- 根目录:
- drivers
- i2c
- busses
- i2c-intel-mid.c
/*
* 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/kernel.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/pm_runtime.h>
#include <linux/io.h>
#define DRIVER_NAME "i2c-intel-mid"
#define VERSION "Version 0.5ac2"
#define PLATFORM "Moorestown/Medfield"
/* Tables use: 0 Moorestown, 1 Medfield */
#define NUM_PLATFORMS 2
enum platform_enum {
MOORESTOWN = 0,
MEDFIELD = 1,
};
enum mid_i2c_status {
STATUS_IDLE = 0,
STATUS_READ_START,
STATUS_READ_IN_PROGRESS,
STATUS_READ_SUCCESS,
STATUS_WRITE_START,
STATUS_WRITE_SUCCESS,
STATUS_XFER_ABORT,
STATUS_STANDBY
};
/**
* struct intel_mid_i2c_private - per device I²C context
* @adap: core i2c layer adapter information
* @dev: device reference for power management
* @base: register base
* @speed: speed mode for this port
* @complete: completion object for transaction wait
* @abort: reason for last abort
* @rx_buf: pointer into working receive buffer
* @rx_buf_len: receive buffer length
* @status: adapter state machine
* @msg: the message we are currently processing
* @platform: the MID device type we are part of
* @lock: transaction serialization
*
* We allocate one of these per device we discover, it holds the core
* i2c layer objects and the data we need to track privately.
*/
struct intel_mid_i2c_private {
struct i2c_adapter adap;
struct device *dev;
void __iomem *base;
int speed;
struct completion complete;
int abort;
u8 *rx_buf;
int rx_buf_len;
enum mid_i2c_status status;
struct i2c_msg *msg;
enum platform_enum platform;
struct mutex lock;
};
#define NUM_SPEEDS 3
#define ACTIVE 0
#define STANDBY 1
/* 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 occurred */
#define STOP_DET (1 << 9) /* STOP occurred */
#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] = {
FAST,
FAST,
FAST,
STANDARD,
FAST,
FAST
};
static int ctl_num = 6;
module_param_array(speed_mode, int, &ctl_num, S_IRUGO);
MODULE_PARM_DESC(speed_mode, "Set the speed of the i2c interface (0-2)");
/**
* intel_mid_i2c_disable - Disable I2C controller
* @adap: struct pointer to i2c_adapter
*
* Return Value:
* 0 success
* -EBUSY if device is busy
* -ETIMEDOUT 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 intel_mid_i2c_disable(struct i2c_adapter *adap)
{
struct intel_mid_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 */
writel(0, i2c->base + IC_ENABLE);
/* Check if device is busy */
dev_dbg(&adap->dev, "mrst i2c disable\n");
while ((ret1 = readl(i2c->base + IC_ENABLE_STATUS) & 0x1)
|| (ret2 = readl(i2c->base + IC_STATUS) & 0x1)) {
udelay(delay[i2c->speed]);
writel(0, i2c->base + IC_ENABLE);
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 */
readl(i2c->base + IC_CLR_INTR);
readl(i2c->base + IC_CLR_STOP_DET);
readl(i2c->base + IC_CLR_START_DET);
readl(i2c->base + IC_CLR_ACTIVITY);
readl(i2c->base + IC_CLR_TX_ABRT);
readl(i2c->base + IC_CLR_RX_OVER);
readl(i2c->base + IC_CLR_RX_UNDER);
readl(i2c->base + IC_CLR_TX_OVER);
readl(i2c->base + IC_CLR_RX_DONE);
readl(i2c->base + IC_CLR_GEN_CALL);
/* Disable all interupts */
writel(0x0000, i2c->base + IC_INTR_MASK);
return err;
}
/**
* intel_mid_i2c_hwinit - Initialize the I2C hardware registers
* @dev: pci device struct pointer
*
* This function will be called in intel_mid_i2c_probe() before device
* registration.
*
* 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: control register, FIFO threshold and clock freq.
* Check APB data width at last.
