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>

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index cb3fc3c6b0d17a4615c2f522bd5fe4d15d4d7919..faddc2488c91227fe8c5ce1466eb2e6710fe433f 100644 (file)
--- 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;
 }