diff mbox

[19/23] power/reset: at91-poweroff: get and use slow clock

Message ID 1438335599-3301-20-git-send-email-alexandre.belloni@free-electrons.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Alexandre Belloni July 31, 2015, 9:39 a.m. UTC 
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>
---
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: linux-pm@vger.kernel.org
 drivers/power/reset/at91-poweroff.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Sebastian Reichel Aug. 5, 2015, 6:22 p.m. UTC | #1 
Hi,

On Fri, Jul 31, 2015 at 11:39:55AM +0200, Alexandre Belloni wrote:
> 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.

You call clk_prepare_enable during probe without a matching
clk_disable_unprepare on module removal.

-- Sebastian
diff mbox

Patch

diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index 9847cfb7e23d..fadd1a41729b 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 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 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)