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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * An RTC driver for Allwinner A31/A234 *5 * Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>6 *7 * based on rtc-sunxi.c8 *9 * An RTC driver for Allwinner A10/A2010 *11 * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>12 */13 14#include <linux/clk.h>15#include <linux/clk-provider.h>16#include <linux/clk/sunxi-ng.h>17#include <linux/delay.h>18#include <linux/err.h>19#include <linux/fs.h>20#include <linux/init.h>21#include <linux/interrupt.h>22#include <linux/io.h>23#include <linux/kernel.h>24#include <linux/module.h>25#include <linux/of.h>26#include <linux/of_address.h>27#include <linux/platform_device.h>28#include <linux/rtc.h>29#include <linux/slab.h>30#include <linux/types.h>31 32/* Control register */33#define SUN6I_LOSC_CTRL				0x000034#define SUN6I_LOSC_CTRL_KEY			(0x16aa << 16)35#define SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS		BIT(15)36#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC		BIT(9)37#define SUN6I_LOSC_CTRL_RTC_HMS_ACC		BIT(8)38#define SUN6I_LOSC_CTRL_RTC_YMD_ACC		BIT(7)39#define SUN6I_LOSC_CTRL_EXT_LOSC_EN		BIT(4)40#define SUN6I_LOSC_CTRL_EXT_OSC			BIT(0)41#define SUN6I_LOSC_CTRL_ACC_MASK		GENMASK(9, 7)42 43#define SUN6I_LOSC_CLK_PRESCAL			0x000844 45/* RTC */46#define SUN6I_RTC_YMD				0x001047#define SUN6I_RTC_HMS				0x001448 49/* Alarm 0 (counter) */50#define SUN6I_ALRM_COUNTER			0x002051/* This holds the remaining alarm seconds on older SoCs (current value) */52#define SUN6I_ALRM_COUNTER_HMS			0x002453#define SUN6I_ALRM_EN				0x002854#define SUN6I_ALRM_EN_CNT_EN			BIT(0)55#define SUN6I_ALRM_IRQ_EN			0x002c56#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN		BIT(0)57#define SUN6I_ALRM_IRQ_STA			0x003058#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND		BIT(0)59 60/* Alarm 1 (wall clock) */61#define SUN6I_ALRM1_EN				0x004462#define SUN6I_ALRM1_IRQ_EN			0x004863#define SUN6I_ALRM1_IRQ_STA			0x004c64#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND	BIT(0)65 66/* Alarm config */67#define SUN6I_ALARM_CONFIG			0x005068#define SUN6I_ALARM_CONFIG_WAKEUP		BIT(0)69 70#define SUN6I_LOSC_OUT_GATING			0x006071#define SUN6I_LOSC_OUT_GATING_EN_OFFSET		072 73/* General-purpose data */74#define SUN6I_GP_DATA				0x010075#define SUN6I_GP_DATA_SIZE			0x2076 77/*78 * Get date values79 */80#define SUN6I_DATE_GET_DAY_VALUE(x)		((x)  & 0x0000001f)81#define SUN6I_DATE_GET_MON_VALUE(x)		(((x) & 0x00000f00) >> 8)82#define SUN6I_DATE_GET_YEAR_VALUE(x)		(((x) & 0x003f0000) >> 16)83#define SUN6I_LEAP_GET_VALUE(x)			(((x) & 0x00400000) >> 22)84 85/*86 * Get time values87 */88#define SUN6I_TIME_GET_SEC_VALUE(x)		((x)  & 0x0000003f)89#define SUN6I_TIME_GET_MIN_VALUE(x)		(((x) & 0x00003f00) >> 8)90#define SUN6I_TIME_GET_HOUR_VALUE(x)		(((x) & 0x001f0000) >> 16)91 92/*93 * Set date values94 */95#define SUN6I_DATE_SET_DAY_VALUE(x)		((x)       & 0x0000001f)96#define SUN6I_DATE_SET_MON_VALUE(x)		((x) <<  8 & 0x00000f00)97#define SUN6I_DATE_SET_YEAR_VALUE(x)		((x) << 16 & 0x003f0000)98#define SUN6I_LEAP_SET_VALUE(x)			((x) << 22 & 0x00400000)99 100/*101 * Set time values102 */103#define SUN6I_TIME_SET_SEC_VALUE(x)		((x)       & 0x0000003f)104#define SUN6I_TIME_SET_MIN_VALUE(x)		((x) <<  8 & 0x00003f00)105#define SUN6I_TIME_SET_HOUR_VALUE(x)		((x) << 16 & 0x001f0000)106 107/*108 * The year parameter passed to the driver is usually an offset relative to109 * the year 1900. This macro is used to convert this offset to another one110 * relative to the minimum year allowed by the hardware.111 *112 * The year range is 1970 - 2033. This range is selected to match Allwinner's113 * driver, even though it is somewhat