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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>
This commit is contained in:
Justin Chen
Jonathan Cameron
parent
13814627c9
commit
c97dce792d
1 changed files with 194 additions and 6 deletions
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@ -17,6 +17,7 @@
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/gpio/driver.h>
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#include <linux/interrupt.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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@ -36,12 +37,15 @@
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*/
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#define TI_ADS7950_VA_MV_ACPI_DEFAULT 5000
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#define TI_ADS7950_CR_GPIO BIT(14)
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#define TI_ADS7950_CR_MANUAL BIT(12)
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#define TI_ADS7950_CR_WRITE BIT(11)
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#define TI_ADS7950_CR_CHAN(ch) ((ch) << 7)
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#define TI_ADS7950_CR_RANGE_5V BIT(6)
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#define TI_ADS7950_CR_GPIO_DATA BIT(4)
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#define TI_ADS7950_MAX_CHAN 16
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#define TI_ADS7950_NUM_GPIOS 4
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#define TI_ADS7950_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(__be16))
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@ -49,6 +53,16 @@
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#define TI_ADS7950_EXTRACT(val, dec, bits) \
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(((val) >> (dec)) & ((1 << (bits)) - 1))
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#define TI_ADS7950_MAN_CMD(cmd) (TI_ADS7950_CR_MANUAL | (cmd))
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#define TI_ADS7950_GPIO_CMD(cmd) (TI_ADS7950_CR_GPIO | (cmd))
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/* Manual mode configuration */
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#define TI_ADS7950_MAN_CMD_SETTINGS(st) \
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(TI_ADS7950_MAN_CMD(TI_ADS7950_CR_WRITE | st->cmd_settings_bitmask))
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/* GPIO mode configuration */
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#define TI_ADS7950_GPIO_CMD_SETTINGS(st) \
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(TI_ADS7950_GPIO_CMD(st->gpio_cmd_settings_bitmask))
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struct ti_ads7950_state {
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struct spi_device *spi;
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struct spi_transfer ring_xfer;
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@ -58,11 +72,34 @@ struct ti_ads7950_state {
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/* Lock to protect the spi xfer buffers */
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struct mutex slock;
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struct gpio_chip chip;
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struct regulator *reg;
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unsigned int vref_mv;
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unsigned int settings;
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/*
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* Bitmask of lower 7 bits used for configuration
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* These bits only can be written when TI_ADS7950_CR_WRITE
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* is set, otherwise it retains its original state.
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* [0-3] GPIO signal
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* [4] Set following frame to return GPIO signal values
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* [5] Powers down device
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* [6] Sets Vref range1(2.5v) or range2(5v)
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*
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* Bits present on Manual/Auto1/Auto2 commands
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*/
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unsigned int cmd_settings_bitmask;
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/*
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* Bitmask of GPIO command
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* [0-3] GPIO direction
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* [4-6] Different GPIO alarm mode configurations
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* [7] GPIO 2 as device range input
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* [8] GPIO 3 as device power down input
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* [9] Reset all registers
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* [10-11] N/A
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*/
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unsigned int gpio_cmd_settings_bitmask;
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/*
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* DMA (thus cache coherency maintenance) requires the
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@ -251,7 +288,7 @@ static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev,
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len = 0;
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for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) {
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cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings;
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cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(i));
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st->tx_buf[len++] = cmd;
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}
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@ -292,8 +329,7 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
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int ret, cmd;
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mutex_lock(&st->slock);
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cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
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cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(ch));
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st->single_tx = cmd;
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ret = spi_sync(st->spi, &st->scan_single_msg);
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@ -322,7 +358,7 @@ static int ti_ads7950_get_range(struct ti_ads7950_state *st)
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vref /= 1000;
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}
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if (st->settings & TI_ADS7950_CR_RANGE_5V)
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if (st->cmd_settings_bitmask & TI_ADS7950_CR_RANGE_5V)
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vref *= 2;
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return vref;
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@ -367,6 +403,132 @@ static const struct iio_info ti_ads7950_info = {
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.update_scan_mode = ti_ads7950_update_scan_mode,
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};
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static void ti_ads7950_set(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
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struct ti_ads7950_state *st = gpiochip_get_data(chip);
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mutex_lock(&st->slock);
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if (value)
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st->cmd_settings_bitmask |= BIT(offset);
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else
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st->cmd_settings_bitmask &= ~BIT(offset);
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st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
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spi_sync(st->spi, &st->scan_single_msg);
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mutex_unlock(&st->slock);
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}
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static int ti_ads7950_get(struct gpio_chip *chip, unsigned int offset)
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{
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struct ti_ads7950_state *st = gpiochip_get_data(chip);
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int ret;
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mutex_lock(&st->slock);
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/* If set as output, return the output */
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if (st->gpio_cmd_settings_bitmask & BIT(offset)) {
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ret = st->cmd_settings_bitmask & BIT(offset);
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goto out;
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}
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/* GPIO data bit sets SDO bits 12-15 to GPIO input */
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st->cmd_settings_bitmask |= TI_ADS7950_CR_GPIO_DATA;
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st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
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ret = spi_sync(st->spi, &st->scan_single_msg);
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if (ret)
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goto out;
