Message-ID: <4D89D719.3090107@cam.ac.uk>
Date: Wed, 23 Mar 2011 11:18:49 +0000
From: Jonathan Cameron <jic23@cam.ac.uk>
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To: cliff.cai@analog.com
CC: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        drivers@analog.com, device-drivers-devel@blackfin.uclinux.org
Subject: Re: [PATCH 2/3 RESEND v3] IIO driver for Analog Devices Digital Output
 Gyroscope ADXRS450
References: <1300871727-32239-1-git-send-email-cliff.cai@analog.com> <1300871727-32239-2-git-send-email-cliff.cai@analog.com>
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On 03/23/11 09:15, cliff.cai@analog.com wrote:
> From: Cliff Cai <cliff.cai@analog.com>
> 
> Change v3:v2;
> 	clean up code according to Jonathan' comments.

Couple of really trivial nitpicks inline. Might as well fix them up before
sending to Greg.

Nice driver, thanks,
> 
> Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/gyro/Kconfig         |   10 +
>  drivers/staging/iio/gyro/Makefile        |    3 +
>  drivers/staging/iio/gyro/adxrs450.h      |   58 ++++
>  drivers/staging/iio/gyro/adxrs450_core.c |  450 ++++++++++++++++++++++++++++++
>  4 files changed, 521 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/staging/iio/gyro/adxrs450.h
>  create mode 100644 drivers/staging/iio/gyro/adxrs450_core.c
> 
> diff --git a/drivers/staging/iio/gyro/Kconfig b/drivers/staging/iio/gyro/Kconfig
> index 8b78fa0..ae2e7d3 100644
> --- a/drivers/staging/iio/gyro/Kconfig
> +++ b/drivers/staging/iio/gyro/Kconfig
> @@ -35,3 +35,13 @@ config ADIS16260
>  
>  	  This driver can also be built as a module.  If so, the module
>  	  will be called adis16260.
> +
> +config ADXRS450
> +	tristate "Analog Devices ADXRS450 Digital Output Gyroscope SPI driver"
> +	depends on SPI
> +	help
> +	  Say yes here to build support for Analog Devices ADXRS450 programmable
> +	  digital output gyroscope.
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called adxrs450.
> diff --git a/drivers/staging/iio/gyro/Makefile b/drivers/staging/iio/gyro/Makefile
> index 2764c15..2212240 100644
> --- a/drivers/staging/iio/gyro/Makefile
> +++ b/drivers/staging/iio/gyro/Makefile
> @@ -17,3 +17,6 @@ obj-$(CONFIG_ADIS16260) += adis16260.o
>  
>  adis16251-y             := adis16251_core.o
>  obj-$(CONFIG_ADIS16251) += adis16251.o
> +
> +adxrs450-y             := adxrs450_core.o
> +obj-$(CONFIG_ADXRS450) += adxrs450.o
> diff --git a/drivers/staging/iio/gyro/adxrs450.h b/drivers/staging/iio/gyro/adxrs450.h
> new file mode 100644
> index 0000000..c92f694
> --- /dev/null
> +++ b/drivers/staging/iio/gyro/adxrs450.h
> @@ -0,0 +1,58 @@
> +#ifndef SPI_ADXRS450_H_
> +#define SPI_ADXRS450_H_
> +
> +#define ADXRS450_STARTUP_DELAY	50 /* ms */
> +
> +/* The MSB for the spi commands */
> +#define ADXRS450_SENSOR_DATA    0x20
> +#define ADXRS450_WRITE_DATA	0x40
> +#define ADXRS450_READ_DATA	0x80
> +
> +#define ADXRS450_RATE1	0x00	/* Rate Registers */
> +#define ADXRS450_TEMP1	0x02	/* Temperature Registers */
> +#define ADXRS450_LOCST1	0x04	/* Low CST Memory Registers */
> +#define ADXRS450_HICST1	0x06	/* High CST Memory Registers */
> +#define ADXRS450_QUAD1	0x08	/* Quad Memory Registers */
> +#define ADXRS450_FAULT1	0x0A	/* Fault Registers */
> +#define ADXRS450_PID1	0x0C	/* Part ID Register 1 */
> +#define ADXRS450_SNH	0x0E	/* Serial Number Registers, 4 bytes */
> +#define ADXRS450_SNL	0x10
