Commit 89610274 authored by Jean-François Dagenais's avatar Jean-François Dagenais Committed by Linus Torvalds
Browse files

w1: add 1-wire (w1) DS2408 8-Channel Addressable Switch support 



This DS2408 w1 slave driver is not complete for all the features of the
chip, but its sufficient if you use it as a simple IO expander.

[randy.dunlap@oracle.com: fix w1_ds2408.c printk formats]
Signed-off-by: default avatarJean-François Dagenais <dagenaisj@sonatest.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Cc: Matt Reimer <mreimer@vpop.net>
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 67dfd54c

drivers/w1/slaves/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -16,6 +16,13 @@ config W1_SLAVE_SMEM 
	  Say Y here if you want to connect 1-wire

	  simple 64bit memory rom(ds2401/ds2411/ds1990*) to your wire.



config W1_SLAVE_DS2408

        tristate "8-Channel Addressable Switch (IO Expander) 0x29 family support (DS2408)"

        help

          Say Y here if you want to use a 1-wire



		  DS2408 8-Channel Addressable Switch device support



config W1_SLAVE_DS2423

	tristate "Counter 1-wire device (DS2423)"

	select CRC16

drivers/w1/slaves/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 


obj-$(CONFIG_W1_SLAVE_THERM)	+= w1_therm.o

obj-$(CONFIG_W1_SLAVE_SMEM)	+= w1_smem.o

obj-$(CONFIG_W1_SLAVE_DS2408)   += w1_ds2408.o

obj-$(CONFIG_W1_SLAVE_DS2423)	+= w1_ds2423.o

obj-$(CONFIG_W1_SLAVE_DS2431)	+= w1_ds2431.o

obj-$(CONFIG_W1_SLAVE_DS2433)	+= w1_ds2433.o

drivers/w1/slaves/w1_ds2408.c

0 → 100644
+402 −0
Original line number Diff line number Diff line 
/*

 *	w1_ds2408.c - w1 family 29 (DS2408) driver

 *

 * Copyright (c) 2010 Jean-Francois Dagenais <dagenaisj@sonatest.com>

 *

 * This source code is licensed under the GNU General Public License,

 * Version 2. See the file COPYING for more details.

 */



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/device.h>

#include <linux/types.h>

#include <linux/delay.h>

#include <linux/slab.h>



#include "../w1.h"

#include "../w1_int.h"

#include "../w1_family.h"



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Jean-Francois Dagenais <dagenaisj@sonatest.com>");

MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO");





#define W1_F29_RETRIES		3



#define W1_F29_REG_LOGIG_STATE             0x88 /* R */

#define W1_F29_REG_OUTPUT_LATCH_STATE      0x89 /* R */

#define W1_F29_REG_ACTIVITY_LATCH_STATE    0x8A /* R */

#define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */

#define W1_F29_REG_COND_SEARCH_POL_SELECT  0x8C /* RW */

#define W1_F29_REG_CONTROL_AND_STATUS      0x8D /* RW */



#define W1_F29_FUNC_READ_PIO_REGS          0xF0

#define W1_F29_FUNC_CHANN_ACCESS_READ      0xF5

#define W1_F29_FUNC_CHANN_ACCESS_WRITE     0x5A

/* also used to write the control/status reg (0x8D): */

#define W1_F29_FUNC_WRITE_COND_SEARCH_REG  0xCC

#define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3



#define W1_F29_SUCCESS_CONFIRM_BYTE        0xAA



static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)

{

	u8 wrbuf[3];

	dev_dbg(&sl->dev,

			"Reading with slave: %p, reg addr: %0#4x, buff addr: %p",

			sl, (unsigned int)address, buf);



	if (!buf)

		return -EINVAL;



	mutex_lock(&sl->master->mutex);

	dev_dbg(&sl->dev, "mutex locked");



	if (w1_reset_select_slave(sl)) {

		mutex_unlock(&sl->master->mutex);

		return -EIO;

	}



	wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS;

	wrbuf[1] = address;

	wrbuf[2] = 0;

	w1_write_block(sl->master, wrbuf, 3);

