[linux-block.git] / drivers / rtc / rtc-zynqmp.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Xilinx Zynq Ultrascale+ MPSoC Real Time Clock Driver
 *
 * Copyright (C) 2015 Xilinx, Inc.
 *
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>

/* RTC Registers */
#define RTC_SET_TM_WR		0x00
#define RTC_SET_TM_RD		0x04
#define RTC_CALIB_WR		0x08
#define RTC_CALIB_RD		0x0C
#define RTC_CUR_TM		0x10
#define RTC_CUR_TICK		0x14
#define RTC_ALRM		0x18
#define RTC_INT_STS		0x20
#define RTC_INT_MASK		0x24
#define RTC_INT_EN		0x28
#define RTC_INT_DIS		0x2C
#define RTC_CTRL		0x40

#define RTC_FR_EN		BIT(20)
#define RTC_FR_DATSHIFT		16
#define RTC_TICK_MASK		0xFFFF
#define RTC_INT_SEC		BIT(0)
#define RTC_INT_ALRM		BIT(1)
#define RTC_OSC_EN		BIT(24)
#define RTC_BATT_EN		BIT(31)

#define RTC_CALIB_DEF		0x7FFF
#define RTC_CALIB_MASK		0x1FFFFF
#define RTC_ALRM_MASK          BIT(1)
#define RTC_MSEC               1000
#define RTC_FR_MASK		0xF0000
#define RTC_FR_MAX_TICKS	16
#define RTC_PPB			1000000000LL
#define RTC_MIN_OFFSET		-32768000
#define RTC_MAX_OFFSET		32767000

struct xlnx_rtc_dev {
	struct rtc_device	*rtc;
	void __iomem		*reg_base;
	int			alarm_irq;
	int			sec_irq;
	struct clk		*rtc_clk;
	unsigned int		freq;
};

static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	unsigned long new_time;

	/*
	 * The value written will be updated after 1 sec into the
	 * seconds read register, so we need to program time +1 sec
	 * to get the correct time on read.
	 */
	new_time = rtc_tm_to_time64(tm) + 1;

	writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR);

	/*
	 * Clear the rtc interrupt status register after setting the
	 * time. During a read_time function, the code should read the
	 * RTC_INT_STATUS register and if bit 0 is still 0, it means
	 * that one second has not elapsed yet since RTC was set and
	 * the current time should be read from SET_TIME_READ register;
	 * otherwise, CURRENT_TIME register is read to report the time
	 */
	writel(RTC_INT_SEC, xrtcdev->reg_base + RTC_INT_STS);

	return 0;
}

static int xlnx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	u32 status;
	unsigned long read_time;
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);

	status = readl(xrtcdev->reg_base + RTC_INT_STS);

	if (status & RTC_INT_SEC) {
		/*
		 * RTC has updated the CURRENT_TIME with the time written into
		 * SET_TIME_WRITE register.
		 */
		read_time = readl(xrtcdev->reg_base + RTC_CUR_TM);
	} else {
		/*
		 * Time written in SET_TIME_WRITE has not yet updated into
		 * the seconds read register, so read the time from the
		 * SET_TIME_WRITE instead of CURRENT_TIME register.
		 * Since we add +1 sec while writing, we need to -1 sec while
		 * reading.
		 */
		read_time = readl(xrtcdev->reg_base + RTC_SET_TM_RD) - 1;
	}
	rtc_time64_to_tm(read_time, tm);

	return 0;
}

static int xlnx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);

	rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_ALRM), &alrm->time);
	alrm->enabled = readl(xrtcdev->reg_base + RTC_INT_MASK) & RTC_INT_ALRM;

	return 0;
}

static int xlnx_rtc_alarm_irq_enable(struct device *dev, u32 enabled)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	unsigned int status;
	ulong timeout;

	timeout = jiffies + msecs_to_jiffies(RTC_MSEC);

	if (enabled) {
		while (1) {
			status = readl(xrtcdev->reg_base + RTC_INT_STS);
			if (!((status & RTC_ALRM_MASK) == RTC_ALRM_MASK))
				break;

			if (time_after_eq(jiffies, timeout)) {
				dev_err(dev, "Time out occur, while clearing alarm status bit\n");
				return -ETIMEDOUT;
			}
			writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_STS);
		}

		writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_EN);
	} else {
		writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
	}

	return 0;
}

static int xlnx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	unsigned long alarm_time;

	alarm_time = rtc_tm_to_time64(&alrm->time);

	writel((u32)alarm_time, (xrtcdev->reg_base + RTC_ALRM));

	xlnx_rtc_alarm_irq_enable(dev, alrm->enabled);

	return 0;
}

static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev)
{
	u32 rtc_ctrl;

