diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak8975.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak8975.c | 1121 |
1 files changed, 1121 insertions, 0 deletions
diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c new file mode 100644 index 000000000..3303feb54 --- /dev/null +++ b/drivers/iio/magnetometer/ak8975.c @@ -0,0 +1,1121 @@ +/* + * A sensor driver for the magnetometer AK8975. + * + * Magnetic compass sensor driver for monitoring magnetic flux information. + * + * Copyright (c) 2010, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include <linux/module.h> +#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/regulator/consumer.h> +#include <linux/pm_runtime.h> + +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include <linux/iio/magnetometer/ak8975.h> + +/* + * Register definitions, as well as various shifts and masks to get at the + * individual fields of the registers. + */ +#define AK8975_REG_WIA 0x00 +#define AK8975_DEVICE_ID 0x48 + +#define AK8975_REG_INFO 0x01 + +#define AK8975_REG_ST1 0x02 +#define AK8975_REG_ST1_DRDY_SHIFT 0 +#define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT) + +#define AK8975_REG_HXL 0x03 +#define AK8975_REG_HXH 0x04 +#define AK8975_REG_HYL 0x05 +#define AK8975_REG_HYH 0x06 +#define AK8975_REG_HZL 0x07 +#define AK8975_REG_HZH 0x08 +#define AK8975_REG_ST2 0x09 +#define AK8975_REG_ST2_DERR_SHIFT 2 +#define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT) + +#define AK8975_REG_ST2_HOFL_SHIFT 3 +#define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT) + +#define AK8975_REG_CNTL 0x0A +#define AK8975_REG_CNTL_MODE_SHIFT 0 +#define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT) +#define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00 +#define AK8975_REG_CNTL_MODE_ONCE 0x01 +#define AK8975_REG_CNTL_MODE_SELF_TEST 0x08 +#define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F + +#define AK8975_REG_RSVC 0x0B +#define AK8975_REG_ASTC 0x0C +#define AK8975_REG_TS1 0x0D +#define AK8975_REG_TS2 0x0E +#define AK8975_REG_I2CDIS 0x0F +#define AK8975_REG_ASAX 0x10 +#define AK8975_REG_ASAY 0x11 +#define AK8975_REG_ASAZ 0x12 + +#define AK8975_MAX_REGS AK8975_REG_ASAZ + +/* + * AK09912 Register definitions + */ +#define AK09912_REG_WIA1 0x00 +#define AK09912_REG_WIA2 0x01 +#define AK09912_DEVICE_ID 0x04 +#define AK09911_DEVICE_ID 0x05 + +#define AK09911_REG_INFO1 0x02 +#define AK09911_REG_INFO2 0x03 + +#define AK09912_REG_ST1 0x10 + +#define AK09912_REG_ST1_DRDY_SHIFT 0 +#define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT) + +#define AK09912_REG_HXL 0x11 +#define AK09912_REG_HXH 0x12 +#define AK09912_REG_HYL 0x13 +#define AK09912_REG_HYH 0x14 +#define AK09912_REG_HZL 0x15 +#define AK09912_REG_HZH 0x16 +#define AK09912_REG_TMPS 0x17 + +#define AK09912_REG_ST2 0x18 +#define AK09912_REG_ST2_HOFL_SHIFT 3 +#define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT) + +#define AK09912_REG_CNTL1 0x30 + +#define AK09912_REG_CNTL2 0x31 +#define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00 +#define AK09912_REG_CNTL_MODE_ONCE 0x01 +#define AK09912_REG_CNTL_MODE_SELF_TEST 0x10 +#define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F +#define AK09912_REG_CNTL2_MODE_SHIFT 0 +#define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT) + +#define AK09912_REG_CNTL3 0x32 + +#define AK09912_REG_TS1 0x33 +#define AK09912_REG_TS2 0x34 +#define AK09912_REG_TS3 0x35 +#define AK09912_REG_I2CDIS 0x36 +#define AK09912_REG_TS4 0x37 + +#define AK09912_REG_ASAX 0x60 +#define AK09912_REG_ASAY 0x61 +#define