[PATCH 3/5] iio: adc: ti-ads1262: Add GPIO controller support

[Kurt Borja]

Add support for the GPIO controller capability found in both TI ADS1262
and ADS1263 ADCs.

Eight analog input pins can be programmed as GPIO. This configuration
does not prevent the pins from being used as analog inputs at the same
time, so no considerations were taken in that regard.

Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
---
 drivers/iio/adc/ti-ads1262.c | 149 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)

diff --git a/drivers/iio/adc/ti-ads1262.c b/drivers/iio/adc/ti-ads1262.c
index fd1911cf65ac..6d5f22836ad8 100644
--- a/drivers/iio/adc/ti-ads1262.c
+++ b/drivers/iio/adc/ti-ads1262.c
@@ -17,6 +17,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
 #include <linux/interrupt.h>
 #include <linux/lockdep.h>
 #include <linux/math.h>
@@ -314,6 +315,10 @@ static const int ads1262_pga_gain_avail[] = {
 	1, 2, 4, 8, 16, 32
 };
 
+static const char * const ads1262_gpio_names[] = {
+	"AIN3", "AIN4", "AIN5", "AIN6", "AIN7", "AIN8", "AIN9", "AINCOM"
+};
+
 static int ads1262_dev_power_on(struct ads1262 *st)
 {
 	int ret;
@@ -1050,6 +1055,146 @@ static irqreturn_t ads1262_trigger_handler(int irq, void *p)
 	return IRQ_HANDLED;
 }
 
+static int ads1262_gpiochip_request(struct gpio_chip *gc, unsigned int offset)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	struct device *dev = &st->spi->dev;
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(st->regmap, ADS1262_GPIOCON_REG,
+				  BIT(offset), BIT(offset));
+}
+
+static void ads1262_gpiochip_free(struct gpio_chip *gc, unsigned int offset)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	struct device *dev = &st->spi->dev;
+
+	regmap_update_bits(st->regmap, ADS1262_GPIOCON_REG, BIT(offset), 0);
+	pm_runtime_put_autosuspend(dev);
+}
+
+static int ads1262_gpiochip_get_direction(struct gpio_chip *gc,
+					  unsigned int offset)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, ADS1262_GPIODIR_REG, &val);
+	if (ret)
+		return ret;
+
+	return val & BIT(offset);
+}
+
+static int ads1262_gpiochip_direction_input(struct gpio_chip *gc,
+					    unsigned int offset)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+
+	return regmap_update_bits(st->regmap, ADS1262_GPIODIR_REG,
+				  BIT(offset), 1);
+}
+
+static int ads1262_gpiochip_direction_output(struct gpio_chip *gc,
+					     unsigned int offset, int value)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	int ret;
+
+	ret = regmap_update_bits(st->regmap, ADS1262_GPIODIR_REG,
+				 BIT(offset), 0);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(st->regmap, ADS1262_GPIODAT_REG,
+				  BIT(offset), value ? BIT(offset) : 0);
+}
+
+static int ads1262_gpiochip_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, ADS1262_GPIODAT_REG, &val);
+	if (ret)
+		return ret;
+
+	return val & BIT(offset);
+}
+
+static int ads1262_gpiochip_get_multiple(struct gpio_chip *gc,
+					 unsigned long *mask,
+					 unsigned long *bits)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, ADS1262_GPIODAT_REG, &val);
+	if (ret)
+		return ret;
+
+	return val & *mask;
+}
+
+static int ads1262_gpiochip_set(struct gpio_chip *gc, unsigned int offset,
+				int value)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+
+	return regmap_update_bits(st->regmap, ADS1262_GPIODAT_REG,
+				  BIT(offset), value ? BIT(offset) : 0);
+}
+
+static int ads1262_gpiochip_set_multiple(struct gpio_chip *gc,
+					 unsigned long *mask,
+					 unsigned long *bits)
+{
+	struct ads1262 *st = gpiochip_get_data(gc);
+
+	return regmap_update_bits(st->regmap, ADS1262_GPIODAT_REG, *mask,
+				  *bits);
+}
+
+static int ads1262_gpiochip_setup(struct ads1262 *st, const char *name)
+{
+	struct device *dev = &st->spi->dev;
+	struct gpio_chip *gc;
+
+	if (!device_property_present(dev, "gpio-controller"))
+		return 0;
+
+	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+	if (!gc)
+		return -ENOMEM;
+
+	gc->owner = THIS_MODULE;
+	gc->label = name;
+	gc->base = -1;
+	gc->ngpio = ARRAY_SIZE(ads1262_gpio_names);
+	gc->parent = dev;
+	gc->can_sleep = true;
+	gc->request = ads1262_gpiochip_request;
+	gc->free = ads1262_gpiochip_free;
+	gc->get_direction = ads1262_gpiochip_get_direction;
+	gc->direction_input = ads1262_gpiochip_direction_input;
+	gc->direction_output = ads1262_gpiochip_direction_output;
+	gc->get = ads1262_gpiochip_get;
+	gc->get_multiple = ads1262_gpiochip_get_multiple;
+	gc->set = ads1262_gpiochip_set;
+	gc->set_multiple = ads1262_gpiochip_set_multiple;
+	gc->names = ads1262_gpio_names;
+
+	return devm_gpiochip_add_data(dev, gc, st);
+}
+
 static int ads1262_parse_channel_data(struct ads1262 *st,
 				      struct ads1262_channel *chan_data,
 				      struct fwnode_handle *node)
@@ -1750,6 +1895,10 @@ static int ads1262_spi_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	ret = ads1262_gpiochip_setup(st, name);
+	if (ret)
+		return ret;
+
 	return devm_iio_device_register(dev, indio_dev);
 }
 

-- 
2.54.0