diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak8975.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak8975.c | 103 |
1 files changed, 98 insertions, 5 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c index af6c320a534e..7105f22d6cd7 100644 --- a/drivers/iio/magnetometer/ak8975.c +++ b/drivers/iio/magnetometer/ak8975.c @@ -24,11 +24,13 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/i2c.h> +#include <linux/interrupt.h> #include <linux/err.h> #include <linux/mutex.h> #include <linux/delay.h> - +#include <linux/bitops.h> #include <linux/gpio.h> +#include <linux/of_gpio.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> @@ -82,6 +84,7 @@ */ #define AK8975_MAX_CONVERSION_TIMEOUT 500 #define AK8975_CONVERSION_DONE_POLL_TIME 10 +#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) /* * Per-instance context data for the device. @@ -94,6 +97,9 @@ struct ak8975_data { long raw_to_gauss[3]; u8 reg_cache[AK8975_MAX_REGS]; int eoc_gpio; + int eoc_irq; + wait_queue_head_t data_ready_queue; + unsigned long flags; }; static const int ak8975_index_to_reg[] = { @@ -123,6 +129,51 @@ static int ak8975_write_data(struct i2c_client *client, } /* + * Handle data ready irq + */ +static irqreturn_t ak8975_irq_handler(int irq, void *data) +{ + struct ak8975_data *ak8975 = data; + + set_bit(0, &ak8975->flags); + wake_up(&ak8975->data_ready_queue); + + return IRQ_HANDLED; +} + +/* + * Install data ready interrupt handler + */ +static int ak8975_setup_irq(struct ak8975_data *data) +{ + struct i2c_client *client = data->client; + int rc; + int irq; + + if (client->irq) + irq = client->irq; + else + irq = gpio_to_irq(data->eoc_gpio); + + rc = request_irq(irq, ak8975_irq_handler, + IRQF_TRIGGER_RISING | IRQF_ONESHOT, + dev_name(&client->dev), data); + if (rc < 0) { + dev_err(&client->dev, + "irq %d request failed, (gpio %d): %d\n", + irq, data->eoc_gpio, rc); + return rc; + } + + init_waitqueue_head(&data->data_ready_queue); + clear_bit(0, &data->flags); + data->eoc_irq = irq; + + return rc; +} + + +/* * Perform some start-of-day setup, including reading the asa calibration * values and caching them. */ @@ -170,6 +221,16 @@ static int ak8975_setup(struct i2c_client *client) AK8975_REG_CNTL_MODE_POWER_DOWN, AK8975_REG_CNTL_MODE_MASK, AK8975_REG_CNTL_MODE_SHIFT); + + if (data->eoc_gpio > 0 || client->irq) { + ret = ak8975_setup_irq(data); + if (ret < 0) { + dev_err(&client->dev, + "Error setting data ready interrupt\n"); + return ret; + } + } + if (ret < 0) { dev_err(&client->dev, "Error in setting power-down mode\n"); return ret; @@ -266,9 +327,23 @@ static int wait_conversion_complete_polled(struct ak8975_data *data) dev_err(&client->dev, "Conversion timeout happened\n"); return -EINVAL; } + return read_status; } +/* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */ +static int wait_conversion_complete_interrupt(struct ak8975_data *data) +{ + int ret; + + ret = wait_event_timeout(data->data_ready_queue, + test_bit(0, &data->flags), + AK8975_DATA_READY_TIMEOUT); + clear_bit(0, &data->flags); + + return ret > 0 ? 0 : -ETIME; +} + /* * Emits the raw flux value for the x, y, or z axis. */ @@ -294,13 +369,16 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) } /* Wait for the conversion to complete. */ - if (gpio_is_valid(data->eoc_gpio)) + if (data->eoc_irq) + ret = wait_conversion_complete_interrupt(data); + else if (gpio_is_valid(data->eoc_gpio)) ret = wait_conversion_complete_gpio(data); else ret = wait_conversion_complete_polled(data); if (ret < 0) goto exit; + /* This will be executed only for non-interrupt based waiting case */ if (ret & AK8975_REG_ST1_DRDY_MASK) { ret = i2c_smbus_read_byte_data(client, AK8975_REG_ST2); if (ret < 0) { @@ -384,10 +462,15 @@ static int ak8975_probe(struct i2c_client *client, int err; /* Grab and set up the supplied GPIO. */ - if (client->dev.platform_data == NULL) - eoc_gpio = -1; - else + if (client->dev.platform_data) eoc_gpio = *(int *)(client->dev.platform_data); + else if (client->dev.of_node) + eoc_gpio = of_get_gpio(client->dev.of_node, 0); + else + eoc_gpio = -1; + + if (eoc_gpio == -EPROBE_DEFER) + return -EPROBE_DEFER; /* We may not have a GPIO based IRQ to scan, that is fine, we will poll if so */ @@ -409,6 +492,11 @@ static int ak8975_probe(struct i2c_client *client, } data = iio_priv(indio_dev); i2c_set_clientdata(client, indio_dev); + + data->client = client; + data->eoc_gpio = eoc_gpio; + data->eoc_irq = 0; + /* Perform some basic start-of-day setup of the device. */ err = ak8975_setup(client); if (err < 0) { @@ -433,6 +521,8 @@ static int ak8975_probe(struct i2c_client *client, exit_free_iio: iio_device_free(indio_dev); + if (data->eoc_irq) + free_irq(data->eoc_irq, data); exit_gpio: if (gpio_is_valid(eoc_gpio)) gpio_free(eoc_gpio); @@ -447,6 +537,9 @@ static int ak8975_remove(struct i2c_client *client) iio_device_unregister(indio_dev); + if (data->eoc_irq) + free_irq(data->eoc_irq, data); + if (gpio_is_valid(data->eoc_gpio)) gpio_free(data->eoc_gpio); |