diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak8974.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak8974.c | 1058 |
1 files changed, 1058 insertions, 0 deletions
diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c new file mode 100644 index 0000000000..c74d11943e --- /dev/null +++ b/drivers/iio/magnetometer/ak8974.c @@ -0,0 +1,1058 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for the Asahi Kasei EMD Corporation AK8974 + * and Aichi Steel AMI305 magnetometer chips. + * Based on a patch from Samu Onkalo and the AK8975 IIO driver. + * + * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). + * Copyright (c) 2010 NVIDIA Corporation. + * Copyright (C) 2016 Linaro Ltd. + * + * Author: Samu Onkalo <samu.p.onkalo@nokia.com> + * Author: Linus Walleij <linus.walleij@linaro.org> + */ +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/kernel.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/irq.h> /* For irq_get_irq_data() */ +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/bitops.h> +#include <linux/random.h> +#include <linux/regmap.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> + +/* + * 16-bit registers are little-endian. LSB is at the address defined below + * and MSB is at the next higher address. + */ + +/* These registers are common for AK8974 and AMI30x */ +#define AK8974_SELFTEST 0x0C +#define AK8974_SELFTEST_IDLE 0x55 +#define AK8974_SELFTEST_OK 0xAA + +#define AK8974_INFO 0x0D + +#define AK8974_WHOAMI 0x0F +#define AK8974_WHOAMI_VALUE_AMI306 0x46 +#define AK8974_WHOAMI_VALUE_AMI305 0x47 +#define AK8974_WHOAMI_VALUE_AK8974 0x48 +#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49 + +#define AK8974_DATA_X 0x10 +#define AK8974_DATA_Y 0x12 +#define AK8974_DATA_Z 0x14 +#define AK8974_INT_SRC 0x16 +#define AK8974_STATUS 0x18 +#define AK8974_INT_CLEAR 0x1A +#define AK8974_CTRL1 0x1B +#define AK8974_CTRL2 0x1C +#define AK8974_CTRL3 0x1D +#define AK8974_INT_CTRL 0x1E +#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */ +#define AK8974_PRESET 0x30 + +/* AK8974-specific offsets */ +#define AK8974_OFFSET_X 0x20 +#define AK8974_OFFSET_Y 0x22 +#define AK8974_OFFSET_Z 0x24 +/* AMI305-specific offsets */ +#define AMI305_OFFSET_X 0x6C +#define AMI305_OFFSET_Y 0x72 +#define AMI305_OFFSET_Z 0x78 + +/* Different temperature registers */ +#define AK8974_TEMP 0x31 +#define AMI305_TEMP 0x60 + +/* AMI306-specific control register */ +#define AMI306_CTRL4 0x5C + +/* AMI306 factory calibration data */ + +/* fine axis sensitivity */ +#define AMI306_FINEOUTPUT_X 0x90 +#define AMI306_FINEOUTPUT_Y 0x92 +#define AMI306_FINEOUTPUT_Z 0x94 + +/* axis sensitivity */ +#define AMI306_SENS_X 0x96 +#define AMI306_SENS_Y 0x98 +#define AMI306_SENS_Z 0x9A + +/* axis cross-interference */ +#define AMI306_GAIN_PARA_XZ 0x9C +#define AMI306_GAIN_PARA_XY 0x9D +#define AMI306_GAIN_PARA_YZ 0x9E +#define AMI306_GAIN_PARA_YX 0x9F +#define AMI306_GAIN_PARA_ZY 0xA0 +#define AMI306_GAIN_PARA_ZX 0xA1 + +/* offset at ZERO magnetic field */ +#define AMI306_OFFZERO_X 0xF8 +#define AMI306_OFFZERO_Y 0xFA +#define AMI306_OFFZERO_Z 0xFC + + +#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */ +#define AK8974_INT_Y_HIGH BIT(6) +#define AK8974_INT_Z_HIGH BIT(5) +#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */ +#define AK8974_INT_Y_LOW BIT(3) +#define AK8974_INT_Z_LOW BIT(2) +#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */ + +#define AK8974_STATUS_DRDY BIT(6) /* Data ready */ +#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */ +#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */ + +#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */ +#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */ +#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */ +#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */ + +#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */ +#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */ +#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */ +#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL) + +#define AK8974_CTRL3_RESET BIT(7) /* Software reset */ +#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */ +#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */ +#define AK8974_CTRL3_RESDEF 0x00 + +#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */ +#define AK8974_INT_CTRL_YEN BIT(6) +#define AK8974_INT_CTRL_ZEN BIT(5) +#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5)) +#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */ +#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */ +#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL) + +/* HSCDTD008A-specific control register */ +#define HSCDTD008A_CTRL4 0x1E +#define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */ +#define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */ +#define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE) + +/* The AMI305 has elaborate FW version and serial number registers */ +#define AMI305_VER 0xE8 +#define AMI305_SN 0xEA + +#define AK8974_MAX_RANGE 2048 + +#define AK8974_POWERON_DELAY 50 +#define AK8974_ACTIVATE_DELAY 1 +#define AK8974_SELFTEST_DELAY 1 +/* + * Set the autosuspend to two orders of magnitude larger than the poweron + * delay to make sane reasonable power tradeoff savings (5 seconds in + * this case). + */ +#define AK8974_AUTOSUSPEND_DELAY 5000 + +#define AK8974_MEASTIME 3 + +#define AK8974_PWR_ON 1 +#define AK8974_PWR_OFF 0 + +/** + * struct ak8974 - state container for the AK8974 driver + * @i2c: parent I2C client + * @orientation: mounting matrix, flipped axis etc + * @map: regmap to access the AK8974 registers over I2C + * @regs: the avdd and dvdd power regulators + * @name: the name of the part + * @variant: the whoami ID value (for selecting code paths) + * @lock: locks the magnetometer for exclusive use during a measurement + * @drdy_irq: uses the DRDY IRQ line + * @drdy_complete: completion for DRDY + * @drdy_active_low: the DRDY IRQ is active low + * @scan: timestamps + */ +struct ak8974 { + struct i2c_client *i2c; + struct iio_mount_matrix orientation; + struct regmap *map; + struct regulator_bulk_data regs[2]; + const char *name; + u8 variant; + struct mutex lock; + bool drdy_irq; + struct completion drdy_complete; + bool drdy_active_low; + /* Ensure timestamp is naturally aligned */ + struct { + __le16 channels[3]; + s64 ts __aligned(8); + } scan; +}; + +static const char ak8974_reg_avdd[] = "avdd"; +static const char ak8974_reg_dvdd[] = "dvdd"; + +static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val) +{ + int ret; + __le16 bulk; + + ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2); + if (ret) + return ret; + *val = le16_to_cpu(bulk); + + return 0; +} + +static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val) +{ + __le16 bulk = cpu_to_le16(val); + + return regmap_bulk_write(ak8974->map, reg, &bulk, 2); +} + +static int ak8974_set_power(struct ak8974 *ak8974, bool mode) +{ + int ret; + u8 val; + + val = mode ? AK8974_CTRL1_POWER : 0; + val |= AK8974_CTRL1_FORCE_EN; + ret = regmap_write(ak8974->map, AK8974_CTRL1, val); + if (ret < 0) + return ret; + + if (mode) + msleep(AK8974_ACTIVATE_DELAY); + + return 0; +} + +static int ak8974_reset(struct ak8974 *ak8974) +{ + int ret; + + /* Power on to get register access. Sets CTRL1 reg to reset state */ + ret = ak8974_set_power(ak8974, AK8974_PWR_ON); + if (ret) + return ret; + ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF); + if (ret) + return ret; + ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF); + if (ret) + return ret; + if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) { + ret = regmap_write(ak8974->map, AK8974_INT_CTRL, + AK8974_INT_CTRL_RESDEF); + if (ret) + return ret; + } else { + ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4, + HSCDTD008A_CTRL4_RESDEF); + if (ret) + return ret; + } + + /* After reset, power off is default state */ + return ak8974_set_power(ak8974, AK8974_PWR_OFF); +} + +static int ak8974_configure(struct ak8974 *ak8974) +{ + int ret; + + ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN | + AK8974_CTRL2_INT_EN); + if (ret) + return ret; + ret = regmap_write(ak8974->map, AK8974_CTRL3, 0); + if (ret) + return ret; + if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) { + /* magic from datasheet: set high-speed measurement mode */ + ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E); + if (ret) + return ret; + } + if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A) + return 0; + ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL); + if (ret) + return ret; + + return regmap_write(ak8974->map, AK8974_PRESET, 0); +} + +static int ak8974_trigmeas(struct ak8974 *ak8974) +{ + unsigned int clear; + u8 mask; + u8 val; + int ret; + + /* Clear any previous measurement overflow status */ + ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear); + if (ret) + return ret; + + /* If we have a DRDY IRQ line, use it */ + if (ak8974->drdy_irq) { + mask = AK8974_CTRL2_INT_EN | + AK8974_CTRL2_DRDY_EN | + AK8974_CTRL2_DRDY_POL; + val = AK8974_CTRL2_DRDY_EN; + + if (!ak8974->drdy_active_low) + val |= AK8974_CTRL2_DRDY_POL; + + init_completion(&ak8974->drdy_complete); + ret = regmap_update_bits(ak8974->map, AK8974_CTRL2, + mask, val); + if (ret) + return ret; + } + + /* Force a measurement */ + return regmap_update_bits(ak8974->map, + AK8974_CTRL3, + AK8974_CTRL3_FORCE, + AK8974_CTRL3_FORCE); +} + +static int ak8974_await_drdy(struct ak8974 *ak8974) +{ + int timeout = 2; + unsigned int val; + int ret; + + if (ak8974->drdy_irq) { + ret = wait_for_completion_timeout(&ak8974->drdy_complete, + 1 + msecs_to_jiffies(1000)); + if (!ret) { + dev_err(&ak8974->i2c->dev, + "timeout waiting for DRDY IRQ\n"); + return -ETIMEDOUT; + } + return 0; + } + + /* Default delay-based poll loop */ + do { + msleep(AK8974_MEASTIME); + ret = regmap_read(ak8974->map, AK8974_STATUS, &val); + if (ret < 0) + return ret; + if (val & AK8974_STATUS_DRDY) + return 0; + } while (--timeout); + + dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n"); + return -ETIMEDOUT; +} + +static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result) +{ + unsigned int src; + int ret; + + ret = ak8974_await_drdy(ak8974); + if (ret) + return ret; + ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src); + if (ret < 0) + return ret; + + /* Out of range overflow! Strong magnet close? */ + if (src & AK8974_INT_RANGE) { + dev_err(&ak8974->i2c->dev, + "range overflow in sensor\n"); + return -ERANGE; + } + + ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6); + if (ret) + return ret; + + return ret; +} + +static irqreturn_t ak8974_drdy_irq(int irq, void *d) +{ + struct ak8974 *ak8974 = d; + + if (!ak8974->drdy_irq) + return IRQ_NONE; + + /* TODO: timestamp here to get good measurement stamps */ + return IRQ_WAKE_THREAD; +} + +static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d) +{ + struct ak8974 *ak8974 = d; + unsigned int val; + int ret; + + /* Check if this was a DRDY from us */ + ret = regmap_read(ak8974->map, AK8974_STATUS, &val); + if (ret < 0) { + dev_err(&ak8974->i2c->dev, "error reading DRDY status\n"); + return IRQ_HANDLED; + } + if (val & AK8974_STATUS_DRDY) { + /* Yes this was our IRQ */ + complete(&ak8974->drdy_complete); + return IRQ_HANDLED; + } + + /* We may be on a shared IRQ, let the next client check */ + return IRQ_NONE; +} + +static int ak8974_selftest(struct ak8974 *ak8974) +{ + struct device *dev = &ak8974->i2c->dev; + unsigned int val; + int ret; + + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); + if (ret) + return ret; + if (val != AK8974_SELFTEST_IDLE) { + dev_err(dev, "selftest not idle before test\n"); + return -EIO; + } + + /* Trigger self-test */ + ret = regmap_update_bits(ak8974->map, + AK8974_CTRL3, + AK8974_CTRL3_SELFTEST, + AK8974_CTRL3_SELFTEST); + if (ret) { + dev_err(dev, "could not write CTRL3\n"); + return ret; + } + + msleep(AK8974_SELFTEST_DELAY); + + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); + if (ret) + return ret; + if (val != AK8974_SELFTEST_OK) { + dev_err(dev, "selftest result NOT OK (%02x)\n", val); + return -EIO; + } + + ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val); + if (ret) + return ret; + if (val != AK8974_SELFTEST_IDLE) { + dev_err(dev, "selftest not idle after test (%02x)\n", val); + return -EIO; + } + dev_dbg(dev, "passed self-test\n"); + + return 0; +} + +static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg, + __le16 *tab, size_t tab_size) +{ + int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size); + if (ret) { + memset(tab, 0xFF, tab_size); + dev_warn(&ak8974->i2c->dev, + "can't read calibration data (regs %u..%zu): %d\n", + reg, reg + tab_size - 1, ret); + } else { + add_device_randomness(tab, tab_size); + } +} + +static int ak8974_detect(struct ak8974 *ak8974) +{ + unsigned int whoami; + const char *name; + int ret; + unsigned int fw; + u16 sn; + + ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami); + if (ret) + return ret; + + name = "ami305"; + + switch (whoami) { + case AK8974_WHOAMI_VALUE_AMI306: + name = "ami306"; + fallthrough; + case AK8974_WHOAMI_VALUE_AMI305: + ret = regmap_read(ak8974->map, AMI305_VER, &fw); + if (ret) + return ret; + fw &= 0x7f; /* only bits 0 thru 6 valid */ + ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn); + if (ret) + return ret; + add_device_randomness(&sn, sizeof(sn)); + dev_info(&ak8974->i2c->dev, + "detected %s, FW ver %02x, S/N: %04x\n", + name, fw, sn); + break; + case AK8974_WHOAMI_VALUE_AK8974: + name = "ak8974"; + dev_info(&ak8974->i2c->dev, "detected AK8974\n"); + break; + case AK8974_WHOAMI_VALUE_HSCDTD008A: + name = "hscdtd008a"; + dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n"); + break; + default: + dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ", + whoami); + return -ENODEV; + } + + ak8974->name = name; + ak8974->variant = whoami; + + if (whoami == AK8974_WHOAMI_VALUE_AMI306) { + __le16 fab_data1[9], fab_data2[3]; + int i; + + ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X, + fab_data1, sizeof(fab_data1)); + ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X, + fab_data2, sizeof(fab_data2)); + + for (i = 0; i < 3; ++i) { + static const char axis[3] = "XYZ"; + static const char pgaxis[6] = "ZYZXYX"; + unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F; + unsigned fine = le16_to_cpu(fab_data1[i]); + unsigned sens = le16_to_cpu(fab_data1[i + 3]); + unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]); + unsigned pgain2 = pgain1 >> 8; + + pgain1 &= 0xFF; + + dev_info(&ak8974->i2c->dev, + "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n", + axis[i], offz, sens, fine, pgaxis[i * 2], + pgain1, pgaxis[i * 2 + 1], pgain2); + } + } + + return 0; +} + +static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address, + int *val) +{ + __le16 hw_values[3]; + int ret; + + pm_runtime_get_sync(&ak8974->i2c->dev); + mutex_lock(&ak8974->lock); + + /* + * We read all axes and discard all but one, for optimized + * reading, use the triggered buffer. + */ + ret = ak8974_trigmeas(ak8974); + if (ret) + goto out_unlock; + ret = ak8974_getresult(ak8974, hw_values); + if (ret) + goto out_unlock; + /* + * This explicit cast to (s16) is necessary as the measurement + * is done in 2's complement with positive and negative values. + * The follwing assignment to *val will then convert the signed + * s16 value to a signed int value. + */ + *val = (s16)le16_to_cpu(hw_values[address]); +out_unlock: + mutex_unlock(&ak8974->lock); + pm_runtime_mark_last_busy(&ak8974->i2c->dev); + pm_runtime_put_autosuspend(&ak8974->i2c->dev); + + return ret; +} + +static int ak8974_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, + long mask) +{ + struct ak8974 *ak8974 = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + if (chan->address > 2) { + dev_err(&ak8974->i2c->dev, "faulty channel address\n"); + return -EIO; + } + ret = ak8974_measure_channel(ak8974, chan->address, val); + if (ret) + return ret; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + switch (ak8974->variant) { + case AK8974_WHOAMI_VALUE_AMI306: + case AK8974_WHOAMI_VALUE_AMI305: + /* + * The datasheet for AMI305 and AMI306, page 6 + * specifies the range of the sensor to be + * +/- 12 Gauss. + */ + *val = 12; + /* + * 12 bits are used, +/- 2^11 + * [ -2048 .. 2047 ] (manual page 20) + * [ 0xf800 .. 0x07ff ] + */ + *val2 = 11; + return IIO_VAL_FRACTIONAL_LOG2; + case AK8974_WHOAMI_VALUE_HSCDTD008A: + /* + * The datasheet for HSCDTF008A, page 3 specifies the + * range of the sensor as +/- 2.4 mT per axis, which + * corresponds to +/- 2400 uT = +/- 24 Gauss. + */ + *val = 24; + /* + * 15 bits are used (set up in CTRL4), +/- 2^14 + * [ -16384 .. 16383 ] (manual page 24) + * [ 0xc000 .. 0x3fff ] + */ + *val2 = 14; + return IIO_VAL_FRACTIONAL_LOG2; + default: + /* GUESSING +/- 12 Gauss */ + *val = 12; + /* GUESSING 12 bits ADC +/- 2^11 */ + *val2 = 11; + return IIO_VAL_FRACTIONAL_LOG2; + } + break; + default: + /* Unknown request */ + break; + } + + return -EINVAL; +} + +static void ak8974_fill_buffer(struct iio_dev *indio_dev) +{ + struct ak8974 *ak8974 = iio_priv(indio_dev); + int ret; + + pm_runtime_get_sync(&ak8974->i2c->dev); + mutex_lock(&ak8974->lock); + + ret = ak8974_trigmeas(ak8974); + if (ret) { + dev_err(&ak8974->i2c->dev, "error triggering measure\n"); + goto out_unlock; + } + ret = ak8974_getresult(ak8974, ak8974->scan.channels); + if (ret) { + dev_err(&ak8974->i2c->dev, "error getting measures\n"); + goto out_unlock; + } + + iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan, + iio_get_time_ns(indio_dev)); + + out_unlock: + mutex_unlock(&ak8974->lock); + pm_runtime_mark_last_busy(&ak8974->i2c->dev); + pm_runtime_put_autosuspend(&ak8974->i2c->dev); +} + +static irqreturn_t ak8974_handle_trigger(int irq, void *p) +{ + const struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + + ak8974_fill_buffer(indio_dev); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +static const struct iio_mount_matrix * +ak8974_get_mount_matrix(const struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct ak8974 *ak8974 = iio_priv(indio_dev); + + return &ak8974->orientation; +} + +static const struct iio_chan_spec_ext_info ak8974_ext_info[] = { + IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix), + { }, +}; + +#define AK8974_AXIS_CHANNEL(axis, index, bits) \ + { \ + .type = IIO_MAGN, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .ext_info = ak8974_ext_info, \ + .address = index, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = bits, \ + .storagebits = 16, \ + .endianness = IIO_LE \ + }, \ + } + +/* + * We have no datasheet for the AK8974 but we guess that its + * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit + * ADC. + */ +static const struct iio_chan_spec ak8974_12_bits_channels[] = { + AK8974_AXIS_CHANNEL(X, 0, 12), + AK8974_AXIS_CHANNEL(Y, 1, 12), + AK8974_AXIS_CHANNEL(Z, 2, 12), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +/* + * The HSCDTD008A has 15 bits resolution the way we set it up + * in CTRL4. + */ +static const struct iio_chan_spec ak8974_15_bits_channels[] = { + AK8974_AXIS_CHANNEL(X, 0, 15), + AK8974_AXIS_CHANNEL(Y, 1, 15), + AK8974_AXIS_CHANNEL(Z, 2, 15), + IIO_CHAN_SOFT_TIMESTAMP(3), +}; + +static const unsigned long ak8974_scan_masks[] = { 0x7, 0 }; + +static const struct