power/reset: at91-poweroff: get and use slow clock
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>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
diff --git a/drivers/power/reset/at91-poweroff.c b/drivers/power/reset/at91-poweroff.c
index 3e698d9..e9e24df 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 void __iomem *at91_shdwc_base;
+static struct clk *sclk;
static void __init at91_wakeup_status(void)
{
@@ -122,6 +124,7 @@
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 @@
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 @@
if (pm_power_off == at91_poweroff)
pm_power_off = NULL;
+ clk_disable_unprepare(sclk);
+
return 0;
}
