Re: [PATCHv 1/1] RTC:driver for Cortina's SOC

From: Alexandre Belloni
Date: Sat May 30 2015 - 17:48:49 EST


Hi,

On 20/05/2015 at 17:49:31 +0200, Hans Ulli Kroll wrote :
> Driver for the on chip RTC found on Cortina's SoC Gemini.
>
> Signed-off-by: Hans Ulli Kroll <ulli.kroll@xxxxxxxxxxxxxx>

I've applied it with a few modifications:
https://git.kernel.org/cgit/linux/kernel/git/abelloni/linux.git/commit/?h=rtc-next&id=a0928c40a908d18f06c05c9db4bdc8e3f0761179

I've removed the need for goto and labels by using devm_request_irq().

> ---
> MAINTAINERS | 1 +
> drivers/rtc/Kconfig | 11 +++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-gemini.c | 190 +++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 203 insertions(+)
> create mode 100644 drivers/rtc/rtc-gemini.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f0d922b..3cff87e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -977,6 +977,7 @@ L: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
> T: git git://github.com/ulli-kroll/linux.git
> S: Maintained
> F: arch/arm/mach-gemini/
> +F: drivers/rtc/rtc-gemini.c
>
> ARM/CSR SIRFPRIMA2 MACHINE SUPPORT
> M: Barry Song <baohua@xxxxxxxxxx>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 0fe4ad8..4a37931 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -1372,6 +1372,17 @@ config RTC_DRV_ARMADA38X
> This driver can also be built as a module. If so, the module
> will be called armada38x-rtc.
>
> +config RTC_DRV_GEMINI
> + tristate "Gemini SoC RTC"
> + depends on ARCH_GEMINI || COMPILE_TEST
> + depends on HAS_IOMEM
> + help
> + If you say Y here you will get support for the
> + RTC found on Gemini SoC's.
> +
> + This driver can also be built as a module. If so, the module
> + will be called rtc-gemini.
> +
> config RTC_DRV_PS3
> tristate "PS3 RTC"
> depends on PPC_PS3
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 2b82e2b..ed4057a 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -65,6 +65,7 @@ obj-$(CONFIG_RTC_DRV_EFI) += rtc-efi.o
> obj-$(CONFIG_RTC_DRV_EM3027) += rtc-em3027.o
> obj-$(CONFIG_RTC_DRV_EP93XX) += rtc-ep93xx.o
> obj-$(CONFIG_RTC_DRV_FM3130) += rtc-fm3130.o
> +obj-$(CONFIG_RTC_DRV_GEMINI) += rtc-gemini.o
> obj-$(CONFIG_RTC_DRV_GENERIC) += rtc-generic.o
> obj-$(CONFIG_RTC_DRV_HID_SENSOR_TIME) += rtc-hid-sensor-time.o
> obj-$(CONFIG_RTC_DRV_HYM8563) += rtc-hym8563.o
> diff --git a/drivers/rtc/rtc-gemini.c b/drivers/rtc/rtc-gemini.c
> new file mode 100644
> index 0000000..5b36450
> --- /dev/null
> +++ b/drivers/rtc/rtc-gemini.c
> @@ -0,0 +1,190 @@
> +/*
> + * Gemini OnChip RTC
> + *
> + * Copyright (C) 2009 Janos Laube <janos.dev@xxxxxxxxx>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Original code for older kernel 2.6.15 are from Stormlinksemi
> + * first update from Janos Laube for > 2.6.29 kernels
> + *
> + * checkpatch fixes and usage of rtc-lib code
> + * Hans Ulli Kroll <ulli.kroll@xxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/rtc.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#define DRV_NAME "rtc-gemini"
> +#define DRV_VERSION "0.2"
> +
> +MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("RTC driver for Gemini SoC");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRV_NAME);
> +
> +struct gemini_rtc {
> + struct rtc_device *rtc_dev;
> + void __iomem *rtc_base;
> + int rtc_irq;
> +};
> +
> +enum gemini_rtc_offsets {
> + GEMINI_RTC_SECOND = 0x00,
> + GEMINI_RTC_MINUTE = 0x04,
> + GEMINI_RTC_HOUR = 0x08,
> + GEMINI_RTC_DAYS = 0x0C,
> + GEMINI_RTC_ALARM_SECOND = 0x10,
> + GEMINI_RTC_ALARM_MINUTE = 0x14,
> + GEMINI_RTC_ALARM_HOUR = 0x18,
> + GEMINI_RTC_RECORD = 0x1C,
> + GEMINI_RTC_CR = 0x20
> +};
> +
