Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752488AbdF1QBj (ORCPT ); Wed, 28 Jun 2017 12:01:39 -0400 Received: from mx2.rt-rk.com ([89.216.37.149]:50845 "EHLO mail.rt-rk.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751526AbdF1P7E (ORCPT ); Wed, 28 Jun 2017 11:59:04 -0400 From: Aleksandar Markovic To: linux-mips@linux-mips.org Cc: Aleksandar Markovic , Miodrag Dinic , Goran Ferenc , Alessandro Zummo , Alexandre Belloni , "David S. Miller" , Douglas Leung , Greg Kroah-Hartman , James Hogan , linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, "Martin K. Petersen" , Mauro Carvalho Chehab , Paul Burton , Petar Jovanovic , Raghu Gandham Subject: [PATCH v2 02/10] MIPS: ranchu: Add Goldfish RTC driver Date: Wed, 28 Jun 2017 17:46:55 +0200 Message-Id: <1498664922-28493-3-git-send-email-aleksandar.markovic@rt-rk.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498664922-28493-1-git-send-email-aleksandar.markovic@rt-rk.com> References: <1498664922-28493-1-git-send-email-aleksandar.markovic@rt-rk.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5799 Lines: 200 From: Aleksandar Markovic Add device driver for a virtual Goldfish RTC clock. The driver can be built only if CONFIG_MIPS and CONFIG_GOLDFISH are set. The compatible string used by OS for binding the driver is defined as "google,goldfish-rtc". Signed-off-by: Miodrag Dinic Signed-off-by: Goran Ferenc Signed-off-by: Aleksandar Markovic --- MAINTAINERS | 1 + drivers/rtc/Kconfig | 6 ++ drivers/rtc/Makefile | 1 + drivers/rtc/rtc-goldfish.c | 136 +++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 144 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 S: Supported F: Documentation/devicetree/bindings/rtc/google,goldfish-rtc.txt +F: drivers/rtc/rtc-goldfish.c ANDROID ION DRIVER M: Laura Abbott 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..e206a98 --- /dev/null +++ b/drivers/rtc/rtc-goldfish.c @@ -0,0 +1,136 @@ +/* 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 +#include +#include + +#define TIMER_TIME_LOW 0x00 /* get low bits of current time */ + /* and update TIMER_TIME_HIGH */ +#define TIMER_TIME_HIGH 0x04 /* get high bits of time at last */ + /* TIMER_TIME_LOW read */ +#define TIMER_ALARM_LOW 0x08 /* set low bits of alarm and */ + /* activate it */ +#define TIMER_ALARM_HIGH 0x0c /* set high bits of next alarm */ +#define TIMER_CLEAR_INTERRUPT 0x10 +#define TIMER_CLEAR_ALARM 0x14 + +struct goldfish_rtc { + void __iomem *base; + u32 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) +{ + u64 time; + u64 time_low; + u64 time_high; + u64 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 = (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) +{ + struct resource *r; + struct goldfish_rtc *qrtc; + unsigned long rtc_dev_len; + unsigned long rtc_dev_addr; + int err; + + qrtc = devm_kzalloc(&pdev->dev, sizeof(*qrtc), GFP_KERNEL); + if (qrtc == NULL) + return -ENOMEM; + + platform_set_drvdata(pdev, qrtc); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) + return -ENODEV; + + 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)) + return -ENODEV; + + qrtc->irq = platform_get_irq(pdev, 0); + if (qrtc->irq < 0) + return -ENODEV; + + qrtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &goldfish_rtc_ops, THIS_MODULE); + if (IS_ERR(qrtc->rtc)) + return PTR_ERR(qrtc->rtc); + + err = devm_request_irq(&pdev->dev, qrtc->irq, goldfish_rtc_interrupt, + 0, pdev->name, qrtc); + if (err) + return err; + + return 0; +} + +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