]> git.baikalelectronics.ru Git - kernel.git/commitdiff
iio: Add SEMTECH SX9310/9311 sensor driver
authorDaniel Campello <campello@chromium.org>
Tue, 10 Mar 2020 20:06:59 +0000 (14:06 -0600)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Sat, 21 Mar 2020 10:28:20 +0000 (10:28 +0000)
Add SEMTECH SX9310/9311 driver.

The device has the following entry points:

Usual frequency:
- sampling_frequency
- sampling_frequency_available

Instant reading of current values for different sensors:
- in_proximity0_raw
- in_proximity1_raw
- in_proximity2_raw
- in_proximity3_comb_raw
and associated events in events/

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enrico Granata <egranata@chromium.org>
Signed-off-by: Daniel Campello <campello@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Documentation/ABI/testing/sysfs-bus-iio-sx9310 [new file with mode: 0644]
drivers/iio/proximity/Kconfig
drivers/iio/proximity/Makefile
drivers/iio/proximity/sx9310.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-sx9310 b/Documentation/ABI/testing/sysfs-bus-iio-sx9310
new file mode 100644 (file)
index 0000000..3ac7759
--- /dev/null
@@ -0,0 +1,10 @@
+What:          /sys/bus/iio/devices/iio:deviceX/in_proximity3_comb_raw
+Date:          February 2019
+KernelVersion: 5.6
+Contact:       Daniel Campello <campello@chromium.org>
+Description:
+               Proximity measurement indicating that some object is
+               near the combined sensor. The combined sensor presents
+               proximity measurements constructed by hardware by
+               combining measurements taken from a given set of
+               physical sensors.
index 37606d400805a9bdf79bd647716caa07b356925e..d57e8cc17e42d661a8440129268d9af21be6cece 100644 (file)
@@ -101,6 +101,19 @@ config SRF04
          To compile this driver as a module, choose M here: the
          module will be called srf04.
 
+config SX9310
+       tristate "SX9310/SX9311 Semtech proximity sensor"
+       select IIO_BUFFER
+       select IIO_TRIGGERED_BUFFER
+       select REGMAP_I2C
+       depends on I2C
+       help
+         Say Y here to build a driver for Semtech's SX9310/SX9311 capacitive
+         proximity/button sensor.
+
+         To compile this driver as a module, choose M here: the
+         module will be called sx9310.
+
 config SX9500
        tristate "SX9500 Semtech proximity sensor"
        select IIO_BUFFER
index c591b019304e7f585cdf803f6b7987663db0ec8d..25e5a04da101c5f7135eb9ba5446464e475cd8bc 100644 (file)
@@ -12,6 +12,7 @@ obj-$(CONFIG_PING)            += ping.o
 obj-$(CONFIG_RFD77402)         += rfd77402.o
 obj-$(CONFIG_SRF04)            += srf04.o
 obj-$(CONFIG_SRF08)            += srf08.o
+obj-$(CONFIG_SX9310)           += sx9310.o
 obj-$(CONFIG_SX9500)           += sx9500.o
 obj-$(CONFIG_VL53L0X_I2C)      += vl53l0x-i2c.o
 
diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
new file mode 100644 (file)
index 0000000..d161f30
--- /dev/null
@@ -0,0 +1,1069 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018 Google LLC.
+ *
+ * Driver for Semtech's SX9310/SX9311 capacitive proximity/button solution.
+ * Based on SX9500 driver and Semtech driver using the input framework
+ * <https://my.syncplicity.com/share/teouwsim8niiaud/
+ *          linux-driver-SX9310_NoSmartHSensing>.
