build/patch/kernel/archive/sunxi-6.5/patches.megous/iio-magnetometer-add-a-driver-for-Voltafield-AF8133J-magnetomet.patch

From 94558c2254c47cb782421ab7f27c37ca3899f8f5 Mon Sep 17 00:00:00 2001
From: Icenowy Zheng <icenowy@aosc.io>
Date: Thu, 18 Mar 2021 20:19:25 +0800
Subject: [PATCH 392/464] iio: magnetometer: add a driver for Voltafield
 AF8133J magnetometer

AF8133J is a simple I2C-connected magnetometer, without interrupts.

Add a simple IIO driver for it.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Dalton Durst <dalton@ubports.com>
Signed-off-by: Shoji Keita <awaittrot@shjk.jp>
---
 drivers/iio/magnetometer/Kconfig   |  12 +
 drivers/iio/magnetometer/Makefile  |   1 +
 drivers/iio/magnetometer/af8133j.c | 351 +++++++++++++++++++++++++++++
 3 files changed, 364 insertions(+)
 create mode 100644 drivers/iio/magnetometer/af8133j.c

diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index 38532d840f2a..cd2917d71904 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -6,6 +6,18 @@
 
 menu "Magnetometer sensors"
 
+config AF8133J
+	tristate "Voltafield AF8133J 3-Axis Magnetometer"
+	depends on I2C
+	depends on OF
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for Voltafield AF8133J I2C-based
+	  3-axis magnetometer chip.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called af8133j.
+
 config AK8974
 	tristate "Asahi Kasei AK8974 3-Axis Magnetometer"
 	depends on I2C
diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
index b1c784ea71c8..ec5c46fbf999 100644
--- a/drivers/iio/magnetometer/Makefile
+++ b/drivers/iio/magnetometer/Makefile
@@ -4,6 +4,7 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AF8133J)	+= af8133j.o
 obj-$(CONFIG_AK8974)	+= ak8974.o
 obj-$(CONFIG_AK8975)	+= ak8975.o
 obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
diff --git a/drivers/iio/magnetometer/af8133j.c b/drivers/iio/magnetometer/af8133j.c
new file mode 100644
index 000000000000..f71b413ca3c9
--- /dev/null
+++ b/drivers/iio/magnetometer/af8133j.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * af8133j.c - Voltafield AF8133J magnetometer driver
+ *
+ * Based on mmc35240.c, which is:
+ *   Copyright (c) 2015, Intel Corporation.
+ *
+ * TODO: 
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define AF8133J_DRV_NAME "af8133j"
+#define AF8133J_REGMAP_NAME "af8133j_regmap"
+
+#define AF8133J_REG_OUT		0x03
+/* Little endian */
+#define AF8133J_REG_OUT_SIZE	0x06
+
+#define AF8133J_REG_PCODE	0x00
+#define AF8133J_REG_PCODE_VAL	0x5e
+
+/* Named STATUS in datasheet, renamed here to prevent confusion with STATE */
+#define AF8133J_REG_DRDY	0x02
+#define AF8133J_REG_DRDY_ACQ	BIT(0)
+/* Named STATE in datasheet, renamed here to prevent confusion */
+#define AF8133J_REG_STATE	0x0a
+#define AF8133J_REG_STATE_STBY	0x00
+#define AF8133J_REG_STATE_WORK	0x01
+#define AF8133J_REG_RANGE	0x0b
+#define AF8133J_REG_RANGE_22G	0x12
+#define AF8133J_REG_RANGE_12G	0x34
+/* Software reset */
+#define AF8133J_REG_SWR		0x11
+#define AF8133J_REG_SWR_PERFORM	BIT(0)
+
+struct af8133j_data {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct mutex mutex;
+
+	struct gpio_desc *reset_gpiod;
+	struct regulator *avdd;
+	struct regulator *dvdd;
+	struct iio_mount_matrix orientation;
+};
+
+enum af8133j_axis {
+	AXIS_X = 0,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+static struct iio_mount_matrix *
