/* * Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved. * * 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/io.h> #include <linux/rtc.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/clk.h> #include <mach/hardware.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 static const u32 PIE_BIT_DEF[MAX_PIE_NUM][2] = { { 2, RTC_2HZ_BIT }, { 4, RTC_SAM0_BIT }, { 8, RTC_SAM1_BIT }, { 16, RTC_SAM2_BIT }, { 32, RTC_SAM3_BIT }, { 64, RTC_SAM4_BIT }, { 128, RTC_SAM5_BIT }, { 256, RTC_SAM6_BIT }, { MAX_PIE_FREQ, RTC_SAM7_BIT }, }; /* Those are the bits from a classic RTC we want to mimic */ #define RTC_IRQF 0x80 /* any of the following 3 is active */ #define RTC_PF 0x40 /* Periodic interrupt */ #define RTC_AF 0x20 /* Alarm interrupt */ #define RTC_UF 0x10 /* Update interrupt for 1Hz RTC */ #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 */ struct rtc_plat_data { struct rtc_device *rtc; void __iomem *ioaddr; int irq; struct clk *clk; unsigned int irqen; int alrm_sec; int alrm_min; int alrm_hour; int alrm_mday; struct timespec mxc_rtc_delta; struct rtc_time g_rtc_alarm; }; /* * This function is used to obtain the RTC time or the alarm value in * second. */ static u32 get_alarm_or_time(struct device *dev, int time_alarm) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 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 (((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, u32 time) { u32 day, hr, min, sec, temp; struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; day = time / 86400; time -= day * 86400; /* time is within a day now */ hr = time / 3600; time -= hr * 3600; /* time is within an hour now */ min = time / 60; sec = time - 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 int rtc_update_alarm(struct device *dev, struct rtc_time *alrm) { struct rtc_time alarm_tm, now_tm; unsigned long now, time; int ret; struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; now = get_alarm_or_time(dev, MXC_RTC_TIME); rtc_time_to_tm(now, &now_tm); alarm_tm.tm_year = now_tm.tm_year; alarm_tm.tm_mon = now_tm.tm_mon; alarm_tm.tm_mday = now_tm.tm_mday; alarm_tm.tm_hour = alrm->tm_hour; alarm_tm.tm_min = alrm->tm_min; alarm_tm.tm_sec = alrm->tm_sec; rtc_tm_to_time(&now_tm, &now); rtc_tm_to_time(&alarm_tm, &time); if (time < now) { time += 60 * 60 * 24; rtc_time_to_tm(time, &alarm_tm); } ret = rtc_tm_to_time(&alarm_tm, &time); /* clear all the interrupt status bits */ writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR); set_alarm_or_time(dev, MXC_RTC_ALARM, time); return ret; } /* 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; u32 status; u32 events = 0; spin_lock_irq(&pdata->rtc->irq_lock); status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR); /* clear interrupt sources */ writew(status, ioaddr + RTC_RTCISR); /* clear alarm interrupt if it has occurred */ if (status & RTC_ALM_BIT) status &= ~RTC_ALM_BIT; /* update irq data & counter */ if (status & RTC_ALM_BIT) events |= (RTC_AF | RTC_IRQF); if (status & RTC_1HZ_BIT) events |= (RTC_UF | RTC_IRQF); if (status & PIT_ALL_ON) events |= (RTC_PF | RTC_IRQF); if ((status & RTC_ALM_BIT) && rtc_valid_tm(&pdata->g_rtc_alarm)) rtc_update_alarm(&pdev->dev, &pdata->g_rtc_alarm); rtc_update_irq(pdata->rtc, 1, events); spin_unlock_irq(&pdata->rtc->irq_lock); return IRQ_HANDLED; } /* * Clear all interrupts and release the IRQ */ static void mxc_rtc_release(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; spin_lock_irq(&pdata->rtc->irq_lock); /* Disable all rtc interrupts */ writew(0, ioaddr + RTC_RTCIENR); /* Clear all interrupt status */ writew(0xffffffff, ioaddr + RTC_RTCISR); spin_unlock_irq(&pdata->rtc->irq_lock); } static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit, unsigned