[PATCH 3/3] iio: Add PAT9125 optical tracker sensor
From: Alexandre Mergnat
Date: Fri Apr 05 2019 - 05:35:02 EST
This adds support for PixArt Imagingâs miniature low power
optical navigation chip using LASER light source
enabling digital surface tracking.
This IIO driver allow to read delta position on 2 axis (X and Y).
The values can be taken through ponctual "read_raw" which will issue
a read in the device registers to return the deltas or subscribe
to the data buffer feed automaticaly by a new value using a
trigger gpio. The buffer payload is: |16 bits delta X|16 bits delta Y|timestamp|.
The possible I2C adresses are 0x73, 0x75 and 0x79.
Unfortunately, the device configuration must be hardcoded in the initialization
function and can't be changed "on-the-fly" in user space due to the lack of
configuration interface.
The "ot" directory is added to coutain Optical Tracker drivers.
Signed-off-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
---
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/ot/Kconfig | 16 ++
drivers/iio/ot/Makefile | 6 +
drivers/iio/ot/pat9125.c | 407 +++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 431 insertions(+)
create mode 100644 drivers/iio/ot/Kconfig
create mode 100644 drivers/iio/ot/Makefile
create mode 100644 drivers/iio/ot/pat9125.c
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index d08aeb4..bdf1bd0 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -86,6 +86,7 @@ source "drivers/iio/light/Kconfig"
source "drivers/iio/magnetometer/Kconfig"
source "drivers/iio/multiplexer/Kconfig"
source "drivers/iio/orientation/Kconfig"
+source "drivers/iio/ot/Kconfig"
if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index cb59932..fdda2e1 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -32,6 +32,7 @@ obj-y += light/
obj-y += magnetometer/
obj-y += multiplexer/
obj-y += orientation/
+obj-y += ot/
obj-y += potentiometer/
obj-y += potentiostat/
obj-y += pressure/
diff --git a/drivers/iio/ot/Kconfig b/drivers/iio/ot/Kconfig
new file mode 100644
index 0000000..3d17fda
--- /dev/null
+++ b/drivers/iio/ot/Kconfig
@@ -0,0 +1,16 @@
+#
+# Optical tracker sensors
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Optical tracker sensors"
+
+config PAT9125
+ tristate "Optical tracker PAT9125 I2C driver"
+ depends on I2C
+ select IIO_BUFFER
+ help
+ Say yes here to build support for PAT9125 optical tracker
+ sensors.
+
+endmenu
diff --git a/drivers/iio/ot/Makefile b/drivers/iio/ot/Makefile
new file mode 100644
index 0000000..cf29491
--- /dev/null
+++ b/drivers/iio/ot/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for industrial I/O Optical tracker sensor drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_PAT9125) += pat9125.o
diff --git a/drivers/iio/ot/pat9125.c b/drivers/iio/ot/pat9125.c
new file mode 100644
index 0000000..f416bfa
--- /dev/null
+++ b/drivers/iio/ot/pat9125.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: (GPL-2.0)
+/*
+ * Copyright (C) 2018 BayLibre, SAS
+ * Author: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/kfifo_buf.h>
+
+/* I2C Address function to ID pin*/
+#define PAT9125_I2C_ADDR_HI 0x73
+#define PAT9125_I2C_ADDR_LO 0x75
+#define PAT9125_I2C_ADDR_NC 0x79
+
+/* Registers */
+#define PAT9125_PRD_ID1_REG 0x00
+#define PAT9125_PRD_ID2_REG 0x01
+#define PAT9125_MOTION_STATUS_REG 0x02
+#define PAT9125_DELTA_X_LO_REG 0x03
+#define PAT9125_DELTA_Y_LO_REG 0x04
+#define PAT9125_OP_MODE_REG 0x05
+#define PAT9125_CONFIG_REG 0x06
+#define PAT9125_WRITE_PROTEC_REG 0x09
+#define PAT9125_SLEEP1_REG 0x0A
+#define PAT9125_SLEEP2_REG 0x0B
+#define PAT9125_RES_X_REG 0x0D