+af8133j_get_mount_matrix(struct iio_dev *indio_dev,
+			 const struct iio_chan_spec *chan)
+{
+	struct af8133j_data *data = iio_priv(indio_dev);
+	return &data->orientation;
+}
+
+static const struct iio_chan_spec_ext_info af8133j_ext_info[] = {
+	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, af8133j_get_mount_matrix),
+	{ }
+};
+
+#define AF8133J_CHANNEL(_axis) { \
+	.type = IIO_MAGN, \
+	.modified = 1, \
+	.channel2 = IIO_MOD_ ## _axis, \
+	.address = AXIS_ ## _axis, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.ext_info = af8133j_ext_info, \
+}
+
+static const struct iio_chan_spec af8133j_channels[] = {
+	AF8133J_CHANNEL(X),
+	AF8133J_CHANNEL(Y),
+	AF8133J_CHANNEL(Z),
+};
+
+static int af8133j_init(struct af8133j_data *data)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(data->regmap, AF8133J_REG_PCODE, &val);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Error reading product code\n");
+		return ret;
+	}
+
+	if (val != AF8133J_REG_PCODE_VAL) {
+		dev_warn(&data->client->dev,
+			"Unknown AF8133J product code %x\n", val);
+	}
+
+	/* Reset the chip */
+	ret = regmap_write(data->regmap, AF8133J_REG_SWR,
+			   AF8133J_REG_SWR_PERFORM);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to write regmap\n");
+		return ret;
+	}
+
+	/* Wait for reset finish */
+	usleep_range(1000, 1100);
+
+	/* Check whether the reset bit is cleared */
+	ret = regmap_read(data->regmap, AF8133J_REG_SWR, &val);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to read regmap\n");
+		return ret;
+	}
+	if (val & AF8133J_REG_SWR_PERFORM) {
+		dev_err(&data->client->dev, "Device is not responding\n");
+		return -EIO;
+	}
+
+	/* The reset value should satisfy us now. */
+
+	return 0;
+}
+
+static int af8133j_take_measurement(struct af8133j_data *data)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_write(data->regmap, AF8133J_REG_STATE,
+			   AF8133J_REG_STATE_WORK);
+	if (ret < 0)
+		return ret;
+
+	/* The datasheet says "Mesaure Time <1.5ms" */
+	ret = regmap_read_poll_timeout(data->regmap, AF8133J_REG_DRDY, val,
+				       val & AF8133J_REG_DRDY_ACQ,
+				       100, 1500);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(data->regmap, AF8133J_REG_STATE,
+			   AF8133J_REG_STATE_STBY);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int af8133j_read_measurement(struct af8133j_data *data, __le16 buf[3])
+{
+	int ret;
+
+	ret = af8133j_take_measurement(data);
+	if (ret < 0)
+		return ret;
+
+	return regmap_bulk_read(data->regmap, AF8133J_REG_OUT, buf,
+				3 * sizeof(__le16));
+}
+
+static int af8133j_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int *val,
+			     int *val2, long mask)
+{
+	struct af8133j_data *data = iio_priv(indio_dev);
+	int ret;
+	__le16 buf[3];
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->mutex);
+		ret = af8133j_read_measurement(data, buf);
+		mutex_unlock(&data->mutex);
+		if (ret < 0)
+			return ret;
+		*val = sign_extend32(le16_to_cpu(buf[chan->address]), 15);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/* We only use the default 12G scale now */
+		*val = 0;
+		*val2 = 12 * 1000000 / 32768;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info af8133j_info = {
+	.read_raw	= af8133j_read_raw,
+};
+
+static const struct regmap_config af8133j_regmap_config = {
+	.name = AF8133J_REGMAP_NAME,
+
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = AF8133J_REG_SWR,
