lkml.org 
[lkml]   [2014]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v3 4/5] i2c: davinci: use bus recovery infrastructure
    Date
    This patch converts Davinci I2C driver to use I2C bus recovery
    infrastructure, introduced by commit 5f9296ba21b3 ("i2c: Add
    bus recovery infrastructure").

    The i2c_bus_recovery_info is configured for Davinci I2C adapter
    only in case scl_pin is provided in platform data.

    As the controller must be held in reset while doing so, the
    recovery routine must re-init the controller. Since this was already
    being done after each call to i2c_recover_bus, move those calls into
    the recovery_prepare/unprepare routines and as well.

    CC: Sekhar Nori <nsekhar@ti.com>
    CC: Kevin Hilman <khilman@deeprootsystems.com>
    CC: Santosh Shilimkar <ssantosh@kernel.org>
    CC: Murali Karicheri <m-karicheri2@ti.com>
    Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
    ---
    drivers/i2c/busses/i2c-davinci.c | 77 +++++++++++++++++++---------------------
    1 file changed, 36 insertions(+), 41 deletions(-)

    diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
    index 17e1203..00aed63 100644
    --- a/drivers/i2c/busses/i2c-davinci.c
    +++ b/drivers/i2c/busses/i2c-davinci.c
    @@ -133,43 +133,6 @@ 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)
    {
    @@ -267,6 +230,34 @@ 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,
    @@ -286,8 +277,7 @@ 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)
    @@ -376,8 +366,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
    dev->adapter.timeout);
    if (r == 0) {
    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;
    }
    @@ -721,6 +710,12 @@ 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) {
    --
    1.9.1


    \
     
     \ /
      Last update: 2014-12-01 17:01    [W:5.849 / U:0.284 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site