2009-11-29 12:37:30

by Wan ZongShun

[permalink] [raw]
Subject: [PATCH V4]ARM: NUC900: add RTC driver support for nuc910 and nuc920

Dear Alessandro,

I fixed this patch and submitted it again.

thanks!

signed-off-by: Wan ZongShun <[email protected]>

---
drivers/rtc/Kconfig | 6 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-nuc900.c | 331 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 338 insertions(+), 0 deletions(-)
create mode 100644 drivers/rtc/rtc-nuc900.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 3c20dae..266ce62 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -573,6 +573,12 @@ config RTC_DRV_AB3100
Select this to enable the ST-Ericsson AB3100 Mixed Signal IC RTC
support. This chip contains a battery- and capacitor-backed RTC.

+config RTC_DRV_NUC900
+ tristate "NUC910/NUC920 RTC driver"
+ depends on RTC_CLASS && ARCH_W90X900
+ help
+ If you say yes here you get support for the RTC subsystem of the
+ NUC910/NUC920 used in embedded systems.

comment "on-CPU RTC drivers"

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index aa3fbd5..d511774 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_RTC_MXC) += rtc-mxc.o
obj-$(CONFIG_RTC_DRV_MAX6900) += rtc-max6900.o
obj-$(CONFIG_RTC_DRV_MAX6902) += rtc-max6902.o
obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o
+obj-$(CONFIG_RTC_DRV_NUC900) += rtc-nuc900.o
obj-$(CONFIG_RTC_DRV_OMAP) += rtc-omap.o
obj-$(CONFIG_RTC_DRV_PCAP) += rtc-pcap.o
obj-$(CONFIG_RTC_DRV_PCF8563) += rtc-pcf8563.o
diff --git a/drivers/rtc/rtc-nuc900.c b/drivers/rtc/rtc-nuc900.c
new file mode 100644
index 0000000..6002309
--- /dev/null
+++ b/drivers/rtc/rtc-nuc900.c
@@ -0,0 +1,331 @@
+/*
+ * Copyright (c) 2008-2009 Nuvoton technology corporation.
+ *
+ * Wan ZongShun <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation;version 2 of the License.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/bcd.h>
+
+/* RTC Control Registers */
+#define REG_RTC_INIR 0x00
+#define REG_RTC_AER 0x04
+#define REG_RTC_FCR 0x08
+#define REG_RTC_TLR 0x0C
+#define REG_RTC_CLR 0x10
+#define REG_RTC_TSSR 0x14
+#define REG_RTC_DWR 0x18
+#define REG_RTC_TAR 0x1C
+#define REG_RTC_CAR 0x20
+#define REG_RTC_LIR 0x24
+#define REG_RTC_RIER 0x28
+#define REG_RTC_RIIR 0x2C
+#define REG_RTC_TTR 0x30
+
+#define RTCSET 0x01
+#define AERRWENB 0x10000
+#define INIRRESET 0xa5eb1357
+#define AERPOWERON 0xA965
+#define AERPOWEROFF 0x0000
+#define LEAPYEAR 0x0001
+#define TICKENB 0x80
+#define TICKINTENB 0x0002
+#define ALARMINTENB 0x0001
+#define MODE24 0x0001
+
+struct nuc900_rtc {
+ int irq_num;
+ void __iomem *rtc_reg;
+ struct rtc_device *rtcdev;
+};
+
+struct nuc900_bcd_time {
+ int bcd_sec;
+ int bcd_min;
+ int bcd_hour;
+ int bcd_mday;
+ int bcd_mon;
+ int bcd_year;
+};
+
+static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
+{
+ struct nuc900_rtc *rtc = _rtc;
+ unsigned long events = 0, rtc_irq;
+
+ rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);
+
+ if (rtc_irq & ALARMINTENB) {
+ rtc_irq &= ~ALARMINTENB;
+ __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
+ events |= RTC_AF | RTC_IRQF;
+ }
+
+ if (rtc_irq & TICKINTENB) {
+ rtc_irq &= ~TICKINTENB;
+ __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
+ events |= RTC_UF | RTC_IRQF;
+ }
+
+ rtc_update_irq(rtc->rtcdev, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+static void check_rtc_power(struct nuc900_rtc *nuc900_rtc)
+{
+ unsigned int i;
+ __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
+
+ mdelay(10);
+
+ __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
+
