[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>

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index 342f35a..76f9566 100644 (file)
--- 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 */