[PATCH V1] MIPS: Add RTC support for loongson1B

[PATCH V1] MIPS: Add RTC support for loongson1B

[zhzhl555]

From: zhao zhang <zhzhl555@gmail.com>

V1: replace __raw_writel/__raw_readl with writel/readl.
thanks for Linus Wallei's advice.
This patch adds RTC support(TOY counter0) for loongson1B.

Signed-off-by: zhao zhang <zhzhl555@gmail.com>
---
 drivers/rtc/Kconfig    |   10 ++
 drivers/rtc/Makefile   |    1 +
 drivers/rtc/rtc-ls1x.c |  213 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 224 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/rtc-ls1x.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 5a538fc..6f8c2d7 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1070,4 +1070,14 @@ config RTC_DRV_PUV3
 	  This drive can also be built as a module. If so, the module
 	  will be called rtc-puv3.
 
+config RTC_DRV_LOONGSON1
+	tristate "loongson1 RTC support"
+	depends on MACH_LOONGSON1
+	help
+	  This is a driver for the loongson1 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-ls1x.
+
 endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 6e69823..48153fe 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -109,3 +109,4 @@ obj-$(CONFIG_RTC_DRV_VT8500)	+= rtc-vt8500.o
 obj-$(CONFIG_RTC_DRV_WM831X)	+= rtc-wm831x.o
 obj-$(CONFIG_RTC_DRV_WM8350)	+= rtc-wm8350.o
 obj-$(CONFIG_RTC_DRV_X1205)	+= rtc-x1205.o
+obj-$(CONFIG_RTC_DRV_LOONGSON1)	+= rtc-ls1x.o
diff --git a/drivers/rtc/rtc-ls1x.c b/drivers/rtc/rtc-ls1x.c
new file mode 100644
index 0000000..c752a30
--- /dev/null
+++ b/drivers/rtc/rtc-ls1x.c
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2011 Zhao Zhang <zhzhl555@gmail.com>
+ *
+ * Derived from driver/rtc/rtc-au1xxx.c
+ *
+ * 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;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/io.h>
+#include <asm/mach-loongson1/loongson1.h>
+
+#define LS1X_RTC_REG_OFFSET	(LS1X_RTC_BASE + 0x20)
+#define LS1X_RTC_REGS(x) \
+		((void __iomem *)KSEG1ADDR(LS1X_RTC_REG_OFFSET + (x)))
+
+/*RTC programmable counters 0 and 1*/
+#define SYS_COUNTER_CNTRL		(LS1X_RTC_REGS(0x20))
+#define SYS_CNTRL_ERS			(1 << 23)
+#define SYS_CNTRL_RTS			(1 << 20)
+#define SYS_CNTRL_RM2			(1 << 19)
+#define SYS_CNTRL_RM1			(1 << 18)
+#define SYS_CNTRL_RM0			(1 << 17)
+#define SYS_CNTRL_RS			(1 << 16)
+#define SYS_CNTRL_BP			(1 << 14)
+#define SYS_CNTRL_REN			(1 << 13)
+#define SYS_CNTRL_BRT			(1 << 12)
+#define SYS_CNTRL_TEN			(1 << 11)
+#define SYS_CNTRL_BTT			(1 << 10)
+#define SYS_CNTRL_E0			(1 << 8)
+#define SYS_CNTRL_ETS			(1 << 7)
+#define SYS_CNTRL_32S			(1 << 5)
+#define SYS_CNTRL_TTS			(1 << 4)
+#define SYS_CNTRL_TM2			(1 << 3)
+#define SYS_CNTRL_TM1			(1 << 2)
+#define SYS_CNTRL_TM0			(1 << 1)
+#define SYS_CNTRL_TS			(1 << 0)
+
+/* Programmable Counter 0 Registers */
+#define SYS_TOYTRIM		(LS1X_RTC_REGS(0))
+#define SYS_TOYWRITE0		(LS1X_RTC_REGS(4))
+#define SYS_TOYWRITE1		(LS1X_RTC_REGS(8))
+#define SYS_TOYREAD0		(LS1X_RTC_REGS(0xC))
+#define SYS_TOYREAD1		(LS1X_RTC_REGS(0x10))
+#define SYS_TOYMATCH0		(LS1X_RTC_REGS(0x14))
+#define SYS_TOYMATCH1		(LS1X_RTC_REGS(0x18))
+#define SYS_TOYMATCH2		(LS1X_RTC_REGS(0x1C))
+
+/* Programmable Counter 1 Registers */
+#define SYS_RTCTRIM		(LS1X_RTC_REGS(0x40))
+#define SYS_RTCWRITE0		(LS1X_RTC_REGS(0x44))
+#define SYS_RTCREAD0		(LS1X_RTC_REGS(0x48))
+#define SYS_RTCMATCH0		(LS1X_RTC_REGS(0x4C))
+#define SYS_RTCMATCH1		(LS1X_RTC_REGS(0x50))
+#define SYS_RTCMATCH2		(LS1X_RTC_REGS(0x54))
+
+#define LS1X_SEC_OFFSET		(4)
+#define LS1X_MIN_OFFSET		(10)