	*buf = w1_read_8(sl->master);



	mutex_unlock(&sl->master->mutex);

	dev_dbg(&sl->dev, "mutex unlocked");

	return 1;

}



static ssize_t w1_f29_read_state(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	dev_dbg(&kobj_to_w1_slave(kobj)->dev,

		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",

		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf);

}



static ssize_t w1_f29_read_output(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	dev_dbg(&kobj_to_w1_slave(kobj)->dev,

		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",

		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj),

					 W1_F29_REG_OUTPUT_LATCH_STATE, buf);

}



static ssize_t w1_f29_read_activity(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	dev_dbg(&kobj_to_w1_slave(kobj)->dev,

		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",

		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj),

					 W1_F29_REG_ACTIVITY_LATCH_STATE, buf);

}



static ssize_t w1_f29_read_cond_search_mask(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	dev_dbg(&kobj_to_w1_slave(kobj)->dev,

		"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",

		bin_attr->attr.name, kobj, (unsigned int)off, count, buf);

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj),

		W1_F29_REG_COND_SEARCH_SELECT_MASK, buf);

}



static ssize_t w1_f29_read_cond_search_polarity(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj),

		W1_F29_REG_COND_SEARCH_POL_SELECT, buf);

}



static ssize_t w1_f29_read_status_control(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	if (count != 1 || off != 0)

		return -EFAULT;

	return _read_reg(kobj_to_w1_slave(kobj),

		W1_F29_REG_CONTROL_AND_STATUS, buf);

}









static ssize_t w1_f29_write_output(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	u8 w1_buf[3];

	u8 readBack;

	unsigned int retries = W1_F29_RETRIES;



	if (count != 1 || off != 0)

		return -EFAULT;



	dev_dbg(&sl->dev, "locking mutex for write_output");

	mutex_lock(&sl->master->mutex);

	dev_dbg(&sl->dev, "mutex locked");



	if (w1_reset_select_slave(sl))

		goto error;



	while (retries--) {

		w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE;

		w1_buf[1] = *buf;

		w1_buf[2] = ~(*buf);

		w1_write_block(sl->master, w1_buf, 3);



		readBack = w1_read_8(sl->master);

		/* here the master could read another byte which

		   would be the PIO reg (the actual pin logic state)

		   since in this driver we don't know which pins are

		   in and outs, there's no value to read the state and

		   compare. with (*buf) so end this command abruptly: */

		if (w1_reset_resume_command(sl->master))

			goto error;



		if (readBack != 0xAA) {

			/* try again, the slave is ready for a command */

			continue;

		}



		/* go read back the output latches */

		/* (the direct effect of the write above) */

		w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS;

		w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE;

		w1_buf[2] = 0;

		w1_write_block(sl->master, w1_buf, 3);

		/* read the result of the READ_PIO_REGS command */

		if (w1_read_8(sl->master) == *buf) {

			/* success! */

			mutex_unlock(&sl->master->mutex);

			dev_dbg(&sl->dev,

				"mutex unlocked, retries:%d", retries);

			return 1;

		}

	}

error:

	mutex_unlock(&sl->master->mutex);

	dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);



	return -EIO;

}





/**

 * Writing to the activity file resets the activity latches.

 */

static ssize_t w1_f29_write_activity(

	struct file *filp, struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf, loff_t off, size_t count)

{

	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	unsigned int retries = W1_F29_RETRIES;



	if (count != 1 || off != 0)

		return -EFAULT;



	mutex_lock(&sl->master->mutex);



	if (w1_reset_select_slave(sl))

		goto error;



	while (retries--) {

		w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES);

		if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) {

			mutex_unlock(&sl->master->mutex);

			return 1;

		}

		if (w1_reset_resume_command(sl->master))

			goto error;

	}



error:

	mutex_unlock(&sl->master->mutex);

	return -EIO;

}



static ssize_t w1_f29_write_status_control(

	struct file *filp,

	struct kobject *kobj,

	struct bin_attribute *bin_attr,

	char *buf,

	loff_t off,

	size_t count)