limited.114 */115#define SUN6I_YEAR_MIN				1970116#define SUN6I_YEAR_OFF				(SUN6I_YEAR_MIN - 1900)117 118#define SECS_PER_DAY				(24 * 3600ULL)119 120/*121 * There are other differences between models, including:122 *123 *   - number of GPIO pins that can be configured to hold a certain level124 *   - crypto-key related registers (H5, H6)125 *   - boot process related (super standby, secondary processor entry address)126 *     registers (R40, H6)127 *   - SYS power domain controls (R40)128 *   - DCXO controls (H6)129 *   - RC oscillator calibration (H6)130 *131 * These functions are not covered by this driver.132 */133struct sun6i_rtc_clk_data {134	unsigned long rc_osc_rate;135	unsigned int fixed_prescaler : 16;136	unsigned int has_prescaler : 1;137	unsigned int has_out_clk : 1;138	unsigned int has_losc_en : 1;139	unsigned int has_auto_swt : 1;140};141 142#define RTC_LINEAR_DAY	BIT(0)143 144struct sun6i_rtc_dev {145	struct rtc_device *rtc;146	const struct sun6i_rtc_clk_data *data;147	void __iomem *base;148	int irq;149	time64_t alarm;150	unsigned long flags;151 152	struct clk_hw hw;153	struct clk_hw *int_osc;154	struct clk *losc;155	struct clk *ext_losc;156 157	spinlock_t lock;158};159 160static struct sun6i_rtc_dev *sun6i_rtc;161 162static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,163					       unsigned long parent_rate)164{165	struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);166	u32 val = 0;167 168	val = readl(rtc->base + SUN6I_LOSC_CTRL);169	if (val & SUN6I_LOSC_CTRL_EXT_OSC)170		return parent_rate;171 172	if (rtc->data->fixed_prescaler)173		parent_rate /= rtc->data->fixed_prescaler;174 175	if (rtc->data->has_prescaler) {176		val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);177		val &= GENMASK(4, 0);178	}179 180	return parent_rate / (val + 1);181}182 183static u8 sun6i_rtc_osc_get_parent(struct clk_hw *hw)184{185	struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);186 187	return readl(rtc->base + SUN6I_LOSC_CTRL) & SUN6I_LOSC_CTRL_EXT_OSC;188}189 190static int sun6i_rtc_osc_set_parent(struct clk_hw *hw, u8 index)191{192	struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);193	unsigned long flags;194	u32 val;195 196	if (index > 1)197		return -EINVAL;198 199	spin_lock_irqsave(&rtc->lock, flags);200	val = readl(rtc->base + SUN6I_LOSC_CTRL);201	val &= ~SUN6I_LOSC_CTRL_EXT_OSC;202	val |= SUN6I_LOSC_CTRL_KEY;203	val |= index ? SUN6I_LOSC_CTRL_EXT_OSC : 0;204	if (rtc->data->has_losc_en) {205		val &= ~SUN6I_LOSC_CTRL_EXT_LOSC_EN;206		val |= index ? SUN6I_LOSC_CTRL_EXT_LOSC_EN : 0;207	}208	writel(val, rtc->base + SUN6I_LOSC_CTRL);209	spin_unlock_irqrestore(&rtc->lock, flags);210 211	return 0;212}213 214static const struct clk_ops sun6i_rtc_osc_ops = {215	.recalc_rate	= sun6i_rtc_osc_recalc_rate,216	.determine_rate	= clk_hw_determine_rate_no_reparent,217 218	.get_parent	= sun6i_rtc_osc_get_parent,219	.set_parent	= sun6i_rtc_osc_set_parent,220};221 222static void __init sun6i_rtc_clk_init(struct device_node *node,223				      const struct sun6i_rtc_clk_data *data)224{225	struct clk_hw_onecell_data *clk_data;226	struct sun6i_rtc_dev *rtc;227	struct clk_init_data init = {228		.ops		= &sun6i_rtc_osc_ops,229		.name		= "losc",230	};231	const char *iosc_name = "rtc-int-osc";232	const char *clkout_name = "osc32k-out";233	const char *parents[2];234	u32 reg;235 236	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);237	if (!rtc)238		return;239 240	rtc->data = data;241	clk_data = kzalloc(struct_size(clk_data, hws, 3), GFP_KERNEL);242	if (!clk_data) {243		kfree(rtc);244		return;245	}246 247	spin_lock_init(&rtc->lock);248 249	rtc->base = of_io_request_and_map(node, 0, of_node_full_name(node));250	if (IS_ERR(rtc->base)) {251		pr_crit("Can't map RTC registers");252		goto err;253	}254 255	reg = SUN6I_LOSC_CTRL_KEY;256	if (rtc->data->has_auto_swt) {257		/* Bypass auto-switch to int osc, on ext losc failure */258		reg |= SUN6I_LOSC_CTRL_AUTO_SWT_BYPASS;259		writel(reg, rtc->base + SUN6I_LOSC_CTRL);260	}261 262	/* Switch to the external, more precise, oscillator, if present */263	if (of_property_present(node, "clocks")) {264		reg |= SUN6I_LOSC_CTRL_EXT_OSC;265		if (rtc->data->has_losc_en)266			reg |= SUN6I_LOSC_CTRL_EXT_LOSC_EN;267	}268	writel(reg, rtc->base + SUN6I_LOSC_CTRL);269 270	/* Yes, I know, this is ugly. */271	sun6i_rtc = rtc;272 273	of_property_read_string_index(node, "clock-output-names", 2,274				      &iosc_name);275 276	rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,277								iosc_name,278								NULL, 0,279								rtc->data->rc_osc_rate,280								300000000);281	if (IS_ERR(rtc->int_osc)) {282		pr_crit("Couldn't register the internal oscillator\n");283		goto err;284	}285 286	parents[0] = clk_hw_get_name(rtc->int_osc);287	/* If there is no external oscillator, this will be NULL and ... */288	parents[1] = of_clk_get_parent_name(node, 0);289 290	rtc->hw.init = &init;291 292	init.parent_names = parents;293	/* ... number of clock parents will be 1. */294	init.num_parents = of_clk_get_parent_count(node) + 1;295	of_property_read_string_index(node, "clock-output-names", 0,296				      &init.name);297 298	rtc->losc = clk_register(NULL, &rtc->hw);299	if (IS_ERR(rtc->losc)) {300		pr_crit("Couldn't register the LOSC clock\n");301		goto err_register;302	}303 304	of_property_read_string_index(node, "clock-output-names", 1,305				      &clkout_name);306	rtc->ext_losc = clk_register_gate(NULL, clkout_name, init.name,307					  0, rtc->base + SUN6I_LOSC_OUT_GATING,308					  SUN6I_LOSC_OUT_GATING_EN_OFFSET, 0,309					  &rtc->lock);310	if (IS_ERR(rtc->ext_losc)) {311		pr_crit("Couldn't register the LOSC external gate\n");312		goto err_register;313	}314 315	clk_data->num = 3;316	clk_data->hws[0] = &rtc->hw;317	clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);318	clk_data->hws[2] = rtc->int_osc;319	of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);320	return;321 322err_register:323	clk_hw_unregister_fixed_rate(rtc->int_osc);324err:325	kfree(clk_data);326}327 328static const struct sun6i_rtc_clk_data sun6i_a31_rtc_data = {329	.rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */330	.has_prescaler = 1,331};332 333static void __init sun6i_a31_rtc_clk_init(struct device_node *node)334{335	sun6i_rtc_clk_init(node, &sun6i_a31_rtc_data);336}337CLK_OF_DECLARE_DRIVER(sun6i_a31_rtc_clk, "allwinner,sun6i-a31-rtc",338		      sun6i_a31_rtc_clk_init);339 340static const struct sun6i_rtc_clk_data sun8i_a23_rtc_data = {341	.rc_osc_rate = 667000, /* datasheet says 600 ~ 700 KHz */342	.has_prescaler = 1,343	.has_out_clk = 1,344};345 346static void __init sun8i_a23_rtc_clk_init(struct device_node *node)347{348	sun6i_rtc_clk_init(node, &sun8i_a23_rtc_data);349}350CLK_OF_DECLARE_DRIVER(sun8i_a23_rtc_clk, "allwinner,sun8i-a23-rtc",351		      sun8i_a23_rtc_clk_init);352 353static const struct sun6i_rtc_clk_data sun8i_h3_rtc_data = {354	.rc_osc_rate = 16000000,355	.fixed_prescaler = 32,356	.has_prescaler = 1,357	.has_out_clk = 1,358};359 360static void __init sun8i_h3_rtc_clk_init(struct device_node *node)361{362	sun6i_rtc_clk_init(node, &sun8i_h3_rtc_data);363}364CLK_OF_DECLARE_DRIVER(sun8i_h3_rtc_clk, "allwinner,sun8i-h3-rtc",365		      sun8i_h3_rtc_clk_init);366/* As far as we are concerned, clocks for H5 are the same as H3 */367CLK_OF_DECLARE_DRIVER(sun50i_h5_rtc_clk, "allwinner,sun50i-h5-rtc",368		      sun8i_h3_rtc_clk_init);369 370static const struct