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Commit 447aef1a authored by Ben Dooks's avatar Ben Dooks Committed by Linus Torvalds
Browse files

SPI: tle620x power switch driver 



Add support for the Infineon TLE62x0 series of low-side driver chips, such
as the TLE6220 or TLE6230.  These can be viewed as output GPIOs specialized
for power switching applications.  The driver provides a userspace
interface to those GPIOs, and to the switch status they provide.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent da0abc27

drivers/spi/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -198,6 +198,15 @@ config SPI_SPIDEV 
	  Note that this application programming interface is EXPERIMENTAL

	  and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.



config SPI_TLE62X0

	tristate "Infineon TLE62X0 (for power switching)"

	depends on SPI_MASTER && SYSFS

	help

	  SPI driver for Infineon TLE62X0 series line driver chips,

	  such as the TLE6220, TLE6230 and TLE6240.  This provides a

	  sysfs interface, with each line presented as a kind of GPIO

	  exposing both switch control and diagnostic feedback.



#

# Add new SPI protocol masters in alphabetical order above this line

#

drivers/spi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx.o 
# SPI protocol drivers (device/link on bus)

obj-$(CONFIG_SPI_AT25)		+= at25.o

obj-$(CONFIG_SPI_SPIDEV)	+= spidev.o

obj-$(CONFIG_SPI_TLE62X0)	+= tle62x0.o

# 	... add above this line ...



# SPI slave controller drivers (upstream link)

drivers/spi/tle62x0.c

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Original line number Diff line number Diff line 
/*

 * tle62x0.c -- support Infineon TLE62x0 driver chips

 *

 * Copyright (c) 2007 Simtec Electronics

 *	Ben Dooks, <ben@simtec.co.uk>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */



#include <linux/device.h>

#include <linux/kernel.h>



#include <linux/spi/spi.h>

#include <linux/spi/tle62x0.h>





#define CMD_READ	0x00

#define CMD_SET		0xff



#define DIAG_NORMAL	0x03

#define DIAG_OVERLOAD	0x02

#define DIAG_OPEN	0x01

#define DIAG_SHORTGND	0x00



struct tle62x0_state {

	struct spi_device	*us;

	struct mutex		lock;

	unsigned int		nr_gpio;

	unsigned int		gpio_state;



	unsigned char		tx_buff[4];

	unsigned char		rx_buff[4];

};



static int to_gpio_num(struct device_attribute *attr);



static inline int tle62x0_write(struct tle62x0_state *st)

{

	unsigned char *buff = st->tx_buff;

	unsigned int gpio_state = st->gpio_state;



	buff[0] = CMD_SET;



	if (st->nr_gpio == 16) {

		buff[1] = gpio_state >> 8;

		buff[2] = gpio_state;

	} else {

		buff[1] = gpio_state;

	}



	dev_dbg(&st->us->dev, "buff %02x,%02x,%02x\n",

		buff[0], buff[1], buff[2]);



	return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);

}



static inline int tle62x0_read(struct tle62x0_state *st)

{

	unsigned char *txbuff = st->tx_buff;

	struct spi_transfer xfer = {

		.tx_buf		= txbuff,

		.rx_buf		= st->rx_buff,

		.len		= (st->nr_gpio * 2) / 8,

	};

	struct spi_message msg;



	txbuff[0] = CMD_READ;

	txbuff[1] = 0x00;

	txbuff[2] = 0x00;

	txbuff[3] = 0x00;



	spi_message_init(&msg);

	spi_message_add_tail(&xfer, &msg);



	return spi_sync(st->us, &msg);

}



static unsigned char *decode_fault(unsigned int fault_code)

{

	fault_code &= 3;



	switch (fault_code) {

	case DIAG_NORMAL:

		return "N";

	case DIAG_OVERLOAD:

		return "V";

	case DIAG_OPEN:

		return "O";

	case DIAG_SHORTGND:

		return "G";

	}



	return "?";

}



static ssize_t tle62x0_status_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct tle62x0_state *st = dev_get_drvdata(dev);

	char *bp = buf;

	unsigned char *buff = st->rx_buff;

	unsigned long fault = 0;

	int ptr;

	int ret;



	mutex_lock(&st->lock);

	ret = tle62x0_read(st);



	dev_dbg(dev, "tle62x0_read() returned %d\n", ret);



	for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {

		fault <<= 8;

		fault  |= ((unsigned long)buff[ptr]);



		dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);

	}



	for (ptr = 0; ptr < st->nr_gpio; ptr++) {

		bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));

	}



	*bp++ = '\n';



	mutex_unlock(&st->lock);

	return bp - buf;

}



static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);



static ssize_t tle62x0_gpio_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct tle62x0_state *st = dev_get_drvdata(dev);

	int gpio_num = to_gpio_num(attr);

	int value;



	mutex_lock(&st->lock);

	value = (st->gpio_state >> gpio_num) & 1;

	mutex_unlock(&st->lock);



	return snprintf(buf, PAGE_SIZE, "%d", value);

