[PATCH v5 0/5] ARM: at91: pm: add ULP1 mode support

[PATCH v5 0/5] ARM: at91: pm: add ULP1 mode support

[Wenyou Yang]

The ULP1 (Ultra Low-power mode 1) is introduced by SAMA5D2.

In order to achieve the lowest power consumption, in the ULP1 mode,
all the clocks are shut off, inclusive the embedded 12MHz RC oscillator.

The fast startup signal is used as a wake up source for ULP1 mode.
As soon as the wake up event is asserted, the embedded 12MHz RC
oscillator restarts automatically, which fast startup signal
to trigger the PMC to wake up the system from the ULP1 mode can be
configured via DT.

Changes in v5:
 - to improve the scalability, rework the DT expression part, use
   the child nodes to describe the wake-up input and its active level.
 - due to the DT property expression change, update the binding
   document.
 - due to the DT property expression change, update the fast restart
   node's property.

Changes in v4:
 - add Acked-by tag.
 - add fast_restart node to the DT file.

Changes in v3:
 - use 0 and 1, not string, to define the trigger active polarity.
 - update the property description.

Changes in v2:
 - fix label pm_exit to ulp_exit.
 - shorten the pmc-fast-startup property's name.
 - use the value property, instead of bool property for high
   or low triggered.
 - change the property name and property description.

Wenyou Yang (5):
  ARM: at91: pm: create a separate procedure for the ULP0 mode
  ARM: at91: pm: add ULP1 mode support
  ARM: at91: pm: configure PMC fast startup signals
  Documentation: atmel-pmc: add DT bindings for fast startup
  ARM: at91/dt: sama5d2_xplained: add fast_restart node

 .../devicetree/bindings/arm/atmel-pmc.txt          |   52 +++++++
 arch/arm/boot/dts/at91-sama5d2_xplained.dts        |   19 +++
 arch/arm/mach-at91/pm.c                            |   82 +++++++++-
 arch/arm/mach-at91/pm.h                            |    7 +
 arch/arm/mach-at91/pm_suspend.S                    |  158 +++++++++++++++++---
 include/linux/clk/at91_pmc.h                       |   18 +++
 6 files changed, 311 insertions(+), 25 deletions(-)

-- 
1.7.9.5

[PATCH v5 1/5] ARM: at91: pm: create a separate procedure for the ULP0 mode

[Wenyou Yang]

To make the code more legible and prepare to add the ULP1 mode
support in the future, create a separate procedure for the ULP0 mode.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 arch/arm/mach-at91/pm_suspend.S |   65 ++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 25 deletions(-)

diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index a25defd..5fcffdc 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -107,7 +107,7 @@ ENTRY(at91_pm_suspend_in_sram)
 
 	ldr	r0, .pm_mode
 	tst	r0, #AT91_PM_SLOW_CLOCK
-	beq	skip_disable_main_clock
+	beq	standby_mode
 
 	ldr	pmc, .pmc_base
 
@@ -131,32 +131,13 @@ ENTRY(at91_pm_suspend_in_sram)
 	orr	tmp1, tmp1, #(1 << 29)		/* bit 29 always set */
 	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
 
-	/* Turn off the main oscillator */
-	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
-	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
-	orr	tmp1, tmp1, #AT91_PMC_KEY
-	str	tmp1, [pmc, #AT91_CKGR_MOR]
-
-skip_disable_main_clock:
-	ldr	pmc, .pmc_base
-
-	/* Wait for interrupt */
-	at91_cpu_idle
-
-	ldr	r0, .pm_mode
-	tst	r0, #AT91_PM_SLOW_CLOCK
-	beq	skip_enable_main_clock
+ulp0_mode:
+	bl	at91_pm_ulp0_mode
+	b	ulp_exit
 
+ulp_exit:
 	ldr	pmc, .pmc_base
 
-	/* Turn on the main oscillator */
-	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
-	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
-	orr	tmp1, tmp1, #AT91_PMC_KEY
-	str	tmp1, [pmc, #AT91_CKGR_MOR]
-
-	wait_moscrdy
-
 	/* Restore PLLA setting */
 	ldr	tmp1, .saved_pllar
 	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
@@ -177,7 +158,15 @@ skip_disable_main_clock:
 
 	wait_mckrdy
 
-skip_enable_main_clock:
+	b	pm_exit
+
+standby_mode:
+	ldr	pmc, .pmc_base
+
+	/* Wait for interrupt */
+	at91_cpu_idle
+
+pm_exit:
 	/* Exit the self-refresh mode */
 	mov	r0, #SRAMC_SELF_FRESH_EXIT
 	bl	at91_sramc_self_refresh
@@ -311,6 +300,32 @@ exit_sramc_sf:
 	mov	pc, lr
 ENDPROC(at91_sramc_self_refresh)
 
+/*
+ * void at91_pm_ulp0_mode(void)
+ */
+ENTRY(at91_pm_ulp0_mode)
+	ldr	pmc, .pmc_base
+
+	/* Turn off the crystal oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	/* Wait for interrupt */
+	at91_cpu_idle
+
+	/* Turn on the crystal oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	wait_moscrdy
+
+	mov	pc, lr
+ENDPROC(at91_pm_ulp0_mode)
+
 .pmc_base:
 	.word 0
 .sramc_base:
-- 
1.7.9.5

[PATCH v5 2/5] ARM: at91: pm: add ULP1 mode support

[Wenyou Yang]

The ULP1 (Ultra Low-power mode 1) is introduced by SAMA5D2.

