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

Hans Ulli Kroll
2015-05-12T16:57:17Z

Driver for the on chip RTC found on Cortina's SoC Gemini.

Signed-off-by: Hans Ulli Kroll <ulli.kroll@googlemail.com>
---
MAINTAINERS | 3 +-
drivers/rtc/Kconfig | 10 +++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-gemini.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 204 insertions(+), 1 deletion(-)
create mode 100644 drivers/rtc/rtc-gemini.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 1622775..2e91f68 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -975,9 +975,10 @@ S: Maintained
ARM/CORTINA SYSTEMS GEMINI ARM ARCHITECTURE
M: Hans Ulli Kroll <ulli.kroll@googlemail.com>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
-T: git git://git.berlios.de/gemini-board
+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@kernel.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 6149ae0..99cbce0 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1362,6 +1362,16 @@ 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
+ 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 c31731c..0fd6e22 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -64,6 +64,7 @@ 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..d5763ad
--- /dev/null
+++ b/drivers/rtc/rtc-gemini.c
@@ -0,0 +1,191 @@
+/*
+ * Gemini OnChip RTC
+ *
+ * Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
+ *
+ * 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 form Stormlinksemi
+ * first update from Janos Laube for > 2.6.29 kernels
+ *
+ * checkpatch fixes and usage off rtc-lib code
+ * Hans Ulli Kroll <ulli.kroll@googlemail.com>
+ */
+
+#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>
+#include <mach/hardware.h>
+
+#define DRV_NAME "rtc-gemini"
+#define DRV_VERSION "0.2"
+
+MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
+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 = kzalloc(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 (unlikely(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