[PATCH v6 0/4] iio: accel: adxl345: Split driver into core and I2C then add SPI support

[PATCH v6 0/4] iio: accel: adxl345: Split driver into core and I2C then add SPI support

[Eva Rachel Retuya]

This patchset modifies the adxl345 to use regmap. In doing so, we can
easily introduce SPI support and let regmap handle the rest.

Recap of basic features: read_raw for x, y and z axes, scale. After
applying this series, driver now supports the SPI protocol and enumeration
of device via device tree.

Changes from v5:
[PATCH 1/4]
* Add Rob's Acked-by tag
[PATCH 2/4]
* Re-order local variable declarations from longest to shortest line
* Remove explicit casting to int in handling devm_regmap_init_i2c() error,
  use %ld instead
[PATCH 3/4]
* Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
* Rename functions from *_common_* to *_core_*
* Modify header comment: place indication at the beginning
* Remove explicit casting to int in handling devm_regmap_init_i2c() error,
  use %ld instead
* Remove temporary variable 'name'
[PATCH 4/4]
* Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
* Modify header comment: place indication at the beginning
* Re-order local variable declarations from longest to shortest line
* Remove explicit casting to int in handling devm_regmap_init_spi() error,
  use %ld instead
* Rename functions calls from *_common_* to *_core_*

Changes from v4:
* Update subject-prefix of [PATCH 1/4]
* Update node name from "adxl345@unit-address" to "accelerometer@unit-address"
* Add Andy's Reviewed-by tag

Changes from v3:
[PATCH 1/4]
* None
[PATCH 2/4]
* Keep intact I2C client structure which was deleted from v3
* Make use of regmap_get_device to retrieve struct device, use these for
  debugging prints instead of &client->dev.
[PATCH 3/4] and [PATCH 4/4]
* Revert to explicit and separate I2C and SPI configuration
* Add OF match table, make it enumerable in ACPI environment (Andy's suggestion)

Changes from v2:
* Drop PATCH 4 iio: accel: adxl345: Add ACPI support
* Add OF match table on both I2C and SPI files and document them

Changes from v1:
[PATCH 1/4]
* Move other deletions from patch 2 in here -- make it clear what got deleted
  and/or modified that is hard to see previously
* Introduce the driver header file "adxl345.h" here instead of doing it in the
  next patch
* Completely omit traces of i2c_client and let this file (adxl345.c) mirror the
  core file on the next patch.
* Improve debugging print about invalid device ID in probe.
[PATCH 2/4]
* Update Kconfig to Jonathan's preferred style
* Improve similarity index from 78% to 100% (rename detection)
[PATCH 4/4]
* Correct acpi_device_id: ADX0345 -> ADS0345

Eva Rachel Retuya (4):
  dt-bindings: iio: accel: Document ADXL345 accelerometer binding
  iio: accel: adxl345: Use I2C regmap instead of direct I2C access
  iio: accel: adxl345: Split driver into core and I2C
  iio: accel: adxl345: Add SPI support

 .../devicetree/bindings/iio/accel/adxl345.txt      | 38 +++++++++
 drivers/iio/accel/Kconfig                          | 28 ++++++-
 drivers/iio/accel/Makefile                         |  4 +-
 drivers/iio/accel/adxl345.h                        | 18 +++++
 drivers/iio/accel/{adxl345.c => adxl345_core.c}    | 91 +++++++++-------------
 drivers/iio/accel/adxl345_i2c.c                    | 73 +++++++++++++++++
 drivers/iio/accel/adxl345_spi.c                    | 81 +++++++++++++++++++
 7 files changed, 275 insertions(+), 58 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/iio/accel/adxl345.txt
 create mode 100644 drivers/iio/accel/adxl345.h
 rename drivers/iio/accel/{adxl345.c => adxl345_core.c} (61%)
 create mode 100644 drivers/iio/accel/adxl345_i2c.c
 create mode 100644 drivers/iio/accel/adxl345_spi.c

-- 
2.7.4

[PATCH v6 1/4] dt-bindings: iio: accel: Document ADXL345 accelerometer binding

[Eva Rachel Retuya]

Add the device tree binding documentation for the ADXL345 3-axis digital
accelerometer.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---
Change from v5:
* Add Rob's Acked-by tag

 .../devicetree/bindings/iio/accel/adxl345.txt      | 38 ++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/accel/adxl345.txt

diff --git a/Documentation/devicetree/bindings/iio/accel/adxl345.txt b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
new file mode 100644
index 0000000..e7111b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
@@ -0,0 +1,38 @@
+Analog Devices ADXL345 3-Axis, +/-(2g/4g/8g/16g) Digital Accelerometer
+
+http://www.analog.com/en/products/mems/accelerometers/adxl345.html
+
+Required properties:
+ - compatible : should be "adi,adxl345"
+ - reg : the I2C address or SPI chip select number of the sensor
+
+Required properties for SPI bus usage:
+ - spi-max-frequency : set maximum clock frequency, must be 5000000
+ - spi-cpol and spi-cpha : must be defined for adxl345 to enable SPI mode 3
+
+Optional properties:
+ - interrupt-parent : phandle to the parent interrupt controller as documented
+   in Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+ - interrupts: interrupt mapping for IRQ as documented in
+   Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+
+Example for a I2C device node:
+
+	accelerometer@2a {
+		compatible = "adi,adxl345";
+		reg = <0x53>;
+		interrupt-parent = <&gpio1>;
+		interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
+Example for a SPI device node:
+
+	accelerometer@0 {
+		compatible = "adi,adxl345";
+		reg = <0>;
+		spi-max-frequency = <5000000>;
+		spi-cpol;
+		spi-cpha;
+		interrupt-parent = <&gpio1>;
+		interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
+	};
-- 
2.7.4

[PATCH v6 2/4] iio: accel: adxl345: Use I2C regmap instead of direct I2C access

[Eva Rachel Retuya]