+ for (i = 0; i < 1000000; i++) {
+ if (__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
+ break;
+ }
+}
+
+static void nuc900_rtc_bcd2bin(unsigned int timereg,
+ unsigned int calreg, struct rtc_time *tm)
+{
+ tm->tm_mday = bcd2bin(calreg >> 0);
+ tm->tm_mon = bcd2bin(calreg >> 8);
+ tm->tm_year = bcd2bin(calreg >> 16) + 100;
+
+ tm->tm_sec = bcd2bin(timereg >> 0);
+ tm->tm_min = bcd2bin(timereg >> 8);
+ tm->tm_hour = bcd2bin(timereg >> 16);
+
+ rtc_valid_tm(tm);
+}
+
+static void nuc900_rtc_bin2bcd(struct rtc_time *settm,
+ struct nuc900_bcd_time *gettm)
+{
+ gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
+ gettm->bcd_mon = bin2bcd(settm->tm_mon) << 8;
+ gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
+
+ gettm->bcd_sec = bin2bcd(settm->tm_sec) << 0;
+ gettm->bcd_min = bin2bcd(settm->tm_min) << 8;
+ gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
+}
+
+static int nuc900_update_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+
+ if (enabled)
+ __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
+ (TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
+ else
+ __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
+ (~TICKINTENB), rtc->rtc_reg + REG_RTC_RIER);
+
+ return 0;
+}
+
+static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+
+ if (enabled)
+ __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
+ (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
+ else
+ __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
+ (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
+
+ return 0;
+}
+
+static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+ unsigned int timeval, clrval;
+
+ timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
+ clrval = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
+
+ nuc900_rtc_bcd2bin(timeval, clrval, tm);
+
+ return 0;
+}
+
+static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+ struct nuc900_bcd_time gettm;
+ unsigned long val;
+
+ nuc900_rtc_bin2bcd(tm, &gettm);
+
+ check_rtc_power(rtc);
+
+ val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
+ __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
+
+ val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
+ __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
+
+ return 0;
+}
+
+static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+ unsigned int timeval, carval;
+
+ timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
+ carval = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
+
+ nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
+
+ return 0;
+}
+
+static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct nuc900_rtc *rtc = dev_get_drvdata(dev);
+ struct nuc900_bcd_time tm;
+ unsigned long val;
+
+ nuc900_rtc_bin2bcd(&alrm->time, &tm);
+
+ check_rtc_power(rtc);
+
+ val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
+ __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
+
+ val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
+ __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
+
+ return 0;
+}
+
+static struct rtc_class_ops nuc900_rtc_ops = {
+ .read_time = nuc900_rtc_read_time,
+ .set_time = nuc900_rtc_set_time,
+ .read_alarm = nuc900_rtc_read_alarm,
+ .set_alarm = nuc900_rtc_set_alarm,
+ .alarm_irq_enable = nuc900_alarm_irq_enable,
+ .update_irq_enable = nuc900_update_irq_enable,
+};
+
+static int __devinit nuc900_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct nuc900_rtc *nuc900_rtc;
+ int err = 0;
+
+ nuc900_rtc = kzalloc(sizeof(struct nuc900_rtc), GFP_KERNEL);
+ if (!nuc900_rtc) {