+#define PAT9125_RES_Y_REG 0x0E
+#define PAT9125_DELTA_XY_HI_REG 0x12
+#define PAT9125_SHUTER_REG 0x14
+#define PAT9125_FRAME_AVG_REG 0x17
+#define PAT9125_ORIENTATION_REG 0x19
+
+/* Masks */
+#define PAT9125_VALID_MOTION_DATA_MASK 0x80
+#define PAT9125_RESET_MASK 0x80
+
+/* Registers' values */
+#define PAT9125_SENSOR_ID_VAL 0x31
+#define PAT9125_DISABLE_WRITE_PROTECT_VAL 0x5A
+#define PAT9125_ENABLE_WRITE_PROTECT_VAL 0x00
+#define PAT9125_CPI_RESOLUTION_X_VAL 0x65
+#define PAT9125_CPI_RESOLUTION_Y_VAL 0xFF
+
+/* Default Value of sampled value size */
+#define PAT9125_SAMPLED_VAL_BIT_SIZE 12
+#define PAT9125_SAMPLED_VAL_BYTE_SIZE 2 /* 12 bits by default */
+#define PAT9125_TIMESTAMP_BYTE_SIZE 8 /* 64 bits */
+#define PAT9125_PAYLOAD_BYTE_SIZE \
+ (2 * PAT9125_SAMPLED_VAL_BYTE_SIZE + PAT9125_TIMESTAMP_BYTE_SIZE)
+#define PAT9125_REALBITS_XY_VAL \
+ (2 * PAT9125_SAMPLED_VAL_BIT_SIZE)
+#define PAT9125_STORAGEBITS_XY_VAL \
+ (2 * PAT9125_SAMPLED_VAL_BYTE_SIZE)
+
+struct pat9125_data {
+ struct i2c_client *client;
+ struct regmap *regmap;
+ s16 delta_x;
+ s16 delta_y;
+};
+
+static const struct iio_event_spec pat9125_event = {
+ .type = IIO_EV_TYPE_THRESH,
+ .dir = IIO_EV_DIR_RISING,
+ .mask_separate = BIT(IIO_EV_INFO_VALUE),
+};
+
+static const struct iio_chan_spec pat9125_channels[] = {
+ {
+ .type = IIO_DISTANCE,
+ .modified = 1,
+ .channel2 = IIO_MOD_X_AND_Y,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .address = 0,
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 's', \
+ .realbits = 24, \
+ .storagebits = 32, \
+ .shift = 8, \
+ .endianness = IIO_BE, \
+ },
+ .event_spec = &pat9125_event,
+ .num_event_specs = 1,
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int pat9125_read_delta(struct pat9125_data *data)
+{
+ struct regmap *regmap = data->regmap;
+ int status = 0;
+ int val_x = 0;
+ int val_y = 0;
+ int val_xy = 0;
+ int r;
+
+ r = regmap_read(regmap, PAT9125_MOTION_STATUS_REG, &status);
+ if (r < 0)
+ return r;
+
+ /* Check motion bit in bit7 */
+ if (status & PAT9125_VALID_MOTION_DATA_MASK) {
+ r = regmap_read(regmap, PAT9125_DELTA_X_LO_REG, &val_x);
+ if (r < 0)
+ return r;
+
+ r = regmap_read(regmap, PAT9125_DELTA_Y_LO_REG, &val_y);
+ if (r < 0)
+ return r;
+
+ r = regmap_read(regmap, PAT9125_DELTA_XY_HI_REG, &val_xy);
+ if (r < 0)
+ return r;
+
+ data->delta_x = val_x | ((val_xy << 4) & 0xF00);
+ data->delta_y = val_y | ((val_xy << 8) & 0xF00);
+
+ if (data->delta_x & 0x800)
+ data->delta_x |= 0xF000;
+
+ if (data->delta_y & 0x800)
+ data->delta_y |= 0xF000;
+ }
+
+ return 0;
+}
+
+/**
+ * pat9125_read_raw() - Sample and return the value(s)
+ * function to the associated channel info enum.
+ **/
+static int pat9125_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct pat9125_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = pat9125_read_delta(data);
+ if (ret)
+ return ret;
+
+ *val = data->delta_x;
+ *val2 = data->delta_y;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * pat9125_read_event_value() - return last sampled value.
+ **/
+static int pat9125_read_event_value(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ enum iio_event_type type,
+ enum iio_event_direction dir,
+ enum iio_event_info info,
+ int *val,
+ int *val2)
+{
+ struct pat9125_data *data = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_EV_INFO_VALUE:
+ val[0] = data->delta_x;
+ val[1] = data->delta_y;
+ *val2 = 2;
+ return IIO_VAL_INT_MULTIPLE;
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * pat9125_event_handler() - handling ring and non ring events
+ * @irq: The irq being handled.
+ * @private: struct iio_device pointer for the device.
