diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/iio/magnetometer/yamaha-yas530.c | 1049 |
1 files changed, 1049 insertions, 0 deletions
diff --git a/drivers/iio/magnetometer/yamaha-yas530.c b/drivers/iio/magnetometer/yamaha-yas530.c new file mode 100644 index 000000000000..d46f23d82b3d --- /dev/null +++ b/drivers/iio/magnetometer/yamaha-yas530.c @@ -0,0 +1,1049 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for the Yamaha YAS magnetic sensors, often used in Samsung + * mobile phones. While all are not yet handled because of lacking + * hardware, expand this driver to handle the different variants: + * + * YAS530 MS-3E (2011 Samsung Galaxy S Advance) + * YAS532 MS-3R (2011 Samsung Galaxy S4) + * YAS533 MS-3F (Vivo 1633, 1707, V3, Y21L) + * (YAS534 is a magnetic switch, not handled) + * YAS535 MS-6C + * YAS536 MS-3W + * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5, Xiaomi) + * YAS539 MS-3S (2018 Samsung Galaxy A7 SM-A750FN) + * + * Code functions found in the MPU3050 YAS530 and YAS532 drivers + * named "inv_compass" in the Tegra Android kernel tree. + * Copyright (C) 2012 InvenSense Corporation + * + * Author: Linus Walleij <linus.walleij@linaro.org> + */ +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/gpio/consumer.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/mutex.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/random.h> +#include <linux/unaligned/be_byteshift.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +/* This register map covers YAS530 and YAS532 but differs in YAS 537 and YAS539 */ +#define YAS5XX_DEVICE_ID 0x80 +#define YAS5XX_ACTUATE_INIT_COIL 0x81 +#define YAS5XX_MEASURE 0x82 +#define YAS5XX_CONFIG 0x83 +#define YAS5XX_MEASURE_INTERVAL 0x84 +#define YAS5XX_OFFSET_X 0x85 /* [-31 .. 31] */ +#define YAS5XX_OFFSET_Y1 0x86 /* [-31 .. 31] */ +#define YAS5XX_OFFSET_Y2 0x87 /* [-31 .. 31] */ +#define YAS5XX_TEST1 0x88 +#define YAS5XX_TEST2 0x89 +#define YAS5XX_CAL 0x90 +#define YAS5XX_MEASURE_DATA 0xB0 + +/* Bits in the YAS5xx config register */ +#define YAS5XX_CONFIG_INTON BIT(0) /* Interrupt on? */ +#define YAS5XX_CONFIG_INTHACT BIT(1) /* Interrupt active high? */ +#define YAS5XX_CONFIG_CCK_MASK GENMASK(4, 2) +#define YAS5XX_CONFIG_CCK_SHIFT 2 + +/* Bits in the measure command register */ +#define YAS5XX_MEASURE_START BIT(0) +#define YAS5XX_MEASURE_LDTC BIT(1) +#define YAS5XX_MEASURE_FORS BIT(2) +#define YAS5XX_MEASURE_DLYMES BIT(4) + +/* Bits in the measure data register */ +#define YAS5XX_MEASURE_DATA_BUSY BIT(7) + +#define YAS530_DEVICE_ID 0x01 /* YAS530 (MS-3E) */ +#define YAS530_VERSION_A 0 /* YAS530 (MS-3E A) */ +#define YAS530_VERSION_B 1 /* YAS530B (MS-3E B) */ +#define YAS530_VERSION_A_COEF 380 +#define YAS530_VERSION_B_COEF 550 +#define YAS530_DATA_BITS 12 +#define YAS530_DATA_CENTER BIT(YAS530_DATA_BITS - 1) +#define YAS530_DATA_OVERFLOW (BIT(YAS530_DATA_BITS) - 1) + +#define YAS532_DEVICE_ID 0x02 /* YAS532/YAS533 (MS-3R/F) */ +#define YAS532_VERSION_AB 0 /* YAS532/533 AB (MS-3R/F AB) */ +#define YAS532_VERSION_AC 1 /* YAS532/533 AC (MS-3R/F AC) */ +#define YAS532_VERSION_AB_COEF 1800 +#define YAS532_VERSION_AC_COEF_X 850 +#define YAS532_VERSION_AC_COEF_Y1 750 +#define YAS532_VERSION_AC_COEF_Y2 750 +#define YAS532_DATA_BITS 13 +#define YAS532_DATA_CENTER BIT(YAS532_DATA_BITS - 1) +#define YAS532_DATA_OVERFLOW (BIT(YAS532_DATA_BITS) - 1) +#define YAS532_20DEGREES 390 /* Looks like Kelvin */ + +/* These variant IDs are known from code dumps */ +#define YAS537_DEVICE_ID 0x07 /* YAS537 (MS-3T) */ +#define YAS539_DEVICE_ID 0x08 /* YAS539 (MS-3S) */ + +/* Turn off device