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>

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;
 }