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ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0;
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/* Revert back to original settings */
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st->cmd_settings_bitmask &= ~TI_ADS7950_CR_GPIO_DATA;
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st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
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ret = spi_sync(st->spi, &st->scan_single_msg);
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if (ret)
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goto out;
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out:
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mutex_unlock(&st->slock);
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return ret;
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}
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static int ti_ads7950_get_direction(struct gpio_chip *chip,
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unsigned int offset)
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{
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struct ti_ads7950_state *st = gpiochip_get_data(chip);
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/* Bitmask is inverted from GPIO framework 0=input/1=output */
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return !(st->gpio_cmd_settings_bitmask & BIT(offset));
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}
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static int _ti_ads7950_set_direction(struct gpio_chip *chip, int offset,
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int input)
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{
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struct ti_ads7950_state *st = gpiochip_get_data(chip);
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int ret = 0;
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mutex_lock(&st->slock);
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/* Only change direction if needed */
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if (input && (st->gpio_cmd_settings_bitmask & BIT(offset)))
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st->gpio_cmd_settings_bitmask &= ~BIT(offset);
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else if (!input && !(st->gpio_cmd_settings_bitmask & BIT(offset)))
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st->gpio_cmd_settings_bitmask |= BIT(offset);
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else
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goto out;
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st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
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ret = spi_sync(st->spi, &st->scan_single_msg);
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out:
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mutex_unlock(&st->slock);
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return ret;
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}
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static int ti_ads7950_direction_input(struct gpio_chip *chip,
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unsigned int offset)
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{
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return _ti_ads7950_set_direction(chip, offset, 1);
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}
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static int ti_ads7950_direction_output(struct gpio_chip *chip,
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unsigned int offset, int value)
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{
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ti_ads7950_set(chip, offset, value);
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return _ti_ads7950_set_direction(chip, offset, 0);
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}
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static int ti_ads7950_init_hw(struct ti_ads7950_state *st)
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{
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int ret = 0;
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mutex_lock(&st->slock);
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/* Settings for Manual/Auto1/Auto2 commands */
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/* Default to 5v ref */
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st->cmd_settings_bitmask = TI_ADS7950_CR_RANGE_5V;
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st->single_tx = TI_ADS7950_MAN_CMD_SETTINGS(st);
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ret = spi_sync(st->spi, &st->scan_single_msg);
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if (ret)
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goto out;
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/* Settings for GPIO command */
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st->gpio_cmd_settings_bitmask = 0x0;
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st->single_tx = TI_ADS7950_GPIO_CMD_SETTINGS(st);
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ret = spi_sync(st->spi, &st->scan_single_msg);
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out:
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mutex_unlock(&st->slock);
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return ret;
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}
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static int ti_ads7950_probe(struct spi_device *spi)
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{
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struct ti_ads7950_state *st;
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@ -391,7 +553,6 @@ static int ti_ads7950_probe(struct spi_device *spi)
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spi_set_drvdata(spi, indio_dev);
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st->spi = spi;
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st->settings = TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_RANGE_5V;
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info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data];
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@ -459,14 +620,40 @@ static int ti_ads7950_probe(struct spi_device *spi)
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goto error_disable_reg;
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}
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ret = ti_ads7950_init_hw(st);
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if (ret) {
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dev_err(&spi->dev, "Failed to init adc chip\n");
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goto error_cleanup_ring;
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}
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ret = iio_device_register(indio_dev);
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if (ret) {
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dev_err(&spi->dev, "Failed to register iio device\n");
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goto error_cleanup_ring;
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}
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/* Add GPIO chip */
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st->chip.label = dev_name(&st->spi->dev);
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st->chip.parent = &st->spi->dev;
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st->chip.owner = THIS_MODULE;
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st->chip.base = -1;
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st->chip.ngpio = TI_ADS7950_NUM_GPIOS;
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st->chip.get_direction = ti_ads7950_get_direction;
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st->chip.direction_input = ti_ads7950_direction_input;
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st->chip.direction_output = ti_ads7950_direction_output;
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st->chip.get = ti_ads7950_get;
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st->chip.set = ti_ads7950_set;
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ret = gpiochip_add_data(&st->chip, st);
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if (ret) {
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dev_err(&spi->dev, "Failed to init GPIOs\n");
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goto error_iio_device;
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}
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return 0;
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error_iio_device:
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iio_device_unregister(indio_dev);
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error_cleanup_ring:
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iio_triggered_buffer_cleanup(indio_dev);
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error_disable_reg:
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@ -482,6 +669,7 @@ static int ti_ads7950_remove(struct spi_device *spi)
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struct iio_dev *indio_dev = spi_get_drvdata(spi);
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struct ti_ads7950_state *st = iio_priv(indio_dev);
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gpiochip_remove(&st->chip);
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iio_device_unregister(indio_dev);
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iio_triggered_buffer_cleanup(indio_dev);
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regulator_disable(st->reg);
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