regulators etc after 5 seconds of inactivity */ +#define YAS5XX_AUTOSUSPEND_DELAY_MS 5000 + +struct yas5xx_calibration { + /* Linearization calibration x, y1, y2 */ + s32 r[3]; + u32 f[3]; + /* Temperature compensation calibration */ + s32 Cx, Cy1, Cy2; + /* Misc calibration coefficients */ + s32 a2, a3, a4, a5, a6, a7, a8, a9, k; + /* clock divider */ + u8 dck; +}; + +/** + * struct yas5xx - state container for the YAS5xx driver + * @dev: parent device pointer + * @devid: device ID number + * @version: device version + * @name: device name + * @calibration: calibration settings from the OTP storage + * @hard_offsets: offsets for each axis measured with initcoil actuated + * @orientation: mounting matrix, flipped axis etc + * @map: regmap to access the YAX5xx registers over I2C + * @regs: the vdd and vddio power regulators + * @reset: optional GPIO line used for handling RESET + * @lock: locks the magnetometer for exclusive use during a measurement (which + * involves several register transactions so the regmap lock is not enough) + * so that measurements get serialized in a first-come-first serve manner + * @scan: naturally aligned measurements + */ +struct yas5xx { + struct device *dev; + unsigned int devid; + unsigned int version; + char name[16]; + struct yas5xx_calibration calibration; + u8 hard_offsets[3]; + struct iio_mount_matrix orientation; + struct regmap *map; + struct regulator_bulk_data regs[2]; + struct gpio_desc *reset; + struct mutex lock; + /* + * The scanout is 4 x 32 bits in CPU endianness. + * Ensure timestamp is naturally aligned + */ + struct { + s32 channels[4]; + s64 ts __aligned(8); + } scan; +}; + +/* On YAS530 the x, y1 and y2 values are 12 bits */ +static u16 yas530_extract_axis(u8 *data) +{ + u16 val; + + /* + * These are the bits used in a 16bit word: + * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * x x x x x x x x x x x x + */ + val = get_unaligned_be16(&data[0]); + val = FIELD_GET(GENMASK(14, 3), val); + return val; +} + +/* On YAS532 the x, y1 and y2 values are 13 bits */ +static u16 yas532_extract_axis(u8 *data) +{ + u16 val; + + /* + * These are the bits used in a 16bit word: + * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * x x x x x x x x x x x x x + */ + val = get_unaligned_be16(&data[0]); + val = FIELD_GET(GENMASK(14, 2), val); + return val; +} + +/** + * yas5xx_measure() - Make a measure from the hardware + * @yas5xx: The device state + * @t: the raw temperature measurement + * @x: the raw x axis measurement + * @y1: the y1 axis measurement + * @y2: the y2 axis measurement + * @return: 0 on success or error code + */ +static int yas5xx_measure(struct yas5xx *yas5xx, u16 *t, u16 *x, u16 *y1, u16 *y2) +{ + unsigned int busy; + u8 data[8]; + int ret; + u16 val; + + mutex_lock(&yas5xx->lock); + ret = regmap_write(yas5xx->map, YAS5XX_MEASURE, YAS5XX_MEASURE_START); + if (ret < 0) + goto out_unlock; + + /* + * Typical time to measure 1500 us, max 2000 us so wait min 500 us + * and at most 20000 us (one magnitude more than the datsheet max) + * before timeout. + */ + ret = regmap_read_poll_timeout(yas5xx->map, YAS5XX_MEASURE_DATA, busy, + !