sun6i_rtc_clk_data sun50i_h6_rtc_data = {371	.rc_osc_rate = 16000000,372	.fixed_prescaler = 32,373	.has_prescaler = 1,374	.has_out_clk = 1,375	.has_losc_en = 1,376	.has_auto_swt = 1,377};378 379static void __init sun50i_h6_rtc_clk_init(struct device_node *node)380{381	sun6i_rtc_clk_init(node, &sun50i_h6_rtc_data);382}383CLK_OF_DECLARE_DRIVER(sun50i_h6_rtc_clk, "allwinner,sun50i-h6-rtc",384		      sun50i_h6_rtc_clk_init);385 386/*387 * The R40 user manual is self-conflicting on whether the prescaler is388 * fixed or configurable. The clock diagram shows it as fixed, but there389 * is also a configurable divider in the RTC block.390 */391static const struct sun6i_rtc_clk_data sun8i_r40_rtc_data = {392	.rc_osc_rate = 16000000,393	.fixed_prescaler = 512,394};395static void __init sun8i_r40_rtc_clk_init(struct device_node *node)396{397	sun6i_rtc_clk_init(node, &sun8i_r40_rtc_data);398}399CLK_OF_DECLARE_DRIVER(sun8i_r40_rtc_clk, "allwinner,sun8i-r40-rtc",400		      sun8i_r40_rtc_clk_init);401 402static const struct sun6i_rtc_clk_data sun8i_v3_rtc_data = {403	.rc_osc_rate = 32000,404	.has_out_clk = 1,405	.has_auto_swt = 1,406};407 408static void __init sun8i_v3_rtc_clk_init(struct device_node *node)409{410	sun6i_rtc_clk_init(node, &sun8i_v3_rtc_data);411}412CLK_OF_DECLARE_DRIVER(sun8i_v3_rtc_clk, "allwinner,sun8i-v3-rtc",413		      sun8i_v3_rtc_clk_init);414 415static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)416{417	struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;418	irqreturn_t ret = IRQ_NONE;419	u32 val;420 421	spin_lock(&chip->lock);422	val = readl(chip->base + SUN6I_ALRM_IRQ_STA);423 424	if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {425		val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;426		writel(val, chip->base + SUN6I_ALRM_IRQ_STA);427 428		rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);429 430		ret = IRQ_HANDLED;431	}432	spin_unlock(&chip->lock);433 434	return ret;435}436 437static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)438{439	u32 alrm_val = 0;440	u32 alrm_irq_val = 0;441	u32 alrm_wake_val = 0;442	unsigned long flags;443 444	if (to) {445		alrm_val = SUN6I_ALRM_EN_CNT_EN;446		alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;447		alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;448	} else {449		writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,450		       chip->base + SUN6I_ALRM_IRQ_STA);451	}452 453	spin_lock_irqsave(&chip->lock, flags);454	writel(alrm_val, chip->base + SUN6I_ALRM_EN);455	writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);456	writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);457	spin_unlock_irqrestore(&chip->lock, flags);458}459 460static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)461{462	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);463	u32 date, time;464 465	/*466	 * read again in case it changes467	 */468	do {469		date = readl(chip->base + SUN6I_RTC_YMD);470		time = readl(chip->base + SUN6I_RTC_HMS);471	} while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||472		 (time != readl(chip->base + SUN6I_RTC_HMS)));473 474	if (chip->flags & RTC_LINEAR_DAY) {475		/*476		 * Newer chips store a linear day number, the manual477		 * does not mandate any epoch base. The BSP driver uses478		 * the UNIX epoch, let's just copy that, as it's the479		 * easiest anyway.480		 */481		rtc_time64_to_tm((date & 0xffff) * SECS_PER_DAY, rtc_tm);482	} else {483		rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);484		rtc_tm->tm_mon  = SUN6I_DATE_GET_MON_VALUE(date) - 1;485		rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);486 487		/*488		 * switch from (data_year->min)-relative offset to489		 * a (1900)-relative