diff options
Diffstat (limited to 'drivers/rtc/rtc-mxc.c')
| -rw-r--r-- | drivers/rtc/rtc-mxc.c | 507 |
1 files changed, 507 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c new file mode 100644 index 000000000000..6bd5072d4eb7 --- /dev/null +++ b/drivers/rtc/rtc-mxc.c @@ -0,0 +1,507 @@ +/* + * 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)) + return PTR_ERR(clk); + + 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"); + |