> +#define ADXRS450_DNC1	0x12	/* Dynamic Null Correction Registers */
> +/* Check bits */
> +#define ADXRS450_P	0x01
> +#define ADXRS450_CHK	0x02
> +#define ADXRS450_CST	0x04
> +#define ADXRS450_PWR	0x08
> +#define ADXRS450_POR	0x10
> +#define ADXRS450_NVM	0x20
> +#define ADXRS450_Q	0x40
> +#define ADXRS450_PLL	0x80
> +#define ADXRS450_UV	0x100
> +#define ADXRS450_OV	0x200
> +#define ADXRS450_AMP	0x400
> +#define ADXRS450_FAIL	0x800
> +
> +#define ADXRS450_WRERR_MASK	(0x7 << 29)
> +
> +#define ADXRS450_MAX_RX 4
> +#define ADXRS450_MAX_TX 4
> +
> +#define ADXRS450_GET_ST(a)	((a >> 26) & 0x3)
> +
> +/**
> + * struct adxrs450_state - device instance specific data
> + * @us:			actual spi_device
> + * @indio_dev:		industrial I/O device structure
> + * @tx:			transmit buffer
> + * @rx:			recieve buffer
> + * @buf_lock:		mutex to protect tx and rx
> + **/
> +struct adxrs450_state {
> +	struct spi_device		*us;
> +	struct iio_dev			*indio_dev;
> +	u8				*tx;
> +	u8				*rx;
> +	struct mutex			buf_lock;
> +};
> +
> +#endif /* SPI_ADXRS450_H_ */
> diff --git a/drivers/staging/iio/gyro/adxrs450_core.c b/drivers/staging/iio/gyro/adxrs450_core.c
> new file mode 100644
> index 0000000..263230d
> --- /dev/null
> +++ b/drivers/staging/iio/gyro/adxrs450_core.c
> @@ -0,0 +1,450 @@
> +/*
> + * ADXRS450 Digital Output Gyroscope Driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/gpio.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/spi/spi.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +#include <linux/list.h>
> +
> +#include "../iio.h"
> +#include "../sysfs.h"
> +#include "gyro.h"
> +#include "../adc/adc.h"
> +
> +#include "adxrs450.h"
> +
> +/**
> + * adxrs450_spi_read_reg_16() - read 2 bytes from a register pair
> + * @dev: device associated with child of actual iio_dev
> + * @reg_address: the address of the lower of the two registers,which should be an even address,
> + * Second register's address is reg_address + 1.
> + * @val: somewhere to pass back the value read
> + **/
> +static int adxrs450_spi_read_reg_16(struct device *dev,
> +		u8 reg_address,
> +		u16 *val)
> +{
> +	struct spi_message msg;
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct adxrs450_state *st = iio_dev_get_devdata(indio_dev);
> +	int ret;
> +	struct spi_transfer xfers = {
> +		.tx_buf = st->tx,
> +		.rx_buf = st->rx,
> +		.bits_per_word = 8,
> +		.len = 4,
> +	};
> +	/* Needs to send the command twice to get the wanted value */
> +	mutex_lock(&st->buf_lock);
> +	st->tx[0] = ADXRS450_READ_DATA | reg_address >> 7;
> +	st->tx[1] = reg_address << 1;
> +	st->tx[2] = 0;
> +	st->tx[3] = 0;
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret) {
> +		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
> +				reg_address);
> +		goto error_ret;
> +	}
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret) {
> +		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",
> +				reg_address);
> +		goto error_ret;
> +	}
> +
> +	*val = (st->rx[1] & 0x1f) << 11 | st->rx[2] << 3 | (st->rx[3] & 0xe0) >> 5;
> +
> +error_ret:
> +	mutex_unlock(&st->buf_lock);
> +	return ret;
> +}
> +
> +/**
> + * adxrs450_spi_write_reg_16() - write 2 bytes data to a register pair
> + * @dev: device associated with child of actual actual iio_dev
> + * @reg_address: the address of the lower of the two registers,which should be an even address,
> + * Second register's address is reg_address + 1.