(busy & YAS5XX_MEASURE_DATA_BUSY), + 500, 20000); + if (ret) { + dev_err(yas5xx->dev, "timeout waiting for measurement\n"); + goto out_unlock; + } + + ret = regmap_bulk_read(yas5xx->map, YAS5XX_MEASURE_DATA, + data, sizeof(data)); + if (ret) + goto out_unlock; + + mutex_unlock(&yas5xx->lock); + + switch (yas5xx->devid) { + case YAS530_DEVICE_ID: + /* + * The t value is 9 bits in big endian format + * These are the bits used in a 16bit word: + * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * x x x x x x x x x + */ + val = get_unaligned_be16(&data[0]); + val = FIELD_GET(GENMASK(14, 6), val); + *t = val; + *x = yas530_extract_axis(&data[2]); + *y1 = yas530_extract_axis(&data[4]); + *y2 = yas530_extract_axis(&data[6]); + break; + case YAS532_DEVICE_ID: + /* + * The t value is 10 bits in big endian format + * These are the bits used in a 16bit word: + * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + * x x x x x x x x x x + */ + val = get_unaligned_be16(&data[0]); + val = FIELD_GET(GENMASK(14, 5), val); + *t = val; + *x = yas532_extract_axis(&data[2]); + *y1 = yas532_extract_axis(&data[4]); + *y2 = yas532_extract_axis(&data[6]); + break; + default: + dev_err(yas5xx->dev, "unknown data format\n"); + ret = -EINVAL; + break; + } + + return ret; + +out_unlock: + mutex_unlock(&yas5xx->lock); + return ret; +} + +static s32 yas5xx_linearize(struct yas5xx *yas5xx, u16 val, int axis) +{ + struct yas5xx_calibration *c = &yas5xx->calibration; + static const s32 yas532ac_coef[] = { + YAS532_VERSION_AC_COEF_X, + YAS532_VERSION_AC_COEF_Y1, + YAS532_VERSION_AC_COEF_Y2, + }; + s32 coef; + + /* Select coefficients */ + switch (yas5xx->devid) { + case YAS530_DEVICE_ID: + if (yas5xx->version == YAS530_VERSION_A) + coef = YAS530_VERSION_A_COEF; + else + coef = YAS530_VERSION_B_COEF; + break; + case YAS532_DEVICE_ID: + if (yas5xx->version == YAS532_VERSION_AB) + coef = YAS532_VERSION_AB_COEF; + else + /* Elaborate coefficients */ + coef = yas532ac_coef[axis]; + break; + default: + dev_err(yas5xx->dev, "unknown device type\n"); + return val; + } + /* + * Linearization formula: + * + * x' = x - (3721 + 50 * f) + (xoffset - r) * c + * + * Where f and r are calibration values, c is a per-device + * and sometimes per-axis coefficient. + */ + return val - (3721 + 50 * c->f[axis]) + + (yas5xx->hard_offsets[axis] - c->r[axis]) * coef; +} + +/** + * yas5xx_get_measure() - Measure a sample of all axis and process + * @yas5xx: The device state + * @to: Temperature out + * @xo: X axis out + * @yo: Y axis out + * @zo: Z axis out + * @return: 0 on success or error code + * + * Returned values are in nanotesla according to some code. + */ +static int yas5xx_get_measure(struct yas5xx *yas5xx, s32 *to, s32 *xo, s32 *yo, s32 *zo) +{ + struct yas5xx_calibration *c = &yas5xx->calibration; + u16 t, x, y1, y2; + /* These are "signed x, signed y1 etc */ + s32 sx, sy1, sy2, sy, sz; + int ret; + + /* We first get raw data that needs to be translated to [x,y,z] */ + ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2); + if (ret) + return ret; + + /* Do some linearization if available */ + sx = yas5xx_linearize(yas5xx, x, 0); + sy1 = yas5xx_linearize(yas5xx, y1, 1); + sy2 = yas5xx_linearize(yas5xx, y2, 2); + + /* + * Temperature compensation for x, y1, y2 respectively: + * + * Cx * t + * x' = x - ------ + * 100 + */ + sx = sx - (c->Cx * t) / 100; + sy1 = sy1 - (c->Cy1 * t) / 100; + sy2 = sy2 - (c->Cy2 * t) / 100; + + /* + * Break y1 and y2 into y and z, y1 and y2 are apparently encoding + * y and z. + */ + sy = sy1 - sy2; + sz = -sy1 - sy2; + + /* + * FIXME: convert to Celsius? Just guessing this is given + * as 1/10:s of degrees so multiply by 100 to get millicentigrades. + */ + *to = t * 100; + /* + * Calibrate [x,y,z] with some formulas like this: + * + * 100 * x + a_2 * y + a_3 * z + * x' = k * --------------------------- + * 10 + * + * a_4 * x + a_5 * y + a_6 * z + * y' = k * --------------------------- + * 10 + * + * a_7 * x + a_8 * y + a_9 * z + * z' = k * --------------------------- + * 10 + */ + *xo = c->k * ((100 * sx + c->a2 * sy + c->a3 * sz) / 10); + *yo = c->k * ((c->a4 * sx + c->a5 * sy + c->a6 * sz) / 10); + *zo = c->k * ((c->a7 * sx + c->a8 * sy + c->a9 * sz) / 10); + + return 0; +} + +static int yas5xx_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, + long mask) +{ + struct yas5xx *yas5xx = iio_priv(indio_dev); + s32 t, x, y, z; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + pm_runtime_get_sync(yas5xx->dev); + ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z); + pm_runtime_mark_last_busy(yas5xx->dev); + pm_runtime_put_autosuspend(yas5xx->dev); + if (ret) + return ret; + switch (chan->address) { + case 0: + *val = t; + break; + case 1: + *val = x; + break; + case 2: + *val = y; + break; + case 3: + *val = z; + break; + default: + dev_err(yas5xx->dev, "unknown channel\n"); + return -EINVAL; + } + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + if (chan->address == 0) { + /* Temperature is unscaled */ + *val = 1; + return IIO_VAL_INT; + } + /* + * The axis values are in nanotesla according to the vendor + * drivers, but is clearly in microtesla according to + * experiments. Since 1 uT = 0.01 Gauss, we need to divide + * by 100000000 (10^8) to get to Gauss from the raw value. + */ + *val = 1; + *val2 = 100000000; + return IIO_VAL_FRACTIONAL; + default: + /* Unknown request */ + return -EINVAL; + } +} + +static void yas5xx_fill_buffer(struct iio_dev *indio_dev) +{ + struct yas5xx *yas5xx = iio_priv(indio_dev); + s32 t, x, y, z; + int ret; + + pm_runtime_get_sync(yas5xx->dev); + ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z); + pm_runtime_mark_last_busy(yas5xx->dev); + pm_runtime_put_autosuspend(yas5xx->dev); + if (ret) { + dev_err(yas5xx->dev, "error refilling buffer\n"); + return; + } + yas5xx->scan.channels[0] = t; + yas5xx->scan.channels[1] = x; + yas5xx->scan.channels[2] = y; + yas5xx->scan.channels[3] = z; + iio_push_to_buffers_with_timestamp(indio_dev, &yas5xx->scan, + iio_get_time_ns(indio_dev)); +} + +static irqreturn_t yas5xx_handle_trigger(int irq, void *p) +{ + const struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + + yas5xx_fill_buffer(indio_dev); + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + + +static const struct iio_mount_matrix * +yas5xx_get_mount_matrix(const struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct yas5xx *yas5xx = iio_priv(indio_dev); + + return &yas5xx->orientation; +} + +static const struct iio_chan_spec_ext_info yas5xx_ext_info[] = { + IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, yas5xx_get_mount_matrix), + { } +}; + +#define YAS5XX_AXIS_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), \ + .ext_info = yas5xx_ext_info, \ + .address = index, \ + .scan_index = index, \ + .scan_type = { \ + .sign = 's', \ + .realbits = 32, \ + .storagebits = 32, \ + .endianness = IIO_CPU, \ + }, \ + } + +static const struct iio_chan_spec yas5xx_channels[] = { + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + .address = 0, + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + YAS5XX_AXIS_CHANNEL(X, 1), + YAS5XX_AXIS_CHANNEL(Y, 2), + YAS5XX_AXIS_CHANNEL(Z, 3), + IIO_CHAN_SOFT_TIMESTAMP(4), +}; + +static const unsigned long yas5xx_scan_masks[] = { GENMASK(3, 0), 0 }; + +static const struct iio_info yas5xx_info = { + .read_raw = &yas5xx_read_raw, +}; + +static bool yas5xx_volatile_reg(struct device *dev, unsigned int reg) +{ + return reg == YAS5XX_ACTUATE_INIT_COIL || + reg == YAS5XX_MEASURE || + (reg >= YAS5XX_MEASURE_DATA && reg <= YAS5XX_MEASURE_DATA + 8); +} + +/* TODO: enable regmap cache, using mark dirty and sync at runtime resume */ +static const struct regmap_config yas5xx_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0xff, + .volatile_reg = yas5xx_volatile_reg, +}; + +/** + * yas53x_extract_calibration() - extracts the a2-a9 and k calibration + * @data: the bitfield to use + * @c: the calibration to populate + */ +static void yas53x_extract_calibration(u8 *data, struct yas5xx_calibration *c) +{ + u64 val = get_unaligned_be64(data); + + /* + * Bitfield layout for the axis calibration data, for factor + * a2 = 2 etc, k = k, c = clock divider + * + * n 7 6 5 4 3 2 1 0 + * 0 [ 2 2 2 2 2 2 3 3 ] bits 63 .. 56 + * 1 [ 3 3 4 4 4 4 4 4 ] bits 55 .. 48 + * 2 [ 5 5 5 5 5 5 6 6 ] bits 47 .. 40 + * 3 [ 6 6 6 6 7 7 7 7 ] bits 39 .. 32 + * 4 [ 7 7 7 8 8 8 8 8 ] bits 31 .. 24 + * 5 [ 8 9 9 9 9 9 9 9 ] bits 23 .. 16 + * 6 [ 9 k k k k k c c ] bits 15 .. 8 + * 7 [ c x x x x x x x ] bits 7 .. 0 + */ + c->a2 = FIELD_GET(GENMASK_ULL(63, 58), val) - 32; + c->a3 = FIELD_GET(GENMASK_ULL(57, 54), val) - 8; + c->a4 = FIELD_GET(GENMASK_ULL(53, 48), val) - 32; + c->a5 = FIELD_GET(GENMASK_ULL(47, 42), val) + 38; + c->a6 = FIELD_GET(GENMASK_ULL(41, 36), val) - 32; + c->a7 = FIELD_GET(GENMASK_ULL(35, 29), val) - 64; + c->a8 = FIELD_GET(GENMASK_ULL(28, 23), val) - 32; + c->a9 = FIELD_GET(GENMASK_ULL(22, 15), val); + c->k = FIELD_GET(GENMASK_ULL(14, 10), val) + 10; + c->dck = FIELD_GET(GENMASK_ULL(9, 7), val); +} + +static int yas530_get_calibration_data(struct yas5xx *yas5xx) +{ + struct yas5xx_calibration *c = &yas5xx->calibration; + u8 data[16]; + u32 val; + int ret; + + /* Dummy read, first read is ALWAYS wrong */ + ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); + if (ret) + return ret; + + /* Actual calibration readout */ + ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); + if (ret) + return ret; + dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data); + + add_device_randomness(data, sizeof(data)); + yas5xx->version = data[15] & GENMASK(1, 0); + + /* Extract the calibration from the bitfield */ + c->Cx = data[0] * 6 - 768; + c->Cy1 = data[1] * 6 - 768; + c->Cy2 = data[2] * 6 - 768; + yas53x_extract_calibration(&data[3], c); + + /* + * Extract linearization: + * Linearization layout in the 32 bits at byte 11: + * The r factors are 6 bit values where bit 5 is the sign + * + * n 7 6 5 4 3 2 1 0 + * 0 [ xx xx xx r0 r0 r0 r0 r0 ] bits 31 .. 24 + * 1 [ r0 f0 f0 r1 r1 r1 r1 r1 ] bits 23 .. 16 + * 2 [ r1 f1 f1 r2 r2 r2 r2 r2 ] bits 15 .. 8 + * 3 [ r2 f2 f2 xx xx xx xx xx ] bits 7 .. 0 + */ + val = get_unaligned_be32(&data[11]); + c->f[0] = FIELD_GET(GENMASK(22, 21), val); + c->f[1] = FIELD_GET(GENMASK(14, 13), val); + c->f[2] = FIELD_GET(GENMASK(6, 5), val); + c->r[0] = sign_extend32(FIELD_GET(GENMASK(28, 23), val), 5); + c->r[1] = sign_extend32(FIELD_GET(GENMASK(20, 15), val), 5); + c->r[2] = sign_extend32(FIELD_GET(GENMASK(12, 7), val), 5); + return 0; +} + +static int yas532_get_calibration_data(struct yas5xx *yas5xx) +{ + struct yas5xx_calibration *c = &yas5xx->calibration; + u8 data[14]; + u32 val; + int ret; + + /* Dummy read, first read is ALWAYS wrong */ + ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); + if (ret) + return ret; + /* Actual calibration readout */ + ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data)); + if (ret) + return ret; + dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data); + + /* Sanity check, is this all zeroes? */ + if (memchr_inv(data, 0x00, 13)) { + if (!(data[13] & BIT(7))) + dev_warn(yas5xx->dev, "calibration is blank!