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* [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
@ 2016-09-22 13:42 Hans de Goede
  2016-09-22 17:10 ` Jonathan Cameron
  2016-09-25 15:11 ` Lars-Peter Clausen
  0 siblings, 2 replies; 6+ messages in thread
From: Hans de Goede @ 2016-09-22 13:42 UTC (permalink / raw)
  To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
	Peter Meerwald
  Cc: linux-iio, Hans de Goede

This driver is based on the DA311 Android driver which can be found here:
https://git.matricom.net/Firmware/kernel_amlogic_meson-common/tree/1e70113a5befd07debb68f537156def84c5be57a/drivers/amlogic/input/sensor
the mir3da_* files are the DA311 driver.

Unfortunately there is no datasheet.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
-Add proper prefix to patch Subject
-Use i2c_smbus_read_word_data() instead of i2c_smbus_read_i2c_block_data()
---
 .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
 drivers/iio/accel/Kconfig                          |  10 +
 drivers/iio/accel/Makefile                         |   1 +
 drivers/iio/accel/da311.c                          | 305 +++++++++++++++++++++
 4 files changed, 317 insertions(+)
 create mode 100644 drivers/iio/accel/da311.c

diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
index 21ca02e..8ad9064 100644
--- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
+++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
@@ -122,6 +122,7 @@ microchip,mcp4662-502	Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem
 microchip,mcp4662-103	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k)
 microchip,mcp4662-503	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k)
 microchip,mcp4662-104	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k)
+miramems,da311		MiraMEMS DA311 3-axis 12-bit digital accelerometer
 national,lm63		Temperature sensor with integrated fan control
 national,lm75		I2C TEMP SENSOR
 national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 6236fd5..c94348f 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -52,6 +52,16 @@ config BMC150_ACCEL_SPI
 	tristate
 	select REGMAP_SPI
 
+config DA311
+	tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
+	depends on I2C
+	help
+	  Say yes here to build support for the MiraMEMS DA311 3-axis 12-bit
+	  digital accelerometer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called da311.
+
 config DMARD06
 	tristate "Domintech DMARD06 Digital Accelerometer Driver"
 	depends on OF || COMPILE_TEST
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 9f51559..601ca59 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_BMA220) += bma220_spi.o
 obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
 obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
 obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
+obj-$(CONFIG_DA311)	+= da311.o
 obj-$(CONFIG_DMARD06)	+= dmard06.o
 obj-$(CONFIG_DMARD09)	+= dmard09.o
 obj-$(CONFIG_DMARD10)	+= dmard10.o
diff --git a/drivers/iio/accel/da311.c b/drivers/iio/accel/da311.c
new file mode 100644
index 0000000..8c852f5
--- /dev/null
+++ b/drivers/iio/accel/da311.c
@@ -0,0 +1,305 @@
+/**
+ * IIO driver for the MiraMEMS DA311 3-axis accelerometer
+ *
+ * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
+ * Copyright (c) 2011-2013 MiraMEMS Sensing Technology Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/byteorder/generic.h>
+
+#define DA311_CHIP_ID			0x13
+
+/*
+ * Note register addressed go from 0 - 0x3f and then wrap.
+ * For some reason there are 2 banks with 0 - 0x3f addresses,
+ * rather then a single 0-0x7f bank.
+ */
+
+/* Bank 0 regs */
+#define DA311_REG_BANK			0x0000
+#define DA311_REG_LDO_REG		0x0006
+#define DA311_REG_CHIP_ID		0x000f
+#define DA311_REG_TEMP_CFG_REG		0x001f
+#define DA311_REG_CTRL_REG1		0x0020
+#define DA311_REG_CTRL_REG3		0x0022
+#define DA311_REG_CTRL_REG4		0x0023
+#define DA311_REG_CTRL_REG5		0x0024
+#define DA311_REG_CTRL_REG6		0x0025
+#define DA311_REG_STATUS_REG		0x0027
+#define DA311_REG_OUT_X_L		0x0028
+#define DA311_REG_OUT_X_H		0x0029
+#define DA311_REG_OUT_Y_L		0x002a
+#define DA311_REG_OUT_Y_H		0x002b
+#define DA311_REG_OUT_Z_L		0x002c
+#define DA311_REG_OUT_Z_H		0x002d
+#define DA311_REG_INT1_CFG		0x0030
+#define DA311_REG_INT1_SRC		0x0031
+#define DA311_REG_INT1_THS		0x0032
+#define DA311_REG_INT1_DURATION		0x0033
+#define DA311_REG_INT2_CFG		0x0034
+#define DA311_REG_INT2_SRC		0x0035
+#define DA311_REG_INT2_THS		0x0036
+#define DA311_REG_INT2_DURATION		0x0037
+#define DA311_REG_CLICK_CFG		0x0038
+#define DA311_REG_CLICK_SRC		0x0039
+#define DA311_REG_CLICK_THS		0x003a
+#define DA311_REG_TIME_LIMIT		0x003b
+#define DA311_REG_TIME_LATENCY		0x003c
+#define DA311_REG_TIME_WINDOW		0x003d
+
+/* Bank 1 regs */
+#define DA311_REG_SOFT_RESET		0x0105
+#define DA311_REG_OTP_XOFF_L		0x0110
+#define DA311_REG_OTP_XOFF_H		0x0111
+#define DA311_REG_OTP_YOFF_L		0x0112
+#define DA311_REG_OTP_YOFF_H		0x0113
+#define DA311_REG_OTP_ZOFF_L		0x0114
+#define DA311_REG_OTP_ZOFF_H		0x0115
+#define DA311_REG_OTP_XSO		0x0116
+#define DA311_REG_OTP_YSO		0x0117
+#define DA311_REG_OTP_ZSO		0x0118
+#define DA311_REG_OTP_TRIM_OSC		0x011b
+#define DA311_REG_LPF_ABSOLUTE		0x011c
+#define DA311_REG_TEMP_OFF1		0x0127
+#define DA311_REG_TEMP_OFF2		0x0128
+#define DA311_REG_TEMP_OFF3		0x0129
+#define DA311_REG_OTP_TRIM_THERM_H	0x011a
+
+/*
+ * a value of + or -1024 corresponds to + or - 1G
+ * scale = 1 / 1024 = 0.000976562
+ */
+
+static const int da311_nscale = 976562;
+
+#define DA311_CHANNEL(reg, axis) {	\
+	.type = IIO_ACCEL,	\
+	.address = reg,	\
+	.modified = 1,	\
+	.channel2 = IIO_MOD_##axis,	\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec da311_channels[] = {
+	/* | 0x80 comes from the android driver */
+	DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
+	DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
+	DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
+};
+
+struct da311_data {
+	struct i2c_client *client;
+};
+
+static int da311_register_mask_write(struct i2c_client *client, u16 addr,
+				     u8 mask, u8 data)
+{
+	int ret;
+	u8 tmp_data = 0;
+
+	if (addr & 0xff00) {
+		/* Select bank 1 */
+		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (mask != 0xff) {
+		ret = i2c_smbus_read_byte_data(client, addr);
+		if (ret < 0)
+			return ret;
+		tmp_data = ret;
+	}
+
+	tmp_data &= ~mask;
+	tmp_data |= data & mask;
+	ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
+	if (ret < 0)
+		return ret;
+
+	if (addr & 0xff00) {
+		/* Back to bank 0 */
+		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* Init sequence taken from the android driver */
+static int da311_reset(struct i2c_client *client)
+{
+	const struct {
+		u16 addr;
+		u8 mask;
+		u8 data;
+	} init_data[] = {
+		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
+		{ DA311_REG_CTRL_REG5,          0xff,   0x80 },
+		{ DA311_REG_CTRL_REG4,          0x30,   0x00 },
+		{ DA311_REG_CTRL_REG1,          0xff,   0x6f },
+		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
+		{ DA311_REG_LDO_REG,            0xff,   0x02 },
+		{ DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
+		{ DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
+		{ DA311_REG_TEMP_OFF1,          0xff,   0x3f },
+		{ DA311_REG_TEMP_OFF2,          0xff,   0xff },
+		{ DA311_REG_TEMP_OFF3,          0xff,   0x0f },
+	};
+	int i, ret;
+
+	/* Reset */
+	ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
+					0xff, 0xaa);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
+		ret = da311_register_mask_write(client,
+						init_data[i].addr,
+						init_data[i].mask,
+						init_data[i].data);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int da311_enable(struct i2c_client *client, bool enable)
+{
+	u8 data = enable ? 0x00 : 0x20;
+
+	return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
+					 0x20, data);
+}
+
+static int da311_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct da311_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = i2c_smbus_read_word_data(data->client, chan->address);
+		if (ret < 0)
+			return ret;
+		/*
+		 * Values are 12 bits, stored as 16 bits with the 4
+		 * least significant bits always 0.
+		 */
+		*val = ((short)le16_to_cpu(ret)) >> 4;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = da311_nscale;
+		return IIO_VAL_INT_PLUS_NANO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info da311_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= da311_read_raw,
+};
+
+static int da311_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct da311_data *data;
+
+	ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
+	if (ret != DA311_CHIP_ID)
+		return (ret < 0) ? ret : -ENODEV;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	i2c_set_clientdata(client, indio_dev);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &da311_info;
+	indio_dev->name = "da311";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = da311_channels;
+	indio_dev->num_channels = ARRAY_SIZE(da311_channels);
+
+	ret = da311_reset(client);
+	if (ret < 0)
+		return ret;
+
+	ret = da311_enable(client, true);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "device_register failed\n");
+		da311_enable(client, false);
+	}
+
+	return ret;
+}
+
+static int da311_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return da311_enable(client, false);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int da311_suspend(struct device *dev)
+{
+	return da311_enable(to_i2c_client(dev), false);
+}
+
+static int da311_resume(struct device *dev)
+{
+	return da311_enable(to_i2c_client(dev), true);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);
+
+static const struct i2c_device_id da311_i2c_id[] = {
+	{"da311", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, da311_i2c_id);
+
+static struct i2c_driver da311_driver = {
+	.driver = {
+		.name = "da311",
+		.pm = &da311_pm_ops,
+	},
+	.probe		= da311_probe,
+	.remove		= da311_remove,
+	.id_table	= da311_i2c_id,
+};
+
+module_i2c_driver(da311_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
-- 
2.9.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
  2016-09-22 13:42 [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer Hans de Goede
@ 2016-09-22 17:10 ` Jonathan Cameron
  2016-09-23 13:51   ` Hans de Goede
  2016-09-25 15:11 ` Lars-Peter Clausen
  1 sibling, 1 reply; 6+ messages in thread
From: Jonathan Cameron @ 2016-09-22 17:10 UTC (permalink / raw)
  To: Hans de Goede, Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald
  Cc: linux-iio

