diff options
| -rw-r--r-- | drivers/i2c/busses/i2c-gpio.c | 102 |
1 files changed, 39 insertions, 63 deletions
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c index b4664037eded..97b9c29e9429 100644 --- a/drivers/i2c/busses/i2c-gpio.c +++ b/drivers/i2c/busses/i2c-gpio.c @@ -25,23 +25,6 @@ struct i2c_gpio_private_data { struct i2c_gpio_platform_data pdata; }; -/* Toggle SDA by changing the direction of the pin */ -static void i2c_gpio_setsda_dir(void *data, int state) -{ - struct i2c_gpio_private_data *priv = data; - - /* - * This is a way of saying "do not drive - * me actively high" which means emulating open drain. - * The right way to do this is for gpiolib to - * handle this, by the function below. - */ - if (state) - gpiod_direction_input(priv->sda); - else - gpiod_direction_output(priv->sda, 0); -} - /* * Toggle SDA by changing the output value of the pin. This is only * valid for pins configured as open drain (i.e. setting the value @@ -54,17 +37,6 @@ static void i2c_gpio_setsda_val(void *data, int state) gpiod_set_value(priv->sda, state); } -/* Toggle SCL by changing the direction of the pin. */ -static void i2c_gpio_setscl_dir(void *data, int state) -{ - struct i2c_gpio_private_data *priv = data; - - if (state) - gpiod_direction_input(priv->scl); - else - gpiod_direction_output(priv->scl, 0); -} - /* * Toggle SCL by changing the output value of the pin. This is used * for pins that are configured as open drain and for output-only @@ -116,30 +88,13 @@ static int i2c_gpio_probe(struct platform_device *pdev) struct i2c_gpio_platform_data *pdata; struct i2c_algo_bit_data *bit_data; struct i2c_adapter *adap; + enum gpiod_flags gflags; int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; - /* First get the GPIO pins; if it fails, we'll defer the probe. */ - priv->sda = devm_gpiod_get_index(&pdev->dev, NULL, 0, GPIOD_OUT_HIGH); - if (IS_ERR(priv->sda)) { - ret = PTR_ERR(priv->sda); - /* FIXME: hack in the old code, is this really necessary? */ - if (ret == -EINVAL) - ret = -EPROBE_DEFER; - return ret; - } - priv->scl = devm_gpiod_get_index(&pdev->dev, NULL, 1, GPIOD_OUT_LOW); - if (IS_ERR(priv->scl)) { - ret = PTR_ERR(priv->scl); - /* FIXME: hack in the old code, is this really necessary? */ - if (ret == -EINVAL) - ret = -EPROBE_DEFER; - return ret; - } - adap = &priv->adap; bit_data = &priv->bit_data; pdata = &priv->pdata; @@ -157,27 +112,48 @@ static int i2c_gpio_probe(struct platform_device *pdev) } /* - * FIXME: this is a hack emulating the open drain emulation - * that gpiolib can already do for us. Make all clients properly - * flag their lines as open drain and get rid of this property - * and the special callback. + * First get the GPIO pins; if it fails, we'll defer the probe. + * If the SDA line is marked from platform data or device tree as + * "open drain" it means something outside of our control is making + * this line being handled as open drain, and we should just handle + * it as any other output. Else we enforce open drain as this is + * required for an I2C bus. */ - if (pdata->sda_is_open_drain) { - gpiod_direction_output(priv->sda, 1); - bit_data->setsda = i2c_gpio_setsda_val; - } else { - gpiod_direction_input(priv->sda); - bit_data->setsda = i2c_gpio_setsda_dir; + if (pdata->sda_is_open_drain) + gflags = GPIOD_OUT_HIGH; + else + gflags = GPIOD_OUT_HIGH_OPEN_DRAIN; + priv->sda = devm_gpiod_get_index(&pdev->dev, NULL, 0, gflags); + if (IS_ERR(priv->sda)) { + ret = PTR_ERR(priv->sda); + /* FIXME: hack in the old code, is this really necessary? */ + if (ret == -EINVAL) + ret = -EPROBE_DEFER; + return ret; } - - if (pdata->scl_is_open_drain || pdata->scl_is_output_only) { - gpiod_direction_output(priv->scl, 1); - bit_data->setscl = i2c_gpio_setscl_val; - } else { - gpiod_direction_input(priv->scl); - bit_data->setscl = i2c_gpio_setscl_dir; + /* + * If the SCL line is marked from platform data or device tree as + * "open drain" it means something outside of our control is making + * this line being handled as open drain, and we should just handle + * it as any other output. Else we enforce open drain as this is + * required for an I2C bus. + */ + if (pdata->scl_is_open_drain) + gflags = GPIOD_OUT_LOW; + else + gflags = GPIOD_OUT_LOW_OPEN_DRAIN; + priv->scl = devm_gpiod_get_index(&pdev->dev, NULL, 1, gflags); + if (IS_ERR(priv->scl)) { + ret = PTR_ERR(priv->scl); + /* FIXME: hack in the old code, is this really necessary? */ + if (ret == -EINVAL) + ret = -EPROBE_DEFER; + return ret; } + bit_data->setsda = i2c_gpio_setsda_val; + bit_data->setscl = i2c_gpio_setscl_val; + if (!pdata->scl_is_output_only) bit_data->getscl = i2c_gpio_getscl; bit_data->getsda = i2c_gpio_getsda; |