\n"); + } + + add_device_randomness(data, sizeof(data)); + /* Only one bit of version info reserved here as far as we know */ + yas5xx->version = data[13] & BIT(0); + + /* Extract calibration from the bitfield */ + c->Cx = data[0] * 10 - 1280; + c->Cy1 = data[1] * 10 - 1280; + c->Cy2 = data[2] * 10 - 1280; + yas53x_extract_calibration(&data[3], c); + /* + * Extract linearization: + * Linearization layout in the 32 bits at byte 10: + * The r factors are 6 bit values where bit 5 is the sign + * + * n 7 6 5 4 3 2 1 0 + * 0 [ xx r0 r0 r0 r0 r0 r0 f0 ] bits 31 .. 24 + * 1 [ f0 r1 r1 r1 r1 r1 r1 f1 ] bits 23 .. 16 + * 2 [ f1 r2 r2 r2 r2 r2 r2 f2 ] bits 15 .. 8 + * 3 [ f2 xx xx xx xx xx xx xx ] bits 7 .. 0 + */ + val = get_unaligned_be32(&data[10]); + c->f[0] = FIELD_GET(GENMASK(24, 23), val); + c->f[1] = FIELD_GET(GENMASK(16, 15), val); + c->f[2] = FIELD_GET(GENMASK(8, 7), val); + c->r[0] = sign_extend32(FIELD_GET(GENMASK(30, 25), val), 5); + c->r[1] = sign_extend32(FIELD_GET(GENMASK(22, 17), val), 5); + c->r[2] = sign_extend32(FIELD_GET(GENMASK(14, 7), val), 5); + + return 0; +} + +static void yas5xx_dump_calibration(struct yas5xx *yas5xx) +{ + struct yas5xx_calibration *c = &yas5xx->calibration; + + dev_dbg(yas5xx->dev, "f[] = [%d, %d, %d]\n", + c->f[0], c->f[1], c->f[2]); + dev_dbg(yas5xx->dev, "r[] = [%d, %d, %d]\n", + c->r[0], c->r[1], c->r[2]); + dev_dbg(yas5xx->dev, "Cx = %d\n", c->Cx); + dev_dbg(yas5xx->dev, "Cy1 = %d\n", c->Cy1); + dev_dbg(yas5xx->dev, "Cy2 = %d\n", c->Cy2); + dev_dbg(yas5xx->dev, "a2 = %d\n", c->a2); + dev_dbg(yas5xx->dev, "a3 = %d\n", c->a3); + dev_dbg(yas5xx->dev, "a4 = %d\n", c->a4); + dev_dbg(yas5xx->dev, "a5 = %d\n", c->a5); + dev_dbg(yas5xx->dev, "a6 = %d\n", c->a6); + dev_dbg(yas5xx->dev, "a7 = %d\n", c->a7); + dev_dbg(yas5xx->dev, "a8 = %d\n", c->a8); + dev_dbg(yas5xx->dev, "a9 = %d\n", c->a9); + dev_dbg(yas5xx->dev, "k = %d\n", c->k); + dev_dbg(yas5xx->dev, "dck = %d\n", c->dck); +} + +static int yas5xx_set_offsets(struct yas5xx *yas5xx, s8 ox, s8 oy1, s8 oy2) +{ + int ret; + + ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_X, ox); + if (ret) + return ret; + ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_Y1, oy1); + if (ret) + return ret; + return regmap_write(yas5xx->map, YAS5XX_OFFSET_Y2, oy2); +} + +static s8 yas5xx_adjust_offset(s8 old, int bit, u16 center, u16 measure) +{ + if (measure > center) + return old + BIT(bit); + if (measure < center) + return old - BIT(bit); + return old; +} + +static int yas5xx_meaure_offsets(struct yas5xx *yas5xx) +{ + int ret; + u16 center; + u16 t, x, y1, y2; + s8 ox, oy1, oy2; + int i; + + /* Actuate the init coil and measure offsets */ + ret = regmap_write(yas5xx->map, YAS5XX_ACTUATE_INIT_COIL, 0); + if (ret) + return ret; + + /* When the initcoil is active this should be around the center */ + switch (yas5xx->devid) { + case YAS530_DEVICE_ID: + center = YAS530_DATA_CENTER; + break; + case YAS532_DEVICE_ID: + center = YAS532_DATA_CENTER; + break; + default: + dev_err(yas5xx->dev, "unknown device type\n"); + return -EINVAL; + } + + /* + * We set offsets in the interval +-31 by iterating + * +-16, +-8, +-4, +-2, +-1 adjusting the offsets each + * time, then writing the final offsets into the + * registers. + * + * NOTE: these offsets are NOT in the same unit or magnitude + * as the values for [x, y1, y2]. The value is +/-31 + * but the effect on the raw values is much larger. + * The effect of the offset is to bring the measure + * rougly to the center. + */ + ox = 0; + oy1 = 0; + oy2 = 0; + + for (i = 4; i >= 0; i--) { + ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2); + if (ret) + return ret; + + ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2); + if (ret) + return ret; + dev_dbg(yas5xx->dev, "measurement %d: x=%d, y1=%d, y2=%d\n", + 5-i, x, y1, y2); + + ox = yas5xx_adjust_offset(ox, i, center, x); + oy1 = yas5xx_adjust_offset(oy1, i, center, y1); + oy2 = yas5xx_adjust_offset(oy2, i, center, y2); + } + + /* Needed for calibration algorithm */ + yas5xx->hard_offsets[0] = ox; + yas5xx->hard_offsets[1] = oy1; + yas5xx->hard_offsets[2] = oy2; + ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2); + if (ret) + return ret; + + dev_info(yas5xx->dev, "discovered hard offsets: x=%d, y1=%d, y2=%d\n", + ox, oy1, oy2); + return 0; +} + +static int yas5xx_power_on(struct yas5xx *yas5xx) +{ + unsigned int val; + int ret; + + /* Zero the test registers */ + ret = regmap_write(yas5xx->map, YAS5XX_TEST1, 0); + if (ret) + return ret; + ret = regmap_write(yas5xx->map, YAS5XX_TEST2, 0); + if (ret) + return ret; + + /* Set up for no interrupts, calibrated clock divider */ + val = FIELD_PREP(YAS5XX_CONFIG_CCK_MASK, yas5xx->calibration.dck); + ret = regmap_write(yas5xx->map, YAS5XX_CONFIG, val); + if (ret) + return ret; + + /* Measure interval 0 (back-to-back?) */ + return regmap_write(yas5xx->map, YAS5XX_MEASURE_INTERVAL, 0); +} + +static int yas5xx_probe(struct i2c_client *i2c, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct device *dev = &i2c->dev; + struct yas5xx *yas5xx; + int ret; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*yas5xx)); + if (!indio_dev) + return -ENOMEM; + + yas5xx = iio_priv(indio_dev); + i2c_set_clientdata(i2c, indio_dev); + yas5xx->dev = dev; + mutex_init(&yas5xx->lock); + + ret = iio_read_mount_matrix(dev, "mount-matrix", &yas5xx->orientation); + if (ret) + return ret; + + yas5xx->regs[0].supply = "vdd"; + yas5xx->regs[1].supply = "iovdd"; + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(yas5xx->regs), + yas5xx->regs); + if (ret) + return dev_err_probe(dev, ret, "cannot get regulators\n"); + + ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + if (ret) { + dev_err(dev, "cannot enable regulators\n"); + return ret; + } + + /* See comment in runtime resume callback */ + usleep_range(31000, 40000); + + /* This will take the device out of reset if need be */ + yas5xx->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(yas5xx->reset)) { + ret = dev_err_probe(dev, PTR_ERR(yas5xx->reset), + "failed to get reset line\n"); + goto reg_off; + } + + yas5xx->map = devm_regmap_init_i2c(i2c, &yas5xx_regmap_config); + if (IS_ERR(yas5xx->map)) { + dev_err(dev, "failed to allocate register map\n"); + ret = PTR_ERR(yas5xx->map); + goto assert_reset; + } + + ret = regmap_read(yas5xx->map, YAS5XX_DEVICE_ID, &yas5xx->devid); + if (ret) + goto assert_reset; + + switch (yas5xx->devid) { + case YAS530_DEVICE_ID: + ret = yas530_get_calibration_data(yas5xx); + if (ret) + goto assert_reset; + dev_info(dev, "detected YAS530 MS-3E %s", + yas5xx->version ? "B" : "A"); + strncpy(yas5xx->name, "yas530", sizeof(yas5xx->name)); + break; + case YAS532_DEVICE_ID: + ret = yas532_get_calibration_data(yas5xx); + if (ret) + goto assert_reset; + dev_info(dev, "detected YAS532/YAS533 MS-3R/F %s", + yas5xx->version ? "AC" : "AB"); + strncpy(yas5xx->name, "yas532", sizeof(yas5xx->name)); + break; + default: + dev_err(dev, "unhandled device ID %02x\n", yas5xx->devid); + goto assert_reset; + } + + yas5xx_dump_calibration(yas5xx); + ret = yas5xx_power_on(yas5xx); + if (ret) + goto assert_reset; + ret = yas5xx_meaure_offsets(yas5xx); + if (ret) + goto assert_reset; + + indio_dev->info = &yas5xx_info; + indio_dev->available_scan_masks = yas5xx_scan_masks; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = yas5xx->name; + indio_dev->channels = yas5xx_channels; + indio_dev->num_channels = ARRAY_SIZE(yas5xx_channels); + + ret = iio_triggered_buffer_setup(indio_dev, NULL, + yas5xx_handle_trigger, + NULL); + if (ret) { + dev_err(dev, "triggered buffer setup failed\n"); + goto assert_reset; + } + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(dev, "device register failed\n"); + goto cleanup_buffer; + } + + /* Take runtime PM online */ + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + pm_runtime_set_autosuspend_delay(dev, YAS5XX_AUTOSUSPEND_DELAY_MS); + pm_runtime_use_autosuspend(dev); + pm_runtime_put(dev); + + return 0; + +cleanup_buffer: + iio_triggered_buffer_cleanup(indio_dev); +assert_reset: + gpiod_set_value_cansleep(yas5xx->reset, 1); +reg_off: + regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + + return ret; +} + +static int yas5xx_remove(struct i2c_client *i2c) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(i2c); + struct yas5xx *yas5xx = iio_priv(indio_dev); + struct device *dev = &i2c->dev; + + iio_device_unregister(indio_dev); + iio_triggered_buffer_cleanup(indio_dev); + /* + * Now we can't get any more reads from the device, which would + * also call pm_runtime* functions and race with our disable + * code. Disable PM runtime in orderly fashion and power down. + */ + pm_runtime_get_sync(dev); + pm_runtime_put_noidle(dev); + pm_runtime_disable(dev); + gpiod_set_value_cansleep(yas5xx->reset, 1); + regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + + return 0; +} + +static int __maybe_unused yas5xx_runtime_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct yas5xx *yas5xx = iio_priv(indio_dev); + + gpiod_set_value_cansleep(yas5xx->reset, 1); + regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + + return 0; +} + +static int __maybe_unused yas5xx_runtime_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct yas5xx *yas5xx = iio_priv(indio_dev); + int ret; + + ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + if (ret) { + dev_err(dev, "cannot enable regulators\n"); + return ret; + } + + /* + * The YAS530 datasheet says TVSKW is up to 30 ms, after that 1 ms + * for all voltages to settle. The YAS532 is 10ms then 4ms for the + * I2C to come online. Let's keep it safe and put this at 31ms. + */ + usleep_range(31000, 40000); + gpiod_set_value_cansleep(yas5xx->reset, 0); + + ret = yas5xx_power_on(yas5xx); + if (ret) { + dev_err(dev, "cannot power on\n"); + goto out_reset; + } + + return 0; + +out_reset: + gpiod_set_value_cansleep(yas5xx->reset, 1); + regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs); + + return ret; +} + +static const struct dev_pm_ops yas5xx_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) + SET_RUNTIME_PM_OPS(yas5xx_runtime_suspend, + yas5xx_runtime_resume, NULL) +}; + +static const struct i2c_device_id yas5xx_id[] = { + {"yas530", }, + {"yas532", }, + {"yas533", }, + {} +}; +MODULE_DEVICE_TABLE(i2c, yas5xx_id); + +static const struct of_device_id yas5xx_of_match[] = { + { .compatible = "yamaha,yas530", }, + { .compatible = "yamaha,yas532", }, + { .compatible = "yamaha,yas533", }, + {} +}; +MODULE_DEVICE_TABLE(of, yas5xx_of_match); + +static struct i2c_driver yas5xx_driver = { + .driver = { + .name = "yas5xx", + .of_match_table = yas5xx_of_match, + .pm = &yas5xx_dev_pm_ops, + }, + .probe = yas5xx_probe, + .remove = yas5xx_remove, + .id_table = yas5xx_id, +}; +module_i2c_driver(yas5xx_driver); + +MODULE_DESCRIPTION("Yamaha YAS53x 3-axis magnetometer driver"); +MODULE_AUTHOR("Linus Walleij"); +MODULE_LICENSE("GPL v2"); |