V4L/DVB (12778): tm6000: Fix SMBus Read Byte command

Signed-off-by: Michel Ludwig <michel.ludwig@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/staging/tm6000/tm6000-i2c.c b/drivers/staging/tm6000/tm6000-i2c.c
index 5e165ed25eeedbf93d898e59121e30ab44034f9c..80252b74669996f16690c2185586b48ef1030625 100644 (file)
--- a/drivers/staging/tm6000/tm6000-i2c.c
+++ b/drivers/staging/tm6000/tm6000-i2c.c
@@ -3,6 +3,9 @@
 
    Copyright (C) 2006-2007 Mauro Carvalho Chehab <mchehab@infradead.org>
 
+   Copyright (C) 2007 Michel Ludwig <michel.ludwig@gmail.com>
+       - Fix SMBus Read Byte command
+
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation version 2
@@ -92,6 +95,7 @@ static int tm6000_i2c_xfer(struct i2c_adapter *i2c_adap,
 {
        struct tm6000_core *dev = i2c_adap->algo_data;
        int addr, rc, i, byte;
+       u8 prev_reg = 0;
 
        if (num <= 0)
                return 0;
@@ -100,25 +104,31 @@ static int tm6000_i2c_xfer(struct i2c_adapter *i2c_adap,
                i2c_dprintk(2,"%s %s addr=0x%x len=%d:",
                         (msgs[i].flags & I2C_M_RD) ? "read" : "write",
                         i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len);
-
                if (!msgs[i].len) {
                        /* Do I2C scan */
                        rc=tm6000_i2c_scan(i2c_adap, addr);
                } else if (msgs[i].flags & I2C_M_RD) {
-                       char buf[msgs[i].len];
-                       memcpy(buf,msgs[i].buf, msgs[i].len-1);
-                       buf[msgs[i].len-1]=0;
-
                        /* Read bytes */
        /* I2C is assumed to have always a subaddr at the first byte of the
           message bus. Also, the first i2c value of the answer is returned
           out of message data.
         */
-                       rc = tm6000_read_write_usb (dev,
-                               USB_DIR_IN | USB_TYPE_VENDOR,
-                               REQ_16_SET_GET_I2CSEQ,
-                               addr|(*msgs[i].buf)<<8, 0,
-                               msgs[i].buf, msgs[i].len);
+                       /* SMBus Read Byte command */
+                       if(msgs[i].len == 1) {
+                               // we use the previously used register to read from
+                               rc = tm6000_read_write_usb (dev,
+                                       USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+                                       REQ_16_SET_GET_I2CSEQ,
+                                       addr | prev_reg<<8, 0,
+                                       msgs[i].buf, msgs[i].len);
+                       }
+                       else {
+                               rc = tm6000_read_write_usb (dev,
+                                       USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+                                       REQ_16_SET_GET_I2CSEQ,
+                                       addr|(*msgs[i].buf)<<8, 0,
+                                       msgs[i].buf, msgs[i].len);
+                       }
                        if (i2c_debug>=2) {
                                for (byte = 0; byte < msgs[i].len; byte++) {
                                        printk(" %02x", msgs[i].buf[byte]);
@@ -136,6 +146,13 @@ static int tm6000_i2c_xfer(struct i2c_adapter *i2c_adap,
                                REQ_16_SET_GET_I2CSEQ,
                                addr|(*msgs[i].buf)<<8, 0,
                                msgs[i].buf+1, msgs[i].len-1);
+
+                       if(msgs[i].len >= 1) {
+                               prev_reg = msgs[i].buf[0];
+                       }
+                       else {
+                               prev_reg = 0;
+                       }
                }
                if (i2c_debug>=2)
                        printk("\n");