*/
static int intel_mid_i2c_hwinit(struct intel_mid_i2c_private *i2c)
{
int err;
static const u16 hcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
{ 0x75, 0x15, 0x07 },
{ 0x04c, 0x10, 0x06 }
};
static const u16 lcnt[NUM_PLATFORMS][NUM_SPEEDS] = {
{ 0x7C, 0x21, 0x0E },
{ 0x053, 0x19, 0x0F }
};
/* Disable i2c first */
err = intel_mid_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
*/
writel((i2c->speed + 1) << 1 | SLV_DIS | RESTART | MASTER_EN,
i2c->base + IC_CON);
writel(hcnt[i2c->platform][i2c->speed],
i2c->base + (IC_SS_SCL_HCNT + (i2c->speed << 3)));
writel(lcnt[i2c->platform][i2c->speed],
i2c->base + (IC_SS_SCL_LCNT + (i2c->speed << 3)));
/* Set tranmit & receive FIFO threshold to zero */
writel(0x0, i2c->base + IC_RX_TL);
writel(0x0, i2c->base + IC_TX_TL);
return 0;
}
/**
* intel_mid_i2c_func - Return the supported three I2C operations.
* @adapter: i2c_adapter struct pointer
*/
static u32 intel_mid_i2c_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
}
/**
* intel_mid_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, the I2C client may need to send its address more
* than once. So a check if the addresses match is needed.
*/
static inline bool intel_mid_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;
}
/**
* intel_mid_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 occurred 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 intel_mid_i2c_abort(struct intel_mid_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 occurred.
*/
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");
writel(~ABRT_SBYTE_NORSTRT, i2c->base + IC_TX_ABRT_SOURCE);
writel(RESTART, i2c->base + IC_CON);
writel(~IC_TAR_SPECIAL, i2c->base + IC_TAR);
}
if (abort & ABRT_SBYTE_ACKDET)
dev_err(&adap->dev,
"START byte was not acknowledged.\n");
if (abort & ABRT_TXDATA_NOACK)
dev_dbg(&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 */
readl(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 a transfer abort occurred
*
* 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 an RX_FULL
* interrupt occurred.
*
* 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_read(struct i2c_adapter *adap, unsigned char *buf, int length)
{
struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
int i = length;
int err;
if (length >= 256) {
dev_err(&adap->dev,
"I2C FIFO cannot support larger than 256 bytes\n");
return -EMSGSIZE;
}
INIT_COMPLETION(i2c->complete);
readl(i2c->base + IC_CLR_INTR);
writel(0x0044, i2c->base + IC_INTR_MASK);
i2c->status = STATUS_READ_START;
while (i--)
writel(IC_RD, i2c->base + IC_DATA_CMD);
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");
intel_mid_i2c_hwinit(i2c);
return -ETIMEDOUT;
}
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 we cannot read the "raw" interrupt register
* -EINVAL if a transfer abort occurred
*
* 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 intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
int i, err;
if (length >= 256) {
dev_err(&adap->dev,
"I2C FIFO cannot support larger than 256 bytes\n");
return -EMSGSIZE;
}
INIT_COMPLETION(i2c->complete);
readl(i2c->base + IC_CLR_INTR);
writel(0x0050, i2c->base + IC_INTR_MASK);
i2c->status = STATUS_WRITE_START;
for (i = 0; i < length; i++)
writel((u16)(*(buf + i)), i2c->base + IC_DATA_CMD);
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");
intel_mid_i2c_hwinit(i2c);
return -ETIMEDOUT;
} else {
if (i2c->status == STATUS_WRITE_SUCCESS)
return 0;
else
return -EIO;
}
}
static int intel_mid_i2c_setup(struct i2c_adapter *adap, struct i2c_msg *pmsg)
{
struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
int err;
u32 reg;
u32 bit_mask;
u32 mode;
/* Disable device first */