	/* Enable RTC switch to battery when VCC_PSAUX is not available */
	rtc_ctrl = readl(xrtcdev->reg_base + RTC_CTRL);
	rtc_ctrl |= RTC_BATT_EN;
	writel(rtc_ctrl, xrtcdev->reg_base + RTC_CTRL);
}

static int xlnx_rtc_read_offset(struct device *dev, long *offset)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	unsigned long long rtc_ppb = RTC_PPB;
	unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq);
	unsigned int calibval;
	long offset_val;

	calibval = readl(xrtcdev->reg_base + RTC_CALIB_RD);
	/* Offset with seconds ticks */
	offset_val = calibval & RTC_TICK_MASK;
	offset_val = offset_val - RTC_CALIB_DEF;
	offset_val = offset_val * tick_mult;

	/* Offset with fractional ticks */
	if (calibval & RTC_FR_EN)
		offset_val += ((calibval & RTC_FR_MASK) >> RTC_FR_DATSHIFT)
			* (tick_mult / RTC_FR_MAX_TICKS);
	*offset = offset_val;

	return 0;
}

static int xlnx_rtc_set_offset(struct device *dev, long offset)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	unsigned long long rtc_ppb = RTC_PPB;
	unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq);
	unsigned char fract_tick = 0;
	unsigned int calibval;
	short int  max_tick;
	int fract_offset;

	if (offset < RTC_MIN_OFFSET || offset > RTC_MAX_OFFSET)
		return -ERANGE;

	/* Number ticks for given offset */
	max_tick = div_s64_rem(offset, tick_mult, &fract_offset);

	/* Number fractional ticks for given offset */
	if (fract_offset) {
		if (fract_offset < 0) {
			fract_offset = fract_offset + tick_mult;
			max_tick--;
		}
		if (fract_offset > (tick_mult / RTC_FR_MAX_TICKS)) {
			for (fract_tick = 1; fract_tick < 16; fract_tick++) {
				if (fract_offset <=
				    (fract_tick *
				     (tick_mult / RTC_FR_MAX_TICKS)))
					break;
			}
		}
	}

	/* Zynqmp RTC uses second and fractional tick
	 * counters for compensation
	 */
	calibval = max_tick + RTC_CALIB_DEF;

	if (fract_tick)
		calibval |= RTC_FR_EN;

	calibval |= (fract_tick << RTC_FR_DATSHIFT);

	writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR));

	return 0;
}

static const struct rtc_class_ops xlnx_rtc_ops = {
	.set_time	  = xlnx_rtc_set_time,
	.read_time	  = xlnx_rtc_read_time,
	.read_alarm	  = xlnx_rtc_read_alarm,
	.set_alarm	  = xlnx_rtc_set_alarm,
	.alarm_irq_enable = xlnx_rtc_alarm_irq_enable,
	.read_offset	  = xlnx_rtc_read_offset,
	.set_offset	  = xlnx_rtc_set_offset,
};

static irqreturn_t xlnx_rtc_interrupt(int irq, void *id)
{
	struct xlnx_rtc_dev *xrtcdev = (struct xlnx_rtc_dev *)id;
	unsigned int status;

	status = readl(xrtcdev->reg_base + RTC_INT_STS);
	/* Check if interrupt asserted */
	if (!(status & (RTC_INT_SEC | RTC_INT_ALRM)))
		return IRQ_NONE;

