[PATCH 0/6] shutdown procedure verification for SAMA5D2

[PATCH 0/6] shutdown procedure verification for SAMA5D2

[Claudiu Beznea]

Hi,

Patch 1 from this series implement a fix for shutdown procedure
for SAMA5D2.

The rest of the patch are improvements as follows:
patch 2 - use only one function for poweroff
patches 3-6 - cosmetic improvements

The patches are based on latest sys-reset/for-next [1].

Thank you,
Claudiu Beznea

[1] https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git

Claudiu Beznea (6):
  power: reset: at91-poweroff: switch to slow clock before shutdown
  power: reset: at91-poweroff: use only one poweroff function
  power: reset: at91-poweroff: make mpddrc_base part of struct shdwc
  power: reset: at91-poweroff: make sclk part of struct shdwc
  power: reset: at91-poweroff: rename at91_shdwc_base member of struct
    shdwc
  power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

 arch/arm/mach-at91/pm_suspend.S          |   8 +++
 drivers/power/reset/at91-sama5d2_shdwc.c | 119 +++++++++++++++++++++----------
 2 files changed, 88 insertions(+), 39 deletions(-)

-- 
2.7.4

[PATCH 1/6] power: reset: at91-poweroff: switch to slow clock before shutdown

[Claudiu Beznea]

The SAMA5D2 NRST input signal is resynchronized with the SLCK clock and it
can take up to 2 SLCK cycles (about 90us) for the internal reset to be
effective. During this delay, the VDDCORE current consumption may still be
high (application-dependent) with the VDDCORE regulator already OFF. Under
such conditions, VDDCORE may operate below its operating range leading to
potential register corruption.

To prevent such situation, it is recommended to decrease significantly the
power consumption of the device once the voltage regulator is  turned-off.
This can be achieved by operating the device at a much lower low frequency.

To solve this switch the master clock to slock clock just before writing
shutdown command to shutdown controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Suggested-by: Patrice Vilchez <patrice.vilchez@microchip.com>
---
 arch/arm/mach-at91/pm_suspend.S          |  8 ++++
 drivers/power/reset/at91-sama5d2_shdwc.c | 66 ++++++++++++++++++++++++++++----
 2 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index a7c6ae13c945..bfe1c4d06901 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -149,6 +149,14 @@ exit_suspend:
 ENDPROC(at91_pm_suspend_in_sram)
 
 ENTRY(at91_backup_mode)
+	/* Switch the master clock source to slow clock. */
+	ldr	pmc, .pmc_base
+	ldr	tmp1, [pmc, #AT91_PMC_MCKR]
+	bic	tmp1, tmp1, #AT91_PMC_CSS
+	str	tmp1, [pmc, #AT91_PMC_MCKR]
+
+	wait_mckrdy
+
 	/*BUMEN*/
 	ldr	r0, .sfr
 	mov	tmp1, #0x1
diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index 0206cce328b3..dd6297bd7b6a 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -19,6 +19,7 @@
  */
 
 #include <linux/clk.h>
+#include <linux/clk/at91_pmc.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -70,6 +71,7 @@ struct shdwc_config {
 struct shdwc {
 	const struct shdwc_config *cfg;
 	void __iomem *at91_shdwc_base;
+	void __iomem *pmc_base;
 };
 
 /*
@@ -108,6 +110,12 @@ static void __init at91_wakeup_status(struct platform_device *pdev)
 
 static void at91_poweroff(void)
 {
+	/* Switch the master clock source to slow clock. */
+	writel(readl(at91_shdwc->pmc_base + AT91_PMC_MCKR) & ~AT91_PMC_CSS,
+	       at91_shdwc->pmc_base + AT91_PMC_MCKR);
+	while (!(readl(at91_shdwc->pmc_base + AT91_PMC_SR) & AT91_PMC_MCKRDY))
+		;
+
 	writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
 	       at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
 }
@@ -123,6 +131,16 @@ static void at91_lpddr_poweroff(void)
 
