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    Subject[PATCH] w1: Add DS2408 8-Channel Addressable Switch 1-wire slave support
    From
    Date
    from: Jean-François Dagenais <jeff.dagenais@gmail.com>

    This patch depends on patch "[PATCH] w1: Add 1-wire reset and resume API (0xA5)" 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.

    Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com>
    ---
    :100644 100644 f0c9096... cd1b724... M drivers/w1/slaves/Kconfig
    :100644 100644 3c76350... 75e3913... M drivers/w1/slaves/Makefile
    :000000 100644 0000000... 3547e80... A drivers/w1/slaves/w1_ds2408.c
    :100644 100644 f3b636d... 7513759... M drivers/w1/w1_family.h
    drivers/w1/slaves/Kconfig | 7 +
    drivers/w1/slaves/Makefile | 1 +
    drivers/w1/slaves/w1_ds2408.c | 402 +++++++++++++++++++++++++++++++++++++++++
    drivers/w1/w1_family.h | 1 +
    4 files changed, 411 insertions(+), 0 deletions(-)

    diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
    index f0c9096..cd1b724 100644
    --- a/drivers/w1/slaves/Kconfig
    +++ b/drivers/w1/slaves/Kconfig
    @@ -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
    diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
    index 3c76350..75e3913 100644
    --- a/drivers/w1/slaves/Makefile
    +++ b/drivers/w1/slaves/Makefile
    @@ -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
    diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c
    new file mode 100644
    index 0000000..3547e80
    --- /dev/null
    +++ b/drivers/w1/slaves/w1_ds2408.c
    @@ -0,0 +1,402 @@
    +/*
    + * 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: %lu, 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: %lu, 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: %lu, 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: %lu, 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);
    diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h
    index f3b636d..7513759 100644
    --- a/drivers/w1/w1_family.h
    +++ b/drivers/w1/w1_family.h
    @@ -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

    --
    1.7.4.1

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