Convert the driver to use regmap instead of I2C-specific functions. This
is done in preparation for splitting this driver into core and
I2C-specific code as well as introduction of SPI driver.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
Changes from v5:
* Re-order local variable declarations from longest to shortest line
* Remove explicit casting to int in handling devm_regmap_init_i2c() error,
  use %ld instead

 drivers/iio/accel/Kconfig   |  1 +
 drivers/iio/accel/adxl345.c | 66 +++++++++++++++++++++++++++++----------------
 2 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 2308bac..26b8614 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -9,6 +9,7 @@ config ADXL345
 	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
 	depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
 	depends on I2C
+	select REGMAP_I2C
 	help
 	  Say Y here if you want to build support for the Analog Devices
 	  ADXL345 3-axis digital accelerometer.
diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345.c
index c34991f..87fdd9f 100644
--- a/drivers/iio/accel/adxl345.c
+++ b/drivers/iio/accel/adxl345.c
@@ -14,6 +14,7 @@
 
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
 
@@ -45,10 +46,15 @@
 static const int adxl345_uscale = 38300;
 
 struct adxl345_data {
-	struct i2c_client *client;
+	struct regmap *regmap;
 	u8 data_range;
 };
 
+static const struct regmap_config adxl345_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
 #define ADXL345_CHANNEL(reg, axis) {					\
 	.type = IIO_ACCEL,						\
 	.modified = 1,							\
@@ -69,6 +75,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 			    int *val, int *val2, long mask)
 {
 	struct adxl345_data *data = iio_priv(indio_dev);
+	__le16 regval;
 	int ret;
 
 	switch (mask) {
@@ -78,11 +85,12 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
 		 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
 		 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
 		 */
-		ret = i2c_smbus_read_word_data(data->client, chan->address);
+		ret = regmap_bulk_read(data->regmap, chan->address, &regval,
+				       sizeof(regval));
 		if (ret < 0)
 			return ret;
 
-		*val = sign_extend32(ret, 12);
+		*val = sign_extend32(le16_to_cpu(regval), 12);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
@@ -104,37 +112,50 @@ static int adxl345_probe(struct i2c_client *client,
 {
 	struct adxl345_data *data;
 	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	struct device *dev;
+	u32 regval;
 	int ret;
 
-	ret = i2c_smbus_read_byte_data(client, ADXL345_REG_DEVID);
+	regmap = devm_regmap_init_i2c(client, &adxl345_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Error initializing regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	dev = regmap_get_device(regmap);
+
+	ret = regmap_read(regmap, ADXL345_REG_DEVID, &regval);
 	if (ret < 0) {
-		dev_err(&client->dev, "Error reading device ID: %d\n", ret);
+		dev_err(dev, "Error reading device ID: %d\n", ret);
 		return ret;
 	}
 
-	if (ret != ADXL345_DEVID) {
-		dev_err(&client->dev, "Invalid device ID: %d\n", ret);
+	if (regval != ADXL345_DEVID) {
+		dev_err(dev, "Invalid device ID: %x, expected %x\n",
+			regval, ADXL345_DEVID);
 		return -ENODEV;
 	}
 
-	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;
 
 	data = iio_priv(indio_dev);
-	i2c_set_clientdata(client, indio_dev);
-	data->client = client;
+	dev_set_drvdata(dev, indio_dev);
+	data->regmap = regmap;
 	/* Enable full-resolution mode */
 	data->data_range = ADXL345_DATA_FORMAT_FULL_RES;
 
-	ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_DATA_FORMAT,
-					data->data_range);
+	ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
+			   data->data_range);
 	if (ret < 0) {
-		dev_err(&client->dev, "Failed to set data range: %d\n", ret);
+		dev_err(dev, "Failed to set data range: %d\n", ret);
 		return ret;
 	}
 
-	indio_dev->dev.parent = &client->dev;
+	indio_dev->dev.parent = dev;
 	indio_dev->name = id->name;
 	indio_dev->info = &adxl345_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
@@ -142,19 +163,18 @@ static int adxl345_probe(struct i2c_client *client,
 	indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
 
 	/* Enable measurement mode */
-	ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-					ADXL345_POWER_CTL_MEASURE);
+	ret = regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+			   ADXL345_POWER_CTL_MEASURE);
 	if (ret < 0) {
-		dev_err(&client->dev, "Failed to enable measurement mode: %d\n",
-			ret);
+		dev_err(dev, "Failed to enable measurement mode: %d\n", ret);
 		return ret;
 	}
 
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
-		dev_err(&client->dev, "iio_device_register failed: %d\n", ret);
-		i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-					  ADXL345_POWER_CTL_STANDBY);
+		dev_err(dev, "iio_device_register failed: %d\n", ret);
+		regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+			     ADXL345_POWER_CTL_STANDBY);
 	}
 
 	return ret;
@@ -167,8 +187,8 @@ static int adxl345_remove(struct i2c_client *client)
 
 	iio_device_unregister(indio_dev);
 
-	return i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
-					 ADXL345_POWER_CTL_STANDBY);
+	return regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
+			    ADXL345_POWER_CTL_STANDBY);
 }
 
 static const struct i2c_device_id adxl345_i2c_id[] = {
-- 
2.7.4

[PATCH v6 3/4] iio: accel: adxl345: Split driver into core and I2C

[Eva Rachel Retuya]

Move I2C-specific code into its own file and rely on regmap to access
registers. The core code provides access to x, y, z and scale readings.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
Changes from v5:
* Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
* Rename functions from *_common_* to *_core_*
* Modify header comment: place indication at the beginning
* Remove explicit casting to int in handling devm_regmap_init_i2c() error,
  use %ld instead
* Remove temporary variable 'name'

 drivers/iio/accel/Kconfig                       | 13 +++--
 drivers/iio/accel/Makefile                      |  3 +-
 drivers/iio/accel/adxl345.h                     | 18 ++++++
 drivers/iio/accel/{adxl345.c => adxl345_core.c} | 57 ++++---------------
 drivers/iio/accel/adxl345_i2c.c                 | 73 +++++++++++++++++++++++++
 5 files changed, 113 insertions(+), 51 deletions(-)
 create mode 100644 drivers/iio/accel/adxl345.h
 rename drivers/iio/accel/{adxl345.c => adxl345_core.c} (77%)
 create mode 100644 drivers/iio/accel/adxl345_i2c.c

