iio: adc: ti-ads7950: add GPIO support
The ADS79XX has GPIO pins that can be used. Add support for the GPIO pins using the GPIO chip framework. Signed-off-by: Justin Chen <justinpopo6@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>hifive-unleashed-5.2
Justin Chen
Jonathan Cameron
parent
13814627c9
commit
c97dce792d
|
|
@ -17,6 +17,7 @@
|
|||
#include <linux/bitops.h>
|
||||
#include <linux/device.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/gpio/driver.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
|
|
@ -36,12 +37,15 @@
|
|||
*/
|
||||
#define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000
|
||||
|
||||
#define TI_ADS7950_CR_GPIO BIT(14)
|
||||
#define TI_ADS7950_CR_MANUAL BIT(12)
|
||||
#define TI_ADS7950_CR_WRITE BIT(11)
|
||||
#define TI_ADS7950_CR_CHAN(ch) ((ch) << 7)
|
||||
#define TI_ADS7950_CR_RANGE_5V BIT(6)
|
||||
#define TI_ADS7950_CR_GPIO_DATA BIT(4)
|
||||
|
||||
#define TI_ADS7950_MAX_CHAN 16
|
||||
#define TI_ADS7950_NUM_GPIOS 4
|
||||
|
||||
#define TI_ADS7950_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(__be16))
|
||||
|
||||
|
|
@ -49,6 +53,16 @@
|
|||
#define TI_ADS7950_EXTRACT(val, dec, bits) \
|
||||
(((val) >> (dec)) & ((1 << (bits)) - 1))
|
||||
|
||||
#define TI_ADS7950_MAN_CMD(cmd) (TI_ADS7950_CR_MANUAL | (cmd))
|
||||
#define TI_ADS7950_GPIO_CMD(cmd) (TI_ADS7950_CR_GPIO | (cmd))
|
||||
|
||||
/* Manual mode configuration */
|
||||
#define TI_ADS7950_MAN_CMD_SETTINGS(st) \
|
||||
(TI_ADS7950_MAN_CMD(TI_ADS7950_CR_WRITE | st->cmd_settings_bitmask))
|
||||
/* GPIO mode configuration */
|
||||
#define TI_ADS7950_GPIO_CMD_SETTINGS(st) \
|
||||
(TI_ADS7950_GPIO_CMD(st->gpio_cmd_settings_bitmask))
|
||||
|
||||
struct ti_ads7950_state {
|
||||
struct spi_device *spi;
|
||||
struct spi_transfer ring_xfer;
|
||||
|
|
@ -58,11 +72,34 @@ struct ti_ads7950_state {
|
|||
|
||||
/* Lock to protect the spi xfer buffers */
|
||||
struct mutex slock;
|
||||
struct gpio_chip chip;
|
||||
|
||||
struct regulator *reg;
|
||||
unsigned int vref_mv;
|
||||
|
||||
unsigned int settings;
|
||||
/*
|
||||
* Bitmask of lower 7 bits used for configuration
|
||||
* These bits only can be written when TI_ADS7950_CR_WRITE
|
||||
* is set, otherwise it retains its original state.
