[media] em28xx-i2c: Fix error code for I2C error transfers

Follow the error codes for I2C as described at Documentation/i2c/fault-codes.

In the case of the I2C status register (0x05), this is mapped into:

	- ENXIO - when reg 05 returns 0x10
	- ETIMEDOUT - when the device is not temporarily not responding
		      (e. g. reg 05 returning something not 0x10 or 0x00)
	- EIO - for generic I/O errors that don't fit into the above.

In the specific case of 0-byte reads, used only during I2C device
probing, it keeps returning -ENODEV.

TODO: return EBUSY when reg 05 returns 0x20 on em2874 and upper.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 20 insertions, 17 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index 342f35ad6070..76f956635bd9 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -80,7 +80,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
                 if (ret == 0x80 + len - 1)
                         return len;
                 if (ret == 0x94 + len - 1) {
-                        return -ENODEV;
+                        return -ENXIO;
                 }
                 if (ret < 0) {
                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -90,7 +90,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
                 msleep(5);
         }
         em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
-        return -EIO;
+        return -ETIMEDOUT;
 }
 
 /*
@@ -123,7 +123,7 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
                 if (ret == 0x84 + len - 1)
                         break;
                 if (ret == 0x94 + len - 1) {
-                        return -ENODEV;
+                        return -ENXIO;
                 }
                 if (ret < 0) {
                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -199,7 +199,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
                 if (ret == 0) /* success */
                         return len;
                 if (ret == 0x10) {
-                        return -ENODEV;
+                        return -ENXIO;
                 }
                 if (ret < 0) {
                         em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
@@ -213,9 +213,8 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
                  * (even with high payload) ...
                  */
         }
-
-        em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
-        return -EIO;
+        em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n", addr, ret);
+        return -ETIMEDOUT;
 }
 
 /*
@@ -245,7 +244,7 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
          * bytes if we are on bus B AND there was no write attempt to the
          * specified slave address before AND no device is present at the
          * requested slave address.
-         * Anyway, the next check will fail with -ENODEV in this case, so avoid
+         * Anyway, the next check will fail with -ENXIO in this case, so avoid
          * spamming the system log on device probing and do nothing here.
          */
 
@@ -259,10 +258,10 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
                 return ret;
         }
         if (ret == 0x10)
-                return -ENODEV;
+                return -ENXIO;
 
         em28xx_warn("unknown i2c error (status=%i)\n", ret);
-        return -EIO;
+        return -ETIMEDOUT;
 }
 
 /*
@@ -318,7 +317,7 @@ static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
         if (!ret)
                 return len;
         else if (ret > 0)
-                return -ENODEV;
+                return -ENXIO;
 
         return ret;
         /*
@@ -356,7 +355,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
          * bytes if we are on bus B AND there was no write attempt to the
          * specified slave address before AND no device is present at the
          * requested slave address.
-         * Anyway, the next check will fail with -ENODEV in this case, so avoid
+         * Anyway, the next check will fail with -ENXIO in this case, so avoid
          * spamming the system log on device probing and do nothing here.
          */
 
@@ -369,7 +368,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf,
         if (!ret)
                 return len;
         else if (ret > 0)
-                return -ENODEV;
+                return -ENXIO;
 
         return ret;
         /*
@@ -410,7 +409,7 @@ static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr)
                 rc = em2800_i2c_check_for_device(dev, addr);
         else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B)
                 rc = em25xx_bus_B_check_for_device(dev, addr);
-        if (rc == -ENODEV) {
+        if (rc == -ENXIO) {
                 if (i2c_debug)
                         printk(" no device\n");
         }
@@ -498,11 +497,15 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
                                (msgs[i].flags & I2C_M_RD) ? "read" : "write",
                                i == num - 1 ? "stop" : "nonstop",
                                addr, msgs[i].len);
-                if (!msgs[i].len) { /* no len: check only for device presence */
+                if (!msgs[i].len) {
+                        /*
+                         * no len: check only for device presence
+                         * This code is only called during device probe.
+                         */
                         rc = i2c_check_for_device(i2c_bus, addr);
-                        if (rc == -ENODEV) {
+                        if (rc == -ENXIO) {
                                 rt_mutex_unlock(&dev->i2c_bus_lock);
-                                return rc;
+                                return -ENODEV;
                         }
                 } else if (msgs[i].flags & I2C_M_RD) {
                         /* read bytes */