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 26b8614..a725227 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -6,16 +6,21 @@
 menu "Accelerometers"
 
 config ADXL345
-	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
-	depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
+	tristate
+
+config ADXL345_I2C
+	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer I2C Driver"
+	depends on INPUT_ADXL34X=n
 	depends on I2C
+	select ADXL345
 	select REGMAP_I2C
 	help
 	  Say Y here if you want to build support for the Analog Devices
 	  ADXL345 3-axis digital accelerometer.
 
-	  To compile this driver as a module, choose M here: the
-	  module will be called adxl345.
+	  To compile this driver as a module, choose M here: the module
+	  will be called adxl345_i2c and you will also get adxl345_core
+	  for the core module.
 
 config BMA180
 	tristate "Bosch BMA180/BMA250 3-Axis Accelerometer Driver"
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 618488d..3f4a6d6 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -3,7 +3,8 @@
 #
 
 # When adding new entries keep the list in alphabetical order
-obj-$(CONFIG_ADXL345) += adxl345.o
+obj-$(CONFIG_ADXL345) += adxl345_core.o
+obj-$(CONFIG_ADXL345_I2C) += adxl345_i2c.o
 obj-$(CONFIG_BMA180) += bma180.o
 obj-$(CONFIG_BMA220) += bma220_spi.o
 obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
new file mode 100644
index 0000000..c1ddf39
--- /dev/null
+++ b/drivers/iio/accel/adxl345.h
@@ -0,0 +1,18 @@
+/*
+ * ADXL345 3-Axis Digital Accelerometer
+ *
+ * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ */
+
+#ifndef _ADXL345_H_
+#define _ADXL345_H_
+
+int adxl345_core_probe(struct device *dev, struct regmap *regmap,
+		       const char *name);
+int adxl345_core_remove(struct device *dev);
+
+#endif /* _ADXL345_H_ */
diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345_core.c
similarity index 77%
rename from drivers/iio/accel/adxl345.c
rename to drivers/iio/accel/adxl345_core.c
index 87fdd9f..9ccb582 100644
--- a/drivers/iio/accel/adxl345.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -1,23 +1,20 @@
 /*
- * ADXL345 3-Axis Digital Accelerometer
+ * ADXL345 3-Axis Digital Accelerometer IIO core driver
  *
  * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
  *
  * This file is subject to the terms and conditions of version 2 of
  * the GNU General Public License. See the file COPYING in the main
  * directory of this archive for more details.
- *
- * IIO driver for ADXL345
- * 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or
- * 0x53 (ALT ADDRESS pin grounded)
  */
 
-#include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
 
+#include "adxl345.h"
+
 #define ADXL345_REG_DEVID		0x00
 #define ADXL345_REG_POWER_CTL		0x2D
 #define ADXL345_REG_DATA_FORMAT		0x31
@@ -50,11 +47,6 @@ struct adxl345_data {
 	u8 data_range;
 };
 
-static const struct regmap_config adxl345_regmap_config = {
-	.reg_bits = 8,
-	.val_bits = 8,
-};
-
 #define ADXL345_CHANNEL(reg, axis) {					\
 	.type = IIO_ACCEL,						\
 	.modified = 1,							\
@@ -107,25 +99,14 @@ static const struct iio_info adxl345_info = {
 	.read_raw	= adxl345_read_raw,
 };
 
-static int adxl345_probe(struct i2c_client *client,
-			 const struct i2c_device_id *id)
+int adxl345_core_probe(struct device *dev, struct regmap *regmap,
+		       const char *name)
 {
 	struct adxl345_data *data;
 	struct iio_dev *indio_dev;
-	struct regmap *regmap;
-	struct device *dev;
 	u32 regval;
 	int ret;
 
-	regmap = devm_regmap_init_i2c(client, &adxl345_regmap_config);
-	if (IS_ERR(regmap)) {
-		dev_err(&client->dev, "Error initializing regmap: %ld\n",
-			PTR_ERR(regmap));
-		return PTR_ERR(regmap);
-	}
-
-	dev = regmap_get_device(regmap);
-
 	ret = regmap_read(regmap, ADXL345_REG_DEVID, &regval);
 	if (ret < 0) {
 		dev_err(dev, "Error reading device ID: %d\n", ret);
@@ -156,7 +137,7 @@ static int adxl345_probe(struct i2c_client *client,
 	}
 
 	indio_dev->dev.parent = dev;
-	indio_dev->name = id->name;
+	indio_dev->name = name;
 	indio_dev->info = &adxl345_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = adxl345_channels;
@@ -179,10 +160,11 @@ static int adxl345_probe(struct i2c_client *client,
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(adxl345_core_probe);
 
-static int adxl345_remove(struct i2c_client *client)
+int adxl345_core_remove(struct device *dev)
 {
-	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct adxl345_data *data = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
@@ -190,25 +172,8 @@ static int adxl345_remove(struct i2c_client *client)
 	return regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
 			    ADXL345_POWER_CTL_STANDBY);
 }
-
-static const struct i2c_device_id adxl345_i2c_id[] = {
-	{ "adxl345", 0 },
-	{ }
-};
-
-MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id);
-
-static struct i2c_driver adxl345_driver = {
-	.driver = {
-		.name	= "adxl345",
-	},
-	.probe		= adxl345_probe,
-	.remove		= adxl345_remove,
-	.id_table	= adxl345_i2c_id,
-};
-
-module_i2c_driver(adxl345_driver);
+EXPORT_SYMBOL_GPL(adxl345_core_remove);
 
 MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
-MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer driver");
+MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/accel/adxl345_i2c.c b/drivers/iio/accel/adxl345_i2c.c
new file mode 100644
index 0000000..05e1ec4
--- /dev/null
+++ b/drivers/iio/accel/adxl345_i2c.c
@@ -0,0 +1,73 @@
+/*
+ * ADXL345 3-Axis Digital Accelerometer I2C driver
+ *
+ * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or
+ * 0x53 (ALT ADDRESS pin grounded)
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "adxl345.h"
+
+static const struct regmap_config adxl345_i2c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int adxl345_i2c_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &adxl345_i2c_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Error initializing i2c regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return adxl345_core_probe(&client->dev, regmap, id ? id->name : NULL);
+}
+
+static int adxl345_i2c_remove(struct i2c_client *client)
+{
+	return adxl345_core_remove(&client->dev);
+}
+
+static const struct i2c_device_id adxl345_i2c_id[] = {
+	{ "adxl345", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id);
+
+static const struct of_device_id adxl345_of_match[] = {
+	{ .compatible = "adi,adxl345" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, adxl345_of_match);
+
+static struct i2c_driver adxl345_i2c_driver = {
+	.driver = {
+		.name	= "adxl345_i2c",
+		.of_match_table = adxl345_of_match,
+	},
+	.probe		= adxl345_i2c_probe,
+	.remove		= adxl345_i2c_remove,
+	.id_table	= adxl345_i2c_id,
+};
+
+module_i2c_driver(adxl345_i2c_driver);
+
+MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
+MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer I2C driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

[PATCH v6 4/4] iio: accel: adxl345: Add SPI support

[Eva Rachel Retuya]

Add SPI driver that initializes SPI regmap for the adxl345 core driver.
The driver supports the same functionality as I2C namely the x, y, z and
scale readings.

Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
Changes from v5:
* Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
* Modify header comment: place indication at the beginning
* Re-order local variable declarations from longest to shortest line
* Remove explicit casting to int in handling devm_regmap_init_spi() error,
  use %ld instead
* Rename functions calls from *_common_* to *_core_*

 drivers/iio/accel/Kconfig       | 14 +++++++
 drivers/iio/accel/Makefile      |  1 +
 drivers/iio/accel/adxl345_spi.c | 81 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+)
 create mode 100644 drivers/iio/accel/adxl345_spi.c

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index a725227..15de262 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -22,6 +22,20 @@ config ADXL345_I2C
 	  will be called adxl345_i2c and you will also get adxl345_core
 	  for the core module.
 
+config ADXL345_SPI
+	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer SPI Driver"
+	depends on INPUT_ADXL34X=n
+	depends on SPI
+	select ADXL345
+	select REGMAP_SPI
+	help
+	  Say Y here if you want to build support for the Analog Devices
+	  ADXL345 3-axis digital accelerometer.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called adxl345_spi and you will also get adxl345_core
+	  for the core module.
+
 config BMA180
 	tristate "Bosch BMA180/BMA250 3-Axis Accelerometer Driver"
 	depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 3f4a6d6..31fba19 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -5,6 +5,7 @@
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_ADXL345) += adxl345_core.o
 obj-$(CONFIG_ADXL345_I2C) += adxl345_i2c.o
+obj-$(CONFIG_ADXL345_SPI) += adxl345_spi.o
 obj-$(CONFIG_BMA180) += bma180.o
 obj-$(CONFIG_BMA220) += bma220_spi.o
 obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
diff --git a/drivers/iio/accel/adxl345_spi.c b/drivers/iio/accel/adxl345_spi.c
new file mode 100644
index 0000000..6d65819
--- /dev/null
+++ b/drivers/iio/accel/adxl345_spi.c
@@ -0,0 +1,81 @@
+/*
+ * ADXL345 3-Axis Digital Accelerometer SPI driver
+ *
+ * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "adxl345.h"
+
+#define ADXL345_MAX_SPI_FREQ_HZ		5000000
+
+static const struct regmap_config adxl345_spi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	 /* Setting bits 7 and 6 enables multiple-byte read */
+	.read_flag_mask = BIT(7) | BIT(6),
+};
+
+static int adxl345_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct regmap *regmap;
+
+	/* Bail out if max_speed_hz exceeds 5 MHz */
+	if (spi->max_speed_hz > ADXL345_MAX_SPI_FREQ_HZ) {
+		dev_err(&spi->dev, "SPI CLK, %d Hz exceeds 5 MHz\n",
+			spi->max_speed_hz);
+		return -EINVAL;
+	}
+
+	regmap = devm_regmap_init_spi(spi, &adxl345_spi_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
+			PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return adxl345_core_probe(&spi->dev, regmap, id->name);
+}
+
+static int adxl345_spi_remove(struct spi_device *spi)
+{
+	return adxl345_core_remove(&spi->dev);
+}
+
+static const struct spi_device_id adxl345_spi_id[] = {
+	{ "adxl345", 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(spi, adxl345_spi_id);
+
+static const struct of_device_id adxl345_of_match[] = {
+	{ .compatible = "adi,adxl345" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, adxl345_of_match);
+
+static struct spi_driver adxl345_spi_driver = {
+	.driver = {
+		.name	= "adxl345_spi",
+		.of_match_table = adxl345_of_match,
+	},
+	.probe		= adxl345_spi_probe,
+	.remove		= adxl345_spi_remove,
+	.id_table	= adxl345_spi_id,
+};
+
+module_spi_driver(adxl345_spi_driver);
+
+MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
+MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer SPI driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

Re: [PATCH v6 1/4] dt-bindings: iio: accel: Document ADXL345 accelerometer binding

[Jonathan Cameron]

On 04/03/17 08:31, Eva Rachel Retuya wrote:
> Add the device tree binding documentation for the ADXL345 3-axis digital
> accelerometer.
> 
> Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
> Acked-by: Rob Herring <robh@kernel.org>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with.