+#define LS1X_HOUR_OFFSET	(16)
+#define LS1X_DAY_OFFSET		(21)
+#define LS1X_MONTH_OFFSET	(26)
+
+
+#define LS1X_SEC_MASK		(0x3f)
+#define LS1X_MIN_MASK		(0x3f)
+#define LS1X_HOUR_MASK		(0x1f)
+#define LS1X_DAY_MASK		(0x1f)
+#define LS1X_MONTH_MASK		(0x3f)
+#define LS1X_YEAR_MASK		(0xffffffff)
+
+#define ls1x_get_sec(t)		(((t) >> LS1X_SEC_OFFSET) & LS1X_SEC_MASK)
+#define ls1x_get_min(t)		(((t) >> LS1X_MIN_OFFSET) & LS1X_MIN_MASK)
+#define ls1x_get_hour(t)	(((t) >> LS1X_HOUR_OFFSET) & LS1X_HOUR_MASK)
+#define ls1x_get_day(t)		(((t) >> LS1X_DAY_OFFSET) & LS1X_DAY_MASK)
+#define ls1x_get_month(t)	(((t) >> LS1X_MONTH_OFFSET) & LS1X_MONTH_MASK)
+
+#define RTC_CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S)
+
+static int ls1x_rtc_read_time(struct device *dev, struct rtc_time *rtm)
+{
+	unsigned long v, t;
+
+	v = readl(SYS_TOYREAD0);
+	t = readl(SYS_TOYREAD1);
+
+	memset(rtm, 0, sizeof(struct rtc_time));
+	t  = mktime((t & LS1X_YEAR_MASK), ls1x_get_month(v),
+			ls1x_get_day(v), ls1x_get_hour(v),
+			ls1x_get_min(v), ls1x_get_sec(v));
+	rtc_time_to_tm(t, rtm);
+
+	return rtc_valid_tm(rtm);
+}
+
+static int ls1x_rtc_set_time(struct device *dev, struct  rtc_time *rtm)
+{
+	unsigned long v, t;
+
+	v = ((rtm->tm_mon + 1)  << LS1X_MONTH_OFFSET)
+		| (rtm->tm_mday << LS1X_DAY_OFFSET)
+		| (rtm->tm_hour << LS1X_HOUR_OFFSET)
+		| (rtm->tm_min  << LS1X_MIN_OFFSET)
+		| (rtm->tm_sec  << LS1X_SEC_OFFSET);
+
+	t = rtm->tm_year + 1900;
+	writel(v, SYS_TOYWRITE0);
+	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS)
+		usleep_range(1000, 3000);
+	__asm__ volatile ("sync");
+
+	writel(t, SYS_TOYWRITE1);
+	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS)
+		usleep_range(1000, 3000);
+	__asm__ volatile ("sync");
+
+	v = readl(SYS_COUNTER_CNTRL);
+	return 0;
+}
+
+static struct rtc_class_ops  ls1x_rtc_ops = {
+	.read_time	= ls1x_rtc_read_time,
+	.set_time	= ls1x_rtc_set_time,
+};
+
+static int __devinit ls1x_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtcdev;
+	unsigned long v;
+	int ret;
+
+	v = readl(SYS_COUNTER_CNTRL);
+	if (!(v & RTC_CNTR_OK)) {
+		dev_err(&pdev->dev, "rtc counters not working\n");
+		ret = -ENODEV;
+		goto err;
+	}
+	ret = -ETIMEDOUT;
+	/*set to 1 HZ if needed*/
+	if (readl(SYS_TOYTRIM) != 32767) {
+		v = 0x100000;
+		while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS) && --v)
+			usleep_range(1000, 3000);
+
+		if (!v) {
+			dev_err(&pdev->dev, "time out\n");
+			goto err;
+		}
+		writel(32767, SYS_TOYTRIM);
+		__asm__ volatile("sync");
+	}
+	/*this loop coundn't be endless*/
+	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS)
+		usleep_range(1000, 3000);
+
+	rtcdev = rtc_device_register("ls1x-rtc", &pdev->dev,
+					&ls1x_rtc_ops , THIS_MODULE);
+	if (IS_ERR(rtcdev)) {
+		ret = PTR_ERR(rtcdev);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, rtcdev);
+	return 0;
+err:
+	return ret;
+}
+
+static int __devexit ls1x_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  ls1x_rtc_driver = {
+	.driver		= {
+		.name	= "ls1x-rtc",
+		.owner	= THIS_MODULE,
+	},
+	.remove		= __devexit_p(ls1x_rtc_remove),
+};
+
+static int __init ls1x_rtc_init(void)
+{
+	return platform_driver_probe(&ls1x_rtc_driver, ls1x_rtc_probe);
+}
+
+static void __exit ls1x_rtc_exit(void)
+{
+	platform_driver_unregister(&ls1x_rtc_driver);
+}
+
+
+module_init(ls1x_rtc_init);
+module_exit(ls1x_rtc_exit);
+
+
+MODULE_DESCRIPTION("LOONGSON1 TOY-counter-based RTC driver");
+MODULE_AUTHOR("zhao zhang <zhzhl555@gmail.com>");
+MODULE_LICENSE("GPL");
+
-- 
1.7.0.4

