From: Wen Wang <wen.w.wang@xxxxxxxxx>
Initial release of the driver.
Major clean up by Alan Cox. This fixes the points raised in the initial
review except that
- some were no longer relevant
- speed is left 0/1/2 as specifying exact frequencies uses more command line
and makes it more complex for the user and for us - as we'd need to refuse
anything but the tested/verified speeds anyway
- the disable function doesn't do a totally time based delay - its ten times
the speed udelay so its clearly bounded anyway
Signed-off-by: Wen Wang <wen.w.wang@xxxxxxxxx>
Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
drivers/i2c/busses/Kconfig | 9
drivers/i2c/busses/Makefile | 1
drivers/i2c/busses/i2c-mrst.c | 1045 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 1055 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-mrst.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 29e01f6..ea0100e 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -420,6 +420,15 @@ config I2C_IXP2000
This driver is deprecated and will be dropped soon. Use i2c-gpio
instead.
+config I2C_MRST
+ tristate "Intel Moorestown/Medfield Platform I2C controller"
+ help
+ Say Y here if you have an Intel Moorestown/Medfield platform I2C
+ controller.
+
+ This support is also available as a module. If so, the module
+ will be called i2c-mrst.
+
config I2C_MPC
tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
depends on PPC32
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 936880b..0b9aa00 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
obj-$(CONFIG_I2C_IMX) += i2c-imx.o
obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o
+obj-$(CONFIG_I2C_MRST) += i2c-mrst.o
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
diff --git a/drivers/i2c/busses/i2c-mrst.c b/drivers/i2c/busses/i2c-mrst.c
new file mode 100644
index 0000000..862b4c2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mrst.c
@@ -0,0 +1,1045 @@
+/*
+ * Support for Moorestown/Medfield I2C chip
+ *
+ * Copyright (c) 2009 Intel Corporation.
+ * Copyright (c) 2009 Synopsys. Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License, version
+ * 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/stat.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+#define DRIVER_NAME "mrst_i2c"
+#define VERSION "Version 0.5"
+#define PLATFORM "Moorestown/Medfield"
+
+#define NUM_PLATFORMS 2
+/* Tables use: 0 Moorestown, 1 Medfield */
+
+enum platform_enum {
+ MOORESTOWN = 0,
+ MEDFIELD = 1,
+};
+
+struct mrst_i2c_private {
+ struct i2c_adapter adap;
+ /* Register base address */
+ void __iomem *base;
+ /* Speed mode */
+ int speed;
+ int pm_state;
+ struct completion complete;
+ int abort;
+ u8 *rx_buf;
+ int rx_buf_len;
+ int status;
+ struct i2c_msg *msg;
+ enum platform_enum platform;
+ struct mutex lock;
+ spinlock_t slock;
+};
+
+#define ACTIVE 0
+#define STANDBY 1
+
+#define STATUS_IDLE 0
+#define STATUS_READ_START 1
+#define STATUS_READ_IN_PROGRESS 2
+#define STATUS_READ_SUCCESS 3
+#define STATUS_WRITE_START 4
+#define STATUS_WRITE_SUCCESS 5
+#define STATUS_XFER_ABORT 6
+
+/* Control register */
+#define IC_CON 0x00
+#define SLV_DIS (1 << 6) /* Disable slave mode */
+#define RESTART (1 << 5) /* Send a Restart condition */
+#define ADDR_10BIT (1 << 4) /* 10-bit addressing */
+#define STANDARD_MODE (1 << 1) /* standard mode */
+#define FAST_MODE (2 << 1) /* fast mode */
+#define HIGH_MODE (3 << 1) /* high speed mode */
+#define MASTER_EN (1 << 0) /* Master mode */
+
+/* Target address register */
+#define IC_TAR 0x04
+#define IC_TAR_10BIT_ADDR (1 << 12) /* 10-bit addressing */
+#define IC_TAR_SPECIAL (1 << 11) /* Perform special I2C cmd */
+#define IC_TAR_GC_OR_START (1 << 10) /* 0: Gerneral Call Address */
+ /* 1: START BYTE */
+/* Slave Address Register */
+#define IC_SAR 0x08 /* Not used in Master mode */
+