one490		 */491		rtc_tm->tm_year += SUN6I_YEAR_OFF;492	}493 494	rtc_tm->tm_sec  = SUN6I_TIME_GET_SEC_VALUE(time);495	rtc_tm->tm_min  = SUN6I_TIME_GET_MIN_VALUE(time);496	rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);497 498	return 0;499}500 501static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)502{503	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);504	unsigned long flags;505	u32 alrm_st;506	u32 alrm_en;507 508	spin_lock_irqsave(&chip->lock, flags);509	alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);510	alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);511	spin_unlock_irqrestore(&chip->lock, flags);512 513	wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);514	wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);515	rtc_time64_to_tm(chip->alarm, &wkalrm->time);516 517	return 0;518}519 520static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)521{522	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);523	struct rtc_time *alrm_tm = &wkalrm->time;524	struct rtc_time tm_now;525	time64_t time_set;526	u32 counter_val, counter_val_hms;527	int ret;528 529	time_set = rtc_tm_to_time64(alrm_tm);530 531	if (chip->flags & RTC_LINEAR_DAY) {532		/*533		 * The alarm registers hold the actual alarm time, encoded534		 * in the same way (linear day + HMS) as the current time.535		 */536		counter_val_hms = SUN6I_TIME_SET_SEC_VALUE(alrm_tm->tm_sec)  |537				  SUN6I_TIME_SET_MIN_VALUE(alrm_tm->tm_min)  |538				  SUN6I_TIME_SET_HOUR_VALUE(alrm_tm->tm_hour);539		/* The division will cut off the H:M:S part of alrm_tm. */540		counter_val = div_u64(rtc_tm_to_time64(alrm_tm), SECS_PER_DAY);541	} else {542		/* The alarm register holds the number of seconds left. */543		time64_t time_now;544 545		ret = sun6i_rtc_gettime(dev, &tm_now);546		if (ret < 0) {547			dev_err(dev, "Error in getting time\n");548			return -EINVAL;549		}550 551		time_now = rtc_tm_to_time64(&tm_now);552		if (time_set <= time_now) {553			dev_err(dev, "Date to set in the past\n");554			return -EINVAL;555		}556		if ((time_set - time_now) > U32_MAX) {557			dev_err(dev, "Date too far in the future\n");558			return -EINVAL;559		}560 561		counter_val = time_set - time_now;562	}563 564	sun6i_rtc_setaie(0, chip);565	writel(0, chip->base + SUN6I_ALRM_COUNTER);566	if (chip->flags & RTC_LINEAR_DAY)567		writel(0, chip->base + SUN6I_ALRM_COUNTER_HMS);568	usleep_range(100, 300);569 570	writel(counter_val, chip->base + SUN6I_ALRM_COUNTER);571	if (chip->flags & RTC_LINEAR_DAY)572		writel(counter_val_hms, chip->base + SUN6I_ALRM_COUNTER_HMS);573	chip->alarm = time_set;574 575	sun6i_rtc_setaie(wkalrm->enabled, chip);576 577	return 0;578}579 580static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,581			  unsigned int mask, unsigned int ms_timeout)582{583	const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);584	u32 reg;585 586	do {587		reg = readl(chip->base + offset);588		reg &= mask;589 590		if (!reg)591			return 0;592 593	} while (time_before(jiffies, timeout));594 595	return -ETIMEDOUT;596}597 598static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)599{600	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);601	u32 date = 0;602	u32 time = 0;603 604	time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec)  |605		SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min)  |606		SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);607 608	if (chip->flags & RTC_LINEAR_DAY) {609		/* The division will cut off the H:M:S part of rtc_tm. */610		date = div_u64(rtc_tm_to_time64(rtc_tm), SECS_PER_DAY);611	} else {612		rtc_tm->tm_year -= SUN6I_YEAR_OFF;613		rtc_tm->tm_mon += 1;614 615		date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |616			SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon)  |617			SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);618 619		if (is_leap_year(rtc_tm->tm_year + SUN6I_YEAR_MIN))620			date |= SUN6I_LEAP_SET_VALUE(1);621	}622 623	/* Check whether registers are writable */624	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,625			   SUN6I_LOSC_CTRL_ACC_MASK, 50)) {626		dev_err(dev, "rtc is still busy.