iio_info ak8974_info = { + .read_raw = &ak8974_read_raw, +}; + +static bool ak8974_writeable_reg(struct device *dev, unsigned int reg) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct iio_dev *indio_dev = i2c_get_clientdata(i2c); + struct ak8974 *ak8974 = iio_priv(indio_dev); + + switch (reg) { + case AK8974_CTRL1: + case AK8974_CTRL2: + case AK8974_CTRL3: + case AK8974_INT_CTRL: + case AK8974_INT_THRES: + case AK8974_INT_THRES + 1: + return true; + case AK8974_PRESET: + case AK8974_PRESET + 1: + return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A; + case AK8974_OFFSET_X: + case AK8974_OFFSET_X + 1: + case AK8974_OFFSET_Y: + case AK8974_OFFSET_Y + 1: + case AK8974_OFFSET_Z: + case AK8974_OFFSET_Z + 1: + return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 || + ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A; + case AMI305_OFFSET_X: + case AMI305_OFFSET_X + 1: + case AMI305_OFFSET_Y: + case AMI305_OFFSET_Y + 1: + case AMI305_OFFSET_Z: + case AMI305_OFFSET_Z + 1: + return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 || + ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; + case AMI306_CTRL4: + case AMI306_CTRL4 + 1: + return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306; + default: + return false; + } +} + +static bool ak8974_precious_reg(struct device *dev, unsigned int reg) +{ + return reg == AK8974_INT_CLEAR; +} + +static const struct regmap_config ak8974_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0xff, + .writeable_reg = ak8974_writeable_reg, + .precious_reg = ak8974_precious_reg, +}; + +static int ak8974_probe(struct i2c_client *i2c) +{ + struct iio_dev *indio_dev; + struct ak8974 *ak8974; + unsigned long irq_trig; + int irq = i2c->irq; + int ret; + + /* Register with IIO */ + indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974)); + if (indio_dev == NULL) + return -ENOMEM; + + ak8974 = iio_priv(indio_dev); + i2c_set_clientdata(i2c, indio_dev); + ak8974->i2c = i2c; + mutex_init(&ak8974->lock); + + ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation); + if (ret) + return ret; + + ak8974->regs[0].supply = ak8974_reg_avdd; + ak8974->regs[1].supply = ak8974_reg_dvdd; + + ret = devm_regulator_bulk_get(&i2c->dev, + ARRAY_SIZE(ak8974->regs), + ak8974->regs); + if (ret < 0) + return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n"); + + ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); + if (ret < 0) { + dev_err(&i2c->dev, "cannot enable regulators\n"); + return ret; + } + + /* Take runtime PM online */ + pm_runtime_get_noresume(&i2c->dev); + pm_runtime_set_active(&i2c->dev); + pm_runtime_enable(&i2c->dev); + + ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config); + if (IS_ERR(ak8974->map)) { + dev_err(&i2c->dev, "failed to allocate register map\n"); + pm_runtime_put_noidle(&i2c->dev); + pm_runtime_disable(&i2c->dev); + return PTR_ERR(ak8974->map); + } + + ret = ak8974_set_power(ak8974, AK8974_PWR_ON); + if (ret) { + dev_err(&i2c->dev, "could not power on\n"); + goto disable_pm; + } + + ret = ak8974_detect(ak8974); + if (ret) { + dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n"); + goto disable_pm; + } + + ret = ak8974_selftest(ak8974); + if (ret) + dev_err(&i2c->dev, "selftest failed (continuing anyway)\n"); + + ret = ak8974_reset(ak8974); + if (ret) { + dev_err(&i2c->dev, "AK8974 reset failed\n"); + goto disable_pm; + } + + switch (ak8974->variant) { + case AK8974_WHOAMI_VALUE_AMI306: + case AK8974_WHOAMI_VALUE_AMI305: + indio_dev->channels = ak8974_12_bits_channels; + indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); + break; + case AK8974_WHOAMI_VALUE_HSCDTD008A: + indio_dev->channels = ak8974_15_bits_channels; + indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels); + break; + default: + indio_dev->channels = ak8974_12_bits_channels; + indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels); + break; + } + indio_dev->info = &ak8974_info; + indio_dev->available_scan_masks = ak8974_scan_masks; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = ak8974->name; + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + ak8974_handle_trigger, + NULL); + if (ret) { + dev_err(&i2c->dev, "triggered buffer setup failed\n"); + goto disable_pm; + } + + /* If we have a valid DRDY IRQ, make use of it */ + if (irq > 0) { + irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq)); + if (irq_trig == IRQF_TRIGGER_RISING) { + dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n"); + } else if (irq_trig == IRQF_TRIGGER_FALLING) { + ak8974->drdy_active_low = true; + dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n"); + } else { + irq_trig = IRQF_TRIGGER_RISING; + } + irq_trig |= IRQF_ONESHOT; + irq_trig |= IRQF_SHARED; + + ret = devm_request_threaded_irq(&i2c->dev, + irq, + ak8974_drdy_irq, + ak8974_drdy_irq_thread, + irq_trig, + ak8974->name, + ak8974); + if (ret) { + dev_err(&i2c->dev, "unable to request DRDY IRQ " + "- proceeding without IRQ\n"); + goto no_irq; + } + ak8974->drdy_irq = true; + } + +no_irq: + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&i2c->dev, "device register failed\n"); + goto cleanup_buffer; + } + + pm_runtime_set_autosuspend_delay(&i2c->dev, + AK8974_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(&i2c->dev); + pm_runtime_put(&i2c->dev); + + return 0; + +cleanup_buffer: + iio_triggered_buffer_cleanup(indio_dev); +disable_pm: + pm_runtime_put_noidle(&i2c->dev); + pm_runtime_disable(&i2c->dev); + ak8974_set_power(ak8974, AK8974_PWR_OFF); + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); + + return ret; +} + +static void ak8974_remove(struct i2c_client *i2c) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(i2c); + struct ak8974 *ak8974 = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + pm_runtime_get_sync(&i2c->dev); + pm_runtime_put_noidle(&i2c->dev); + pm_runtime_disable(&i2c->dev); + ak8974_set_power(ak8974, AK8974_PWR_OFF); + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); +} + +static int ak8974_runtime_suspend(struct device *dev) +{ + struct ak8974 *ak8974 = + iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + + ak8974_set_power(ak8974, AK8974_PWR_OFF); + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); + + return 0; +} + +static int ak8974_runtime_resume(struct device *dev) +{ + struct ak8974 *ak8974 = + iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + int ret; + + ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs); + if (ret) + return ret; + msleep(AK8974_POWERON_DELAY); + ret = ak8974_set_power(ak8974, AK8974_PWR_ON); + if (ret) + goto out_regulator_disable; + + ret = ak8974_configure(ak8974); + if (ret) + goto out_disable_power; + + return 0; + +out_disable_power: + ak8974_set_power(ak8974, AK8974_PWR_OFF); +out_regulator_disable: + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); + + return ret; +} + +static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend, + ak8974_runtime_resume, NULL); + +static const struct i2c_device_id ak8974_id[] = { + {"ami305", 0 }, + {"ami306", 0 }, + {"ak8974", 0 }, + {"hscdtd008a", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, ak8974_id); + +static const struct of_device_id ak8974_of_match[] = { + { .compatible = "asahi-kasei,ak8974", }, + { .compatible = "alps,hscdtd008a", }, + {} +}; +MODULE_DEVICE_TABLE(of, ak8974_of_match); + +static struct i2c_driver ak8974_driver = { + .driver = { + .name = "ak8974", + .pm = pm_ptr(&ak8974_dev_pm_ops), + .of_match_table = ak8974_of_match, + }, + .probe = ak8974_probe, + .remove = ak8974_remove, + .id_table = ak8974_id, +}; +module_i2c_driver(ak8974_driver); + +MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver"); +MODULE_AUTHOR("Samu Onkalo"); +MODULE_AUTHOR("Linus Walleij"); +MODULE_LICENSE("GPL v2"); |