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.
Signed-off-by: Sebastian Andrzej Siewior <[email protected]> CC: [email protected] Signed-off-by: Dirk Brandewie <[email protected]> --- v1 - v2: - changed ctrl_reg & freq_reg to changed ctrl-reg & freq-reg as recommended by Benh - added missing get_rtc_time() - set the default day to 1 - added binding info Documentation/powerpc/dts-bindings/rtc-cmos.txt | 28 ++++++ drivers/rtc/rtc-cmos.c | 108 +++++++++++++++++++++++ 2 files changed, 136 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: + + r...@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..e516a4b 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -36,6 +36,9 @@ #include <linux/platform_device.h> #include <linux/mod_devicetable.h> #include <linux/log2.h> +#include <linux/of.h> +#include <linux/of_address.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> @@ -1120,6 +1123,98 @@ static struct pnp_driver cmos_pnp_driver = { }; #endif /* CONFIG_PNP */ +#ifdef CONFIG_OF +static bool of_driver_registered; + +static const struct of_device_id of_cmos_match[] = { + { + .compatible = "motorola,mc146818", + }, + { }, +}; +MODULE_DEVICE_TABLE(of, of_cmos_match); + +static int __init of_cmos_probe(struct platform_device *dev, + const struct of_device_id *match) +{ + struct resource res; + struct device_node *node = dev->dev.of_node; + struct rtc_time time; + int ret; + int virq; + const __be32 *val; + + ret = of_address_to_resource(node, 0, &res); + if (ret) + return ret; + + virq = irq_of_parse_and_map(node, 0); + + 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); + } + + return cmos_do_probe(&dev->dev, &res, virq); +} + +static int __exit of_cmos_remove(struct platform_device *dev) +{ + cmos_do_remove(&dev->dev); + return 0; +} + +static int of_cmos_shutdown(struct platform_device *dev) +{ + if (system_state == SYSTEM_POWER_OFF && !cmos_poweroff(&dev->dev)) + return 0; + + cmos_do_shutdown(); + return 0; +} + +#ifdef CONFIG_PM +static int of_cmos_suspend(struct platform_device *dev, pm_message_t mesg) +{ + return cmos_suspend(&dev->dev, mesg); +} + +static int of_cmos_resume(struct platform_device *dev) +{ + return cmos_resume(&dev->dev); +} +#else +#define of_cmos_suspend NULL +#define of_cmos_resume NULL +#endif + +static struct of_platform_driver cmos_of_driver_probe = { + .driver = { + .name = "motorola-mc146818", + .owner = THIS_MODULE, + .of_match_table = of_cmos_match, + }, + .probe = of_cmos_probe, + .remove = of_cmos_remove, + .shutdown = of_cmos_shutdown, + .suspend = of_cmos_suspend, + .resume = of_cmos_resume, +}; +#endif + /*----------------------------------------------------------------*/ @@ -1176,6 +1271,11 @@ static int __init cmos_init(void) if (retval == 0) pnp_driver_registered = true; #endif +#ifdef CONFIG_OF + retval = of_register_platform_driver(&cmos_of_driver_probe); + if (retval == 0) + of_driver_registered = true; +#endif if (!cmos_rtc.dev) { retval = platform_driver_probe(&cmos_platform_driver, @@ -1191,6 +1291,10 @@ static int __init cmos_init(void) if (pnp_driver_registered) pnp_unregister_driver(&cmos_pnp_driver); #endif +#ifdef CONFIG_OF + if (of_driver_registered) + of_unregister_platform_driver(&cmos_of_driver_probe); +#endif return retval; } module_init(cmos_init); @@ -1201,6 +1305,10 @@ static void __exit cmos_exit(void) if (pnp_driver_registered) pnp_unregister_driver(&cmos_pnp_driver); #endif +#ifdef CONFIG_OF + if (of_driver_registered) + of_unregister_platform_driver(&cmos_of_driver_probe); +#endif if (platform_driver_registered) platform_driver_unregister(&cmos_platform_driver); } -- 1.7.3.2 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