\n");627		return -EBUSY;628	}629 630	writel(time, chip->base + SUN6I_RTC_HMS);631 632	/*633	 * After writing the RTC HH-MM-SS register, the634	 * SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not635	 * be cleared until the real writing operation is finished636	 */637 638	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,639			   SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {640		dev_err(dev, "Failed to set rtc time.\n");641		return -ETIMEDOUT;642	}643 644	writel(date, chip->base + SUN6I_RTC_YMD);645 646	/*647	 * After writing the RTC YY-MM-DD register, the648	 * SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not649	 * be cleared until the real writing operation is finished650	 */651 652	if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,653			   SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {654		dev_err(dev, "Failed to set rtc time.\n");655		return -ETIMEDOUT;656	}657 658	return 0;659}660 661static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)662{663	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);664 665	if (!enabled)666		sun6i_rtc_setaie(enabled, chip);667 668	return 0;669}670 671static const struct rtc_class_ops sun6i_rtc_ops = {672	.read_time		= sun6i_rtc_gettime,673	.set_time		= sun6i_rtc_settime,674	.read_alarm		= sun6i_rtc_getalarm,675	.set_alarm		= sun6i_rtc_setalarm,676	.alarm_irq_enable	= sun6i_rtc_alarm_irq_enable677};678 679static int sun6i_rtc_nvmem_read(void *priv, unsigned int offset, void *_val, size_t bytes)680{681	struct sun6i_rtc_dev *chip = priv;682	u32 *val = _val;683	int i;684 685	for (i = 0; i < bytes / 4; ++i)686		val[i] = readl(chip->base + SUN6I_GP_DATA + offset + 4 * i);687 688	return 0;689}690 691static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, void *_val, size_t bytes)692{693	struct sun6i_rtc_dev *chip = priv;694	u32 *val = _val;695	int i;696 697	for (i = 0; i < bytes / 4; ++i)698		writel(val[i], chip->base + SUN6I_GP_DATA + offset + 4 * i);699 700	return 0;701}702 703static struct nvmem_config sun6i_rtc_nvmem_cfg = {704	.type		= NVMEM_TYPE_BATTERY_BACKED,705	.reg_read	= sun6i_rtc_nvmem_read,706	.reg_write	= sun6i_rtc_nvmem_write,707	.size		= SUN6I_GP_DATA_SIZE,708	.word_size	= 4,709	.stride		= 4,710};711 712#ifdef CONFIG_PM_SLEEP713/* Enable IRQ wake on suspend, to wake up from RTC. */714static int sun6i_rtc_suspend(struct device *dev)715{716	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);717 718	if (device_may_wakeup(dev))719		enable_irq_wake(chip->irq);720 721	return 0;722}723 724/* Disable IRQ wake on resume. */725static int sun6i_rtc_resume(struct device *dev)726{727	struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);728 729	if (device_may_wakeup(dev))730		disable_irq_wake(chip->irq);731 732	return 0;733}734#endif735 736static SIMPLE_DEV_PM_OPS(sun6i_rtc_pm_ops,737	sun6i_rtc_suspend, sun6i_rtc_resume);738 739static void sun6i_rtc_bus_clk_cleanup(void *data)740{741	struct clk *bus_clk = data;742 743	clk_disable_unprepare(bus_clk);744}745 746static int sun6i_rtc_probe(struct platform_device *pdev)747{748	struct sun6i_rtc_dev *chip = sun6i_rtc;749	struct device *dev = &pdev->dev;750	struct clk *bus_clk;751	int ret;752 753	bus_clk = devm_clk_get_optional(dev, "bus");754	if (IS_ERR(bus_clk))755		return PTR_ERR(bus_clk);756 