+ * Reworked April 2019 by Evan Green <evgreen@chromium.org>
+ * and January 2020 by Daniel Campello <campello@chromium.org>
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+/* Register definitions. */
+#define SX9310_REG_IRQ_SRC                             0x00
+#define SX9310_REG_STAT0                               0x01
+#define SX9310_REG_STAT1                               0x02
+#define SX9310_REG_IRQ_MSK                             0x03
+#define   SX9310_CONVDONE_IRQ                          BIT(3)
+#define   SX9310_FAR_IRQ                               BIT(5)
+#define   SX9310_CLOSE_IRQ                             BIT(6)
+#define   SX9310_EVENT_IRQ                             (SX9310_FAR_IRQ | \
+                                                        SX9310_CLOSE_IRQ)
+#define SX9310_REG_IRQ_FUNC                            0x04
+
+#define SX9310_REG_PROX_CTRL0                          0x10
+#define   SX9310_REG_PROX_CTRL0_PROXSTAT2              0x10
+#define   SX9310_REG_PROX_CTRL0_EN_MASK                        0x0F
+#define SX9310_REG_PROX_CTRL1                          0x11
+#define SX9310_REG_PROX_CTRL2                          0x12
+#define   SX9310_REG_PROX_CTRL2_COMBMODE_ALL           0x80
+#define   SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC       0x04
+#define SX9310_REG_PROX_CTRL3                          0x13
+#define   SX9310_REG_PROX_CTRL3_GAIN0_X8               0x0c
+#define   SX9310_REG_PROX_CTRL3_GAIN12_X4              0x02
+#define SX9310_REG_PROX_CTRL4                          0x14
+#define   SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST      0x07
+#define SX9310_REG_PROX_CTRL5                          0x15
+#define   SX9310_REG_PROX_CTRL5_RANGE_SMALL            0xc0
+#define   SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1                0x04
+#define   SX9310_REG_PROX_CTRL5_RAWFILT_1P25           0x02
+#define SX9310_REG_PROX_CTRL6                          0x16
+#define   SX9310_REG_PROX_CTRL6_COMP_COMMON            0x20
+#define SX9310_REG_PROX_CTRL7                          0x17
+#define   SX9310_REG_PROX_CTRL7_AVGNEGFILT_2           0x08
+#define   SX9310_REG_PROX_CTRL7_AVGPOSFILT_512         0x05
+#define SX9310_REG_PROX_CTRL8                          0x18
+#define SX9310_REG_PROX_CTRL9                          0x19
+#define   SX9310_REG_PROX_CTRL8_9_PTHRESH12_28         0x40
+#define   SX9310_REG_PROX_CTRL8_9_PTHRESH_96           0x88
+#define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900       0x03
+#define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500      0x05
+#define SX9310_REG_PROX_CTRL10                         0x1a
+#define   SX9310_REG_PROX_CTRL10_HYST_6PCT             0x10
+#define   SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_8      0x12
+#define   SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_8                0x03
+#define SX9310_REG_PROX_CTRL11                         0x1b
+#define SX9310_REG_PROX_CTRL12                         0x1c
+#define SX9310_REG_PROX_CTRL13                         0x1d
+#define SX9310_REG_PROX_CTRL14                         0x1e
+#define SX9310_REG_PROX_CTRL15                         0x1f
+#define SX9310_REG_PROX_CTRL16                         0x20
+#define SX9310_REG_PROX_CTRL17                         0x21
+#define SX9310_REG_PROX_CTRL18                         0x22
+#define SX9310_REG_PROX_CTRL19                         0x23
+#define SX9310_REG_SAR_CTRL0                           0x2a
+#define   SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES                0x40
+#define   SX9310_REG_SAR_CTRL0_SARHYST_8               0x10
+#define SX9310_REG_SAR_CTRL1                           0x2b
+/* Each increment of the slope register is 0.0078125. */
+#define   SX9310_REG_SAR_CTRL1_SLOPE(_hnslope)         (_hnslope / 78125)
+#define SX9310_REG_SAR_CTRL2                           0x2c
+#define   SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT       0x3c
+
+#define SX9310_REG_SENSOR_SEL                          0x30
+
+#define SX9310_REG_USE_MSB                             0x31
+#define SX9310_REG_USE_LSB                             0x32
+
+#define SX9310_REG_AVG_MSB                             0x33
+#define SX9310_REG_AVG_LSB                             0x34
+
+#define SX9310_REG_DIFF_MSB                            0x35
+#define SX9310_REG_DIFF_LSB                            0x36
+
+#define SX9310_REG_OFFSET_MSB                          0x37
+#define SX9310_REG_OFFSET_LSB                          0x38
+
+#define SX9310_REG_SAR_MSB                             0x39
+#define SX9310_REG_SAR_LSB                             0x3a
+
+#define SX9310_REG_I2CADDR                             0x40
+#define SX9310_REG_PAUSE                               0x41
+#define SX9310_REG_WHOAMI                              0x42
+#define   SX9310_WHOAMI_VALUE                          0x01
+#define   SX9311_WHOAMI_VALUE                          0x02
+
+#define SX9310_REG_RESET                               0x7f
+#define   SX9310_SOFT_RESET                            0xde
+
+#define SX9310_SCAN_PERIOD_MASK                                GENMASK(7, 4)
+#define SX9310_SCAN_PERIOD_SHIFT                       4
+
+#define SX9310_COMPSTAT_MASK                           GENMASK(3, 0)
+
+/* 4 hardware channels, as defined in STAT0: COMB, CS2, CS1 and CS0. */
+#define SX9310_NUM_CHANNELS                            4
+#define SX9310_CHAN_ENABLED_MASK                       GENMASK(3, 0)
+
+struct sx9310_data {
+       /* Serialize access to registers and channel configuration */
+       struct mutex mutex;
+       struct i2c_client *client;
+       struct iio_trigger *trig;
+       struct regmap *regmap;
+       /*
+        * Last reading of the proximity status for each channel.
+        * We only send an event to user space when this changes.
