[PATCH 3/3] drivers/rtc/rtc-snvs: Add clock support

From: Sanchayan Maity
Date: Fri Sep 26 2014 - 09:14:37 EST


This patch adds clock enable and disable support
for the SNVS peripheral which is required by the
SNVS RTC.

Signed-off-by: Sanchayan Maity <maitysanchayan@xxxxxxxxx>
---
drivers/rtc/rtc-snvs.c | 48 +++++++++++++++++++++++++++++++++++++++---------
1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index fa384fe..f3e8f05 100644
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -17,6 +17,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
+#include <linux/clk.h>

/* These register offsets are relative to LP (Low Power) range */
#define SNVS_LPCR 0x04
@@ -39,6 +40,7 @@ struct snvs_rtc_data {
void __iomem *ioaddr;
int irq;
spinlock_t lock;
+ struct clk *clk;
};

static u32 rtc_read_lp_counter(void __iomem *ioaddr)
@@ -260,8 +262,31 @@ static int snvs_rtc_probe(struct platform_device *pdev)
if (data->irq < 0)
return data->irq;

+ ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
+ IRQF_SHARED, "rtc alarm", &pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq %d: %d\n",
+ data->irq, ret);
+ return ret;
+ }
+
+ data->clk = devm_clk_get(&pdev->dev, "snvs");
+ if (IS_ERR(data->clk)) {
+ dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
+ PTR_ERR(data->clk));
+ ret = PTR_ERR(data->clk);
+ return ret;
+ }
+
platform_set_drvdata(pdev, data);

+ ret = clk_prepare_enable(data->clk);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Could not prepare or enable the snvs clock\n");
+ return ret;
+ }
+
spin_lock_init(&data->lock);

/* Initialize glitch detect */
@@ -275,23 +300,20 @@ static int snvs_rtc_probe(struct platform_device *pdev)

device_init_wakeup(&pdev->dev, true);

- ret = devm_request_irq(&pdev->dev, data->irq, snvs_rtc_irq_handler,
- IRQF_SHARED, "rtc alarm", &pdev->dev);
- if (ret) {
- dev_err(&pdev->dev, "failed to request irq %d: %d\n",
- data->irq, ret);
- return ret;
- }
-
data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&snvs_rtc_ops, THIS_MODULE);
if (IS_ERR(data->rtc)) {
ret = PTR_ERR(data->rtc);
dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
- return ret;
+ goto error_rtc_device_register;
}

return 0;
+
+error_rtc_device_register:
+ clk_disable_unprepare(data->clk);
+
+ return ret;
}

#ifdef CONFIG_PM_SLEEP
@@ -302,16 +324,24 @@ static int snvs_rtc_suspend(struct device *dev)
if (device_may_wakeup(dev))
enable_irq_wake(data->irq);

+ clk_disable_unprepare(data->clk);
+
return 0;
}

static int snvs_rtc_resume(struct device *dev)
{
+ int ret;
+
struct snvs_rtc_data *data = dev_get_drvdata(dev);

if (device_may_wakeup(dev))
disable_irq_wake(data->irq);

+ ret = clk_prepare_enable(data->clk);
+ if (ret)
+ return ret;
+
return 0;
}
#endif
--
1.7.9.5

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