+ dev_err(&pdev->dev, "kzalloc nuc900_rtc failed\n");
+ return -ENOMEM;
+ }
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "platform_get_resource failed\n");
+ err = -ENXIO;
+ goto fail1;
+ }
+
+ if (!request_mem_region(res->start, resource_size(res),
+ pdev->name)) {
+ dev_err(&pdev->dev, "request_mem_region failed\n");
+ err = -EBUSY;
+ goto fail1;
+ }
+
+ nuc900_rtc->rtc_reg = ioremap(res->start, resource_size(res));
+ if (!nuc900_rtc->rtc_reg) {
+ dev_err(&pdev->dev, "ioremap rtc_reg failed\n");
+ err = -ENOMEM;
+ goto fail2;
+ }
+
+ nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
+ if (request_irq(nuc900_rtc->irq_num, nuc900_rtc_interrupt,
+ IRQF_DISABLED, "nuc900rtc", nuc900_rtc)) {
+ dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
+ err = -EBUSY;
+ goto fail3;
+ }
+
+ nuc900_rtc->rtcdev = rtc_device_register(pdev->name, &pdev->dev,
+ &nuc900_rtc_ops, THIS_MODULE);
+ if (IS_ERR(nuc900_rtc->rtcdev)) {
+ dev_err(&pdev->dev, "rtc device register faild\n");
+ err = PTR_ERR(nuc900_rtc->rtcdev);
+ goto fail4;
+ }
+
+ platform_set_drvdata(pdev, nuc900_rtc);
+ __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
+ nuc900_rtc->rtc_reg + REG_RTC_TSSR);
+
+ return 0;
+
+fail4: free_irq(nuc900_rtc->irq_num, nuc900_rtc);
+fail3: iounmap(nuc900_rtc->rtc_reg);
+fail2: release_mem_region(res->start, resource_size(res));
+fail1: kfree(nuc900_rtc);
+ return err;
+}
+
+static int __devexit nuc900_rtc_remove(struct platform_device *pdev)
+{
+ struct nuc900_rtc *nuc900_rtc = platform_get_drvdata(pdev);
+ struct resource *res;
+
+ rtc_device_unregister(nuc900_rtc->rtcdev);
+ free_irq(nuc900_rtc->irq_num, nuc900_rtc);
+ iounmap(nuc900_rtc->rtc_reg);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(res->start, resource_size(res));
+
+ kfree(nuc900_rtc);
+
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static struct platform_driver nuc900_rtc_driver = {
+ .remove = __devexit_p(nuc900_rtc_remove),
+ .driver = {
+ .name = "nuc900-rtc",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init nuc900_rtc_init(void)
+{
+ return platform_driver_probe(&nuc900_rtc_driver, nuc900_rtc_probe);
+}
+
+static void __exit nuc900_rtc_exit(void)
+{
+ platform_driver_unregister(&nuc900_rtc_driver);
+}
+
+module_init(nuc900_rtc_init);
+module_exit(nuc900_rtc_exit);
+
+MODULE_AUTHOR("Wan ZongShun <[email protected]>");
+MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nuc900-rtc");
--
1.5.6.3


2009-11-30 22:23:54

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH V4]ARM: NUC900: add RTC driver support for nuc910 and nuc920

On Sun, 29 Nov 2009 20:37:23 +0800
Wan ZongShun <[email protected]> wrote:

> Dear Alessandro,
>
> I fixed this patch and submitted it again.
>
> thanks!
>
> signed-off-by: Wan ZongShun <[email protected]>

That's not a terribly useful changelog.

>
> ...
>
> +static void check_rtc_power(struct nuc900_rtc *nuc900_rtc)
> +{
> + unsigned int i;
> + __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
> +
> + mdelay(10);
> +
> + __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
> +
> + for (i = 0; i < 1000000; i++) {
> + if (__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
> + break;
> + }
> +}

I don't like that function much.

- It's not obvious what it actually does (I don't know), so it should
have some comment explaining this.

- It's called "check_rtc_power", but it doesn't actually "check"
anything.

- If that enormously expensive loop times out, the function will not
inform the caller of this, so it will be called again and again and
will continue to be enormously expensive.

>
> ...
>