Thanks,

Jonathan
> ---
> Change from v5:
> * Add Rob's Acked-by tag
> 
>  .../devicetree/bindings/iio/accel/adxl345.txt      | 38 ++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/accel/adxl345.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/accel/adxl345.txt b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
> new file mode 100644
> index 0000000..e7111b0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/accel/adxl345.txt
> @@ -0,0 +1,38 @@
> +Analog Devices ADXL345 3-Axis, +/-(2g/4g/8g/16g) Digital Accelerometer
> +
> +http://www.analog.com/en/products/mems/accelerometers/adxl345.html
> +
> +Required properties:
> + - compatible : should be "adi,adxl345"
> + - reg : the I2C address or SPI chip select number of the sensor
> +
> +Required properties for SPI bus usage:
> + - spi-max-frequency : set maximum clock frequency, must be 5000000
> + - spi-cpol and spi-cpha : must be defined for adxl345 to enable SPI mode 3
> +
> +Optional properties:
> + - interrupt-parent : phandle to the parent interrupt controller as documented
> +   in Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> + - interrupts: interrupt mapping for IRQ as documented in
> +   Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> +
> +Example for a I2C device node:
> +
> +	accelerometer@2a {
> +		compatible = "adi,adxl345";
> +		reg = <0x53>;
> +		interrupt-parent = <&gpio1>;
> +		interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
> +	};
> +
> +Example for a SPI device node:
> +
> +	accelerometer@0 {
> +		compatible = "adi,adxl345";
> +		reg = <0>;
> +		spi-max-frequency = <5000000>;
> +		spi-cpol;
> +		spi-cpha;
> +		interrupt-parent = <&gpio1>;
> +		interrupts = <0 IRQ_TYPE_LEVEL_HIGH>;
> +	};
> 

Re: [PATCH v6 2/4] iio: accel: adxl345: Use I2C regmap instead of direct I2C access

[Jonathan Cameron]

On 04/03/17 08:31, Eva Rachel Retuya wrote:
> Convert the driver to use regmap instead of I2C-specific functions. This
> is done in preparation for splitting this driver into core and
> I2C-specific code as well as introduction of SPI driver.
> 
> Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Applied to the togreg branch of iio.git and pushed out as testing for the
autobuilders to play with it.

Thanks,

Jonathan
> ---
> Changes from v5:
> * Re-order local variable declarations from longest to shortest line
Whilst I've no objection to this, it's definitely more of a personal taste thing
than anything.  Probably wise to just agree though as quicker than arguing and Andy
did say they were minor points that he would have done differently rather than
important!


> * Remove explicit casting to int in handling devm_regmap_init_i2c() error,
>   use %ld instead
> 
>  drivers/iio/accel/Kconfig   |  1 +
>  drivers/iio/accel/adxl345.c | 66 +++++++++++++++++++++++++++++----------------
>  2 files changed, 44 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 2308bac..26b8614 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -9,6 +9,7 @@ config ADXL345
>  	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
>  	depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
>  	depends on I2C
> +	select REGMAP_I2C
>  	help
>  	  Say Y here if you want to build support for the Analog Devices
>  	  ADXL345 3-axis digital accelerometer.
> diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345.c
> index c34991f..87fdd9f 100644
> --- a/drivers/iio/accel/adxl345.c
> +++ b/drivers/iio/accel/adxl345.c
> @@ -14,6 +14,7 @@
>  
>  #include <linux/i2c.h>
>  #include <linux/module.h>
> +#include <linux/regmap.h>
>  
>  #include <linux/iio/iio.h>
>  
> @@ -45,10 +46,15 @@
>  static const int adxl345_uscale = 38300;
>  
>  struct adxl345_data {
> -	struct i2c_client *client;
> +	struct regmap *regmap;
>  	u8 data_range;
>  };
>  
> +static const struct regmap_config adxl345_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +};
> +
>  #define ADXL345_CHANNEL(reg, axis) {					\
>  	.type = IIO_ACCEL,						\
>  	.modified = 1,							\
> @@ -69,6 +75,7 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
>  			    int *val, int *val2, long mask)
>  {
>  	struct adxl345_data *data = iio_priv(indio_dev);
> +	__le16 regval;
>  	int ret;
>  
>  	switch (mask) {
> @@ -78,11 +85,12 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
>  		 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
>  		 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
>  		 */
> -		ret = i2c_smbus_read_word_data(data->client, chan->address);
> +		ret = regmap_bulk_read(data->regmap, chan->address, &regval,
> +				       sizeof(regval));
>  		if (ret < 0)
>  			return ret;
>  
> -		*val = sign_extend32(ret, 12);
> +		*val = sign_extend32(le16_to_cpu(regval), 12);
>  		return IIO_VAL_INT;
>  	case IIO_CHAN_INFO_SCALE:
>  		*val = 0;
> @@ -104,37 +112,50 @@ static int adxl345_probe(struct i2c_client *client,
>  {
>  	struct adxl345_data *data;
>  	struct iio_dev *indio_dev;
> +	struct regmap *regmap;
> +	struct device *dev;
> +	u32 regval;
>  	int ret;
>  
> -	ret = i2c_smbus_read_byte_data(client, ADXL345_REG_DEVID);
> +	regmap = devm_regmap_init_i2c(client, &adxl345_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&client->dev, "Error initializing regmap: %ld\n",
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +
> +	dev = regmap_get_device(regmap);
> +
> +	ret = regmap_read(regmap, ADXL345_REG_DEVID, &regval);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "Error reading device ID: %d\n", ret);
> +		dev_err(dev, "Error reading device ID: %d\n", ret);
>  		return ret;
>  	}
>  
> -	if (ret != ADXL345_DEVID) {
> -		dev_err(&client->dev, "Invalid device ID: %d\n", ret);
> +	if (regval != ADXL345_DEVID) {
> +		dev_err(dev, "Invalid device ID: %x, expected %x\n",
> +			regval, ADXL345_DEVID);
>  		return -ENODEV;
>  	}
>  
> -	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
>  	if (!indio_dev)
>  		return -ENOMEM;
>  
>  	data = iio_priv(indio_dev);
> -	i2c_set_clientdata(client, indio_dev);
> -	data->client = client;
> +	dev_set_drvdata(dev, indio_dev);
> +	data->regmap = regmap;
>  	/* Enable full-resolution mode */
>  	data->data_range = ADXL345_DATA_FORMAT_FULL_RES;
>  
> -	ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_DATA_FORMAT,
> -					data->data_range);
> +	ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
> +			   data->data_range);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "Failed to set data range: %d\n", ret);
> +		dev_err(dev, "Failed to set data range: %d\n", ret);
>  		return ret;
>  	}
>  
> -	indio_dev->dev.parent = &client->dev;
> +	indio_dev->dev.parent = dev;
>  	indio_dev->name = id->name;
>  	indio_dev->info = &adxl345_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
> @@ -142,19 +163,18 @@ static int adxl345_probe(struct i2c_client *client,
>  	indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
>  
>  	/* Enable measurement mode */
> -	ret = i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
> -					ADXL345_POWER_CTL_MEASURE);
> +	ret = regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
> +			   ADXL345_POWER_CTL_MEASURE);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "Failed to enable measurement mode: %d\n",
> -			ret);
> +		dev_err(dev, "Failed to enable measurement mode: %d\n", ret);
>  		return ret;
>  	}
>  
>  	ret = iio_device_register(indio_dev);
>  	if (ret < 0) {
> -		dev_err(&client->dev, "iio_device_register failed: %d\n", ret);
> -		i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
> -					  ADXL345_POWER_CTL_STANDBY);
> +		dev_err(dev, "iio_device_register failed: %d\n", ret);
> +		regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
> +			     ADXL345_POWER_CTL_STANDBY);
>  	}
>  
>  	return ret;
> @@ -167,8 +187,8 @@ static int adxl345_remove(struct i2c_client *client)
>  
>  	iio_device_unregister(indio_dev);
>  
> -	return i2c_smbus_write_byte_data(data->client, ADXL345_REG_POWER_CTL,
> -					 ADXL345_POWER_CTL_STANDBY);
> +	return regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
> +			    ADXL345_POWER_CTL_STANDBY);
>  }
>  
>  static const struct i2c_device_id adxl345_i2c_id[] = {
> 