}



static ssize_t tle62x0_gpio_store(struct device *dev,

		struct device_attribute *attr,

		const char *buf, size_t len)

{

	struct tle62x0_state *st = dev_get_drvdata(dev);

	int gpio_num = to_gpio_num(attr);

	unsigned long val;

	char *endp;



	val = simple_strtoul(buf, &endp, 0);

	if (buf == endp)

		return -EINVAL;



	dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);



	mutex_lock(&st->lock);



	if (val)

		st->gpio_state |= 1 << gpio_num;

	else

		st->gpio_state &= ~(1 << gpio_num);



	tle62x0_write(st);

	mutex_unlock(&st->lock);



	return len;

}



static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);

static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,

		tle62x0_gpio_show, tle62x0_gpio_store);



static struct device_attribute *gpio_attrs[] = {

	[0]		= &dev_attr_gpio1,

	[1]		= &dev_attr_gpio2,

	[2]		= &dev_attr_gpio3,

	[3]		= &dev_attr_gpio4,

	[4]		= &dev_attr_gpio5,

	[5]		= &dev_attr_gpio6,

	[6]		= &dev_attr_gpio7,

	[7]		= &dev_attr_gpio8,

	[8]		= &dev_attr_gpio9,

	[9]		= &dev_attr_gpio10,

	[10]		= &dev_attr_gpio11,

	[11]		= &dev_attr_gpio12,

	[12]		= &dev_attr_gpio13,

	[13]		= &dev_attr_gpio14,

	[14]		= &dev_attr_gpio15,

	[15]		= &dev_attr_gpio16

};



static int to_gpio_num(struct device_attribute *attr)

{

	int ptr;



	for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {

		if (gpio_attrs[ptr] == attr)

			return ptr;

	}



	return -1;

}



static int __devinit tle62x0_probe(struct spi_device *spi)

{

	struct tle62x0_state *st;

	struct tle62x0_pdata *pdata;

	int ptr;

	int ret;



	pdata = spi->dev.platform_data;

	if (pdata == NULL) {

		dev_err(&spi->dev, "no device data specified\n");

		return -EINVAL;

	}



	st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);

	if (st == NULL) {

		dev_err(&spi->dev, "no memory for device state\n");

		return -ENOMEM;

	}



	st->us = spi;

	st->nr_gpio = pdata->gpio_count;

	st->gpio_state = pdata->init_state;



	mutex_init(&st->lock);



	ret = device_create_file(&spi->dev, &dev_attr_status_show);

	if (ret) {

		dev_err(&spi->dev, "cannot create status attribute\n");

		goto err_status;

	}



	for (ptr = 0; ptr < pdata->gpio_count; ptr++) {

		ret = device_create_file(&spi->dev, gpio_attrs[ptr]);

		if (ret) {

			dev_err(&spi->dev, "cannot create gpio attribute\n");

			goto err_gpios;

		}

	}



	/* tle62x0_write(st); */

	spi_set_drvdata(spi, st);

	return 0;



 err_gpios:

	for (; ptr > 0; ptr--)

		device_remove_file(&spi->dev, gpio_attrs[ptr]);



	device_remove_file(&spi->dev, &dev_attr_status_show);



 err_status:

	kfree(st);

	return ret;

}



static int __devexit tle62x0_remove(struct spi_device *spi)

{

	struct tle62x0_state *st = spi_get_drvdata(spi);

	int ptr;



	for (ptr = 0; ptr < st->nr_gpio; ptr++)

		device_remove_file(&spi->dev, gpio_attrs[ptr]);



	kfree(st);

	return 0;

}



static struct spi_driver tle62x0_driver = {

	.driver = {

		.name	= "tle62x0",

		.owner	= THIS_MODULE,

	},

	.probe		= tle62x0_probe,

	.remove		= __devexit_p(tle62x0_remove),

};



static __init int tle62x0_init(void)

{

	return spi_register_driver(&tle62x0_driver);

}



static __exit void tle62x0_exit(void)

{

	spi_unregister_driver(&tle62x0_driver);

}



module_init(tle62x0_init);

module_exit(tle62x0_exit);



MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");

MODULE_DESCRIPTION("TLE62x0 SPI driver");

MODULE_LICENSE("GPL v2");

include/linux/spi/tle62x0.h

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+24 −0
Original line number Diff line number Diff line 
/*

 * tle62x0.h - platform glue to Infineon TLE62x0 driver chips

 *

 * Copyright 2007 Simtec Electronics

 *	Ben Dooks <ben@simtec.co.uk>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/



struct tle62x0_pdata {

	unsigned int		init_state;

	unsigned int		gpio_count;

};