| Message ID | 1359891126-21909-1-git-send-email-andrew@lunn.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Andrew, On Sun, Feb 03, 2013 at 12:32:06PM +0100, Andrew Lunn wrote: > The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the > driver clk_prepare_enable() this clock, otherwise there is a danger > the SoC will lockup when accessing RTC registers with the clock > disabled. > > Reported-by: Simon Baatz gmbnomis@gmail.com > Signed-off-by: Andrew Lunn <andrew@lunn.ch> And: Tested-by: Simon Baatz <gmbnomis@gmail.com> Btw, <...> is missing from the email address in the Reported-by line. Thanks for providing this so quickly. Now, it looks like this (without applying the GPIO fix, yet, because it would already enable the runit clock): # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count 0 # insmod ./rtc-mv.ko # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count 1 # hwclock Sun Feb 3 19:34:53 2013 -1.003522 seconds # rmmod rtc-mv # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count 0 - Simon
On Sun, Feb 03, 2013 at 08:44:07PM +0100, Simon Baatz wrote: > Hi Andrew, > > On Sun, Feb 03, 2013 at 12:32:06PM +0100, Andrew Lunn wrote: > > The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the > > driver clk_prepare_enable() this clock, otherwise there is a danger > > the SoC will lockup when accessing RTC registers with the clock > > disabled. > > > > Reported-by: Simon Baatz gmbnomis@gmail.com > > Signed-off-by: Andrew Lunn <andrew@lunn.ch> > > And: > > Tested-by: Simon Baatz <gmbnomis@gmail.com> > > Btw, <...> is missing from the email address in the Reported-by line. I'll clean that up. no need for a new version. > Thanks for providing this so quickly. Now, it looks like this > (without applying the GPIO fix, yet, because it would already enable > the runit clock): > > # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count > 0 > # insmod ./rtc-mv.ko > # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count > 1 > # hwclock > Sun Feb 3 19:34:53 2013 -1.003522 seconds > # rmmod rtc-mv > # cat /sys/kernel/debug/clk/tclk/runit/clk_enable_count > 0 Great! Thanks for turning around those tests so quickly. thx, Jason.
On Sun, Feb 03, 2013 at 12:32:06PM +0100, Andrew Lunn wrote: > The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the > driver clk_prepare_enable() this clock, otherwise there is a danger > the SoC will lockup when accessing RTC registers with the clock > disabled. > > Reported-by: Simon Baatz gmbnomis@gmail.com > Signed-off-by: Andrew Lunn <andrew@lunn.ch> > --- > > Since v1: > Enable clock before accessing RTC registers. > > arch/arm/boot/dts/kirkwood.dtsi | 1 + > drivers/rtc/rtc-mv.c | 28 ++++++++++++++++++++++++---- > 2 files changed, 25 insertions(+), 4 deletions(-) Applied to mvebu/fixes with Simon's Tested-by: and added '<' '>' to the Reported-by:. thx, Jason.
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi index 6c5d75f..c57b9c6 100644 --- a/arch/arm/boot/dts/kirkwood.dtsi +++ b/arch/arm/boot/dts/kirkwood.dtsi @@ -77,6 +77,7 @@ compatible = "marvell,kirkwood-rtc", "marvell,orion-rtc"; reg = <0x10300 0x20>; interrupts = <53>; + clocks = <&gate_clk 7>; }; spi@10600 { diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c index 57233c8..8f87fec 100644 --- a/drivers/rtc/rtc-mv.c +++ b/drivers/rtc/rtc-mv.c @@ -14,6 +14,7 @@ #include <linux/platform_device.h> #include <linux/of.h> #include <linux/delay.h> +#include <linux/clk.h> #include <linux/gfp.h> #include <linux/module.h> @@ -41,6 +42,7 @@ struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; int irq; + struct clk *clk; }; static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm) @@ -221,6 +223,7 @@ static int mv_rtc_probe(struct platform_device *pdev) struct rtc_plat_data *pdata; resource_size_t size; u32 rtc_time; + int ret = 0; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) @@ -239,11 +242,17 @@ static int mv_rtc_probe(struct platform_device *pdev) if (!pdata->ioaddr) return -ENOMEM; + pdata->clk = devm_clk_get(&pdev->dev, NULL); + /* Not all SoCs require a clock.*/ + if (!IS_ERR(pdata->clk)) + clk_prepare_enable(pdata->clk); + /* make sure the 24 hours mode is enabled */ rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); if (rtc_time & RTC_HOURS_12H_MODE) { dev_err(&pdev->dev, "24 Hours mode not supported.\n"); - return -EINVAL; + ret = -EINVAL; + goto out; } /* make sure it is actually functional */ @@ -252,7 +261,8 @@ static int mv_rtc_probe(struct platform_device *pdev) rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS); if (rtc_time == 0x01000000) { dev_err(&pdev->dev, "internal RTC not ticking\n"); - return -ENODEV; + ret = -ENODEV; + goto out; } } @@ -268,8 +278,10 @@ static int mv_rtc_probe(struct platform_device *pdev) } else pdata->rtc = rtc_device_register(pdev->name, &pdev->dev, &mv_rtc_ops, THIS_MODULE); - if (IS_ERR(pdata->rtc)) - return PTR_ERR(pdata->rtc); + if (IS_ERR(pdata->rtc)) { + ret = PTR_ERR(pdata->rtc); + goto out; + } if (pdata->irq >= 0) { writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS); @@ -282,6 +294,11 @@ static int mv_rtc_probe(struct platform_device *pdev) } return 0; +out: + if (!IS_ERR(pdata->clk)) + clk_disable_unprepare(pdata->clk); + + return ret; } static int __exit mv_rtc_remove(struct platform_device *pdev) @@ -292,6 +309,9 @@ static int __exit mv_rtc_remove(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 0); rtc_device_unregister(pdata->rtc); + if (!IS_ERR(pdata->clk)) + clk_disable_unprepare(pdata->clk); + return 0; }
The Marvell RTC on Kirkwood makes use of the runit clock. Ensure the driver clk_prepare_enable() this clock, otherwise there is a danger the SoC will lockup when accessing RTC registers with the clock disabled. Reported-by: Simon Baatz gmbnomis@gmail.com Signed-off-by: Andrew Lunn <andrew@lunn.ch> --- Since v1: Enable clock before accessing RTC registers. arch/arm/boot/dts/kirkwood.dtsi | 1 + drivers/rtc/rtc-mv.c | 28 ++++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-)