{

	struct w1_slave *sl = kobj_to_w1_slave(kobj);

	u8 w1_buf[4];

	unsigned int retries = W1_F29_RETRIES;



	if (count != 1 || off != 0)

		return -EFAULT;



	mutex_lock(&sl->master->mutex);



	if (w1_reset_select_slave(sl))

		goto error;



	while (retries--) {

		w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG;

		w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS;

		w1_buf[2] = 0;

		w1_buf[3] = *buf;



		w1_write_block(sl->master, w1_buf, 4);

		if (w1_reset_resume_command(sl->master))

			goto error;



		w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS;

		w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS;

		w1_buf[2] = 0;



		w1_write_block(sl->master, w1_buf, 3);

		if (w1_read_8(sl->master) == *buf) {

			/* success! */

			mutex_unlock(&sl->master->mutex);

			return 1;

		}

	}

error:

	mutex_unlock(&sl->master->mutex);



	return -EIO;

}







#define NB_SYSFS_BIN_FILES 6

static struct bin_attribute w1_f29_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {

	{

		.attr =	{

			.name = "state",

			.mode = S_IRUGO,

		},

		.size = 1,

		.read = w1_f29_read_state,

	},

	{

		.attr =	{

			.name = "output",

			.mode = S_IRUGO | S_IWUSR | S_IWGRP,

		},

		.size = 1,

		.read = w1_f29_read_output,

		.write = w1_f29_write_output,

	},

	{

		.attr =	{

			.name = "activity",

			.mode = S_IRUGO,

		},

		.size = 1,

		.read = w1_f29_read_activity,

		.write = w1_f29_write_activity,

	},

	{

		.attr =	{

			.name = "cond_search_mask",

			.mode = S_IRUGO,

		},

		.size = 1,

		.read = w1_f29_read_cond_search_mask,

		.write = 0,

	},

	{

		.attr =	{

			.name = "cond_search_polarity",

			.mode = S_IRUGO,

		},

		.size = 1,

		.read = w1_f29_read_cond_search_polarity,

		.write = 0,

	},

	{

		.attr =	{

			.name = "status_control",

			.mode = S_IRUGO | S_IWUSR | S_IWGRP,

		},

		.size = 1,

		.read = w1_f29_read_status_control,

		.write = w1_f29_write_status_control,

	}

};



static int w1_f29_add_slave(struct w1_slave *sl)

{

	int err = 0;

	int i;



	for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)

		err = sysfs_create_bin_file(

			&sl->dev.kobj,

			&(w1_f29_sysfs_bin_files[i]));

	if (err)

		while (--i >= 0)

			sysfs_remove_bin_file(&sl->dev.kobj,

				&(w1_f29_sysfs_bin_files[i]));

	return err;

}



static void w1_f29_remove_slave(struct w1_slave *sl)

{

	int i;

	for (i = NB_SYSFS_BIN_FILES; i <= 0; --i)

		sysfs_remove_bin_file(&sl->dev.kobj,

			&(w1_f29_sysfs_bin_files[i]));

}



static struct w1_family_ops w1_f29_fops = {

	.add_slave      = w1_f29_add_slave,

	.remove_slave   = w1_f29_remove_slave,

};



static struct w1_family w1_family_29 = {

	.fid = W1_FAMILY_DS2408,

	.fops = &w1_f29_fops,

};



static int __init w1_f29_init(void)

{

	return w1_register_family(&w1_family_29);

}



static void __exit w1_f29_exit(void)

{

	w1_unregister_family(&w1_family_29);

}



module_init(w1_f29_init);

module_exit(w1_f29_exit);

drivers/w1/w1_family.h

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#define W1_THERM_DS1822  	0x22

#define W1_EEPROM_DS2433  	0x23

#define W1_THERM_DS18B20 	0x28

#define W1_FAMILY_DS2408	0x29

#define W1_EEPROM_DS2431	0x2D

#define W1_FAMILY_DS2760	0x30

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