 		/* Power down SDRAM0 */
 		"	str	%1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
+
+		/* Switch the master clock source to slow clock. */
+		"	ldr	r6, [%4, #" __stringify(AT91_PMC_MCKR) "]\n\t"
+		"	bic	r6, r6,  #" __stringify(AT91_PMC_CSS) "\n\t"
+		"	str	r6, [%4, #" __stringify(AT91_PMC_MCKR) "]\n\t"
+		/* Wait for clock switch. */
+		"1:	ldr	r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t"
+		"	tst	r6, #"	    __stringify(AT91_PMC_MCKRDY) "\n\t"
+		"	beq	1b\n\t"
+
 		/* Shutdown CPU */
 		"	str	%3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
 
@@ -131,7 +149,8 @@ static void at91_lpddr_poweroff(void)
 		: "r" (mpddrc_base),
 		  "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
 		  "r" (at91_shdwc->at91_shdwc_base),
-		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW)
+		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW),
+		  "r" (at91_shdwc->pmc_base)
 		: "r6");
 }
 
@@ -276,26 +295,53 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 
 	at91_shdwc_dt_configure(pdev);
 
-	pm_power_off = at91_poweroff;
+	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-pmc");
+	if (!np) {
+		ret = -ENODEV;
+		goto clk_disable;
+	}
+
+	at91_shdwc->pmc_base = of_iomap(np, 0);
+	of_node_put(np);
+
+	if (!at91_shdwc->pmc_base) {
+		ret = -ENOMEM;
+		goto clk_disable;
+	}
 
 	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc");
-	if (!np)
-		return 0;
+	if (!np) {
+		ret = -ENODEV;
+		goto unmap;
+	}
 
 	mpddrc_base = of_iomap(np, 0);
 	of_node_put(np);
 
-	if (!mpddrc_base)
-		return 0;
+	if (!mpddrc_base) {
+		ret = -ENOMEM;
+		goto unmap;
+	}
+
+	pm_power_off = at91_poweroff;
 
 	ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
 	if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) ||
-	    (ddr_type == AT91_DDRSDRC_MD_LPDDR3))
+	    (ddr_type == AT91_DDRSDRC_MD_LPDDR3)) {
 		pm_power_off = at91_lpddr_poweroff;
-	else
+	} else {
 		iounmap(mpddrc_base);
+		mpddrc_base = NULL;
+	}
 
 	return 0;
+
+unmap:
+	iounmap(at91_shdwc->pmc_base);
+clk_disable:
+	clk_disable_unprepare(sclk);
+
+	return ret;
 }
 
 static int __exit at91_shdwc_remove(struct platform_device *pdev)
@@ -310,6 +356,10 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
 	writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR);
 	writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
 
+	if (mpddrc_base)
+		iounmap(mpddrc_base);
+	iounmap(shdw->pmc_base);
+
 	clk_disable_unprepare(sclk);
 
 	return 0;
-- 
2.7.4

[PATCH 2/6] power: reset: at91-poweroff: use only one poweroff function

[Claudiu Beznea]

Use only one poweroff function for sama5d2 and adapt it to work for both
scenarios (having LPDDR or not).

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index dd6297bd7b6a..94ad79d0d82e 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -110,18 +110,6 @@ static void __init at91_wakeup_status(struct platform_device *pdev)
 
 static void at91_poweroff(void)
 {
-	/* Switch the master clock source to slow clock. */
-	writel(readl(at91_shdwc->pmc_base + AT91_PMC_MCKR) & ~AT91_PMC_CSS,
-	       at91_shdwc->pmc_base + AT91_PMC_MCKR);
-	while (!(readl(at91_shdwc->pmc_base + AT91_PMC_SR) & AT91_PMC_MCKRDY))
-		;
-
-	writel(AT91_SHDW_KEY | AT91_SHDW_SHDW,
-	       at91_shdwc->at91_shdwc_base + AT91_SHDW_CR);
-}
-
-static void at91_lpddr_poweroff(void)
-{
 	asm volatile(
 		/* Align to cache lines */
 		".balign 32\n\t"
@@ -130,16 +118,18 @@ static void at91_lpddr_poweroff(void)
 		"	ldr	r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
 
