1 // SPDX-License-Identifier: GPL-2.0
3  * Texas Instruments K3 RTC driver
5  * Copyright (C) 2021-2022 Texas Instruments Incorporated - https://www.ti.com/
17 #include <linux/rtc.h>
46 #define K3RTC_MIN_OFFSET		(-277761)
50 	.name = "peripheral-registers",
107  * struct ti_k3_rtc - Private data for ti-k3-rtc
111  * @rtc_dev:		rtc device
112  * @regmap:		rtc mmio regmap
113  * @r_fields:		rtc register fields
129 	ret = regmap_field_read(priv->r_fields[f], &val);  in k3rtc_field_read()
141 	regmap_field_write(priv->r_fields[f], val);  in k3rtc_field_write()
145  * k3rtc_fence  - Ensure a register sync took place between the two domains
148  * Return: 0 if the sync took place, else returns -ETIMEDOUT
154 	ret = regmap_field_read_poll_timeout(priv->r_fields[K3RTC_PEND], ret,  in k3rtc_fence()
155 					     !ret, 2, priv->sync_timeout_us);  in k3rtc_fence()
183 	ret = regmap_field_read_poll_timeout(priv->r_fields[K3RTC_UNLOCK], ret,  in k3rtc_unlock_rtc()
184 					     ret, 2, priv->sync_timeout_us);  in k3rtc_unlock_rtc()
190  * This is the list of SoCs affected by TI's i2327 errata causing the RTC
191  * state-machine to break if not unlocked fast enough during boot. These
193  * boot-flow before we (Linux) can use this device.
206 	 * HWBUG: The compare state machine is broken if the RTC module  in k3rtc_configure()
207 	 * is NOT unlocked in under one second of boot - which is pretty long  in k3rtc_configure()
208 	 * time from the perspective of Linux driver (module load, u-boot  in k3rtc_configure()
211 	 * In such occurrence, it is assumed that the RTC module is unusable  in k3rtc_configure()
219 			return -EFAULT;  in k3rtc_configure()
237 	usleep_range(priv->sync_timeout_us, priv->sync_timeout_us + 5);  in k3rtc_configure()
243 			"Failed fence osc_dep enable(%d) - is 32k clk working?!\n", ret);  in k3rtc_configure()
286 	 * Read operation on LSW will freeze the RTC, so to update  in ti_k3_rtc_set_time()
290 	regmap_write(priv->regmap, REG_K3RTC_S_CNT_LSW, seconds);  in ti_k3_rtc_set_time()
291 	regmap_write(priv->regmap, REG_K3RTC_S_CNT_MSW, seconds >> 32);  in ti_k3_rtc_set_time()
309 	 * Ensure the write sync is through - NOTE: it should be OK to have  in ti_k3_rtc_alarm_irq_enable()
324 	rtc_time64_to_tm((((time64_t)seconds_hi) << 32) | (time64_t)seconds_lo, &alarm->time);  in ti_k3_rtc_read_alarm()
326 	alarm->enabled = k3rtc_field_read(priv, K3RTC_IRQ_ENABLE_SET);  in ti_k3_rtc_read_alarm()
337 	seconds = rtc_tm_to_time64(&alarm->time);  in ti_k3_rtc_set_alarm()
350 	return ti_k3_rtc_alarm_irq_enable(dev, alarm->enabled);  in ti_k3_rtc_set_alarm()
356 	u32 ticks_per_hr = priv->rate_32k * 3600;  in ti_k3_rtc_read_offset()
362 	/* Convert from RTC calibration register format to ppb format */  in ti_k3_rtc_read_offset()
365 		tmp -= ticks_per_hr / 2LL;  in ti_k3_rtc_read_offset()
371 	*offset = (long)-tmp;  in ti_k3_rtc_read_offset()
379 	u32 ticks_per_hr = priv->rate_32k * 3600;  in ti_k3_rtc_set_offset()