In the ULP1 mode, all the clocks are shut off, inclusive the embedded
12MHz RC oscillator, so as to achieve the lowest power consumption
with the system in retention mode and able to resume on the wake up
events. As soon as the wake up event is asserted, the embedded 12MHz
RC oscillator restarts automatically.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2:
 - fix label pm_exit to ulp_exit.

 arch/arm/mach-at91/pm.c         |   16 ++++++-
 arch/arm/mach-at91/pm.h         |    7 +++
 arch/arm/mach-at91/pm_suspend.S |   97 +++++++++++++++++++++++++++++++++++++++
 include/linux/clk/at91_pmc.h    |    4 ++
 4 files changed, 122 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index f062701..5c2db34 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -36,6 +36,11 @@
 #include "generic.h"
 #include "pm.h"
 
+#define ULP0_MODE	0x00
+#define ULP1_MODE	0x11
+
+#define SAMA5D2_PMC_VERSION	0x20540
+
 static void __iomem *pmc;
 
 /*
@@ -52,6 +57,7 @@ extern void at91_pinctrl_gpio_resume(void);
 static struct {
 	unsigned long uhp_udp_mask;
 	int memctrl;
+	u32 ulp_mode;
 } at91_pm_data;
 
 void __iomem *at91_ramc_base[2];
@@ -141,8 +147,11 @@ static void at91_pm_suspend(suspend_state_t state)
 {
 	unsigned int pm_data = at91_pm_data.memctrl;
 
-	pm_data |= (state == PM_SUSPEND_MEM) ?
-				AT91_PM_MODE(AT91_PM_SLOW_CLOCK) : 0;
+	if (state == PM_SUSPEND_MEM) {
+		pm_data |= AT91_PM_MODE(AT91_PM_SLOW_CLOCK);
+		if (at91_pm_data.ulp_mode == ULP1_MODE)
+			pm_data |= AT91_PM_ULP(AT91_PM_ULP1_MODE);
+	}
 
 	flush_cache_all();
 	outer_disable();
@@ -497,4 +506,7 @@ void __init sama5_pm_init(void)
 	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
 	at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
 	at91_pm_init(NULL);
+
+	if (readl(pmc + AT91_PMC_VERSION) >= SAMA5D2_PMC_VERSION)
+		at91_pm_data.ulp_mode = ULP1_MODE;
 }
diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h
index 3fcf881..2e76745 100644
--- a/arch/arm/mach-at91/pm.h
+++ b/arch/arm/mach-at91/pm.h
@@ -39,4 +39,11 @@ extern void __iomem *at91_ramc_base[];
 
 #define	AT91_PM_SLOW_CLOCK	0x01
 
+#define AT91_PM_ULP_OFFSET	5
+#define AT91_PM_ULP_MASK	0x03
+#define AT91_PM_ULP(x)		(((x) & AT91_PM_ULP_MASK) << AT91_PM_ULP_OFFSET)
+
+#define AT91_PM_ULP0_MODE	0x00
+#define AT91_PM_ULP1_MODE	0x01
+
 #endif
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index 5fcffdc..f2a5c4b 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -41,6 +41,15 @@ tmp2	.req	r5
 	.endm
 
 /*
+ * Wait for main oscillator selection is done
+ */
+	.macro wait_moscsels
+1:	ldr	tmp1, [pmc, #AT91_PMC_SR]
+	tst	tmp1, #AT91_PMC_MOSCSELS
+	beq	1b
+	.endm
+
+/*
  * Wait until PLLA has locked.
  */
 	.macro wait_pllalock
@@ -101,6 +110,10 @@ ENTRY(at91_pm_suspend_in_sram)
 	and	r0, r0, #AT91_PM_MODE_MASK
 	str	r0, .pm_mode
 
+	lsr	r0, r3, #AT91_PM_ULP_OFFSET
+	and	r0, r0, #AT91_PM_ULP_MASK
+	str	r0, .ulp_mode
+
 	/* Active the self-refresh mode */
 	mov	r0, #SRAMC_SELF_FRESH_ACTIVE
 	bl	at91_sramc_self_refresh
@@ -131,6 +144,13 @@ ENTRY(at91_pm_suspend_in_sram)
 	orr	tmp1, tmp1, #(1 << 29)		/* bit 29 always set */
 	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
 
+	ldr	r0, .ulp_mode
+	tst	r0, #AT91_PM_ULP1_MODE
+	beq	ulp0_mode
+
+	bl	at91_pm_ulp1_mode
+	b	ulp_exit
+
 ulp0_mode:
 	bl	at91_pm_ulp0_mode
 	b	ulp_exit
@@ -326,6 +346,81 @@ ENTRY(at91_pm_ulp0_mode)
 	mov	pc, lr
 ENDPROC(at91_pm_ulp0_mode)
 
