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Diffstat (limited to 'drivers/w1/slaves/w1_ds2408.c')
-rw-r--r--drivers/w1/slaves/w1_ds2408.c134
1 files changed, 67 insertions, 67 deletions
diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c
index b535d5ec35b6..30d1d574d2e5 100644
--- a/drivers/w1/slaves/w1_ds2408.c
+++ b/drivers/w1/slaves/w1_ds2408.c
@@ -1,10 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
@@ -37,12 +35,12 @@
#define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA
-static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
+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);
+
+ dev_dbg(&sl->dev, "Reading with slave: %p, reg addr: %0#4x, buff addr: %p",
+ sl, (unsigned int)address, buf);
if (!buf)
return -EINVAL;
@@ -67,8 +65,8 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
}
static ssize_t state_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf, loff_t off,
- size_t count)
+ const 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",
@@ -79,7 +77,7 @@ static ssize_t state_read(struct file *filp, struct kobject *kobj,
}
static ssize_t output_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
+ const struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
dev_dbg(&kobj_to_w1_slave(kobj)->dev,
@@ -92,7 +90,7 @@ static ssize_t output_read(struct file *filp, struct kobject *kobj,
}
static ssize_t activity_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
+ const struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
dev_dbg(&kobj_to_w1_slave(kobj)->dev,
@@ -105,8 +103,8 @@ static ssize_t activity_read(struct file *filp, struct kobject *kobj,
}
static ssize_t cond_search_mask_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
- loff_t off, size_t count)
+ const 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",
@@ -119,7 +117,7 @@ static ssize_t cond_search_mask_read(struct file *filp, struct kobject *kobj,
static ssize_t cond_search_polarity_read(struct file *filp,
struct kobject *kobj,
- struct bin_attribute *bin_attr,
+ const struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
if (count != 1 || off != 0)
@@ -129,8 +127,8 @@ static ssize_t cond_search_polarity_read(struct file *filp,
}
static ssize_t status_control_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
- loff_t off, size_t count)
+ const struct bin_attribute *bin_attr,
+ char *buf, loff_t off, size_t count)
{
if (count != 1 || off != 0)
return -EFAULT;
@@ -138,14 +136,37 @@ static ssize_t status_control_read(struct file *filp, struct kobject *kobj,
W1_F29_REG_CONTROL_AND_STATUS, buf);
}
+#ifdef CONFIG_W1_SLAVE_DS2408_READBACK
+static bool optional_read_back_valid(struct w1_slave *sl, u8 expected)
+{
+ u8 w1_buf[3];
+
+ if (w1_reset_resume_command(sl->master))
+ return false;
+
+ 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);
+
+ return (w1_read_8(sl->master) == expected);
+}
+#else
+static bool optional_read_back_valid(struct w1_slave *sl, u8 expected)
+{
+ return true;
+}
+#endif
+
static ssize_t output_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
+ const 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;
+ ssize_t bytes_written = -EIO;
if (count != 1 || off != 0)
return -EFAULT;
@@ -155,62 +176,41 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl))
- goto error;
+ goto out;
- while (retries--) {
+ do {
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);
+ w1_write_block(sl->master, w1_buf, 3);
- if (readBack != W1_F29_SUCCESS_CONFIRM_BYTE) {
- if (w1_reset_resume_command(sl->master))
- goto error;
- /* try again, the slave is ready for a command */
- continue;
+ if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE &&
+ optional_read_back_valid(sl, *buf)) {
+ bytes_written = 1;
+ goto out;
}
-#ifdef CONFIG_W1_SLAVE_DS2408_READBACK
- /* 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;
+ goto out; /* unrecoverable error */
+ /* try again, the slave is ready for a command */
+ } while (--retries);
- /* 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)
-#endif
- {
- /* success! */
- mutex_unlock(&sl->master->bus_mutex);
- dev_dbg(&sl->dev,
- "mutex unlocked, retries:%d", retries);
- return 1;
- }
- }
-error:
+out:
mutex_unlock(&sl->master->bus_mutex);
- dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
- return -EIO;
+ dev_dbg(&sl->dev, "%s, mutex unlocked retries:%d\n",
+ (bytes_written > 0) ? "succeeded" : "error", retries);
+
+ return bytes_written;
}
-/**
+/*
* Writing to the activity file resets the activity latches.
*/
static ssize_t activity_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
+ const struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
@@ -240,8 +240,8 @@ error:
}
static ssize_t status_control_write(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr, char *buf,
- loff_t off, size_t count)
+ const 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];
@@ -292,7 +292,7 @@ static int w1_f29_disable_test_mode(struct w1_slave *sl)
{
int res;
u8 magic[10] = {0x96, };
- u64 rn = le64_to_cpu(*((u64*)&sl->reg_num));
+ u64 rn = le64_to_cpu(*((u64 *)&sl->reg_num));
memcpy(&magic[1], &rn, 8);
magic[9] = 0x3C;
@@ -310,14 +310,14 @@ out:
return res;
}
-static BIN_ATTR_RO(state, 1);
-static BIN_ATTR_RW(output, 1);
-static BIN_ATTR_RW(activity, 1);
-static BIN_ATTR_RO(cond_search_mask, 1);
-static BIN_ATTR_RO(cond_search_polarity, 1);
-static BIN_ATTR_RW(status_control, 1);
+static const BIN_ATTR_RO(state, 1);
+static const BIN_ATTR_RW(output, 1);
+static const BIN_ATTR_RW(activity, 1);
+static const BIN_ATTR_RO(cond_search_mask, 1);
+static const BIN_ATTR_RO(cond_search_polarity, 1);
+static const BIN_ATTR_RW(status_control, 1);
-static struct bin_attribute *w1_f29_bin_attrs[] = {
+static const struct bin_attribute *const w1_f29_bin_attrs[] = {
&bin_attr_state,
&bin_attr_output,
&bin_attr_activity,
@@ -336,7 +336,7 @@ static const struct attribute_group *w1_f29_groups[] = {
NULL,
};
-static struct w1_family_ops w1_f29_fops = {
+static const struct w1_family_ops w1_f29_fops = {
.add_slave = w1_f29_disable_test_mode,
.groups = w1_f29_groups,
};
generated by cgit (git 2.34.1) at 2025-12-26 11:09:26 +0000