> +static irqreturn_t gemini_rtc_interrupt(int irq, void *dev)
> +{
> + return IRQ_HANDLED;
> +}
> +
> +/*
> + * Looks like the RTC in the Gemini SoC is (totaly) broken
> + * We can't read/write directly the time from RTC registers.
> + * We must do some "offset" calculation to get the real time
> + *
> + * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
> + * the same thing, without the rtc-lib.c calls.
> + */
> +
> +static int gemini_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct gemini_rtc *rtc = dev_get_drvdata(dev);
> +
> + unsigned int days, hour, min, sec;
> + unsigned long offset, time;
> +
> + sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND);
> + min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE);
> + hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR);
> + days = readl(rtc->rtc_base + GEMINI_RTC_DAYS);
> + offset = readl(rtc->rtc_base + GEMINI_RTC_RECORD);
> +
> + time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
> +
> + rtc_time_to_tm(time, tm);
> +
> + return 0;
> +}
> +
> +static int gemini_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct gemini_rtc *rtc = dev_get_drvdata(dev);
> + unsigned int sec, min, hour, day;
> + unsigned long offset, time;
> +
> + if (tm->tm_year >= 2148) /* EPOCH Year + 179 */
> + return -EINVAL;
> +
> + rtc_tm_to_time(tm, &time);
> +
> + sec = readl(rtc->rtc_base + GEMINI_RTC_SECOND);
> + min = readl(rtc->rtc_base + GEMINI_RTC_MINUTE);
> + hour = readl(rtc->rtc_base + GEMINI_RTC_HOUR);
> + day = readl(rtc->rtc_base + GEMINI_RTC_DAYS);
> +
> + offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);
> +
> + writel(offset, rtc->rtc_base + GEMINI_RTC_RECORD);
> + writel(0x01, rtc->rtc_base + GEMINI_RTC_CR);
> +
> + return 0;
> +}
> +
> +static struct rtc_class_ops gemini_rtc_ops = {
> + .read_time = gemini_rtc_read_time,
> + .set_time = gemini_rtc_set_time,
> +};
> +
> +static int gemini_rtc_probe(struct platform_device *pdev)
> +{
> + struct gemini_rtc *rtc;
> + struct device *dev = &pdev->dev;
> + struct resource *res;
> + int ret;
> +
> + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
> + if (unlikely(!rtc))
> + return -ENOMEM;
> + platform_set_drvdata(pdev, rtc);
> +
> + res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!res) {
> + ret = -ENODEV;
> + goto err_mem;
> + }
> + rtc->rtc_irq = res->start;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + ret = -ENODEV;
> + goto err_mem;
> + }
> + rtc->rtc_base = devm_ioremap(&pdev->dev, res->start,
> + res->end - res->start + 1);
> +
> + ret = request_irq(rtc->rtc_irq, gemini_rtc_interrupt,
> + IRQF_SHARED, pdev->name, dev);
> + if (unlikely(ret))
> + goto err_mem;
> +
> + rtc->rtc_dev = rtc_device_register(pdev->name, dev,
> + &gemini_rtc_ops, THIS_MODULE);
> + if (likely(IS_ERR(rtc->rtc_dev))) {
> + ret = PTR_ERR(rtc->rtc_dev);
> + goto err_irq;
> + }
> + return 0;
> +
> +err_irq:
> + free_irq(rtc->rtc_irq, dev);
> +
> +err_mem:
> + kfree(rtc);
> + return ret;
> +}
> +
> +static int gemini_rtc_remove(struct platform_device *pdev)
> +{
> + struct gemini_rtc *rtc = platform_get_drvdata(pdev);
> + struct device *dev = &pdev->dev;
> +
> + free_irq(rtc->rtc_irq, dev);
> + rtc_device_unregister(rtc->rtc_dev);
> + platform_set_drvdata(pdev, NULL);
> + kfree(rtc);
> +
> + return 0;
> +}
> +
> +static struct platform_driver gemini_rtc_driver = {
> + .driver = {
> + .name = DRV_NAME,
> + .owner = THIS_MODULE,
> + },
> + .probe = gemini_rtc_probe,
> + .remove = gemini_rtc_remove,
> +};
> +
> +module_platform_driver_probe(gemini_rtc_driver, gemini_rtc_probe);
> +
> --
> 2.4.0
>

--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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