> + * @val: value to be written.
> + **/
> +static int adxrs450_spi_write_reg_16(struct device *dev,
> +		u8 reg_address,
> +		u16 val)
> +{
> +	struct spi_message msg;
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct adxrs450_state *st = iio_dev_get_devdata(indio_dev);
> +	int ret;
> +	struct spi_transfer xfers = {
> +		.tx_buf = st->tx,
> +		.rx_buf = st->rx,
> +		.bits_per_word = 8,
> +		.len = 4,
> +	};
> +
> +	mutex_lock(&st->buf_lock);
> +	st->tx[0] = ADXRS450_WRITE_DATA | reg_address >> 7;
> +	st->tx[1] = reg_address << 1 | val >> 15;
> +	st->tx[2] = val >> 7;
> +	st->tx[3] = val << 1;
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret)
> +		dev_err(&st->us->dev, "problem while writing 16 bit register 0x%02x\n",
> +				reg_address);
> +	mutex_unlock(&st->buf_lock);
> +	return ret;
> +}
> +
> +/**
> + * adxrs450_spi_sensor_data() - read 2 bytes sensor data
> + * @dev: device associated with child of actual iio_dev
> + * @val: somewhere to pass back the value read
> + **/
> +static int adxrs450_spi_sensor_data(struct device *dev, u16 *val)
> +{
> +	struct spi_message msg;
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct adxrs450_state *st = iio_dev_get_devdata(indio_dev);
> +	int ret;
> +	struct spi_transfer xfers = {
> +		.tx_buf = st->tx,
> +		.rx_buf = st->rx,
> +		.bits_per_word = 8,
> +		.len = 4,
> +	};
> +
> +	mutex_lock(&st->buf_lock);
> +	st->tx[0] = ADXRS450_SENSOR_DATA;
> +	st->tx[1] = 0;
> +	st->tx[2] = 0;
> +	st->tx[3] = 0;
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret) {
> +		dev_err(&st->us->dev, "Problem while reading sensor data\n");
> +		goto error_ret;
> +	}
> +
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret) {
> +		dev_err(&st->us->dev, "Problem while reading sensor data\n");
> +		goto error_ret;
> +	}
> +
> +	*val = (st->rx[0] & 0x03) << 14 | st->rx[1] << 6 | (st->rx[2] & 0xfc) >> 2;
> +error_ret:
> +	mutex_unlock(&st->buf_lock);
> +	return ret;
> +}
> +
> +/**
> + * adxrs450_spi_initial() - use for initializing procedure.
> + * @st: device instance specific data
> + * @val: somewhere to pass back the value read
> + **/
> +static int adxrs450_spi_initial(struct adxrs450_state *st,
> +		u32 *val, char chk)
> +{
> +	struct spi_message msg;
> +	int ret;
> +	struct spi_transfer xfers = {
> +		.tx_buf = st->tx,
> +		.rx_buf = st->rx,
> +		.bits_per_word = 8,
> +		.len = 4,
> +	};
> +
> +	mutex_lock(&st->buf_lock);
> +	st->tx[0] = ADXRS450_SENSOR_DATA;
> +	st->tx[1] = 0;
> +	st->tx[2] = 0;
> +	st->tx[3] = 0;
> +	if (chk)
> +		st->tx[3] |= (ADXRS450_CHK | ADXRS450_P);
> +	spi_message_init(&msg);
> +	spi_message_add_tail(&xfers, &msg);
> +	ret = spi_sync(st->us, &msg);
> +	if (ret) {
> +		dev_err(&st->us->dev, "Problem while reading initializing data\n");
> +		goto error_ret;
> +	}
> +
> +	*val = be32_to_cpu(*(u32 *)st->rx);
> +
> +error_ret:
> +	mutex_unlock(&st->buf_lock);
> +	return ret;
> +}
> +
> +static ssize_t adxrs450_read_temp(struct device *dev,
> +		struct device_attribute *attr,
> +		char *buf)
> +{
> +	int ret, len;
> +	u16 t;
> +	ret = adxrs450_spi_read_reg_16(dev,
> +			ADXRS450_TEMP1,
> +			&t);
> +	if (ret)
> +		return ret;
> +	len = sprintf(buf, "%d\n", t);
Combine lines.