 		/* Power down SDRAM0 */
+		"	tst	%0, #0\n\t"
+		"	beq	1f\n\t"
 		"	str	%1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
 
 		/* Switch the master clock source to slow clock. */
-		"	ldr	r6, [%4, #" __stringify(AT91_PMC_MCKR) "]\n\t"
+		"1:	ldr	r6, [%4, #" __stringify(AT91_PMC_MCKR) "]\n\t"
 		"	bic	r6, r6,  #" __stringify(AT91_PMC_CSS) "\n\t"
 		"	str	r6, [%4, #" __stringify(AT91_PMC_MCKR) "]\n\t"
 		/* Wait for clock switch. */
-		"1:	ldr	r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t"
+		"2:	ldr	r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t"
 		"	tst	r6, #"	    __stringify(AT91_PMC_MCKRDY) "\n\t"
-		"	beq	1b\n\t"
+		"	beq	2b\n\t"
 
 		/* Shutdown CPU */
 		"	str	%3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
@@ -326,10 +316,8 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 	pm_power_off = at91_poweroff;
 
 	ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
-	if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) ||
-	    (ddr_type == AT91_DDRSDRC_MD_LPDDR3)) {
-		pm_power_off = at91_lpddr_poweroff;
-	} else {
+	if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
+	    ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
 		iounmap(mpddrc_base);
 		mpddrc_base = NULL;
 	}
@@ -348,8 +336,7 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
 {
 	struct shdwc *shdw = platform_get_drvdata(pdev);
 
-	if (pm_power_off == at91_poweroff ||
-	    pm_power_off == at91_lpddr_poweroff)
+	if (pm_power_off == at91_poweroff)
 		pm_power_off = NULL;
 
 	/* Reset values to disable wake-up features  */
-- 
2.7.4

[PATCH 3/6] power: reset: at91-poweroff: make mpddrc_base part of struct shdwc

[Claudiu Beznea]

Make mpddrc_base part of struct shdwc since there is also only one
instance of struct shdwc *at91_shdwc in system and to have all data
specific to SHDWC grouped together.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index 94ad79d0d82e..c9994103248e 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -71,6 +71,7 @@ struct shdwc_config {
 struct shdwc {
 	const struct shdwc_config *cfg;
 	void __iomem *at91_shdwc_base;
+	void __iomem *mpddrc_base;
 	void __iomem *pmc_base;
 };
 
@@ -80,7 +81,6 @@ struct shdwc {
  */
 static struct shdwc *at91_shdwc;
 static struct clk *sclk;
-static void __iomem *mpddrc_base;
 
 static const unsigned long long sdwc_dbc_period[] = {
 	0, 3, 32, 512, 4096, 32768,
@@ -136,7 +136,7 @@ static void at91_poweroff(void)
 
 		"	b	.\n\t"
 		:
-		: "r" (mpddrc_base),
+		: "r" (at91_shdwc->mpddrc_base),
 		  "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
 		  "r" (at91_shdwc->at91_shdwc_base),
 		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW),
@@ -305,21 +305,22 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 		goto unmap;
 	}
 
-	mpddrc_base = of_iomap(np, 0);
+	at91_shdwc->mpddrc_base = of_iomap(np, 0);
 	of_node_put(np);
 
-	if (!mpddrc_base) {
+	if (!at91_shdwc->mpddrc_base) {
 		ret = -ENOMEM;
 		goto unmap;
 	}
 
 	pm_power_off = at91_poweroff;
 