On 22/09/16 14:42, Hans de Goede wrote:
> This driver is based on the DA311 Android driver which can be found here:
> https://git.matricom.net/Firmware/kernel_amlogic_meson-common/tree/1e70113a5befd07debb68f537156def84c5be57a/drivers/amlogic/input/sensor
> the mir3da_* files are the DA311 driver.
> 
> Unfortunately there is no datasheet.
>
I was crossing my fingers that it was similar to the 312 which does have
a datasheet on their website. No such luck.

Looks good. Couple of really minor comment inline. I'd like this to sit
on the mailing list a bit longer. Unfortunately it's just missed the
upcoming merge window so we have lots and lots of time :)

Jonathan

> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> -Add proper prefix to patch Subject
> -Use i2c_smbus_read_word_data() instead of i2c_smbus_read_i2c_block_data()
> ---
>  .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>  drivers/iio/accel/Kconfig                          |  10 +
>  drivers/iio/accel/Makefile                         |   1 +
>  drivers/iio/accel/da311.c                          | 305 +++++++++++++++++++++
>  4 files changed, 317 insertions(+)
>  create mode 100644 drivers/iio/accel/da311.c
> 
> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
> index 21ca02e..8ad9064 100644
> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
> @@ -122,6 +122,7 @@ microchip,mcp4662-502	Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem
>  microchip,mcp4662-103	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k)
>  microchip,mcp4662-503	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k)
>  microchip,mcp4662-104	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k)
> +miramems,da311		MiraMEMS DA311 3-axis 12-bit digital accelerometer
>  national,lm63		Temperature sensor with integrated fan control
>  national,lm75		I2C TEMP SENSOR
>  national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 6236fd5..c94348f 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -52,6 +52,16 @@ config BMC150_ACCEL_SPI
>  	tristate
>  	select REGMAP_SPI
>  
> +config DA311
> +	tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
> +	depends on I2C
> +	help
> +	  Say yes here to build support for the MiraMEMS DA311 3-axis 12-bit
> +	  digital accelerometer.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called da311.
> +
>  config DMARD06
>  	tristate "Domintech DMARD06 Digital Accelerometer Driver"
>  	depends on OF || COMPILE_TEST
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 9f51559..601ca59 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_BMA220) += bma220_spi.o
>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
>  obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
>  obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
> +obj-$(CONFIG_DA311)	+= da311.o
>  obj-$(CONFIG_DMARD06)	+= dmard06.o
>  obj-$(CONFIG_DMARD09)	+= dmard09.o
>  obj-$(CONFIG_DMARD10)	+= dmard10.o
> diff --git a/drivers/iio/accel/da311.c b/drivers/iio/accel/da311.c
> new file mode 100644
> index 0000000..8c852f5
> --- /dev/null
> +++ b/drivers/iio/accel/da311.c
> @@ -0,0 +1,305 @@
> +/**
> + * IIO driver for the MiraMEMS DA311 3-axis accelerometer
> + *
> + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
> + * Copyright (c) 2011-2013 MiraMEMS Sensing Technology Co., Ltd.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/byteorder/generic.h>
> +
> +#define DA311_CHIP_ID			0x13
> +
> +/*
> + * Note register addressed go from 0 - 0x3f and then wrap.
> + * For some reason there are 2 banks with 0 - 0x3f addresses,
> + * rather then a single 0-0x7f bank.
> + */
> +
> +/* Bank 0 regs */
> +#define DA311_REG_BANK			0x0000
> +#define DA311_REG_LDO_REG		0x0006
> +#define DA311_REG_CHIP_ID		0x000f
> +#define DA311_REG_TEMP_CFG_REG		0x001f
> +#define DA311_REG_CTRL_REG1		0x0020
> +#define DA311_REG_CTRL_REG3		0x0022
> +#define DA311_REG_CTRL_REG4		0x0023
> +#define DA311_REG_CTRL_REG5		0x0024
> +#define DA311_REG_CTRL_REG6		0x0025
> +#define DA311_REG_STATUS_REG		0x0027
> +#define DA311_REG_OUT_X_L		0x0028
> +#define DA311_REG_OUT_X_H		0x0029
> +#define DA311_REG_OUT_Y_L		0x002a
> +#define DA311_REG_OUT_Y_H		0x002b
> +#define DA311_REG_OUT_Z_L		0x002c
> +#define DA311_REG_OUT_Z_H		0x002d
> +#define DA311_REG_INT1_CFG		0x0030
> +#define DA311_REG_INT1_SRC		0x0031
> +#define DA311_REG_INT1_THS		0x0032
> +#define DA311_REG_INT1_DURATION		0x0033
> +#define DA311_REG_INT2_CFG		0x0034
> +#define DA311_REG_INT2_SRC		0x0035
> +#define DA311_REG_INT2_THS		0x0036
> +#define DA311_REG_INT2_DURATION		0x0037
> +#define DA311_REG_CLICK_CFG		0x0038
> +#define DA311_REG_CLICK_SRC		0x0039
> +#define DA311_REG_CLICK_THS		0x003a
> +#define DA311_REG_TIME_LIMIT		0x003b
> +#define DA311_REG_TIME_LATENCY		0x003c
> +#define DA311_REG_TIME_WINDOW		0x003d
> +
> +/* Bank 1 regs */
> +#define DA311_REG_SOFT_RESET		0x0105
> +#define DA311_REG_OTP_XOFF_L		0x0110
> +#define DA311_REG_OTP_XOFF_H		0x0111
> +#define DA311_REG_OTP_YOFF_L		0x0112
> +#define DA311_REG_OTP_YOFF_H		0x0113
> +#define DA311_REG_OTP_ZOFF_L		0x0114
> +#define DA311_REG_OTP_ZOFF_H		0x0115
> +#define DA311_REG_OTP_XSO		0x0116
> +#define DA311_REG_OTP_YSO		0x0117
> +#define DA311_REG_OTP_ZSO		0x0118
> +#define DA311_REG_OTP_TRIM_OSC		0x011b
> +#define DA311_REG_LPF_ABSOLUTE		0x011c
> +#define DA311_REG_TEMP_OFF1		0x0127
> +#define DA311_REG_TEMP_OFF2		0x0128
> +#define DA311_REG_TEMP_OFF3		0x0129
> +#define DA311_REG_OTP_TRIM_THERM_H	0x011a
> +
> +/*
> + * a value of + or -1024 corresponds to + or - 1G
> + * scale = 1 / 1024 = 0.000976562
> + */
> +
> +static const int da311_nscale = 976562;
> +
> +#define DA311_CHANNEL(reg, axis) {	\
> +	.type = IIO_ACCEL,	\
