From: Justin Chen <[email protected]> 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 <[email protected]> --- drivers/iio/adc/ti-ads7950.c | 166 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 164 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c index 0ad6359..c54706ad 100644 --- a/drivers/iio/adc/ti-ads7950.c +++ b/drivers/iio/adc/ti-ads7950.c @@ -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> @@ -36,10 +37,14 @@ */ #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(5) +#define TI_ADS7950_NUM_GPIOS 4 +#define TI_ADS7950_GPIO_MASK GENMASK(TI_ADS7950_NUM_GPIOS - 1, 0) #define TI_ADS7950_MAX_CHAN 16 @@ -56,11 +61,17 @@ struct ti_ads7950_state { struct spi_message ring_msg; struct spi_message scan_single_msg; + struct iio_dev *indio_dev; + struct gpio_chip *chip; + struct regulator *reg; unsigned int vref_mv; unsigned int settings; + unsigned int gpio_direction_bitmask; + unsigned int gpio_signal_bitmask; + /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -248,7 +259,8 @@ 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_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); st->tx_buf[len++] = cmd; } @@ -288,7 +300,8 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) mutex_lock(&indio_dev->mlock); - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; + cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings + | (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK); st->single_tx = cmd; ret = spi_sync(st->spi, &st->scan_single_msg); @@ -362,10 +375,149 @@ 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->indio_dev->mlock); + + if (value) + st->gpio_signal_bitmask |= BIT(offset); + else + st->gpio_signal_bitmask &= ~BIT(offset); + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | + (st->gpio_signal_bitmask & TI_ADS7950_GPIO_MASK)); + spi_sync(st->spi, &st->scan_single_msg); + + mutex_unlock(&st->indio_dev->mlock); +} + +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->indio_dev->mlock); + + /* If set as output, return the output */ + if (st->gpio_direction_bitmask & BIT(offset)) { + ret = st->gpio_signal_bitmask & BIT(offset); + goto out; + } + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_WRITE | + TI_ADS7950_CR_GPIO_DATA); + ret = spi_sync(st->spi, &st->scan_single_msg); + if (ret) + goto out; + + ret = ((st->single_rx >> 12) & BIT(offset)) ? 1 : 0; + +out: + mutex_unlock(&st->indio_dev->mlock); + + return ret; +} + +static int ti_ads7950_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct ti_ads7950_state *st = gpiochip_get_data(chip); + + return !(st->gpio_direction_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->indio_dev->mlock); + + if (input && (st->gpio_direction_bitmask & BIT(offset))) + st->gpio_direction_bitmask &= ~BIT(offset); + else if (!input && !(st->gpio_direction_bitmask & BIT(offset))) + st->gpio_direction_bitmask |= BIT(offset); + else + goto out; + + + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | + (st->gpio_direction_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + +out: + mutex_unlock(&st->indio_dev->mlock); + + 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_gpio(struct ti_ads7950_state *st) +{ + int ret; + + /* Initialize GPIO */ + mutex_lock(&st->indio_dev->mlock); + + /* Default to GPIO input */ + st->gpio_direction_bitmask = 0x0; + st->single_tx = cpu_to_be16(TI_ADS7950_CR_GPIO | + (st->gpio_direction_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + mutex_unlock(&st->indio_dev->mlock); + if (ret) + return ret; + + /* Default to signal low */ + st->gpio_signal_bitmask = 0x0; + st->single_tx = cpu_to_be16(TI_ADS7950_CR_MANUAL | + TI_ADS7950_CR_WRITE | + (st->gpio_signal_bitmask & + TI_ADS7950_GPIO_MASK)); + ret = spi_sync(st->spi, &st->scan_single_msg); + mutex_unlock(&st->indio_dev->mlock); + if (ret) + return ret; + + /* 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; + + return gpiochip_add_data(st->chip, st); +} + static int ti_ads7950_probe(struct spi_device *spi) { struct ti_ads7950_state *st; struct iio_dev *indio_dev; + struct gpio_chip *chip; const struct ti_ads7950_chip_info *info; int ret; @@ -381,6 +533,10 @@ static int ti_ads7950_probe(struct spi_device *spi) if (!indio_dev) return -ENOMEM; + chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + st = iio_priv(indio_dev); spi_set_drvdata(spi, indio_dev); @@ -396,6 +552,8 @@ static int ti_ads7950_probe(struct spi_device *spi) indio_dev->channels = info->channels; indio_dev->num_channels = info->num_channels; indio_dev->info = &ti_ads7950_info; + st->indio_dev = indio_dev; + st->chip = chip; /* build spi ring message */ spi_message_init(&st->ring_msg); @@ -457,6 +615,10 @@ static int ti_ads7950_probe(struct spi_device *spi) goto error_cleanup_ring; } + ret = ti_ads7950_init_gpio(st); + if (ret) + dev_warn(&spi->dev, "Unable to initialize GPIOs\n"); + return 0; error_cleanup_ring: -- 2.7.4
