// SPDX-License-Identifier: GPL-2.0+ // // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved. #include <linux/io.h> #include <linux/rtc.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/clk.h> #include <linux/of.h> #include <linux/of_device.h> #define RTC_INPUT_CLK_32768HZ (0x00 << 5) #define RTC_INPUT_CLK_32000HZ (0x01 << 5) #define RTC_INPUT_CLK_38400HZ (0x02 << 5) #define RTC_SW_BIT (1 << 0) #define RTC_ALM_BIT (1 << 2) #define RTC_1HZ_BIT (1 << 4) #define RTC_2HZ_BIT (1 << 7) #define RTC_SAM0_BIT (1 << 8) #define RTC_SAM1_BIT (1 << 9) #define RTC_SAM2_BIT (1 << 10) #define RTC_SAM3_BIT (1 << 11) #define RTC_SAM4_BIT (1 << 12) #define RTC_SAM5_BIT (1 << 13) #define RTC_SAM6_BIT (1 << 14) #define RTC_SAM7_BIT (1 << 15) #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \ RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \ RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT) #define RTC_ENABLE_BIT (1 << 7) #define MAX_PIE_NUM 9 #define MAX_PIE_FREQ 512 #define MXC_RTC_TIME 0 #define MXC_RTC_ALARM 1 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */ #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */ #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */ #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */ #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */ #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */ #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */ #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */ #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */ #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */ #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */ #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */ #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */ enum imx_rtc_type { IMX1_RTC, IMX21_RTC, }; struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; int irq; struct clk *clk_ref; struct clk *clk_ipg; struct rtc_time g_rtc_alarm; enum imx_rtc_type devtype; }; static const struct platform_device_id imx_rtc_devtype[] = { { .name = "imx1-rtc", .driver_data = IMX1_RTC, }, { .name = "imx21-rtc", .driver_data = IMX21_RTC, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(platform, imx_rtc_devtype); #ifdef CONFIG_OF static const struct of_device_id imx_rtc_dt_ids[] = { { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC }, { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC }, {} }; MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids); #endif static inline int is_imx1_rtc(struct rtc_plat_data *data) { return data->devtype == IMX1_RTC; } /* * This function is used to obtain the RTC time or the alarm value in * second. */ static time64_t get_alarm_or_time(struct device *dev, int time_alarm) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr; u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0; switch (time_alarm) { case MXC_RTC_TIME: day = readw(ioaddr + RTC_DAYR); hr_min = readw(ioaddr + RTC_HOURMIN); sec = readw(ioaddr + RTC_SECOND); break; case MXC_RTC_ALARM: day = readw(ioaddr + RTC_DAYALARM); hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff; sec = readw(ioaddr + RTC_ALRM_SEC); break; } hr = hr_min >> 8; min = hr_min & 0xff; return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec; } /* * This function sets the RTC alarm value or the time value. */ static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time) { u32 tod, day, hr, min, sec, temp; struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr; day = div_s64_rem(time, 86400, &tod); /* time is within a day now */ hr = tod / 3600; tod -= hr * 3600; /* time is within an hour now */ min = tod / 60; sec = tod - min * 60; temp = (hr << 8) + min; switch (time_alarm) { case MXC_RTC_TIME: writew(day, ioaddr + RTC_DAYR); writew(sec, ioaddr + RTC_SECOND); writew(temp, ioaddr + RTC_HOURMIN); break; case MXC_RTC_ALARM: writew(day, ioaddr + RTC_DAYALARM); writew(sec, ioaddr + RTC_ALRM_SEC); writew(temp, ioaddr + RTC_ALRM_HM); break; } } /* * This function updates the RTC alarm registers and then clears all the * interrupt status bits. */ static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm) { time64_t time; struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr; time = rtc_tm_to_time64(alrm); /* clear all the interrupt status bits */ writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR); set_alarm_or_time(dev, MXC_RTC_ALARM, time); } static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit, unsigned int enabled) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr; u32 reg; spin_lock_irq(&pdata->rtc->irq_lock); reg = readw(ioaddr + RTC_RTCIENR); if (enabled) reg |= bit; else reg &= ~bit; writew(reg, ioaddr + RTC_RTCIENR); spin_unlock_irq(&pdata->rtc->irq_lock); } /* This function is the RTC interrupt service routine. */ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id) { struct platform_device *pdev = dev_id; struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; unsigned long flags; u32 status; u32 events = 0; spin_lock_irqsave(&pdata->rtc->irq_lock, flags); status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR); /* clear interrupt sources */ writew(status, ioaddr + RTC_RTCISR); /* update irq data & counter */ if (status & RTC_ALM_BIT) { events |= (RTC_AF | RTC_IRQF); /* RTC alarm should be one-shot */ mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0); } if (status & PIT_ALL_ON) events |= (RTC_PF | RTC_IRQF); rtc_update_irq(pdata->rtc, 1, events); spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); return IRQ_HANDLED; } static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled); return 0; } /* * This function reads the current RTC time into tm in Gregorian date. */ static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm) { time64_t val; /* Avoid roll-over from reading the different registers */ do { val = get_alarm_or_time(dev, MXC_RTC_TIME); } while (val != get_alarm_or_time(dev, MXC_RTC_TIME)); rtc_time64_to_tm(val, tm); return 0; } /* * This function sets the internal RTC time based on tm in Gregorian date. */ static int mxc_rtc_set_mmss(struct device *dev, time64_t time) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); /* * TTC_DAYR register is 9-bit in MX1 SoC, save time and day of year only */ if (is_imx1_rtc(pdata)) { struct rtc_time tm; rtc_time64_to_tm(time, &tm); tm.tm_year = 70; time = rtc_tm_to_time64(&tm); } /* Avoid roll-over from reading the different registers */ do { set_alarm_or_time(dev, MXC_RTC_TIME, time); } while (time != get_alarm_or_time(dev, MXC_RTC_TIME)); return 0; } /* * This function reads the current alarm value into the passed in 'alrm' * argument. It updates the alrm's pending field value based on the whether * an alarm interrupt occurs or not. */ static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); void __iomem *ioaddr = pdata->ioaddr; rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time); alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0; return 0; } /* * This function sets the RTC alarm based on passed in alrm. */ static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); rtc_update_alarm(dev, &alrm->time); memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time)); mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled); return 0; } /* RTC layer */ static const struct rtc_class_ops mxc_rtc_ops = { .read_time = mxc_rtc_read_time, .set_mmss64 = mxc_rtc_set_mmss, .read_alarm = mxc_rtc_read_alarm, .set_alarm = mxc_rtc_set_alarm, .alarm_irq_enable = mxc_rtc_alarm_irq_enable, }; static int mxc_rtc_probe(struct platform_device *pdev) { struct resource *res; struct rtc_device *rtc; struct rtc_plat_data *pdata = NULL; u32 reg; unsigned long rate; int ret; const struct of_device_id *of_id; pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; of_id = of_match_device(imx_rtc_dt_ids, &pdev->dev); if (of_id) pdata->devtype = (enum imx_rtc_type)of_id->data; else pdata->devtype = pdev->id_entry->driver_data; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pdata->ioaddr = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(pdata->ioaddr)) return PTR_ERR(pdata->ioaddr); pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(pdata->clk_ipg)) { dev_err(&pdev->dev, "unable to get ipg clock!\n"); return PTR_ERR(pdata->clk_ipg); } ret = clk_prepare_enable(pdata->clk_ipg); if (ret) return ret; pdata->clk_ref = devm_clk_get(&pdev->dev, "ref"); if (IS_ERR(pdata->clk_ref)) { dev_err(&pdev->dev, "unable to get ref clock!\n"); ret = PTR_ERR(pdata->clk_ref); goto exit_put_clk_ipg; } ret = clk_prepare_enable(pdata->clk_ref); if (ret) goto exit_put_clk_ipg; rate = clk_get_rate(pdata->clk_ref); if (rate == 32768) reg = RTC_INPUT_CLK_32768HZ; else if (rate == 32000) reg = RTC_INPUT_CLK_32000HZ; else if (rate == 38400) reg = RTC_INPUT_CLK_38400HZ; else { dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate); ret = -EINVAL; goto exit_put_clk_ref; } reg |= RTC_ENABLE_BIT; writew(reg, (pdata->ioaddr + RTC_RTCCTL)); if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) { dev_err(&pdev->dev, "hardware module can't be enabled!\n"); ret = -EIO; goto exit_put_clk_ref; } platform_set_drvdata(pdev, pdata); /* Configure and enable the RTC */ pdata->irq = platform_get_irq(pdev, 0); if (pdata->irq >= 0 && devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt, IRQF_SHARED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); pdata->irq = -1; } if (pdata->irq >= 0) device_init_wakeup(&pdev->dev, 1); rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &mxc_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { ret = PTR_ERR(rtc); goto exit_put_clk_ref; } pdata->rtc = rtc; return 0; exit_put_clk_ref: clk_disable_unprepare(pdata->clk_ref); exit_put_clk_ipg: clk_disable_unprepare(pdata->clk_ipg); return ret; } static int mxc_rtc_remove(struct platform_device *pdev) { struct rtc_plat_data *pdata = platform_get_drvdata(pdev); clk_disable_unprepare(pdata->clk_ref); clk_disable_unprepare(pdata->clk_ipg); return 0; } #ifdef CONFIG_PM_SLEEP static int mxc_rtc_suspend(struct device *dev) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); if (device_may_wakeup(dev)) enable_irq_wake(pdata->irq); return 0; } static int mxc_rtc_resume(struct device *dev) { struct rtc_plat_data *pdata = dev_get_drvdata(dev); if (device_may_wakeup(dev)) disable_irq_wake(pdata->irq); return 0; } #endif static SIMPLE_DEV_PM_OPS(mxc_rtc_pm_ops, mxc_rtc_suspend, mxc_rtc_resume); static struct platform_driver mxc_rtc_driver = { .driver = { .name = "mxc_rtc", .of_match_table = of_match_ptr(imx_rtc_dt_ids), .pm = &mxc_rtc_pm_ops, }, .id_table = imx_rtc_devtype, .probe = mxc_rtc_probe, .remove = mxc_rtc_remove, }; module_platform_driver(mxc_rtc_driver) MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); MODULE_DESCRIPTION("RTC driver for Freescale MXC"); MODULE_LICENSE("GPL");