385 		return -ERANGE;  in ti_k3_rtc_set_offset()
387 	/* Convert from ppb format to RTC calibration register format */  in ti_k3_rtc_set_offset()
390 		tmp -= K3RTC_PPB_MULT / 2LL;  in ti_k3_rtc_set_offset()
396 	comp = (int)-tmp;  in ti_k3_rtc_set_offset()
412 	 * de-assert depends on 32k clock edge in the 32k domain  in ti_k3_rtc_interrupt()
414 	 * the status bit is cleared, but the IRQ stays re-asserted.  in ti_k3_rtc_interrupt()
421 	usleep_range(priv->sync_timeout_us, priv->sync_timeout_us + 2);  in ti_k3_rtc_interrupt()
440 	regmap_write(priv->regmap, REG_K3RTC_IRQSTATUS_SYS, 0x1);  in ti_k3_rtc_interrupt()
463 	ret = regmap_field_read_poll_timeout(priv->r_fields[K3RTC_IRQ_STATUS],  in ti_k3_rtc_interrupt()
464 					     ret, !ret, 2, priv->sync_timeout_us);  in ti_k3_rtc_interrupt()
470 	/* Notify RTC core on event */  in ti_k3_rtc_interrupt()
471 	rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF);  in ti_k3_rtc_interrupt()
491 	return regmap_bulk_read(priv->regmap, REG_K3RTC_SCRATCH0 + offset, val, bytes / 4);  in ti_k3_rtc_scratch_read()
500 	ret = regmap_bulk_write(priv->regmap, REG_K3RTC_SCRATCH0 + offset, val, bytes / 4);  in ti_k3_rtc_scratch_write()
511 	.size = REG_K3RTC_SCRATCH7 - REG_K3RTC_SCRATCH0 + 4,
524 	priv->rate_32k = clk_get_rate(clk);  in k3rtc_get_32kclk()
527 	if (priv->rate_32k != 32768)  in k3rtc_get_32kclk()
529 			 priv->rate_32k);  in k3rtc_get_32kclk()
536 	priv->sync_timeout_us = (u32)(DIV_ROUND_UP_ULL(1000000, priv->rate_32k) * 4);  in k3rtc_get_32kclk()
555 	struct device *dev = &pdev->dev;  in ti_k3_rtc_probe()
562 		return -ENOMEM;  in ti_k3_rtc_probe()
568 	priv->regmap = devm_regmap_init_mmio(dev, rtc_base, &ti_k3_rtc_regmap_config);  in ti_k3_rtc_probe()
569 	if (IS_ERR(priv->regmap))  in ti_k3_rtc_probe()
570 		return PTR_ERR(priv->regmap);  in ti_k3_rtc_probe()
572 	ret = devm_regmap_field_bulk_alloc(dev, priv->regmap, priv->r_fields,  in ti_k3_rtc_probe()
587 	priv->irq = (unsigned int)ret;  in ti_k3_rtc_probe()
589 	priv->rtc_dev = devm_rtc_allocate_device(dev);  in ti_k3_rtc_probe()
590 	if (IS_ERR(priv->rtc_dev))  in ti_k3_rtc_probe()
591 		return PTR_ERR(priv->rtc_dev);  in ti_k3_rtc_probe()
593 	priv->rtc_dev->ops = &ti_k3_rtc_ops;  in ti_k3_rtc_probe()
594 	priv->rtc_dev->range_max = (1ULL << 48) - 1;	/* 48Bit seconds */  in ti_k3_rtc_probe()
597 	ret = devm_request_threaded_irq(dev, priv->irq, NULL,  in ti_k3_rtc_probe()
612 	if (device_property_present(dev, "wakeup-source"))  in ti_k3_rtc_probe()
617 	ret = devm_rtc_register_device(priv->rtc_dev);  in ti_k3_rtc_probe()
621 	return devm_rtc_nvmem_register(priv->rtc_dev, &ti_k3_rtc_nvmem_config);  in ti_k3_rtc_probe()
625 	{.compatible = "ti,am62-rtc" },
635 		return enable_irq_wake(priv->irq);  in ti_k3_rtc_suspend()
645 		disable_irq_wake(priv->irq);  in ti_k3_rtc_resume()
654 		   .name = "rtc-ti-k3",
662 MODULE_DESCRIPTION("TI K3 RTC driver");