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_ds2413.c | 71 +++++++++++++++++++++++------------
1 files changed, 46 insertions(+), 25 deletions(-)
diff --git a/kernel/drivers/w1/slaves/w1_ds2413.c b/kernel/drivers/w1/slaves/w1_ds2413.c
index 492e3d0..c8cfac5 100644
--- a/kernel/drivers/w1/slaves/w1_ds2413.c
+++ b/kernel/drivers/w1/slaves/w1_ds2413.c
@@ -1,11 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
@@ -24,12 +22,17 @@
#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
+#define W1_F3A_INVALID_PIO_STATE 0xFF
static ssize_t state_read(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_F3A_RETRIES;
+ ssize_t bytes_read = -EIO;
+ u8 state;
+
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);
@@ -42,22 +45,37 @@
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;
+next:
+ if (w1_reset_select_slave(sl))
+ goto out;
+
+ while (retries--) {
+ w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
+
+ state = w1_read_8(sl->master);
+ if ((state & 0x0F) == ((~state >> 4) & 0x0F)) {
+ /* complement is correct */
+ *buf = state;
+ bytes_read = 1;
+ goto out;
+ } else if (state == W1_F3A_INVALID_PIO_STATE) {
+ /* slave didn't respond, try to select it again */
+ dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \
+ "reselecting, retries left: %d\n", retries);
+ goto next;
+ }
+
+ if (w1_reset_resume_command(sl->master))
+ goto out; /* unrecoverable error */
+
+ dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries);
}
- w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
- *buf = w1_read_8(sl->master);
-
+out:
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;
+ dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
+ (bytes_read > 0) ? "succeeded" : "error", retries);
+ return bytes_read;
}
static BIN_ATTR_RO(state, 1);
@@ -69,6 +87,7 @@
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u8 w1_buf[3];
unsigned int retries = W1_F3A_RETRIES;
+ ssize_t bytes_written = -EIO;
if (count != 1 || off != 0)
return -EFAULT;
@@ -78,7 +97,7 @@
dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl))
- goto error;
+ goto out;
/* according to the DS2413 datasheet the most significant 6 bits
should be set to "1"s, so do it now */
@@ -91,18 +110,20 @@
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;
+ bytes_written = 1;
+ goto out;
}
if (w1_reset_resume_command(sl->master))
- goto error;
+ goto out; /* unrecoverable error */
+
+ dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
}
-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;
}
static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
@@ -122,7 +143,7 @@
NULL,
};
-static struct w1_family_ops w1_f3a_fops = {
+static const struct w1_family_ops w1_f3a_fops = {
.groups = w1_f3a_groups,
};
--
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