+/* High Speed Master Mode Code Address Register */
+#define IC_HS_MADDR 0x0c
+
+/* Rx/Tx Data Buffer and Command Register */
+#define IC_DATA_CMD 0x10
+#define IC_RD (1 << 8) /* 1: Read 0: Write */
+
+/* Standard Speed Clock SCL High Count Register */
+#define IC_SS_SCL_HCNT 0x14
+
+/* Standard Speed Clock SCL Low Count Register */
+#define IC_SS_SCL_LCNT 0x18
+
+/* Fast Speed Clock SCL High Count Register */
+#define IC_FS_SCL_HCNT 0x1c
+
+/* Fast Spedd Clock SCL Low Count Register */
+#define IC_FS_SCL_LCNT 0x20
+
+/* High Speed Clock SCL High Count Register */
+#define IC_HS_SCL_HCNT 0x24
+
+/* High Speed Clock SCL Low Count Register */
+#define IC_HS_SCL_LCNT 0x28
+
+/* Interrupt Status Register */
+#define IC_INTR_STAT 0x2c /* Read only */
+#define R_GEN_CALL (1 << 11)
+#define R_START_DET (1 << 10)
+#define R_STOP_DET (1 << 9)
+#define R_ACTIVITY (1 << 8)
+#define R_RX_DONE (1 << 7)
+#define R_TX_ABRT (1 << 6)
+#define R_RD_REQ (1 << 5)
+#define R_TX_EMPTY (1 << 4)
+#define R_TX_OVER (1 << 3)
+#define R_RX_FULL (1 << 2)
+#define R_RX_OVER (1 << 1)
+#define R_RX_UNDER (1 << 0)
+
+/* Interrupt Mask Register */
+#define IC_INTR_MASK 0x30 /* Read and Write */
+#define M_GEN_CALL (1 << 11)
+#define M_START_DET (1 << 10)
+#define M_STOP_DET (1 << 9)
+#define M_ACTIVITY (1 << 8)
+#define M_RX_DONE (1 << 7)
+#define M_TX_ABRT (1 << 6)
+#define M_RD_REQ (1 << 5)
+#define M_TX_EMPTY (1 << 4)
+#define M_TX_OVER (1 << 3)
+#define M_RX_FULL (1 << 2)
+#define M_RX_OVER (1 << 1)
+#define M_RX_UNDER (1 << 0)
+
+/* Raw Interrupt Status Register */
+#define IC_RAW_INTR_STAT 0x34 /* Read Only */
+#define GEN_CALL (1 << 11) /* General call */
+#define START_DET (1 << 10) /* (RE)START occured */
+#define STOP_DET (1 << 9) /* STOP occured */
+#define ACTIVITY (1 << 8) /* Bus busy */
+#define RX_DONE (1 << 7) /* Not used in Master mode */
+#define TX_ABRT (1 << 6) /* Transmit Abort */
+#define RD_REQ (1 << 5) /* Not used in Master mode */
+#define TX_EMPTY (1 << 4) /* TX FIFO <= threshold */
+#define TX_OVER (1 << 3) /* TX FIFO overflow */
+#define RX_FULL (1 << 2) /* RX FIFO >= threshold */
+#define RX_OVER (1 << 1) /* RX FIFO overflow */
+#define RX_UNDER (1 << 0) /* RX FIFO empty */
+
+/* Receive FIFO Threshold Register */
+#define IC_RX_TL 0x38
+
+/* Transmit FIFO Treshold Register */
+#define IC_TX_TL 0x3c
+
+/* Clear Combined and Individual Interrupt Register */
+#define IC_CLR_INTR 0x40
+#define CLR_INTR (1 << 0)
+
+/* Clear RX_UNDER Interrupt Register */
+#define IC_CLR_RX_UNDER 0x44
+#define CLR_RX_UNDER (1 << 0)
+
+/* Clear RX_OVER Interrupt Register */
+#define IC_CLR_RX_OVER 0x48
+#define CLR_RX_OVER (1 << 0)
+
+/* Clear TX_OVER Interrupt Register */
+#define IC_CLR_TX_OVER 0x4c
+#define CLR_TX_OVER (1 << 0)
+
+#define IC_CLR_RD_REQ 0x50
+
+/* Clear TX_ABRT Interrupt Register */
+#define IC_CLR_TX_ABRT 0x54
+#define CLR_TX_ABRT (1 << 0)
+#define IC_CLR_RX_DONE 0x58
+
+/* Clear ACTIVITY Interrupt Register */
+#define IC_CLR_ACTIVITY 0x5c
+#define CLR_ACTIVITY (1 << 0)
+
+/* Clear STOP_DET Interrupt Register */
+#define IC_CLR_STOP_DET 0x60
+#define CLR_STOP_DET (1 << 0)
+
+/* Clear START_DET Interrupt Register */
+#define IC_CLR_START_DET 0x64
+#define CLR_START_DET (1 << 0)
+
+/* Clear GEN_CALL Interrupt Register */
+#define IC_CLR_GEN_CALL 0x68
+#define CLR_GEN_CALL (1 << 0)
+
+/* Enable Register */
+#define IC_ENABLE 0x6c
+#define ENABLE (1 << 0)
+
+/* Status Register */
+#define IC_STATUS 0x70 /* Read Only */
+#define STAT_SLV_ACTIVITY (1 << 6) /* Slave not in idle */
+#define STAT_MST_ACTIVITY (1 << 5) /* Master not in idle */
+#define STAT_RFF (1 << 4) /* RX FIFO Full */
+#define STAT_RFNE (1 << 3) /* RX FIFO Not Empty */
+#define STAT_TFE (1 << 2) /* TX FIFO Empty */
+#define STAT_TFNF (1 << 1) /* TX FIFO Not Full */
+#define STAT_ACTIVITY (1 << 0) /* Activity Status */
