Re: [PATCH 1/6] ARM: at91: pm: rework cpu detection

From: Jean-Christophe PLAGNIOL-VILLARD
Date: Wed Jan 14 2015 - 14:37:38 EST


On 22:23 Mon 12 Jan , Alexandre Belloni wrote:
> Store SoC differences in a struct to remove cpu_is_* usage.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
> ---
> 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")) {
nack here

you switch for runtime information from the SOC register store in ram to DT

DT is great but I do prefer to rely on the SoC register here as the whole was
also to check that the is correct

wihich is way slower

Best Regards,
J.
> + 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;
> + }
> +
> if (at91_cpuidle_device.dev.platform_data)
> platform_device_register(&at91_cpuidle_device);
>
> --
> 2.1.0
>
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