diff options
author | Jaghathiswari Rankappagounder Natarajan <jaghu@google.com> | 2017-08-30 16:34:34 -0700 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-31 18:50:14 +0200 |
commit | b78165f028713121609dae40f10246da6293a281 (patch) | |
tree | b4323705fccb967873d6018b6f3c05c622309eba /drivers | |
parent | 2eb7954809bf26de27bc3a2fea4eef606bbf4482 (diff) |
drivers: w1: refactor w1_slave_show to make the temp reading functionality separate
Inside the w1_slave_show function refactor the code to read the temp
into a separate function.
Signed-off-by: Jaghathiswari Rankappagounder Natarajan <jaghu@google.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/w1/slaves/w1_therm.c | 82 |
1 files changed, 51 insertions, 31 deletions
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c index cb3fc3c6b0d1..faddc2488c91 100644 --- a/drivers/w1/slaves/w1_therm.c +++ b/drivers/w1/slaves/w1_therm.c @@ -59,6 +59,12 @@ struct w1_therm_family_data { atomic_t refcnt; }; +struct therm_info { + u8 rom[9]; + u8 crc; + u8 verdict; +}; + /* return the address of the refcnt in the family data */ #define THERM_REFCNT(family_data) \ (&((struct w1_therm_family_data *)family_data)->refcnt) @@ -422,33 +428,31 @@ static ssize_t w1_slave_store(struct device *device, return ret ? : size; } -static ssize_t w1_slave_show(struct device *device, - struct device_attribute *attr, char *buf) +static ssize_t read_therm(struct device *device, + struct w1_slave *sl, struct therm_info *info) { - struct w1_slave *sl = dev_to_w1_slave(device); struct w1_master *dev = sl->master; - u8 rom[9], crc, verdict, external_power; - int i, ret, max_trying = 10; - ssize_t c = PAGE_SIZE; + u8 external_power; + int ret, max_trying = 10; u8 *family_data = sl->family_data; ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) - goto post_unlock; + goto error; - if (!sl->family_data) { + if (!family_data) { ret = -ENODEV; - goto pre_unlock; + goto mt_unlock; } /* prevent the slave from going away in sleep */ atomic_inc(THERM_REFCNT(family_data)); - memset(rom, 0, sizeof(rom)); + memset(info->rom, 0, sizeof(info->rom)); while (max_trying--) { - verdict = 0; - crc = 0; + info->verdict = 0; + info->crc = 0; if (!w1_reset_select_slave(sl)) { int count = 0; @@ -474,47 +478,69 @@ static ssize_t w1_slave_show(struct device *device, sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { ret = -EINTR; - goto post_unlock; + goto dec_refcnt; } ret = mutex_lock_interruptible(&dev->bus_mutex); if (ret != 0) - goto post_unlock; + goto dec_refcnt; } else if (!w1_strong_pullup) { sleep_rem = msleep_interruptible(tm); if (sleep_rem != 0) { ret = -EINTR; - goto pre_unlock; + goto dec_refcnt; } } if (!w1_reset_select_slave(sl)) { w1_write_8(dev, W1_READ_SCRATCHPAD); - count = w1_read_block(dev, rom, 9); + count = w1_read_block(dev, info->rom, 9); if (count != 9) { dev_warn(device, "w1_read_block() " "returned %u instead of 9.\n", count); } - crc = w1_calc_crc8(rom, 8); + info->crc = w1_calc_crc8(info->rom, 8); - if (rom[8] == crc) - verdict = 1; + if (info->rom[8] == info->crc) + info->verdict = 1; } } - if (verdict) + if (info->verdict) break; } +dec_refcnt: + atomic_dec(THERM_REFCNT(family_data)); +mt_unlock: + mutex_unlock(&dev->bus_mutex); +error: + return ret; +} + +static ssize_t w1_slave_show(struct device *device, + struct device_attribute *attr, char *buf) +{ + struct w1_slave *sl = dev_to_w1_slave(device); + struct therm_info info; + u8 *family_data = sl->family_data; + int ret, i; + ssize_t c = PAGE_SIZE; + u8 fid = sl->family->fid; + + ret = read_therm(device, sl, &info); + if (ret) + return ret; + for (i = 0; i < 9; ++i) - c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]); + c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", info.rom[i]); c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", - crc, (verdict) ? "YES" : "NO"); - if (verdict) - memcpy(family_data, rom, sizeof(rom)); + info.crc, (info.verdict) ? "YES" : "NO"); + if (info.verdict) + memcpy(family_data, info.rom, sizeof(info.rom)); else dev_warn(device, "Read failed CRC check\n"); @@ -523,14 +549,8 @@ static ssize_t w1_slave_show(struct device *device, ((u8 *)family_data)[i]); c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", - w1_convert_temp(rom, sl->family->fid)); + w1_convert_temp(info.rom, fid)); ret = PAGE_SIZE - c; - -pre_unlock: - mutex_unlock(&dev->bus_mutex); - -post_unlock: - atomic_dec(THERM_REFCNT(family_data)); return ret; } |