+
+/* Transmit FIFO Level Register */
+#define IC_TXFLR 0x74 /* Read Only */
+#define TXFLR (1 << 0) /* TX FIFO level */
+
+/* Receive FIFO Level Register */
+#define IC_RXFLR 0x78 /* Read Only */
+#define RXFLR (1 << 0) /* RX FIFO level */
+
+/* Transmit Abort Source Register */
+#define IC_TX_ABRT_SOURCE 0x80
+#define ABRT_SLVRD_INTX (1 << 15)
+#define ABRT_SLV_ARBLOST (1 << 14)
+#define ABRT_SLVFLUSH_TXFIFO (1 << 13)
+#define ARB_LOST (1 << 12)
+#define ABRT_MASTER_DIS (1 << 11)
+#define ABRT_10B_RD_NORSTRT (1 << 10)
+#define ABRT_SBYTE_NORSTRT (1 << 9)
+#define ABRT_HS_NORSTRT (1 << 8)
+#define ABRT_SBYTE_ACKDET (1 << 7)
+#define ABRT_HS_ACKDET (1 << 6)
+#define ABRT_GCALL_READ (1 << 5)
+#define ABRT_GCALL_NOACK (1 << 4)
+#define ABRT_TXDATA_NOACK (1 << 3)
+#define ABRT_10ADDR2_NOACK (1 << 2)
+#define ABRT_10ADDR1_NOACK (1 << 1)
+#define ABRT_7B_ADDR_NOACK (1 << 0)
+
+/* Enable Status Register */
+#define IC_ENABLE_STATUS 0x9c
+#define IC_EN (1 << 0) /* I2C in an enabled state */
+
+/* Component Parameter Register 1*/
+#define IC_COMP_PARAM_1 0xf4
+#define APB_DATA_WIDTH (0x3 << 0)
+
+/* added by xiaolin --begin */
+#define SS_MIN_SCL_HIGH 4000
+#define SS_MIN_SCL_LOW 4700
+#define FS_MIN_SCL_HIGH 600
+#define FS_MIN_SCL_LOW 1300
+#define HS_MIN_SCL_HIGH_100PF 60
+#define HS_MIN_SCL_LOW_100PF 120
+
+
+#define STANDARD 0
+#define FAST 1
+#define HIGH 2
+
+#define NUM_SPEEDS 3
+
+
+static int speed_mode[6] = {
+ STANDARD,
+ STANDARD,
+ STANDARD,
+ STANDARD,
+ STANDARD,
+ STANDARD
+};
+
+static int ctl_num;
+module_param_array(speed_mode, int, &ctl_num, S_IRUGO);
+MODULE_PARM_DESC(speed_mode, "Set the speed of the i2c interface (0-2)");
+
+static inline u32 mrst_i2c_read(void __iomem *reg)
+{
+ return __raw_readl(reg);
+}
+
+static inline void mrst_i2c_write(void __iomem *reg, u32 val)
+{
+ __raw_writel(val, reg);
+}
+
+/**
+ * mrst_i2c_disable - Disable I2C controller
+ * @adap: struct pointer to i2c_adapter
+ *
+ * Return Value:
+ * 0 success
+ * -EBUSY if device is busy
+ * -ETIMEOUT if i2c cannot be disabled within the given time
+ *
+ * I2C bus state should be checked prior to disabling the hardware. If bus is
+ * not in idle state, an errno is returned. Write "0" to IC_ENABLE to disable
+ * I2C controller.
+ */
+static int mrst_i2c_disable(struct i2c_adapter *adap)
+{
+ struct mrst_i2c_private *i2c = i2c_get_adapdata(adap);
+ int err = 0;
+ int count = 0;
+ int ret1, ret2;
+ static const u16 delay[NUM_SPEEDS] = {100, 25, 3};
+
+ /* Set IC_ENABLE to 0 */
+ mrst_i2c_write(i2c->base + IC_ENABLE, 0);
+
+ /* Check if device is busy */
+ dev_dbg(&adap->dev, "mrst i2c disable\n");
+ while ((ret1 = mrst_i2c_read(i2c->base + IC_ENABLE_STATUS) & 0x1)
+ || (ret2 = mrst_i2c_read(i2c->base + IC_STATUS) & 0x1)) {
+ udelay(delay[i2c->speed]);
+ mrst_i2c_write(i2c->base + IC_ENABLE, 0);
+ dev_dbg(&adap->dev, "i2c is busy, count is %d speed %d\n",
+ count, i2c->speed);
+ if (count++ > 10) {
+ err = -ETIMEDOUT;
+ break;
+ }
+ }
+
+ /* Clear all interrupts */
+ mrst_i2c_read(i2c->base + IC_CLR_INTR);
+ /* Disable all interupts */
+ mrst_i2c_write(i2c->base + IC_INTR_MASK, 0x0000);
+
+ return err;
+}
+
+/**
+ * mrst_i2c_hwinit - Initiate the I2C hardware registers. This function will
+ * be called in mrst_i2c_probe() before device registration.
+ * @dev: pci device struct pointer
+ *
+ * Return Values:
+ * 0 success
+ * -EBUSY i2c cannot be disabled
+ * -ETIMEDOUT i2c cannot be disabled
+ * -EFAULT If APB data width is not 32-bit wide
+ *
+ * I2C should be disabled prior to other register operation. If failed, an
+ * errno is returned. Mask and Clear all interrpts, this should be done at
+ * first. Set common registers which will not be modified during normal
+ * transfers, including: controll register, FIFO threshold and clock freq.
+ * Check APB data width at last.