+/*
+ * void at91_pm_ulp1_mode(void)
+ */
+ENTRY(at91_pm_ulp1_mode)
+	ldr	pmc, .pmc_base
+
+	/* Switch the main clock source to 12-MHz RC oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	bic	tmp1, tmp1, #AT91_PMC_MOSCSEL
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	wait_moscsels
+
+	/* Disable the crystal oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	/* Switch the master clock source to main clock */
+	ldr	tmp1, [pmc, #AT91_PMC_MCKR]
+	bic	tmp1, tmp1, #AT91_PMC_CSS
+	orr	tmp1, tmp1, #AT91_PMC_CSS_MAIN
+	str	tmp1, [pmc, #AT91_PMC_MCKR]
+
+	wait_mckrdy
+
+	/* Enter the ULP1 mode by set WAITMODE bit in CKGR_MOR */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	orr	tmp1, tmp1, #AT91_PMC_WAITMODE
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	wait_mckrdy
+
+	/* Enable the crystal oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	wait_moscrdy
+
+	/* Switch the master clock source to slow clock */
+	ldr	tmp1, [pmc, #AT91_PMC_MCKR]
+	bic	tmp1, tmp1, #AT91_PMC_CSS
+	str	tmp1, [pmc, #AT91_PMC_MCKR]
+
+	wait_mckrdy
+
+	/* Switch main clock source to crystal oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	orr	tmp1, tmp1, #AT91_PMC_MOSCSEL
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	wait_moscsels
+
+	/* Switch the master clock source to main clock */
+	ldr	tmp1, [pmc, #AT91_PMC_MCKR]
+	bic	tmp1, tmp1, #AT91_PMC_CSS
+	orr	tmp1, tmp1, #AT91_PMC_CSS_MAIN
+	str	tmp1, [pmc, #AT91_PMC_MCKR]
+
+	wait_mckrdy
+
+	mov	pc, lr
+ENDPROC(at91_pm_ulp1_mode)
+
 .pmc_base:
 	.word 0
 .sramc_base:
@@ -336,6 +431,8 @@ ENDPROC(at91_pm_ulp0_mode)
 	.word 0
 .pm_mode:
 	.word 0
+.ulp_mode:
+	.word 0
 .saved_mckr:
 	.word 0
 .saved_pllar:
diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h
index 17f413b..4afd891 100644
--- a/include/linux/clk/at91_pmc.h
+++ b/include/linux/clk/at91_pmc.h
@@ -47,8 +47,10 @@
 #define	AT91_CKGR_MOR		0x20			/* Main Oscillator Register [not on SAM9RL] */
 #define		AT91_PMC_MOSCEN		(1    <<  0)		/* Main Oscillator Enable */
 #define		AT91_PMC_OSCBYPASS	(1    <<  1)		/* Oscillator Bypass */
+#define		AT91_PMC_WAITMODE	(1    <<  2)		/* Wait Mode Command */
 #define		AT91_PMC_MOSCRCEN	(1    <<  3)		/* Main On-Chip RC Oscillator Enable [some SAM9] */
 #define		AT91_PMC_OSCOUNT	(0xff <<  8)		/* Main Oscillator Start-up Time */
+#define		AT91_PMC_KEY_MASK	(0xff << 16)
 #define		AT91_PMC_KEY		(0x37 << 16)		/* MOR Writing Key */
 #define		AT91_PMC_MOSCSEL	(1    << 24)		/* Main Oscillator Selection [some SAM9] */
 #define		AT91_PMC_CFDEN		(1    << 25)		/* Clock Failure Detector Enable [some SAM9] */
@@ -166,6 +168,8 @@
 #define		AT91_PMC_WPVS		(0x1  <<  0)		/* Write Protect Violation Status */
 #define		AT91_PMC_WPVSRC		(0xffff  <<  8)		/* Write Protect Violation Source */
 
+#define AT91_PMC_VERSION	0xfc
+
 #define AT91_PMC_PCER1		0x100			/* Peripheral Clock Enable Register 1 [SAMA5 only]*/
 #define AT91_PMC_PCDR1		0x104			/* Peripheral Clock Enable Register 1 */
 #define AT91_PMC_PCSR1		0x108			/* Peripheral Clock Enable Register 1 */
-- 
1.7.9.5

[PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals

[Wenyou Yang]

The fast startup signal is used as wake up sources for ULP1 mode.
As soon as a fast startup signal is asserted, the embedded 12 MHz
RC oscillator restarts automatically.

This patch is to configure the fast startup signals, which signal
is enabled to trigger the PMC to wake up the system from ULP1 mode
should be configured via the DT.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
---

Changes in v5:
 - to improve the scalability, rework the DT expression part, use
   the child nodes to describe the wake-up input and its active level.

Changes in v4: None
Changes in v3:
 - use 0 and 1, not string, to define the trigger active polarity.

Changes in v2:
 - shorten the pmc-fast-startup property's name.
 - use the value property, instead of bool property for high
   or low triggered.

 arch/arm/mach-at91/pm.c      |   66 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/clk/at91_pmc.h |   14 +++++++++
 2 files changed, 80 insertions(+)

diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 5c2db34..29895f1 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -24,6 +24,8 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/clk/at91_pmc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <asm/irq.h>
 #include <linux/atomic.h>
@@ -461,6 +463,68 @@ static void __init at91_pm_init(void (*pm_idle)(void))
 		pr_info("AT91: PM not supported, due to no SRAM allocated\n");
 }
 