-	ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD;
+	ddr_type = readl(at91_shdwc->mpddrc_base + AT91_DDRSDRC_MDR) &
+			 AT91_DDRSDRC_MD;
 	if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
 	    ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
-		iounmap(mpddrc_base);
-		mpddrc_base = NULL;
+		iounmap(at91_shdwc->mpddrc_base);
+		at91_shdwc->mpddrc_base = NULL;
 	}
 
 	return 0;
@@ -343,8 +344,8 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
 	writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR);
 	writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
 
-	if (mpddrc_base)
-		iounmap(mpddrc_base);
+	if (shdw->mpddrc_base)
+		iounmap(shdw->mpddrc_base);
 	iounmap(shdw->pmc_base);
 
 	clk_disable_unprepare(sclk);
-- 
2.7.4

[PATCH 4/6] power: reset: at91-poweroff: make sclk part of struct shdwc

[Claudiu Beznea]

Make sclk part of struct shdwc to have all the data specific to SHDWC
grouped together in one structure.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index c9994103248e..945b41b4086a 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -70,6 +70,7 @@ struct shdwc_config {
 
 struct shdwc {
 	const struct shdwc_config *cfg;
+	struct clk *sclk;
 	void __iomem *at91_shdwc_base;
 	void __iomem *mpddrc_base;
 	void __iomem *pmc_base;
@@ -80,7 +81,6 @@ struct shdwc {
  * since pm_power_off itself is global.
  */
 static struct shdwc *at91_shdwc;
-static struct clk *sclk;
 
 static const unsigned long long sdwc_dbc_period[] = {
 	0, 3, 32, 512, 4096, 32768,
@@ -271,11 +271,11 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 	match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node);
 	at91_shdwc->cfg = match->data;
 
-	sclk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(sclk))
-		return PTR_ERR(sclk);
+	at91_shdwc->sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(at91_shdwc->sclk))
+		return PTR_ERR(at91_shdwc->sclk);
 
-	ret = clk_prepare_enable(sclk);
+	ret = clk_prepare_enable(at91_shdwc->sclk);
 	if (ret) {
 		dev_err(&pdev->dev, "Could not enable slow clock\n");
 		return ret;
@@ -328,7 +328,7 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 unmap:
 	iounmap(at91_shdwc->pmc_base);
 clk_disable:
-	clk_disable_unprepare(sclk);
+	clk_disable_unprepare(at91_shdwc->sclk);
 
 	return ret;
 }
@@ -348,7 +348,7 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
 		iounmap(shdw->mpddrc_base);
 	iounmap(shdw->pmc_base);
 
-	clk_disable_unprepare(sclk);
+	clk_disable_unprepare(shdw->sclk);
 
 	return 0;
 }
-- 
2.7.4

[PATCH 5/6] power: reset: at91-poweroff: rename at91_shdwc_base member of struct shdwc

[Claudiu Beznea]

Rename at91_shdwc_base member of struct shdwc to shdwc_base. There is
already an "at91" string in at91_shdwc object.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index 945b41b4086a..ad6e2796690a 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -71,7 +71,7 @@ struct shdwc_config {
 struct shdwc {
 	const struct shdwc_config *cfg;
 	struct clk *sclk;
-	void __iomem *at91_shdwc_base;
+	void __iomem *shdwc_base;
 	void __iomem *mpddrc_base;
 	void __iomem *pmc_base;
 };
@@ -92,7 +92,7 @@ static void __init at91_wakeup_status(struct platform_device *pdev)
 	u32 reg;
 	char *reason = "unknown";
 
-	reg = readl(shdw->at91_shdwc_base + AT91_SHDW_SR);
+	reg = readl(shdw->shdwc_base + AT91_SHDW_SR);
 
 	dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);
 