+ */
+static int mrst_i2c_hwinit(struct mrst_i2c_private *i2c)
+{
+ int err;
+
+ static const u16 hcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
+ { 0x75, 0x15, 0x07 },
+ { 0x1EC, 0x70, 0x06 }
+ };
+ static const u16 lcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
+ { 0x7C, 0x21, 0x0E },
+ { 0x1F3, 0x81, 0x0F }
+ };
+
+ /* Disable i2c first */
+ err = mrst_i2c_disable(&i2c->adap);
+ if (err)
+ return err;
+
+ /*
+ * Setup clock frequency and speed mode
+ * Enable restart condition,
+ * enable master FSM, disable slave FSM,
+ * use target address when initiating transfer
+ */
+
+ mrst_i2c_write(i2c->base + IC_CON,
+ (i2c->speed + 1) << 1 | SLV_DIS | RESTART | MASTER_EN);
+ mrst_i2c_write(i2c->base + (IC_SS_SCL_HCNT + (i2c->speed << 3)),
+ hcnt[i2c->platform][i2c->speed]);
+ mrst_i2c_write(i2c->base + (IC_SS_SCL_LCNT + (i2c->speed << 3)),
+ lcnt[i2c->platform][i2c->speed]);
+
+ /* Set tranmit & receive FIFO threshold to zero */
+ mrst_i2c_write(i2c->base + IC_RX_TL, 0x0);
+ mrst_i2c_write(i2c->base + IC_TX_TL, 0xFF);
+
+ return 0;
+}
+
+/**
+ * mrst_i2c_func - Return the supported three I2C operations.
+ * @adapter: i2c_adapter struct pointer
+ */
+static u32 mrst_i2c_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
+}
+
+/**
+ * mrst_i2c_address_neq - To check if the addresses for different i2c messages
+ * are equal.
+ * @p1: first i2c_msg
+ * @p2: second i2c_msg
+ *
+ * Return Values:
+ * 0 if addresses are equal
+ * 1 if not equal
+ *
+ * Within a single transfer, I2C client may need to send its address more
+ * than one time. So a check if the addresses match is needed.
+ */
+static inline int mrst_i2c_address_neq(const struct i2c_msg *p1,
+ const struct i2c_msg *p2)
+{
+ if (p1->addr != p2->addr)
+ return 1;
+ if ((p1->flags ^ p2->flags) & I2C_M_TEN)
+ return 1;
+ return 0;
+}
+
+/**
+ * mrst_i2c_abort - To handle transfer abortions and print error messages.
+ * @adap: i2c_adapter struct pointer
+ *
+ * By reading register IC_TX_ABRT_SOURCE, various transfer errors can be
+ * distingushed. At present, no circumstances have been found out that
+ * multiple errors would be occured simutaneously, so we simply use the
+ * register value directly.
+ *
+ * At last the error bits are cleared. (Note clear ABRT_SBYTE_NORSTRT bit need
+ * a few extra steps)
+ */
+static void mrst_i2c_abort(struct mrst_i2c_private *i2c)
+{
+ /* Read about source register */
+ int abort = i2c->abort;
+ struct i2c_adapter *adap = &i2c->adap;
+
+ /* Single transfer error check:
+ * According to databook, TX/RX FIFOs would be flushed when
+ * the abort interrupt occured.
+ */
+ if (abort & ABRT_MASTER_DIS)
+ dev_err(&adap->dev,
+ "initiate master operation with master mode disabled.\n");
+ if (abort & ABRT_10B_RD_NORSTRT)
+ dev_err(&adap->dev,
+ "RESTART disabled and master sent READ cmd in 10-bit addressing.\n");
+ if (abort & ABRT_SBYTE_NORSTRT) {
+ dev_err(&adap->dev,
+ "RESTART disabled and user is trying to send START byte.\n");
+ mrst_i2c_write(i2c->base + IC_TX_ABRT_SOURCE,
+ ~ABRT_SBYTE_NORSTRT);
+ mrst_i2c_write(i2c->base + IC_CON, RESTART);
+ mrst_i2c_write(i2c->base + IC_TAR, ~IC_TAR_SPECIAL);
+ }
+
+ if (abort & ABRT_SBYTE_ACKDET)
+ dev_err(&adap->dev,
+ "START byte was acknowledged.\n");
+ if (abort & ABRT_TXDATA_NOACK)
+ dev_err(&adap->dev,
+ "No acknowledgement received from slave.\n");
+ if (abort & ABRT_10ADDR2_NOACK)
+ dev_dbg(&adap->dev,
+ "The 2nd address byte of the 10-bit address was not acknowledged.\n");
+ if (abort & ABRT_10ADDR1_NOACK)
+ dev_dbg(&adap->dev,
+ "The 1st address byte of 10-bit address was not acknowledged.\n");
+ if (abort & ABRT_7B_ADDR_NOACK)
+ dev_dbg(&adap->dev,
+ "I2C slave device not acknowledged.\n");
+
+ /* Clear TX_ABRT bit */
+ mrst_i2c_read(i2c->base + IC_CLR_TX_ABRT);
+ i2c->status = STATUS_XFER_ABORT;
+}
+
+/**
+ * xfer_read - Internal function to implement master read transfer.