int enabled) { struct platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); 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); } static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled); return 0; } static int mxc_rtc_update_irq_enable(struct device *dev, unsigned int enabled) { mxc_rtc_irq_enable(dev, RTC_1HZ_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) { u32 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_time_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, unsigned long time) { /* 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 platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); void __iomem *ioaddr = pdata->ioaddr; rtc_time_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 platform_device *pdev = to_platform_device(dev); struct rtc_plat_data *pdata = platform_get_drvdata(pdev); int ret; if (rtc_valid_tm(&alrm->time)) { if (alrm->time.tm_sec > 59 || alrm->time.tm_hour > 23 || alrm->time.tm_min > 59) return -EINVAL; ret = rtc_update_alarm(dev, &alrm->time); } else { ret = rtc_valid_tm(&alrm->time); if (ret) return ret; ret = rtc_update_alarm(dev, &alrm->time); } if (ret) return ret; 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 struct rtc_class_ops mxc_rtc_ops = { .release = mxc_rtc_release, .read_time = mxc_rtc_read_time, .set_mmss = mxc_rtc_set_mmss, .read_alarm = mxc_rtc_read_alarm, .set_alarm = mxc_rtc_set_alarm, .alarm_irq_enable = mxc_rtc_alarm_irq_enable, .update_irq_enable = mxc_rtc_update_irq_enable, }; static int __init mxc_rtc_probe(struct platform_device *pdev) { struct clk *clk; struct resource *res; struct rtc_device *rtc; struct rtc_plat_data *pdata = NULL; u32 reg; int ret, rate; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); if (!pdata) return -ENOMEM; pdata->ioaddr = ioremap(res->start, resource_size(res)); clk = clk_get(&pdev->dev, "ckil"); if (IS_ERR(clk)) { iounmap(pdata->ioaddr); ret = PTR_ERR(clk); goto exit_free_pdata; } rate = clk_get_rate(clk); clk_put(clk); 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", clk_get_rate(clk)); ret = -EINVAL; goto exit_free_pdata; } 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_free_pdata; } pdata->clk = clk_get(&pdev->dev, "rtc"); if (IS_ERR(pdata->clk)) { dev_err(&pdev->dev, "unable to get clock!\n"); ret = PTR_ERR(pdata->clk); goto exit_free_pdata; } clk_enable(pdata->clk); rtc = rtc_device_register(pdev->name, &pdev->dev, &mxc_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) { ret = PTR_ERR(rtc); goto exit_put_clk; } pdata->rtc = rtc; platform_set_drvdata(pdev, pdata); /* Configure and enable the RTC */ pdata->irq = platform_get_irq(pdev, 0); if (pdata->irq >= 0 && request_irq(pdata->irq, mxc_rtc_interrupt, IRQF_SHARED, pdev->name, pdev) < 0) { dev_warn(&pdev->dev, "interrupt not available.\n"); pdata->irq = -1; } return 0; exit_put_clk: clk_put(pdata->clk); exit_free_pdata: kfree(pdata); return ret; } static int __exit mxc_rtc_remove(struct platform_device *pdev) { struct rtc_plat_data *pdata = platform_get_drvdata(pdev); rtc_device_unregister(pdata->rtc); if (pdata->irq >= 0) free_irq(pdata->irq, pdev); clk_disable(pdata->clk); clk_put(pdata->clk); kfree(pdata); platform_set_drvdata(pdev, NULL); return 0; } static struct platform_driver mxc_rtc_driver = { .driver = { .name = "mxc_rtc", .owner = THIS_MODULE, }, .remove = __exit_p(mxc_rtc_remove), }; static int __init mxc_rtc_init(void) { return platform_driver_probe(&mxc_rtc_driver, mxc_rtc_probe); } static void __exit mxc_rtc_exit(void) { platform_driver_unregister(&mxc_rtc_driver); } module_init(mxc_rtc_init); module_exit(mxc_rtc_exit); MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); MODULE_DESCRIPTION("RTC driver for Freescale MXC"); MODULE_LICENSE("GPL");