> +	.address = reg,	\
> +	.modified = 1,	\
> +	.channel2 = IIO_MOD_##axis,	\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +}
> +
> +static const struct iio_chan_spec da311_channels[] = {
> +	/* | 0x80 comes from the android driver */
> +	DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
> +	DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
> +	DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
> +};
> +
> +struct da311_data {
> +	struct i2c_client *client;
> +};
> +
> +static int da311_register_mask_write(struct i2c_client *client, u16 addr,
> +				     u8 mask, u8 data)
> +{
> +	int ret;
> +	u8 tmp_data = 0;
> +
> +	if (addr & 0xff00) {
> +		/* Select bank 1 */
> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	if (mask != 0xff) {
> +		ret = i2c_smbus_read_byte_data(client, addr);
> +		if (ret < 0)
> +			return ret;
> +		tmp_data = ret;
> +	}
> +
> +	tmp_data &= ~mask;
> +	tmp_data |= data & mask;
> +	ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (addr & 0xff00) {
> +		/* Back to bank 0 */
> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/* Init sequence taken from the android driver */
> +static int da311_reset(struct i2c_client *client)
> +{
> +	const struct {
> +		u16 addr;
> +		u8 mask;
> +		u8 data;
> +	} init_data[] = {
> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
> +		{ DA311_REG_CTRL_REG5,          0xff,   0x80 },
> +		{ DA311_REG_CTRL_REG4,          0x30,   0x00 },
> +		{ DA311_REG_CTRL_REG1,          0xff,   0x6f },
> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
> +		{ DA311_REG_LDO_REG,            0xff,   0x02 },
> +		{ DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
> +		{ DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
> +		{ DA311_REG_TEMP_OFF1,          0xff,   0x3f },
> +		{ DA311_REG_TEMP_OFF2,          0xff,   0xff },
> +		{ DA311_REG_TEMP_OFF3,          0xff,   0x0f },
Nice ;)  Not much we can do about this without a datasheet. Ah well.
> +	};
> +	int i, ret;
> +
> +	/* Reset */
> +	ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
> +					0xff, 0xaa);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
> +		ret = da311_register_mask_write(client,
> +						init_data[i].addr,
> +						init_data[i].mask,
> +						init_data[i].data);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int da311_enable(struct i2c_client *client, bool enable)
> +{
> +	u8 data = enable ? 0x00 : 0x20;
This feels ever so slightly like a magic number that ought to be
a define rather than inline.  Probably using BIT(5) to define it.
I guess this would be more obvious if we had a datasheet to tell us
what to call it etc.
> +
> +	return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
> +					 0x20, data);
> +}
> +
> +static int da311_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	struct da311_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
> +		if (ret < 0)
> +			return ret;
> +		/*
> +		 * Values are 12 bits, stored as 16 bits with the 4
> +		 * least significant bits always 0.
> +		 */
> +		*val = ((short)le16_to_cpu(ret)) >> 4;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;
> +		*val2 = da311_nscale;
> +		return IIO_VAL_INT_PLUS_NANO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_info da311_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= da311_read_raw,
> +};
> +
> +static int da311_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	int ret;
> +	struct iio_dev *indio_dev;
> +	struct da311_data *data;
> +
> +	ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
> +	if (ret != DA311_CHIP_ID)
> +		return (ret < 0) ? ret : -ENODEV;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	data->client = client;
> +	i2c_set_clientdata(client, indio_dev);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &da311_info;
> +	indio_dev->name = "da311";
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = da311_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(da311_channels);
> +
> +	ret = da311_reset(client);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = da311_enable(client, true);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "device_register failed\n");
> +		da311_enable(client, false);
> +	}
> +
> +	return ret;
> +}
> +
> +static int da311_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	return da311_enable(client, false);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int da311_suspend(struct device *dev)
> +{
> +	return da311_enable(to_i2c_client(dev), false);
> +}
> +
> +static int da311_resume(struct device *dev)
> +{
> +	return da311_enable(to_i2c_client(dev), true);
> +}
> +#endif
I'd just go with the __maybe_unused option rather than the
define protection.
> +
> +static SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);
> +
> +static const struct i2c_device_id da311_i2c_id[] = {
> +	{"da311", 0},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, da311_i2c_id);
> +
> +static struct i2c_driver da311_driver = {
> +	.driver = {
> +		.name = "da311",
> +		.pm = &da311_pm_ops,
> +	},
> +	.probe		= da311_probe,
> +	.remove		= da311_remove,
> +	.id_table	= da311_i2c_id,
> +};
> +
> +module_i2c_driver(da311_driver);
> +
> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
> +MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
> +MODULE_LICENSE("GPL v2");
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
  2016-09-22 17:10 ` Jonathan Cameron
@ 2016-09-23 13:51   ` Hans de Goede
  2016-09-24 16:46     ` Jonathan Cameron
  0 siblings, 1 reply; 6+ messages in thread
From: Hans de Goede @ 2016-09-23 13:51 UTC (permalink / raw)
  To: Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
	Peter Meerwald
  Cc: linux-iio