+ * @adap: i2c_adapter struct pointer
+ * @buf: buffer in i2c_msg
+ * @length: number of bytes to be read
+ *
+ * Return Values:
+ * 0 if the read transfer succeeds
+ * -ETIMEDOUT if cannot read the "raw" interrupt register
+ * -EINVAL if transfer abort occured
+ *
+ * For every byte, a "READ" command will be loaded into IC_DATA_CMD prior to
+ * data transfer. The actual "read" operation will be performed if the RX_FULL
+ * interrupt is occurred.
+ *
+ * Note there may be two interrupt signals captured, one should read
+ * IC_RAW_INTR_STAT to seperate between errors and actual data.
+ */
+static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+ struct mrst_i2c_private *i2c = i2c_get_adapdata(adap);
+ int i = length;
+ int err;
+
+ mrst_i2c_write(i2c->base + IC_INTR_MASK, 0x0044);
+ mrst_i2c_read(i2c->base + IC_CLR_INTR);
+
+ if (length >= 256) {
+ dev_err(&adap->dev,
+ "I2C FIFO cannot support larger than 256 bytes\n");
+ return -EMSGSIZE;
+ }
+
+ INIT_COMPLETION(i2c->complete);
+
+ while (i--)
+ mrst_i2c_write(i2c->base + IC_DATA_CMD, IC_RD);
+
+ i2c->status = STATUS_READ_START;
+ err = wait_for_completion_interruptible_timeout(&i2c->complete, HZ);
+ if (!err) {
+ dev_err(&adap->dev, "Timeout for ACK from I2C slave device\n");
+ mrst_i2c_hwinit(i2c);
+ return -ETIMEDOUT;
+ } else {
+ if (i2c->status == STATUS_READ_SUCCESS)
+ return 0;
+ else
+ return -EIO;
+ }
+}
+
+/**
+ * xfer_write - Internal function to implement master write transfer.
+ * @adap: i2c_adapter struct pointer
+ * @buf: buffer in i2c_msg
+ * @length: number of bytes to be read
+ *
+ * Return Values:
+ * 0 if the read transfer succeeds
+ * -ETIMEDOUT if cannot read the "raw" interrupt register
+ * -EINVAL if transfer abort occured
+ *
+ * For every byte, a "WRITE" command will be loaded into IC_DATA_CMD prior to
+ * data transfer. The actual "write" operation will be performed when the
+ * RX_FULL interrupt signal occurs.
+ *
+ * Note there may be two interrupt signals captured, one should read
+ * IC_RAW_INTR_STAT to separate between errors and actual data.
+ */
+static int xfer_write(struct i2c_adapter *adap,
+ unsigned char *buf, int length)
+{
+ struct mrst_i2c_private *i2c = i2c_get_adapdata(adap);
+ int i, err;
+
+ mrst_i2c_write(i2c->base + IC_INTR_MASK, 0x0050);
+ mrst_i2c_read(i2c->base + IC_CLR_INTR);
+
+ if (length >= 256) {
+ dev_err(&adap->dev,
+ "I2C FIFO cannot support larger than 256 bytes\n");
+ return -EMSGSIZE;
+ }
+
+ INIT_COMPLETION(i2c->complete);
+ for (i = 0; i < length; i++)
+ mrst_i2c_write(i2c->base + IC_DATA_CMD,
+ (uint16_t)(*(buf + i)));
+
+ i2c->status = STATUS_WRITE_START;
+ err = wait_for_completion_interruptible_timeout(&i2c->complete, HZ);
+ if (!err) {
+ dev_err(&adap->dev, "Timeout for ACK from I2C slave device\n");
+ mrst_i2c_hwinit(i2c);
+ return -ETIMEDOUT;
+ } else {
+ if (i2c->status == STATUS_WRITE_SUCCESS)
+ return 0;
+ else
+ return -EIO;
+ }
+}
+
+static int mrst_i2c_setup(struct i2c_adapter *adap, struct i2c_msg *pmsg)
+{
+ struct mrst_i2c_private *i2c = i2c_get_adapdata(adap);
+ int err;
+ u32 reg;
+ u32 bit_mask;
+ u32 mode;
+
+ /* Disable device first */
+ err = mrst_i2c_disable(adap);
+ if (err) {
+ dev_err(&adap->dev,
+ "Cannot disable i2c controller, timeout\n");
+ return err;
+ }
+
+ mode = (1 + i2c->speed) << 1;
+ /* set the speed mode */
+ reg = mrst_i2c_read(i2c->base + IC_CON);
+ if ((reg & 0x06) != mode) {
+ dev_dbg(&adap->dev, "set mode %d\n", i2c->speed);
+ mrst_i2c_write(i2c->base + IC_CON,
+ (reg & (~0x6)) | mode);
+ }
+
+ reg = mrst_i2c_read(i2c->base + IC_CON);
+ /* use 7-bit addressing */
+ if (pmsg->flags & I2C_M_TEN) {
