From: Rasmus Villemoes Date: Tue, 15 Nov 2022 09:55:17 +0000 (+0100) Subject: iio: addac: ad74413r: add support for reset-gpio X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f237cf1914e24ebba88670ecc36e8209c888c9a2;p=linux.git iio: addac: ad74413r: add support for reset-gpio We have a board where the reset pin of the ad74412 is connected to a gpio, but also pulled low (i.e., asserted) by default. Hence to get the chip out of reset, the driver needs to know about that gpio and deassert the reset signal before attempting to communicate with the chip. When a reset-gpio is given in device tree, use that instead of the software reset. According to the data sheet, the two methods are functionally equivalent. Signed-off-by: Rasmus Villemoes Link: https://lore.kernel.org/r/20221115095517.1008632-4-linux@rasmusvillemoes.dk Signed-off-by: Jonathan Cameron --- diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c index 29b3a5775f236..61030053cbeaa 100644 --- a/drivers/iio/addac/ad74413r.c +++ b/drivers/iio/addac/ad74413r.c @@ -71,6 +71,7 @@ struct ad74413r_state { struct regmap *regmap; struct device *dev; struct iio_trigger *trig; + struct gpio_desc *reset_gpio; size_t adc_active_channels; struct spi_message adc_samples_msg; @@ -393,6 +394,13 @@ static int ad74413r_reset(struct ad74413r_state *st) { int ret; + if (st->reset_gpio) { + gpiod_set_value_cansleep(st->reset_gpio, 1); + fsleep(50); + gpiod_set_value_cansleep(st->reset_gpio, 0); + return 0; + } + ret = regmap_write(st->regmap, AD74413R_REG_CMD_KEY, AD74413R_CMD_KEY_RESET1); if (ret) @@ -1322,6 +1330,10 @@ static int ad74413r_probe(struct spi_device *spi) if (IS_ERR(st->regmap)) return PTR_ERR(st->regmap); + st->reset_gpio = devm_gpiod_get_optional(st->dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(st->reset_gpio)) + return PTR_ERR(st->reset_gpio); + st->refin_reg = devm_regulator_get(st->dev, "refin"); if (IS_ERR(st->refin_reg)) return dev_err_probe(st->dev, PTR_ERR(st->refin_reg),