Kevin,
> Thanks for posting this patch. See comments below..
> I'll be happy to test your changes once the following items
> are clarified.
>
> > The pathch is against 2.6.28.2, but it should apply to the
> > cureent GIT version as well.
>
> This patch needs to be re-based against the latest version
> of the driver as it has changes that this patch will revert
> or won't apply to.
I re-based it against latest version of the kernel in GIT and
also included your comments in the mail.
Is it O.K. now?
Regards,
Matej
P.S.: Changed the email client. I now attached the file as
well as pasted it in-line.
-------------------------------------------------------------------
Current code in i2c-pnx.c doesn't support sending messages
with restart condition in it, for example:
S - (address | W) - Sr - (address | R) - ... - P
This patch adds this to the current code. It has been
tested on a custom board with LPC3152 CPU (similar to
Embedded Artists EA313x board) with uBlox GPS receiver
connected to I2C bus. It has been running over the night
without errors.
Signed-off-by: Matej Kupljen <matej.kupljen@xxxxxxxxx>
--- i2c-pnx-orig.c 2011-02-02 21:30:19.000000000 +0100
+++ i2c-pnx.c 2011-02-02 21:49:02.000000000 +0100
@@ -78,7 +78,7 @@
* Generate a START signal in the desired mode.
*/
static int i2c_pnx_start(unsigned char slave_addr,
- struct i2c_pnx_algo_data *alg_data)
+ struct i2c_pnx_algo_data *alg_data, int repeated)
{
dev_dbg(&alg_data->adapter.dev, "%s(): addr 0x%x mode %d\n", __func__,
slave_addr, alg_data->mif.mode);
@@ -91,8 +91,8 @@
return -EINVAL;
}
- /* First, make sure bus is idle */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
+ /* First, make sure bus is idle, if we are not doing repeated start */
+ if ((!repeated) && (wait_timeout(I2C_PNX_TIMEOUT, alg_data))) {
/* Somebody else is monopolizing the bus */
dev_err(&alg_data->adapter.dev,
"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
@@ -441,7 +441,7 @@
i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct i2c_msg *pmsg;
- int rc = 0, completed = 0, i;
+ int rc = 0, completed = 0, i, repeated;
struct i2c_pnx_algo_data *alg_data = adap->algo_data;
u32 stat = ioread32(I2C_REG_STS(alg_data));
@@ -457,6 +457,7 @@
pmsg = &msgs[i];
addr = pmsg->addr;
+ repeated = 0;
if (pmsg->flags & I2C_M_TEN) {
dev_err(&alg_data->adapter.dev,
@@ -481,16 +482,23 @@
/* initialize the completion var */
init_completion(&alg_data->mif.complete);
- /* Enable master interrupt */
- iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
- mcntrl_naie | mcntrl_drmie,
- I2C_REG_CTL(alg_data));
+ /*
+ * If this is not the only message, then we need to
+ * send repeated start, but only if the flag allows it
+ */
+ if((i > 0) && !(pmsg->flags & I2C_M_NOSTART))
+ repeated = 1;
/* Put start-code and slave-address on the bus. */
- rc = i2c_pnx_start(addr, alg_data);
+ rc = i2c_pnx_start(addr, alg_data, repeated);
if (rc < 0)
break;
+ /* Enable master interrupt */
+ iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
+ mcntrl_naie | mcntrl_drmie,
+ I2C_REG_CTL(alg_data));
+
/* Wait for completion */
wait_for_completion(&alg_data->mif.complete);
Current code in i2c-pnx.c doesn't support sending messages
with restart condition in it, for example:
S - (address | W) - Sr - (address | R) - ... - P
This patch adds this to the current code. It has been
tested on a custom board with LPC3152 CPU (similar to
Embedded Artists EA313x board) with uBlox GPS receiver
connected to I2C bus. It has been running over the night
without errors.
Signed-off-by: Matej Kupljen <matej.kupljen@xxxxxxxxx>
--- i2c-pnx-orig.c 2011-02-02 21:30:19.000000000 +0100
+++ i2c-pnx.c 2011-02-02 21:49:02.000000000 +0100
@@ -78,7 +78,7 @@
* Generate a START signal in the desired mode.
*/
static int i2c_pnx_start(unsigned char slave_addr,
- struct i2c_pnx_algo_data *alg_data)
+ struct i2c_pnx_algo_data *alg_data, int repeated)
{
dev_dbg(&alg_data->adapter.dev, "%s(): addr 0x%x mode %d\n", __func__,
slave_addr, alg_data->mif.mode);
@@ -91,8 +91,8 @@
return -EINVAL;
}
- /* First, make sure bus is idle */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
+ /* First, make sure bus is idle, if we are not doing repeated start */
+ if ((!repeated) && (wait_timeout(I2C_PNX_TIMEOUT, alg_data))) {
/* Somebody else is monopolizing the bus */
dev_err(&alg_data->adapter.dev,
"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
@@ -441,7 +441,7 @@
i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct i2c_msg *pmsg;
- int rc = 0, completed = 0, i;
+ int rc = 0, completed = 0, i, repeated;
struct i2c_pnx_algo_data *alg_data = adap->algo_data;
u32 stat = ioread32(I2C_REG_STS(alg_data));
@@ -457,6 +457,7 @@
pmsg = &msgs[i];
addr = pmsg->addr;
+ repeated = 0;
if (pmsg->flags & I2C_M_TEN) {
dev_err(&alg_data->adapter.dev,
@@ -481,16 +482,23 @@
/* initialize the completion var */
init_completion(&alg_data->mif.complete);
- /* Enable master interrupt */
- iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
- mcntrl_naie | mcntrl_drmie,
- I2C_REG_CTL(alg_data));
+ /*
+ * If this is not the only message, then we need to
+ * send repeated start, but only if the flag allows it
+ */
+ if((i > 0) && !(pmsg->flags & I2C_M_NOSTART))
+ repeated = 1;
/* Put start-code and slave-address on the bus. */
- rc = i2c_pnx_start(addr, alg_data);
+ rc = i2c_pnx_start(addr, alg_data, repeated);
if (rc < 0)
break;
+ /* Enable master interrupt */
+ iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
+ mcntrl_naie | mcntrl_drmie,
+ I2C_REG_CTL(alg_data));
+
/* Wait for completion */
wait_for_completion(&alg_data->mif.complete);