Hi,

On 09/22/2016 08:10 PM, Jonathan Cameron wrote:
> On 22/09/16 14:42, Hans de Goede wrote:
>> This driver is based on the DA311 Android driver which can be found here:
>> https://git.matricom.net/Firmware/kernel_amlogic_meson-common/tree/1e70113a5befd07debb68f537156def84c5be57a/drivers/amlogic/input/sensor
>> the mir3da_* files are the DA311 driver.
>>
>> Unfortunately there is no datasheet.
>>
> I was crossing my fingers that it was similar to the 312 which does have
> a datasheet on their website. No such luck.

Yeah, I also looked at the da312 datasheet, but no luck indeed.

> Looks good. Couple of really minor comment inline. I'd like this to sit
> on the mailing list a bit longer. Unfortunately it's just missed the
> upcoming merge window so we have lots and lots of time :)
>
> Jonathan
>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> Changes in v2:
>> -Add proper prefix to patch Subject
>> -Use i2c_smbus_read_word_data() instead of i2c_smbus_read_i2c_block_data()
>> ---
>>  .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>  drivers/iio/accel/Kconfig                          |  10 +
>>  drivers/iio/accel/Makefile                         |   1 +
>>  drivers/iio/accel/da311.c                          | 305 +++++++++++++++++++++
>>  4 files changed, 317 insertions(+)
>>  create mode 100644 drivers/iio/accel/da311.c
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> index 21ca02e..8ad9064 100644
>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>> @@ -122,6 +122,7 @@ microchip,mcp4662-502	Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem
>>  microchip,mcp4662-103	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k)
>>  microchip,mcp4662-503	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k)
>>  microchip,mcp4662-104	Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k)
>> +miramems,da311		MiraMEMS DA311 3-axis 12-bit digital accelerometer
>>  national,lm63		Temperature sensor with integrated fan control
>>  national,lm75		I2C TEMP SENSOR
>>  national,lm80		Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 6236fd5..c94348f 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -52,6 +52,16 @@ config BMC150_ACCEL_SPI
>>  	tristate
>>  	select REGMAP_SPI
>>
>> +config DA311
>> +	tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
>> +	depends on I2C
>> +	help
>> +	  Say yes here to build support for the MiraMEMS DA311 3-axis 12-bit
>> +	  digital accelerometer.
>> +
>> +	  To compile this driver as a module, choose M here: the
>> +	  module will be called da311.
>> +
>>  config DMARD06
>>  	tristate "Domintech DMARD06 Digital Accelerometer Driver"
>>  	depends on OF || COMPILE_TEST
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 9f51559..601ca59 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -8,6 +8,7 @@ obj-$(CONFIG_BMA220) += bma220_spi.o
>>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
>>  obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
>>  obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
>> +obj-$(CONFIG_DA311)	+= da311.o
>>  obj-$(CONFIG_DMARD06)	+= dmard06.o
>>  obj-$(CONFIG_DMARD09)	+= dmard09.o
>>  obj-$(CONFIG_DMARD10)	+= dmard10.o
>> diff --git a/drivers/iio/accel/da311.c b/drivers/iio/accel/da311.c
>> new file mode 100644
>> index 0000000..8c852f5
>> --- /dev/null
>> +++ b/drivers/iio/accel/da311.c
>> @@ -0,0 +1,305 @@
>> +/**
>> + * IIO driver for the MiraMEMS DA311 3-axis accelerometer
>> + *
>> + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
>> + * Copyright (c) 2011-2013 MiraMEMS Sensing Technology Co., Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms and conditions of the GNU General Public License,
>> + * version 2, as published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/i2c.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/byteorder/generic.h>
>> +
>> +#define DA311_CHIP_ID			0x13
>> +
>> +/*
>> + * Note register addressed go from 0 - 0x3f and then wrap.
>> + * For some reason there are 2 banks with 0 - 0x3f addresses,
>> + * rather then a single 0-0x7f bank.
>> + */
>> +
>> +/* Bank 0 regs */
>> +#define DA311_REG_BANK			0x0000
>> +#define DA311_REG_LDO_REG		0x0006
>> +#define DA311_REG_CHIP_ID		0x000f
>> +#define DA311_REG_TEMP_CFG_REG		0x001f
>> +#define DA311_REG_CTRL_REG1		0x0020
>> +#define DA311_REG_CTRL_REG3		0x0022
>> +#define DA311_REG_CTRL_REG4		0x0023
>> +#define DA311_REG_CTRL_REG5		0x0024
>> +#define DA311_REG_CTRL_REG6		0x0025
>> +#define DA311_REG_STATUS_REG		0x0027
>> +#define DA311_REG_OUT_X_L		0x0028
>> +#define DA311_REG_OUT_X_H		0x0029
>> +#define DA311_REG_OUT_Y_L		0x002a
>> +#define DA311_REG_OUT_Y_H		0x002b
>> +#define DA311_REG_OUT_Z_L		0x002c
>> +#define DA311_REG_OUT_Z_H		0x002d
>> +#define DA311_REG_INT1_CFG		0x0030
>> +#define DA311_REG_INT1_SRC		0x0031
>> +#define DA311_REG_INT1_THS		0x0032
>> +#define DA311_REG_INT1_DURATION		0x0033
>> +#define DA311_REG_INT2_CFG		0x0034
>> +#define DA311_REG_INT2_SRC		0x0035
>> +#define DA311_REG_INT2_THS		0x0036
>> +#define DA311_REG_INT2_DURATION		0x0037
>> +#define DA311_REG_CLICK_CFG		0x0038
>> +#define DA311_REG_CLICK_SRC		0x0039
>> +#define DA311_REG_CLICK_THS		0x003a
>> +#define DA311_REG_TIME_LIMIT		0x003b
>> +#define DA311_REG_TIME_LATENCY		0x003c
>> +#define DA311_REG_TIME_WINDOW		0x003d
>> +
>> +/* Bank 1 regs */
>> +#define DA311_REG_SOFT_RESET		0x0105
>> +#define DA311_REG_OTP_XOFF_L		0x0110
>> +#define DA311_REG_OTP_XOFF_H		0x0111
>> +#define DA311_REG_OTP_YOFF_L		0x0112
>> +#define DA311_REG_OTP_YOFF_H		0x0113
>> +#define DA311_REG_OTP_ZOFF_L		0x0114
>> +#define DA311_REG_OTP_ZOFF_H		0x0115
>> +#define DA311_REG_OTP_XSO		0x0116
>> +#define DA311_REG_OTP_YSO		0x0117
>> +#define DA311_REG_OTP_ZSO		0x0118
>> +#define DA311_REG_OTP_TRIM_OSC		0x011b
>> +#define DA311_REG_LPF_ABSOLUTE		0x011c
>> +#define DA311_REG_TEMP_OFF1		0x0127
>> +#define DA311_REG_TEMP_OFF2		0x0128
>> +#define DA311_REG_TEMP_OFF3		0x0129
>> +#define DA311_REG_OTP_TRIM_THERM_H	0x011a
>> +
>> +/*
>> + * a value of + or -1024 corresponds to + or - 1G
>> + * scale = 1 / 1024 = 0.000976562
>> + */
>> +
>> +static const int da311_nscale = 976562;
>> +
>> +#define DA311_CHANNEL(reg, axis) {	\
>> +	.type = IIO_ACCEL,	\
>> +	.address = reg,	\
>> +	.modified = 1,	\
>> +	.channel2 = IIO_MOD_##axis,	\
>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
>> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
>> +}
>> +
>> +static const struct iio_chan_spec da311_channels[] = {
>> +	/* | 0x80 comes from the android driver */
>> +	DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
>> +	DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
>> +	DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
>> +};
>> +
>> +struct da311_data {
>> +	struct i2c_client *client;
>> +};
>> +
>> +static int da311_register_mask_write(struct i2c_client *client, u16 addr,
>> +				     u8 mask, u8 data)
>> +{
>> +	int ret;
>> +	u8 tmp_data = 0;
>> +
>> +	if (addr & 0xff00) {
>> +		/* Select bank 1 */
>> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	if (mask != 0xff) {
>> +		ret = i2c_smbus_read_byte_data(client, addr);
>> +		if (ret < 0)
>> +			return ret;
>> +		tmp_data = ret;
>> +	}
>> +
>> +	tmp_data &= ~mask;
>> +	tmp_data |= data & mask;
>> +	ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	if (addr & 0xff00) {
>> +		/* Back to bank 0 */
>> +		ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +/* Init sequence taken from the android driver */
>> +static int da311_reset(struct i2c_client *client)
>> +{
>> +	const struct {
>> +		u16 addr;
>> +		u8 mask;
>> +		u8 data;
>> +	} init_data[] = {
>> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
>> +		{ DA311_REG_CTRL_REG5,          0xff,   0x80 },
>> +		{ DA311_REG_CTRL_REG4,          0x30,   0x00 },
>> +		{ DA311_REG_CTRL_REG1,          0xff,   0x6f },
>> +		{ DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
>> +		{ DA311_REG_LDO_REG,            0xff,   0x02 },
>> +		{ DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
>> +		{ DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
>> +		{ DA311_REG_TEMP_OFF1,          0xff,   0x3f },
>> +		{ DA311_REG_TEMP_OFF2,          0xff,   0xff },
>> +		{ DA311_REG_TEMP_OFF3,          0xff,   0x0f },
> Nice ;)  Not much we can do about this without a datasheet. Ah well.

