Merge tag 'iio-for-5.8b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of new device support, cleanups and features for IIO in the 5.8 cycle

Usual mixed back but with a few subsystem wide or device type
wide cleanups.

New device support

* adis16475
  - New driver supporting adis16470, adis16475, adis16477, adis16465,
    adis16467, adis16500, adis16505 and adis16507.
    Includes some rework of the adis library to simplify using it
    for this new driver.
* ak8974
  - Add support for Alps hscdt008a. ID only. Related patches add support
    for scale.
* atlas-sensor
  - Add support for RTD-SM OEM temperature sensor.
* cm32181
  - Add support for CM3218 including support for SMBUS alert via
    ACPI resources.
* ltc2632
  - Add support for ltc2634-12/10/8 DACS including handling per
    device type numbers of channels.

Major Features

* cm32181
  - ACPI bindings including parsing CPM0 and CPM1 custom ACPI tables.
    Includes minor tidy ups and fixes.
* vcnl4000
  - Add event support
  - Add buffered data capture support
  - Add control of sampling frequency

Cleanups and minor fixes.

* core
  - Trivial rework of iio_device_alloc to use an early return and
    improve readability.
  - Precursors to addition of multiple buffer support. So far
    minor refactoring.
* subsystem wide
  - Use get_unaligned_be24 slightly improve readability over open
    coding it.
* adis drivers
  - Use iio_get_debugfs_dentry access function.
* bh1780, cm32181, cm3232, gp2ap02a00f, opt3001, st_uvis25, vl6180,
  dmard06, kxsd9
  - Drop use of of_match_ptr to allow ACPI based probing via PRP0001.
    Part of clear out of this to avoid cut and paste into new drivers.
* ad5592r, ad5593r
  - Fix typos
* ad5933
  - Use managed interfaces to automate error handling and remove.
* ak8974
  - Fix wrong number of 'real bits' for buffered data.
  - Refactor to pull measurement code out as separate function.
    bmp280
  - Fix lack of clamp on range during data capture.
* at91-sama5d2_adc
  - Handle unfinished conversions correctly.
  - Allow use of triggers other than it's own.
  - Reorganize buffer setup and tear down as part of long running
    subsystem wide rework.
* ccs811
  - Add DT binding docs and match table.
  - Support external reset and wakeup pins.
* hid-sensors
  - Reorganize buffer setup and tear down as part of long running
    subsystem wide rework.
* ltr501
  - Constify some structs.
* vcnl4000
  - Fix an endian issue by using explicit byte swapped i2c accessors.

* tag 'iio-for-5.8b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (74 commits)
  iio: light: ltr501: Constify structs
  staging: iio: ad5933: attach life-cycle of kfifo buffer to parent device and use managed calls throughout
  iio: bmp280: fix compensation of humidity
  iio: light: cm32181: Fix integartion time typo
  iio: light: cm32181: Add support for parsing CPM0 and CPM1 ACPI tables
  iio: light: cm32181: Make lux_per_bit and lux_per_bit_base_it runtime settings
  iio: light: cm32181: Use units of 1/100000th for calibscale and lux_per_bit
  iio: light: cm32181: Change reg_init to use a bitmap of which registers to init
  iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources
  iio: light: cm32181: Clean up the probe function a bit
  iio: light: cm32181: Add support for the CM3218
  iio: light: cm32181: Add some extra register defines
  iio: light: cm32181: Add support for ACPI enumeration
  iio: light: cm32181: Switch to new style i2c-driver probe function
  iio: hid-sensors: move triggered buffer setup into hid_sensor_setup_trigger
  iio: vcnl4000: Add buffer support for VCNL4010/20.
  iio: vcnl4000: Add sampling frequency support for VCNL4010/20.
  iio: vcnl4000: Add event support for VCNL4010/20.
  iio: vcnl4000: Factorize data reading and writing.
  iio: vcnl4000: Fix i2c swapped word reading.
  ...

1 files changed, 101 insertions, 11 deletions

diff --git a/drivers/iio/chemical/ccs811.c b/drivers/iio/chemical/ccs811.c
index 2ebdfc35bcda..3ecd633f9ed3 100644
--- a/drivers/iio/chemical/ccs811.c
+++ b/drivers/iio/chemical/ccs811.c
@@ -16,6 +16,7 @@
  */
 
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
@@ -36,6 +37,7 @@
 #define CCS811_ERR		0xE0
 /* Used to transition from boot to application mode */
 #define CCS811_APP_START	0xF4
+#define CCS811_SW_RESET		0xFF
 
 /* Status register flags */
 #define CCS811_STATUS_ERROR		BIT(0)
@@ -74,6 +76,7 @@ struct ccs811_data {
 	struct mutex lock; /* Protect readings */
 	struct ccs811_reading buffer;
 	struct iio_trigger *drdy_trig;
+	struct gpio_desc *wakeup_gpio;
 	bool drdy_trig_on;
 };
 
@@ -166,10 +169,25 @@ static int ccs811_setup(struct i2c_client *client)
 					 CCS811_MODE_IAQ_1SEC);
 }
 
