diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak8975.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak8975.c | 192 |
1 files changed, 169 insertions, 23 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c index af6c320a534..ea08313af0d 100644 --- a/drivers/iio/magnetometer/ak8975.c +++ b/drivers/iio/magnetometer/ak8975.c @@ -24,11 +24,14 @@ #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/acpi.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> @@ -82,6 +85,15 @@ */ #define AK8975_MAX_CONVERSION_TIMEOUT 500 #define AK8975_CONVERSION_DONE_POLL_TIME 10 +#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) +#define RAW_TO_GAUSS_8975(asa) ((((asa) + 128) * 3000) / 256) +#define RAW_TO_GAUSS_8963(asa) ((((asa) + 128) * 6000) / 256) + +/* Compatible Asahi Kasei Compass parts */ +enum asahi_compass_chipset { + AK8975, + AK8963, +}; /* * Per-instance context data for the device. @@ -94,6 +106,10 @@ 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; + enum asahi_compass_chipset chipset; }; static const int ak8975_index_to_reg[] = { @@ -123,6 +139,51 @@ 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 +231,16 @@ 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; @@ -202,17 +273,29 @@ static int ak8975_setup(struct i2c_client *client) * * HuT = H * 1229/4096, or roughly, 3/10. * - * Since 1uT = 100 gauss, our final scale factor becomes: + * Since 1uT = 0.01 gauss, our final scale factor becomes: * - * Hadj = H * ((ASA + 128) / 256) * 3/10 * 100 - * Hadj = H * ((ASA + 128) * 30 / 256 + * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100 + * Hadj = H * ((ASA + 128) * 0.003) / 256 * * Since ASA doesn't change, we cache the resultant scale factor into the * device context in ak8975_setup(). */ - data->raw_to_gauss[0] = ((data->asa[0] + 128) * 30) >> 8; - data->raw_to_gauss[1] = ((data->asa[1] + 128) * 30) >> 8; - data->raw_to_gauss[2] = ((data->asa[2] + 128) * 30) >> 8; + if (data->chipset == AK8963) { + /* + * H range is +-8190 and magnetometer range is +-4912. + * So HuT using the above explanation for 8975, + * 4912/8190 = ~ 6/10. + * So the Hadj should use 6/10 instead of 3/10. + */ + data->raw_to_gauss[0] = RAW_TO_GAUSS_8963(data->asa[0]); + data->raw_to_gauss[1] = RAW_TO_GAUSS_8963(data->asa[1]); + data->raw_to_gauss[2] = RAW_TO_GAUSS_8963(data->asa[2]); + } else { + data->raw_to_gauss[0] = RAW_TO_GAUSS_8975(data->asa[0]); + data->raw_to_gauss[1] = RAW_TO_GAUSS_8975(data->asa[1]); + data->raw_to_gauss[2] = RAW_TO_GAUSS_8975(data->asa[2]); + } return 0; } @@ -266,9 +349,23 @@ 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. */ @@ -276,8 +373,6 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) { struct ak8975_data *data = iio_priv(indio_dev); struct i2c_client *client = data->client; - u16 meas_reg; - s16 raw; int ret; mutex_lock(&data->lock); @@ -294,13 +389,16 @@ 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) { @@ -322,16 +420,11 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) dev_err(&client->dev, "Read axis data fails\n"); goto exit; } - meas_reg = ret; mutex_unlock(&data->lock); - /* Endian conversion of the measured values. */ - raw = (s16) (le16_to_cpu(meas_reg)); - /* Clamp to valid range. */ - raw = clamp_t(s16, raw, -4096, 4095); - *val = raw; + *val = clamp_t(s16, ret, -4096, 4095); return IIO_VAL_INT; exit: @@ -350,8 +443,9 @@ static int ak8975_read_raw(struct iio_dev *indio_dev, case IIO_CHAN_INFO_RAW: return ak8975_read_axis(indio_dev, chan->address, val); case IIO_CHAN_INFO_SCALE: - *val = data->raw_to_gauss[chan->address]; - return IIO_VAL_INT; + *val = 0; + *val2 = data->raw_to_gauss[chan->address]; + return IIO_VAL_INT_PLUS_MICRO; } return -EINVAL; } @@ -375,6 +469,27 @@ static const struct iio_info ak8975_info = { .driver_module = THIS_MODULE, }; +static const struct acpi_device_id ak_acpi_match[] = { + {"AK8975", AK8975}, + {"AK8963", AK8963}, + {"INVN6500", AK8963}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, ak_acpi_match); + +static char *ak8975_match_acpi_device(struct device *dev, + enum asahi_compass_chipset *chipset) +{ + const struct acpi_device_id *id; + + id = acpi_match_device(dev->driver->acpi_match_table, dev); + if (!id) + return NULL; + *chipset = (int)id->driver_data; + + return (char *)dev_name(dev); +} + static int ak8975_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -382,12 +497,18 @@ static int ak8975_probe(struct i2c_client *client, struct iio_dev *indio_dev; int eoc_gpio; int err; + char *name = NULL; /* 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 +530,24 @@ 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; + + /* id will be NULL when enumerated via ACPI */ + if (id) { + data->chipset = + (enum asahi_compass_chipset)(id->driver_data); + name = (char *) id->name; + } else if (ACPI_HANDLE(&client->dev)) + name = ak8975_match_acpi_device(&client->dev, &data->chipset); + else { + err = -ENOSYS; + goto exit_free_iio; + } + dev_dbg(&client->dev, "Asahi compass chip %s\n", name); + /* Perform some basic start-of-day setup of the device. */ err = ak8975_setup(client); if (err < 0) { @@ -424,7 +563,7 @@ static int ak8975_probe(struct i2c_client *client, indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); indio_dev->info = &ak8975_info; indio_dev->modes = INDIO_DIRECT_MODE; - + indio_dev->name = name; err = iio_device_register(indio_dev); if (err < 0) goto exit_free_iio; @@ -433,6 +572,8 @@ 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 +588,9 @@ 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); @@ -456,7 +600,8 @@ static int ak8975_remove(struct i2c_client *client) } static const struct i2c_device_id ak8975_id[] = { - {"ak8975", 0}, + {"ak8975", AK8975}, + {"ak8963", AK8963}, {} }; @@ -473,6 +618,7 @@ static struct i2c_driver ak8975_driver = { .driver = { .name = "ak8975", .of_match_table = ak8975_of_match, + .acpi_match_table = ACPI_PTR(ak_acpi_match), }, .probe = ak8975_probe, .remove = ak8975_remove, |