err = intel_mid_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 = readl(i2c->base + IC_CON);
if ((reg & 0x06) != mode) {
dev_dbg(&adap->dev, "set mode %d\n", i2c->speed);
writel((reg & ~0x6) | mode, i2c->base + IC_CON);
}
reg = readl(i2c->base + IC_CON);
/* use 7-bit addressing */
if (pmsg->flags & I2C_M_TEN) {
if ((reg & ADDR_10BIT) != ADDR_10BIT) {
dev_dbg(&adap->dev, "set i2c 10 bit address mode\n");
writel(reg | ADDR_10BIT, i2c->base + IC_CON);
}
} else {
if ((reg & ADDR_10BIT) != 0x0) {
dev_dbg(&adap->dev, "set i2c 7 bit address mode\n");
writel(reg & ~ADDR_10BIT, i2c->base + IC_CON);
}
}
/* enable restart conditions */
reg = readl(i2c->base + IC_CON);
if ((reg & RESTART) != RESTART) {
dev_dbg(&adap->dev, "enable restart conditions\n");
writel(reg | RESTART, i2c->base + IC_CON);
}
/* enable master FSM */
reg = readl(i2c->base + IC_CON);
dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
writel(reg | MASTER_EN, i2c->base + IC_CON);
if ((reg & SLV_DIS) != SLV_DIS) {
dev_dbg(&adap->dev, "enable master FSM\n");
writel(reg | SLV_DIS, i2c->base + IC_CON);
dev_dbg(&adap->dev, "ic_con reg is 0x%x\n", reg);
}
/* use target address when initiating transfer */
reg = readl(i2c->base + IC_TAR);
bit_mask = IC_TAR_SPECIAL | IC_TAR_GC_OR_START;
if ((reg & bit_mask) != 0x0) {
dev_dbg(&adap->dev,
"WR: use target address when intiating transfer, i2c_tx_target\n");
writel(reg & ~bit_mask, i2c->base + IC_TAR);
}
/* 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);
writel(pmsg->addr | (pmsg->flags & I2C_M_TEN ? IC_TAR_10BIT_ADDR : 0),
i2c->base + IC_TAR);
/* Enable I2C controller */
writel(ENABLE, i2c->base + IC_ENABLE);
return 0;
}
/**
* intel_mid_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 transferred
* -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 intel_mid_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg *pmsg,
int num)
{
struct intel_mid_i2c_private *i2c = i2c_get_adapdata(adap);
int i, err = 0;
/* if number of messages equal 0*/
if (num == 0)
return 0;
pm_runtime_get(i2c->dev);
mutex_lock(&i2c->lock);
dev_dbg(&adap->dev, "intel_mid_i2c_xfer, process %d msg(s)\n", num);
dev_dbg(&adap->dev, "slave address is %x\n", pmsg->addr);
if (i2c->status != STATUS_IDLE) {
dev_err(&adap->dev, "Adapter %d in transfer/standby\n",
adap->nr);
mutex_unlock(&i2c->lock);
pm_runtime_put(i2c->dev);
return -1;
}
for (i = 1; i < num; i++) {
/* Message address equal? */
if (unlikely(intel_mid_i2c_address_neq(&pmsg[0], &pmsg[i]))) {
dev_err(&adap->dev, "Invalid address in msg[%d]\n", i);
mutex_unlock(&i2c->lock);
pm_runtime_put(i2c->dev);
return -EINVAL;
}
}
if (intel_mid_i2c_setup(adap, pmsg)) {
mutex_unlock(&i2c->lock);
pm_runtime_put(i2c->dev);
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)
break;
dev_dbg(&adap->dev, "msg[%d] transfer complete\n", i);
pmsg++; /* next message */
}
/* Mask interrupts */
writel(0x0000, i2c->base + IC_INTR_MASK);
/* Clear all interrupts */
readl(i2c->base + IC_CLR_INTR);
i2c->status = STATUS_IDLE;
mutex_unlock(&i2c->lock);
pm_runtime_put(i2c->dev);
return err;
}
static int intel_mid_i2c_runtime_suspend(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct intel_mid_i2c_private *i2c = pci_get_drvdata(pdev);
struct i2c_adapter *adap = to_i2c_adapter(dev);
int err;
if (i2c->status != STATUS_IDLE)
return -1;
intel_mid_i2c_disable(adap);
err = pci_save_state(pdev);
if (err) {
dev_err(dev, "pci_save_state failed\n");
return err;
}
err = pci_set_power_state(pdev, PCI_D3hot);
if (err) {
dev_err(dev, "pci_set_power_state failed\n");
return err;
}
i2c->status = STATUS_STANDBY;
return 0;
}
static int intel_mid_i2c_runtime_resume(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct intel_mid_i2c_private *i2c = pci_get_drvdata(pdev);