+static int __init at91_pmc_fast_startup_init(void)
+{
+	struct device_node *np, *cnp;
+	struct regmap *regmap;
+	u32 input, input_mask;
+	u32 mode = 0, polarity = 0;
+
+	np = of_find_compatible_node(NULL, NULL,
+				     "atmel,sama5d2-pmc-fast-startup");
+	if (!np)
+		return -ENODEV;
+
+	regmap = syscon_node_to_regmap(of_get_parent(np));
+	if (IS_ERR(regmap)) {
+		pr_info("AT91: failed to find PMC fast startup node\n");
+		return PTR_ERR(regmap);
+	}
+
+	for_each_child_of_node(np, cnp) {
+		if (of_property_read_u32(cnp, "reg", &input)) {
+			pr_warn("AT91: reg property is missing for %s\n",
+				cnp->full_name);
+			continue;
+		}
+
+		input_mask = 1 << input;
+		if (!(input_mask & AT91_PMC_FS_INPUT_MASK)) {
+			pr_warn("AT91: wake-up input %d out of range\n", input);
+			continue;
+		}
+		mode |= input_mask;
+
+		if (of_property_read_bool(cnp, "atmel,wakeup-active-high"))
+			polarity |= input_mask;
+	}
+
+	if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
+		mode |= AT91_PMC_RTCAL;
+
+	if (of_property_read_bool(np, "atmel,wakeup-usb-resume"))
+		mode |= AT91_PMC_USBAL;
+
+	if (of_property_read_bool(np, "atmel,wakeup-sdmmc-cd"))
+		mode |= AT91_PMC_SDMMC_CD;
+
+	if (of_property_read_bool(np, "atmel,wakeup-rxlp-match"))
+		mode |= AT91_PMC_RXLP_MCE;
+
+	if (of_property_read_bool(np, "atmel,wakeup-acc-comparison"))
+		mode |= AT91_PMC_ACC_CE;
+
+	pr_debug("AT91: mode = 0x%x, ploarity = 0%x\n", mode, polarity);
+
+	regmap_write(regmap, AT91_PMC_FSMR, mode);
+
+	regmap_write(regmap, AT91_PMC_FSPR, polarity);
+
+	of_node_put(np);
+
+	return 0;
+}
+
 void __init at91rm9200_pm_init(void)
 {
 	at91_dt_ramc();
@@ -509,4 +573,6 @@ void __init sama5_pm_init(void)
 
 	if (readl(pmc + AT91_PMC_VERSION) >= SAMA5D2_PMC_VERSION)
 		at91_pm_data.ulp_mode = ULP1_MODE;
+
+	at91_pmc_fast_startup_init();
 }
diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h
index 4afd891..4b942c5 100644
--- a/include/linux/clk/at91_pmc.h
+++ b/include/linux/clk/at91_pmc.h
@@ -168,6 +168,20 @@
 #define		AT91_PMC_WPVS		(0x1  <<  0)		/* Write Protect Violation Status */
 #define		AT91_PMC_WPVSRC		(0xffff  <<  8)		/* Write Protect Violation Source */
 
+#define AT91_PMC_FSMR		0x70		/* Fast Startup Mode Register */
+#define AT91_PMC_FSTT(n)	(0x1 << n)
+#define AT91_PMC_RTCAL		BIT(17)		/* RTC Alarm Enable */
+#define AT91_PMC_USBAL		BIT(18)		/* USB Resume Enable */
+#define AT91_PMC_SDMMC_CD	BIT(19)		/* SDMMC Card Detect Enable */
+#define AT91_PMC_LPM		BIT(20)		/* Low-power Mode */
+#define AT91_PMC_RXLP_MCE	BIT(24)		/* Backup UART Receive Enable */
+#define AT91_PMC_ACC_CE		BIT(25)		/* ACC Enable */
+
+#define AT91_PMC_FSPR		0x74		/* Fast Startup Polarity Reg */
+#define AT91_PMC_FSTP(n)	(0x1 << n)
+
+#define AT91_PMC_FS_INPUT_MASK  0x7ff
+
 #define AT91_PMC_VERSION	0xfc
 
 #define AT91_PMC_PCER1		0x100			/* Peripheral Clock Enable Register 1 [SAMA5 only]*/
-- 
1.7.9.5

[PATCH v5 4/5] Documentation: atmel-pmc: add DT bindings for fast startup

[Wenyou Yang]

Add DT bindings to configurate the PMC_FSMR and PMC_FSPR registers
to trigger a fast restart signal to PMC.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Rob Herring <robh+dt@kernel.org>
---

Changes in v5:
 - due to the DT property expression change, update the binding
   document.

Changes in v4:
 - add Acked-by tag.

Changes in v3:
 - update the property description.

Changes in v2:
 - change the property name and property description.

 .../devicetree/bindings/arm/atmel-pmc.txt          |   52 ++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/atmel-pmc.txt b/Documentation/devicetree/bindings/arm/atmel-pmc.txt
index 795cc78..76fdc66 100644
--- a/Documentation/devicetree/bindings/arm/atmel-pmc.txt
+++ b/Documentation/devicetree/bindings/arm/atmel-pmc.txt
@@ -12,3 +12,55 @@ Examples:
 		compatible = "atmel,at91rm9200-pmc";
 		reg = <0xfffffc00 0x100>;
 	};
+
+PMC Fast Startup Signals
+
+The PMC Fast Start Signals are used as the wake up source to trigger the PMC
+to wake up the system from the ULP1 mode.
+
+required properties:
+- compatible: should be "atmel,sama5d2-pmc-fast-startup".
+
+optional properties:
+- atmel,wakeup-rtc-timer: boolean to enable RTC alarm wake-up.
+- atmel,wakeup-usb-resume: boolean to enable USB resume wake-up.
+- atmel,wakeup-sdmmc-cd: boolean to enable SDMMC card detect wake-up.
+- atmel,wakeup-rxlp-match: boolean to enable RXLP matching condition wake-up.
+- atmel,wakeup-acc-comparison: boolean to enable ACC comparison wake-up.
+
+The node contains child nodes for each wake-up input pin that the platform uses.
+
+Input nodes
+
+Required properties:
+- reg: should contain the wake-up input index [0 - 10], to enable
+  the corresponding wake-up input.
+
+Optional properties:
+- atmel,wakeup-active-high: boolean to declare the corresponding wake-up
+  input described by the child be active high.
+  The default is to be active low.
+
+Example:
+
+	pmc: pmc@f0014000 {
+		compatible = "atmel,sama5d2-pmc";
+		reg = <0xf0014000 0x160>;
+
+		pmc_fast_restart {
+			compatible = "atmel,sama5d2-pmc-fast-startup";
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			atmel,wakeup-rtc-timer;
+
+			wkpin: input@0 {
+				reg = <0>;
+			};
+
+			gmac_wol: input@10 {
+				reg = <10>;
+				atmel,wakeup-active-high;
+			};
+		};
+	};
-- 
1.7.9.5

[PATCH v5 5/5] ARM: at91/dt: sama5d2_xplained: add fast_restart node

[Wenyou Yang]

Add fast_restart node as a pmc's child node to support fast startup
signal configuration.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
---

Changes in v5:
 - due to the DT property expression change, update the fast restart
   node's property.