+        */
+       bool prox_stat[SX9310_NUM_CHANNELS];
+       bool trigger_enabled;
+       __be16 buffer[SX9310_NUM_CHANNELS +
+                     4]; /* 64-bit data + 64-bit timestamp */
+       /* Remember enabled channels and sample rate during suspend. */
+       unsigned int suspend_ctrl0;
+       struct completion completion;
+       unsigned int chan_read, chan_event;
+       int channel_users[SX9310_NUM_CHANNELS];
+       int whoami;
+};
+
+static const struct iio_event_spec sx9310_events[] = {
+       {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_EITHER,
+               .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+       },
+};
+
+#define SX9310_NAMED_CHANNEL(idx, name)                                         \
+       {                                                                \
+               .type = IIO_PROXIMITY,                                   \
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),            \
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+               .indexed = 1,                                            \
+               .channel = idx,                                          \
+               .extend_name = name,                                     \
+               .address = SX9310_REG_DIFF_MSB,                          \
+               .event_spec = sx9310_events,                             \
+               .num_event_specs = ARRAY_SIZE(sx9310_events),            \
+               .scan_index = idx,                                       \
+               .scan_type = {                                           \
+                       .sign = 's',                                     \
+                       .realbits = 12,                                  \
+                       .storagebits = 16,                               \
+                       .endianness = IIO_BE,                            \
+               },                                                       \
+       }
+#define SX9310_CHANNEL(idx) SX9310_NAMED_CHANNEL(idx, NULL)
+
+static const struct iio_chan_spec sx9310_channels[] = {
+       SX9310_CHANNEL(0),                      /* CS0 */
+       SX9310_CHANNEL(1),                      /* CS1 */
+       SX9310_CHANNEL(2),                      /* CS2 */
+       SX9310_NAMED_CHANNEL(3, "comb"),        /* COMB */
+
+       IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+/*
+ * Each entry contains the integer part (val) and the fractional part, in micro
+ * seconds. It conforms to the IIO output IIO_VAL_INT_PLUS_MICRO.
+ */
+static const struct {
+       int val;
+       int val2;
+} sx9310_samp_freq_table[] = {
+       { 500, 0 }, /* 0000: Min (no idle time) */
+       { 66, 666666 }, /* 0001: 15 ms */
+       { 33, 333333 }, /* 0010: 30 ms (Typ.) */
+       { 22, 222222 }, /* 0011: 45 ms */
+       { 16, 666666 }, /* 0100: 60 ms */
+       { 11, 111111 }, /* 0101: 90 ms */
+       { 8, 333333 }, /* 0110: 120 ms */
+       { 5, 0 }, /* 0111: 200 ms */
+       { 2, 500000 }, /* 1000: 400 ms */
+       { 1, 666666 }, /* 1001: 600 ms */
+       { 1, 250000 }, /* 1010: 800 ms */
+       { 1, 0 }, /* 1011: 1 s */
+       { 0, 500000 }, /* 1100: 2 s */
+       { 0, 333333 }, /* 1101: 3 s */
+       { 0, 250000 }, /* 1110: 4 s */
+       { 0, 200000 }, /* 1111: 5 s */
+};
+static const unsigned int sx9310_scan_period_table[] = {
+       2,   15,  30,  45,   60,   90,   120,  200,
+       400, 600, 800, 1000, 2000, 3000, 4000, 5000,
+};
+
+static ssize_t sx9310_show_samp_freq_avail(struct device *dev,
+                                          struct device_attribute *attr,
+                                          char *buf)
+{
+       size_t len = 0;
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
+               len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%d ",
+                                sx9310_samp_freq_table[i].val,
+                                sx9310_samp_freq_table[i].val2);
+       buf[len - 1] = '\n';
+       return len;
+}
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sx9310_show_samp_freq_avail);
+
+static const struct regmap_range sx9310_writable_reg_ranges[] = {
+       regmap_reg_range(SX9310_REG_IRQ_MSK, SX9310_REG_IRQ_FUNC),
+       regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
+       regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
+       regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SENSOR_SEL),
+       regmap_reg_range(SX9310_REG_OFFSET_MSB, SX9310_REG_OFFSET_LSB),
+       regmap_reg_range(SX9310_REG_PAUSE, SX9310_REG_PAUSE),
+       regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
+};
+
+static const struct regmap_access_table sx9310_writeable_regs = {
+       .yes_ranges = sx9310_writable_reg_ranges,
+       .n_yes_ranges = ARRAY_SIZE(sx9310_writable_reg_ranges),
+};
+
+static const struct regmap_range sx9310_readable_reg_ranges[] = {
+       regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_IRQ_FUNC),
+       regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
+       regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
+       regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SAR_LSB),
+       regmap_reg_range(SX9310_REG_I2CADDR, SX9310_REG_WHOAMI),