+ *
+ */
+static irqreturn_t pat9125_event_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct pat9125_data *data = iio_priv(indio_dev);
+ int ret = 0;
+ u8 *payload;
+ s64 last_timestamp = iio_get_time_ns(indio_dev);
+
+ payload = kmalloc(sizeof(s64) + 2 *
+ PAT9125_SAMPLED_VAL_BYTE_SIZE, GFP_KERNEL);
+
+ ret = pat9125_read_delta(data);
+ if (ret)
+ return ret;
+ memcpy(&payload[0], &data->delta_x, 2);
+ memcpy(&payload[2], &data->delta_y, 2);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, payload, last_timestamp);
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_DISTANCE,
+ 0,
+ IIO_MOD_X_AND_Y,
+ IIO_EV_TYPE_THRESH,
+ IIO_EV_DIR_RISING),
+ last_timestamp);
+
+ return IRQ_HANDLED;
+}
+
+static int pat9125_configure_ring(struct iio_dev *indio_dev)
+{
+ struct iio_buffer *buffer;
+ struct pat9125_data *data = iio_priv(indio_dev);
+
+ buffer = devm_iio_kfifo_allocate(&data->client->dev);
+ if (!buffer)
+ return -ENOMEM;
+
+ iio_device_attach_buffer(indio_dev, buffer);
+ indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
+
+ return 0;
+}
+
+static const struct regmap_config pat9125_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static const struct iio_info pat9125_info = {
+ .read_raw = pat9125_read_raw,
+ .read_event_value = &pat9125_read_event_value,
+};
+
+static int pat9125_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct pat9125_data *data;
+ struct iio_dev *indio_dev;
+ int r, sensor_pid;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ dev_err(&client->dev, "IIO device allocation failed");
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->name = id->name;
+ indio_dev->channels = pat9125_channels;
+ indio_dev->num_channels = ARRAY_SIZE(pat9125_channels);
+ indio_dev->info = &pat9125_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ r = pat9125_configure_ring(indio_dev);
+ if (r < 0) {
+ dev_err(&client->dev, "FIFO buffer allocation failed");
+ return r;
+ }
+
+ data->regmap = devm_regmap_init_i2c(client, &pat9125_regmap_config);
+ if (IS_ERR(data->regmap)) {
+ dev_err(&client->dev,
+ "regmap init failed %ld",
+ PTR_ERR(data->regmap));
+ return PTR_ERR(data->regmap);
+ }
+
+ /* Check device ID */
+ r = regmap_read(data->regmap, PAT9125_PRD_ID1_REG, &sensor_pid);
+ if (r < 0)
+ goto reg_access_fail;
+ if (sensor_pid != PAT9125_SENSOR_ID_VAL)
+ return -ENODEV;
+
+ /* Software reset (i.e. set bit7 to 1).
+ * It will reset to 0 automatically
+ */
+ r = regmap_write_bits(data->regmap,
+ PAT9125_CONFIG_REG,
+ PAT9125_RESET_MASK,
+ 1);
+ if (r < 0)
+ goto reg_access_fail;
+
+ /* Delay 20ms */
+ msleep(20);
+
+ /* Disable write protect */
+ r = regmap_write(data->regmap,
+ PAT9125_WRITE_PROTEC_REG,
+ PAT9125_DISABLE_WRITE_PROTECT_VAL);
+ if (r < 0)
+ goto reg_access_fail;
+
+ /* Set X-axis resolution (depends on application) */
+ r = regmap_write(data->regmap,
+ PAT9125_RES_X_REG,
+ 0x0A);
+ if (r < 0)
+ goto reg_access_fail;
+
+ /* Set Y-axis resolution (depends on application) */
+ r = regmap_write(data->regmap,
+ PAT9125_RES_Y_REG,
+ 0x0A);
+ if (r < 0)
+ goto reg_access_fail;
+
+ /* Enable write protection */
+ r = regmap_write(data->regmap,
+ PAT9125_WRITE_PROTEC_REG,
+ PAT9125_ENABLE_WRITE_PROTECT_VAL);
+ if (r < 0)
+ goto reg_access_fail;
+
+ r = devm_iio_device_register(&client->dev, indio_dev);
+ if (r) {
+ dev_err(&client->dev, "IIO device register failed");
+ return r;
+ }
+
+ i2c_set_clientdata(client, indio_dev);
+
+ dev_info(&client->dev, "%s: sensor '%s'\n",
+ dev_name(&indio_dev->dev),
+ client->name);
+
+ /* Make read to reset motion bit status */
+ r = pat9125_read_delta(data);
+ if (r)
+ goto reg_access_fail;
+
+ /* Init GPIO IRQ */
+ if (client->irq) {
+ r = devm_request_threaded_irq(&client->dev,
+ client->irq,
+ NULL,
+ pat9125_event_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "pat9125",
+ indio_dev);
+ if (r)
+ return r;
+ }
+ return 0;
+
+reg_access_fail:
+ dev_err(&client->dev, "register access failed %d", r);
+ return r;
+}
+
+static int pat9125_remove(struct i2c_client *client)
+{
+ dev_info(&client->dev, "PAT9125 removed\n");
+
+ return 0;
+}
+
+static const struct i2c_device_id pat9125_id[] = {
+ { "pat9125", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, pat9125_id);
+
+static const unsigned short normal_i2c[] = {
+ PAT9125_I2C_ADDR_HI,
+ PAT9125_I2C_ADDR_LO,
+ PAT9125_I2C_ADDR_NC,
+ I2C_CLIENT_END
+};
+
+static struct i2c_driver pat9125_driver = {
+ .driver = {
+ .name = "pat9125",
+ },
+ .probe = pat9125_probe,
+ .remove = pat9125_remove,
+ .address_list = normal_i2c,
+ .id_table = pat9125_id,
+};
+
+module_i2c_driver(pat9125_driver);
+
+MODULE_AUTHOR("Alexandre Mergnat <amergnat@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Optical Tracking sensor");
+MODULE_LICENSE("GPL");
+
--
2.7.4