diff options
| -rw-r--r-- | drivers/i2c/busses/i2c-davinci.c | 77 |
1 files changed, 36 insertions, 41 deletions
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index 120a4ef36ef5..54819fb4f82e 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -129,43 +129,6 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg) return readw_relaxed(i2c_dev->base + reg); } -/* Generate a pulse on the i2c clock pin. */ -static void davinci_i2c_clock_pulse(unsigned int scl_pin) -{ - u16 i; - - if (scl_pin) { - /* Send high and low on the SCL line */ - for (i = 0; i < 9; i++) { - gpio_set_value(scl_pin, 0); - udelay(20); - gpio_set_value(scl_pin, 1); - udelay(20); - } - } -} - -/* This routine does i2c bus recovery as specified in the - * i2c protocol Rev. 03 section 3.16 titled "Bus clear" - */ -static void davinci_i2c_recover_bus(struct davinci_i2c_dev *dev) -{ - u32 flag = 0; - struct davinci_i2c_platform_data *pdata = dev->pdata; - - dev_err(dev->dev, "initiating i2c bus recovery\n"); - /* Send NACK to the slave */ - flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - flag |= DAVINCI_I2C_MDR_NACK; - /* write the data into mode register */ - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); - davinci_i2c_clock_pulse(pdata->scl_pin); - /* Send STOP */ - flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG); - flag |= DAVINCI_I2C_MDR_STP; - davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); -} - static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev, int val) { @@ -263,6 +226,34 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev) } /* + * This routine does i2c bus recovery by using i2c_generic_gpio_recovery + * which is provided by I2C Bus recovery infrastructure. + */ +static void davinci_i2c_prepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + /* Disable interrupts */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, 0); + + /* put I2C into reset */ + davinci_i2c_reset_ctrl(dev, 0); +} + +static void davinci_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + struct davinci_i2c_dev *dev = i2c_get_adapdata(adap); + + i2c_davinci_init(dev); +} + +static struct i2c_bus_recovery_info davinci_i2c_gpio_recovery_info = { + .recover_bus = i2c_generic_gpio_recovery, + .prepare_recovery = davinci_i2c_prepare_recovery, + .unprepare_recovery = davinci_i2c_unprepare_recovery, +}; + +/* * Waiting for bus not busy */ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev, @@ -282,8 +273,7 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev, return -ETIMEDOUT; } else { to_cnt = 0; - davinci_i2c_recover_bus(dev); - i2c_davinci_init(dev); + i2c_recover_bus(&dev->adapter); } } if (allow_sleep) @@ -372,8 +362,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop) dev->adapter.timeout); if (!time_left) { dev_err(dev->dev, "controller timed out\n"); - davinci_i2c_recover_bus(dev); - i2c_davinci_init(dev); + i2c_recover_bus(adap); dev->buf_len = 0; return -ETIMEDOUT; } @@ -712,6 +701,12 @@ static int davinci_i2c_probe(struct platform_device *pdev) adap->timeout = DAVINCI_I2C_TIMEOUT; adap->dev.of_node = pdev->dev.of_node; + if (dev->pdata->scl_pin) { + adap->bus_recovery_info = &davinci_i2c_gpio_recovery_info; + adap->bus_recovery_info->scl_gpio = dev->pdata->scl_pin; + adap->bus_recovery_info->sda_gpio = dev->pdata->sda_pin; + } + adap->nr = pdev->id; r = i2c_add_numbered_adapter(adap); if (r) { |