1 // SPDX-License-Identifier: GPL-2.0+
3 // Copyright 2004-2008 Freescale Semiconductor, Inc. All Rights Reserved.
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/interrupt.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_wakeirq.h>
12 #include <linux/clk.h>
14 #include <linux/of_device.h>
16 #define RTC_INPUT_CLK_32768HZ (0x00 << 5)
17 #define RTC_INPUT_CLK_32000HZ (0x01 << 5)
18 #define RTC_INPUT_CLK_38400HZ (0x02 << 5)
20 #define RTC_SW_BIT (1 << 0)
21 #define RTC_ALM_BIT (1 << 2)
22 #define RTC_1HZ_BIT (1 << 4)
23 #define RTC_2HZ_BIT (1 << 7)
24 #define RTC_SAM0_BIT (1 << 8)
25 #define RTC_SAM1_BIT (1 << 9)
26 #define RTC_SAM2_BIT (1 << 10)
27 #define RTC_SAM3_BIT (1 << 11)
28 #define RTC_SAM4_BIT (1 << 12)
29 #define RTC_SAM5_BIT (1 << 13)
30 #define RTC_SAM6_BIT (1 << 14)
31 #define RTC_SAM7_BIT (1 << 15)
32 #define PIT_ALL_ON (RTC_2HZ_BIT | RTC_SAM0_BIT | RTC_SAM1_BIT | \
33 RTC_SAM2_BIT | RTC_SAM3_BIT | RTC_SAM4_BIT | \
34 RTC_SAM5_BIT | RTC_SAM6_BIT | RTC_SAM7_BIT)
36 #define RTC_ENABLE_BIT (1 << 7)
39 #define MAX_PIE_FREQ 512
41 #define MXC_RTC_TIME 0
42 #define MXC_RTC_ALARM 1
44 #define RTC_HOURMIN 0x00 /* 32bit rtc hour/min counter reg */
45 #define RTC_SECOND 0x04 /* 32bit rtc seconds counter reg */
46 #define RTC_ALRM_HM 0x08 /* 32bit rtc alarm hour/min reg */
47 #define RTC_ALRM_SEC 0x0C /* 32bit rtc alarm seconds reg */
48 #define RTC_RTCCTL 0x10 /* 32bit rtc control reg */
49 #define RTC_RTCISR 0x14 /* 32bit rtc interrupt status reg */
50 #define RTC_RTCIENR 0x18 /* 32bit rtc interrupt enable reg */
51 #define RTC_STPWCH 0x1C /* 32bit rtc stopwatch min reg */
52 #define RTC_DAYR 0x20 /* 32bit rtc days counter reg */
53 #define RTC_DAYALARM 0x24 /* 32bit rtc day alarm reg */
54 #define RTC_TEST1 0x28 /* 32bit rtc test reg 1 */
55 #define RTC_TEST2 0x2C /* 32bit rtc test reg 2 */
56 #define RTC_TEST3 0x30 /* 32bit rtc test reg 3 */
63 struct rtc_plat_data {
64 struct rtc_device *rtc;
69 struct rtc_time g_rtc_alarm;
70 enum imx_rtc_type devtype;
73 static const struct of_device_id imx_rtc_dt_ids[] = {
74 { .compatible = "fsl,imx1-rtc", .data = (const void *)IMX1_RTC },
75 { .compatible = "fsl,imx21-rtc", .data = (const void *)IMX21_RTC },
78 MODULE_DEVICE_TABLE(of, imx_rtc_dt_ids);
80 static inline int is_imx1_rtc(struct rtc_plat_data *data)
82 return data->devtype == IMX1_RTC;
86 * This function is used to obtain the RTC time or the alarm value in
89 static time64_t get_alarm_or_time(struct device *dev, int time_alarm)
91 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
92 void __iomem *ioaddr = pdata->ioaddr;
93 u32 day = 0, hr = 0, min = 0, sec = 0, hr_min = 0;
97 day = readw(ioaddr + RTC_DAYR);
98 hr_min = readw(ioaddr + RTC_HOURMIN);
99 sec = readw(ioaddr + RTC_SECOND);
102 day = readw(ioaddr + RTC_DAYALARM);
103 hr_min = readw(ioaddr + RTC_ALRM_HM) & 0xffff;
104 sec = readw(ioaddr + RTC_ALRM_SEC);
111 return ((((time64_t)day * 24 + hr) * 60) + min) * 60 + sec;
115 * This function sets the RTC alarm value or the time value.