AK09912_REG_ASAZ 0x62 + +#define AK09912_MAX_REGS AK09912_REG_ASAZ + +/* + * Miscellaneous values. + */ +#define AK8975_MAX_CONVERSION_TIMEOUT 500 +#define AK8975_CONVERSION_DONE_POLL_TIME 10 +#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) + +/* + * Precalculate scale factor (in Gauss units) for each axis and + * store in the device data. + * + * This scale factor is axis-dependent, and is derived from 3 calibration + * factors ASA(x), ASA(y), and ASA(z). + * + * These ASA values are read from the sensor device at start of day, and + * cached in the device context struct. + * + * Adjusting the flux value with the sensitivity adjustment value should be + * done via the following formula: + * + * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 ) + * where H is the raw value, ASA is the sensitivity adjustment, and Hadj + * is the resultant adjusted value. + * + * We reduce the formula to: + * + * Hadj = H * (ASA + 128) / 256 + * + * H is in the range of -4096 to 4095. The magnetometer has a range of + * +-1229uT. To go from the raw value to uT is: + * + * HuT = H * 1229/4096, or roughly, 3/10. + * + * Since 1uT = 0.01 gauss, our final scale factor becomes: + * + * 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(). + * + * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we + * multiply the stored scale value by 1e6. + */ +static long ak8975_raw_to_gauss(u16 data) +{ + return (((long)data + 128) * 3000) / 256; +} + +/* + * For AK8963 and AK09911, same calculation, but the device is less sensitive: + * + * H is in the range of +-8190. The magnetometer has a range of + * +-4912uT. To go from the raw value to uT is: + * + * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10. + */ + +static long ak8963_09911_raw_to_gauss(u16 data) +{ + return (((long)data + 128) * 6000) / 256; +} + +/* + * For AK09912, same calculation, except the device is more sensitive: + * + * H is in the range of -32752 to 32752. The magnetometer has a range of + * +-4912uT. To go from the raw value to uT is: + * + * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10. + */ +static long ak09912_raw_to_gauss(u16 data) +{ + return (((long)data + 128) * 1500) / 256; +} + +/* Compatible Asahi Kasei Compass parts */ +enum asahi_compass_chipset { + AK8975, + AK8963, + AK09911, + AK09912, + AK_MAX_TYPE +}; + +enum ak_ctrl_reg_addr { + ST1, + ST2, + CNTL, + ASA_BASE, + MAX_REGS, + REGS_END, +}; + +enum ak_ctrl_reg_mask { + ST1_DRDY, + ST2_HOFL, + ST2_DERR, + CNTL_MODE, + MASK_END, +}; + +enum ak_ctrl_mode { + POWER_DOWN, + MODE_ONCE, + SELF_TEST, + FUSE_ROM, + MODE_END, +}; + +struct ak_def { + enum asahi_compass_chipset type; + long (*raw_to_gauss)(u16 data); + u16 range; + u8 ctrl_regs[REGS_END]; + u8 ctrl_masks[MASK_END]; + u8 ctrl_modes[MODE_END]; + u8 data_regs[3]; +}; + +static const struct ak_def ak_def_array[AK_MAX_TYPE] = { + { + .type = AK8975, + .raw_to_gauss = ak8975_raw_to_gauss, + .range = 4096, + .ctrl_regs = { + AK8975_REG_ST1, + AK8975_REG_ST2, + AK8975_REG_CNTL, + AK8975_REG_ASAX, + AK8975_MAX_REGS}, + .ctrl_masks = { + AK8975_REG_ST1_DRDY_MASK, + AK8975_REG_ST2_HOFL_MASK, + AK8975_REG_ST2_DERR_MASK, + AK8975_REG_CNTL_MODE_MASK}, + .ctrl_modes = { + AK8975_REG_CNTL_MODE_POWER_DOWN, + AK8975_REG_CNTL_MODE_ONCE, + AK8975_REG_CNTL_MODE_SELF_TEST, + AK8975_REG_CNTL_MODE_FUSE_ROM}, + .data_regs = { + AK8975_REG_HXL, + AK8975_REG_HYL, + AK8975_REG_HZL}, + }, + { + .type = AK8963, + .raw_to_gauss = ak8963_09911_raw_to_gauss, + .range = 8190, + .ctrl_regs = { + AK8975_REG_ST1, + AK8975_REG_ST2, + AK8975_REG_CNTL, + AK8975_REG_ASAX, + AK8975_MAX_REGS}, + .ctrl_masks = { + AK8975_REG_ST1_DRDY_MASK, + AK8975_REG_ST2_HOFL_MASK, + 0, + AK8975_REG_CNTL_MODE_MASK}, + .ctrl_modes = { + AK8975_REG_CNTL_MODE_POWER_DOWN, + AK8975_REG_CNTL_MODE_ONCE, + AK8975_REG_CNTL_MODE_SELF_TEST, + AK8975_REG_CNTL_MODE_FUSE_ROM}, + .data_regs = { + AK8975_REG_HXL, + AK8975_REG_HYL, + AK8975_REG_HZL}, + }, + { + .type = AK09911, + .raw_to_gauss = ak8963_09911_raw_to_gauss, + .range = 8192, + .ctrl_regs = { + AK09912_REG_ST1, + AK09912_REG_ST2, + AK09912_REG_CNTL2, + AK09912_REG_ASAX, + AK09912_MAX_REGS}, + .ctrl_masks = { + AK09912_REG_ST1_DRDY_MASK, + AK09912_REG_ST2_HOFL_MASK, + 0, + AK09912_REG_CNTL2_MODE_MASK}, + .ctrl_modes = { + AK09912_REG_CNTL_MODE_POWER_DOWN, + AK09912_REG_CNTL_MODE_ONCE, + AK09912_REG_CNTL_MODE_SELF_TEST, + AK09912_REG_CNTL_MODE_FUSE_ROM}, + .data_regs = { + AK09912_REG_HXL, + AK09912_REG_HYL, + AK09912_REG_HZL}, + }, + { + .type = AK09912, + .raw_to_gauss = ak09912_raw_to_gauss, + .range = 32752, + .ctrl_regs = { + AK09912_REG_ST1, + AK09912_REG_ST2, + AK09912_REG_CNTL2, + AK09912_REG_ASAX, + AK09912_MAX_REGS}, + .ctrl_masks = { + AK09912_REG_ST1_DRDY_MASK, + AK09912_REG_ST2_HOFL_MASK, + 0, + AK09912_REG_CNTL2_MODE_MASK}, + .ctrl_modes = { + AK09912_REG_CNTL_MODE_POWER_DOWN, + AK09912_REG_CNTL_MODE_ONCE, + AK09912_REG_CNTL_MODE_SELF_TEST, + AK09912_REG_CNTL_MODE_FUSE_ROM}, + .data_regs = { + AK09912_REG_HXL, + AK09912_REG_HYL, + AK09912_REG_HZL}, + } +}; + +/* + * Per-instance context data for the device. + */ +struct ak8975_data { + struct i2c_client *client; + const struct ak_def *def; + struct mutex lock; + u8 asa[3]; + long raw_to_gauss[3]; + int eoc_gpio; + int eoc_irq; + wait_queue_head_t data_ready_queue; + unsigned long flags; + u8 cntl_cache; + struct iio_mount_matrix orientation; + struct regulator *vdd; + struct regulator *vid; + + /* Ensure natural alignment of timestamp */ + struct { + s16 channels[3]; + s64 ts __aligned(8); + } scan; +}; + +/* Enable attached power regulator if any. */ +static int ak8975_power_on(const struct ak8975_data *data) +{ + int ret; + + ret = regulator_enable(data->vdd); + if (ret) { + dev_warn(&data->client->dev, + "Failed to enable specified Vdd supply\n"); + return ret; + } + ret = regulator_enable(data->vid); + if (ret) { + dev_warn(&data->client->dev, + "Failed to enable specified Vid supply\n"); + regulator_disable(data->vdd); + return ret; + } + /* + * According to the datasheet the power supply rise time i 200us + * and the minimum wait time before mode setting is 100us, in + * total 300 us. Add some margin and say minimum 500us here. + */ + usleep_range(500, 1000); + return 0; +} + +/* Disable attached power regulator if any. */ +static void ak8975_power_off(const struct ak8975_data *data) +{ + regulator_disable(data->vid); + regulator_disable(data->vdd); +} + +/* + * Return 0 if the i2c device is the one we expect. + * return a negative error number otherwise + */ +static int ak8975_who_i_am(struct i2c_client *client, + enum asahi_compass_chipset type) +{ + u8 wia_val[2]; + int ret; + + /* + * Signature for each device: + * Device | WIA1 | WIA2 + * AK09912 | DEVICE_ID | AK09912_DEVICE_ID + * AK09911 | DEVICE_ID | AK09911_DEVICE_ID + * AK8975 | DEVICE_ID | NA + * AK8963 | DEVICE_ID | NA + */ + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, AK09912_REG_WIA1, 2, wia_val); + if (ret < 0) { + dev_err(&client->dev, "Error reading WIA\n"); + return ret; + } + + if (wia_val[0] != AK8975_DEVICE_ID) + return -ENODEV; + + switch (type) { + case