Subject: [PATCHv3 2/6] ARM: OMAP3 PM: Move IO Daisychain function to omap3 prm file

From: [email-masked] (Rajendra Nayak)
Date: Thu, 01 Mar 2012 12:19:33 +0530

On Wednesday 29 February 2012 07:56 PM, Tero Kristo wrote:
> From: Vishwanath BS<[email-masked]>
>
> Since IO Daisychain modifies only PRM registers, it makes sense to move
> it to PRM File.
>
> Signed-off-by: Vishwanath BS<[email-masked]>
> Tested-by: Govindraj.R<[email-masked]>
> Signed-off-by: Tero Kristo<[email-masked]>
> ---
>   arch/arm/mach-omap2/pm34xx.c       |   30 +-----------------------------
>   arch/arm/mach-omap2/prm2xxx_3xxx.c |   32 ++++++++++++++++++++++++++++++++
>   arch/arm/mach-omap2/prm2xxx_3xxx.h |   14 ++++++++++++++
>   3 files changed, 47 insertions(+), 29 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
> index b0821a8..e97ec3f 100644
> --- a/arch/arm/mach-omap2/pm34xx.c
> +++ b/arch/arm/mach-omap2/pm34xx.c
> @@ -85,34 +85,6 @@ static inline void omap3_per_restore_context(void)
>   	omap_gpio_restore_context();
>   }
>
> -static void omap3_enable_io_chain(void)
> -{
> -	int timeout = 0;
> -
> -	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> -				   PM_WKEN);
> -	/* Do a readback to assure write has been done */
> -	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
> -
> -	while (!(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
> -		 OMAP3430_ST_IO_CHAIN_MASK)) {
> -		timeout++;
> -		if (timeout>  1000) {
> -			pr_err("Wake up daisy chain activation failed.\n");
> -			return;
> -		}
> -	}
> -	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> -			PM_WKEN);
> -
> -}
> -
> -static void omap3_disable_io_chain(void)
> -{
> -	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> -				     PM_WKEN);
> -}
> -
>   static void omap3_core_save_context(void)
>   {
>   	omap3_ctrl_save_padconf();
> @@ -324,7 +296,7 @@ void omap_sram_idle(void)
>   	     core_next_state<  PWRDM_POWER_ON)) {
>   		omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD, PM_WKEN);
>   		if (omap3_has_io_chain_ctrl())
> -			omap3_enable_io_chain();
> +			omap3_trigger_io_chain();
>   	}
>
>   	pwrdm_pre_transition();
> diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c
> index 9ce7654..fc98781 100644
> --- a/arch/arm/mach-omap2/prm2xxx_3xxx.c
> +++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c
> @@ -301,6 +301,38 @@ void omap3xxx_prm_restore_irqen(u32 *saved_mask)
>   				OMAP3_PRM_IRQENABLE_MPU_OFFSET);
>   }
>
> +/**
> + * Maximum time(us) it takes to output the signal WUCLKOUT of the last pad of
> + * the I/O ring after asserting WUCLKIN high
> + */
> +#define MAX_IOPAD_LATCH_TIME 1000

Since we are changing the implementation to use omap_test_timeout()
in this patch, it makes sense to make this 100 so we have a max 100us
delay, similar to what we did on OMAP4.

> +
> +/* OMAP3 Daisychain enable sequence */
> +void omap3_trigger_io_chain(void)
> +{
> +	int i = 0;
> +
> +	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> +				   PM_WKEN);
> +	/* Do a readback to assure write has been done */
> +	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKEN);
> +
> +	omap_test_timeout(((omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST)&
> +			    OMAP3430_ST_IO_CHAIN_MASK) == 1),
> +			  MAX_IOPAD_LATCH_TIME, i);
> +
> +	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
> +				     PM_WKEN);

The comment from Djamil should hold good here too. We should wait for
IO chain status to show 0 here.

> +}
> +

regards,
Rajendra