Re: [rtc-linux] [PATCH V1] MIPS: Add RTC support for loongson1B

[Wolfram Sang]

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On Fri, Nov 25, 2011 at 10:52:07AM +0800, zhzhl555@gmail.com wrote:
> From: zhao zhang <zhzhl555@gmail.com>
> 
> V1: replace __raw_writel/__raw_readl with writel/readl.
> thanks for Linus Wallei's advice.
> This patch adds RTC support(TOY counter0) for loongson1B.
> 
> Signed-off-by: zhao zhang <zhzhl555@gmail.com>
> ---

Grepping says that rtc-au1xxx.c also has registers with the same name.
Has it been checked if those drivers can be merged/reused?

Regards,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [rtc-linux] [PATCH V1] MIPS: Add RTC support for loongson1B

[Wolfram Sang]

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On Fri, Nov 25, 2011 at 05:49:04PM +0800, zhao zhang wrote:
>    I have checked carefully,
>    1:the au1xx used one register but loongon1B used two 32bit registers
>    (write0/write1 and read0/read1) to represent time.
>    2:the data organization are also different. 
>    so, it's hard to reuse.

Fair enough, thanks for checking.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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Re: [rtc-linux] [PATCH V1] MIPS: Add RTC support for loongson1B

[Wolfram Sang]

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On Fri, Nov 25, 2011 at 10:52:07AM +0800, zhzhl555@gmail.com wrote:

> +	writel(t, SYS_TOYWRITE1);
> +	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TS)
> +		usleep_range(1000, 3000);
> +	__asm__ volatile ("sync");

Timeout?

> +
> +static int __devinit ls1x_rtc_probe(struct platform_device *pdev)
> +{
> +	struct rtc_device *rtcdev;
> +	unsigned long v;
> +	int ret;
> +
> +	v = readl(SYS_COUNTER_CNTRL);
> +	if (!(v & RTC_CNTR_OK)) {
> +		dev_err(&pdev->dev, "rtc counters not working\n");
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +	ret = -ETIMEDOUT;

Why not putting this line to the corresponding dev_err-block?

> +	/*set to 1 HZ if needed*/

Minor: Spaces around comment-markers, here and in other places

/* Comment */

> +	if (readl(SYS_TOYTRIM) != 32767) {
> +		v = 0x100000;
> +		while ((readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS) && --v)
> +			usleep_range(1000, 3000);

Timeout?

> +
> +		if (!v) {
> +			dev_err(&pdev->dev, "time out\n");
> +			goto err;
> +		}
> +		writel(32767, SYS_TOYTRIM);
> +		__asm__ volatile("sync");
> +	}
> +	/*this loop coundn't be endless*/
> +	while (readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_TTS)
> +		usleep_range(1000, 3000);

Timeout again. First, the comment does not help. Why are you sure the loop
could not be endless? And: Does it really need to be a usleep_range() instead
of a simple msleep()? And to make sure: There is no interrupt signalling the
status changed?

> +
> +	rtcdev = rtc_device_register("ls1x-rtc", &pdev->dev,
> +					&ls1x_rtc_ops , THIS_MODULE);
> +	if (IS_ERR(rtcdev)) {
> +		ret = PTR_ERR(rtcdev);
> +		goto err;
> +	}
> +
> +	platform_set_drvdata(pdev, rtcdev);
> +	return 0;
> +err:
> +	return ret;
> +}
> +

...

> +static int __init ls1x_rtc_init(void)
> +{
> +	return platform_driver_probe(&ls1x_rtc_driver, ls1x_rtc_probe);
> +}
> +
> +static void __exit ls1x_rtc_exit(void)
> +{
> +	platform_driver_unregister(&ls1x_rtc_driver);
> +}
> +
> +
> +module_init(ls1x_rtc_init);
> +module_exit(ls1x_rtc_exit);

Please use the new module_platform_driver()-macro.

Thanks,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

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