757	if (bus_clk) {758		ret = clk_prepare_enable(bus_clk);759		if (ret)760			return ret;761 762		ret = devm_add_action_or_reset(dev, sun6i_rtc_bus_clk_cleanup,763					       bus_clk);764		if (ret)765			return ret;766	}767 768	if (!chip) {769		chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);770		if (!chip)771			return -ENOMEM;772 773		spin_lock_init(&chip->lock);774 775		chip->base = devm_platform_ioremap_resource(pdev, 0);776		if (IS_ERR(chip->base))777			return PTR_ERR(chip->base);778 779		if (IS_REACHABLE(CONFIG_SUN6I_RTC_CCU)) {780			ret = sun6i_rtc_ccu_probe(dev, chip->base);781			if (ret)782				return ret;783		}784	}785 786	platform_set_drvdata(pdev, chip);787 788	chip->flags = (unsigned long)of_device_get_match_data(&pdev->dev);789 790	chip->irq = platform_get_irq(pdev, 0);791	if (chip->irq < 0)792		return chip->irq;793 794	ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,795			       0, dev_name(&pdev->dev), chip);796	if (ret) {797		dev_err(&pdev->dev, "Could not request IRQ\n");798		return ret;799	}800 801	/* clear the alarm counter value */802	writel(0, chip->base + SUN6I_ALRM_COUNTER);803 804	/* disable counter alarm */805	writel(0, chip->base + SUN6I_ALRM_EN);806 807	/* disable counter alarm interrupt */808	writel(0, chip->base + SUN6I_ALRM_IRQ_EN);809 810	/* disable week alarm */811	writel(0, chip->base + SUN6I_ALRM1_EN);812 813	/* disable week alarm interrupt */814	writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);815 816	/* clear counter alarm pending interrupts */817	writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,818	       chip->base + SUN6I_ALRM_IRQ_STA);819 820	/* clear week alarm pending interrupts */821	writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,822	       chip->base + SUN6I_ALRM1_IRQ_STA);823 824	/* disable alarm wakeup */825	writel(0, chip->base + SUN6I_ALARM_CONFIG);826 827	clk_prepare_enable(chip->losc);828 829	device_init_wakeup(&pdev->dev, 1);830 831	chip->rtc = devm_rtc_allocate_device(&pdev->dev);832	if (IS_ERR(chip->rtc))833		return PTR_ERR(chip->rtc);834 835	chip->rtc->ops = &sun6i_rtc_ops;836	if (chip->flags & RTC_LINEAR_DAY)837		chip->rtc->range_max = (65536 * SECS_PER_DAY) - 1;838	else839		chip->rtc->range_max = 2019686399LL; /* 2033-12-31 23:59:59 */840 841	ret = devm_rtc_register_device(chip->rtc);842	if (ret)843		return ret;844 845	sun6i_rtc_nvmem_cfg.priv = chip;846	ret = devm_rtc_nvmem_register(chip->rtc, &sun6i_rtc_nvmem_cfg);847	if (ret)848		return ret;849 850	return 0;851}852 853/*854 * As far as RTC functionality goes, all models are the same. The855 * datasheets claim that different models have different number of856 * registers available for non-volatile storage, but experiments show857 * that all SoCs have 16 registers available for this purpose.858 */859static const struct of_device_id sun6i_rtc_dt_ids[] = {860	{ .compatible = "allwinner,sun6i-a31-rtc" },861	{ .compatible = "allwinner,sun8i-a23-rtc" },862	{ .compatible = "allwinner,sun8i-h3-rtc" },863	{ .compatible = "allwinner,sun8i-r40-rtc" },864	{ .compatible = "allwinner,sun8i-v3-rtc" },865	{ .compatible = "allwinner,sun50i-h5-rtc" },866	{ .compatible = "allwinner,sun50i-h6-rtc" },867	{ .compatible = "allwinner,sun50i-h616-rtc",868		.data = (void *)RTC_LINEAR_DAY },869	{ .compatible = "allwinner,sun50i-r329-rtc",870		.data = (void *)RTC_LINEAR_DAY },871	{ /* sentinel */ },872};873MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);874 875static struct platform_driver sun6i_rtc_driver = {876	.probe		= sun6i_rtc_probe,877	.driver		= {878		.name		= "sun6i-rtc",879		.of_match_table = sun6i_rtc_dt_ids,880		.pm = &sun6i_rtc_pm_ops,881	},882};883builtin_platform_driver(sun6i_rtc_driver);884