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| author | Antti Palosaari <crope@iki.fi> | 2012-04-02 20:18:59 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-04-09 14:53:30 -0300 |
| commit | ad30e91befd7153827a97faa8281dcd48aa6702d (patch) | |
| tree | a2074436e1b52588761ebd357b2e8942288a8d72 /drivers/media/dvb | |
| parent | 48bf7e1a9dce24adf79ea118ef001e781fb0e2e4 (diff) | |
| download | linux-ad30e91befd7153827a97faa8281dcd48aa6702d.tar.gz linux-ad30e91befd7153827a97faa8281dcd48aa6702d.tar.bz2 linux-ad30e91befd7153827a97faa8281dcd48aa6702d.zip | |
[media] af9035: fix and enhance I2C adapter
There was a bug I2C adapter writes and reads one byte too much.
As the most I2C clients has auto-increment register addressing
this leads next register from the target register overwritten by
garbage data.
As a change remove whole register address byte usage and write
data directly to the I2C bus without saying what are register
address bytes to firmware.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Cc: Michael Buesch <m@bues.ch>
Cc: Hans-Frieder Vogt <hfvogt@gmx.net>
Cc: Gianluca Gennari <gennarone@gmail.com>
Tested-by: Michael Buesch <m@bues.ch>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/dvb')
| -rw-r--r-- | drivers/media/dvb/dvb-usb/af9035.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/drivers/media/dvb/dvb-usb/af9035.c b/drivers/media/dvb/dvb-usb/af9035.c index 73044632d943..58fe69deda1f 100644 --- a/drivers/media/dvb/dvb-usb/af9035.c +++ b/drivers/media/dvb/dvb-usb/af9035.c @@ -224,6 +224,22 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, if (mutex_lock_interruptible(&d->i2c_mutex) < 0) return -EAGAIN; + /* + * I2C sub header is 5 bytes long. Meaning of those bytes are: + * 0: data len + * 1: I2C addr << 1 + * 2: reg addr len + * byte 3 and 4 can be used as reg addr + * 3: reg addr MSB + * used when reg addr len is set to 2 + * 4: reg addr LSB + * used when reg addr len is set to 1 or 2 + * + * For the simplify we do not use register addr at all. + * NOTE: As a firmware knows tuner type there is very small possibility + * there could be some tuner I2C hacks done by firmware and this may + * lead problems if firmware expects those bytes are used. + */ if (num == 2 && !(msg[0].flags & I2C_M_RD) && (msg[1].flags & I2C_M_RD)) { if (msg[0].len > 40 || msg[1].len > 40) { @@ -237,14 +253,15 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, msg[1].len); } else { /* I2C */ - u8 buf[4 + msg[0].len]; + u8 buf[5 + msg[0].len]; struct usb_req req = { CMD_I2C_RD, 0, sizeof(buf), buf, msg[1].len, msg[1].buf }; buf[0] = msg[1].len; buf[1] = msg[0].addr << 1; - buf[2] = 0x01; - buf[3] = 0x00; - memcpy(&buf[4], msg[0].buf, msg[0].len); + buf[2] = 0x00; /* reg addr len */ + buf[3] = 0x00; /* reg addr MSB */ + buf[4] = 0x00; /* reg addr LSB */ + memcpy(&buf[5], msg[0].buf, msg[0].len); ret = af9035_ctrl_msg(d->udev, &req); } } else if (num == 1 && !(msg[0].flags & I2C_M_RD)) { @@ -259,14 +276,15 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, msg[0].len - 3); } else { /* I2C */ - u8 buf[4 + msg[0].len]; + u8 buf[5 + msg[0].len]; struct usb_req req = { CMD_I2C_WR, 0, sizeof(buf), buf, 0, NULL }; buf[0] = msg[0].len; buf[1] = msg[0].addr << 1; - buf[2] = 0x01; - buf[3] = 0x00; - memcpy(&buf[4], msg[0].buf, msg[0].len); + buf[2] = 0x00; /* reg addr len */ + buf[3] = 0x00; /* reg addr MSB */ + buf[4] = 0x00; /* reg addr LSB */ + memcpy(&buf[5], msg[0].buf, msg[0].len); ret = af9035_ctrl_msg(d->udev, &req); } } else { |