Yes, ah well indeed.

>> +	};
>> +	int i, ret;
>> +
>> +	/* Reset */
>> +	ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
>> +					0xff, 0xaa);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	for (i = 0; i < ARRAY_SIZE(init_data); i++) {
>> +		ret = da311_register_mask_write(client,
>> +						init_data[i].addr,
>> +						init_data[i].mask,
>> +						init_data[i].data);
>> +		if (ret < 0)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int da311_enable(struct i2c_client *client, bool enable)
>> +{
>> +	u8 data = enable ? 0x00 : 0x20;
> This feels ever so slightly like a magic number that ought to be
> a define rather than inline.  Probably using BIT(5) to define it.
> I guess this would be more obvious if we had a datasheet to tell us
> what to call it etc.

The problem is we've no clue what to call the define, so I would
prefer to just keep this as is.

>> +
>> +	return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
>> +					 0x20, data);
>> +}
>> +
>> +static int da311_read_raw(struct iio_dev *indio_dev,
>> +				struct iio_chan_spec const *chan,
>> +				int *val, int *val2, long mask)
>> +{
>> +	struct da311_data *data = iio_priv(indio_dev);
>> +	int ret;
>> +
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
>> +		if (ret < 0)
>> +			return ret;
>> +		/*
>> +		 * Values are 12 bits, stored as 16 bits with the 4
>> +		 * least significant bits always 0.
>> +		 */
>> +		*val = ((short)le16_to_cpu(ret)) >> 4;
>> +		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SCALE:
>> +		*val = 0;
>> +		*val2 = da311_nscale;
>> +		return IIO_VAL_INT_PLUS_NANO;
>> +	default:
>> +		return -EINVAL;
>> +	}
>> +}
>> +
>> +static const struct iio_info da311_info = {
>> +	.driver_module	= THIS_MODULE,
>> +	.read_raw	= da311_read_raw,
>> +};
>> +
>> +static int da311_probe(struct i2c_client *client,
>> +			const struct i2c_device_id *id)
>> +{
>> +	int ret;
>> +	struct iio_dev *indio_dev;
>> +	struct da311_data *data;
>> +
>> +	ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
>> +	if (ret != DA311_CHIP_ID)
>> +		return (ret < 0) ? ret : -ENODEV;
>> +
>> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>> +	if (!indio_dev)
>> +		return -ENOMEM;
>> +
>> +	data = iio_priv(indio_dev);
>> +	data->client = client;
>> +	i2c_set_clientdata(client, indio_dev);
>> +
>> +	indio_dev->dev.parent = &client->dev;
>> +	indio_dev->info = &da311_info;
>> +	indio_dev->name = "da311";
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = da311_channels;
>> +	indio_dev->num_channels = ARRAY_SIZE(da311_channels);
>> +
>> +	ret = da311_reset(client);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = da311_enable(client, true);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = iio_device_register(indio_dev);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "device_register failed\n");
>> +		da311_enable(client, false);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static int da311_remove(struct i2c_client *client)
>> +{
>> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +
>> +	iio_device_unregister(indio_dev);
>> +
>> +	return da311_enable(client, false);
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int da311_suspend(struct device *dev)
>> +{
>> +	return da311_enable(to_i2c_client(dev), false);
>> +}
>> +
>> +static int da311_resume(struct device *dev)
>> +{
>> +	return da311_enable(to_i2c_client(dev), true);
>> +}
>> +#endif
> I'd just go with the __maybe_unused option rather than the
> define protection.

Hmm, almost all the drivers I've looked at / know of use
#ifdef here, including the ones under iio/accel.

So I would also prefer to just keep this as is.

Let me know if you want a v3 with anything changed.

