[PATCH v2 1/8] ARM: at91: pm: rework cpu detection

Yang, Wenyou Wenyou.Yang at atmel.com
Thu Jan 15 18:44:39 PST 2015


Hi Alexandre,

> -----Original Message-----
> From: linux-arm-kernel [mailto:linux-arm-kernel-bounces at lists.infradead.org] On
> Behalf Of Alexandre Belloni
> Sent: Thursday, January 15, 2015 10:59 PM
> To: Ferre, Nicolas
> Cc: Boris Brezillon; Arnd Bergmann; linux-kernel at vger.kernel.org; Alexandre
> Belloni; Jean-Christophe Plagniol-Villard; linux-arm-kernel at lists.infradead.org
> Subject: [PATCH v2 1/8] ARM: at91: pm: rework cpu detection
> 
> Store SoC differences in a struct to remove cpu_is_* usage.
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
> ---
>  arch/arm/mach-at91/pm.c | 54 ++++++++++++++++++++++++++++++-----------------
> --
>  1 file changed, 33 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index
> 9b15169a1c62..79aa793d1f00 100644
> --- a/arch/arm/mach-at91/pm.c
> +++ b/arch/arm/mach-at91/pm.c
> @@ -17,6 +17,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/sysfs.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/io.h>
>  #include <linux/clk/at91_pmc.h>
> @@ -32,6 +33,11 @@
>  #include "generic.h"
>  #include "pm.h"
> 
> +static struct {
> +	unsigned long uhp_udp_mask;
> +	int memctrl;
> +} at91_pm_data;
> +
>  static void (*at91_pm_standby)(void);
> 
>  static int at91_pm_valid_state(suspend_state_t state) @@ -71,17 +77,9 @@ static
> int at91_pm_verify_clocks(void)
>  	scsr = at91_pmc_read(AT91_PMC_SCSR);
> 
>  	/* USB must not be using PLLB */
> -	if (cpu_is_at91rm9200()) {
> -		if ((scsr & (AT91RM9200_PMC_UHP |
> AT91RM9200_PMC_UDP)) != 0) {
> -			pr_err("AT91: PM - Suspend-to-RAM with USB still
> active\n");
> -			return 0;
> -		}
> -	} else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
> cpu_is_at91sam9263()
> -			|| cpu_is_at91sam9g20() || cpu_is_at91sam9g10()) {
> -		if ((scsr & (AT91SAM926x_PMC_UHP |
> AT91SAM926x_PMC_UDP)) != 0) {
> -			pr_err("AT91: PM - Suspend-to-RAM with USB still
> active\n");
> -			return 0;
> -		}
> +	if ((scsr & at91_pm_data.uhp_udp_mask) != 0) {
> +		pr_err("AT91: PM - Suspend-to-RAM with USB still active\n");
> +		return 0;
>  	}
> 
>  	/* PCK0..PCK3 must be disabled, or configured to use clk32k */ @@ -
> 149,18 +147,13 @@ static int at91_pm_enter(suspend_state_t state)
>  			 * turning off the main oscillator; reverse on wakeup.
>  			 */
>  			if (slow_clock) {
> -				int memctrl = AT91_MEMCTRL_SDRAMC;
> -
> -				if (cpu_is_at91rm9200())
> -					memctrl = AT91_MEMCTRL_MC;
> -				else if (cpu_is_at91sam9g45())
> -					memctrl = AT91_MEMCTRL_DDRSDR;
>  #ifdef CONFIG_AT91_SLOW_CLOCK
>  				/* copy slow_clock handler to SRAM, and call it */
>  				memcpy(slow_clock, at91_slow_clock,
> at91_slow_clock_sz);  #endif
>  				slow_clock(at91_pmc_base, at91_ramc_base[0],
> -					   at91_ramc_base[1], memctrl);
> +					   at91_ramc_base[1],
> +					   at91_pm_data.memctrl);
>  				break;
>  			} else {
>  				pr_info("AT91: PM - no slow clock mode
> enabled ...\n"); @@ -237,10 +230,29 @@ static int __init at91_pm_init(void)
> 
>  	pr_info("AT91: Power Management%s\n", (slow_clock ? " (with slow clock
> mode)" : ""));
> 
> -	/* AT91RM9200 SDRAM low-power mode cannot be used with self-refresh.
> */
> -	if (cpu_is_at91rm9200())
> +	at91_pm_data.memctrl = AT91_MEMCTRL_SDRAMC;
> +
> +	if (of_machine_is_compatible("atmel,at91rm9200")) {
> +		/*
> +		 * AT91RM9200 SDRAM low-power mode cannot be used with
> +		 * self-refresh.
> +		 */
>  		at91_ramc_write(0, AT91RM9200_SDRAMC_LPR, 0);
> -
> +
> +		at91_pm_data.uhp_udp_mask = AT91RM9200_PMC_UHP |
> +					    AT91RM9200_PMC_UDP;
> +		at91_pm_data.memctrl = AT91_MEMCTRL_MC;
> +	} else if (of_machine_is_compatible("atmel,at91sam9260") ||
> +		   of_machine_is_compatible("atmel,at91sam9g20") ||
> +		   of_machine_is_compatible("atmel,at91sam9261") ||
> +		   of_machine_is_compatible("atmel,at91sam9g10") ||
> +		   of_machine_is_compatible("atmel,at91sam9263")) {
> +		at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP |
> +					    AT91SAM926x_PMC_UDP;
> +	} else if (of_machine_is_compatible("atmel,at91sam9g45")) {
> +		at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
> +	}
> +
About the memory controller type, I prefer to get it during the memory controller initialization, from the sram_ids[].data which defined in the setup.c,
As this,
static const struct at91_ramc_of_data at91rm9200_ramc_of_data = {
	.ramc_type = AT91_MEMCTRL_MC,
};
...
static struct of_device_id ramc_ids[] = {
	{ .compatible = "atmel,at91rm9200-sdramc", .data = &at91rm9200_ramc_of_data},
	... ...
	{ /*sentinel*/ }
};

What about you? 

>  	if (at91_cpuidle_device.dev.platform_data)
>  		platform_device_register(&at91_cpuidle_device);
> 
> --
> 2.1.0
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Best Regards,
Wenyou Yang



More information about the linux-arm-kernel mailing list