+ if ((reg & (1<<4)) != ADDR_10BIT) {
+ dev_dbg(&adap->dev, "set i2c 10 bit address mode\n");
+ mrst_i2c_write(i2c->base + IC_CON,
+ reg | ADDR_10BIT);
+ }
+ } else {
+ if ((reg & (1<<4)) != 0x0) {
+ dev_dbg(&adap->dev, "set i2c 7 bit address mode\n");
+ mrst_i2c_write(i2c->base + IC_CON, reg & (~(1<<4)));
+ }
+ }
+ /* enable restart conditions */
+ reg = mrst_i2c_read(i2c->base + IC_CON);
+ if ((reg & (1<<5)) != 1<<5) {
+ dev_dbg(&adap->dev, "enable restart conditions\n");
+ mrst_i2c_write(i2c->base + IC_CON, (reg & (~(1 << 5)))
+ | 1 << 5);
+ }
+
+ /* enable master FSM */
+ reg = mrst_i2c_read(i2c->base + IC_CON);
+ dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
+ if ((reg & (1<<6)) != 1<<6) {
+ dev_dbg(&adap->dev, "enable master FSM\n");
+ mrst_i2c_write(i2c->base + IC_CON, (reg & (~(1 << 6)))
+ | 1<<6);
+ dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
+ }
+
+ /* use target address when initiating transfer */
+ reg = mrst_i2c_read(i2c->base + IC_TAR);
+ bit_mask = 1 << 11 | 1 << 10;
+
+ if ((reg & bit_mask) != 0x0) {
+ dev_dbg(&adap->dev,
+ "WR: use target address when intiating transfer, i2c_tx_target\n");
+ mrst_i2c_write(i2c->base + IC_TAR, reg & ~bit_mask);
+ }
+
+ /* set target address to the I2C slave address */
+ dev_dbg(&adap->dev,
+ "set target address to the I2C slave address, addr is %x\n",
+ pmsg->addr);
+ mrst_i2c_write(i2c->base + IC_TAR, pmsg->addr
+ | (pmsg->flags & I2C_M_TEN ? IC_TAR_10BIT_ADDR : 0));
+
+ /* Enable I2C controller */
+ mrst_i2c_write(i2c->base + IC_ENABLE, ENABLE);
+
+ return 0;
+}
+
+/**
+ * mrst_i2c_xfer - Main master transfer routine.
+ * @adap: i2c_adapter struct pointer
+ * @pmsg: i2c_msg struct pointer
+ * @num: number of i2c_msg
+ *
+ * Return Values:
+ * + number of messages transfered
+ * -ETIMEDOUT If cannot disable I2C controller or read IC_STATUS
+ * -EINVAL If the address in i2c_msg is invalid
+ *
+ * This function will be registered in i2c-core and exposed to external
+ * I2C clients.
+ * 1. Disable I2C controller
+ * 2. Unmask three interrupts: RX_FULL, TX_EMPTY, TX_ABRT
+ * 3. Check if address in i2c_msg is valid
+ * 4. Enable I2C controller
+ * 5. Perform real transfer (call xfer_read or xfer_write)
+ * 6. Wait until the current transfer is finished (check bus state)
+ * 7. Mask and clear all interrupts
+ */
+static int mrst_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *pmsg,
+ int num)
+{
+ struct mrst_i2c_private *i2c = i2c_get_adapdata(adap);
+ int i, err;
+
+ mutex_lock(&i2c->lock);
+ dev_dbg(&adap->dev, "mrst_i2c_xfer, process %d msg(s)\n", num);
+ dev_dbg(&adap->dev, "slave address is %x\n", pmsg->addr);
+
+ if (i2c->pm_state == STANDBY) {
+ dev_err(&adap->dev, "Adapter %d in standby\n", adap->nr);
+ mutex_unlock(&i2c->lock);
+ return -1;
+ }
+
+ /* if number of messages equal 0*/
+ if (num == 0) {
+ mutex_unlock(&i2c->lock);
+ return 0;
+ }
+
+ for (i = 1; i < num; i++) {
+ /* Message address equal? */
+ if (unlikely(mrst_i2c_address_neq(&pmsg[0], &pmsg[i]))) {
+ dev_err(&adap->dev, "Invalid address in msg[%d]\n", i);
+ mutex_unlock(&i2c->lock);
+ return -EINVAL;
+ }
+ }
+
+ if (mrst_i2c_setup(adap, pmsg)) {
+ mutex_unlock(&i2c->lock);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num; i++) {
+ i2c->msg = pmsg;
+ i2c->status = STATUS_IDLE;
+ /* Read or Write */
+ if (pmsg->flags & I2C_M_RD) {
+ dev_dbg(&adap->dev, "I2C_M_RD\n");
+ err = xfer_read(adap, pmsg->buf, pmsg->len);
+ } else {
+ dev_dbg(&adap->dev, "I2C_M_WR\n");
+ err = xfer_write(adap, pmsg->buf, pmsg->len);
+ }
+ if (err < 0)
+ goto err_1;
+ dev_dbg(&adap->dev, "msg[%d] transfer complete\n", i);
+ pmsg++; /* next message */
+ }