int err;
if (i2c->status != STATUS_STANDBY)
return 0;
pci_set_power_state(pdev, PCI_D0);
pci_restore_state(pdev);
err = pci_enable_device(pdev);
if (err) {
dev_err(dev, "pci_enable_device failed\n");
return err;
}
i2c->status = STATUS_IDLE;
intel_mid_i2c_hwinit(i2c);
return err;
}
static void i2c_isr_read(struct intel_mid_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 = readl(i2c->base + IC_RXFLR);
for (; len > 0 && rx_num > 0; len--, rx_num--)
*buf++ = readl(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 intel_mid_i2c_isr(int this_irq, void *dev)
{
struct intel_mid_i2c_private *i2c = dev;
u32 stat = readl(i2c->base + IC_INTR_STAT);
if (!stat)
return IRQ_NONE;
dev_dbg(&i2c->adap.dev, "%s, stat = 0x%x\n", __func__, stat);
stat &= 0x54;
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 = readl(i2c->base + IC_TX_ABRT_SOURCE);
readl(i2c->base + IC_CLR_INTR);
if (stat & TX_ABRT) {
intel_mid_i2c_abort(i2c);
goto exit;
}
if (stat & RX_FULL) {
i2c_isr_read(i2c);
goto exit;
}
if (stat & TX_EMPTY) {
if (readl(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) {
/* Clear all interrupts */
readl(i2c->base + IC_CLR_INTR);
/* Mask interrupts */
writel(0, i2c->base + IC_INTR_MASK);
complete(&i2c->complete);
}
err:
return IRQ_HANDLED;
}
static struct i2c_algorithm intel_mid_i2c_algorithm = {
.master_xfer = intel_mid_i2c_xfer,
.functionality = intel_mid_i2c_func,
};
static const struct dev_pm_ops intel_mid_i2c_pm_ops = {
.runtime_suspend = intel_mid_i2c_runtime_suspend,
.runtime_resume = intel_mid_i2c_runtime_resume,
};
/**
* intel_mid_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 intel_mid_i2c_private
* 5. Call intel_mid_i2c_hwinit() for hardware initialization
* 6. Register I2C adapter in i2c-core
*/
static int intel_mid_i2c_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
struct intel_mid_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, intel_mid_i2c_private */
mrst = kzalloc(sizeof(struct intel_mid_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),
"Intel MID I2C at %lx", start);
mrst->adap.owner = THIS_MODULE;
mrst->adap.algo = &intel_mid_i2c_algorithm;
mrst->adap.dev.parent = &dev->dev;
mrst->dev = &dev->dev;
mrst->base = base;
mrst->speed = STANDARD;
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 = intel_mid_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);
/* Clear all interrupts */
readl(mrst->base + IC_CLR_INTR);
writel(0x0000, mrst->base + IC_INTR_MASK);
err = request_irq(dev->irq, intel_mid_i2c_isr, IRQF_SHARED,
mrst->adap.name, mrst);
if (err) {
dev_err(&dev->dev, "Failed to request IRQ for I2C controller: "
"%s", mrst->adap.name);
goto fail2;
}
/* 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);
pm_runtime_enable(&dev->dev);
return 0;
fail3:
free_irq(dev->irq, mrst);
fail2:
kfree(mrst);
fail1:
iounmap(base);
fail0:
pci_release_region(dev, 0);
exit:
return err;
}
static void intel_mid_i2c_remove(struct pci_dev *dev)
{
struct intel_mid_i2c_private *mrst = pci_get_drvdata(dev);
intel_mid_i2c_disable(&mrst->adap);
i2c_del_adapter(&mrst->adap);
free_irq(dev->irq, mrst);
iounmap(mrst->base);
kfree(mrst);
pci_release_region(dev, 0);
}
static DEFINE_PCI_DEVICE_TABLE(intel_mid_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, intel_mid_i2c_ids);
static struct pci_driver intel_mid_i2c_driver = {
.name = DRIVER_NAME,
.id_table = intel_mid_i2c_ids,
.probe = intel_mid_i2c_probe,
.remove = intel_mid_i2c_remove,
};
module_pci_driver(intel_mid_i2c_driver);
MODULE_AUTHOR("Ba Zheng <zheng.ba@intel.com>");
MODULE_DESCRIPTION("I2C driver for Moorestown Platform");
MODULE_LICENSE("GPL");
MODULE_VERSION(VERSION);