> +	return len;
> +}
> +
> +static ssize_t adxrs450_read_quad(struct device *dev,
> +		struct device_attribute *attr,
> +		char *buf)
> +{
> +	int ret, len;
> +	u16 t;
> +	ret = adxrs450_spi_read_reg_16(dev,
> +			ADXRS450_QUAD1,
> +			&t);
> +	if (ret)
> +		return ret;
> +	len = sprintf(buf, "%d\n", t);
> +	return len;
Combine previous two lines and get rid of len.
> +}
> +
> +static ssize_t adxrs450_write_dnc(struct device *dev,
> +		struct device_attribute *attr,
> +		const char *buf,
> +		size_t len)
> +{
> +	int ret;
> +	long val;
> +
> +	ret = strict_strtol(buf, 10, &val);
> +	if (ret)
> +		goto error_ret;
> +	ret = adxrs450_spi_write_reg_16(dev,
> +			ADXRS450_DNC1,
> +			val);
> +error_ret:
> +	return ret ? ret : len;
> +}
> +
> +static ssize_t adxrs450_read_sensor_data(struct device *dev,
> +		struct device_attribute *attr,
> +		char *buf)
> +{
> +	int ret, len = 0;
> +	u16 t;
> +
> +	ret = adxrs450_spi_sensor_data(dev, &t);
> +	if (ret)
> +		return ret;
> +
> +	len = sprintf(buf, "%d\n", t);
> +	return len;
Could combine previous two lines and get rid of assignment of len = 0
(which wasn't needed anyway!)
> +}
> +
> +/* Recommended Startup Sequence by spec */
> +static int adxrs450_initial_setup(struct adxrs450_state *st)
> +{
> +	u32 t;
> +	u16 data;
> +	int ret;
> +	struct device *dev = &st->indio_dev->dev;
> +
> +	msleep(ADXRS450_STARTUP_DELAY*2);
> +	ret = adxrs450_spi_initial(st, &t, 1);
> +	if (ret)
> +		return ret;
> +	if (t != 0x01) {
> +		dev_err(&st->us->dev, "The initial response is not correct!\n");
> +		return -ENODEV;
> +
> +	}
> +
> +	msleep(ADXRS450_STARTUP_DELAY);
> +	ret = adxrs450_spi_initial(st, &t, 0);
> +	if (ret)
> +		return ret;
> +
> +	msleep(ADXRS450_STARTUP_DELAY);
> +	ret = adxrs450_spi_initial(st, &t, 0);
> +	if (ret)
> +		return ret;
> +	if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) {
> +		dev_err(&st->us->dev, "The second response is not correct!\n");
> +		return -EIO;
> +
> +	}
> +	ret = adxrs450_spi_initial(st, &t, 0);
> +	if (ret)
> +		return ret;
> +	if (((t & 0xff) | 0x01) != 0xff || ADXRS450_GET_ST(t) != 2) {
> +		dev_err(&st->us->dev, "The third response is not correct!\n");
> +		return -EIO;
> +
> +	}
> +	ret = adxrs450_spi_read_reg_16(dev, ADXRS450_FAULT1, &data);
> +	if (ret)
> +		return ret;
> +	if (data & 0x0fff) {
> +		dev_err(&st->us->dev, "The device is not in normal status!\n");
> +		return -EINVAL;
> +	}
> +	ret = adxrs450_spi_read_reg_16(dev, ADXRS450_PID1, &data);
> +	if (ret)
> +		return ret;
> +	dev_info(&st->us->dev, "The Part ID is 0x%x\n", data);
> +
> +	ret = adxrs450_spi_read_reg_16(dev, ADXRS450_SNL, &data);
> +	if (ret)
> +		return ret;
> +	t = data;
> +	ret = adxrs450_spi_read_reg_16(dev, ADXRS450_SNH, &data);
> +	if (ret)
> +		return ret;
> +	t |= data << 16;
> +	dev_info(&st->us->dev, "The Serial Number is 0x%x\n", t);