@@ -138,7 +138,7 @@ static void at91_poweroff(void)
 		:
 		: "r" (at91_shdwc->mpddrc_base),
 		  "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
-		  "r" (at91_shdwc->at91_shdwc_base),
+		  "r" (at91_shdwc->shdwc_base),
 		  "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW),
 		  "r" (at91_shdwc->pmc_base)
 		: "r6");
@@ -222,10 +222,10 @@ static void at91_shdwc_dt_configure(struct platform_device *pdev)
 		mode |= SHDW_RTCWKEN(shdw->cfg);
 
 	dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode);
-	writel(mode, shdw->at91_shdwc_base + AT91_SHDW_MR);
+	writel(mode, shdw->shdwc_base + AT91_SHDW_MR);
 
 	input = at91_shdwc_get_wakeup_input(pdev, np);
-	writel(input, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
+	writel(input, shdw->shdwc_base + AT91_SHDW_WUIR);
 }
 
 static const struct shdwc_config sama5d2_shdwc_config = {
@@ -262,10 +262,10 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, at91_shdwc);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	at91_shdwc->at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(at91_shdwc->at91_shdwc_base)) {
+	at91_shdwc->shdwc_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(at91_shdwc->shdwc_base)) {
 		dev_err(&pdev->dev, "Could not map reset controller address\n");
-		return PTR_ERR(at91_shdwc->at91_shdwc_base);
+		return PTR_ERR(at91_shdwc->shdwc_base);
 	}
 
 	match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node);
@@ -341,8 +341,8 @@ static int __exit at91_shdwc_remove(struct platform_device *pdev)
 		pm_power_off = NULL;
 
 	/* Reset values to disable wake-up features  */
-	writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR);
-	writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR);
+	writel(0, shdw->shdwc_base + AT91_SHDW_MR);
+	writel(0, shdw->shdwc_base + AT91_SHDW_WUIR);
 
 	if (shdw->mpddrc_base)
 		iounmap(shdw->mpddrc_base);
-- 
2.7.4

[PATCH 6/6] power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

[Claudiu Beznea]

There should be only one instance of struct shdwc in the system. This is
referenced through at91_shdwc. Return in probe if at91_shdwc is already
allocated.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
 drivers/power/reset/at91-sama5d2_shdwc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/power/reset/at91-sama5d2_shdwc.c b/drivers/power/reset/at91-sama5d2_shdwc.c
index ad6e2796690a..2b686c55b717 100644
--- a/drivers/power/reset/at91-sama5d2_shdwc.c
+++ b/drivers/power/reset/at91-sama5d2_shdwc.c
@@ -255,6 +255,9 @@ static int __init at91_shdwc_probe(struct platform_device *pdev)
 	if (!pdev->dev.of_node)
 		return -ENODEV;
 
+	if (at91_shdwc)
+		return -EBUSY;
+
 	at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
 	if (!at91_shdwc)
 		return -ENOMEM;
-- 
2.7.4

Re: [PATCH 0/6] shutdown procedure verification for SAMA5D2

[Nicolas Ferre]

On 30/08/2018 at 13:50, Claudiu Beznea wrote:
> Hi,
> 
> Patch 1 from this series implement a fix for shutdown procedure
> for SAMA5D2.
> 
> The rest of the patch are improvements as follows:
> patch 2 - use only one function for poweroff
> patches 3-6 - cosmetic improvements

For the whole series:
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

> The patches are based on latest sys-reset/for-next [1].
> 
> Thank you,
> Claudiu Beznea
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git
> 
> Claudiu Beznea (6):
>    power: reset: at91-poweroff: switch to slow clock before shutdown
>    power: reset: at91-poweroff: use only one poweroff function
>    power: reset: at91-poweroff: make mpddrc_base part of struct shdwc
>    power: reset: at91-poweroff: make sclk part of struct shdwc
>    power: reset: at91-poweroff: rename at91_shdwc_base member of struct
>      shdwc
>    power: reset: at91-poweroff: do not procede if at91_shdwc is allocated
> 
>   arch/arm/mach-at91/pm_suspend.S          |   8 +++
>   drivers/power/reset/at91-sama5d2_shdwc.c | 119 +++++++++++++++++++++----------
>   2 files changed, 88 insertions(+), 39 deletions(-)
> 


