From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB
---
kernel/drivers/w1/slaves/w1_ds2408.c | 82 ++++++++++++++++++++--------------------
1 files changed, 41 insertions(+), 41 deletions(-)
diff --git a/kernel/drivers/w1/slaves/w1_ds2408.c b/kernel/drivers/w1/slaves/w1_ds2408.c
index b535d5e..ad102c5 100644
--- a/kernel/drivers/w1/slaves/w1_ds2408.c
+++ b/kernel/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>
@@ -138,14 +136,37 @@
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,
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;
@@ -155,54 +176,33 @@
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);
-
- 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;
}
@@ -336,7 +336,7 @@
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,
};
--
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