[PATCH v3 0/5] power/reset: at91: cleanups and slow clock

[PATCH v3 0/5] power/reset: at91: cleanups and slow clock

[Alexandre Belloni]

Hi,

As discussed this series is now removing non DT initialization, allowing to
compile the drivers as modules and finally adding slow clock support to the
drivers.


Alexandre Belloni (5):
  power/reset: at91-reset: remove useless at91_reset_platform_probe()
  power/reset: at91-reset: allow compiling as a module
  power/reset: at91-reset: get and use slow clock
  power/reset: at91-poweroff: allow compiling as a module
  power/reset: at91-poweroff: get and use slow clock

 drivers/power/reset/Kconfig         |  4 +--
 drivers/power/reset/at91-poweroff.c | 33 ++++++++++++++++--
 drivers/power/reset/at91-reset.c    | 67 ++++++++++++++-----------------------
 3 files changed, 58 insertions(+), 46 deletions(-)

-- 
2.1.4

[PATCH v3 1/5] power/reset: at91-reset: remove useless at91_reset_platform_probe()

[Alexandre Belloni]

Since all the at91 platforms are now DT only, at91_reset_platform_probe()
is now useless, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/at91-reset.c | 47 +++-------------------------------------
 1 file changed, 3 insertions(+), 44 deletions(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 36dc52fb2ec8..3225c8590ed0 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -169,11 +169,11 @@ static struct notifier_block at91_restart_nb = {
 	.priority = 192,
 };
 
-static int at91_reset_of_probe(struct platform_device *pdev)
+static int at91_reset_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct device_node *np;
-	int idx = 0;
+	int ret, idx = 0;
 
 	at91_rstc_base = of_iomap(pdev->dev.of_node, 0);
 	if (!at91_rstc_base) {
@@ -192,49 +192,8 @@ static int at91_reset_of_probe(struct platform_device *pdev)
 
 	match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
 	at91_restart_nb.notifier_call = match->data;
-	return register_restart_handler(&at91_restart_nb);
-}
-
-static int at91_reset_platform_probe(struct platform_device *pdev)
-{
-	const struct platform_device_id *match;
-	struct resource *res;
-	int idx = 0;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	at91_rstc_base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(at91_rstc_base)) {
-		dev_err(&pdev->dev, "Could not map reset controller address\n");
-		return PTR_ERR(at91_rstc_base);
-	}
-
-	for (idx = 0; idx < 2; idx++) {
-		res = platform_get_resource(pdev, IORESOURCE_MEM, idx + 1 );
-		at91_ramc_base[idx] = devm_ioremap(&pdev->dev, res->start,
-						   resource_size(res));
-		if (!at91_ramc_base[idx]) {
-			dev_err(&pdev->dev, "Could not map ram controller address\n");
-			return -ENOMEM;
-		}
-	}
-
-	match = platform_get_device_id(pdev);
-	at91_restart_nb.notifier_call =
-		(int (*)(struct notifier_block *,
-			 unsigned long, void *)) match->driver_data;
-
-	return register_restart_handler(&at91_restart_nb);
-}
-
-static int at91_reset_probe(struct platform_device *pdev)
-{
-	int ret;
-
-	if (pdev->dev.of_node)
-		ret = at91_reset_of_probe(pdev);
-	else
-		ret = at91_reset_platform_probe(pdev);
 
+	ret = register_restart_handler(&at91_restart_nb);
 	if (ret)
 		return ret;
 
-- 
2.1.4

[PATCH v3 2/5] power/reset: at91-reset: allow compiling as a module

[Alexandre Belloni]

It was not possible to compile at91-reset as a module. Implement .remove()
to allow it. Also switch to module_platform_driver_probe() as it is not
hotpluggable.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/Kconfig      |  2 +-
 drivers/power/reset/at91-reset.c | 17 ++++++++++++++---
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 17d93a73c513..e41da4a80a05 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -23,7 +23,7 @@ config POWER_RESET_AT91_POWEROFF
 	  SoCs
 
 config POWER_RESET_AT91_RESET
-	bool "Atmel AT91 reset driver"
+	tristate "Atmel AT91 reset driver"
 	depends on ARCH_AT91
 	default SOC_AT91SAM9 || SOC_SAMA5
 	help
diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 3225c8590ed0..120f3dec9574 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -169,7 +169,7 @@ static struct notifier_block at91_restart_nb = {
 	.priority = 192,
 };
 