Changes in v4:
 - add fast_restart node to the DT file.

Changes in v3: None
Changes in v2: None

 arch/arm/boot/dts/at91-sama5d2_xplained.dts |   19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/boot/dts/at91-sama5d2_xplained.dts b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
index 21c780f..31df6e8 100644
--- a/arch/arm/boot/dts/at91-sama5d2_xplained.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_xplained.dts
@@ -110,6 +110,25 @@
 		};
 
 		apb {
+			pmc: pmc@f0014000 {
+				pmc_fast_restart {
+					compatible = "atmel,sama5d2-pmc-fast-startup";
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					atmel,wakeup-rtc-timer;
+
+					wkpin: input@0 {
+						reg = <0>;
+					};
+
+					gmac_wol: input@10 {
+						reg = <10>;
+						atmel,wakeup-active-high;
+					};
+				};
+			};
+
 			spi0: spi@f8000000 {
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_spi0_default>;
-- 
1.7.9.5

Re: [PATCH v5 1/5] ARM: at91: pm: create a separate procedure for the ULP0 mode

[Alexandre Belloni]

On 16/03/2016 at 14:58:05 +0800, Wenyou Yang wrote :
> To make the code more legible and prepare to add the ULP1 mode
> support in the future, create a separate procedure for the ULP0 mode.
> 
> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

> ---
> 
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
> 
>  arch/arm/mach-at91/pm_suspend.S |   65 ++++++++++++++++++++++++---------------
>  1 file changed, 40 insertions(+), 25 deletions(-)
> 
> diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
> index a25defd..5fcffdc 100644
> --- a/arch/arm/mach-at91/pm_suspend.S
> +++ b/arch/arm/mach-at91/pm_suspend.S
> @@ -107,7 +107,7 @@ ENTRY(at91_pm_suspend_in_sram)
>  
>  	ldr	r0, .pm_mode
>  	tst	r0, #AT91_PM_SLOW_CLOCK
> -	beq	skip_disable_main_clock
> +	beq	standby_mode
>  
>  	ldr	pmc, .pmc_base
>  
> @@ -131,32 +131,13 @@ ENTRY(at91_pm_suspend_in_sram)
>  	orr	tmp1, tmp1, #(1 << 29)		/* bit 29 always set */
>  	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
>  
> -	/* Turn off the main oscillator */
> -	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> -	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
> -	orr	tmp1, tmp1, #AT91_PMC_KEY
> -	str	tmp1, [pmc, #AT91_CKGR_MOR]
> -
> -skip_disable_main_clock:
> -	ldr	pmc, .pmc_base
> -
> -	/* Wait for interrupt */
> -	at91_cpu_idle
> -
> -	ldr	r0, .pm_mode
> -	tst	r0, #AT91_PM_SLOW_CLOCK
> -	beq	skip_enable_main_clock
> +ulp0_mode:
> +	bl	at91_pm_ulp0_mode
> +	b	ulp_exit
>  
> +ulp_exit:
>  	ldr	pmc, .pmc_base
>  
> -	/* Turn on the main oscillator */
> -	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> -	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
> -	orr	tmp1, tmp1, #AT91_PMC_KEY
> -	str	tmp1, [pmc, #AT91_CKGR_MOR]
> -
> -	wait_moscrdy
> -
>  	/* Restore PLLA setting */
>  	ldr	tmp1, .saved_pllar
>  	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
> @@ -177,7 +158,15 @@ skip_disable_main_clock:
>  
>  	wait_mckrdy
>  
> -skip_enable_main_clock:
> +	b	pm_exit
> +
> +standby_mode:
> +	ldr	pmc, .pmc_base
> +
> +	/* Wait for interrupt */
> +	at91_cpu_idle
> +
> +pm_exit:
>  	/* Exit the self-refresh mode */
>  	mov	r0, #SRAMC_SELF_FRESH_EXIT
>  	bl	at91_sramc_self_refresh
> @@ -311,6 +300,32 @@ exit_sramc_sf:
>  	mov	pc, lr
>  ENDPROC(at91_sramc_self_refresh)
>  
> +/*
> + * void at91_pm_ulp0_mode(void)
> + */
> +ENTRY(at91_pm_ulp0_mode)
> +	ldr	pmc, .pmc_base
> +
> +	/* Turn off the crystal oscillator */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +
> +	/* Wait for interrupt */
> +	at91_cpu_idle
> +
> +	/* Turn on the crystal oscillator */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +
> +	wait_moscrdy
> +
> +	mov	pc, lr
> +ENDPROC(at91_pm_ulp0_mode)
> +
>  .pmc_base:
>  	.word 0
>  .sramc_base:
> -- 
> 1.7.9.5
> 

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH v5 2/5] ARM: at91: pm: add ULP1 mode support

[Alexandre Belloni]

On 16/03/2016 at 14:58:06 +0800, Wenyou Yang wrote :
> @@ -497,4 +506,7 @@ void __init sama5_pm_init(void)
>  	at91_pm_data.uhp_udp_mask = AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP;
>  	at91_pm_data.memctrl = AT91_MEMCTRL_DDRSDR;
>  	at91_pm_init(NULL);
> +
> +	if (readl(pmc + AT91_PMC_VERSION) >= SAMA5D2_PMC_VERSION)

I would not use that. Instead, I would create a new function,
sama5d2_pm_init() and call it from sama5.c with a new
sama5d2_dt_device_init and a new DT_MACHINE.

