diff options
author | William Breathitt Gray <vilhelm.gray@gmail.com> | 2016-06-13 15:06:48 +0200 |
---|---|---|
committer | Jonathan Cameron <jic23@kernel.org> | 2016-06-27 21:59:11 +0200 |
commit | 765550e4d98d8f5931a3863781acb7c6b995161c (patch) | |
tree | b446cfd3985fd4d9a13f2dd710de481a61a55688 /drivers/iio/dac | |
parent | iio: as3935: improve error reporting in as3935_event_work (diff) | |
download | linux-765550e4d98d8f5931a3863781acb7c6b995161c.tar.xz linux-765550e4d98d8f5931a3863781acb7c6b995161c.zip |
iio: stx104: Add GPIO support for the Apex Embedded Systems STX104
The Apex Embedded Systems STX104 device features eight lines of digital
I/O (four digital inputs and four digital outputs). This patch adds GPIO
support for these eight lines of digital I/O via GPIOLIB.
Cc: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/iio/dac')
-rw-r--r-- | drivers/iio/dac/Kconfig | 11 | ||||
-rw-r--r-- | drivers/iio/dac/stx104.c | 125 |
2 files changed, 129 insertions, 7 deletions
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig index 61d5008bff5c..b3feb0bf3aa3 100644 --- a/drivers/iio/dac/Kconfig +++ b/drivers/iio/dac/Kconfig @@ -246,13 +246,14 @@ config MCP4922 will be called mcp4922. config STX104 - tristate "Apex Embedded Systems STX104 DAC driver" + tristate "Apex Embedded Systems STX104 driver" depends on ISA + select GPIOLIB help - Say yes here to build support for the 2-channel DAC on the Apex - Embedded Systems STX104 integrated analog PC/104 card. The base port - addresses for the devices may be configured via the "base" module - parameter array. + Say yes here to build support for the 2-channel DAC and GPIO on the + Apex Embedded Systems STX104 integrated analog PC/104 card. The base + port addresses for the devices may be configured via the base array + module parameter. config VF610_DAC tristate "Vybrid vf610 DAC driver" diff --git a/drivers/iio/dac/stx104.c b/drivers/iio/dac/stx104.c index 174f4b75ceed..e0f31a12c87f 100644 --- a/drivers/iio/dac/stx104.c +++ b/drivers/iio/dac/stx104.c @@ -14,6 +14,7 @@ #include <linux/bitops.h> #include <linux/device.h> #include <linux/errno.h> +#include <linux/gpio/driver.h> #include <linux/iio/iio.h> #include <linux/iio/types.h> #include <linux/io.h> @@ -21,6 +22,7 @@ #include <linux/isa.h> #include <linux/module.h> #include <linux/moduleparam.h> +#include <linux/spinlock.h> #define STX104_NUM_CHAN 2 @@ -56,6 +58,20 @@ struct stx104_iio { unsigned base; }; +/** + * struct stx104_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @lock: synchronization lock to prevent I/O race conditions + * @base: base port address of the GPIO device + * @out_state: output bits state + */ +struct stx104_gpio { + struct gpio_chip chip; + spinlock_t lock; + unsigned int base; + unsigned int out_state; +}; + static int stx104_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { @@ -95,15 +111,81 @@ static const struct iio_chan_spec stx104_channels[STX104_NUM_CHAN] = { STX104_CHAN(1) }; +static int stx104_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + if (offset < 4) + return 1; + + return 0; +} + +static int stx104_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + if (offset >= 4) + return -EINVAL; + + return 0; +} + +static int stx104_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + if (offset < 4) + return -EINVAL; + + chip->set(chip, offset, value); + return 0; +} + +static int stx104_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); + + if (offset >= 4) + return -EINVAL; + + return !!(inb(stx104gpio->base) & BIT(offset)); +} + +static void stx104_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct stx104_gpio *const stx104gpio = gpiochip_get_data(chip); + const unsigned int mask = BIT(offset) >> 4; + unsigned long flags; + + if (offset < 4) + return; + + spin_lock_irqsave(&stx104gpio->lock, flags); + + if (value) + stx104gpio->out_state |= mask; + else + stx104gpio->out_state &= ~mask; + + outb(stx104gpio->out_state, stx104gpio->base); + + spin_unlock_irqrestore(&stx104gpio->lock, flags); +} + static int stx104_probe(struct device *dev, unsigned int id) { struct iio_dev *indio_dev; struct stx104_iio *priv; + struct stx104_gpio *stx104gpio; + int err; indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); if (!indio_dev) return -ENOMEM; + stx104gpio = devm_kzalloc(dev, sizeof(*stx104gpio), GFP_KERNEL); + if (!stx104gpio) + return -ENOMEM; + if (!devm_request_region(dev, base[id], STX104_EXTENT, dev_name(dev))) { dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", @@ -124,14 +206,53 @@ static int stx104_probe(struct device *dev, unsigned int id) outw(0, base[id] + 4); outw(0, base[id] + 6); - return devm_iio_device_register(dev, indio_dev); + err = devm_iio_device_register(dev, indio_dev); + if (err) { + dev_err(dev, "IIO device registering failed (%d)\n", err); + return err; + } + + stx104gpio->chip.label = dev_name(dev); + stx104gpio->chip.parent = dev; + stx104gpio->chip.owner = THIS_MODULE; + stx104gpio->chip.base = -1; + stx104gpio->chip.ngpio = 8; + stx104gpio->chip.get_direction = stx104_gpio_get_direction; + stx104gpio->chip.direction_input = stx104_gpio_direction_input; + stx104gpio->chip.direction_output = stx104_gpio_direction_output; + stx104gpio->chip.get = stx104_gpio_get; + stx104gpio->chip.set = stx104_gpio_set; + stx104gpio->base = base[id] + 3; + stx104gpio->out_state = 0x0; + + spin_lock_init(&stx104gpio->lock); + + dev_set_drvdata(dev, stx104gpio); + + err = gpiochip_add_data(&stx104gpio->chip, stx104gpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + return 0; +} + +static int stx104_remove(struct device *dev, unsigned int id) +{ + struct stx104_gpio *const stx104gpio = dev_get_drvdata(dev); + + gpiochip_remove(&stx104gpio->chip); + + return 0; } static struct isa_driver stx104_driver = { .probe = stx104_probe, .driver = { .name = "stx104" - } + }, + .remove = stx104_remove }; static void __exit stx104_exit(void) |