-- 
Nicolas Ferre

Re: [PATCH 0/6] shutdown procedure verification for SAMA5D2

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 1217 bytes --]

Hi,

On Thu, Aug 30, 2018 at 02:50:05PM +0300, Claudiu Beznea wrote:
> Hi,
> 
> Patch 1 from this series implement a fix for shutdown procedure
> for SAMA5D2.
> 
> The rest of the patch are improvements as follows:
> patch 2 - use only one function for poweroff
> patches 3-6 - cosmetic improvements
> 
> The patches are based on latest sys-reset/for-next [1].
> 
> Thank you,
> Claudiu Beznea
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git

Thanks, queued.

-- Sebastian

> 
> Claudiu Beznea (6):
>   power: reset: at91-poweroff: switch to slow clock before shutdown
>   power: reset: at91-poweroff: use only one poweroff function
>   power: reset: at91-poweroff: make mpddrc_base part of struct shdwc
>   power: reset: at91-poweroff: make sclk part of struct shdwc
>   power: reset: at91-poweroff: rename at91_shdwc_base member of struct
>     shdwc
>   power: reset: at91-poweroff: do not procede if at91_shdwc is allocated
> 
>  arch/arm/mach-at91/pm_suspend.S          |   8 +++
>  drivers/power/reset/at91-sama5d2_shdwc.c | 119 +++++++++++++++++++++----------
>  2 files changed, 88 insertions(+), 39 deletions(-)
> 
> -- 
> 2.7.4
> 

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH 0/6] shutdown procedure verification for SAMA5D2

[Sebastian Reichel]

[-- Attachment #1: Type: text/plain, Size: 2232 bytes --]

Hi Nicolas,

On Sun, Sep 16, 2018 at 12:43:01PM +0200, Sebastian Reichel wrote:
> Hi,
> 
> On Thu, Aug 30, 2018 at 02:50:05PM +0300, Claudiu Beznea wrote:
> > Hi,
> > 
> > Patch 1 from this series implement a fix for shutdown procedure
> > for SAMA5D2.
> > 
> > The rest of the patch are improvements as follows:
> > patch 2 - use only one function for poweroff
> > patches 3-6 - cosmetic improvements
> > 
> > The patches are based on latest sys-reset/for-next [1].
> > 
> > Thank you,
> > Claudiu Beznea
> > 
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git
> 
> Thanks, queued.

I merged this via a immutable branch, that you can pull into at91 or
ignore:

The following changes since commit 5b394b2ddf0347bef56e50c69a58773c94343ff3:

  Linux 4.19-rc1 (2018-08-26 14:11:59 -0700)

are available in the Git repository at:

  ssh://git@gitolite.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply.git tags/psy-at91-poweroff-immutable-for-v4.20-signed

for you to fetch changes up to 9f1e44774be578fb92776add95f1fcaf8284d692:

  power: reset: at91-poweroff: do not procede if at91_shdwc is allocated (2018-09-16 12:32:17 +0200)

----------------------------------------------------------------
Immutable branch for mach-at91 and power-supply for v4.20

Immutable branch between mach-at91 and power-supply for driver
changes in at91-poweroff.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

----------------------------------------------------------------
Claudiu Beznea (6):
      power: reset: at91-poweroff: switch to slow clock before shutdown
      power: reset: at91-poweroff: use only one poweroff function
      power: reset: at91-poweroff: make mpddrc_base part of struct shdwc
      power: reset: at91-poweroff: make sclk part of struct shdwc
      power: reset: at91-poweroff: rename at91_shdwc_base member of struct shdwc
      power: reset: at91-poweroff: do not procede if at91_shdwc is allocated

 arch/arm/mach-at91/pm_suspend.S          |   8 +++
 drivers/power/reset/at91-sama5d2_shdwc.c | 119 +++++++++++++++++++++----------
 2 files changed, 88 insertions(+), 39 deletions(-)

-- Sebastian

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]