Re: [PATCH v6 3/4] iio: accel: adxl345: Split driver into core and I2C

[Jonathan Cameron]

On 04/03/17 08:31, Eva Rachel Retuya wrote:
> Move I2C-specific code into its own file and rely on regmap to access
> registers. The core code provides access to x, y, z and scale readings.
> 
> Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders
to play with it.

Thanks,

Jonathan
> ---
> Changes from v5:
> * Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
> * Rename functions from *_common_* to *_core_*
> * Modify header comment: place indication at the beginning
> * Remove explicit casting to int in handling devm_regmap_init_i2c() error,
>   use %ld instead
> * Remove temporary variable 'name'
> 
>  drivers/iio/accel/Kconfig                       | 13 +++--
>  drivers/iio/accel/Makefile                      |  3 +-
>  drivers/iio/accel/adxl345.h                     | 18 ++++++
>  drivers/iio/accel/{adxl345.c => adxl345_core.c} | 57 ++++---------------
>  drivers/iio/accel/adxl345_i2c.c                 | 73 +++++++++++++++++++++++++
>  5 files changed, 113 insertions(+), 51 deletions(-)
>  create mode 100644 drivers/iio/accel/adxl345.h
>  rename drivers/iio/accel/{adxl345.c => adxl345_core.c} (77%)
>  create mode 100644 drivers/iio/accel/adxl345_i2c.c
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 26b8614..a725227 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -6,16 +6,21 @@
>  menu "Accelerometers"
>  
>  config ADXL345
> -	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer Driver"
> -	depends on !(INPUT_ADXL34X=y || INPUT_ADXL34X=m)
> +	tristate
> +
> +config ADXL345_I2C
> +	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer I2C Driver"
> +	depends on INPUT_ADXL34X=n
>  	depends on I2C
> +	select ADXL345
>  	select REGMAP_I2C
>  	help
>  	  Say Y here if you want to build support for the Analog Devices
>  	  ADXL345 3-axis digital accelerometer.
>  
> -	  To compile this driver as a module, choose M here: the
> -	  module will be called adxl345.
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called adxl345_i2c and you will also get adxl345_core
> +	  for the core module.
>  
>  config BMA180
>  	tristate "Bosch BMA180/BMA250 3-Axis Accelerometer Driver"
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 618488d..3f4a6d6 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -3,7 +3,8 @@
>  #
>  
>  # When adding new entries keep the list in alphabetical order
> -obj-$(CONFIG_ADXL345) += adxl345.o
> +obj-$(CONFIG_ADXL345) += adxl345_core.o
> +obj-$(CONFIG_ADXL345_I2C) += adxl345_i2c.o
>  obj-$(CONFIG_BMA180) += bma180.o
>  obj-$(CONFIG_BMA220) += bma220_spi.o
>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
> diff --git a/drivers/iio/accel/adxl345.h b/drivers/iio/accel/adxl345.h
> new file mode 100644
> index 0000000..c1ddf39
> --- /dev/null
> +++ b/drivers/iio/accel/adxl345.h
> @@ -0,0 +1,18 @@
> +/*
> + * ADXL345 3-Axis Digital Accelerometer
> + *
> + * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + */
> +
> +#ifndef _ADXL345_H_
> +#define _ADXL345_H_
> +
> +int adxl345_core_probe(struct device *dev, struct regmap *regmap,
> +		       const char *name);
> +int adxl345_core_remove(struct device *dev);
> +
> +#endif /* _ADXL345_H_ */
> diff --git a/drivers/iio/accel/adxl345.c b/drivers/iio/accel/adxl345_core.c
> similarity index 77%
> rename from drivers/iio/accel/adxl345.c
> rename to drivers/iio/accel/adxl345_core.c
> index 87fdd9f..9ccb582 100644
> --- a/drivers/iio/accel/adxl345.c
> +++ b/drivers/iio/accel/adxl345_core.c
> @@ -1,23 +1,20 @@
>  /*
> - * ADXL345 3-Axis Digital Accelerometer
> + * ADXL345 3-Axis Digital Accelerometer IIO core driver
>   *
>   * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
>   *
>   * This file is subject to the terms and conditions of version 2 of
>   * the GNU General Public License. See the file COPYING in the main
>   * directory of this archive for more details.
> - *
> - * IIO driver for ADXL345
> - * 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or
> - * 0x53 (ALT ADDRESS pin grounded)
>   */
>  
> -#include <linux/i2c.h>
>  #include <linux/module.h>
>  #include <linux/regmap.h>
>  
>  #include <linux/iio/iio.h>
>  
> +#include "adxl345.h"
> +
>  #define ADXL345_REG_DEVID		0x00
>  #define ADXL345_REG_POWER_CTL		0x2D
>  #define ADXL345_REG_DATA_FORMAT		0x31
> @@ -50,11 +47,6 @@ struct adxl345_data {
>  	u8 data_range;
>  };
>  
> -static const struct regmap_config adxl345_regmap_config = {
> -	.reg_bits = 8,
> -	.val_bits = 8,
> -};
> -