+static void ccs811_set_wakeup(struct ccs811_data *data, bool enable)
+{
+	if (!data->wakeup_gpio)
+		return;
+
+	gpiod_set_value(data->wakeup_gpio, enable);
+
+	if (enable)
+		usleep_range(50, 60);
+	else
+		usleep_range(20, 30);
+}
+
 static int ccs811_get_measurement(struct ccs811_data *data)
 {
 	int ret, tries = 11;
 
+	ccs811_set_wakeup(data, true);
+
 	/* Maximum waiting time: 1s, as measurements are made every second */
 	while (tries-- > 0) {
 		ret = i2c_smbus_read_byte_data(data->client, CCS811_STATUS);
@@ -183,9 +201,12 @@ static int ccs811_get_measurement(struct ccs811_data *data)
 	if (!(ret & CCS811_STATUS_DATA_READY))
 		return -EIO;
 
-	return i2c_smbus_read_i2c_block_data(data->client,
+	ret = i2c_smbus_read_i2c_block_data(data->client,
 					    CCS811_ALG_RESULT_DATA, 8,
 					    (char *)&data->buffer);
+	ccs811_set_wakeup(data, false);
+
+	return ret;
 }
 
 static int ccs811_read_raw(struct iio_dev *indio_dev,
@@ -336,6 +357,45 @@ static irqreturn_t ccs811_data_rdy_trigger_poll(int irq, void *private)
 	return IRQ_HANDLED;
 }
 
+static int ccs811_reset(struct i2c_client *client)
+{
+	struct gpio_desc *reset_gpio;
+	int ret;
+
+	reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+					     GPIOD_OUT_LOW);
+	if (IS_ERR(reset_gpio))
+		return PTR_ERR(reset_gpio);
+
+	/* Try to reset using nRESET pin if available else do SW reset */
+	if (reset_gpio) {
+		gpiod_set_value(reset_gpio, 1);
+		usleep_range(20, 30);
+		gpiod_set_value(reset_gpio, 0);
+	} else {
+		/*
+		 * As per the datasheet, this sequence of values needs to be
+		 * written to the SW_RESET register for triggering the soft
+		 * reset in the device and placing it in boot mode.
+		 */
+		static const u8 reset_seq[] = {
+			0x11, 0xE5, 0x72, 0x8A,
+		};
+
+		ret = i2c_smbus_write_i2c_block_data(client, CCS811_SW_RESET,
+					     sizeof(reset_seq), reset_seq);
+		if (ret < 0) {
+			dev_err(&client->dev, "Failed to reset sensor\n");
+			return ret;
+		}
+	}
+
+	/* tSTART delay required after reset */
+	usleep_range(1000, 2000);
+
+	return 0;
+}
+
 static int ccs811_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
@@ -348,36 +408,59 @@ static int ccs811_probe(struct i2c_client *client,
 				     | I2C_FUNC_SMBUS_READ_I2C_BLOCK))
 		return -EOPNOTSUPP;
 
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	data->wakeup_gpio = devm_gpiod_get_optional(&client->dev, "wakeup",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(data->wakeup_gpio))
+		return PTR_ERR(data->wakeup_gpio);
+
+	ccs811_set_wakeup(data, true);
+
+	ret = ccs811_reset(client);
+	if (ret) {
+		ccs811_set_wakeup(data, false);
+		return ret;
+	}
+
 	/* Check hardware id (should be 0x81 for this family of devices) */
 	ret = i2c_smbus_read_byte_data(client, CCS811_HW_ID);
-	if (ret < 0)
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
 		return ret;
+	}
 
 	if (ret != CCS811_HW_ID_VALUE) {
 		dev_err(&client->dev, "hardware id doesn't match CCS81x\n");
+		ccs811_set_wakeup(data, false);
 		return -ENODEV;
 	}
 
 	ret = i2c_smbus_read_byte_data(client, CCS811_HW_VERSION);
-	if (ret < 0)
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
 		return ret;
+	}
 
 	if ((ret & CCS811_HW_VERSION_MASK) != CCS811_HW_VERSION_VALUE) {
 		dev_err(&client->dev, "no CCS811 sensor\n");
+		ccs811_set_wakeup(data, false);
 		return -ENODEV;
 	}
 
-	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
-	if (!indio_dev)
-		return -ENOMEM;
-
 	ret = ccs811_setup(client);
-	if (ret < 0)
+	if (ret < 0) {
+		ccs811_set_wakeup(data, false);
 		return ret;
+	}
 
-	data = iio_priv(indio_dev);
-	i2c_set_clientdata(client, indio_dev);
-	data->client = client;
+	ccs811_set_wakeup(data, false);
 
 	mutex_init(&data->lock);
 
@@ -466,9 +549,16 @@ static const struct i2c_device_id ccs811_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ccs811_id);
 
+static const struct of_device_id ccs811_dt_ids[] = {
+	{ .compatible = "ams,ccs811" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ccs811_dt_ids);
+
 static struct i2c_driver ccs811_driver = {
 	.driver = {
 		.name = "ccs811",
+		.of_match_table = ccs811_dt_ids,
 	},
 	.probe = ccs811_probe,
 	.remove = ccs811_remove,