From: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
The AD7768-1 has the ability to control other local hardware (such as gain
stages),to power down other blocks in the signal chain, or read local
status signals over the SPI interface.
This change exports the AD7768-1's four gpios and makes them accessible
at an upper layer.
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
---
drivers/iio/adc/ad7768-1.c | 121 +++++++++++++++++++++++++++++++++++++
1 file changed, 121 insertions(+)
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 675af9ea856d..9741a6d47942 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -10,6 +10,8 @@
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -77,6 +79,19 @@
#define AD7768_CONV_MODE_MSK GENMASK(2, 0)
#define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x)
+/* AD7768_REG_GPIO_CONTROL */
+#define AD7768_GPIO_CONTROL_MSK GENMASK(3, 0)
+#define AD7768_GPIO_UNIVERSAL_EN BIT(7)
+
+/* AD7768_REG_GPIO_WRITE */
+#define AD7768_GPIO_WRITE_MSK GENMASK(3, 0)
+
+/* AD7768_REG_GPIO_READ */
+#define AD7768_GPIO_READ_MSK GENMASK(3, 0)
+
+#define AD7768_GPIO_INPUT(x) 0x00
+#define AD7768_GPIO_OUTPUT(x) BIT(x)
+
#define AD7768_RD_FLAG_MSK(x) (BIT(6) | ((x) & 0x3F))
#define AD7768_WR_FLAG_MSK(x) ((x) & 0x3F)
@@ -190,6 +205,8 @@ struct ad7768_state {
struct regulator *vref;
struct mutex lock;
struct clk *mclk;
+ struct gpio_chip gpiochip;
+ unsigned int gpio_avail_map;
unsigned int mclk_freq;
unsigned int samp_freq;
unsigned int common_mode_voltage;
@@ -338,6 +355,106 @@ static int ad7768_set_dig_fil(struct ad7768_state *st,
return 0;
}
+static int ad7768_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ad7768_state *st = gpiochip_get_data(chip);
+
+ guard(mutex)(&st->lock);
+ return ad7768_spi_reg_write_masked(st,
+ AD7768_REG_GPIO_CONTROL,
+ BIT(offset),
+ AD7768_GPIO_INPUT(offset));
+}
+
+static int ad7768_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct ad7768_state *st = gpiochip_get_data(chip);
+
+ guard(mutex)(&st->lock);
+ return ad7768_spi_reg_write_masked(st,
+ AD7768_REG_GPIO_CONTROL,
+ BIT(offset),
+ AD7768_GPIO_OUTPUT(offset));
+}
+
+static int ad7768_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ad7768_state *st = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+ ret = ad7768_spi_reg_read(st, AD7768_REG_GPIO_CONTROL, &val, 1);
+ if (ret < 0)
+ return ret;
+
+ if (val & BIT(offset))
+ ret = ad7768_spi_reg_read(st, AD7768_REG_GPIO_WRITE, &val, 1);
+ else
+ ret = ad7768_spi_reg_read(st, AD7768_REG_GPIO_READ, &val, 1);
+ if (ret < 0)
+ return ret;
+
+ return !!(val & BIT(offset));
+}
+
+static void ad7768_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct ad7768_state *st = gpiochip_get_data(chip);
+ unsigned int val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+ ret = ad7768_spi_reg_read(st, AD7768_REG_GPIO_CONTROL, &val, 1);
+ if (ret < 0)
+ return;
+
+ if (val & BIT(offset))
+ ad7768_spi_reg_write_masked(st,
+ AD7768_REG_GPIO_WRITE,
+ BIT(offset),
+ (value << offset));
+}
+
+static int ad7768_gpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+ struct ad7768_state *st = gpiochip_get_data(chip);
+
+ if (!(st->gpio_avail_map & BIT(offset)))
+ return -ENODEV;
+
+ st->gpio_avail_map &= ~BIT(offset);
+
+ return 0;
+}
+
+static int ad7768_gpio_init(struct ad7768_state *st)
+{
+ int ret;
+
+ ret = ad7768_spi_reg_write(st,
+ AD7768_REG_GPIO_CONTROL,
+ AD7768_GPIO_UNIVERSAL_EN);
+ if (ret < 0)
+ return ret;
+
+ st->gpio_avail_map = AD7768_GPIO_CONTROL_MSK;
+ st->gpiochip.label = "ad7768_1_gpios";
+ st->gpiochip.base = -1;
+ st->gpiochip.ngpio = 4;
+ st->gpiochip.parent = &st->spi->dev;
+ st->gpiochip.can_sleep = true;
+ st->gpiochip.direction_input = ad7768_gpio_direction_input;
+ st->gpiochip.direction_output = ad7768_gpio_direction_output;
+ st->gpiochip.get = ad7768_gpio_get;
+ st->gpiochip.set = ad7768_gpio_set;
+ st->gpiochip.request = ad7768_gpio_request;
+ st->gpiochip.owner = THIS_MODULE;
+
+ return gpiochip_add_data(&st->gpiochip, st);
+}
+
static int ad7768_set_freq(struct ad7768_state *st,
unsigned int freq)
{
@@ -538,6 +655,10 @@ static int ad7768_setup(struct ad7768_state *st)
if (IS_ERR(st->gpio_sync_in))
return PTR_ERR(st->gpio_sync_in);
+ ret = ad7768_gpio_init(st);
+ if (ret < 0)
+ return ret;
+
/* Set the default sampling frequency to 32000 kSPS */
return ad7768_set_freq(st, 32000);
}
--
2.34.1
