[U-Boot] [PATCH v3 1/2] i2c: mvtwsi: disable i2c slave on Armada 38x

[Stefan Roese]

On 06.06.2018 16:05, Baruch Siach wrote:
> Equivalent code that disables the hidden i2c0 slave already exists in
> the Turris Omnia platform specific code. But this hidden i2c0 slave that
> interferes the i2c bus is not board specific. Armada 38x SoCs and at
> least some Kirkwood variants are affected as well. Add code to disable
> this slave to the i2c bus driver to make it work on all affected
> hardware.
> 
> Use the bind callback because we want this to always run at boot,
> regardless of whether U-Boot uses the i2c bus.
> 
> Cc: Rabeeh Khoury <rabeeh at solid-run.com>
> Cc: Chris Packham <judge.packham at gmail.com>
> Reviewed-by: Stefan Roese <sr at denx.de>
> Reviewed-by: Heiko Schocher <hs at denx.de>
> Signed-off-by: Baruch Siach <baruch at tkos.co.il>
> ---
> v3:
>    * Fix build for SUNXI (Heiko Schocher)
> 
> v2:
>    * Use clrbits_le32 (Stefan Roese)
> 
>    * Apply to Kirkwood (Chris Packham)
> 
>    * Add review tags from Stefan and Heiko
> ---
>   drivers/i2c/mvtwsi.c | 25 ++++++++++++++++++++++++-
>   1 file changed, 24 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c
> index f9822e56b894..c4f387992b5d 100644
> --- a/drivers/i2c/mvtwsi.c
> +++ b/drivers/i2c/mvtwsi.c
> @@ -11,6 +11,7 @@
>   #include <i2c.h>
>   #include <linux/errno.h>
>   #include <asm/io.h>
> +#include <linux/bitops.h>
>   #include <linux/compat.h>
>   #ifdef CONFIG_DM_I2C
>   #include <dm.h>
> @@ -70,8 +71,10 @@ struct  mvtwsi_registers {
>   		u32 baudrate;	/* When writing */
>   	};
>   	u32 xtnd_slave_addr;
> -	u32 reserved[2];
> +	u32 reserved0[2];
>   	u32 soft_reset;
> +	u32 reserved1[27];
> +	u32 debug;
>   };
>   
>   #endif
> @@ -795,6 +798,25 @@ static int mvtwsi_i2c_ofdata_to_platdata(struct udevice *bus)
>   	return 0;
>   }
>   
> +static void twsi_disable_i2c_slave(struct mvtwsi_registers *twsi)
> +{
> +#if (defined(CONFIG_ARMADA_38X) || defined(CONFIG_KIRKWOOD))
> +	clrbits_le32(&twsi->debug, BIT(18));
> +#endif
> +}

I would prefer this version:

#if (defined(CONFIG_ARMADA_38X) || defined(CONFIG_KIRKWOOD))
static void twsi_disable_i2c_slave(struct mvtwsi_registers *twsi)
{
	clrbits_le32(&twsi->debug, BIT(18));
}
#else
static inline void twsi_disable_i2c_slave(struct mvtwsi_registers *twsi)
{
}
#endif

Thanks,
Stefan