From c1e289a0364b4fffb91f3bbd278d623e14922d1f Mon Sep 17 00:00:00 2001 From: Marcelo Schmitt Date: Mon, 7 Jul 2025 10:53:48 -0300 Subject: [PATCH] iio: adc: ad4170-4: Add GPIO controller support The AD4170-4 has four multifunctional pins that can be used as GPIOs. The GPIO functionality can be accessed when the AD4170-4 chip is not busy performing continuous data capture or handling any other register read/write request. Also, the AD4170-4 does not provide any interrupt based on GPIO pin states so AD4170-4 GPIOs can't be used as interrupt sources. Implement gpio_chip callbacks to make AD4170-4 GPIO pins controllable through the gpiochip interface. Acked-by: Bartosz Golaszewski Reviewed-by: Linus Walleij Signed-off-by: Marcelo Schmitt Link: https://patch.msgid.link/e031189d4b7e20cf02dd13220ab1ddf4798760c2.1751895245.git.marcelo.schmitt@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/adc/Kconfig | 1 + drivers/iio/adc/ad4170-4.c | 224 ++++++++++++++++++++++++++++++++++++- 2 files changed, 224 insertions(+), 1 deletion(-) diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 36e506e8d8f1..d43edc7b0c0f 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -92,6 +92,7 @@ config AD4170_4 select IIO_BUFFER select IIO_TRIGGERED_BUFFER depends on COMMON_CLK + depends on GPIOLIB help Say yes here to build support for Analog Devices AD4170-4 SPI analog to digital converters (ADC). diff --git a/drivers/iio/adc/ad4170-4.c b/drivers/iio/adc/ad4170-4.c index 32e52d24656a..3153680c0a30 100644 --- a/drivers/iio/adc/ad4170-4.c +++ b/drivers/iio/adc/ad4170-4.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -68,6 +69,9 @@ #define AD4170_FILTER_FS_REG(x) (0xC7 + 14 * (x)) #define AD4170_OFFSET_REG(x) (0xCA + 14 * (x)) #define AD4170_GAIN_REG(x) (0xCD + 14 * (x)) +#define AD4170_GPIO_MODE_REG 0x191 +#define AD4170_GPIO_OUTPUT_REG 0x193 +#define AD4170_GPIO_INPUT_REG 0x195 #define AD4170_ADC_CTRL_CONT_READ_EXIT_REG 0x200 /* virtual reg */ #define AD4170_REG_READ_MASK BIT(14) @@ -106,6 +110,12 @@ /* AD4170_FILTER_REG */ #define AD4170_FILTER_FILTER_TYPE_MSK GENMASK(3, 0) +/* AD4170_GPIO_MODE_REG */ +#define AD4170_GPIO_MODE_GPIO0_MSK GENMASK(1, 0) +#define AD4170_GPIO_MODE_GPIO1_MSK GENMASK(3, 2) +#define AD4170_GPIO_MODE_GPIO2_MSK GENMASK(5, 4) +#define AD4170_GPIO_MODE_GPIO3_MSK GENMASK(7, 6) + /* AD4170 register constants */ /* AD4170_CLOCK_CTRL_REG constants */ @@ -146,9 +156,14 @@ #define AD4170_FILTER_FILTER_TYPE_SINC5 0x4 #define AD4170_FILTER_FILTER_TYPE_SINC3 0x6 +/* AD4170_GPIO_MODE_REG constants */ +#define AD4170_GPIO_MODE_GPIO_INPUT 1 +#define AD4170_GPIO_MODE_GPIO_OUTPUT 2 + /* Device properties and auxiliary constants */ #define AD4170_NUM_ANALOG_PINS 9 +#define AD4170_NUM_GPIO_PINS 4 #define AD4170_MAX_ADC_CHANNELS 16 #define AD4170_MAX_IIO_CHANNELS (AD4170_MAX_ADC_CHANNELS + 1) #define AD4170_MAX_ANALOG_PINS 8 @@ -177,6 +192,9 @@ #define AD4170_ADC_CTRL_CONT_READ_EXIT 0xA5 +/* GPIO pin functions */ +#define AD4170_GPIO_UNASSIGNED 0x00 + static const unsigned int ad4170_reg_size[] = { [AD4170_CONFIG_A_REG] = 1, [AD4170_DATA_24B_REG] = 3, @@ -214,6 +232,9 @@ static const unsigned int ad4170_reg_size[] = { [AD4170_OFFSET_REG(5) ... AD4170_GAIN_REG(5)] = 3, [AD4170_OFFSET_REG(6) ... AD4170_GAIN_REG(6)] = 3, [AD4170_OFFSET_REG(7) ... AD4170_GAIN_REG(7)] = 3, + [AD4170_GPIO_MODE_REG] = 2, + [AD4170_GPIO_OUTPUT_REG] = 2, + [AD4170_GPIO_INPUT_REG] = 2, [AD4170_ADC_CTRL_CONT_READ_EXIT_REG] = 0, }; @@ -365,6 +386,8 @@ struct ad4170_state { struct clk_hw int_clk_hw; unsigned int clock_ctrl; unsigned int pins_fn[AD4170_NUM_ANALOG_PINS]; + int gpio_fn[AD4170_NUM_GPIO_PINS]; + struct gpio_chip gpiochip; /* * DMA (thus cache coherency maintenance) requires the transfer buffers * to live in their own cache lines. @@ -1475,6 +1498,194 @@ static int ad4170_soft_reset(struct ad4170_state *st) return 0; } +static int ad4170_gpio_get(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int val; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val); + if (ret) + goto err_release; + + /* + * If the GPIO is configured as an input, read the current value from + * AD4170_GPIO_INPUT_REG. Otherwise, read the input value from + * AD4170_GPIO_OUTPUT_REG. + */ + if (val & BIT(offset * 2)) + ret = regmap_read(st->regmap, AD4170_GPIO_INPUT_REG, &val); + else + ret = regmap_read(st->regmap, AD4170_GPIO_OUTPUT_REG, &val); + if (ret) + goto err_release; + + ret = !!