+       regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
+};
+
+static const struct regmap_access_table sx9310_readable_regs = {
+       .yes_ranges = sx9310_readable_reg_ranges,
+       .n_yes_ranges = ARRAY_SIZE(sx9310_readable_reg_ranges),
+};
+
+static const struct regmap_range sx9310_volatile_reg_ranges[] = {
+       regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_STAT1),
+       regmap_reg_range(SX9310_REG_USE_MSB, SX9310_REG_DIFF_LSB),
+       regmap_reg_range(SX9310_REG_SAR_MSB, SX9310_REG_SAR_LSB),
+       regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
+};
+
+static const struct regmap_access_table sx9310_volatile_regs = {
+       .yes_ranges = sx9310_volatile_reg_ranges,
+       .n_yes_ranges = ARRAY_SIZE(sx9310_volatile_reg_ranges),
+};
+
+static const struct regmap_config sx9310_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+
+       .max_register = SX9310_REG_RESET,
+       .cache_type = REGCACHE_RBTREE,
+
+       .wr_table = &sx9310_writeable_regs,
+       .rd_table = &sx9310_readable_regs,
+       .volatile_table = &sx9310_volatile_regs,
+};
+
+static int sx9310_update_chan_en(struct sx9310_data *data,
+                                unsigned int chan_read,
+                                unsigned int chan_event)
+{
+       int ret;
+
+       if ((data->chan_read | data->chan_event) != (chan_read | chan_event)) {
+               ret = regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL0,
+                                        SX9310_CHAN_ENABLED_MASK,
+                                        chan_read | chan_event);
+               if (ret)
+                       return ret;
+       }
+       data->chan_read = chan_read;
+       data->chan_event = chan_event;
+       return 0;
+}
+
+static int sx9310_get_read_channel(struct sx9310_data *data, int channel)
+{
+       return sx9310_update_chan_en(data, data->chan_read | BIT(channel),
+                                    data->chan_event);
+}
+
+static int sx9310_put_read_channel(struct sx9310_data *data, int channel)
+{
+       return sx9310_update_chan_en(data, data->chan_read & ~BIT(channel),
+                                    data->chan_event);
+}
+
+static int sx9310_get_event_channel(struct sx9310_data *data, int channel)
+{
+       return sx9310_update_chan_en(data, data->chan_read,
+                                    data->chan_event | BIT(channel));
+}
+
+static int sx9310_put_event_channel(struct sx9310_data *data, int channel)
+{
+       return sx9310_update_chan_en(data, data->chan_read,
+                                    data->chan_event & ~BIT(channel));
+}
+
+static int sx9310_enable_irq(struct sx9310_data *data, unsigned int irq)
+{
+       return regmap_update_bits(data->regmap, SX9310_REG_IRQ_MSK, irq, irq);
+}
+
+static int sx9310_disable_irq(struct sx9310_data *data, unsigned int irq)
+{
+       return regmap_update_bits(data->regmap, SX9310_REG_IRQ_MSK, irq, 0);
+}
+
+static int sx9310_read_prox_data(struct sx9310_data *data,
+                                const struct iio_chan_spec *chan, __be16 *val)
+{
+       int ret;
+
+       ret = regmap_write(data->regmap, SX9310_REG_SENSOR_SEL, chan->channel);
+       if (ret < 0)
+               return ret;
+
+       return regmap_bulk_read(data->regmap, chan->address, val, 2);
+}
+
+/*
+ * If we have no interrupt support, we have to wait for a scan period
+ * after enabling a channel to get a result.
+ */
+static int sx9310_wait_for_sample(struct sx9310_data *data)
+{
+       int ret;
+       unsigned int val;
+
+       ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &val);
+       if (ret < 0)
+               return ret;
+
+       val = (val & SX9310_SCAN_PERIOD_MASK) >> SX9310_SCAN_PERIOD_SHIFT;
+
+       msleep(sx9310_scan_period_table[val]);
+
+       return 0;
+}
+
+static int sx9310_read_proximity(struct sx9310_data *data,
+                                const struct iio_chan_spec *chan, int *val)
+{
+       int ret = 0;
+       __be16 rawval;
+
+       mutex_lock(&data->mutex);
+
+       ret = sx9310_get_read_channel(data, chan->channel);
+       if (ret < 0)
+               goto out;
+
+       ret = sx9310_enable_irq(data, SX9310_CONVDONE_IRQ);
+       if (ret < 0)
+               goto out_put_channel;
+
+       mutex_unlock(&data->mutex);
+
+       if (data->client->irq > 0) {
+               ret = wait_for_completion_interruptible(&data->completion);
+               reinit_completion(&data->completion);
+       } else {
+               ret = sx9310_wait_for_sample(data);
+       }
+
+       mutex_lock(&data->mutex);
+
+       if (ret < 0)
+               goto out_disable_irq;
+
+       ret = sx9310_read_prox_data(data, chan, &rawval);
+       if (ret < 0)
+               goto out_disable_irq;
+
+       *val = sign_extend32(be16_to_cpu(rawval),
+                            (chan->address == SX9310_REG_DIFF_MSB ? 11 : 15));
+
+       ret = sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
+       if (ret < 0)
+               goto out_put_channel;
+
+       ret = sx9310_put_read_channel(data, chan->channel);
+       if (ret < 0)
+               goto out;
+
+       mutex_unlock(&data->mutex);
+
+       return IIO_VAL_INT;
+
+out_disable_irq:
