Am 2014-09-28 05:56, schrieb Shawn Guo:
> On Fri, Sep 26, 2014 at 06:44:01PM +0530, Sanchayan Maity wrote:
>> This patch adds clock enable and disable support
>> for the SNVS peripheral which is required by the
>> SNVS RTC.
>>
>> Signed-off-by: Sanchayan Maity <maitysancha...@gmail.com>
>> ---
>> 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;
>> + }
>
> No. This will break all i.MX6 devices running a DTB without clock
> definition.
>
Shawn, do you know how this works in i.MX6? Is there no clock gating for
that module or is that clock just missing as of now?
But then, I guess even there is a clock on i.MX6 too, we would still
need to make the clock optional.
--
Stefan
>> +
>> 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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