| /* |
| * Freescale STMP37XX/STMP378X Real Time Clock driver |
| * |
| * Copyright (c) 2007 Sigmatel, Inc. |
| * Peter Hartley, <peter.hartley@sigmatel.com> |
| * |
| * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. |
| * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. |
| * Copyright 2011 Wolfram Sang, Pengutronix e.K. |
| */ |
| |
| /* |
| * The code contained herein is licensed under the GNU General Public |
| * License. You may obtain a copy of the GNU General Public License |
| * Version 2 or later at the following locations: |
| * |
| * http://www.opensource.org/licenses/gpl-license.html |
| * http://www.gnu.org/copyleft/gpl.html |
| */ |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/io.h> |
| #include <linux/init.h> |
| #include <linux/platform_device.h> |
| #include <linux/interrupt.h> |
| #include <linux/rtc.h> |
| #include <linux/slab.h> |
| #include <linux/of_device.h> |
| #include <linux/of.h> |
| #include <linux/stmp_device.h> |
| #include <linux/stmp3xxx_rtc_wdt.h> |
| |
| #include <mach/common.h> |
| |
| #define STMP3XXX_RTC_CTRL 0x0 |
| #define STMP3XXX_RTC_CTRL_SET 0x4 |
| #define STMP3XXX_RTC_CTRL_CLR 0x8 |
| #define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001 |
| #define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002 |
| #define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004 |
| #define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010 |
| |
| #define STMP3XXX_RTC_STAT 0x10 |
| #define STMP3XXX_RTC_STAT_STALE_SHIFT 16 |
| #define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000 |
| |
| #define STMP3XXX_RTC_SECONDS 0x30 |
| |
| #define STMP3XXX_RTC_ALARM 0x40 |
| |
| #define STMP3XXX_RTC_WATCHDOG 0x50 |
| |
| #define STMP3XXX_RTC_PERSISTENT0 0x60 |
| #define STMP3XXX_RTC_PERSISTENT0_SET 0x64 |
| #define STMP3XXX_RTC_PERSISTENT0_CLR 0x68 |
| #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002 |
| #define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004 |
| #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080 |
| |
| #define STMP3XXX_RTC_PERSISTENT1 0x70 |
| /* missing bitmask in headers */ |
| #define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000 |
| |
| struct stmp3xxx_rtc_data { |
| struct rtc_device *rtc; |
| void __iomem *io; |
| int irq_alarm; |
| }; |
| |
| #if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG) |
| /** |
| * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC |
| * @dev: the parent device of the watchdog (= the RTC) |
| * @timeout: the desired value for the timeout register of the watchdog. |
| * 0 disables the watchdog |
| * |
| * The watchdog needs one register and two bits which are in the RTC domain. |
| * To handle the resource conflict, the RTC driver will create another |
| * platform_device for the watchdog driver as a child of the RTC device. |
| * The watchdog driver is passed the below accessor function via platform_data |
| * to configure the watchdog. Locking is not needed because accessing SET/CLR |
| * registers is atomic. |
| */ |
| |
| static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| if (timeout) { |
| writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG); |
| writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, |
| rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET); |
| writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET); |
| } else { |
| writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, |
| rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR); |
| writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR); |
| } |
| } |
| |
| static struct stmp3xxx_wdt_pdata wdt_pdata = { |
| .wdt_set_timeout = stmp3xxx_wdt_set_timeout, |
| }; |
| |
| static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) |
| { |
| struct platform_device *wdt_pdev = |
| platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id); |
| |
| if (wdt_pdev) { |
| wdt_pdev->dev.parent = &rtc_pdev->dev; |
| wdt_pdev->dev.platform_data = &wdt_pdata; |
| platform_device_add(wdt_pdev); |
| } |
| } |
| #else |
| static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) |
| { |
| } |
| #endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */ |
| |
| static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data) |
| { |
| /* |
| * The datasheet doesn't say which way round the |
| * NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0, |
| * 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS |
| */ |
| while (readl(rtc_data->io + STMP3XXX_RTC_STAT) & |
| (0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT)) |
| cpu_relax(); |
| } |
| |
| /* Time read/write */ |
| static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| stmp3xxx_wait_time(rtc_data); |
| rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm); |
| return 0; |
| } |
| |
| static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS); |
| stmp3xxx_wait_time(rtc_data); |
| return 0; |
| } |
| |