+       sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
+out_put_channel:
+       sx9310_put_read_channel(data, chan->channel);
+out:
+       mutex_unlock(&data->mutex);
+
+       return ret;
+}
+
+static int sx9310_read_samp_freq(struct sx9310_data *data, int *val, int *val2)
+{
+       unsigned int regval;
+       int ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &regval);
+
+       if (ret < 0)
+               return ret;
+
+       regval = (regval & SX9310_SCAN_PERIOD_MASK) >> SX9310_SCAN_PERIOD_SHIFT;
+       *val = sx9310_samp_freq_table[regval].val;
+       *val2 = sx9310_samp_freq_table[regval].val2;
+
+       return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int sx9310_read_raw(struct iio_dev *indio_dev,
+                          const struct iio_chan_spec *chan, int *val,
+                          int *val2, long mask)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret;
+
+       if (chan->type != IIO_PROXIMITY)
+               return -EINVAL;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               ret = iio_device_claim_direct_mode(indio_dev);
+               if (ret)
+                       return ret;
+
+               ret = sx9310_read_proximity(data, chan, val);
+               iio_device_release_direct_mode(indio_dev);
+               return ret;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               return sx9310_read_samp_freq(data, val, val2);
+       default:
+               return -EINVAL;
+       }
+}
+
+static int sx9310_set_samp_freq(struct sx9310_data *data, int val, int val2)
+{
+       int i, ret;
+
+       for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
+               if (val == sx9310_samp_freq_table[i].val &&
+                   val2 == sx9310_samp_freq_table[i].val2)
+                       break;
+
+       if (i == ARRAY_SIZE(sx9310_samp_freq_table))
+               return -EINVAL;
+
+       mutex_lock(&data->mutex);
+
+       ret = regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL0,
+                                SX9310_SCAN_PERIOD_MASK,
+                                i << SX9310_SCAN_PERIOD_SHIFT);
+
+       mutex_unlock(&data->mutex);
+
+       return ret;
+}
+
+static int sx9310_write_raw(struct iio_dev *indio_dev,
+                           const struct iio_chan_spec *chan, int val, int val2,
+                           long mask)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+
+       if (chan->type != IIO_PROXIMITY)
+               return -EINVAL;
+
+       if (mask != IIO_CHAN_INFO_SAMP_FREQ)
+               return -EINVAL;
+
+       return sx9310_set_samp_freq(data, val, val2);
+}
+
+static irqreturn_t sx9310_irq_handler(int irq, void *private)
+{
+       struct iio_dev *indio_dev = private;
+       struct sx9310_data *data = iio_priv(indio_dev);
+
+       if (data->trigger_enabled)
+               iio_trigger_poll(data->trig);
+
+       /*
+        * Even if no event is enabled, we need to wake the thread to
+        * clear the interrupt state by reading SX9310_REG_IRQ_SRC.  It
+        * is not possible to do that here because regmap_read takes a
+        * mutex.
+        */
+       return IRQ_WAKE_THREAD;
+}
+
+static void sx9310_push_events(struct iio_dev *indio_dev)
+{
+       int ret;
+       unsigned int val, chan;
+       struct sx9310_data *data = iio_priv(indio_dev);
+       s64 timestamp = iio_get_time_ns(indio_dev);
+
+       /* Read proximity state on all channels */
+       ret = regmap_read(data->regmap, SX9310_REG_STAT0, &val);
+       if (ret < 0) {
+               dev_err(&data->client->dev, "i2c transfer error in irq\n");
+               return;
+       }
+
+       for (chan = 0; chan < SX9310_NUM_CHANNELS; chan++) {
+               int dir;
+               u64 ev;
+               bool new_prox = val & BIT(chan);
+
+               if (!(data->chan_event & BIT(chan)))
+                       continue;
+               if (new_prox == data->prox_stat[chan])
+                       /* No change on this channel. */
+                       continue;
+
+               dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
+               ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
+                                         IIO_EV_TYPE_THRESH, dir);
+
+               iio_push_event(indio_dev, ev, timestamp);
+               data->prox_stat[chan] = new_prox;
+       }
+}
+
+static irqreturn_t sx9310_irq_thread_handler(int irq, void *private)
+{
+       struct iio_dev *indio_dev = private;
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret;
+       unsigned int val;
+
+       mutex_lock(&data->mutex);
+
+       ret = regmap_read(data->regmap, SX9310_REG_IRQ_SRC, &val);
+       if (ret < 0) {
+               dev_err(&data->client->dev, "i2c transfer error in irq\n");
+               goto out;
+       }
+
+       if (val & SX9310_EVENT_IRQ)
+               sx9310_push_events(indio_dev);
+
+       if (val & SX9310_CONVDONE_IRQ)
+               complete(&data->completion);
+
+out:
+       mutex_unlock(&data->mutex);
+
+       return IRQ_HANDLED;
+}
+
+static int sx9310_read_event_config(struct iio_dev *indio_dev,
+                                   const struct iio_chan_spec *chan,
+                                   enum iio_event_type type,
