From: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
Add device driver for a virtual Goldfish RTC clock.
The driver can be build only if CONFIG_MIPS and CONFIG_GOLDFISH
are set. The device tree key used by OS for binding the driver is
defined as "google,goldfish-rtc".
Signed-off-by: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
Signed-off-by: Goran Ferenc <goran.ferenc@xxxxxxxxxx>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@xxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/rtc/Kconfig | 6 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-goldfish.c | 149 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 157 insertions(+)
create mode 100644 drivers/rtc/rtc-goldfish.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 519cdef..26a1267 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -845,6 +845,7 @@ ANDROID GOLDFISH RTC DRIVER
M: Miodrag Dinic <miodrag.dinic@xxxxxxxxxx>
S: Supported
F: Documentation/devicetree/bindings/rtc/google,goldfish-rtc.txt
+F: drivers/rtc/rtc-goldfish.c
ANDROID ION DRIVER
M: Laura Abbott <labbott@xxxxxxxxxx>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 8d3b957..510c5b7 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1753,5 +1753,11 @@ config RTC_DRV_HID_SENSOR_TIME
If this driver is compiled as a module, it will be named
rtc-hid-sensor-time.
+config RTC_DRV_GOLDFISH
+ tristate "Goldfish Real Time Clock"
+ depends on MIPS
+ depends on GOLDFISH
+ help
+ Say yes here to build support for the Goldfish RTC.
endif # RTC_CLASS
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 13857d2..dfc38f5 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -168,3 +168,4 @@ obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o
obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
obj-$(CONFIG_RTC_DRV_XGENE) += rtc-xgene.o
obj-$(CONFIG_RTC_DRV_ZYNQMP) += rtc-zynqmp.o
+obj-$(CONFIG_RTC_DRV_GOLDFISH) += rtc-goldfish.o
diff --git a/drivers/rtc/rtc-goldfish.c b/drivers/rtc/rtc-goldfish.c
new file mode 100644
index 0000000..658b723
--- /dev/null
+++ b/drivers/rtc/rtc-goldfish.c
@@ -0,0 +1,149 @@
+/* drivers/rtc/rtc-goldfish.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2017 Imagination Technologies Ltd.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+enum {
+ TIMER_TIME_LOW = 0x00, /* get low bits of current time */
+ /* and update TIMER_TIME_HIGH */
+ TIMER_TIME_HIGH = 0x04, /* get high bits of time at last */
+ /* TIMER_TIME_LOW read */
+ TIMER_ALARM_LOW = 0x08, /* set low bits of alarm and */
+ /* activate it */
+ TIMER_ALARM_HIGH = 0x0c, /* set high bits of next alarm */
+ TIMER_CLEAR_INTERRUPT = 0x10,
+ TIMER_CLEAR_ALARM = 0x14
+};
+
+struct goldfish_rtc {
+ void __iomem *base;
+ uint32_t irq;
+ struct rtc_device *rtc;
+};
+
+static irqreturn_t
+goldfish_rtc_interrupt(int irq, void *dev_id)
+{
+ struct goldfish_rtc *qrtc = dev_id;
+ unsigned long events = 0;
+ void __iomem *base = qrtc->base;
+
+ writel(1, base + TIMER_CLEAR_INTERRUPT);
+ events = RTC_IRQF | RTC_AF;
+
+ rtc_update_irq(qrtc->rtc, 1, events);
+
+ return IRQ_HANDLED;
+}
+
+static int goldfish_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ uint64_t time;
+ uint64_t time_low;
+ uint64_t time_high;
+ uint64_t time_high_prev;
+ struct goldfish_rtc *qrtc =
+ platform_get_drvdata(to_platform_device(dev));
+ void __iomem *base = qrtc->base;
+
+ time_high = readl(base + TIMER_TIME_HIGH);
+ do {
+ time_high_prev = time_high;
+ time_low = readl(base + TIMER_TIME_LOW);
+ time_high = readl(base + TIMER_TIME_HIGH);
+ } while (time_high != time_high_prev);
+ time = ((int64_t)time_high << 32) | time_low;
+
+ do_div(time, NSEC_PER_SEC);
+
+ rtc_time_to_tm(time, tm);
+ return 0;
+}
+
+static const struct rtc_class_ops goldfish_rtc_ops = {
+ .read_time = goldfish_rtc_read_time,
+};
+
+static int goldfish_rtc_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct resource *r;
+ struct goldfish_rtc *qrtc;
+ unsigned long rtc_dev_len;
+ unsigned long rtc_dev_addr;
+
+ qrtc = devm_kzalloc(&pdev->dev, sizeof(*qrtc), GFP_KERNEL);
+ if (qrtc == NULL) {
+ ret = -ENOMEM;
+ goto error;
+ }
+ platform_set_drvdata(pdev, qrtc);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (r == NULL) {
+ ret = -ENODEV;
+ goto error;
+ }
+
+ rtc_dev_addr = r->start;
+ rtc_dev_len = resource_size(r);
+ qrtc->base = devm_ioremap(&pdev->dev, rtc_dev_addr, rtc_dev_len);
+ if (IS_ERR(qrtc->base)) {
+ ret = -ENODEV;
+ goto error;
+ }
+
+ qrtc->irq = platform_get_irq(pdev, 0);
+ if (qrtc->irq < 0) {
+ ret = -ENODEV;
+ goto error;
+ }
+
+ qrtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &goldfish_rtc_ops, THIS_MODULE);
+ if (IS_ERR(qrtc->rtc)) {
+ ret = PTR_ERR(qrtc->rtc);
+ goto error;
+ }
+
+ ret = devm_request_irq(&pdev->dev, qrtc->irq, goldfish_rtc_interrupt,
+ 0, pdev->name, qrtc);
+ if (ret)
+ goto error;
+
+ return 0;
+
+error:
+ return ret;
+}
+
+static const struct of_device_id goldfish_rtc_of_match[] = {
+ { .compatible = "google,goldfish-rtc", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match);
+
+static struct platform_driver goldfish_rtc = {
+ .probe = goldfish_rtc_probe,
+ .driver = {
+ .name = "goldfish_rtc",
+ .of_match_table = goldfish_rtc_of_match,
+ }
+};
+
+module_platform_driver(goldfish_rtc);
--
2.7.4