Thanks & Regards,

Hans


>> +
>> +static SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);
>> +
>> +static const struct i2c_device_id da311_i2c_id[] = {
>> +	{"da311", 0},
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(i2c, da311_i2c_id);
>> +
>> +static struct i2c_driver da311_driver = {
>> +	.driver = {
>> +		.name = "da311",
>> +		.pm = &da311_pm_ops,
>> +	},
>> +	.probe		= da311_probe,
>> +	.remove		= da311_remove,
>> +	.id_table	= da311_i2c_id,
>> +};
>> +
>> +module_i2c_driver(da311_driver);
>> +
>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>> +MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
>> +MODULE_LICENSE("GPL v2");
>>
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
  2016-09-23 13:51   ` Hans de Goede
@ 2016-09-24 16:46     ` Jonathan Cameron
  0 siblings, 0 replies; 6+ messages in thread
From: Jonathan Cameron @ 2016-09-24 16:46 UTC (permalink / raw)
  To: Hans de Goede, Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald
  Cc: linux-iio

On 23/09/16 14:51, Hans de Goede wrote:
> Hi,
> 
> On 09/22/2016 08:10 PM, Jonathan Cameron wrote:
>> On 22/09/16 14:42, Hans de Goede wrote:
>>> This driver is based on the DA311 Android driver which can be found here:
>>> https://git.matricom.net/Firmware/kernel_amlogic_meson-common/tree/1e70113a5befd07debb68f537156def84c5be57a/drivers/amlogic/input/sensor
>>> the mir3da_* files are the DA311 driver.
>>>
>>> Unfortunately there is no datasheet.
>>>
>> I was crossing my fingers that it was similar to the 312 which does have
>> a datasheet on their website. No such luck.
> 
> Yeah, I also looked at the da312 datasheet, but no luck indeed.
> 
>> Looks good. Couple of really minor comment inline. I'd like this to sit
>> on the mailing list a bit longer. Unfortunately it's just missed the
>> upcoming merge window so we have lots and lots of time :)
>>
>> Jonathan
>>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>> Changes in v2:
>>> -Add proper prefix to patch Subject
>>> -Use i2c_smbus_read_word_data() instead of i2c_smbus_read_i2c_block_data()
>>> ---
>>>  .../devicetree/bindings/i2c/trivial-devices.txt    |   1 +
>>>  drivers/iio/accel/Kconfig                          |  10 +
>>>  drivers/iio/accel/Makefile                         |   1 +
>>>  drivers/iio/accel/da311.c                          | 305 +++++++++++++++++++++
>>>  4 files changed, 317 insertions(+)
>>>  create mode 100644 drivers/iio/accel/da311.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/i2c/trivial-devices.txt b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>> index 21ca02e..8ad9064 100644
>>> --- a/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>> +++ b/Documentation/devicetree/bindings/i2c/trivial-devices.txt
>>> @@ -122,6 +122,7 @@ microchip,mcp4662-502    Microchip 8-bit Dual I2C Digital Potentiometer with NV Mem
>>>  microchip,mcp4662-103    Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (10k)
>>>  microchip,mcp4662-503    Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (50k)
>>>  microchip,mcp4662-104    Microchip 8-bit Dual I2C Digital Potentiometer with NV Memory (100k)
>>> +miramems,da311        MiraMEMS DA311 3-axis 12-bit digital accelerometer
>>>  national,lm63        Temperature sensor with integrated fan control
>>>  national,lm75        I2C TEMP SENSOR
>>>  national,lm80        Serial Interface ACPI-Compatible Microprocessor System Hardware Monitor
>>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>>> index 6236fd5..c94348f 100644
>>> --- a/drivers/iio/accel/Kconfig
>>> +++ b/drivers/iio/accel/Kconfig
>>> @@ -52,6 +52,16 @@ config BMC150_ACCEL_SPI
>>>      tristate
>>>      select REGMAP_SPI
>>>
>>> +config DA311
>>> +    tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
>>> +    depends on I2C
>>> +    help
>>> +      Say yes here to build support for the MiraMEMS DA311 3-axis 12-bit
>>> +      digital accelerometer.
>>> +
>>> +      To compile this driver as a module, choose M here: the
>>> +      module will be called da311.
>>> +
>>>  config DMARD06
>>>      tristate "Domintech DMARD06 Digital Accelerometer Driver"
>>>      depends on OF || COMPILE_TEST
>>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>>> index 9f51559..601ca59 100644
>>> --- a/drivers/iio/accel/Makefile
>>> +++ b/drivers/iio/accel/Makefile
>>> @@ -8,6 +8,7 @@ obj-$(CONFIG_BMA220) += bma220_spi.o
>>>  obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
>>>  obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
>>>  obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
>>> +obj-$(CONFIG_DA311)    += da311.o
>>>  obj-$(CONFIG_DMARD06)    += dmard06.o
>>>  obj-$(CONFIG_DMARD09)    += dmard09.o
>>>  obj-$(CONFIG_DMARD10)    += dmard10.o
>>> diff --git a/drivers/iio/accel/da311.c b/drivers/iio/accel/da311.c
>>> new file mode 100644
>>> index 0000000..8c852f5
>>> --- /dev/null
>>> +++ b/drivers/iio/accel/da311.c
>>> @@ -0,0 +1,305 @@
>>> +/**
>>> + * IIO driver for the MiraMEMS DA311 3-axis accelerometer
>>> + *
>>> + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
>>> + * Copyright (c) 2011-2013 MiraMEMS Sensing Technology Co., Ltd.
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify it
>>> + * under the terms and conditions of the GNU General Public License,
>>> + * version 2, as published by the Free Software Foundation.
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/i2c.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/sysfs.h>
>>> +#include <linux/byteorder/generic.h>
>>> +
>>> +#define DA311_CHIP_ID            0x13
>>> +
>>> +/*
>>> + * Note register addressed go from 0 - 0x3f and then wrap.
>>> + * For some reason there are 2 banks with 0 - 0x3f addresses,
>>> + * rather then a single 0-0x7f bank.
>>> + */
>>> +
>>> +/* Bank 0 regs */
>>> +#define DA311_REG_BANK            0x0000
>>> +#define DA311_REG_LDO_REG        0x0006
>>> +#define DA311_REG_CHIP_ID        0x000f
>>> +#define DA311_REG_TEMP_CFG_REG        0x001f
>>> +#define DA311_REG_CTRL_REG1        0x0020
>>> +#define DA311_REG_CTRL_REG3        0x0022
>>> +#define DA311_REG_CTRL_REG4        0x0023
>>> +#define DA311_REG_CTRL_REG5        0x0024
>>> +#define DA311_REG_CTRL_REG6        0x0025
>>> +#define DA311_REG_STATUS_REG        0x0027
>>> +#define DA311_REG_OUT_X_L        0x0028
>>> +#define DA311_REG_OUT_X_H        0x0029
>>> +#define DA311_REG_OUT_Y_L        0x002a
>>> +#define DA311_REG_OUT_Y_H        0x002b
>>> +#define DA311_REG_OUT_Z_L        0x002c
>>> +#define DA311_REG_OUT_Z_H        0x002d
>>> +#define DA311_REG_INT1_CFG        0x0030
>>> +#define DA311_REG_INT1_SRC        0x0031
>>> +#define DA311_REG_INT1_THS        0x0032
>>> +#define DA311_REG_INT1_DURATION        0x0033
>>> +#define DA311_REG_INT2_CFG        0x0034
>>> +#define DA311_REG_INT2_SRC        0x0035
>>> +#define DA311_REG_INT2_THS        0x0036
>>> +#define DA311_REG_INT2_DURATION        0x0037
>>> +#define DA311_REG_CLICK_CFG        0x0038
>>> +#define DA311_REG_CLICK_SRC        0x0039
>>> +#define DA311_REG_CLICK_THS        0x003a
>>> +#define DA311_REG_TIME_LIMIT        0x003b
>>> +#define DA311_REG_TIME_LATENCY        0x003c
>>> +#define DA311_REG_TIME_WINDOW        0x003d
>>> +
>>> +/* Bank 1 regs */
>>> +#define DA311_REG_SOFT_RESET        0x0105
>>> +#define DA311_REG_OTP_XOFF_L        0x0110
>>> +#define DA311_REG_OTP_XOFF_H        0x0111
>>> +#define DA311_REG_OTP_YOFF_L        0x0112
>>> +#define DA311_REG_OTP_YOFF_H        0x0113
>>> +#define DA311_REG_OTP_ZOFF_L        0x0114
>>> +#define DA311_REG_OTP_ZOFF_H        0x0115
>>> +#define DA311_REG_OTP_XSO        0x0116