|
||||
* [0-3] GPIO signal
|
||||
* [4] Set following frame to return GPIO signal values
|
||||
* [5] Powers down device
|
||||
* [6] Sets Vref range1(2.5v) or range2(5v)
|
||||
*
|
||||
* Bits present on Manual/Auto1/Auto2 commands
|
||||
*/
|
||||
unsigned int cmd_settings_bitmask;
|
||||
|
||||
/*
|
||||
* Bitmask of GPIO command
|
||||
* [0-3] GPIO direction
|
||||
* [4-6] Different GPIO alarm mode configurations
|
||||
* [7] GPIO 2 as device range input
|
||||
* [8] GPIO 3 as device power down input
|
||||
* [9] Reset all registers
|
||||
* [10-11] N/A
|
||||
*/
|
||||
unsigned int gpio_cmd_settings_bitmask;
|
||||
|
||||
/*
|
||||
* DMA (thus cache coherency maintenance) requires the
|
||||
|
|
@ -251,7 +288,7 @@ static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev,
|
|||
|
||||
len = 0;
|
||||
for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) {
|
||||
cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings;
|
||||
cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(i));
|
||||
st->tx_buf[len++] = cmd;
|
||||
}
|
||||
|
||||
|
|
@ -292,8 +329,7 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
|
|||
int ret, cmd;
|
||||
|
||||
mutex_lock(&st->slock);
|
||||
|
||||
cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
|
||||
cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(ch));
|
||||
st->single_tx = cmd;
|
||||
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
|
|
@ -322,7 +358,7 @@ static int ti_ads7950_get_range(struct ti_ads7950_state *st)
|
|||
vref /= 1000;
|
||||
}
|
||||
|
||||
if (st->settings & TI_ADS7950_CR_RANGE_5V)
|
||||
if (st->cmd_settings_bitmask & TI_ADS7950_CR_RANGE_5V)
|
||||
vref *= 2;
|
||||
|
||||
return vref;
|
||||
|
|
@ -367,6 +403,132 @@ static const struct iio_info ti_ads7950_info = {
|
|||
.update_scan_mode = ti_ads7950_update_scan_mode,
|
||||
};
|
||||
|
||||
static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset,
|
||||
int value)
|
||||
{
|
||||
struct ti_ads7950_state *st = gpiochip_get_data(chip);
|
||||
|
||||
mutex_lock(&st->slock);
|
||||
|
||||
if (value)
|
||||
st->cmd_settings_bitmask |= BIT(offset);
|
||||
else
|
||||
st->cmd_settings_bitmask &= ~BIT(offset);
|
||||
|
||||
st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
|
||||
spi_sync(st->spi, &st->scan_single_msg);
|
||||
|
||||
mutex_unlock(&st->slock);
|
||||
}
|
||||
|
||||
static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
|
||||
{
|
||||
struct ti_ads7950_state *st = gpiochip_get_data(chip);
|
||||
int ret;
|
||||
|
||||
mutex_lock(&st->slock);
|
||||
|
||||
/* If set as output, return the output */
|
||||
if (st->gpio_cmd_settings_bitmask & BIT(offset)) {
|
||||
ret = st->cmd_settings_bitmask & BIT(offset);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* GPIO data bit sets SDO bits 12-15 to GPIO input */
|
||||
st->cmd_settings_bitmask |= TI_ADS7950_CR_GPIO_DATA;
|
||||
st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0;
|
||||
|
||||
/* Revert back to original settings */
|
||||
st->cmd_settings_bitmask &= ~TI_ADS7950_CR_GPIO_DATA;
|
||||
st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
out:
|
||||
mutex_unlock(&st->slock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ti_ads7950_get_direction(struct gpio_chip *chip,
|
||||
unsigned int offset)
|
||||
{
|
||||
struct ti_ads7950_state *st = gpiochip_get_data(chip);
|
||||
|
||||
/* Bitmask is inverted from GPIO framework 0=input/1=output */
|
||||
return !(st->gpio_cmd_settings_bitmask & BIT(offset));
|
||||
}
|
||||
|
||||
static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset,
|
||||
int input)
|
||||
{
|
||||
struct ti_ads7950_state *st = gpiochip_get_data(chip);
|
||||
int ret = 0;
|
||||
|
||||
mutex_lock(&st->slock);
|
||||
