| // 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/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 |
| */ |
| 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"; |
| /* fall-through */ |
| 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, |
| const struct i2c_device_id *id) |
| { |
| 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, "mount-matrix", |
| &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) { |
| if (ret != -EPROBE_DEFER) |
| dev_err(&i2c->dev, "cannot get regulators: %d\n", ret); |
| else |
| dev_dbg(&i2c->dev, |
| "regulators unavailable, deferring probe\n"); |
| |
| return ret; |
| } |
| |
| 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; |
| } |
| |
| indio_dev->dev.parent = &i2c->dev; |
| 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 int 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); |
| |
| return 0; |
| } |
| |
| static int __maybe_unused 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 __maybe_unused 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 const struct dev_pm_ops ak8974_dev_pm_ops = { |
| SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, |
| pm_runtime_force_resume) |
| SET_RUNTIME_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 = &ak8974_dev_pm_ops, |
| .of_match_table = of_match_ptr(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"); |