[media] hdpvr: i2c master enhancements

Make the hdpvr's i2c master implementation more closely mirror that of
the pvrusb2 driver. Currently makes no significant difference in IR
reception behavior with ir-kbd-i2c (i.e., it still sucks).

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/hdpvr/hdpvr-i2c.c b/drivers/media/video/hdpvr/hdpvr-i2c.c
index e53fa55..3e06587 100644 (file)
--- a/drivers/media/video/hdpvr/hdpvr-i2c.c
+++ b/drivers/media/video/hdpvr/hdpvr-i2c.c
@@ -62,15 +62,25 @@ struct i2c_client *hdpvr_register_ir_rx_i2c(struct hdpvr_device *dev)
 }
 
 static int hdpvr_i2c_read(struct hdpvr_device *dev, int bus,
-                         unsigned char addr, char *data, int len)
+                         unsigned char addr, char *wdata, int wlen,
+                         char *data, int len)
 {
        int ret;
 
-       if (len > sizeof(dev->i2c_buf))
+       if ((len > sizeof(dev->i2c_buf)) || (wlen > sizeof(dev->i2c_buf)))
                return -EINVAL;
 
-       ret = usb_control_msg(dev->udev,
-                             usb_rcvctrlpipe(dev->udev, 0),
+       if (wlen) {
+               memcpy(&dev->i2c_buf, wdata, wlen);
+               ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
+                                     REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
+                                     (bus << 8) | addr, 0, &dev->i2c_buf,
+                                     wlen, 1000);
+               if (ret < 0)
+                       return ret;
+       }
+
+       ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_READ, CTRL_READ_REQUEST,
                              (bus << 8) | addr, 0, &dev->i2c_buf, len, 1000);
 
@@ -92,16 +102,14 @@ static int hdpvr_i2c_write(struct hdpvr_device *dev, int bus,
                return -EINVAL;
 
        memcpy(&dev->i2c_buf, data, len);
-       ret = usb_control_msg(dev->udev,
-                             usb_sndctrlpipe(dev->udev, 0),
+       ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
                              (bus << 8) | addr, 0, &dev->i2c_buf, len, 1000);
 
        if (ret < 0)
                return ret;
 
-       ret = usb_control_msg(dev->udev,
-                             usb_rcvctrlpipe(dev->udev, 0),
+       ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_WRITE_STATT, CTRL_READ_REQUEST,
                              0, 0, &dev->i2c_buf, 2, 1000);
 
@@ -117,24 +125,49 @@ static int hdpvr_transfer(struct i2c_adapter *i2c_adapter, struct i2c_msg *msgs,
                          int num)
 {
        struct hdpvr_device *dev = i2c_get_adapdata(i2c_adapter);
-       int retval = 0, i, addr;
+       int retval = 0, addr;
 
        if (num <= 0)
                return 0;
 
        mutex_lock(&dev->i2c_mutex);
 
-       for (i = 0; i < num && !retval; i++) {
-               addr = msgs[i].addr << 1;
+       addr = msgs[0].addr << 1;
 
-               if (msgs[i].flags & I2C_M_RD)
-                       retval = hdpvr_i2c_read(dev, 1, addr, msgs[i].buf,
-                                               msgs[i].len);
+       if (num == 1) {
+               if (msgs[0].flags & I2C_M_RD)
+                       retval = hdpvr_i2c_read(dev, 1, addr, NULL, 0,
+                                               msgs[0].buf, msgs[0].len);
                else
-                       retval = hdpvr_i2c_write(dev, 1, addr, msgs[i].buf,
-                                                msgs[i].len);
+                       retval = hdpvr_i2c_write(dev, 1, addr, msgs[0].buf,
+                                                msgs[0].len);
+       } else if (num == 2) {
+               if (msgs[0].addr != msgs[1].addr) {
+                       v4l2_warn(&dev->v4l2_dev, "refusing 2-phase i2c xfer "
+                                 "with conflicting target addresses\n");
+                       retval = -EINVAL;
+                       goto out;
+               }
+
+               if ((msgs[0].flags & I2C_M_RD) || !(msgs[1].flags & I2C_M_RD)) {
+                       v4l2_warn(&dev->v4l2_dev, "refusing complex xfer with "
+                                 "r0=%d, r1=%d\n", msgs[0].flags & I2C_M_RD,
+                                 msgs[1].flags & I2C_M_RD);
+                       retval = -EINVAL;
+                       goto out;
+               }
+
+               /*
+                * Write followed by atomic read is the only complex xfer that
+                * we actually support here.
+                */
+               retval = hdpvr_i2c_read(dev, 1, addr, msgs[0].buf, msgs[0].len,
+                                       msgs[1].buf, msgs[1].len);
+       } else {
+               v4l2_warn(&dev->v4l2_dev, "refusing %d-phase i2c xfer\n", num);
        }
 
+out:
        mutex_unlock(&dev->i2c_mutex);
 
        return retval ? retval : num;
@@ -162,7 +195,7 @@ static int hdpvr_activate_ir(struct hdpvr_device *dev)
 
        mutex_lock(&dev->i2c_mutex);
 
-       hdpvr_i2c_read(dev, 0, 0x54, buffer, 1);
+       hdpvr_i2c_read(dev, 0, 0x54, NULL, 0, buffer, 1);
 
        buffer[0] = 0;
        buffer[1] = 0x8;