|
||||
/* Only change direction if needed */
|
||||
if (input && (st->gpio_cmd_settings_bitmask & BIT(offset)))
|
||||
st->gpio_cmd_settings_bitmask &= ~BIT(offset);
|
||||
else if (!input && !(st->gpio_cmd_settings_bitmask & BIT(offset)))
|
||||
st->gpio_cmd_settings_bitmask |= BIT(offset);
|
||||
else
|
||||
goto out;
|
||||
|
||||
st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
|
||||
out:
|
||||
mutex_unlock(&st->slock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ti_ads7950_direction_input(struct gpio_chip *chip,
|
||||
unsigned int offset)
|
||||
{
|
||||
return _ti_ads7950_set_direction(chip, offset, 1);
|
||||
}
|
||||
|
||||
static int ti_ads7950_direction_output(struct gpio_chip *chip,
|
||||
unsigned int offset, int value)
|
||||
{
|
||||
ti_ads7950_set(chip, offset, value);
|
||||
|
||||
return _ti_ads7950_set_direction(chip, offset, 0);
|
||||
}
|
||||
|
||||
static int ti_ads7950_init_hw(struct ti_ads7950_state *st)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
mutex_lock(&st->slock);
|
||||
|
||||
/* Settings for Manual/Auto1/Auto2 commands */
|
||||
/* Default to 5v ref */
|
||||
st->cmd_settings_bitmask = TI_ADS7950_CR_RANGE_5V;
|
||||
st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
if (ret)
|
||||
goto out;
|
||||
|
||||
/* Settings for GPIO command */
|
||||
st->gpio_cmd_settings_bitmask = 0x0;
|
||||
st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
|
||||
ret = spi_sync(st->spi, &st->scan_single_msg);
|
||||
|
||||
out:
|
||||
mutex_unlock(&st->slock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ti_ads7950_probe(struct spi_device *spi)
|
||||
{
|
||||
struct ti_ads7950_state *st;
|
||||
|
|
@ -391,7 +553,6 @@ static int ti_ads7950_probe(struct spi_device *spi)
|
|||
spi_set_drvdata(spi, indio_dev);
|
||||
|
||||
st->spi = spi;
|
||||
st->settings = TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_RANGE_5V;
|
||||
|
||||
info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data];
|
||||
|
||||
|
|
@ -459,14 +620,40 @@ static int ti_ads7950_probe(struct spi_device *spi)
|
|||
goto error_disable_reg;
|
||||
}
|
||||
|
||||
ret = ti_ads7950_init_hw(st);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev, "Failed to init adc chip\n");
|
||||
goto error_cleanup_ring;
|
||||
}
|
||||
|
||||
ret = iio_device_register(indio_dev);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev, "Failed to register iio device\n");
|
||||
goto error_cleanup_ring;
|
||||
}
|
||||
|
||||
/* Add GPIO chip */
|
||||
st->chip.label = dev_name(&st->spi->dev);
|
||||
st->chip.parent = &st->spi->dev;
|
||||
st->chip.owner = THIS_MODULE;
|
||||
st->chip.base = -1;
|
||||
st->chip.ngpio = TI_ADS7950_NUM_GPIOS;
|
||||
st->chip.get_direction = ti_ads7950_get_direction;
|
||||
st->chip.direction_input = ti_ads7950_direction_input;
|
||||
st->chip.direction_output = ti_ads7950_direction_output;
|
||||
st->chip.get = ti_ads7950_get;
|
||||
st->chip.set = ti_ads7950_set;
|
||||
|
||||
ret = gpiochip_add_data(&st->chip, st);
|
||||
if (ret) {
|
||||
dev_err(&spi->dev, "Failed to init GPIOs\n");
|
||||
goto error_iio_device;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
error_iio_device:
|
||||
iio_device_unregister(indio_dev);
|
||||
error_cleanup_ring:
|
||||
iio_triggered_buffer_cleanup(indio_dev);
|
||||
error_disable_reg:
|
||||
|
|
@ -482,6 +669,7 @@ static int ti_ads7950_remove(struct spi_device *spi)
|
|||
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
||||
struct ti_ads7950_state *st = iio_priv(indio_dev);
|
||||
|
||||
gpiochip_remove(&st->chip);
|
||||
iio_device_unregister(indio_dev);
|
||||
iio_triggered_buffer_cleanup(indio_dev);
|
||||
regulator_disable(st->reg);
|
||||
|
|
|
|||
Loading…
Reference in New Issue