| /* interrupt(s) handler */ |
| static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id); |
| u32 status = readl(rtc_data->io + STMP3XXX_RTC_CTRL); |
| |
| if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) { |
| writel(STMP3XXX_RTC_CTRL_ALARM_IRQ, |
| rtc_data->io + STMP3XXX_RTC_CTRL_CLR); |
| rtc_update_irq(rtc_data->rtc, 1, RTC_AF | RTC_IRQF); |
| return IRQ_HANDLED; |
| } |
| |
| return IRQ_NONE; |
| } |
| |
| static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| if (enabled) { |
| writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET); |
| writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, |
| rtc_data->io + STMP3XXX_RTC_CTRL_SET); |
| } else { |
| writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); |
| writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, |
| rtc_data->io + STMP3XXX_RTC_CTRL_CLR); |
| } |
| return 0; |
| } |
| |
| static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time); |
| return 0; |
| } |
| |
| static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| { |
| unsigned long t; |
| struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); |
| |
| rtc_tm_to_time(&alm->time, &t); |
| writel(t, rtc_data->io + STMP3XXX_RTC_ALARM); |
| |
| stmp3xxx_alarm_irq_enable(dev, alm->enabled); |
| |
| return 0; |
| } |
| |
| static struct rtc_class_ops stmp3xxx_rtc_ops = { |
| .alarm_irq_enable = |
| stmp3xxx_alarm_irq_enable, |
| .read_time = stmp3xxx_rtc_gettime, |
| .set_mmss = stmp3xxx_rtc_set_mmss, |
| .read_alarm = stmp3xxx_rtc_read_alarm, |
| .set_alarm = stmp3xxx_rtc_set_alarm, |
| }; |
| |
| static int stmp3xxx_rtc_remove(struct platform_device *pdev) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev); |
| |
| if (!rtc_data) |
| return 0; |
| |
| writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, |
| rtc_data->io + STMP3XXX_RTC_CTRL_CLR); |
| platform_set_drvdata(pdev, NULL); |
| |
| return 0; |
| } |
| |
| static int stmp3xxx_rtc_probe(struct platform_device *pdev) |
| { |
| struct stmp3xxx_rtc_data *rtc_data; |
| struct resource *r; |
| int err; |
| |
| rtc_data = devm_kzalloc(&pdev->dev, sizeof(*rtc_data), GFP_KERNEL); |
| if (!rtc_data) |
| return -ENOMEM; |
| |
| r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!r) { |
| dev_err(&pdev->dev, "failed to get resource\n"); |
| return -ENXIO; |
| } |
| |
| rtc_data->io = devm_ioremap(&pdev->dev, r->start, resource_size(r)); |
| if (!rtc_data->io) { |
| dev_err(&pdev->dev, "ioremap failed\n"); |
| return -EIO; |
| } |
| |
| rtc_data->irq_alarm = platform_get_irq(pdev, 0); |
| |
| if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) & |
| STMP3XXX_RTC_STAT_RTC_PRESENT)) { |
| dev_err(&pdev->dev, "no device onboard\n"); |
| return -ENODEV; |
| } |
| |
| platform_set_drvdata(pdev, rtc_data); |
| |
| mxs_reset_block(rtc_data->io); |
| writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); |
| |
| writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN | |
| STMP3XXX_RTC_CTRL_ALARM_IRQ_EN, |
| rtc_data->io + STMP3XXX_RTC_CTRL_CLR); |
| |
| rtc_data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, |
| &stmp3xxx_rtc_ops, THIS_MODULE); |
| if (IS_ERR(rtc_data->rtc)) { |
| err = PTR_ERR(rtc_data->rtc); |
| goto out; |
| } |
| |
| err = devm_request_irq(&pdev->dev, rtc_data->irq_alarm, |
| stmp3xxx_rtc_interrupt, 0, "RTC alarm", &pdev->dev); |
| if (err) { |
| dev_err(&pdev->dev, "Cannot claim IRQ%d\n", |
| rtc_data->irq_alarm); |
| goto out; |
| } |
| |
| stmp3xxx_wdt_register(pdev); |
| return 0; |
| |
| out: |
| platform_set_drvdata(pdev, NULL); |
| return err; |
| } |
| |
| #ifdef CONFIG_PM |
| static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state) |
| { |
| return 0; |
| } |
| |
| static int stmp3xxx_rtc_resume(struct platform_device *dev) |
| { |
| struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev); |
| |
| mxs_reset_block(rtc_data->io); |
| writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN | |
| STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE, |
| rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR); |
| return 0; |
| } |
| #else |
| #define stmp3xxx_rtc_suspend NULL |
| #define stmp3xxx_rtc_resume NULL |
| #endif |
| |
| static const struct of_device_id rtc_dt_ids[] = { |
| { .compatible = "fsl,stmp3xxx-rtc", }, |
| { /* sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, rtc_dt_ids); |
| |
| static struct platform_driver stmp3xxx_rtcdrv = { |
| .probe = stmp3xxx_rtc_probe, |
| .remove = stmp3xxx_rtc_remove, |
| .suspend = stmp3xxx_rtc_suspend, |
| .resume = stmp3xxx_rtc_resume, |
| .driver = { |
| .name = "stmp3xxx-rtc", |
| .owner = THIS_MODULE, |
| .of_match_table = of_match_ptr(rtc_dt_ids), |
| }, |
| }; |
| |
| module_platform_driver(stmp3xxx_rtcdrv); |
| |
| MODULE_DESCRIPTION("STMP3xxx RTC Driver"); |
| MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com> and " |
| "Wolfram Sang <w.sang@pengutronix.de>"); |
| MODULE_LICENSE("GPL"); |