From e70bfc2fa8fe1a95a522f9d1ccf24d3d9b81366a Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Wed, 5 Aug 2020 11:36:48 +0300 Subject: ARM: at91: pm: add support for ULP0 fast wakeup ULP0 fast improves suspend/resume time with few milliseconds the drawback being the power consumption. The mean values measured for suspend/resume time are as follows (measured on SAMA5D2 Xplained board), ULP0 compared with fast ULP0: - ulp0 fast: suspend time: 169 ms, resume time: 216 ms - ulp0 : suspend time: 197 ms, resume time: 258 ms Current consumption while suspended (measured on SAMA5D2 Xplained board): - ulp0 fast: 730uA - ulp0 : 270uA Signed-off-by: Claudiu Beznea Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/1596616610-15460-2-git-send-email-claudiu.beznea@microchip.com --- arch/arm/mach-at91/pm.c | 9 +++++---- arch/arm/mach-at91/pm.h | 5 +++-- arch/arm/mach-at91/pm_suspend.S | 41 +++++++++++++++++++++++++++++++++++++---- 3 files changed, 45 insertions(+), 10 deletions(-) (limited to 'arch/arm/mach-at91') diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index 2aab043441e8..a6336af1f449 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -51,10 +51,11 @@ static struct at91_soc_pm soc_pm = { }; static const match_table_t pm_modes __initconst = { - { AT91_PM_STANDBY, "standby" }, - { AT91_PM_ULP0, "ulp0" }, - { AT91_PM_ULP1, "ulp1" }, - { AT91_PM_BACKUP, "backup" }, + { AT91_PM_STANDBY, "standby" }, + { AT91_PM_ULP0, "ulp0" }, + { AT91_PM_ULP0_FAST, "ulp0-fast" }, + { AT91_PM_ULP1, "ulp1" }, + { AT91_PM_BACKUP, "backup" }, { -1, NULL }, }; diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h index 218e8d1a30fb..bfb260be371e 100644 --- a/arch/arm/mach-at91/pm.h +++ b/arch/arm/mach-at91/pm.h @@ -19,8 +19,9 @@ #define AT91_PM_STANDBY 0x00 #define AT91_PM_ULP0 0x01 -#define AT91_PM_ULP1 0x02 -#define AT91_PM_BACKUP 0x03 +#define AT91_PM_ULP0_FAST 0x02 +#define AT91_PM_ULP1 0x03 +#define AT91_PM_BACKUP 0x04 #ifndef __ASSEMBLY__ struct at91_pm_data { diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S index be9764e8d3fa..0184de05c1be 100644 --- a/arch/arm/mach-at91/pm_suspend.S +++ b/arch/arm/mach-at91/pm_suspend.S @@ -164,7 +164,22 @@ ENDPROC(at91_backup_mode) .macro at91_pm_ulp0_mode ldr pmc, .pmc_base + ldr tmp2, .pm_mode + ldr tmp3, .mckr_offset + + /* Check if ULP0 fast variant has been requested. */ + cmp tmp2, #AT91_PM_ULP0_FAST + bne 0f + + /* Set highest prescaler for power saving */ + ldr tmp1, [pmc, tmp3] + bic tmp1, tmp1, #AT91_PMC_PRES + orr tmp1, tmp1, #AT91_PMC_PRES_64 + str tmp1, [pmc, tmp3] + wait_mckrdy + b 1f +0: /* Turn off the crystal oscillator */ ldr tmp1, [pmc, #AT91_CKGR_MOR] bic tmp1, tmp1, #AT91_PMC_MOSCEN @@ -192,7 +207,18 @@ ENDPROC(at91_backup_mode) /* Wait for interrupt */ 1: at91_cpu_idle - /* Restore RC oscillator state */ + /* Check if ULP0 fast variant has been requested. */ + cmp tmp2, #AT91_PM_ULP0_FAST + bne 5f + + /* Set lowest prescaler for fast resume. */ + ldr tmp1, [pmc, tmp3] + bic tmp1, tmp1, #AT91_PMC_PRES + str tmp1, [pmc, tmp3] + wait_mckrdy + b 6f + +5: /* Restore RC oscillator state */ ldr tmp1, .saved_osc_status tst tmp1, #AT91_PMC_MOSCRCS beq 4f @@ -216,6 +242,7 @@ ENDPROC(at91_backup_mode) str tmp1, [pmc, #AT91_CKGR_MOR] wait_moscrdy +6: .endm /** @@ -473,23 +500,29 @@ ENDPROC(at91_backup_mode) ENTRY(at91_ulp_mode) ldr pmc, .pmc_base ldr tmp2, .mckr_offset + ldr tmp3, .pm_mode /* Save Master clock setting */ ldr tmp1, [pmc, tmp2] str tmp1, .saved_mckr /* - * Set the Master clock source to slow clock + * Set master clock source to: + * - MAINCK if using ULP0 fast variant + * - slow clock, otherwise */ bic tmp1, tmp1, #AT91_PMC_CSS + cmp tmp3, #AT91_PM_ULP0_FAST + bne save_mck + orr tmp1, tmp1, #AT91_PMC_CSS_MAIN +save_mck: str tmp1, [pmc, tmp2] wait_mckrdy at91_plla_disable - ldr r0, .pm_mode - cmp r0, #AT91_PM_ULP1 + cmp tmp3, #AT91_PM_ULP1 beq ulp1_mode at91_pm_ulp0_mode -- cgit v1.2.3