> +		at91_pm_data.ulp_mode = ULP1_MODE;
>  }
> diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h
> index 3fcf881..2e76745 100644
> --- a/arch/arm/mach-at91/pm.h
> +++ b/arch/arm/mach-at91/pm.h
> @@ -39,4 +39,11 @@ extern void __iomem *at91_ramc_base[];
>  
>  #define	AT91_PM_SLOW_CLOCK	0x01
>  
> +#define AT91_PM_ULP_OFFSET	5
> +#define AT91_PM_ULP_MASK	0x03
> +#define AT91_PM_ULP(x)		(((x) & AT91_PM_ULP_MASK) << AT91_PM_ULP_OFFSET)
> +
> +#define AT91_PM_ULP0_MODE	0x00
> +#define AT91_PM_ULP1_MODE	0x01
> +
>  #endif
> diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
> index 5fcffdc..f2a5c4b 100644
> --- a/arch/arm/mach-at91/pm_suspend.S
> +++ b/arch/arm/mach-at91/pm_suspend.S
> @@ -41,6 +41,15 @@ tmp2	.req	r5
>  	.endm
>  
>  /*
> + * Wait for main oscillator selection is done
> + */
> +	.macro wait_moscsels
> +1:	ldr	tmp1, [pmc, #AT91_PMC_SR]
> +	tst	tmp1, #AT91_PMC_MOSCSELS
> +	beq	1b
> +	.endm
> +
> +/*
>   * Wait until PLLA has locked.
>   */
>  	.macro wait_pllalock
> @@ -101,6 +110,10 @@ ENTRY(at91_pm_suspend_in_sram)
>  	and	r0, r0, #AT91_PM_MODE_MASK
>  	str	r0, .pm_mode
>  
> +	lsr	r0, r3, #AT91_PM_ULP_OFFSET
> +	and	r0, r0, #AT91_PM_ULP_MASK
> +	str	r0, .ulp_mode
> +
>  	/* Active the self-refresh mode */
>  	mov	r0, #SRAMC_SELF_FRESH_ACTIVE
>  	bl	at91_sramc_self_refresh
> @@ -131,6 +144,13 @@ ENTRY(at91_pm_suspend_in_sram)
>  	orr	tmp1, tmp1, #(1 << 29)		/* bit 29 always set */
>  	str	tmp1, [pmc, #AT91_CKGR_PLLAR]
>  
> +	ldr	r0, .ulp_mode
> +	tst	r0, #AT91_PM_ULP1_MODE
> +	beq	ulp0_mode
> +
> +	bl	at91_pm_ulp1_mode
> +	b	ulp_exit
> +
>  ulp0_mode:
>  	bl	at91_pm_ulp0_mode
>  	b	ulp_exit
> @@ -326,6 +346,81 @@ ENTRY(at91_pm_ulp0_mode)
>  	mov	pc, lr
>  ENDPROC(at91_pm_ulp0_mode)
>  
> +/*
> + * void at91_pm_ulp1_mode(void)
> + */
> +ENTRY(at91_pm_ulp1_mode)
> +	ldr	pmc, .pmc_base
> +
> +	/* Switch the main clock source to 12-MHz RC oscillator */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	bic	tmp1, tmp1, #AT91_PMC_MOSCSEL
> +	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +
> +	wait_moscsels
> +
> +	/* Disable the crystal oscillator */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	bic	tmp1, tmp1, #AT91_PMC_MOSCEN
> +	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +
> +	/* Switch the master clock source to main clock */
> +	ldr	tmp1, [pmc, #AT91_PMC_MCKR]
> +	bic	tmp1, tmp1, #AT91_PMC_CSS
> +	orr	tmp1, tmp1, #AT91_PMC_CSS_MAIN
> +	str	tmp1, [pmc, #AT91_PMC_MCKR]
> +
> +	wait_mckrdy
> +
> +	/* Enter the ULP1 mode by set WAITMODE bit in CKGR_MOR */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	orr	tmp1, tmp1, #AT91_PMC_WAITMODE
> +	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +
> +	wait_mckrdy
> +
> +	/* Enable the crystal oscillator */
> +	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
> +	orr	tmp1, tmp1, #AT91_PMC_MOSCEN
> +	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
> +	orr	tmp1, tmp1, #AT91_PMC_KEY
> +	str	tmp1, [pmc, #AT91_CKGR_MOR]
> +

This will badly fail on the platforms that don't populate a crystal for
the main clock or use the bypass. I think wee need to have at least a
comment or save the previous state and restore it.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals

[Alexandre Belloni]

On 16/03/2016 at 14:58:07 +0800, Wenyou Yang wrote :
> The fast startup signal is used as wake up sources for ULP1 mode.
> As soon as a fast startup signal is asserted, the embedded 12 MHz
> RC oscillator restarts automatically.
> 
> This patch is to configure the fast startup signals, which signal
> is enabled to trigger the PMC to wake up the system from ULP1 mode
> should be configured via the DT.
> 
> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>

I would actually avoid doing that from the PMC driver and do that
configuration from the aic5 driver. It has all the information you need,
it knows what kind of level or edge is needed to wake up and what are
the wakeup interrupts to enable. This will allow you to stop introducing
a new binding. Also, this will avoid discrepancies between what is
configured in the DT and what the user really wants (for exemple
differences between the edge direction configured for the PIOBu in
userspace versus what is in the device tree or wakeonlan
activation/deactivation).

