--- /dev/null
+// 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");
projects / linux.git / commitdiff