--- /dev/null
+/*
+ * 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/iio/iio.h>
+#include <linux/iio/sysfs.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 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;
+ struct ak_def *def;
+ struct attribute_group attrs;
+ 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;
+};
+
+/*
+ * 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(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;
+
+ 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;
+ }
+
+ 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.
+ */
+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(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;
+}
+
+/*
+ * Emits the raw flux value for 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);
+ struct i2c_client *client = data->client;
+ int ret;
+
+ mutex_lock(&data->lock);
+
+ /* Set up the device for taking a sample. */
+ ret = ak8975_set_mode(data, MODE_ONCE);
+ if (ret < 0) {
+ dev_err(&client->dev, "Error in setting operating mode\n");
+ goto exit;
+ }
+
+ /* 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)
+ goto exit;
+
+ /* 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");
+ goto exit;
+ }
+ 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);
+ ret = -EINVAL;
+ goto exit;
+ }
+ }
+
+ /* Read the flux value from the appropriate register
+ (the register is specified in the iio device attributes). */
+ ret = i2c_smbus_read_word_data(client, data->def->data_regs[index]);
+ if (ret < 0) {
+ dev_err(&client->dev, "Read axis data fails\n");
+ goto exit;
+ }
+
+ mutex_unlock(&data->lock);
+
+ /* Clamp to valid range. */
+ *val = clamp_t(s16, ret, -data->def->range, data->def->range);
+ return IIO_VAL_INT;
+
+exit:
+ mutex_unlock(&data->lock);
+ 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;
+}
+
+#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, \
+ }
+
+static const struct iio_chan_spec ak8975_channels[] = {
+ AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
+};
+
+static const struct iio_info ak8975_info = {
+ .read_raw = &ak8975_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static const struct acpi_device_id ak_acpi_match[] = {
+ {"AK8975", AK8975},
+ {"AK8963", AK8963},
+ {"INVN6500", AK8963},
+ {"AK09911", AK09911},
+ {"AK09912", AK09912},
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
+
+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 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;
+
+ /* Grab and set up the supplied GPIO. */
+ 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 */
+ 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;
+
+ /* 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);
+ 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];
+ err = ak8975_who_i_am(client, data->def->type);
+ if (err < 0) {
+ dev_err(&client->dev, "Unexpected device\n");
+ return err;
+ }
+ 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);
+ return err;
+ }
+
+ 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->modes = INDIO_DIRECT_MODE;
+ indio_dev->name = name;
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+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",
+ .of_match_table = of_match_ptr(ak8975_of_match),
+ .acpi_match_table = ACPI_PTR(ak_acpi_match),
+ },
+ .probe = ak8975_probe,
+ .id_table = ak8975_id,
+};
+module_i2c_driver(ak8975_driver);
+
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_DESCRIPTION("AK8975 magnetometer driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff