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w1: ds2413: output_write() cosmetic fixes / simplify

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Make the output_write simpler.
Based on Jean-Francois Dagenais code from:
49695ac46861 ("w1: ds2408: reset on output_write retry with readback")

Signed-off-by: Mariusz Bialonczyk <manio@skyboo.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mariusz Bialonczyk 2019-05-20 09:05:55 +02:00 committed by Greg Kroah-Hartman
parent ae29783d33
commit ae2ee27aa9
1 changed files with 11 additions and 8 deletions
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19
drivers/w1/slaves/w1_ds2413.c
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@ -69,6 +69,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
struct w1_slave *sl = kobj_to_w1_slave(kobj); struct w1_slave *sl = kobj_to_w1_slave(kobj);
u8 w1_buf[3]; u8 w1_buf[3];
unsigned int retries = W1_F3A_RETRIES; unsigned int retries = W1_F3A_RETRIES;
ssize_t bytes_written = -EIO;
if (count != 1 || off != 0) if (count != 1 || off != 0)
return -EFAULT; return -EFAULT;
@ -78,7 +79,7 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
dev_dbg(&sl->dev, "mutex locked"); dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl)) if (w1_reset_select_slave(sl))
goto error; goto out;
/* according to the DS2413 datasheet the most significant 6 bits /* according to the DS2413 datasheet the most significant 6 bits
should be set to "1"s, so do it now */ should be set to "1"s, so do it now */
@ -91,18 +92,20 @@ static ssize_t output_write(struct file *filp, struct kobject *kobj,
w1_write_block(sl->master, w1_buf, 3); w1_write_block(sl->master, w1_buf, 3);
if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) { if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
mutex_unlock(&sl->master->bus_mutex); bytes_written = 1;
dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries); goto out;
return 1;
} }
if (w1_reset_resume_command(sl->master)) 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); mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
return -EIO; (bytes_written > 0) ? "succeeded" : "error", retries);
return bytes_written;
} }
static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1); static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);