diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/rtc/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/rtc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rtc/rtc-au1xxx.c | 153 |
3 files changed, 164 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 92c2db64de9c..3b1c7aa93e75 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -638,6 +638,16 @@ config RTC_DRV_AT91SAM9_GPBR will be used. The default of zero is normally OK to use, but on some systems other software needs to use that register. +config RTC_DRV_AU1XXX + tristate "Au1xxx Counter0 RTC support" + depends on SOC_AU1X00 + help + This is a driver for the Au1xxx on-chip Counter0 (Time-Of-Year + counter) to be used as a RTC. + + This driver can also be built as a module. If so, the module + will be called rtc-au1xxx. + config RTC_DRV_BFIN tristate "Blackfin On-Chip RTC" depends on BLACKFIN && !BF561 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index eef9e337f202..fca0c9bf11c9 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -20,6 +20,7 @@ rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o obj-$(CONFIG_RTC_DRV_AT32AP700X)+= rtc-at32ap700x.o obj-$(CONFIG_RTC_DRV_AT91RM9200)+= rtc-at91rm9200.o obj-$(CONFIG_RTC_DRV_AT91SAM9) += rtc-at91sam9.o +obj-$(CONFIG_RTC_DRV_AU1XXX) += rtc-au1xxx.o obj-$(CONFIG_RTC_DRV_BFIN) += rtc-bfin.o obj-$(CONFIG_RTC_DRV_CMOS) += rtc-cmos.o obj-$(CONFIG_RTC_DRV_DS1216) += rtc-ds1216.o diff --git a/drivers/rtc/rtc-au1xxx.c b/drivers/rtc/rtc-au1xxx.c new file mode 100644 index 000000000000..8906a688e6a6 --- /dev/null +++ b/drivers/rtc/rtc-au1xxx.c @@ -0,0 +1,153 @@ +/* + * Au1xxx counter0 (aka Time-Of-Year counter) RTC interface driver. + * + * Copyright (C) 2008 Manuel Lauss <mano@roarinelk.homelinux.net> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +/* All current Au1xxx SoCs have 2 counters fed by an external 32.768 kHz + * crystal. Counter 0, which keeps counting during sleep/powerdown, is + * used to count seconds since the beginning of the unix epoch. + * + * The counters must be configured and enabled by bootloader/board code; + * no checks as to whether they really get a proper 32.768kHz clock are + * made as this would take far too long. + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <asm/mach-au1x00/au1000.h> + +/* 32kHz clock enabled and detected */ +#define CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S) + +static int au1xtoy_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long t; + + t = au_readl(SYS_TOYREAD); + + rtc_time_to_tm(t, tm); + + return rtc_valid_tm(tm); +} + +static int au1xtoy_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long t; + + rtc_tm_to_time(tm, &t); + + au_writel(t, SYS_TOYWRITE); + au_sync(); + + /* wait for the pending register write to succeed. This can + * take up to 6 seconds... + */ + while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S) + msleep(1); + + return 0; +} + +static struct rtc_class_ops au1xtoy_rtc_ops = { + .read_time = au1xtoy_rtc_read_time, + .set_time = au1xtoy_rtc_set_time, +}; + +static int __devinit au1xtoy_rtc_probe(struct platform_device *pdev) +{ + struct rtc_device *rtcdev; + unsigned long t; + int ret; + + t = au_readl(SYS_COUNTER_CNTRL); + if (!(t & CNTR_OK)) { + dev_err(&pdev->dev, "counters not working; aborting.\n"); + ret = -ENODEV; + goto out_err; + } + + ret = -ETIMEDOUT; + + /* set counter0 tickrate to 1Hz if necessary */ + if (au_readl(SYS_TOYTRIM) != 32767) { + /* wait until hardware gives access to TRIM register */ + t = 0x00100000; + while ((au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T0S) && t--) + msleep(1); + + if (!t) { + /* timed out waiting for register access; assume + * counters are unusable. + */ + dev_err(&pdev->dev, "timeout waiting for access\n"); + goto out_err; + } + + /* set 1Hz TOY tick rate */ + au_writel(32767, SYS_TOYTRIM); + au_sync(); + } + + /* wait until the hardware allows writes to the counter reg */ + while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S) + msleep(1); + + rtcdev = rtc_device_register("rtc-au1xxx", &pdev->dev, + &au1xtoy_rtc_ops, THIS_MODULE); + if (IS_ERR(rtcdev)) { + ret = PTR_ERR(rtcdev); + goto out_err; + } + + platform_set_drvdata(pdev, rtcdev); + + return 0; + +out_err: + return ret; +} + +static int __devexit au1xtoy_rtc_remove(struct platform_device *pdev) +{ + struct rtc_device *rtcdev = platform_get_drvdata(pdev); + + rtc_device_unregister(rtcdev); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static struct platform_driver au1xrtc_driver = { + .driver = { + .name = "rtc-au1xxx", + .owner = THIS_MODULE, + }, + .remove = __devexit_p(au1xtoy_rtc_remove), +}; + +static int __init au1xtoy_rtc_init(void) +{ + return platform_driver_probe(&au1xrtc_driver, au1xtoy_rtc_probe); +} + +static void __exit au1xtoy_rtc_exit(void) +{ + platform_driver_unregister(&au1xrtc_driver); +} + +module_init(au1xtoy_rtc_init); +module_exit(au1xtoy_rtc_exit); + +MODULE_DESCRIPTION("Au1xxx TOY-counter-based RTC driver"); +MODULE_AUTHOR("Manuel Lauss <manuel.lauss@gmail.com>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:rtc-au1xxx"); |