[U-Boot,u-boot] ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel

If board is booted with transitions happening on DCAN1 pins then
the following warning is seen in the kernel at boot when the
hwmod layer initializes.

"omap_hwmod: dcan1: _wait_target_disable failed"

This is because DCAN1 module's SWAKEUP mechanism is broken
and it fails to correctly turn OFF if it sees a transition on the
DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode
while enabling/disabling DCAN1 module.

The hwmod layer enables and disables all modules at boot
and we have no opportunity to put the DCAN1 pins in safe mode
at that point.

DCAN1 is not used by u-boot so it doesn't matter to it if these
pins are in safe mode. The kernel driver correctly configures
the right mode when DCAN1 is active.

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 board/ti/dra7xx/mux_data.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

On 06/24/2015 09:00 AM, Roger Quadros wrote:
> If board is booted with transitions happening on DCAN1 pins then
> the following warning is seen in the kernel at boot when the
> hwmod layer initializes.
> 
> "omap_hwmod: dcan1: _wait_target_disable failed"
> 
> This is because DCAN1 module's SWAKEUP mechanism is broken
> and it fails to correctly turn OFF if it sees a transition on the
> DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode
> while enabling/disabling DCAN1 module.
> 
> The hwmod layer enables and disables all modules at boot
> and we have no opportunity to put the DCAN1 pins in safe mode
> at that point.
> 
> DCAN1 is not used by u-boot so it doesn't matter to it if these
> pins are in safe mode. The kernel driver correctly configures
> the right mode when DCAN1 is active.
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
>  board/ti/dra7xx/mux_data.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/board/ti/dra7xx/mux_data.h b/board/ti/dra7xx/mux_data.h
> index c9301a5..91e00b9 100644
> --- a/board/ti/dra7xx/mux_data.h
> +++ b/board/ti/dra7xx/mux_data.h
> @@ -358,7 +358,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
>  	{SPI2_D1, (M1 | PIN_INPUT_SLEW)},	/* spi2_d1.uart3_txd */
>  	{SPI2_D0, (M1 | PIN_INPUT_SLEW)},	/* spi2_d0.uart3_ctsn */
>  	{SPI2_CS0, (M1 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* spi2_cs0.uart3_rtsn */
> -	{DCAN1_TX, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_tx.dcan1_tx */
> +	{DCAN1_TX, (M15 | PULL_UP)},	/* dcan1_tx.safe for dcan1_tx */
>  	{DCAN1_RX, (M14 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* dcan1_rx.gpio1_15 */
>  	{UART1_RXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_rxd.uart1_rxd */
>  	{UART1_TXD, (M0 | PIN_INPUT_PULLUP | SLEWCONTROL)},	/* uart1_txd.uart1_txd */
> @@ -370,7 +370,7 @@ const struct pad_conf_entry dra74x_core_padconf_array[] = {
>  	{UART2_RTSN, (M3 | PIN_INPUT_PULLUP)},	/* uart2_rtsn.mmc4_dat3 */
>  	{I2C2_SDA, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_sda.i2c2_sda */
>  	{I2C2_SCL, (M0 | PIN_INPUT_PULLUP)},	/* i2c2_scl.i2c2_scl */
> -	{WAKEUP0, (M1 | PIN_OUTPUT)},	/* Wakeup0.dcan1_rx */
> +	{WAKEUP0, (M15 | PULL_UP)},	/* Wakeup0.safe for dcan1_rx */
>  	{WAKEUP2, (M14 | PIN_OUTPUT)},	/* Wakeup2.gpio1_2 */
>  };
>  
> 
LGTM, could you also look at x15 platform?

On Wed, Jun 24, 2015 at 05:00:11PM +0300, Roger Quadros wrote:

> If board is booted with transitions happening on DCAN1 pins then
> the following warning is seen in the kernel at boot when the
> hwmod layer initializes.
> 
> "omap_hwmod: dcan1: _wait_target_disable failed"
> 
> This is because DCAN1 module's SWAKEUP mechanism is broken
> and it fails to correctly turn OFF if it sees a transition on the
> DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode
> while enabling/disabling DCAN1 module.
> 
> The hwmod layer enables and disables all modules at boot
> and we have no opportunity to put the DCAN1 pins in safe mode
> at that point.
> 
> DCAN1 is not used by u-boot so it doesn't matter to it if these
> pins are in safe mode. The kernel driver correctly configures
> the right mode when DCAN1 is active.
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>

Applied to u-boot/master, thanks!