>  #define ADXL345_CHANNEL(reg, axis) {					\
>  	.type = IIO_ACCEL,						\
>  	.modified = 1,							\
> @@ -107,25 +99,14 @@ static const struct iio_info adxl345_info = {
>  	.read_raw	= adxl345_read_raw,
>  };
>  
> -static int adxl345_probe(struct i2c_client *client,
> -			 const struct i2c_device_id *id)
> +int adxl345_core_probe(struct device *dev, struct regmap *regmap,
> +		       const char *name)
>  {
>  	struct adxl345_data *data;
>  	struct iio_dev *indio_dev;
> -	struct regmap *regmap;
> -	struct device *dev;
>  	u32 regval;
>  	int ret;
>  
> -	regmap = devm_regmap_init_i2c(client, &adxl345_regmap_config);
> -	if (IS_ERR(regmap)) {
> -		dev_err(&client->dev, "Error initializing regmap: %ld\n",
> -			PTR_ERR(regmap));
> -		return PTR_ERR(regmap);
> -	}
> -
> -	dev = regmap_get_device(regmap);
> -
>  	ret = regmap_read(regmap, ADXL345_REG_DEVID, &regval);
>  	if (ret < 0) {
>  		dev_err(dev, "Error reading device ID: %d\n", ret);
> @@ -156,7 +137,7 @@ static int adxl345_probe(struct i2c_client *client,
>  	}
>  
>  	indio_dev->dev.parent = dev;
> -	indio_dev->name = id->name;
> +	indio_dev->name = name;
>  	indio_dev->info = &adxl345_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->channels = adxl345_channels;
> @@ -179,10 +160,11 @@ static int adxl345_probe(struct i2c_client *client,
>  
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(adxl345_core_probe);
>  
> -static int adxl345_remove(struct i2c_client *client)
> +int adxl345_core_remove(struct device *dev)
>  {
> -	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct adxl345_data *data = iio_priv(indio_dev);
>  
>  	iio_device_unregister(indio_dev);
> @@ -190,25 +172,8 @@ static int adxl345_remove(struct i2c_client *client)
>  	return regmap_write(data->regmap, ADXL345_REG_POWER_CTL,
>  			    ADXL345_POWER_CTL_STANDBY);
>  }
> -
> -static const struct i2c_device_id adxl345_i2c_id[] = {
> -	{ "adxl345", 0 },
> -	{ }
> -};
> -
> -MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id);
> -
> -static struct i2c_driver adxl345_driver = {
> -	.driver = {
> -		.name	= "adxl345",
> -	},
> -	.probe		= adxl345_probe,
> -	.remove		= adxl345_remove,
> -	.id_table	= adxl345_i2c_id,
> -};
> -
> -module_i2c_driver(adxl345_driver);
> +EXPORT_SYMBOL_GPL(adxl345_core_remove);
>  
>  MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
> -MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer driver");
> +MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver");
>  MODULE_LICENSE("GPL v2");
> diff --git a/drivers/iio/accel/adxl345_i2c.c b/drivers/iio/accel/adxl345_i2c.c
> new file mode 100644
> index 0000000..05e1ec4
> --- /dev/null
> +++ b/drivers/iio/accel/adxl345_i2c.c
> @@ -0,0 +1,73 @@
> +/*
> + * ADXL345 3-Axis Digital Accelerometer I2C driver
> + *
> + * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * 7-bit I2C slave address: 0x1D (ALT ADDRESS pin tied to VDDIO) or
> + * 0x53 (ALT ADDRESS pin grounded)
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include "adxl345.h"
> +
> +static const struct regmap_config adxl345_i2c_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +};
> +
> +static int adxl345_i2c_probe(struct i2c_client *client,
> +			     const struct i2c_device_id *id)
> +{
> +	struct regmap *regmap;
> +
> +	regmap = devm_regmap_init_i2c(client, &adxl345_i2c_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&client->dev, "Error initializing i2c regmap: %ld\n",
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +
> +	return adxl345_core_probe(&client->dev, regmap, id ? id->name : NULL);
> +}
> +
> +static int adxl345_i2c_remove(struct i2c_client *client)
> +{
> +	return adxl345_core_remove(&client->dev);
> +}
> +
> +static const struct i2c_device_id adxl345_i2c_id[] = {
> +	{ "adxl345", 0 },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, adxl345_i2c_id);
> +
> +static const struct of_device_id adxl345_of_match[] = {
> +	{ .compatible = "adi,adxl345" },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, adxl345_of_match);
> +
> +static struct i2c_driver adxl345_i2c_driver = {
> +	.driver = {
> +		.name	= "adxl345_i2c",
> +		.of_match_table = adxl345_of_match,
> +	},
> +	.probe		= adxl345_i2c_probe,
> +	.remove		= adxl345_i2c_remove,
> +	.id_table	= adxl345_i2c_id,
> +};
> +
> +module_i2c_driver(adxl345_i2c_driver);
> +
> +MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
> +MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer I2C driver");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v6 4/4] iio: accel: adxl345: Add SPI support

