diff options
Diffstat (limited to 'drivers/rtc/rtc-mxc.c')
| -rw-r--r-- | drivers/rtc/rtc-mxc.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c new file mode 100644 index 000000000..a8cfbde04 --- /dev/null +++ b/drivers/rtc/rtc-mxc.c @@ -0,0 +1,450 @@ +// 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/pm_wakeirq.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; + unsigned long flags; + + spin_lock_irqsave(&pdata->rtc->irq_lock, flags); + reg = readw(ioaddr + RTC_RTCIENR); + + if (enabled) + reg |= bit; + else + reg &= ~bit; + + writew(reg, ioaddr + RTC_RTCIENR); + spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags); +} + +/* 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_time(struct device *dev, struct rtc_time *tm) +{ + time64_t 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_time = mxc_rtc_set_time, + .read_alarm = mxc_rtc_read_alarm, + .set_alarm = mxc_rtc_set_alarm, + .alarm_irq_enable = mxc_rtc_alarm_irq_enable, +}; + +static void mxc_rtc_action(void *p) +{ + struct rtc_plat_data *pdata = p; + + clk_disable_unprepare(pdata->clk_ref); + clk_disable_unprepare(pdata->clk_ipg); +} + +static int mxc_rtc_probe(struct platform_device *pdev) +{ + 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; + + pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pdata->ioaddr)) + return PTR_ERR(pdata->ioaddr); + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + pdata->rtc = rtc; + rtc->ops = &mxc_rtc_ops; + if (is_imx1_rtc(pdata)) { + struct rtc_time tm; + + /* 9bit days + hours minutes seconds */ + rtc->range_max = (1 << 9) * 86400 - 1; + + /* + * Set the start date as beginning of the current year. This can + * be overridden using device tree. + */ + rtc_time64_to_tm(ktime_get_real_seconds(), &tm); + rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0); + rtc->set_start_time = true; + } else { + /* 16bit days + hours minutes seconds */ + rtc->range_max = (1 << 16) * 86400ULL - 1; + } + + 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)) { + clk_disable_unprepare(pdata->clk_ipg); + dev_err(&pdev->dev, "unable to get ref clock!\n"); + return PTR_ERR(pdata->clk_ref); + } + + ret = clk_prepare_enable(pdata->clk_ref); + if (ret) { + clk_disable_unprepare(pdata->clk_ipg); + return ret; + } + + ret = devm_add_action_or_reset(&pdev->dev, mxc_rtc_action, pdata); + if (ret) + return ret; + + 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); + return -EINVAL; + } + + 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"); + return -EIO; + } + + 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); + ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq); + if (ret) + dev_err(&pdev->dev, "failed to enable irq wake\n"); + } + + ret = rtc_register_device(rtc); + + return ret; +} + +static struct platform_driver mxc_rtc_driver = { + .driver = { + .name = "mxc_rtc", + .of_match_table = of_match_ptr(imx_rtc_dt_ids), + }, + .id_table = imx_rtc_devtype, + .probe = mxc_rtc_probe, +}; + +module_platform_driver(mxc_rtc_driver) + +MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); +MODULE_DESCRIPTION("RTC driver for Freescale MXC"); +MODULE_LICENSE("GPL"); + |