+	.cache_type = REGCACHE_NONE,
+};
+
+static int af8133j_probe(struct i2c_client *client)
+{
+	struct af8133j_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	regmap = devm_regmap_init_i2c(client, &af8133j_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "regmap initialization failed\n");
+		return PTR_ERR(regmap);
+	}
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->regmap = regmap;
+
+	data->reset_gpiod = devm_gpiod_get(&client->dev, "reset",
+					   GPIOD_OUT_HIGH);
+	if (IS_ERR(data->reset_gpiod)) {
+		dev_err(&client->dev, "Got error while retrieving reset gpio\n");
+		ret = PTR_ERR(data->reset_gpiod);
+		goto out_release_reset_gpio;
+	}
+
+	data->avdd = devm_regulator_get(&client->dev, "avdd");
+	if (IS_ERR(data->avdd)) {
+		dev_err(&client->dev, "Got error while retrieving avdd reg\n");
+		ret = PTR_ERR(data->avdd);
+		goto out_release_reset_gpio;
+	}
+
+	data->dvdd = devm_regulator_get(&client->dev, "dvdd");
+	if (IS_ERR(data->dvdd)) {
+		dev_err(&client->dev, "Got error while retrieving dvdd reg\n");
+		ret = PTR_ERR(data->dvdd);
+		goto out_release_reset_gpio;
+	}
+
+	mutex_init(&data->mutex);
+
+	ret = iio_read_mount_matrix(&client->dev, "mount-matrix",
+			&data->orientation);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &af8133j_info;
+	indio_dev->name = AF8133J_DRV_NAME;
+	indio_dev->channels = af8133j_channels;
+	indio_dev->num_channels = ARRAY_SIZE(af8133j_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	/* Power sequence */
+	ret = regulator_enable(data->avdd);
+	if (ret) {
+		dev_err(&client->dev, "Failed to enable avdd regulator");
+		goto out_release_reset_gpio;
+	}
+
+	ret = regulator_enable(data->dvdd);
+	if (ret) {
+		dev_err(&client->dev, "Failed to enable dvdd regulator");
+		goto out_disable_avdd;
+	}
+
+	msleep(15);
+
+	gpiod_set_value_cansleep(data->reset_gpiod, 0);
+
+	msleep(1);
+
+	ret = af8133j_init(data);
+	if (ret) {
+		dev_err(&client->dev, "Failed to init af8133j");
+		goto out_assert_reset;
+	}
+
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret) {
+		dev_err(&client->dev, "Failed to register iio device");
+		goto out_assert_reset;
+	}
+
+	return 0;
+
+out_assert_reset:
+	gpiod_set_value_cansleep(data->reset_gpiod, 1);
+	regulator_disable(data->dvdd);
+out_disable_avdd:
+	regulator_disable(data->avdd);
+out_release_reset_gpio:
+	gpiod_direction_input(data->reset_gpiod);
+
+	return ret;
+}
+
+static int af8133j_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct af8133j_data *data = iio_priv(indio_dev);
+
+	gpiod_set_value_cansleep(data->reset_gpiod, 0);
+	regulator_disable(data->dvdd);
+	regulator_disable(data->avdd);
+
+	return 0;
+}
+
+static const struct of_device_id af8133j_of_match[] = {
+	{ .compatible = "voltafield,af8133j", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, af8133j_of_match);
+
+static const struct i2c_device_id af8133j_id[] = {
+	{"af8133j", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, af8133j_id);
+
+static struct i2c_driver af8133j_driver = {
+	.driver = {
+		.name = AF8133J_DRV_NAME,
+		.of_match_table = af8133j_of_match,
+	},
+	.probe		= af8133j_probe,
+	.remove		= af8133j_remove,
+	.id_table	= af8133j_id,
+};
+
+module_i2c_driver(af8133j_driver);
+
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_DESCRIPTION("Voltafield AF8133J magnetic sensor driver");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1