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author | Chris Pascoe <c.pascoe@itee.uq.edu.au> | 2007-12-15 03:31:09 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-01-25 19:04:03 -0200 |
commit | 5e3c5967da48b54e5d4ee528b51b565e2f7a3178 (patch) | |
tree | 8adc130fdbc521c9b383f63f70f78757b57e70c0 /drivers/media/video/cx23885 | |
parent | bc514710889ebb975be9e84ca9c04f698225b656 (diff) | |
download | op-kernel-dev-5e3c5967da48b54e5d4ee528b51b565e2f7a3178.zip op-kernel-dev-5e3c5967da48b54e5d4ee528b51b565e2f7a3178.tar.gz |
V4L/DVB (6857): cx23885: correctly join I2C writes and reads from same address
When an I2C message specifies a write then a read from the same I2C address,
we need to tell the chip to not release the bus between the message parts.
Signed-off-by: Chris Pascoe <c.pascoe@itee.uq.edu.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media/video/cx23885')
-rw-r--r-- | drivers/media/video/cx23885/cx23885-i2c.c | 53 |
1 files changed, 39 insertions, 14 deletions
diff --git a/drivers/media/video/cx23885/cx23885-i2c.c b/drivers/media/video/cx23885/cx23885-i2c.c index 08e92df..20f3fb4 100644 --- a/drivers/media/video/cx23885/cx23885-i2c.c +++ b/drivers/media/video/cx23885/cx23885-i2c.c @@ -37,8 +37,10 @@ static unsigned int i2c_scan = 0; module_param(i2c_scan, int, 0444); MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); -#define dprintk(level,fmt, arg...) if (i2c_debug >= level) \ - printk(KERN_DEBUG "%s: " fmt, dev->name , ## arg) +#define dprintk(level, fmt, arg...) do { \ + if (i2c_debug >= level) \ + printk(KERN_DEBUG "%s: " fmt, dev->name , ## arg); \ + } while (0) #define I2C_WAIT_DELAY 32 #define I2C_WAIT_RETRY 64 @@ -77,14 +79,18 @@ static int i2c_wait_done(struct i2c_adapter *i2c_adap) } static int i2c_sendbytes(struct i2c_adapter *i2c_adap, - const struct i2c_msg *msg, int last) + const struct i2c_msg *msg, int joined_rlen) { struct cx23885_i2c *bus = i2c_adap->algo_data; struct cx23885_dev *dev = bus->dev; u32 wdata, addr, ctrl; int retval, cnt; - dprintk(1, "%s(msg->len=%d, last=%d)\n", __FUNCTION__, msg->len, last); + if (joined_rlen) + dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __FUNCTION__, + msg->len, joined_rlen); + else + dprintk(1, "%s(msg->len=%d)\n", __FUNCTION__, msg->len); /* Deal with i2c probe functions with zero payload */ if (msg->len == 0) { @@ -107,6 +113,8 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap, if (msg->len > 1) ctrl |= I2C_NOSTOP | I2C_EXTEND; + else if (joined_rlen) + ctrl |= I2C_NOSTOP; cx_write(bus->reg_addr, addr); cx_write(bus->reg_wdata, wdata); @@ -130,6 +138,8 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap, if (cnt < msg->len - 1) ctrl |= I2C_NOSTOP | I2C_EXTEND; + else if (joined_rlen) + ctrl |= I2C_NOSTOP; cx_write(bus->reg_addr, addr); cx_write(bus->reg_wdata, wdata); @@ -151,19 +161,22 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap, eio: retval = -EIO; err: - printk(" ERR: %d\n", retval); + if (i2c_debug) + printk(" ERR: %d\n", retval); return retval; } static int i2c_readbytes(struct i2c_adapter *i2c_adap, - const struct i2c_msg *msg, int last) + const struct i2c_msg *msg, int joined) { struct cx23885_i2c *bus = i2c_adap->algo_data; struct cx23885_dev *dev = bus->dev; u32 ctrl, cnt; int retval; - dprintk(1, "%s(msg->len=%d, last=%d)\n", __FUNCTION__, msg->len, last); + + if (i2c_debug && !joined) + dprintk(1, "%s(msg->len=%d)\n", __FUNCTION__, msg->len); /* Deal with i2c probe functions with zero payload */ if (msg->len == 0) { @@ -179,8 +192,12 @@ static int i2c_readbytes(struct i2c_adapter *i2c_adap, return 0; } - if (i2c_debug) - printk(" <R %02x", (msg->addr << 1) + 1); + if (i2c_debug) { + if (joined) + printk(" R"); + else + printk(" <R %02x", (msg->addr << 1) + 1); + } for(cnt = 0; cnt < msg->len; cnt++) { @@ -209,7 +226,8 @@ static int i2c_readbytes(struct i2c_adapter *i2c_adap, eio: retval = -EIO; err: - printk(" ERR: %d\n", retval); + if (i2c_debug) + printk(" ERR: %d\n", retval); return retval; } @@ -227,15 +245,22 @@ static int i2c_xfer(struct i2c_adapter *i2c_adap, __FUNCTION__, num, msgs[i].addr, msgs[i].len); if (msgs[i].flags & I2C_M_RD) { /* read */ - retval = i2c_readbytes(i2c_adap, &msgs[i], i+1 == num); + retval = i2c_readbytes(i2c_adap, &msgs[i], 0); + } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && + msgs[i].addr == msgs[i + 1].addr) { + /* write then read from same address */ + retval = i2c_sendbytes(i2c_adap, &msgs[i], + msgs[i + 1].len); if (retval < 0) goto err; + i++; + retval = i2c_readbytes(i2c_adap, &msgs[i], 1); } else { /* write */ - retval = i2c_sendbytes(i2c_adap, &msgs[i], i+1 == num); - if (retval < 0) - goto err; + retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); } + if (retval < 0) + goto err; } return num; |