr_from_msg(msg);
+ idev->msg_len = msg->len;
+ idev->buf = msg->buf;
+ idev->msg_err = 0;
+ idev->msg_read = (msg->flags & I2C_M_RD);
+
+ reinit_completion(&idev->msg_complete);
+
+ mpfs_i2c_core_enable(idev);
+
+ ctrl = readl(idev->base + MPFS_I2C_CTRL);
+
+ ctrl |= (1 << CTRL_STA);
+
+ writel(ctrl, idev->base + MPFS_I2C_CTRL);
+
+ time_left = wait_for_completion_timeout(&idev->msg_complete,
+ MICROCHIP_I2C_TIMEOUT);
+
+ if (time_left == 0)
+ return -ETIMEDOUT;
+
+ return idev->msg_err;
+}
+
+static int mpfs_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct mpfs_i2c_dev *idev = i2c_get_adapdata(adap);
+ int i, ret;
+
+ for (i = 0; i < num; i++) {
+ ret = mpfs_i2c_xfer_msg(idev, msgs++);
+ if (ret)
+ return ret;
+ }
+
+ return num;
+}
+
+static u32 mpfs_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm mpfs_i2c_algo = {
+ .master_xfer = mpfs_i2c_xfer,
+ .functionality = mpfs_i2c_func,
+};
+
+static int mpfs_i2c_probe(struct platform_device *pdev)
+{
+ struct mpfs_i2c_dev *idev = NULL;
+ struct resource *res;
+ int irq, ret;
+ u32 val;
+
+ idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
+ if (!idev)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ idev->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(idev->base))
+ return PTR_ERR(idev->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "missing interrupt resource\n");
+ return irq;
+ }
+
+ idev->i2c_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(idev->i2c_clk)) {
+ dev_err(&pdev->dev, "missing clock\n");
+ return PTR_ERR(idev->i2c_clk);
+ }
+
+ idev->dev = &pdev->dev;
+ init_completion(&idev->msg_complete);
+ spin_lock_init(&idev->lock);
+
+ val = device_property_read_u32(idev->dev, "clock-frequency",
+ &idev->bus_clk_rate);
+ if (val) {
+ dev_info(&pdev->dev, "default to 100kHz\n");
+ idev->bus_clk_rate = 100000; /* default clock rate */
+ }
+
+ if (idev->bus_clk_rate > 400000) {
+ dev_err(&pdev->dev, "invalid clock-frequency %d\n",
+ idev->bus_clk_rate);
+ return -EINVAL;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, mpfs_i2c_isr,
+ IRQF_SHARED, pdev->name, idev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to claim irq %d\n", irq);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(idev->i2c_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable clock\n");
+ return ret;
+ }
+
+ ret = mpfs_i2c_init(idev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to program clock divider\n");
+ return ret;
+ }
+
+ i2c_set_adapdata(&idev->adapter, idev);
+ snprintf(idev->adapter.name, sizeof(idev->adapter.name),
+ "Microchip I2C hw bus");
+ idev->adapter.owner = THIS_MODULE;
+ idev->adapter.algo = &mpfs_i2c_algo;
+ idev->adapter.dev.parent = &pdev->dev;
+ idev->adapter.dev.of_node = pdev->dev.of_node;
+
+ platform_set_drvdata(pdev, idev);
+
+ ret = i2c_add_adapter(&idev->adapter);
+ if (ret) {
+ clk_disable_unprepare(idev->i2c_clk);
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "Microchip I2C Probe Complete\n");
+
+ return 0;
+}
+
+static int mpfs_i2c_remove(struct platform_device *pdev)
+{
+ struct mpfs_i2c_dev *idev = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(idev->i2c_clk);
+ i2c_del_adapter(&idev->adapter);
+
+ return 0;
+}
+
+/* Match table for of_platform binding */
+static const struct of_device_id mpfs_i2c_of_match[] = {
+ { .compatible = "microchip,mpfs-i2c" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mpfs_i2c_of_match);
+
+static struct platform_driver mpfs_i2c_driver = {
+ .probe = mpfs_i2c_probe,
+ .remove = mpfs_i2c_remove,
+ .driver = {
+ .name = "microchip-mpfs-i2c",
+ .of_match_table = mpfs_i2c_of_match,
+ },
+};
+
+module_platform_driver(mpfs_i2c_driver);
+
+MODULE_DESCRIPTION("Microchip I2C bus driver");
+MODULE_AUTHOR("Microchip Corporation");
+MODULE_LICENSE("GPL v2");
--
2.25.1