117 static void set_alarm_or_time(struct device *dev, int time_alarm, time64_t time)
119 u32 tod, day, hr, min, sec, temp;
120 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
121 void __iomem *ioaddr = pdata->ioaddr;
123 day = div_s64_rem(time, 86400, &tod);
125 /* time is within a day now */
129 /* time is within an hour now */
131 sec = tod - min * 60;
133 temp = (hr << 8) + min;
135 switch (time_alarm) {
137 writew(day, ioaddr + RTC_DAYR);
138 writew(sec, ioaddr + RTC_SECOND);
139 writew(temp, ioaddr + RTC_HOURMIN);
142 writew(day, ioaddr + RTC_DAYALARM);
143 writew(sec, ioaddr + RTC_ALRM_SEC);
144 writew(temp, ioaddr + RTC_ALRM_HM);
150 * This function updates the RTC alarm registers and then clears all the
151 * interrupt status bits.
153 static void rtc_update_alarm(struct device *dev, struct rtc_time *alrm)
156 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
157 void __iomem *ioaddr = pdata->ioaddr;
159 time = rtc_tm_to_time64(alrm);
161 /* clear all the interrupt status bits */
162 writew(readw(ioaddr + RTC_RTCISR), ioaddr + RTC_RTCISR);
163 set_alarm_or_time(dev, MXC_RTC_ALARM, time);
166 static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
167 unsigned int enabled)
169 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
170 void __iomem *ioaddr = pdata->ioaddr;
174 spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
175 reg = readw(ioaddr + RTC_RTCIENR);
182 writew(reg, ioaddr + RTC_RTCIENR);
183 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
186 /* This function is the RTC interrupt service routine. */
187 static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
189 struct platform_device *pdev = dev_id;
190 struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
191 void __iomem *ioaddr = pdata->ioaddr;
196 spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
197 status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
198 /* clear interrupt sources */
199 writew(status, ioaddr + RTC_RTCISR);
201 /* update irq data & counter */
202 if (status & RTC_ALM_BIT) {
203 events |= (RTC_AF | RTC_IRQF);
204 /* RTC alarm should be one-shot */
205 mxc_rtc_irq_enable(&pdev->dev, RTC_ALM_BIT, 0);
208 if (status & PIT_ALL_ON)
209 events |= (RTC_PF | RTC_IRQF);
211 rtc_update_irq(pdata->rtc, 1, events);
212 spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
217 static int mxc_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
219 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, enabled);
224 * This function reads the current RTC time into tm in Gregorian date.
226 static int mxc_rtc_read_time(struct device *dev, struct rtc_time *tm)
230 /* Avoid roll-over from reading the different registers */
232 val = get_alarm_or_time(dev, MXC_RTC_TIME);
233 } while (val != get_alarm_or_time(dev, MXC_RTC_TIME));
235 rtc_time64_to_tm(val, tm);
241 * This function sets the internal RTC time based on tm in Gregorian date.
243 static int mxc_rtc_set_time(struct device *dev, struct rtc_time *tm)
245 time64_t time = rtc_tm_to_time64(tm);
247 /* Avoid roll-over from reading the different registers */
249 set_alarm_or_time(dev, MXC_RTC_TIME, time);
250 } while (time != get_alarm_or_time(dev, MXC_RTC_TIME));
256 * This function reads the current alarm value into the passed in 'alrm'
257 * argument. It updates the alrm's pending field value based on the whether
258 * an alarm interrupt occurs or not.
260 static int mxc_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
262 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
263 void __iomem *ioaddr = pdata->ioaddr;
265 rtc_time64_to_tm(get_alarm_or_time(dev, MXC_RTC_ALARM), &alrm->time);
266 alrm->pending = ((readw(ioaddr + RTC_RTCISR) & RTC_ALM_BIT)) ? 1 : 0;
272 * This function sets the RTC alarm based on passed in alrm.