>>> +#define DA311_REG_OTP_YSO        0x0117
>>> +#define DA311_REG_OTP_ZSO        0x0118
>>> +#define DA311_REG_OTP_TRIM_OSC        0x011b
>>> +#define DA311_REG_LPF_ABSOLUTE        0x011c
>>> +#define DA311_REG_TEMP_OFF1        0x0127
>>> +#define DA311_REG_TEMP_OFF2        0x0128
>>> +#define DA311_REG_TEMP_OFF3        0x0129
>>> +#define DA311_REG_OTP_TRIM_THERM_H    0x011a
>>> +
>>> +/*
>>> + * a value of + or -1024 corresponds to + or - 1G
>>> + * scale = 1 / 1024 = 0.000976562
>>> + */
>>> +
>>> +static const int da311_nscale = 976562;
>>> +
>>> +#define DA311_CHANNEL(reg, axis) {    \
>>> +    .type = IIO_ACCEL,    \
>>> +    .address = reg,    \
>>> +    .modified = 1,    \
>>> +    .channel2 = IIO_MOD_##axis,    \
>>> +    .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),    \
>>> +    .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),    \
>>> +}
>>> +
>>> +static const struct iio_chan_spec da311_channels[] = {
>>> +    /* | 0x80 comes from the android driver */
>>> +    DA311_CHANNEL(DA311_REG_OUT_X_L | 0x80, X),
>>> +    DA311_CHANNEL(DA311_REG_OUT_Y_L | 0x80, Y),
>>> +    DA311_CHANNEL(DA311_REG_OUT_Z_L | 0x80, Z),
>>> +};
>>> +
>>> +struct da311_data {
>>> +    struct i2c_client *client;
>>> +};
>>> +
>>> +static int da311_register_mask_write(struct i2c_client *client, u16 addr,
>>> +                     u8 mask, u8 data)
>>> +{
>>> +    int ret;
>>> +    u8 tmp_data = 0;
>>> +
>>> +    if (addr & 0xff00) {
>>> +        /* Select bank 1 */
>>> +        ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x01);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +    }
>>> +
>>> +    if (mask != 0xff) {
>>> +        ret = i2c_smbus_read_byte_data(client, addr);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +        tmp_data = ret;
>>> +    }
>>> +
>>> +    tmp_data &= ~mask;
>>> +    tmp_data |= data & mask;
>>> +    ret = i2c_smbus_write_byte_data(client, addr & 0xff, tmp_data);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    if (addr & 0xff00) {
>>> +        /* Back to bank 0 */
>>> +        ret = i2c_smbus_write_byte_data(client, DA311_REG_BANK, 0x00);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +/* Init sequence taken from the android driver */
>>> +static int da311_reset(struct i2c_client *client)
>>> +{
>>> +    const struct {
>>> +        u16 addr;
>>> +        u8 mask;
>>> +        u8 data;
>>> +    } init_data[] = {
>>> +        { DA311_REG_TEMP_CFG_REG,       0xff,   0x08 },
>>> +        { DA311_REG_CTRL_REG5,          0xff,   0x80 },
>>> +        { DA311_REG_CTRL_REG4,          0x30,   0x00 },
>>> +        { DA311_REG_CTRL_REG1,          0xff,   0x6f },
>>> +        { DA311_REG_TEMP_CFG_REG,       0xff,   0x88 },
>>> +        { DA311_REG_LDO_REG,            0xff,   0x02 },
>>> +        { DA311_REG_OTP_TRIM_OSC,       0xff,   0x27 },
>>> +        { DA311_REG_LPF_ABSOLUTE,       0xff,   0x30 },
>>> +        { DA311_REG_TEMP_OFF1,          0xff,   0x3f },
>>> +        { DA311_REG_TEMP_OFF2,          0xff,   0xff },
>>> +        { DA311_REG_TEMP_OFF3,          0xff,   0x0f },
>> Nice ;)  Not much we can do about this without a datasheet. Ah well.
> 
> Yes, ah well indeed.
> 
>>> +    };
>>> +    int i, ret;
>>> +
>>> +    /* Reset */
>>> +    ret = da311_register_mask_write(client, DA311_REG_SOFT_RESET,
>>> +                    0xff, 0xaa);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    for (i = 0; i < ARRAY_SIZE(init_data); i++) {
>>> +        ret = da311_register_mask_write(client,
>>> +                        init_data[i].addr,
>>> +                        init_data[i].mask,
>>> +                        init_data[i].data);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int da311_enable(struct i2c_client *client, bool enable)
>>> +{
>>> +    u8 data = enable ? 0x00 : 0x20;
>> This feels ever so slightly like a magic number that ought to be
>> a define rather than inline.  Probably using BIT(5) to define it.
>> I guess this would be more obvious if we had a datasheet to tell us
>> what to call it etc.
> 
> The problem is we've no clue what to call the define, so I would
> prefer to just keep this as is.
> 
>>> +
>>> +    return da311_register_mask_write(client, DA311_REG_TEMP_CFG_REG,
>>> +                     0x20, data);
>>> +}
>>> +
>>> +static int da311_read_raw(struct iio_dev *indio_dev,
>>> +                struct iio_chan_spec const *chan,
>>> +                int *val, int *val2, long mask)
>>> +{
>>> +    struct da311_data *data = iio_priv(indio_dev);
>>> +    int ret;
>>> +
>>> +    switch (mask) {
>>> +    case IIO_CHAN_INFO_RAW:
>>> +        ret = i2c_smbus_read_word_data(data->client, chan->address);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +        /*
>>> +         * Values are 12 bits, stored as 16 bits with the 4
>>> +         * least significant bits always 0.
>>> +         */
>>> +        *val = ((short)le16_to_cpu(ret)) >> 4;
>>> +        return IIO_VAL_INT;
>>> +    case IIO_CHAN_INFO_SCALE:
>>> +        *val = 0;
>>> +        *val2 = da311_nscale;
>>> +        return IIO_VAL_INT_PLUS_NANO;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +}
>>> +
>>> +static const struct iio_info da311_info = {
>>> +    .driver_module    = THIS_MODULE,
>>> +    .read_raw    = da311_read_raw,
>>> +};
>>> +
>>> +static int da311_probe(struct i2c_client *client,
>>> +            const struct i2c_device_id *id)
>>> +{
>>> +    int ret;
>>> +    struct iio_dev *indio_dev;
>>> +    struct da311_data *data;
>>> +
>>> +    ret = i2c_smbus_read_byte_data(client, DA311_REG_CHIP_ID);
>>> +    if (ret != DA311_CHIP_ID)
>>> +        return (ret < 0) ? ret : -ENODEV;
>>> +
>>> +    indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
>>> +    if (!indio_dev)
>>> +        return -ENOMEM;
>>> +
>>> +    data = iio_priv(indio_dev);
>>> +    data->client = client;
>>> +    i2c_set_clientdata(client, indio_dev);
>>> +
>>> +    indio_dev->dev.parent = &client->dev;
>>> +    indio_dev->info = &da311_info;
>>> +    indio_dev->name = "da311";
>>> +    indio_dev->modes = INDIO_DIRECT_MODE;
>>> +    indio_dev->channels = da311_channels;
>>> +    indio_dev->num_channels = ARRAY_SIZE(da311_channels);
>>> +
>>> +    ret = da311_reset(client);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    ret = da311_enable(client, true);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    ret = iio_device_register(indio_dev);
>>> +    if (ret < 0) {
>>> +        dev_err(&client->dev, "device_register failed\n");
>>> +        da311_enable(client, false);
>>> +    }
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static int da311_remove(struct i2c_client *client)
>>> +{
>>> +    struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>> +
>>> +    iio_device_unregister(indio_dev);
>>> +
>>> +    return da311_enable(client, false);
>>> +}
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int da311_suspend(struct device *dev)
>>> +{
>>> +    return da311_enable(to_i2c_client(dev), false);
>>> +}
>>> +
>>> +static int da311_resume(struct device *dev)
>>> +{
>>> +    return da311_enable(to_i2c_client(dev), true);
>>> +}
>>> +#endif
>> I'd just go with the __maybe_unused option rather than the
>> define protection.
> 
> Hmm, almost all the drivers I've looked at / know of use
> #ifdef here, including the ones under iio/accel.
> 
> So I would also prefer to just keep this as is.
> 
> Let me know if you want a v3 with anything changed.
It's becoming a more common solution to do it with the unused
route as these functions tend to be tiny and the ifdefs
are ugly. 