[Jonathan Cameron]

On 04/03/17 08:31, Eva Rachel Retuya wrote:
> Add SPI driver that initializes SPI regmap for the adxl345 core driver.
> The driver supports the same functionality as I2C namely the x, y, z and
> scale readings.
> 
> Signed-off-by: Eva Rachel Retuya <eraretuya@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Applied to the togreg branch og iio.git and pushed out as testing.

Thanks,

Jonathan
> ---
> Changes from v5:
> * Simplify configuration dependency to "depends on INPUT_ADXL34X=n"
> * Modify header comment: place indication at the beginning
> * Re-order local variable declarations from longest to shortest line
> * Remove explicit casting to int in handling devm_regmap_init_spi() error,
>   use %ld instead
> * Rename functions calls from *_common_* to *_core_*
> 
>  drivers/iio/accel/Kconfig       | 14 +++++++
>  drivers/iio/accel/Makefile      |  1 +
>  drivers/iio/accel/adxl345_spi.c | 81 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 96 insertions(+)
>  create mode 100644 drivers/iio/accel/adxl345_spi.c
> 
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index a725227..15de262 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -22,6 +22,20 @@ config ADXL345_I2C
>  	  will be called adxl345_i2c and you will also get adxl345_core
>  	  for the core module.
>  
> +config ADXL345_SPI
> +	tristate "Analog Devices ADXL345 3-Axis Digital Accelerometer SPI Driver"
> +	depends on INPUT_ADXL34X=n
> +	depends on SPI
> +	select ADXL345
> +	select REGMAP_SPI
> +	help
> +	  Say Y here if you want to build support for the Analog Devices
> +	  ADXL345 3-axis digital accelerometer.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called adxl345_spi and you will also get adxl345_core
> +	  for the core module.
> +
>  config BMA180
>  	tristate "Bosch BMA180/BMA250 3-Axis Accelerometer Driver"
>  	depends on I2C
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 3f4a6d6..31fba19 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -5,6 +5,7 @@
>  # When adding new entries keep the list in alphabetical order
>  obj-$(CONFIG_ADXL345) += adxl345_core.o
>  obj-$(CONFIG_ADXL345_I2C) += adxl345_i2c.o
> +obj-$(CONFIG_ADXL345_SPI) += adxl345_spi.o
>  obj-$(CONFIG_BMA180) += bma180.o
>  obj-$(CONFIG_BMA220) += bma220_spi.o
>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
> diff --git a/drivers/iio/accel/adxl345_spi.c b/drivers/iio/accel/adxl345_spi.c
> new file mode 100644
> index 0000000..6d65819
> --- /dev/null
> +++ b/drivers/iio/accel/adxl345_spi.c
> @@ -0,0 +1,81 @@
> +/*
> + * ADXL345 3-Axis Digital Accelerometer SPI driver
> + *
> + * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/spi/spi.h>
> +
> +#include "adxl345.h"
> +
> +#define ADXL345_MAX_SPI_FREQ_HZ		5000000
> +
> +static const struct regmap_config adxl345_spi_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	 /* Setting bits 7 and 6 enables multiple-byte read */
> +	.read_flag_mask = BIT(7) | BIT(6),
> +};
> +
> +static int adxl345_spi_probe(struct spi_device *spi)
> +{
> +	const struct spi_device_id *id = spi_get_device_id(spi);
> +	struct regmap *regmap;
> +
> +	/* Bail out if max_speed_hz exceeds 5 MHz */
> +	if (spi->max_speed_hz > ADXL345_MAX_SPI_FREQ_HZ) {
> +		dev_err(&spi->dev, "SPI CLK, %d Hz exceeds 5 MHz\n",
> +			spi->max_speed_hz);
> +		return -EINVAL;
> +	}
> +
> +	regmap = devm_regmap_init_spi(spi, &adxl345_spi_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",
> +			PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +
> +	return adxl345_core_probe(&spi->dev, regmap, id->name);
> +}
> +
> +static int adxl345_spi_remove(struct spi_device *spi)
> +{
> +	return adxl345_core_remove(&spi->dev);
> +}
> +
> +static const struct spi_device_id adxl345_spi_id[] = {
> +	{ "adxl345", 0 },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(spi, adxl345_spi_id);
> +
> +static const struct of_device_id adxl345_of_match[] = {
> +	{ .compatible = "adi,adxl345" },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, adxl345_of_match);
> +
> +static struct spi_driver adxl345_spi_driver = {
> +	.driver = {
> +		.name	= "adxl345_spi",
> +		.of_match_table = adxl345_of_match,
> +	},
> +	.probe		= adxl345_spi_probe,
> +	.remove		= adxl345_spi_remove,
> +	.id_table	= adxl345_spi_id,
> +};
> +
> +module_spi_driver(adxl345_spi_driver);
> +
> +MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
> +MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer SPI driver");
> +MODULE_LICENSE("GPL v2");
>