AK8975: + case AK8963: + return 0; + case AK09911: + if (wia_val[1] == AK09911_DEVICE_ID) + return 0; + break; + case AK09912: + if (wia_val[1] == AK09912_DEVICE_ID) + return 0; + break; + default: + dev_err(&client->dev, "Type %d unknown\n", type); + } + return -ENODEV; +} + +/* + * Helper function to write to CNTL register. + */ +static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode) +{ + u8 regval; + int ret; + + regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) | + data->def->ctrl_modes[mode]; + ret = i2c_smbus_write_byte_data(data->client, + data->def->ctrl_regs[CNTL], regval); + if (ret < 0) { + return ret; + } + data->cntl_cache = regval; + /* After mode change wait atleast 100us */ + usleep_range(100, 500); + + return 0; +} + +/* + * 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; + + init_waitqueue_head(&data->data_ready_queue); + clear_bit(0, &data->flags); + if (client->irq) + irq = client->irq; + else + irq = gpio_to_irq(data->eoc_gpio); + + rc = devm_request_irq(&client->dev, 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; + } + + data->eoc_irq = irq; + + return rc; +} + + +/* + * Perform some start-of-day setup, including reading the asa calibration + * values and caching them. + */ +static int ak8975_setup(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + int ret; + + /* Write the fused rom access mode. */ + ret = ak8975_set_mode(data, FUSE_ROM); + if (ret < 0) { + dev_err(&client->dev, "Error in setting fuse access mode\n"); + return ret; + } + + /* Get asa data and store in the device data. */ + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, data->def->ctrl_regs[ASA_BASE], + 3, data->asa); + if (ret < 0) { + dev_err(&client->dev, "Not able to read asa data\n"); + return ret; + } + + /* After reading fuse ROM data set power-down mode */ + ret = ak8975_set_mode(data, POWER_DOWN); + if (ret < 0) { + dev_err(&client->dev, "Error in setting power-down mode\n"); + return ret; + } + + if (data->eoc_gpio > 0 || client->irq > 0) { + ret = ak8975_setup_irq(data); + if (ret < 0) { + dev_err(&client->dev, + "Error setting data ready interrupt\n"); + return ret; + } + } + + data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]); + data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]); + data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]); + + return 0; +} + +static int wait_conversion_complete_gpio(struct ak8975_data *data) +{ + struct i2c_client *client = data->client; + u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; + int ret; + + /* Wait for the conversion to complete. */ + while (timeout_ms) { + msleep(AK8975_CONVERSION_DONE_POLL_TIME); + if (gpio_get_value(data->eoc_gpio)) + break; + timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; + } + if (!timeout_ms) { + dev_err(&client->dev, "Conversion timeout happened\n"); + return -EINVAL; + } + + ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]); + if (ret < 0) + dev_err(&client->dev, "Error in reading ST1\n"); + + return ret; +} + +static int wait_conversion_complete_polled(struct ak8975_data *data) +{ + struct i2c_client *client = data->client; + u8 read_status; + u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT; + int ret; + + /* Wait for the conversion to complete. */ + while (timeout_ms) { + msleep(AK8975_CONVERSION_DONE_POLL_TIME); + ret = i2c_smbus_read_byte_data(client, + data->def->ctrl_regs[ST1]); + if (ret < 0) { + dev_err(&client->dev, "Error in reading ST1\n"); + return ret; + } + read_status = ret; + if (read_status) + break; + timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME; + } + if (!timeout_ms) { + 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; +} + +static int ak8975_start_read_axis(struct ak8975_data *data, + const struct i2c_client *client) +{ + /* Set up the device for taking a sample. */ + int ret = ak8975_set_mode(data, MODE_ONCE); + + if (ret < 0) { + dev_err(&client->dev, "Error in setting operating mode\n"); + return ret; + } + + /* Wait for the conversion to complete. */ + 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) + return ret; + + /* This will be executed only for non-interrupt based waiting case */ + if (ret & data->def->ctrl_masks[ST1_DRDY]) { + ret = i2c_smbus_read_byte_data(client, + data->def->ctrl_regs[ST2]); + if (ret < 0) { + dev_err(&client->dev, "Error in reading ST2\n"); + return ret; + } + if (ret & (data->def->ctrl_masks[ST2_DERR] | + data->def->ctrl_masks[ST2_HOFL])) { + dev_err(&client->dev, "ST2 status error 0x%x\n", ret); + return -EINVAL; + } + } + + return 0; +} + +/* Retrieve raw flux value for one of the x, y, or z axis. */ +static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val) +{ + struct ak8975_data *data = iio_priv(indio_dev); + const struct i2c_client *client = data->client; + const struct ak_def *def = data->def; + __le16 rval; + u16 buff; + int ret; + + pm_runtime_get_sync(&data->client->dev); + + mutex_lock(&data->lock); + + ret = ak8975_start_read_axis(data, client); + if (ret) + goto exit; + + ret = i2c_smbus_read_i2c_block_data_or_emulated( + client, def->data_regs[index], + sizeof(rval), (u8*)&rval); + if (ret < 0) + goto exit; + + mutex_unlock(&data->lock); + + pm_runtime_mark_last_busy(&data->client->dev); + pm_runtime_put_autosuspend(&data->client->dev); + + /* Swap bytes and convert to valid range. */ + buff = le16_to_cpu(rval); + *val = clamp_t(s16, buff, -def->range, def->range); + return IIO_VAL_INT; + +exit: + mutex_unlock(&data->lock); + dev_err(&client->dev, "Error in reading axis\n"); + return ret; +} + +static int ak8975_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, + long mask) +{ + struct ak8975_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return ak8975_read_axis(indio_dev, chan->address, val); + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = data->raw_to_gauss[chan->address]; + return IIO_VAL_INT_PLUS_MICRO; + } + return -EINVAL; +} + +static const struct iio_mount_matrix * +ak8975_get_mount_matrix(const struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + return &((struct ak8975_data *)iio_priv(indio_dev))->orientation; +} + +static const struct iio_chan_spec_ext_info ak8975_ext_info[] = { + IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix), + { }, +}; + +#define AK8975_CHANNEL(axis, index) \ + { \ + .type = IIO_MAGN, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .address = index, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_CPU \ + }, \ + .ext_info = ak8975_ext_info, \ + } + +static const struct iio_chan_spec ak8975_channels[] = { + AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +static const unsigned long ak8975_scan_masks[] = { 0x7, 0 }; + +static const struct iio_info ak8975_info = { + .read_raw = &ak8975_read_raw, +}; + +#ifdef CONFIG_ACPI +static const struct acpi_device_id ak_acpi_match[] = { + {"AK8975", AK8975}, + {"AK8963", AK8963}, + {"INVN6500", AK8963}, + {"AK009911", AK09911}, + {"AK09911", AK09911}, + {"AK09912", AK09912}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, ak_acpi_match); +#endif + +static const 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 