On 2014-12-03 06:58, Sanchayan Maity wrote:
> This patch adds clock enable and disable support for
> the SNVS peripheral, which is required for using the
> RTC within the SNVS block.
>
> The clock is not strictly enforced, as this would
> break the i.MX devices. The clocking for the i.MX
> devices seems to be enabled elsewhere and enabling
> RTC SNVS for Vybrid results in a crash. This patch
> adds the clock support but also makes it optional
> so Vybrid platform can use the clock if defined
> while making sure not to break i.MX .
>
> Signed-off-by: Sanchayan Maity <maitysancha...@gmail.com>
> ---
> drivers/rtc/rtc-snvs.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
> index fa384fe..d4a6512 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)
> @@ -260,6 +262,18 @@ static int snvs_rtc_probe(struct platform_device *pdev)
> if (data->irq < 0)
> return data->irq;
>
> + data->clk = devm_clk_get(&pdev->dev, "snvs-rtc");
> + if (IS_ERR(data->clk)) {
> + data->clk = NULL;
> + } else {
> + ret = clk_prepare_enable(data->clk);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "Could not prepare or enable the snvs clock\n");
> + return ret;
> + }
> + }
> +
> platform_set_drvdata(pdev, data);
>
> spin_lock_init(&data->lock);
> @@ -280,7 +294,7 @@ static int snvs_rtc_probe(struct platform_device *pdev)
> if (ret) {
> dev_err(&pdev->dev, "failed to request irq %d: %d\n",
> data->irq, ret);
> - return ret;
> + goto error_rtc_device_register;
> }
>
> data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
> @@ -288,10 +302,16 @@ static int snvs_rtc_probe(struct platform_device *pdev)
> 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:
> + if (data->clk)
> + clk_disable_unprepare(data->clk);
> +
> + return ret;
> }
>
> #ifdef CONFIG_PM_SLEEP
> @@ -302,16 +322,26 @@ static int snvs_rtc_suspend(struct device *dev)
> if (device_may_wakeup(dev))
> enable_irq_wake(data->irq);
>
> + if (data->clk)
> + clk_disable_unprepare(data->clk);
> +
> return 0;
> }
>
> static int snvs_rtc_resume(struct device *dev)
> {
> struct snvs_rtc_data *data = dev_get_drvdata(dev);
> + int ret;
>
> if (device_may_wakeup(dev))
> disable_irq_wake(data->irq);
>
> + if (data->clk) {
> + ret = clk_prepare_enable(data->clk);
> + if (ret)
> + return ret;
> + }
> +
> return 0;
> }
> #endif
Acked-by: Stefan Agner <ste...@agner.ch>
--
Stefan
--
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