+                                   enum iio_event_direction dir)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+
+       return !!(data->chan_event & BIT(chan->channel));
+}
+
+static int sx9310_write_event_config(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir, int state)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret;
+
+       /* If the state hasn't changed, there's nothing to do. */
+       if (!!(data->chan_event & BIT(chan->channel)) == state)
+               return 0;
+
+       mutex_lock(&data->mutex);
+       if (state) {
+               ret = sx9310_get_event_channel(data, chan->channel);
+               if (ret < 0)
+                       goto out_unlock;
+               if (!(data->chan_event & ~BIT(chan->channel))) {
+                       ret = sx9310_enable_irq(data, SX9310_EVENT_IRQ);
+                       if (ret < 0)
+                               sx9310_put_event_channel(data, chan->channel);
+               }
+       } else {
+               ret = sx9310_put_event_channel(data, chan->channel);
+               if (ret < 0)
+                       goto out_unlock;
+               if (!data->chan_event) {
+                       ret = sx9310_disable_irq(data, SX9310_EVENT_IRQ);
+                       if (ret < 0)
+                               sx9310_get_event_channel(data, chan->channel);
+               }
+       }
+
+out_unlock:
+       mutex_unlock(&data->mutex);
+       return ret;
+}
+
+static struct attribute *sx9310_attributes[] = {
+       &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group sx9310_attribute_group = {
+       .attrs = sx9310_attributes,
+};
+
+static const struct iio_info sx9310_info = {
+       .attrs = &sx9310_attribute_group,
+       .read_raw = sx9310_read_raw,
+       .write_raw = sx9310_write_raw,
+       .read_event_config = sx9310_read_event_config,
+       .write_event_config = sx9310_write_event_config,
+};
+
+static int sx9310_set_trigger_state(struct iio_trigger *trig, bool state)
+{
+       struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret = 0;
+
+       mutex_lock(&data->mutex);
+
+       if (state)
+               ret = sx9310_enable_irq(data, SX9310_CONVDONE_IRQ);
+       else if (!data->chan_read)
+               ret = sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
+       if (ret < 0)
+               goto out;
+
+       data->trigger_enabled = state;
+
+out:
+       mutex_unlock(&data->mutex);
+
+       return ret;
+}
+
+static const struct iio_trigger_ops sx9310_trigger_ops = {
+       .set_trigger_state = sx9310_set_trigger_state,
+};
+
+static irqreturn_t sx9310_trigger_handler(int irq, void *private)
+{
+       struct iio_poll_func *pf = private;
+       struct iio_dev *indio_dev = pf->indio_dev;
+       struct sx9310_data *data = iio_priv(indio_dev);
+       __be16 val;
+       int bit, ret, i = 0;
+
+       mutex_lock(&data->mutex);
+
+       for_each_set_bit(bit, indio_dev->active_scan_mask,
+                        indio_dev->masklength) {
+               ret = sx9310_read_prox_data(data, &indio_dev->channels[bit],
+                                           &val);
+               if (ret < 0)
+                       goto out;
+
+               data->buffer[i++] = val;
+       }
+
+       iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+                                          pf->timestamp);
+
+out:
+       mutex_unlock(&data->mutex);
+
+       iio_trigger_notify_done(indio_dev->trig);
+
+       return IRQ_HANDLED;
+}
+
+static int sx9310_buffer_preenable(struct iio_dev *indio_dev)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       unsigned int channels = 0;
+       int bit, ret;
+
+       mutex_lock(&data->mutex);
+       for_each_set_bit(bit, indio_dev->active_scan_mask,
+                        indio_dev->masklength)
+               channels |= BIT(indio_dev->channels[bit].channel);
+
+       ret = sx9310_update_chan_en(data, channels, data->chan_event);
+       mutex_unlock(&data->mutex);
+       return ret;
+}
+
+static int sx9310_buffer_postdisable(struct iio_dev *indio_dev)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&data->mutex);
+       ret = sx9310_update_chan_en(data, 0, data->chan_event);
+       mutex_unlock(&data->mutex);
+       return ret;
+}
+
+static const struct iio_buffer_setup_ops sx9310_buffer_setup_ops = {
+       .preenable = sx9310_buffer_preenable,
+       .postenable = iio_triggered_buffer_postenable,
+       .predisable = iio_triggered_buffer_predisable,
+       .postdisable = sx9310_buffer_postdisable,
+};
+
+struct sx9310_reg_default {
+       u8 reg;
+       u8 def;
+};
+
+#define SX_INIT(_reg, _def)                    \
+       {                                       \
+               .reg = SX9310_REG_##_reg,       \
+               .def = _def,                    \
+       }
+
+static const struct sx9310_reg_default sx9310_default_regs[] = {
+       SX_INIT(IRQ_MSK, 0x00),
+       SX_INIT(IRQ_FUNC, 0x00),
+       /*
+        * The lower 4 bits should not be set as it enable sensors measurements.
+        * Turning the detection on before the configuration values are set to
+        * good values can cause the device to return erroneous readings.
