Messages in this thread Patch in this message | | | Date | Thu, 13 Jan 2011 11:50:42 +0100 | From | Sebastian Andrzej Siewior <> | Subject | [PATCH v2] rtc/cmos: add OF bindings |
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This allows to load the OF driver based informations from the device tree. Systems without BIOS may need to perform some initialization. PowerPC creates a PNP device from the OF information and performs this kind of initialization in their private PCI quirk. This looks more generic.
Cc: rtc-linux@googlegroups.com Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: devicetree-discuss@lists.ozlabs.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> ---
* Grant Likely | 2011-01-11 17:04:42 [-0700]:
>It's usually cleaner to break the of-specific probe stuff into a >separate function that can be #ifdef'ed out as a whole instead of >having #ifdef blocks inside the probe functions. Aside from that this >patch looks good to me.
Done.
Documentation/powerpc/dts-bindings/rtc-cmos.txt | 28 ++++++++++++++ drivers/rtc/rtc-cmos.c | 46 +++++++++++++++++++++++ 2 files changed, 74 insertions(+), 0 deletions(-) create mode 100644 Documentation/powerpc/dts-bindings/rtc-cmos.txt
diff --git a/Documentation/powerpc/dts-bindings/rtc-cmos.txt b/Documentation/powerpc/dts-bindings/rtc-cmos.txt new file mode 100644 index 0000000..7382989 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/rtc-cmos.txt @@ -0,0 +1,28 @@ + Motorola mc146818 compatible RTC +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Required properties: + - compatible : "motorola,mc146818" + - reg : should contain registers location and length. + +Optional properties: + - interrupts : should contain interrupt. + - interrupt-parent : interrupt source phandle. + - ctrl-reg : Contains the initial value of the control register also + called "Register B". + - freq-reg : Contains the initial value of the frequency register also + called "Regsiter A". + +"Register A" and "B" are usually initialized by the firmware (BIOS for +instance). If this is not done, it can be performed by the driver. + +ISA Example: + + rtc@70 { + compatible = "motorola,mc146818"; + interrupts = <8 3>; + interrupt-parent = <&ioapic1>; + ctrl-reg = <2>; + freq-reg = <0x26>; + reg = <1 0x70 2>; + }; diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index 5856167..95a08dd 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -36,6 +36,8 @@ #include <linux/platform_device.h> #include <linux/mod_devicetable.h> #include <linux/log2.h> +#include <linux/of.h> +#include <linux/of_platform.h> /* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */ #include <asm-generic/rtc.h> @@ -1121,6 +1123,46 @@ static struct pnp_driver cmos_pnp_driver = { #endif /* CONFIG_PNP */ +#ifdef CONFIG_OF +static const struct of_device_id of_cmos_match[] = { + { + .compatible = "motorola,mc146818", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, of_cmos_match); + +static __init void cmos_of_init(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct rtc_time time; + int ret; + const __be32 *val; + + if (!node) + return; + + val = of_get_property(node, "ctrl-reg", NULL); + if (val) + CMOS_WRITE(be32_to_cpup(val), RTC_CONTROL); + + val = of_get_property(node, "freq-reg", NULL); + if (val) + CMOS_WRITE(be32_to_cpup(val), RTC_FREQ_SELECT); + + get_rtc_time(&time); + ret = rtc_valid_tm(&time); + if (ret) { + struct rtc_time def_time = { + .tm_year = 1, + .tm_mday = 1, + }; + set_rtc_time(&def_time); + } +} +#else +static inline void cmos_of_init(struct platform_device *pdev) {} +#endif /*----------------------------------------------------------------*/ /* Platform setup should have set up an RTC device, when PNP is @@ -1129,6 +1171,7 @@ static struct pnp_driver cmos_pnp_driver = { static int __init cmos_platform_probe(struct platform_device *pdev) { + cmos_of_init(pdev); cmos_wake_setup(&pdev->dev); return cmos_do_probe(&pdev->dev, platform_get_resource(pdev, IORESOURCE_IO, 0), @@ -1157,6 +1200,9 @@ static struct platform_driver cmos_platform_driver = { .shutdown = cmos_platform_shutdown, .driver = { .name = (char *) driver_name, +#if defined(CONFIG_OF) + .of_match_table = of_cmos_match, +#endif .suspend = cmos_suspend, .resume = cmos_resume, } -- 1.7.3.2
Sebastian
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