i2c: ihs: Improve error handling

Improve the error handling and reporting of the IHS I2C driver.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Heiko Schocher <hs@denx.de>

diff --git a/drivers/i2c/ihs_i2c.c b/drivers/i2c/ihs_i2c.c
index 5313490bf3a0845cbaa8852b67bfd17e054bcad1..f7b59d36f983a8290cef2393ca847f597701f8a5 100644 (file)
--- a/drivers/i2c/ihs_i2c.c
+++ b/drivers/i2c/ihs_i2c.c
@@ -108,8 +108,10 @@ static int wait_for_int(bool read)
        while (!(val & (I2CINT_ERROR_EV
               | (read ? I2CINT_RECEIVE_EV : I2CINT_TRANSMIT_EV)))) {
                udelay(10);
-               if (ctr++ > 5000)
-                       return 1;
+               if (ctr++ > 5000) {
+                       debug("%s: timed out\n", __func__);
+                       return -ETIMEDOUT;
+               }
 #ifdef CONFIG_DM_I2C
                ihs_i2c_get(priv->map, interrupt_status, &val);
 #else
@@ -117,7 +119,7 @@ static int wait_for_int(bool read)
 #endif
        }
 
-       return (val & I2CINT_ERROR_EV) ? 1 : 0;
+       return (val & I2CINT_ERROR_EV) ? -EIO : 0;
 }
 
 #ifdef CONFIG_DM_I2C
@@ -130,6 +132,7 @@ static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
 {
        u16 val;
        u16 data;
+       int res;
 #ifdef CONFIG_DM_I2C
        struct ihs_i2c_priv *priv = dev_get_priv(dev);
 #endif
@@ -170,11 +173,16 @@ static int ihs_i2c_transfer(uchar chip, uchar *buffer, int len, bool read,
 #endif
 
 #ifdef CONFIG_DM_I2C
-       if (wait_for_int(dev, read))
+       res = wait_for_int(dev, read);
 #else
-       if (wait_for_int(read))
+       res = wait_for_int(read);
 #endif
-               return 1;
+       if (res) {
+               if (res == -ETIMEDOUT)
+                       debug("%s: time out while waiting for event\n", __func__);
+
+               return res;
+       }
 
        /* If we want to read, get the bytes from the mailbox */
        if (read) {
@@ -198,19 +206,21 @@ static int ihs_i2c_send_buffer(uchar chip, u8 *data, int len, bool hold_bus,
                               int read)
 #endif
 {
+       int res;
+
        while (len) {
                int transfer = min(len, 2);
                bool is_last = len <= transfer;
 
 #ifdef CONFIG_DM_I2C
-               if (ihs_i2c_transfer(dev, chip, data, transfer, read,
-                                    hold_bus ? false : is_last))
-                       return 1;
+               res = ihs_i2c_transfer(dev, chip, data, transfer, read,
+                                      hold_bus ? false : is_last);
 #else
-               if (ihs_i2c_transfer(chip, data, transfer, read,
-                                    hold_bus ? false : is_last))
-                       return 1;
+               res = ihs_i2c_transfer(chip, data, transfer, read,
+                                      hold_bus ? false : is_last);
 #endif
+               if (res)
+                       return res;
 
                data += transfer;
                len -= transfer;
@@ -241,14 +251,19 @@ static int ihs_i2c_access(struct i2c_adapter *adap, uchar chip, u8 *addr,
                          int alen, uchar *buffer, int len, int read)
 #endif
 {
+       int res;
+
        /* Don't hold the bus if length of data to send/receive is zero */
+       if (len <= 0)
+               return -EINVAL;
+
 #ifdef CONFIG_DM_I2C
-       if (len <= 0 || ihs_i2c_address(dev, chip, addr, alen, len))
-               return 1;
+       res = ihs_i2c_address(dev, chip, addr, alen, len);
 #else
-       if (len <= 0 || ihs_i2c_address(chip, addr, alen, len))
-               return 1;
+       res = ihs_i2c_address(chip, addr, alen, len);
 #endif
+       if (res)
+               return res;
 
 #ifdef CONFIG_DM_I2C
        return ihs_i2c_send_buffer(dev, chip, buffer, len, false, read);
@@ -273,7 +288,7 @@ static int ihs_i2c_set_bus_speed(struct udevice *bus, uint speed)
        struct ihs_i2c_priv *priv = dev_get_priv(bus);
 
        if (speed != priv->speed && priv->speed != 0)
-               return 1;
+               return -EINVAL;
 
        priv->speed = speed;
 
@@ -290,8 +305,8 @@ static int ihs_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
         * actucal data) or one message (just data)
         */
        if (nmsgs > 2 || nmsgs == 0) {
-               debug("%s: Only one or two messages are supported.", __func__);
-               return -1;
+               debug("%s: Only one or two messages are supported\n", __func__);
+               return -ENOTSUPP;
        }
 
        omsg = nmsgs == 1 ? &dummy : msg;
@@ -311,9 +326,11 @@ static int ihs_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
                              u32 chip_flags)
 {
        uchar buffer[2];
+       int res;
 
-       if (ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true))
-               return 1;
+       res = ihs_i2c_transfer(bus, chip_addr, buffer, 0, I2COP_READ, true);
+       if (res)
+               return res;
 
        return 0;
 }
@@ -355,9 +372,11 @@ static void ihs_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 static int ihs_i2c_probe(struct i2c_adapter *adap, uchar chip)
 {
        uchar buffer[2];
+       int res;
 
-       if (ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true))
-               return 1;
+       res = ihs_i2c_transfer(chip, buffer, 0, I2COP_READ, true);
+       if (res)
+               return res;
 
        return 0;
 }
@@ -388,7 +407,7 @@ static unsigned int ihs_i2c_set_bus_speed(struct i2c_adapter *adap,
                                          unsigned int speed)
 {
        if (speed != adap->speed)
-               return 1;
+               return -EINVAL;
        return speed;
 }