From f237cf1914e24ebba88670ecc36e8209c888c9a2 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Tue, 15 Nov 2022 10:55:17 +0100 Subject: 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 --- drivers/iio/addac/ad74413r.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/iio') diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c index 29b3a5775f23..61030053cbea 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), -- cgit v1.2.3