-static int at91_reset_probe(struct platform_device *pdev)
+static int __init at91_reset_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct device_node *np;
@@ -202,6 +202,13 @@ static int at91_reset_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int __exit at91_reset_remove(struct platform_device *pdev)
+{
+	unregister_restart_handler(&at91_restart_nb);
+
+	return 0;
+}
+
 static const struct platform_device_id at91_reset_plat_match[] = {
 	{ "at91-sam9260-reset", (unsigned long)at91sam9260_restart },
 	{ "at91-sam9g45-reset", (unsigned long)at91sam9g45_restart },
@@ -209,11 +216,15 @@ static const struct platform_device_id at91_reset_plat_match[] = {
 };
 
 static struct platform_driver at91_reset_driver = {
-	.probe = at91_reset_probe,
+	.remove = __exit_p(at91_reset_remove),
 	.driver = {
 		.name = "at91-reset",
 		.of_match_table = at91_reset_of_match,
 	},
 	.id_table = at91_reset_plat_match,
 };
-module_platform_driver(at91_reset_driver);
+module_platform_driver_probe(at91_reset_driver, at91_reset_probe);
+
+MODULE_AUTHOR("Atmel Corporation");
+MODULE_DESCRIPTION("Reset driver for Atmel SoCs");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4

[PATCH v3 3/5] power/reset: at91-reset: get and use slow clock

[Alexandre Belloni]

Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the at91 reset
controller.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/at91-reset.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c
index 120f3dec9574..8f0bcb232149 100644
--- a/drivers/power/reset/at91-reset.c
+++ b/drivers/power/reset/at91-reset.c
@@ -11,6 +11,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -46,6 +47,7 @@ enum reset_type {
 };
 
 static void __iomem *at91_ramc_base[2], *at91_rstc_base;
+static struct clk *sclk;
 
 /*
 * unless the SDRAM is cleanly shutdown before we hit the
@@ -193,9 +195,21 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 	match = of_match_node(at91_reset_of_match, pdev->dev.of_node);
 	at91_restart_nb.notifier_call = match->data;
 
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
 	ret = register_restart_handler(&at91_restart_nb);
-	if (ret)
+	if (ret) {
+		clk_disable_unprepare(sclk);
 		return ret;
+	}
 
 	at91_reset_status(pdev);
 
@@ -205,6 +219,7 @@ static int __init at91_reset_probe(struct platform_device *pdev)
 static int __exit at91_reset_remove(struct platform_device *pdev)
 {
 	unregister_restart_handler(&at91_restart_nb);
+	clk_disable_unprepare(sclk);
 
 	return 0;
 }
-- 
2.1.4

[PATCH v3 4/5] power/reset: at91-poweroff: allow compiling as a module

[Alexandre Belloni]

It was not possible to compile at91-poweroff as a module. Implement
.remove() to allow it. Also switch to module_platform_driver_probe() as it
is not hotpluggable.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/Kconfig         |  2 +-
 drivers/power/reset/at91-poweroff.c | 18 +++++++++++++++---
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index e41da4a80a05..b3c6191d1847 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -15,7 +15,7 @@ config POWER_RESET_AS3722
 	  This driver supports turning off board via a ams AS3722 power-off.
 
 config POWER_RESET_AT91_POWEROFF
-	bool "Atmel AT91 poweroff driver"
+	tristate "Atmel AT91 poweroff driver"
 	depends on ARCH_AT91
 	default SOC_AT91SAM9 || SOC_SAMA5
 	help
diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index 9847cfb7e23d..3e698d916c4f 100644
--- a/drivers/power/reset/at91-poweroff.c
+++ b/drivers/power/reset/at91-poweroff.c
@@ -119,7 +119,7 @@ static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
 	writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR);
 }
 
