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path: root/drivers/w1/slaves/w1_therm.c
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Diffstat (limited to 'drivers/w1/slaves/w1_therm.c')
-rw-r--r--drivers/w1/slaves/w1_therm.c72
1 files changed, 34 insertions, 38 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index fb28acaeed6..2c8dff9f77d 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -37,31 +37,33 @@ MODULE_LICENSE("GPL");
MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
+/* Allow the strong pullup to be disabled, but default to enabled.
+ * If it was disabled a parasite powered device might not get the require
+ * current to do a temperature conversion. If it is enabled parasite powered
+ * devices have a better chance of getting the current required.
+ */
+static int w1_strong_pullup = 1;
+module_param_named(strong_pullup, w1_strong_pullup, int, 0);
+
static u8 bad_roms[][9] = {
{0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
{}
};
-static ssize_t w1_therm_read_bin(struct kobject *, struct bin_attribute *,
- char *, loff_t, size_t);
+static ssize_t w1_therm_read(struct device *device,
+ struct device_attribute *attr, char *buf);
-static struct bin_attribute w1_therm_bin_attr = {
- .attr = {
- .name = "w1_slave",
- .mode = S_IRUGO,
- },
- .size = W1_SLAVE_DATA_SIZE,
- .read = w1_therm_read_bin,
-};
+static struct device_attribute w1_therm_attr =
+ __ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL);
static int w1_therm_add_slave(struct w1_slave *sl)
{
- return sysfs_create_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
+ return device_create_file(&sl->dev, &w1_therm_attr);
}
static void w1_therm_remove_slave(struct w1_slave *sl)
{
- sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
+ device_remove_file(&sl->dev, &w1_therm_attr);
}
static struct w1_family_ops w1_therm_fops = {
@@ -160,30 +162,19 @@ static int w1_therm_check_rom(u8 rom[9])
return 0;
}
-static ssize_t w1_therm_read_bin(struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t off, size_t count)
+static ssize_t w1_therm_read(struct device *device,
+ struct device_attribute *attr, char *buf)
{
- struct w1_slave *sl = kobj_to_w1_slave(kobj);
+ struct w1_slave *sl = dev_to_w1_slave(device);
struct w1_master *dev = sl->master;
u8 rom[9], crc, verdict;
int i, max_trying = 10;
+ ssize_t c = PAGE_SIZE;
- mutex_lock(&sl->master->mutex);
+ mutex_lock(&dev->mutex);
- if (off > W1_SLAVE_DATA_SIZE) {
- count = 0;
- goto out;
- }
- if (off + count > W1_SLAVE_DATA_SIZE) {
- count = 0;
- goto out;
- }
-
- memset(buf, 0, count);
memset(rom, 0, sizeof(rom));
- count = 0;
verdict = 0;
crc = 0;
@@ -192,15 +183,20 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj,
int count = 0;
unsigned int tm = 750;
+ /* 750ms strong pullup (or delay) after the convert */
+ if (w1_strong_pullup)
+ w1_next_pullup(dev, tm);
w1_write_8(dev, W1_CONVERT_TEMP);
-
- msleep(tm);
+ if (!w1_strong_pullup)
+ msleep(tm);
if (!w1_reset_select_slave(sl)) {
w1_write_8(dev, W1_READ_SCRATCHPAD);
if ((count = w1_read_block(dev, rom, 9)) != 9) {
- dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
+ dev_warn(device, "w1_read_block() "
+ "returned %u instead of 9.\n",
+ count);
}
crc = w1_calc_crc8(rom, 8);
@@ -215,22 +211,22 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj,
}
for (i = 0; i < 9; ++i)
- count += sprintf(buf + count, "%02x ", rom[i]);
- count += sprintf(buf + count, ": crc=%02x %s\n",
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]);
+ c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
crc, (verdict) ? "YES" : "NO");
if (verdict)
memcpy(sl->rom, rom, sizeof(sl->rom));
else
- dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
+ dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n");
for (i = 0; i < 9; ++i)
- count += sprintf(buf + count, "%02x ", sl->rom[i]);
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);
- count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
-out:
+ c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
+ w1_convert_temp(rom, sl->family->fid));
mutex_unlock(&dev->mutex);
- return count;
+ return PAGE_SIZE - c;
}
static int __init w1_therm_init(void)