I don't care enough though to warrant a change.

Applied to the togreg branch of iio.git - initially pushed out
as testing for the autobuilders to play with it.

Thanks,

Jonathan

> 
> Thanks & Regards,
> 
> Hans
> 
> 
>>> +
>>> +static SIMPLE_DEV_PM_OPS(da311_pm_ops, da311_suspend, da311_resume);
>>> +
>>> +static const struct i2c_device_id da311_i2c_id[] = {
>>> +    {"da311", 0},
>>> +    {}
>>> +};
>>> +MODULE_DEVICE_TABLE(i2c, da311_i2c_id);
>>> +
>>> +static struct i2c_driver da311_driver = {
>>> +    .driver = {
>>> +        .name = "da311",
>>> +        .pm = &da311_pm_ops,
>>> +    },
>>> +    .probe        = da311_probe,
>>> +    .remove        = da311_remove,
>>> +    .id_table    = da311_i2c_id,
>>> +};
>>> +
>>> +module_i2c_driver(da311_driver);
>>> +
>>> +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
>>> +MODULE_DESCRIPTION("MiraMEMS DA311 3-Axis Accelerometer driver");
>>> +MODULE_LICENSE("GPL v2");
>>>
>>
> -- 
> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
  2016-09-22 13:42 [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer Hans de Goede
  2016-09-22 17:10 ` Jonathan Cameron
@ 2016-09-25 15:11 ` Lars-Peter Clausen
  2016-09-25 16:44   ` Jonathan Cameron
  1 sibling, 1 reply; 6+ messages in thread
From: Lars-Peter Clausen @ 2016-09-25 15:11 UTC (permalink / raw)
  To: Hans de Goede, Jonathan Cameron, Hartmut Knaack, Peter Meerwald; +Cc: linux-iio

On 09/22/2016 03:42 PM, Hans de Goede wrote:
[...]
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
> +		if (ret < 0)
> +			return ret;
> +		/*
> +		 * Values are 12 bits, stored as 16 bits with the 4
> +		 * least significant bits always 0.
> +		 */
> +		*val = ((short)le16_to_cpu(ret)) >> 4;

I think the le16_to_cpu() is a leftover from the switch away from
i2c_smbus_read_i2c_block_data(). i2c_smbus_read_word_data() already returns
CPU endianess data. On a BE system le16_to_cpu() swaps the lower and upper
bytes on a BE system. So you'd get the wrong value in that case.

> +		return IIO_VAL_INT;


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer
  2016-09-25 15:11 ` Lars-Peter Clausen
@ 2016-09-25 16:44   ` Jonathan Cameron
  0 siblings, 0 replies; 6+ messages in thread
From: Jonathan Cameron @ 2016-09-25 16:44 UTC (permalink / raw)
  To: Lars-Peter Clausen, Hans de Goede, Hartmut Knaack, Peter Meerwald
  Cc: linux-iio

On 25/09/16 16:11, Lars-Peter Clausen wrote:
> On 09/22/2016 03:42 PM, Hans de Goede wrote:
> [...]
>> +	switch (mask) {
>> +	case IIO_CHAN_INFO_RAW:
>> +		ret = i2c_smbus_read_word_data(data->client, chan->address);
>> +		if (ret < 0)
>> +			return ret;
>> +		/*
>> +		 * Values are 12 bits, stored as 16 bits with the 4
>> +		 * least significant bits always 0.
>> +		 */
>> +		*val = ((short)le16_to_cpu(ret)) >> 4;
> 
> I think the le16_to_cpu() is a leftover from the switch away from
> i2c_smbus_read_i2c_block_data(). i2c_smbus_read_word_data() already returns
> CPU endianess data. On a BE system le16_to_cpu() swaps the lower and upper
> bytes on a BE system. So you'd get the wrong value in that case.
Backed out.  Please check the scale value as well for v3.

Thanks,

Jonathan
> 
>> +		return IIO_VAL_INT;
> 
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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-09-25 16:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-09-22 13:42 [PATCH v2] iio: accel: Add driver for the MiraMEMS DA311 3-axis 12-bit digital accelerometer Hans de Goede
2016-09-22 17:10 ` Jonathan Cameron
2016-09-23 13:51   ` Hans de Goede
2016-09-24 16:46     ` Jonathan Cameron
2016-09-25 15:11 ` Lars-Peter Clausen
2016-09-25 16:44   ` Jonathan Cameron

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