In the process of moving over from static board files to the device tree, reset pins of peripheral reset pins should be handled by their corresponding drivers.
Add a reset-gpio DT property to the cs4270 driver, and de-assert it before probing the chip. The logic could be augmented some day to re-assert it when codec is put to suspend.
Signed-off-by: Daniel Mack zonque@gmail.com Cc: Timur Tabi timur@freescale.com --- v2: cleanups as requested by Timur v3: return error code in case devm_gpio_request_one() fails
Documentation/devicetree/bindings/sound/cs4270.txt | 5 +++++ sound/soc/codecs/cs4270.c | 17 +++++++++++++++++ 2 files changed, 22 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/cs4270.txt b/Documentation/devicetree/bindings/sound/cs4270.txt index 7f0bfd8..6b222f9 100644 --- a/Documentation/devicetree/bindings/sound/cs4270.txt +++ b/Documentation/devicetree/bindings/sound/cs4270.txt @@ -8,6 +8,11 @@ Required properties:
- reg : the I2C address of the device for I2C
+Optional properties: + + - reset-gpio : a GPIO spec for the reset pin. If specified, it will be + deasserted before communication to the codec starts. + Example:
codec: cs4270@48 { diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c index 4b71b01..fd11bb6 100644 --- a/sound/soc/codecs/cs4270.c +++ b/sound/soc/codecs/cs4270.c @@ -30,6 +30,7 @@ #include <linux/delay.h> #include <linux/regulator/consumer.h> #include <linux/of_device.h> +#include <linux/of_gpio.h>
/* * The codec isn't really big-endian or little-endian, since the I2S @@ -660,9 +661,25 @@ MODULE_DEVICE_TABLE(of, cs4270_of_match); static int cs4270_i2c_probe(struct i2c_client *i2c_client, const struct i2c_device_id *id) { + struct device_node *np = i2c_client->dev.of_node; struct cs4270_private *cs4270; int ret;
+ /* See if we have a way to bring the codec out of reset */ + if (np) { + enum of_gpio_flags flags; + int gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags); + + if (gpio_is_valid(gpio)) { + ret = devm_gpio_request_one(&i2c_client->dev, gpio, + flags & OF_GPIO_ACTIVE_LOW ? + GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH, + "cs4270 reset"); + if (ret < 0) + return ret; + } + } + /* Verify that we have a CS4270 */
ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);