> +
> +	return 0;
> +}
> +
> +static IIO_DEV_ATTR_GYRO_Z(adxrs450_read_sensor_data, 0);
> +static IIO_DEV_ATTR_TEMP_RAW(adxrs450_read_temp);
> +static IIO_DEV_ATTR_GYRO_Z_QUADRATURE_CORRECTION(adxrs450_read_quad, 0);
> +static IIO_DEV_ATTR_GYRO_Z_CALIBBIAS(S_IWUSR,
> +		NULL, adxrs450_write_dnc, 0);
> +static IIO_CONST_ATTR(name, "adxrs450");
> +
> +static struct attribute *adxrs450_attributes[] = {
> +	&iio_dev_attr_gyro_z_raw.dev_attr.attr,
> +	&iio_dev_attr_temp_raw.dev_attr.attr,
> +	&iio_dev_attr_gyro_z_quadrature_correction_raw.dev_attr.attr,
> +	&iio_dev_attr_gyro_z_calibbias.dev_attr.attr,
> +	&iio_const_attr_name.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group adxrs450_attribute_group = {
> +	.attrs = adxrs450_attributes,
> +};
> +
> +static int __devinit adxrs450_probe(struct spi_device *spi)
> +{
> +	int ret, regdone = 0;
> +	struct adxrs450_state *st = kzalloc(sizeof *st, GFP_KERNEL);
> +	if (!st) {
> +		ret =  -ENOMEM;
> +		goto error_ret;
> +	}
> +	/* This is only used for removal purposes */
> +	spi_set_drvdata(spi, st);
> +
> +	/* Allocate the comms buffers */
> +	st->rx = kzalloc(sizeof(*st->rx)*ADXRS450_MAX_RX, GFP_KERNEL);
> +	if (st->rx == NULL) {
> +		ret = -ENOMEM;
> +		goto error_free_st;
> +	}
> +	st->tx = kzalloc(sizeof(*st->tx)*ADXRS450_MAX_TX, GFP_KERNEL);
> +	if (st->tx == NULL) {
> +		ret = -ENOMEM;
> +		goto error_free_rx;
> +	}
> +	st->us = spi;
> +	mutex_init(&st->buf_lock);
> +	/* setup the industrialio driver allocated elements */
> +	st->indio_dev = iio_allocate_device();
> +	if (st->indio_dev == NULL) {
> +		ret = -ENOMEM;
> +		goto error_free_tx;
> +	}
> +
> +	st->indio_dev->dev.parent = &spi->dev;
> +	st->indio_dev->attrs = &adxrs450_attribute_group;
> +	st->indio_dev->dev_data = (void *)(st);
> +	st->indio_dev->driver_module = THIS_MODULE;
> +	st->indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = iio_device_register(st->indio_dev);
> +	if (ret)
> +		goto error_free_dev;
> +	regdone = 1;
> +
> +	/* Get the device into a sane initial state */
> +	ret = adxrs450_initial_setup(st);
> +	if (ret)
> +		goto error_initial;
> +	return 0;
> +
> +error_initial:
> +error_free_dev:
> +	if (regdone)
> +		iio_device_unregister(st->indio_dev);
> +	else
> +		iio_free_device(st->indio_dev);
> +error_free_tx:
> +	kfree(st->tx);
> +error_free_rx:
> +	kfree(st->rx);
> +error_free_st:
> +	kfree(st);
> +error_ret:
> +	return ret;
> +}
> +
> +/* fixme, confirm ordering in this function */
Err? So is it.  (have a feeling this is a cut and
pasted comment from somewhere else ;)
> +static int adxrs450_remove(struct spi_device *spi)
> +{
> +	struct adxrs450_state *st = spi_get_drvdata(spi);
> +
> +	iio_device_unregister(st->indio_dev);
> +	kfree(st->tx);
> +	kfree(st->rx);
> +	kfree(st);
> +
> +	return 0;
> +}
...

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