diff options
Diffstat (limited to 'drivers/iio/adc/ti-ads7950.c')
| -rw-r--r-- | drivers/iio/adc/ti-ads7950.c | 219 |
1 files changed, 209 insertions, 10 deletions
diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c index 0ad63592cc3c..2e66e4d586ff 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> @@ -36,12 +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; @@ -56,10 +70,36 @@ struct ti_ads7950_state { struct spi_message ring_msg; struct spi_message scan_single_msg; + /* 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 @@ -248,7 +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; } @@ -268,6 +308,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p) struct ti_ads7950_state *st = iio_priv(indio_dev); int ret; + mutex_lock(&st->slock); ret = spi_sync(st->spi, &st->ring_msg); if (ret < 0) goto out; @@ -276,6 +317,7 @@ static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p) iio_get_time_ns(indio_dev)); out: + mutex_unlock(&st->slock); iio_trigger_notify_done(indio_dev->trig); return IRQ_HANDLED; @@ -286,9 +328,8 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) struct ti_ads7950_state *st = iio_priv(indio_dev); int ret, cmd; - mutex_lock(&indio_dev->mlock); - - cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings; + mutex_lock(&st->slock); + cmd = TI_ADS7950_MAN_CMD(TI_ADS7950_CR_CHAN(ch)); st->single_tx = cmd; ret = spi_sync(st->spi, &st->scan_single_msg); @@ -298,7 +339,7 @@ static int ti_ads7950_scan_direct(struct iio_dev *indio_dev, unsigned int ch) ret = st->single_rx; out: - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->slock); return ret; } @@ -317,7 +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; @@ -362,6 +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; @@ -386,7 +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]; @@ -432,16 +598,19 @@ static int ti_ads7950_probe(struct spi_device *spi) if (ACPI_COMPANION(&spi->dev)) st->vref_mv = TI_ADS7950_VA_MV_ACPI_DEFAULT; + mutex_init(&st->slock); + st->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(st->reg)) { dev_err(&spi->dev, "Failed get get regulator \"vref\"\n"); - return PTR_ERR(st->reg); + ret = PTR_ERR(st->reg); + goto error_destroy_mutex; } ret = regulator_enable(st->reg); if (ret) { dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n"); - return ret; + goto error_destroy_mutex; } ret = iio_triggered_buffer_setup(indio_dev, NULL, @@ -451,18 +620,46 @@ 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: regulator_disable(st->reg); +error_destroy_mutex: + mutex_destroy(&st->slock); return ret; } @@ -472,9 +669,11 @@ 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); + mutex_destroy(&st->slock); return 0; } |