274 static int mxc_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
276 struct rtc_plat_data *pdata = dev_get_drvdata(dev);
278 rtc_update_alarm(dev, &alrm->time);
280 memcpy(&pdata->g_rtc_alarm, &alrm->time, sizeof(struct rtc_time));
281 mxc_rtc_irq_enable(dev, RTC_ALM_BIT, alrm->enabled);
287 static const struct rtc_class_ops mxc_rtc_ops = {
288 .read_time = mxc_rtc_read_time,
289 .set_time = mxc_rtc_set_time,
290 .read_alarm = mxc_rtc_read_alarm,
291 .set_alarm = mxc_rtc_set_alarm,
292 .alarm_irq_enable = mxc_rtc_alarm_irq_enable,
295 static void mxc_rtc_action(void *p)
297 struct rtc_plat_data *pdata = p;
299 clk_disable_unprepare(pdata->clk_ref);
300 clk_disable_unprepare(pdata->clk_ipg);
303 static int mxc_rtc_probe(struct platform_device *pdev)
305 struct rtc_device *rtc;
306 struct rtc_plat_data *pdata = NULL;
310 const struct of_device_id *of_id;
312 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
316 of_id = of_match_device(imx_rtc_dt_ids, &pdev->dev);
317 pdata->devtype = (enum imx_rtc_type)of_id->data;
319 pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
320 if (IS_ERR(pdata->ioaddr))
321 return PTR_ERR(pdata->ioaddr);
323 rtc = devm_rtc_allocate_device(&pdev->dev);
328 rtc->ops = &mxc_rtc_ops;
329 if (is_imx1_rtc(pdata)) {
332 /* 9bit days + hours minutes seconds */
333 rtc->range_max = (1 << 9) * 86400 - 1;
336 * Set the start date as beginning of the current year. This can
337 * be overridden using device tree.
339 rtc_time64_to_tm(ktime_get_real_seconds(), &tm);
340 rtc->start_secs = mktime64(tm.tm_year, 1, 1, 0, 0, 0);
341 rtc->set_start_time = true;
343 /* 16bit days + hours minutes seconds */
344 rtc->range_max = (1 << 16) * 86400ULL - 1;
347 pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
348 if (IS_ERR(pdata->clk_ipg)) {
349 dev_err(&pdev->dev, "unable to get ipg clock!\n");
350 return PTR_ERR(pdata->clk_ipg);
353 ret = clk_prepare_enable(pdata->clk_ipg);
357 pdata->clk_ref = devm_clk_get(&pdev->dev, "ref");
358 if (IS_ERR(pdata->clk_ref)) {
359 clk_disable_unprepare(pdata->clk_ipg);
360 dev_err(&pdev->dev, "unable to get ref clock!\n");
361 return PTR_ERR(pdata->clk_ref);
364 ret = clk_prepare_enable(pdata->clk_ref);
366 clk_disable_unprepare(pdata->clk_ipg);
370 ret = devm_add_action_or_reset(&pdev->dev, mxc_rtc_action, pdata);
374 rate = clk_get_rate(pdata->clk_ref);
377 reg = RTC_INPUT_CLK_32768HZ;
378 else if (rate == 32000)
379 reg = RTC_INPUT_CLK_32000HZ;
380 else if (rate == 38400)
381 reg = RTC_INPUT_CLK_38400HZ;
383 dev_err(&pdev->dev, "rtc clock is not valid (%lu)\n", rate);
387 reg |= RTC_ENABLE_BIT;
388 writew(reg, (pdata->ioaddr + RTC_RTCCTL));
389 if (((readw(pdata->ioaddr + RTC_RTCCTL)) & RTC_ENABLE_BIT) == 0) {
390 dev_err(&pdev->dev, "hardware module can't be enabled!\n");
394 platform_set_drvdata(pdev, pdata);
396 /* Configure and enable the RTC */
397 pdata->irq = platform_get_irq(pdev, 0);
399 if (pdata->irq >= 0 &&
400 devm_request_irq(&pdev->dev, pdata->irq, mxc_rtc_interrupt,
401 IRQF_SHARED, pdev->name, pdev) < 0) {
402 dev_warn(&pdev->dev, "interrupt not available.\n");
406 if (pdata->irq >= 0) {
407 device_init_wakeup(&pdev->dev, 1);
408 ret = dev_pm_set_wake_irq(&pdev->dev, pdata->irq);
410 dev_err(&pdev->dev, "failed to enable irq wake\n");
413 ret = rtc_register_device(rtc);
418 static struct platform_driver mxc_rtc_driver = {
421 .of_match_table = of_match_ptr(imx_rtc_dt_ids),
423 .probe = mxc_rtc_probe,
426 module_platform_driver(mxc_rtc_driver)
428 MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
429 MODULE_DESCRIPTION("RTC driver for Freescale MXC");
430 MODULE_LICENSE("GPL");