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 at91rm9200 rtc.
Signed-off-by: Alexandre Belloni <alexandre.bell...@free-electrons.com>
---
Cc: Alessandro Zummo <a.zu...@towertech.it>
Cc: rtc-li...@googlegroups.com
drivers/rtc/rtc-at91rm9200.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index 35efd3f75b18..8093d9e50619 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -24,6 +24,7 @@
#include <linux/time.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
+#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/ioctl.h>
@@ -59,6 +60,7 @@ static bool suspended;
static DEFINE_SPINLOCK(suspended_lock);
static unsigned long cached_events;
static u32 at91_rtc_imr;
+static struct clk *sclk;
static void at91_rtc_write_ier(u32 mask)
{
@@ -407,6 +409,16 @@ static int __init at91_rtc_probe(struct platform_device
*pdev)
return -ENOMEM;
}
+ 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_rtc_write(AT91_RTC_CR, 0);
at91_rtc_write(AT91_RTC_MR, 0); /* 24 hour mode */
@@ -420,7 +432,7 @@ static int __init at91_rtc_probe(struct platform_device
*pdev)
"at91_rtc", pdev);
if (ret) {
dev_err(&pdev->dev, "IRQ %d already in use.\n", irq);
- return ret;
+ goto err_clk;
}
/* cpu init code should really have flagged this device as
@@ -431,8 +443,10 @@ static int __init at91_rtc_probe(struct platform_device
*pdev)
rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&at91_rtc_ops, THIS_MODULE);
- if (IS_ERR(rtc))
- return PTR_ERR(rtc);
+ if (IS_ERR(rtc)) {
+ ret = PTR_ERR(rtc);
+ goto err_clk;
+ }
platform_set_drvdata(pdev, rtc);
/* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
@@ -442,6 +456,11 @@ static int __init at91_rtc_probe(struct platform_device
*pdev)
dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n");
return 0;
+
+err_clk:
+ clk_disable_unprepare(sclk);
+
+ return ret;
}
/*
@@ -454,6 +473,8 @@ static int __exit at91_rtc_remove(struct platform_device
*pdev)
AT91_RTC_SECEV | AT91_RTC_TIMEV |
AT91_RTC_CALEV);
+ clk_disable_unprepare(sclk);
+
return 0;
}
--
2.1.4
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