You can get the PMC syscon from irq-atmel-aic5.c and then use a table to
map the hwirq to the offset in PMC_FSMR. Use it in aic5_set_type to set
the polarity and then in aic5_suspend to enable the wakeup.

Maybe we could even go further and avoid ulp1 if no ulp1 compatbile
wakeup sources are defined but there are ulp0 wakeup sources.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

RE: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals

[Yang, Wenyou]

Hi Alexandre,

> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@free-electrons.com]
> Sent: 2016年3月18日 1:15
> To: Yang, Wenyou <Wenyou.Yang@atmel.com>
> Cc: Ferre, Nicolas <Nicolas.FERRE@atmel.com>; Jean-Christophe Plagniol-
> Villard <plagnioj@jcrosoft.com>; Russell King <linux@arm.linux.org.uk>; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-clk@vger.kernel.org; Rob Herring
> <robh+dt@kernel.org>; Pawel Moll <pawel.moll@arm.com>; Mark Brown
> <broonie@kernel.org>; Ian Campbell <ijc+devicetree@hellion.org.uk>; Kumar
> Gala <galak@codeaurora.org>
> Subject: Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals
> 
> On 16/03/2016 at 14:58:07 +0800, Wenyou Yang wrote :
> > The fast startup signal is used as wake up sources for ULP1 mode.
> > As soon as a fast startup signal is asserted, the embedded 12 MHz RC
> > oscillator restarts automatically.
> >
> > This patch is to configure the fast startup signals, which signal is
> > enabled to trigger the PMC to wake up the system from ULP1 mode should
> > be configured via the DT.
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> 
> I would actually avoid doing that from the PMC driver and do that configuration
> from the aic5 driver. It has all the information you need, it knows what kind of level
> or edge is needed to wake up and what are the wakeup interrupts to enable. This
> will allow you to stop introducing a new binding. Also, this will avoid discrepancies
> between what is configured in the DT and what the user really wants (for exemple
> differences between the edge direction configured for the PIOBu in userspace
> versus what is in the device tree or wakeonlan activation/deactivation).

Thank you for your feedback.

But some wake-ups such as WKUP pin, ACC_CE, RXLP_MCE, don't have the corresponding
interrupt number. Moreover, I think, the ULP1 is very different form the ULP0, it is not woken
up by the interrupt. It is fallen sleep and woken up by the some mechanism in the PMC. 

Maybe I was wrong. I still think the aic5 driver should be devoted on the AIC5's behaviors. 

> 
> You can get the PMC syscon from irq-atmel-aic5.c and then use a table to map
> the hwirq to the offset in PMC_FSMR. Use it in aic5_set_type to set the polarity
> and then in aic5_suspend to enable the wakeup.
> 
> Maybe we could even go further and avoid ulp1 if no ulp1 compatbile wakeup
> sources are defined but there are ulp0 wakeup sources.
> 
> 
> --
> Alexandre Belloni, Free Electrons
> Embedded Linux, Kernel and Android engineering http://free-electrons.com


Best Regards,
Wenyou Yang

Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals

[Alexandre Belloni]

On 21/03/2016 at 02:24:32 +0000, Yang, Wenyou wrote :
> Hi Alexandre,
> 
> > -----Original Message-----
> > From: Alexandre Belloni [mailto:alexandre.belloni@free-electrons.com]
> > Sent: 2016年3月18日 1:15
> > To: Yang, Wenyou <Wenyou.Yang@atmel.com>
> > Cc: Ferre, Nicolas <Nicolas.FERRE@atmel.com>; Jean-Christophe Plagniol-
> > Villard <plagnioj@jcrosoft.com>; Russell King <linux@arm.linux.org.uk>; linux-
> > kernel@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> > kernel@lists.infradead.org; linux-clk@vger.kernel.org; Rob Herring
> > <robh+dt@kernel.org>; Pawel Moll <pawel.moll@arm.com>; Mark Brown
> > <broonie@kernel.org>; Ian Campbell <ijc+devicetree@hellion.org.uk>; Kumar
> > Gala <galak@codeaurora.org>
> > Subject: Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals
> > 
> > On 16/03/2016 at 14:58:07 +0800, Wenyou Yang wrote :
> > > The fast startup signal is used as wake up sources for ULP1 mode.
> > > As soon as a fast startup signal is asserted, the embedded 12 MHz RC
> > > oscillator restarts automatically.
> > >
> > > This patch is to configure the fast startup signals, which signal is
> > > enabled to trigger the PMC to wake up the system from ULP1 mode should
> > > be configured via the DT.
> > >
> > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> > 
> > I would actually avoid doing that from the PMC driver and do that configuration
> > from the aic5 driver. It has all the information you need, it knows what kind of level
> > or edge is needed to wake up and what are the wakeup interrupts to enable. This
> > will allow you to stop introducing a new binding. Also, this will avoid discrepancies
> > between what is configured in the DT and what the user really wants (for exemple
> > differences between the edge direction configured for the PIOBu in userspace
> > versus what is in the device tree or wakeonlan activation/deactivation).
> 
> Thank you for your feedback.
> 
> But some wake-ups such as WKUP pin, ACC_CE, RXLP_MCE, don't have the corresponding

The WKUP pin can be configured from the shdwc driver, ACC_CE from the
ACC driver, RXLP_MCE, from the RXLP driver because you will need
drivers for those at some point anyway.

> interrupt number. Moreover, I think, the ULP1 is very different form the ULP0, it is not woken
> up by the interrupt. It is fallen sleep and woken up by the some mechanism in the PMC. 
> 

Well, we don't really care about the mechanism. We only care about how
the user is able to configure the wakeup sources.

With your patch set, what happens when no ULP1 sources are defined but
there are ULP0 sources? What happens when there are both ULP1 and ULP0
sources?

What would be good is to use ULP1 when only ULP1 sources are set up and
ULP0 in the other cases. This will greatly help the user. Also, what I'm
suggesting actually allows to change the ULP1 sources at runtime from
devices that are actually used which is quite better than setting them
up statically from DT.


-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

RE: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals

[Yang, Wenyou]

Hi Alexandre,

> -----Original Message-----
> From: Alexandre Belloni [mailto:alexandre.belloni@free-electrons.com]
> Sent: 2016年3月24日 19:25
> To: Yang, Wenyou <Wenyou.Yang@atmel.com>
> Cc: Ferre, Nicolas <Nicolas.FERRE@atmel.com>; Jean-Christophe Plagniol-
> Villard <plagnioj@jcrosoft.com>; Russell King <linux@arm.linux.org.uk>; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-clk@vger.kernel.org; Rob Herring
> <robh+dt@kernel.org>; Pawel Moll <pawel.moll@arm.com>; Mark Brown
> <broonie@kernel.org>; Ian Campbell <ijc+devicetree@hellion.org.uk>; Kumar
> Gala <galak@codeaurora.org>
> Subject: Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast startup signals
> 
> On 21/03/2016 at 02:24:32 +0000, Yang, Wenyou wrote :
> > Hi Alexandre,
> >
> > > -----Original Message-----
> > > From: Alexandre Belloni
> > > [mailto:alexandre.belloni@free-electrons.com]
> > > Sent: 2016年3月18日 1:15
> > > To: Yang, Wenyou <Wenyou.Yang@atmel.com>
> > > Cc: Ferre, Nicolas <Nicolas.FERRE@atmel.com>; Jean-Christophe
> > > Plagniol- Villard <plagnioj@jcrosoft.com>; Russell King
> > > <linux@arm.linux.org.uk>; linux- kernel@vger.kernel.org;
> > > devicetree@vger.kernel.org; linux-arm- kernel@lists.infradead.org;
> > > linux-clk@vger.kernel.org; Rob Herring <robh+dt@kernel.org>; Pawel
> > > Moll <pawel.moll@arm.com>; Mark Brown <broonie@kernel.org>; Ian
> > > Campbell <ijc+devicetree@hellion.org.uk>; Kumar Gala
> > > <galak@codeaurora.org>
> > > Subject: Re: [PATCH v5 3/5] ARM: at91: pm: configure PMC fast
> > > startup signals
> > >
> > > On 16/03/2016 at 14:58:07 +0800, Wenyou Yang wrote :
> > > > The fast startup signal is used as wake up sources for ULP1 mode.
> > > > As soon as a fast startup signal is asserted, the embedded 12 MHz
> > > > RC oscillator restarts automatically.
> > > >
> > > > This patch is to configure the fast startup signals, which signal
> > > > is enabled to trigger the PMC to wake up the system from ULP1 mode
> > > > should be configured via the DT.
> > > >
> > > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> > >
> > > I would actually avoid doing that from the PMC driver and do that
> > > configuration from the aic5 driver. It has all the information you
> > > need, it knows what kind of level or edge is needed to wake up and
> > > what are the wakeup interrupts to enable. This will allow you to
> > > stop introducing a new binding. Also, this will avoid discrepancies
> > > between what is configured in the DT and what the user really wants
> > > (for exemple differences between the edge direction configured for the PIOBu
> in userspace versus what is in the device tree or wakeonlan
> activation/deactivation).
> >
> > Thank you for your feedback.
> >
> > But some wake-ups such as WKUP pin, ACC_CE, RXLP_MCE, don't have the
> > corresponding
> 
> The WKUP pin can be configured from the shdwc driver, ACC_CE from the ACC
> driver, RXLP_MCE, from the RXLP driver because you will need drivers for those
> at some point anyway.
> 
> > interrupt number. Moreover, I think, the ULP1 is very different form
> > the ULP0, it is not woken up by the interrupt. It is fallen sleep and woken up by
> the some mechanism in the PMC.
> >
> 
> Well, we don't really care about the mechanism. We only care about how the user
> is able to configure the wakeup sources.

Understand your concerns.

> 
> With your patch set, what happens when no ULP1 sources are defined but there
> are ULP0 sources? What happens when there are both ULP1 and ULP0 sources?

I think there is only one mode, either ULP1 or ULP0, in a runtime system.
The ULP1 sources are used to wake up the ULP1, and the ULP0 sources wake up the ULP0,
they don't mutually effect each other.

If system is in the ULP1 mode, and there are no ULP1 sources defined, the system will fail to
be waken up, even though there are ULP0 sources defined. The ULP0 source can't wake up the ULP1.

> 
> What would be good is to use ULP1 when only ULP1 sources are set up and
> ULP0 in the other cases. This will greatly help the user. Also, what I'm suggesting
> actually allows to change the ULP1 sources at runtime from devices that are
> actually used which is quite better than setting them up statically from DT.
> 

In the ULP1 mode, all clocks are disabled. It can get lower consumption and
quicker wake up (the processor restarts in less than 10us) than ULP0 mode.

The number of wake up sources is limited as well. It is very different from ULP0's


Hi Nicolas, what is your opinions?


Best Regards,
Wenyou Yang