On Wed, Feb 02, 2011 at 10:23:42PM +0100, Matej Kupljen wrote:
> 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 <[email protected]>
> 
> --- 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)

bool 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))) {

no need for () around !repeated.

>               /* 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;

see above.

>       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))

no need for () around i > 0

> +                     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);
  

-- 
Ben Dooks, [email protected], http://www.fluff.org/ben/

Large Hadron Colada: A large Pina Colada that makes the universe disappear.

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