dev_name(dev); +} + +static void ak8975_fill_buffer(struct iio_dev *indio_dev) +{ + struct ak8975_data *data = iio_priv(indio_dev); + const struct i2c_client *client = data->client; + const struct ak_def *def = data->def; + int ret; + __le16 fval[3]; + + mutex_lock(&data->lock); + + ret = ak8975_start_read_axis(data, client); + if (ret) + goto unlock; + + /* + * For each axis, read the flux value from the appropriate register + * (the register is specified in the iio device attributes). + */ + ret = i2c_smbus_read_i2c_block_data_or_emulated(client, + def->data_regs[0], + 3 * sizeof(fval[0]), + (u8 *)fval); + if (ret < 0) + goto unlock; + + mutex_unlock(&data->lock); + + /* Clamp to valid range. */ + data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range); + data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range); + data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range); + + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + iio_get_time_ns(indio_dev)); + + return; + +unlock: + mutex_unlock(&data->lock); + dev_err(&client->dev, "Error in reading axes block\n"); +} + +static irqreturn_t ak8975_handle_trigger(int irq, void *p) +{ + const struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + + ak8975_fill_buffer(indio_dev); + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +static int ak8975_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ak8975_data *data; + struct iio_dev *indio_dev; + int eoc_gpio; + int err; + const char *name = NULL; + enum asahi_compass_chipset chipset = AK_MAX_TYPE; + const struct ak8975_platform_data *pdata = + dev_get_platdata(&client->dev); + + /* Grab and set up the supplied GPIO. */ + if (pdata) + eoc_gpio = pdata->eoc_gpio; + 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 */ + if (gpio_is_valid(eoc_gpio)) { + err = devm_gpio_request_one(&client->dev, eoc_gpio, + GPIOF_IN, "ak_8975"); + if (err < 0) { + dev_err(&client->dev, + "failed to request GPIO %d, error %d\n", + eoc_gpio, err); + return err; + } + } + + /* Register with IIO */ + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (indio_dev == NULL) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + + data->client = client; + data->eoc_gpio = eoc_gpio; + data->eoc_irq = 0; + + if (!pdata) { + err = of_iio_read_mount_matrix(&client->dev, + "mount-matrix", + &data->orientation); + if (err) + return err; + } else + data->orientation = pdata->orientation; + + /* id will be NULL when enumerated via ACPI */ + if (id) { + chipset = (enum asahi_compass_chipset)(id->driver_data); + name = id->name; + } else if (ACPI_HANDLE(&client->dev)) { + name = ak8975_match_acpi_device(&client->dev, &chipset); + if (!name) + return -ENODEV; + } else + return -ENOSYS; + + if (chipset >= AK_MAX_TYPE) { + dev_err(&client->dev, "AKM device type unsupported: %d\n", + chipset); + return -ENODEV; + } + + data->def = &ak_def_array[chipset]; + + /* Fetch the regulators */ + data->vdd = devm_regulator_get(&client->dev, "vdd"); + if (IS_ERR(data->vdd)) + return PTR_ERR(data->vdd); + data->vid = devm_regulator_get(&client->dev, "vid"); + if (IS_ERR(data->vid)) + return PTR_ERR(data->vid); + + err = ak8975_power_on(data); + if (err) + return err; + + err = ak8975_who_i_am(client, data->def->type); + if (err < 0) { + dev_err(&client->dev, "Unexpected device\n"); + goto power_off; + } + 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) { + dev_err(&client->dev, "%s initialization fails\n", name); + goto power_off; + } + + mutex_init(&data->lock); + indio_dev->dev.parent = &client->dev; + indio_dev->channels = ak8975_channels; + indio_dev->num_channels = ARRAY_SIZE(ak8975_channels); + indio_dev->info = &ak8975_info; + indio_dev->available_scan_masks = ak8975_scan_masks; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = name; + + err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger, + NULL); + if (err) { + dev_err(&client->dev, "triggered buffer setup failed\n"); + goto power_off; + } + + err = iio_device_register(indio_dev); + if (err) { + dev_err(&client->dev, "device register failed\n"); + goto cleanup_buffer; + } + + /* Enable runtime PM */ + pm_runtime_get_noresume(&client->dev); + pm_runtime_set_active(&client->dev); + pm_runtime_enable(&client->dev); + /* + * The device comes online in 500us, so add two orders of magnitude + * of delay before autosuspending: 50 ms. + */ + pm_runtime_set_autosuspend_delay(&client->dev, 50); + pm_runtime_use_autosuspend(&client->dev); + pm_runtime_put(&client->dev); + + return 0; + +cleanup_buffer: + iio_triggered_buffer_cleanup(indio_dev); +power_off: + ak8975_power_off(data); + return err; +} + +static int ak8975_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + + pm_runtime_get_sync(&client->dev); + pm_runtime_put_noidle(&client->dev); + pm_runtime_disable(&client->dev); + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + ak8975_set_mode(data, POWER_DOWN); + ak8975_power_off(data); + + return 0; +} + +#ifdef CONFIG_PM +static int ak8975_runtime_suspend(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + int ret; + + /* Set the device in power down if it wasn't already */ + ret = ak8975_set_mode(data, POWER_DOWN); + if (ret < 0) { + dev_err(&client->dev, "Error in setting power-down mode\n"); + return ret; + } + /* Next cut the regulators */ + ak8975_power_off(data); + + return 0; +} + +static int ak8975_runtime_resume(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak8975_data *data = iio_priv(indio_dev); + int ret; + + /* Take up the regulators */ + ak8975_power_on(data); + /* + * We come up in powered down mode, the reading routines will + * put us in the mode to read values later. + */ + ret = ak8975_set_mode(data, POWER_DOWN); + if (ret < 0) { + dev_err(&client->dev, "Error in setting power-down mode\n"); + return ret; + } + + return 0; +} +#endif /* CONFIG_PM */ + +static const struct dev_pm_ops ak8975_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(ak8975_runtime_suspend, + ak8975_runtime_resume, NULL) +}; + +static const struct i2c_device_id ak8975_id[] = { + {"ak8975", AK8975}, + {"ak8963", AK8963}, + {"AK8963", AK8963}, + {"ak09911", AK09911}, + {"ak09912", AK09912}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, ak8975_id); + +static const struct of_device_id ak8975_of_match[] = { + { .compatible = "asahi-kasei,ak8975", }, + { .compatible = "ak8975", }, + { .compatible = "asahi-kasei,ak8963", }, + { .compatible = "ak8963", }, + { .compatible = "asahi-kasei,ak09911", }, + { .compatible = "ak09911", }, + { .compatible = "asahi-kasei,ak09912", }, + { .compatible = "ak09912", }, + {} +}; +MODULE_DEVICE_TABLE(of, ak8975_of_match); + +static struct i2c_driver ak8975_driver = { + .driver = { + .name = "ak8975", + .pm = &ak8975_dev_pm_ops, + .of_match_table = of_match_ptr(ak8975_of_match), + .acpi_match_table = ACPI_PTR(ak_acpi_match), + }, + .probe = ak8975_probe, + .remove = ak8975_remove, + .id_table = ak8975_id, +}; +module_i2c_driver(ak8975_driver); + +MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); +MODULE_DESCRIPTION("AK8975 magnetometer driver"); +MODULE_LICENSE("GPL"); |