+ goto exit;
+
+err_1:
+ i = err;
+exit:
+ /* Mask interrupts */
+ mrst_i2c_write(i2c->base + IC_INTR_MASK, 0x0000);
+ /* Clear all interrupts */
+ mrst_i2c_read(i2c->base + IC_CLR_INTR);
+
+ mutex_unlock(&i2c->lock);
+
+ return i;
+}
+
+static void i2c_isr_read(struct mrst_i2c_private *i2c)
+{
+ struct i2c_msg *msg = i2c->msg;
+ int rx_num;
+ u32 len;
+ u8 *buf;
+
+ if (!(msg->flags & I2C_M_RD))
+ return;
+
+ if (i2c->status != STATUS_READ_IN_PROGRESS) {
+ len = msg->len;
+ buf = msg->buf;
+ } else {
+ len = i2c->rx_buf_len;
+ buf = i2c->rx_buf;
+ }
+
+ rx_num = mrst_i2c_read(i2c->base + IC_RXFLR);
+
+ for (; len > 0 && rx_num > 0; len--, rx_num--)
+ *buf++ = mrst_i2c_read(i2c->base + IC_DATA_CMD);
+
+ if (len > 0) {
+ i2c->status = STATUS_READ_IN_PROGRESS;
+ i2c->rx_buf_len = len;
+ i2c->rx_buf = buf;
+ } else
+ i2c->status = STATUS_READ_SUCCESS;
+
+ return;
+}
+
+static irqreturn_t mrst_i2c_isr(int this_irq, void *dev)
+{
+ struct mrst_i2c_private *i2c = dev;
+ u32 stat = mrst_i2c_read(i2c->base + IC_INTR_STAT) & 0x54;
+
+ dev_dbg(&i2c->adap.dev, "%s, stat = 0x%x\n", __func__, stat);
+
+ if (i2c->status != STATUS_WRITE_START &&
+ i2c->status != STATUS_READ_START &&
+ i2c->status != STATUS_READ_IN_PROGRESS)
+ goto err;
+
+ if (stat & TX_ABRT)
+ i2c->abort = mrst_i2c_read(i2c->base + IC_TX_ABRT_SOURCE);
+
+ mrst_i2c_read(i2c->base + IC_CLR_INTR);
+
+ if (stat & TX_ABRT) {
+ mrst_i2c_abort(i2c);
+ goto exit;
+ }
+
+ if (stat & RX_FULL) {
+ i2c_isr_read(i2c);
+ goto exit;
+ }
+
+ if (stat & TX_EMPTY) {
+ if (mrst_i2c_read(i2c->base + IC_STATUS) & 0x4)
+ i2c->status = STATUS_WRITE_SUCCESS;
+ }
+
+exit:
+ if (i2c->status == STATUS_READ_SUCCESS ||
+ i2c->status == STATUS_WRITE_SUCCESS ||
+ i2c->status == STATUS_XFER_ABORT)
+ complete(&i2c->complete);
+err:
+ return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm mrst_i2c_algorithm = {
+ .master_xfer = mrst_i2c_xfer,
+ .functionality = mrst_i2c_func,
+};
+
+/**
+ * mrst_i2c_probe - I2C controller initialization routine
+ * @dev: pci device
+ * @id: device id
+ *
+ * Return Values:
+ * 0 success
+ * -ENODEV If cannot allocate pci resource
+ * -ENOMEM If the register base remapping failed, or
+ * if kzalloc failed
+ *
+ * Initialization steps:
+ * 1. Request for PCI resource
+ * 2. Remap the start address of PCI resource to register base
+ * 3. Request for device memory region
+ * 4. Fill in the struct members of mrst_i2c_private
+ * 5. Call mrst_i2c_hwinit() for hardware initialization
+ * 6. Register I2C adapter in i2c-core
+ */
+static int __devinit mrst_i2c_probe(struct pci_dev *dev,
+ const struct pci_device_id *id)
+{
+ struct mrst_i2c_private *mrst;
+ unsigned long start, len;
+ int err, busnum;
+ void __iomem *base = NULL;
+
+ dev_dbg(&dev->dev, "Get into probe function for I2C\n");
+ err = pci_enable_device(dev);
+ if (err) {
+ dev_err(&dev->dev, "Failed to enable I2C PCI device (%d)\n",
+ err);
+ goto exit;
+ }
+
+ /* Determine the address of the I2C area */
+ start = pci_resource_start(dev, 0);
+ len = pci_resource_len(dev, 0);
+ if (!start || len == 0) {
+ dev_err(&dev->dev, "base address not set\n");
+ err = -ENODEV;
+ goto exit;
+ }
+ dev_dbg(&dev->dev, "%s i2c resource start 0x%lx, len=%ld\n",
+ PLATFORM, start, len);
+
+ err = pci_request_region(dev, 0, DRIVER_NAME);
+ if (err) {
+ dev_err(&dev->dev, "failed to request I2C region "
+ "0x%lx-0x%lx\n", start,
+ (unsigned long)pci_resource_end(dev, 0));
+ goto exit;
+ }
+
+ base = ioremap_nocache(start, len);
+ if (!base) {
+ dev_err(&dev->dev, "I/O memory remapping failed\n");
+ err = -ENOMEM;
+ goto fail0;
+ }
+
+ /* Allocate the per-device data structure, mrst_i2c_private */
