* [PATCH v3 1/3] ARM: at91: pm: add support for ULP0 fast wakeup
2020-08-05 8:36 [PATCH v3 0/3] AT91 PM improvements Claudiu Beznea
@ 2020-08-05 8:36 ` Claudiu Beznea
2020-08-05 8:36 ` [PATCH v3 2/3] ARM: at91: pm: add per soc validation of pm modes Claudiu Beznea
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Claudiu Beznea @ 2020-08-05 8:36 UTC (permalink / raw)
To: nicolas.ferre, alexandre.belloni, ludovic.desroches
Cc: linux-arm-kernel, linux-kernel, Claudiu Beznea
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 <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(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 074bde64064e..04fdcbd57100 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
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v3 2/3] ARM: at91: pm: add per soc validation of pm modes
2020-08-05 8:36 [PATCH v3 0/3] AT91 PM improvements Claudiu Beznea
2020-08-05 8:36 ` [PATCH v3 1/3] ARM: at91: pm: add support for ULP0 fast wakeup Claudiu Beznea
@ 2020-08-05 8:36 ` Claudiu Beznea
2020-08-05 8:36 ` [PATCH v3 3/3] ARM: at91: pm: of_node_put() after its usage Claudiu Beznea
2020-08-17 9:20 ` [PATCH v3 0/3] AT91 PM improvements Alexandre Belloni
3 siblings, 0 replies; 5+ messages in thread
From: Claudiu Beznea @ 2020-08-05 8:36 UTC (permalink / raw)
To: nicolas.ferre, alexandre.belloni, ludovic.desroches
Cc: linux-arm-kernel, linux-kernel, Claudiu Beznea
Not all SoCs supports all the PM mode. User may end up settings,
e.g. backup mode, on a non SAMA5D2 device, but the mode to not be valid.
If backup mode is used on a devices not supporting it there will be no
way of resuming other than rebooting.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
arch/arm/mach-at91/pm.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 79 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 04fdcbd57100..4aaab918f982 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -785,6 +785,51 @@ static const struct of_device_id atmel_pmc_ids[] __initconst = {
{ /* sentinel */ },
};
+static void __init at91_pm_modes_validate(const int *modes, int len)
+{
+ u8 i, standby = 0, suspend = 0;
+ int mode;
+
+ for (i = 0; i < len; i++) {
+ if (standby && suspend)
+ break;
+
+ if (modes[i] == soc_pm.data.standby_mode && !standby) {
+ standby = 1;
+ continue;
+ }
+
+ if (modes[i] == soc_pm.data.suspend_mode && !suspend) {
+ suspend = 1;
+ continue;
+ }
+ }
+
+ if (!standby) {
+ if (soc_pm.data.suspend_mode == AT91_PM_STANDBY)
+ mode = AT91_PM_ULP0;
+ else
+ mode = AT91_PM_STANDBY;
+
+ pr_warn("AT91: PM: %s mode not supported! Using %s.\n",
+ pm_modes[soc_pm.data.standby_mode].pattern,
+ pm_modes[mode].pattern);
+ soc_pm.data.standby_mode = mode;
+ }
+
+ if (!suspend) {
+ if (soc_pm.data.standby_mode == AT91_PM_ULP0)
+ mode = AT91_PM_STANDBY;
+ else
+ mode = AT91_PM_ULP0;
+
+ pr_warn("AT91: PM: %s mode not supported! Using %s.\n",
+ pm_modes[soc_pm.data.suspend_mode].pattern,
+ pm_modes[mode].pattern);
+ soc_pm.data.suspend_mode = mode;
+ }
+}
+
static void __init at91_pm_init(void (*pm_idle)(void))
{
struct device_node *pmc_np;
@@ -826,6 +871,14 @@ void __init at91rm9200_pm_init(void)
if (!IS_ENABLED(CONFIG_SOC_AT91RM9200))
return;
+ /*
+ * Force STANDBY and ULP0 mode to avoid calling
+ * at91_pm_modes_validate() which may increase booting time.
+ * Platform supports anyway only STANDBY and ULP0 modes.
+ */
+ soc_pm.data.standby_mode = AT91_PM_STANDBY;
+ soc_pm.data.suspend_mode = AT91_PM_ULP0;
+
at91_dt_ramc();
/*
@@ -838,9 +891,14 @@ void __init at91rm9200_pm_init(void)
void __init sam9x60_pm_init(void)
{
+ static const int modes[] __initconst = {
+ AT91_PM_STANDBY, AT91_PM_ULP0, AT91_PM_ULP0_FAST, AT91_PM_ULP1,
+ };
+
if (!IS_ENABLED(CONFIG_SOC_SAM9X60))
return;
+ at91_pm_modes_validate(modes, ARRAY_SIZE(modes));
at91_pm_modes_init();
at91_dt_ramc();
at91_pm_init(at91sam9x60_idle);
@@ -854,26 +912,46 @@ void __init at91sam9_pm_init(void)
if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
return;
+ /*
+ * Force STANDBY and ULP0 mode to avoid calling
+ * at91_pm_modes_validate() which may increase booting time.
+ * Platform supports anyway only STANDBY and ULP0 modes.
+ */
+ soc_pm.data.standby_mode = AT91_PM_STANDBY;
+ soc_pm.data.suspend_mode = AT91_PM_ULP0;
+
at91_dt_ramc();
at91_pm_init(at91sam9_idle);
}
void __init sama5_pm_init(void)
{
+ static const int modes[] __initconst = {
+ AT91_PM_STANDBY, AT91_PM_ULP0, AT91_PM_ULP0_FAST,
+ };
+
if (!IS_ENABLED(CONFIG_SOC_SAMA5))
return;
+ at91_pm_modes_validate(modes, ARRAY_SIZE(modes));
at91_dt_ramc();
at91_pm_init(NULL);
}
void __init sama5d2_pm_init(void)
{
+ static const int modes[] __initconst = {
+ AT91_PM_STANDBY, AT91_PM_ULP0, AT91_PM_ULP0_FAST, AT91_PM_ULP1,
+ AT91_PM_BACKUP,
+ };
+
if (!IS_ENABLED(CONFIG_SOC_SAMA5D2))
return;
+ at91_pm_modes_validate(modes, ARRAY_SIZE(modes));
at91_pm_modes_init();
- sama5_pm_init();
+ at91_dt_ramc();
+ at91_pm_init(NULL);
soc_pm.ws_ids = sama5d2_ws_ids;
soc_pm.config_shdwc_ws = at91_sama5d2_config_shdwc_ws;
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread