ARM: at91: pm: add ULP1 support for SAM9X60

Add ULP1 support for SAM9X60. In pm_suspend.S enable RC oscillator in
PMC if it is not enabled. At resume the state before suspend is
restored.

Signed-off-by: Claudiu Beznea <[email protected]>
Acked-by: Stephen Boyd <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
Signed-off-by: Ludovic Desroches <[email protected]>

Author: claudiubeznea

arch/arm/mach-at91/pm.c

@@ -100,6 +100,8 @@ static const struct wakeup_source_info ws_info[] = {
 	{ .pmc_fsmr_bit = AT91_PMC_RTCAL,	.shdwc_mr_bit = BIT(17) },
 	{ .pmc_fsmr_bit = AT91_PMC_USBAL },
 	{ .pmc_fsmr_bit = AT91_PMC_SDMMC_CD },
+	{ .pmc_fsmr_bit = AT91_PMC_RTTAL },
+	{ .pmc_fsmr_bit = AT91_PMC_RXLP_MCE },
 };
 
 static const struct of_device_id sama5d2_ws_ids[] = {
@@ -114,6 +116,17 @@ static const struct of_device_id sama5d2_ws_ids[] = {
 	{ /* sentinel */ }
 };
 
+static const struct of_device_id sam9x60_ws_ids[] = {
+	{ .compatible = "atmel,at91sam9x5-rtc",		.data = &ws_info[1] },
+	{ .compatible = "atmel,at91rm9200-ohci",	.data = &ws_info[2] },
+	{ .compatible = "usb-ohci",			.data = &ws_info[2] },
+	{ .compatible = "atmel,at91sam9g45-ehci",	.data = &ws_info[2] },
+	{ .compatible = "usb-ehci",			.data = &ws_info[2] },
+	{ .compatible = "atmel,at91sam9260-rtt",	.data = &ws_info[4] },
+	{ .compatible = "cdns,sam9x60-macb",		.data = &ws_info[5] },
+	{ /* sentinel */ }
+};
+
 static int at91_pm_config_ws(unsigned int pm_mode, bool set)
 {
 	const struct wakeup_source_info *wsi;
@@ -192,6 +205,13 @@ static int at91_sama5d2_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
 	return 0;
 }
 
+static int at91_sam9x60_config_pmc_ws(void __iomem *pmc, u32 mode, u32 polarity)
+{
+	writel(mode, pmc + AT91_PMC_FSMR);
+
+	return 0;
+}
+
 /*
  * Called after processes are frozen, but before we shutdown devices.
  */
@@ -789,8 +809,12 @@ void __init sam9x60_pm_init(void)
 	if (!IS_ENABLED(CONFIG_SOC_AT91SAM9))
 		return;
 
+	at91_pm_modes_init();
 	at91_dt_ramc();
 	at91_pm_init(at91sam9x60_idle);
+
+	soc_pm.ws_ids = sam9x60_ws_ids;
+	soc_pm.config_pmc_ws = at91_sam9x60_config_pmc_ws;
 }
 
 void __init at91sam9_pm_init(void)

arch/arm/mach-at91/pm_suspend.S

@@ -197,8 +197,26 @@ ENDPROC(at91_backup_mode)
 .macro at91_pm_ulp1_mode
 	ldr	pmc, .pmc_base
 
-	/* Switch the main clock source to 12-MHz RC oscillator */
+	/* Save RC oscillator state and check if it is enabled. */
+	ldr	tmp1, [pmc, #AT91_PMC_SR]
+	str	tmp1, .saved_osc_status
+	tst	tmp1, #AT91_PMC_MOSCRCS
+	bne	2f
+
+	/* Enable RC oscillator */
 	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	orr	tmp1, tmp1, #AT91_PMC_MOSCRCEN
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	/* Wait main RC stabilization */
+1:	ldr	tmp1, [pmc, #AT91_PMC_SR]
+	tst	tmp1, #AT91_PMC_MOSCRCS
+	beq	1b
+
+	/* Switch the main clock source to 12-MHz RC oscillator */
+2:	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
@@ -262,6 +280,25 @@ ENDPROC(at91_backup_mode)
 	str	tmp1, [pmc, #AT91_PMC_MCKR]
 
 	wait_mckrdy
+
+	/* Restore RC oscillator state */
+	ldr	tmp1, .saved_osc_status
+	tst	tmp1, #AT91_PMC_MOSCRCS
+	bne	3f
+
+	/* Disable RC oscillator */
+	ldr	tmp1, [pmc, #AT91_CKGR_MOR]
+	bic	tmp1, tmp1, #AT91_PMC_MOSCRCEN
+	bic	tmp1, tmp1, #AT91_PMC_KEY_MASK
+	orr	tmp1, tmp1, #AT91_PMC_KEY
+	str	tmp1, [pmc, #AT91_CKGR_MOR]
+
+	/* Wait RC oscillator disable done */
+4:	ldr	tmp1, [pmc, #AT91_PMC_SR]
+	tst	tmp1, #AT91_PMC_MOSCRCS
+	bne	4b
+
+3:
 .endm
 
 ENTRY(at91_ulp_mode)
@@ -475,6 +512,8 @@ ENDPROC(at91_sramc_self_refresh)
 	.word 0
 .saved_sam9_mdr1:
 	.word 0
+.saved_osc_status:
+	.word 0
 
 ENTRY(at91_pm_suspend_in_sram_sz)
 	.word .-at91_pm_suspend_in_sram

include/linux/clk/at91_pmc.h

@@ -159,6 +159,7 @@
 
 #define AT91_PMC_FSMR		0x70		/* Fast Startup Mode Register */
 #define AT91_PMC_FSTT(n)	BIT(n)
+#define AT91_PMC_RTTAL		BIT(16)
 #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 */