+        */
+       SX_INIT(PROX_CTRL0, SX9310_REG_PROX_CTRL0_PROXSTAT2),
+       SX_INIT(PROX_CTRL1, 0x00),
+       SX_INIT(PROX_CTRL2, SX9310_REG_PROX_CTRL2_COMBMODE_ALL |
+                           SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC),
+       SX_INIT(PROX_CTRL3, SX9310_REG_PROX_CTRL3_GAIN0_X8 |
+                           SX9310_REG_PROX_CTRL3_GAIN12_X4),
+       SX_INIT(PROX_CTRL4, SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST),
+       SX_INIT(PROX_CTRL5, SX9310_REG_PROX_CTRL5_RANGE_SMALL |
+                           SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1 |
+                           SX9310_REG_PROX_CTRL5_RAWFILT_1P25),
+       SX_INIT(PROX_CTRL6, SX9310_REG_PROX_CTRL6_COMP_COMMON),
+       SX_INIT(PROX_CTRL7, SX9310_REG_PROX_CTRL7_AVGNEGFILT_2 |
+                           SX9310_REG_PROX_CTRL7_AVGPOSFILT_512),
+       SX_INIT(PROX_CTRL8, SX9310_REG_PROX_CTRL8_9_PTHRESH_96 |
+                           SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500),
+       SX_INIT(PROX_CTRL9, SX9310_REG_PROX_CTRL8_9_PTHRESH12_28 |
+                           SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900),
+       SX_INIT(PROX_CTRL10, SX9310_REG_PROX_CTRL10_HYST_6PCT |
+                            SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_8 |
+                            SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_8),
+       SX_INIT(PROX_CTRL11, 0x00),
+       SX_INIT(PROX_CTRL12, 0x00),
+       SX_INIT(PROX_CTRL13, 0x00),
+       SX_INIT(PROX_CTRL14, 0x00),
+       SX_INIT(PROX_CTRL15, 0x00),
+       SX_INIT(PROX_CTRL16, 0x00),
+       SX_INIT(PROX_CTRL17, 0x00),
+       SX_INIT(PROX_CTRL18, 0x00),
+       SX_INIT(PROX_CTRL19, 0x00),
+       SX_INIT(SAR_CTRL0, SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES |
+                          SX9310_REG_SAR_CTRL0_SARHYST_8),
+       SX_INIT(SAR_CTRL1, SX9310_REG_SAR_CTRL1_SLOPE(10781250)),
+       SX_INIT(SAR_CTRL2, SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT),
+};
+
+/* Activate all channels and perform an initial compensation. */
+static int sx9310_init_compensation(struct iio_dev *indio_dev)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int i, ret;
+       unsigned int val;
+       unsigned int ctrl0;
+
+       ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &ctrl0);
+       if (ret < 0)
+               return ret;
+
+       /* run the compensation phase on all channels */
+       ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
+                          ctrl0 | SX9310_REG_PROX_CTRL0_EN_MASK);
+       if (ret < 0)
+               return ret;
+
+       for (i = 100; i >= 0; i--) {
+               msleep(20);
+               ret = regmap_read(data->regmap, SX9310_REG_STAT1, &val);
+               if (ret < 0)
+                       goto out;
+               if (!(val & SX9310_COMPSTAT_MASK))
+                       break;
+       }
+
+       if (i < 0) {
+               dev_err(&data->client->dev,
+                       "initial compensation timed out: 0x%02x", val);
+               ret = -ETIMEDOUT;
+       }
+
+out:
+       regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
+       return ret;
+}
+
+static int sx9310_init_device(struct iio_dev *indio_dev)
+{
+       struct sx9310_data *data = iio_priv(indio_dev);
+       const struct sx9310_reg_default *initval;
+       int ret;
+       unsigned int i, val;
+
+       ret = regmap_write(data->regmap, SX9310_REG_RESET, SX9310_SOFT_RESET);
+       if (ret < 0)
+               return ret;
+
+       usleep_range(1000, 2000); /* power-up time is ~1ms. */
+
+       /* Clear reset interrupt state by reading SX9310_REG_IRQ_SRC. */
+       ret = regmap_read(data->regmap, SX9310_REG_IRQ_SRC, &val);
+       if (ret < 0)
+               return ret;
+
+       /* Program some sane defaults. */
+       for (i = 0; i < ARRAY_SIZE(sx9310_default_regs); i++) {
+               initval = &sx9310_default_regs[i];
+               ret = regmap_write(data->regmap, initval->reg, initval->def);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return sx9310_init_compensation(indio_dev);
+}
+
+static int sx9310_set_indio_dev_name(struct device *dev,
+                                    struct iio_dev *indio_dev,
+                                    const struct i2c_device_id *id, int whoami)
+{
+       const struct acpi_device_id *acpi_id;
+
+       /* id will be NULL when enumerated via ACPI */
+       if (id) {
+               if (id->driver_data != whoami)
+                       dev_err(dev, "WHOAMI does not match i2c_device_id: %s",
+                               id->name);
+       } else if (ACPI_HANDLE(dev)) {
+               acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
+               if (!acpi_id)
+                       return -ENODEV;
+               if (acpi_id->driver_data != whoami)
+                       dev_err(dev, "WHOAMI does not match acpi_device_id: %s",
+                               acpi_id->id);
+       } else
+               return -ENODEV;
+
+       switch (whoami) {
+       case SX9310_WHOAMI_VALUE:
+               indio_dev->name = "sx9310";
+               break;
+       case SX9311_WHOAMI_VALUE:
+               indio_dev->name = "sx9311";
+               break;
+       default:
+               dev_err(dev, "unexpected WHOAMI response: %u", whoami);
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static int sx9310_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       int ret;
