w1: add support for DS2413 Dual Channel Addressable Switch

Also fixes some whitespace inconsistency in Kconfig and w1_family.h when
DS2408 chip support was added.

Signed-off-by: Mariusz Bialonczyk <manio@skyboo.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 189 insertions, 5 deletions

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index 67526690acbc..762561fbabbf 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -17,11 +17,16 @@ config W1_SLAVE_SMEM
           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
+        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
 
-                  DS2408 8-Channel Addressable Switch device support
+config W1_SLAVE_DS2413
+        tristate "Dual Channel Addressable Switch 0x3a family support (DS2413)"
+        help
+          Say Y here if you want to use a 1-wire
+          DS2413 Dual Channel Addressable Switch device support
 
 config W1_SLAVE_DS2423
         tristate "Counter 1-wire device (DS2423)"
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index 05188f6aab5a..06529f3157ab 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -4,7 +4,8 @@
 
 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_DS2408)   += w1_ds2408.o
+obj-$(CONFIG_W1_SLAVE_DS2413)   += w1_ds2413.o
 obj-$(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_ds2413.c b/drivers/w1/slaves/w1_ds2413.c
new file mode 100644
index 000000000000..829786252c6b
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2413.c
@@ -0,0 +1,177 @@
+/*
+ * w1_ds2413.c - w1 family 3a (DS2413) driver
+ * based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
+ *
+ * Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
+ *
+ * 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("Mariusz Bialonczyk <manio@skyboo.net>");
+MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
+
+#define W1_F3A_RETRIES                     3
+#define W1_F3A_FUNC_PIO_ACCESS_READ        0xF5
+#define W1_F3A_FUNC_PIO_ACCESS_WRITE       0x5A
+#define W1_F3A_SUCCESS_CONFIRM_BYTE        0xAA
+
+static ssize_t w1_f3a_read_state(
+        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);
+        dev_dbg(&sl->dev,
+                "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
+                bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
+
+        if (off != 0)
+                return 0;
+        if (!buf)
+                return -EINVAL;
+
+        mutex_lock(&sl->master->bus_mutex);
+        dev_dbg(&sl->dev, "mutex locked");
+
+        if (w1_reset_select_slave(sl)) {
+                mutex_unlock(&sl->master->bus_mutex);
+                return -EIO;
+        }
+
+        w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
+        *buf = w1_read_8(sl->master);
+
+        mutex_unlock(&sl->master->bus_mutex);
+        dev_dbg(&sl->dev, "mutex unlocked");
+
+        /* check for correct complement */
+        if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
+                return -EIO;
+        else
+                return 1;
+}
+
+static ssize_t w1_f3a_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];
+        unsigned int retries = W1_F3A_RETRIES;
+
+        if (count != 1 || off != 0)
+                return -EFAULT;
+
+        dev_dbg(&sl->dev, "locking mutex for write_output");
+        mutex_lock(&sl->master->bus_mutex);
+        dev_dbg(&sl->dev, "mutex locked");
+
+        if (w1_reset_select_slave(sl))
+                goto error;
+
+        /* according to the DS2413 datasheet the most significant 6 bits
+           should be set to "1"s, so do it now */
+        *buf = *buf | 0xFC;
+
+        while (retries--) {
+                w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
+                w1_buf[1] = *buf;
+                w1_buf[2] = ~(*buf);
+                w1_write_block(sl->master, w1_buf, 3);
+
+                if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
+                        mutex_unlock(&sl->master->bus_mutex);
+                        dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
+                        return 1;
+                }
+                if (w1_reset_resume_command(sl->master))
+                        goto error;
+        }
+
+error:
+        mutex_unlock(&sl->master->bus_mutex);
+        dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
+        return -EIO;
+}
+
+#define NB_SYSFS_BIN_FILES 2
+static struct bin_attribute w1_f3a_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
+        {
+                .attr = {
+                        .name = "state",
+                        .mode = S_IRUGO,
+                },
+                .size = 1,
+                .read = w1_f3a_read_state,
+        },
+        {
+                .attr = {
+                        .name = "output",
+                        .mode = S_IRUGO | S_IWUSR | S_IWGRP,
+                },
+                .size = 1,
+                .write = w1_f3a_write_output,
+        }
+};
+
+static int w1_f3a_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_f3a_sysfs_bin_files[i]));
+        if (err)
+                while (--i >= 0)
+                        sysfs_remove_bin_file(&sl->dev.kobj,
+                                &(w1_f3a_sysfs_bin_files[i]));
+        return err;
+}
+
+static void w1_f3a_remove_slave(struct w1_slave *sl)
+{
+        int i;
+        for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
+                sysfs_remove_bin_file(&sl->dev.kobj,
+                        &(w1_f3a_sysfs_bin_files[i]));
+}
+
+static struct w1_family_ops w1_f3a_fops = {
+        .add_slave      = w1_f3a_add_slave,
+        .remove_slave   = w1_f3a_remove_slave,
+};
+
+static struct w1_family w1_family_3a = {
+        .fid = W1_FAMILY_DS2413,
+        .fops = &w1_f3a_fops,
+};
+
+static int __init w1_f3a_init(void)
+{
+        return w1_register_family(&w1_family_3a);
+}
+
+static void __exit w1_f3a_exit(void)
+{
+        w1_unregister_family(&w1_family_3a);
+}
+
+module_init(w1_f3a_init);
+module_exit(w1_f3a_exit);
diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h
index a1f0ce151d53..625dd08f775f 100644
--- a/drivers/w1/w1_family.h
+++ b/drivers/w1/w1_family.h
@@ -39,6 +39,7 @@
 #define W1_EEPROM_DS2431        0x2D
 #define W1_FAMILY_DS2760        0x30
 #define W1_FAMILY_DS2780        0x32
+#define W1_FAMILY_DS2413        0x3A
 #define W1_THERM_DS1825         0x3B
 #define W1_FAMILY_DS2781        0x3D
 #define W1_THERM_DS28EA00       0x42