| /* drivers/rtc/rtc-goldfish.c |
| ** |
| ** Copyright (C) 2007 Google, Inc. |
| ** |
| ** 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 <asm/io.h> |
| #include <linux/acpi.h> |
| #include <linux/export.h> |
| #include <linux/interrupt.h> |
| #include <linux/irq.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/rtc.h> |
| #include <linux/slab.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) |
| { |
| int64_t time; |
| struct goldfish_rtc *qrtc = platform_get_drvdata(to_platform_device(dev)); |
| void __iomem *base = qrtc->base; |
| |
| time = readl(base + TIMER_TIME_LOW); |
| time |= (int64_t)readl(base + TIMER_TIME_HIGH) << 32; |
| do_div(time, NSEC_PER_SEC); |
| |
| rtc_time_to_tm(time, tm); |
| return 0; |
| } |
| |
| static struct rtc_class_ops goldfish_rtc_ops = { |
| // .ioctl = goldfish_rtc_ioctl, |
| .read_time = goldfish_rtc_read_time, |
| // .set_time = goldfish_rtc_set_time, |
| // .read_alarm = goldfish_rtc_read_alarm, |
| // .set_alarm = goldfish_rtc_set_alarm, |
| }; |
| |
| |
| 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 = kzalloc(sizeof(*qrtc), GFP_KERNEL); |
| if(qrtc == NULL) { |
| ret = -ENOMEM; |
| goto err_qrtc_alloc_failed; |
| } |
| platform_set_drvdata(pdev, qrtc); |
| |
| r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if(r == NULL) { |
| ret = -ENODEV; |
| goto err_no_io_base; |
| } |
| |
| rtc_dev_addr = r->start; |
| rtc_dev_len = resource_size(r); |
| qrtc->base = ioremap(rtc_dev_addr, rtc_dev_len); |
| qrtc->irq = platform_get_irq(pdev, 0); |
| if(qrtc->irq < 0) { |
| ret = -ENODEV; |
| goto err_no_irq; |
| } |
| qrtc->rtc = rtc_device_register(pdev->name, &pdev->dev, |
| &goldfish_rtc_ops, THIS_MODULE); |
| if (IS_ERR(qrtc->rtc)) { |
| ret = PTR_ERR(qrtc->rtc); |
| goto err_rtc_device_register_failed; |
| } |
| |
| ret = request_irq(qrtc->irq, goldfish_rtc_interrupt, 0, pdev->name, qrtc); |
| if(ret) |
| goto request_irq; |
| |
| return 0; |
| |
| free_irq(qrtc->irq, qrtc); |
| request_irq: |
| rtc_device_unregister(qrtc->rtc); |
| err_rtc_device_register_failed: |
| err_no_irq: |
| err_no_io_base: |
| kfree(qrtc); |
| err_qrtc_alloc_failed: |
| return ret; |
| } |
| |
| static int goldfish_rtc_remove(struct platform_device *pdev) |
| { |
| struct goldfish_rtc *qrtc = platform_get_drvdata(pdev); |
| free_irq(qrtc->irq, qrtc); |
| rtc_device_unregister(qrtc->rtc); |
| kfree(qrtc); |
| return 0; |
| } |
| |
| static const struct of_device_id goldfish_rtc_of_match[] = { |
| { .compatible = "generic,goldfish-rtc", }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, goldfish_rtc_of_match); |
| |
| static const struct acpi_device_id goldfish_rtc_acpi_match[] = { |
| { "GFSH0007", 0 }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(acpi, golfish_rtc_acpi_match); |
| |
| static struct platform_driver goldfish_rtc = { |
| .probe = goldfish_rtc_probe, |
| .remove = goldfish_rtc_remove, |
| .driver = { |
| .name = "goldfish_rtc", |
| .of_match_table = goldfish_rtc_of_match, |
| .acpi_match_table = ACPI_PTR(goldfish_rtc_acpi_match), |
| } |
| }; |
| |
| module_platform_driver(goldfish_rtc); |
| |