+       struct iio_dev *indio_dev;
+       struct sx9310_data *data;
+
+       indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+       if (indio_dev == NULL)
+               return -ENOMEM;
+
+       data = iio_priv(indio_dev);
+       data->client = client;
+       mutex_init(&data->mutex);
+       init_completion(&data->completion);
+
+       data->regmap = devm_regmap_init_i2c(client, &sx9310_regmap_config);
+       if (IS_ERR(data->regmap))
+               return PTR_ERR(data->regmap);
+
+       ret = regmap_read(data->regmap, SX9310_REG_WHOAMI, &data->whoami);
+       if (ret < 0) {
+               dev_err(&client->dev, "error in reading WHOAMI register: %d",
+                       ret);
+               return ret;
+       }
+
+       ret = sx9310_set_indio_dev_name(&client->dev, indio_dev, id,
+                                       data->whoami);
+       if (ret < 0)
+               return ret;
+
+       ACPI_COMPANION_SET(&indio_dev->dev, ACPI_COMPANION(&client->dev));
+       indio_dev->dev.parent = &client->dev;
+       indio_dev->channels = sx9310_channels;
+       indio_dev->num_channels = ARRAY_SIZE(sx9310_channels);
+       indio_dev->info = &sx9310_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       i2c_set_clientdata(client, indio_dev);
+
+       ret = sx9310_init_device(indio_dev);
+       if (ret < 0)
+               return ret;
+
+       if (client->irq) {
+               ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                               sx9310_irq_handler,
+                                               sx9310_irq_thread_handler,
+                                               IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                               "sx9310_event", indio_dev);
+               if (ret < 0)
+                       return ret;
+
+               data->trig =
+                       devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
+                                              indio_dev->name, indio_dev->id);
+               if (!data->trig)
+                       return -ENOMEM;
+
+               data->trig->dev.parent = &client->dev;
+               data->trig->ops = &sx9310_trigger_ops;
+               iio_trigger_set_drvdata(data->trig, indio_dev);
+
+               ret = devm_iio_trigger_register(&client->dev, data->trig);
+               if (ret)
+                       return ret;
+       }
+
+       ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
+                                             iio_pollfunc_store_time,
+                                             sx9310_trigger_handler,
+                                             &sx9310_buffer_setup_ops);
+       if (ret < 0)
+               return ret;
+
+       return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int __maybe_unused sx9310_suspend(struct device *dev)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+       struct sx9310_data *data = iio_priv(indio_dev);
+       u8 ctrl0;
+       int ret;
+
+       disable_irq_nosync(data->client->irq);
+
+       mutex_lock(&data->mutex);
+       ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0,
+                         &data->suspend_ctrl0);
+
+       if (ret)
+               goto out;
+
+       ctrl0 = data->suspend_ctrl0 & ~SX9310_REG_PROX_CTRL0_EN_MASK;
+       ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
+       if (ret)
+               goto out;
+
+       ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 0);
+
+out:
+       mutex_unlock(&data->mutex);
+       return ret;
+}
+
+static int __maybe_unused sx9310_resume(struct device *dev)
+{
+       struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+       struct sx9310_data *data = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&data->mutex);
+       ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 1);
+       if (ret)
+               goto out;
+
+       ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
+                          data->suspend_ctrl0);
+
+out:
+       mutex_unlock(&data->mutex);
+
+       enable_irq(data->client->irq);
+
+       return ret;
+}
+
+static const struct dev_pm_ops sx9310_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(sx9310_suspend, sx9310_resume)
+};
+
+static const struct acpi_device_id sx9310_acpi_match[] = {
+       { "STH9310", SX9310_WHOAMI_VALUE },
+       { "STH9311", SX9311_WHOAMI_VALUE },
+       {},
+};
+MODULE_DEVICE_TABLE(acpi, sx9310_acpi_match);
+
+static const struct of_device_id sx9310_of_match[] = {
+       { .compatible = "semtech,sx9310" },
+       { .compatible = "semtech,sx9311" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, sx9310_of_match);
+
+static const struct i2c_device_id sx9310_id[] = {
+       { "sx9310", SX9310_WHOAMI_VALUE },
+       { "sx9311", SX9311_WHOAMI_VALUE },
+       {},
+};
+MODULE_DEVICE_TABLE(i2c, sx9310_id);
+
+static struct i2c_driver sx9310_driver = {
+       .driver = {
+               .name   = "sx9310",
+               .acpi_match_table = ACPI_PTR(sx9310_acpi_match),
+               .of_match_table = of_match_ptr(sx9310_of_match),
+               .pm = &sx9310_pm_ops,
+       },
+       .probe          = sx9310_probe,
+       .id_table       = sx9310_id,
+};
+module_i2c_driver(sx9310_driver);
+
+MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
+MODULE_AUTHOR("Daniel Campello <campello@chromium.org>");
+MODULE_DESCRIPTION("Driver for Semtech SX9310/SX9311 proximity sensor");
+MODULE_LICENSE("GPL v2");