diff options
| author | Andrew Lunn <andrew@lunn.ch> | 2013-02-03 12:32:06 +0100 |
|---|---|---|
| committer | Jason Cooper <jason@lakedaemon.net> | 2013-03-08 21:34:41 +0000 |
| commit | 89c58c198b252f2bc20657fdd72a2aea788c435c (patch) | |
| tree | 735d8844993deb5a8d39efb171db8331241ce547 | |
| parent | de88747f514a4e0cca416a8871de2302f4f77790 (diff) | |
| download | linux-89c58c198b252f2bc20657fdd72a2aea788c435c.tar.bz2 | |
rtc: rtc-mv: Add support for clk to avoid lockups
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>
Tested-by: Simon Baatz <gmbnomis@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
| -rw-r--r-- | arch/arm/boot/dts/kirkwood.dtsi | 1 | ||||
| -rw-r--r-- | drivers/rtc/rtc-mv.c | 28 |
2 files changed, 25 insertions, 4 deletions
diff --git a/arch/arm/boot/dts/kirkwood.dtsi b/arch/arm/boot/dts/kirkwood.dtsi index cf8e8926a034..fada7e6d24d8 100644 --- a/arch/arm/boot/dts/kirkwood.dtsi +++ b/arch/arm/boot/dts/kirkwood.dtsi @@ -75,6 +75,7 @@ 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 57233c885998..8f87fec27ce7 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; } |