(val & BIT(offset)); +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_assign_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, + BIT(offset), !!value); + + iio_device_release_direct(indio_dev); + return ret; +} + +static int ad4170_gpio_get_direction(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned int val; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + ret = regmap_read(st->regmap, AD4170_GPIO_MODE_REG, &val); + if (ret) + goto err_release; + + if (val & BIT(offset * 2 + 1)) + ret = GPIO_LINE_DIRECTION_OUT; + else + ret = GPIO_LINE_DIRECTION_IN; + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_direction_input(struct gpio_chip *gc, unsigned int offset) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned long gpio_mask; + int ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + switch (offset) { + case 0: + gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK; + break; + case 1: + gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK; + break; + case 2: + gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK; + break; + case 3: + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK; + break; + default: + ret = -EINVAL; + goto err_release; + } + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + AD4170_GPIO_MODE_GPIO_INPUT << (2 * offset)); + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_direction_output(struct gpio_chip *gc, + unsigned int offset, int value) +{ + struct iio_dev *indio_dev = gpiochip_get_data(gc); + struct ad4170_state *st = iio_priv(indio_dev); + unsigned long gpio_mask; + int ret; + + ret = ad4170_gpio_set(gc, offset, value); + if (ret) + return ret; + + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; + + switch (offset) { + case 0: + gpio_mask = AD4170_GPIO_MODE_GPIO0_MSK; + break; + case 1: + gpio_mask = AD4170_GPIO_MODE_GPIO1_MSK; + break; + case 2: + gpio_mask = AD4170_GPIO_MODE_GPIO2_MSK; + break; + case 3: + gpio_mask = AD4170_GPIO_MODE_GPIO3_MSK; + break; + default: + ret = -EINVAL; + goto err_release; + } + ret = regmap_update_bits(st->regmap, AD4170_GPIO_MODE_REG, gpio_mask, + AD4170_GPIO_MODE_GPIO_OUTPUT << (2 * offset)); + +err_release: + iio_device_release_direct(indio_dev); + + return ret; +} + +static int ad4170_gpio_init_valid_mask(struct gpio_chip *gc, + unsigned long *valid_mask, + unsigned int ngpios) +{ + struct ad4170_state *st = gpiochip_get_data(gc); + unsigned int i; + + /* Only expose GPIOs that were not assigned any other function. */ + for (i = 0; i < ngpios; i++) { + bool valid = st->gpio_fn[i] == AD4170_GPIO_UNASSIGNED; + + __assign_bit(i, valid_mask, valid); + } + + return 0; +} + +static int ad4170_gpio_init(struct iio_dev *indio_dev) +{ + struct ad4170_state *st = iio_priv(indio_dev); + + st->gpiochip.label = "ad4170_gpios"; + st->gpiochip.base = -1; + st->gpiochip.ngpio = AD4170_NUM_GPIO_PINS; + st->gpiochip.parent = &st->spi->dev; + st->gpiochip.can_sleep = true; + st->gpiochip.init_valid_mask = ad4170_gpio_init_valid_mask; + st->gpiochip.get_direction = ad4170_gpio_get_direction; + st->gpiochip.direction_input = ad4170_gpio_direction_input; + st->gpiochip.direction_output = ad4170_gpio_direction_output; + st->gpiochip.get = ad4170_gpio_get; + st->gpiochip.set_rv = ad4170_gpio_set; + st->gpiochip.owner = THIS_MODULE; + + return devm_gpiochip_add_data(&st->spi->dev, &st->gpiochip, indio_dev); +} + static int ad4170_parse_reference(struct ad4170_state *st, struct fwnode_handle *child, struct ad4170_setup *setup) @@ -1818,7 +2029,18 @@ static int ad4170_parse_firmware(struct iio_dev *indio_dev) if (ret) return ret; - return ad4170_parse_channels(indio_dev); + ret = ad4170_parse_channels(indio_dev); + if (ret) + return ret; + + /* Only create a GPIO chip if flagged for it */ + if (device_property_read_bool(dev, "gpio-controller")) { + ret = ad4170_gpio_init(indio_dev); + if (ret) + return ret; + } + + return 0; } static int ad4170_initial_config(struct iio_dev *indio_dev) -- 2.47.2