Re: [PATCH] OMAP3: GPIO: Enable debounce clock only when debounce is enabled

[Kevin Hilman <khilman@deeprootsystems.com>]

Jouni Hogander <jouni.hogander@nokia.com> writes:

> This patch changes gpio "driver" to enable debounce clock for
> gpio-bank only when debounce is enabled for some gpio in that bank.
>
> Gpio functional clocks are also renamed in clock tree, gpioX_fck ->
> gpioX_dbck.
>
> This patch triggers problem with gpio wake-up and Omap3. Gpios in PER
> domain aren't capable to generate wake-up if PER domain is in sleep
> state. For this iopad wake-up should be used and needed pad
> configuration should be done. Enabling iopad wake-up for gpio pads is
> left for bootloader or omap mux configuration in kernel.
>
> Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
> ---
>  arch/arm/mach-omap2/clock34xx.h |   36 ++++++++++++++++++------------------
>  arch/arm/plat-omap/gpio.c       |   26 +++++++++++++++++---------
>  2 files changed, 35 insertions(+), 27 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/clock34xx.h b/arch/arm/mach-omap2/clock34xx.h
> index 674c204..1ba4ea9 100644
> --- a/arch/arm/mach-omap2/clock34xx.h
> +++ b/arch/arm/mach-omap2/clock34xx.h
> @@ -2335,8 +2335,8 @@ static struct clk wkup_32k_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio1_fck = {
> -	.name		= "gpio1_fck",
> +static struct clk gpio1_dbck = {
> +	.name		= "gpio1_dbck",
>  	.parent		= &wkup_32k_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(WKUP_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO1_SHIFT,
> @@ -2582,8 +2582,8 @@ static struct clk per_32k_alwon_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio6_fck = {
> -	.name		= "gpio6_fck",
> +static struct clk gpio6_dbck = {
> +	.name		= "gpio6_dbck",
>  	.parent		= &per_32k_alwon_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(OMAP3430_PER_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO6_SHIFT,
> @@ -2592,8 +2592,8 @@ static struct clk gpio6_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio5_fck = {
> -	.name		= "gpio5_fck",
> +static struct clk gpio5_dbck = {
> +	.name		= "gpio5_dbck",
>  	.parent		= &per_32k_alwon_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(OMAP3430_PER_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO5_SHIFT,
> @@ -2602,8 +2602,8 @@ static struct clk gpio5_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio4_fck = {
> -	.name		= "gpio4_fck",
> +static struct clk gpio4_dbck = {
> +	.name		= "gpio4_dbck",
>  	.parent		= &per_32k_alwon_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(OMAP3430_PER_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO4_SHIFT,
> @@ -2612,8 +2612,8 @@ static struct clk gpio4_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio3_fck = {
> -	.name		= "gpio3_fck",
> +static struct clk gpio3_dbck = {
> +	.name		= "gpio3_dbck",
>  	.parent		= &per_32k_alwon_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(OMAP3430_PER_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO3_SHIFT,
> @@ -2622,8 +2622,8 @@ static struct clk gpio3_fck = {
>  	.recalc		= &followparent_recalc,
>  };
>  
> -static struct clk gpio2_fck = {
> -	.name		= "gpio2_fck",
> +static struct clk gpio2_dbck = {
> +	.name		= "gpio2_dbck",
>  	.parent		= &per_32k_alwon_fck,
>  	.enable_reg	= _OMAP34XX_CM_REGADDR(OMAP3430_PER_MOD, CM_FCLKEN),
>  	.enable_bit	= OMAP3430_EN_GPIO2_SHIFT,
> @@ -3225,7 +3225,7 @@ static struct clk *onchip_34xx_clks[] __initdata = {
>  	&usim_fck,
>  	&gpt1_fck,
>  	&wkup_32k_fck,
> -	&gpio1_fck,
> +	&gpio1_dbck,
>  	&wdt2_fck,
>  	&wkup_l4_ick,
>  	&usim_ick,
> @@ -3247,11 +3247,11 @@ static struct clk *onchip_34xx_clks[] __initdata = {
>  	&gpt8_fck,
>  	&gpt9_fck,
>  	&per_32k_alwon_fck,
> -	&gpio6_fck,
> -	&gpio5_fck,
> -	&gpio4_fck,
> -	&gpio3_fck,
> -	&gpio2_fck,
> +	&gpio6_dbck,
> +	&gpio5_dbck,
> +	&gpio4_dbck,
> +	&gpio3_dbck,
> +	&gpio2_dbck,
>  	&wdt3_fck,
>  	&per_l4_ick,
>  	&gpio6_ick,
> diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c
> index ac55616..b4817b5 100644
> --- a/arch/arm/plat-omap/gpio.c
> +++ b/arch/arm/plat-omap/gpio.c
> @@ -151,6 +151,9 @@ struct gpio_bank {
>  	u32 level_mask;
>  	spinlock_t lock;
>  	struct gpio_chip chip;
> +#if defined(CONFIG_ARCH_OMAP3)
> +	struct clk *dbck;
> +#endif
>  };
>  
>  #define METHOD_MPUIO		0
> @@ -483,11 +486,16 @@ void omap_set_gpio_debounce(int gpio, int enable)
>  	reg += OMAP24XX_GPIO_DEBOUNCE_EN;
>  	val = __raw_readl(reg);
>  
> -	if (enable)
> +	if (enable && !(val & l))
>  		val |= l;
> -	else
> +	else if (!enable && val & l)
>  		val &= ~l;
> +	else
> +		return;
>  
> +#if defined(CONFIG_ARCH_OMAP3)
> +	enable ? clk_enable(bank->dbck) : clk_disable(bank->dbck);
> +#endif

For proper multi-omap support, you also need an 'if  cpu_is_34xx()' here

>  	__raw_writel(val, reg);
>  }
>  EXPORT_SYMBOL(omap_set_gpio_debounce);
> @@ -1298,7 +1306,6 @@ static struct clk * gpio5_fck;
>  #endif
>  
>  #if defined(CONFIG_ARCH_OMAP3)
> -static struct clk *gpio_fclks[OMAP34XX_NR_GPIOS];
>  static struct clk *gpio_iclks[OMAP34XX_NR_GPIOS];
>  #endif
>  
> @@ -1369,12 +1376,6 @@ static int __init _omap_gpio_init(void)
>  				printk(KERN_ERR "Could not get %s\n", clk_name);
>  			else
>  				clk_enable(gpio_iclks[i]);
> -			sprintf(clk_name, "gpio%d_fck", i + 1);
> -			gpio_fclks[i] = clk_get(NULL, clk_name);
> -			if (IS_ERR(gpio_fclks[i]))
> -				printk(KERN_ERR "Could not get %s\n", clk_name);
> -			else
> -				clk_enable(gpio_fclks[i]);
>  		}
>  	}
>  #endif
> @@ -1513,6 +1514,13 @@ static int __init _omap_gpio_init(void)
>  		}
>  		set_irq_chained_handler(bank->irq, gpio_irq_handler);
>  		set_irq_data(bank->irq, bank);
> +
> +#if defined(CONFIG_ARCH_OMAP3)
> +		sprintf(clk_name, "gpio%d_dbck", i + 1);
> +		bank->dbck = clk_get(NULL, clk_name);
> +		if (IS_ERR(bank->dbck))
> +			printk(KERN_ERR "Could not get %s\n", clk_name);
> +#endif

And here.

Or, since this is init code and not performance critical, it may be a
bit cleaner to just get rid of the #ifdef and use the runtime
checking.

Kevin

>  	}
>  
>  	/* Enable system clock for GPIO module.
> -- 
> 1.5.5
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html