-static int at91_poweroff_probe(struct platform_device *pdev)
+static int __init at91_poweroff_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 
@@ -140,6 +140,14 @@ static int at91_poweroff_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int __exit at91_poweroff_remove(struct platform_device *pdev)
+{
+	if (pm_power_off == at91_poweroff)
+		pm_power_off = NULL;
+
+	return 0;
+}
+
 static const struct of_device_id at91_poweroff_of_match[] = {
 	{ .compatible = "atmel,at91sam9260-shdwc", },
 	{ .compatible = "atmel,at91sam9rl-shdwc", },
@@ -148,10 +156,14 @@ static const struct of_device_id at91_poweroff_of_match[] = {
 };
 
 static struct platform_driver at91_poweroff_driver = {
-	.probe = at91_poweroff_probe,
+	.remove = __exit_p(at91_poweroff_remove),
 	.driver = {
 		.name = "at91-poweroff",
 		.of_match_table = at91_poweroff_of_match,
 	},
 };
-module_platform_driver(at91_poweroff_driver);
+module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe);
+
+MODULE_AUTHOR("Atmel Corporation");
+MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4

[PATCH v3 5/5] power/reset: at91-poweroff: get and use slow clock

[Alexandre Belloni]

Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the at91 shutdown
controller.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/power/reset/at91-poweroff.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index 3e698d916c4f..e9e24df35f26 100644
--- a/drivers/power/reset/at91-poweroff.c
+++ b/drivers/power/reset/at91-poweroff.c
@@ -10,6 +10,7 @@
  * warranty of any kind, whether express or implied.
  */
 
+#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -48,6 +49,7 @@ static const char *shdwc_wakeup_modes[] = {
 };
 
 static void __iomem *at91_shdwc_base;
+static struct clk *sclk;
 
 static void __init at91_wakeup_status(void)
 {
@@ -122,6 +124,7 @@ static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
 static int __init at91_poweroff_probe(struct platform_device *pdev)
 {
 	struct resource *res;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
@@ -130,6 +133,16 @@ static int __init at91_poweroff_probe(struct platform_device *pdev)
 		return PTR_ERR(at91_shdwc_base);
 	}
 
+	sclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(sclk))
+		return PTR_ERR(sclk);
+
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not enable slow clock\n");
+		return ret;
+	}
+
 	at91_wakeup_status();
 
 	if (pdev->dev.of_node)
@@ -145,6 +158,8 @@ static int __exit at91_poweroff_remove(struct platform_device *pdev)
 	if (pm_power_off == at91_poweroff)
 		pm_power_off = NULL;
 
+	clk_disable_unprepare(sclk);
+
 	return 0;
 }
 
-- 
2.1.4

[PATCH v3 0/5] power/reset: at91: cleanups and slow clock

[Sebastian Reichel]

Hi,

On Tue, Aug 11, 2015 at 11:12:45AM +0200, Alexandre Belloni wrote:
> As discussed this series is now removing non DT initialization, allowing to
> compile the drivers as modules and finally adding slow clock support to the
> drivers.
>
> [...]
>
>   power/reset: at91-reset: remove useless at91_reset_platform_probe()
>   power/reset: at91-reset: allow compiling as a module
>   power/reset: at91-reset: get and use slow clock
>   power/reset: at91-poweroff: allow compiling as a module
>   power/reset: at91-poweroff: get and use slow clock

Thanks, queued for 4.4. You may want to add another patch adding

MODULE_DEVICE_TABLE(of, xxx_of_match);

-- Sebastian
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[PATCH v3 0/5] power/reset: at91: cleanups and slow clock

[Alexandre Belloni]

On 22/09/2015 at 17:13:35 +0200, Sebastian Reichel wrote :
> Thanks, queued for 4.4. You may want to add another patch adding
> 
> MODULE_DEVICE_TABLE(of, xxx_of_match);
> 

Sure, I will do.


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