+ mrst = kzalloc(sizeof(struct mrst_i2c_private), GFP_KERNEL);
+ if (mrst == NULL) {
+ dev_err(&dev->dev, "can't allocate interface\n");
+ err = -ENOMEM;
+ goto fail1;
+ }
+
+ /* Initialize struct members */
+ snprintf(mrst->adap.name, sizeof(&mrst->adap.name),
+ "MRST/Medfield I2C at %lx", start);
+ mrst->adap.owner = THIS_MODULE;
+ mrst->adap.algo = &mrst_i2c_algorithm;
+ mrst->adap.dev.parent = &dev->dev;
+ mrst->base = base;
+ mrst->speed = STANDARD;
+ mrst->pm_state = ACTIVE;
+ mrst->abort = 0;
+ mrst->rx_buf_len = 0;
+ mrst->status = STATUS_IDLE;
+
+ pci_set_drvdata(dev, mrst);
+ i2c_set_adapdata(&mrst->adap, mrst);
+
+ mrst->adap.nr = busnum = id->driver_data;
+ if (dev->device <= 0x0804)
+ mrst->platform = MOORESTOWN;
+ else
+ mrst->platform = MEDFIELD;
+
+ dev_dbg(&dev->dev, "I2C%d\n", busnum);
+
+ if (ctl_num > busnum) {
+ if (speed_mode[busnum] < 0 || speed_mode[busnum] >= NUM_SPEEDS)
+ dev_warn(&dev->dev, "invalid speed %d ignored.\n",
+ speed_mode[busnum]);
+ else
+ mrst->speed = speed_mode[busnum];
+ }
+
+ /* Initialize i2c controller */
+ err = mrst_i2c_hwinit(mrst);
+ if (err < 0) {
+ dev_err(&dev->dev, "I2C interface initialization failed\n");
+ goto fail2;
+ }
+
+ mutex_init(&mrst->lock);
+ init_completion(&mrst->complete);
+ err = request_irq(dev->irq, mrst_i2c_isr, IRQF_DISABLED,
+ mrst->adap.name, mrst);
+ if (err) {
+ dev_err(&dev->dev, "failed to request IRQ for I2C controller: "
+ "%s", mrst->adap.name);
+ goto fail2;
+ }
+ /* Clear all interrupts */
+ mrst_i2c_read(mrst->base + IC_CLR_INTR);
+ mrst_i2c_write(mrst->base + IC_INTR_MASK, 0x0000);
+
+ /* Adapter registration */
+ err = i2c_add_numbered_adapter(&mrst->adap);
+ if (err) {
+ dev_err(&dev->dev, "adapter %s registration failed\n",
+ mrst->adap.name);
+ goto fail3;
+ }
+
+ dev_dbg(&dev->dev, "%s I2C bus %d driver bind success.\n",
+ (mrst->platform == MOORESTOWN) ? "Moorestown" : "Medfield",
+ busnum);
+ return 0;
+
+fail3:
+ free_irq(dev->irq, mrst);
+fail2:
+ pci_set_drvdata(dev, NULL);
+ kfree(mrst);
+fail1:
+ iounmap(base);
+fail0:
+ pci_release_region(dev, 0);
+exit:
+ return err;
+}
+
+static void __devexit mrst_i2c_remove(struct pci_dev *dev)
+{
+ struct mrst_i2c_private *mrst = (struct mrst_i2c_private *)
+ pci_get_drvdata(dev);
+ mrst_i2c_disable(&mrst->adap);
+ if (i2c_del_adapter(&mrst->adap))
+ dev_err(&dev->dev, "Failed to delete i2c adapter");
+
+ free_irq(dev->irq, mrst);
+ pci_set_drvdata(dev, NULL);
+ iounmap(mrst->base);
+ kfree(mrst);
+ pci_release_region(dev, 0);
+}
+
+static struct pci_device_id mrst_i2c_ids[] = {
+ /* Moorestown */
+ {PCI_VDEVICE(INTEL, 0x0802), 0 },
+ {PCI_VDEVICE(INTEL, 0x0803), 1 },
+ {PCI_VDEVICE(INTEL, 0x0804), 2 },
+ /* Medfield */
+ {PCI_VDEVICE(INTEL, 0x0817), 3,},
+ {PCI_VDEVICE(INTEL, 0x0818), 4 },
+ {PCI_VDEVICE(INTEL, 0x0819), 5 },
+ {PCI_VDEVICE(INTEL, 0x082C), 0 },
+ {PCI_VDEVICE(INTEL, 0x082D), 1 },
+ {PCI_VDEVICE(INTEL, 0x082E), 2 },
+ {0,}
+};
+MODULE_DEVICE_TABLE(pci, mrst_i2c_ids);
+
+static struct pci_driver mrst_i2c_driver = {
+ .name = DRIVER_NAME,
+ .id_table = mrst_i2c_ids,
+ .probe = mrst_i2c_probe,
+ .remove = __devexit_p(mrst_i2c_remove),
+};
+
+static int __init mrst_i2c_init(void)
+{
+ return pci_register_driver(&mrst_i2c_driver);
+}
+
+static void __exit mrst_i2c_exit(void)
+{
+ pci_unregister_driver(&mrst_i2c_driver);
+}
+
+module_init(mrst_i2c_init);
+module_exit(mrst_i2c_exit);
+
+MODULE_AUTHOR("Ba Zheng <zheng.ba@xxxxxxxxx>");
+MODULE_DESCRIPTION("I2C driver for Moorestown Platform");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(VERSION);
--
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