	/* Disable RTC_INT_ALRM interrupt only */
	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);

	if (status & RTC_INT_ALRM)
		rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;
}

static int xlnx_rtc_probe(struct platform_device *pdev)
{
	struct xlnx_rtc_dev *xrtcdev;
	int ret;

	xrtcdev = devm_kzalloc(&pdev->dev, sizeof(*xrtcdev), GFP_KERNEL);
	if (!xrtcdev)
		return -ENOMEM;

	platform_set_drvdata(pdev, xrtcdev);

	xrtcdev->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(xrtcdev->rtc))
		return PTR_ERR(xrtcdev->rtc);

	xrtcdev->rtc->ops = &xlnx_rtc_ops;
	xrtcdev->rtc->range_max = U32_MAX;

	xrtcdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(xrtcdev->reg_base))
		return PTR_ERR(xrtcdev->reg_base);

	xrtcdev->alarm_irq = platform_get_irq_byname(pdev, "alarm");
	if (xrtcdev->alarm_irq < 0)
		return xrtcdev->alarm_irq;
	ret = devm_request_irq(&pdev->dev, xrtcdev->alarm_irq,
			       xlnx_rtc_interrupt, 0,
			       dev_name(&pdev->dev), xrtcdev);
	if (ret) {
		dev_err(&pdev->dev, "request irq failed\n");
		return ret;
	}

	xrtcdev->sec_irq = platform_get_irq_byname(pdev, "sec");
	if (xrtcdev->sec_irq < 0)
		return xrtcdev->sec_irq;
	ret = devm_request_irq(&pdev->dev, xrtcdev->sec_irq,
			       xlnx_rtc_interrupt, 0,
			       dev_name(&pdev->dev), xrtcdev);
	if (ret) {
		dev_err(&pdev->dev, "request irq failed\n");
		return ret;
	}

	/* Getting the rtc_clk info */
	xrtcdev->rtc_clk = devm_clk_get_optional(&pdev->dev, "rtc_clk");
	if (IS_ERR(xrtcdev->rtc_clk)) {
		if (PTR_ERR(xrtcdev->rtc_clk) != -EPROBE_DEFER)
			dev_warn(&pdev->dev, "Device clock not found.\n");
	}
	xrtcdev->freq = clk_get_rate(xrtcdev->rtc_clk);
	if (!xrtcdev->freq) {
		ret = of_property_read_u32(pdev->dev.of_node, "calibration",
					   &xrtcdev->freq);
		if (ret)
			xrtcdev->freq = RTC_CALIB_DEF;
	}
	ret = readl(xrtcdev->reg_base + RTC_CALIB_RD);
	if (!ret)
		writel(xrtcdev->freq, (xrtcdev->reg_base + RTC_CALIB_WR));

	xlnx_init_rtc(xrtcdev);

	device_init_wakeup(&pdev->dev, 1);

	return devm_rtc_register_device(xrtcdev->rtc);
}

static int xlnx_rtc_remove(struct platform_device *pdev)
{
	xlnx_rtc_alarm_irq_enable(&pdev->dev, 0);
	device_init_wakeup(&pdev->dev, 0);

	return 0;
}

static int __maybe_unused xlnx_rtc_suspend(struct device *dev)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(xrtcdev->alarm_irq);
	else
		xlnx_rtc_alarm_irq_enable(dev, 0);

	return 0;
}

static int __maybe_unused xlnx_rtc_resume(struct device *dev)
{
	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(xrtcdev->alarm_irq);
	else
		xlnx_rtc_alarm_irq_enable(dev, 1);

	return 0;
}

static SIMPLE_DEV_PM_OPS(xlnx_rtc_pm_ops, xlnx_rtc_suspend, xlnx_rtc_resume);

static const struct of_device_id xlnx_rtc_of_match[] = {
	{.compatible = "xlnx,zynqmp-rtc" },
	{ }
};
MODULE_DEVICE_TABLE(of, xlnx_rtc_of_match);

static struct platform_driver xlnx_rtc_driver = {
	.probe		= xlnx_rtc_probe,
	.remove		= xlnx_rtc_remove,
	.driver		= {
		.name	= KBUILD_MODNAME,
		.pm	= &xlnx_rtc_pm_ops,
		.of_match_table	= xlnx_rtc_of_match,
	},
};

module_platform_driver(xlnx_rtc_driver);

MODULE_DESCRIPTION("Xilinx Zynq MPSoC RTC driver");
MODULE_AUTHOR("Xilinx Inc.");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
28e7861c	1	// SPDX-License-Identifier: GPL-2.0
11143c19 SG	2	/*
	3	* Xilinx Zynq Ultrascale+ MPSoC Real Time Clock Driver
	4	*
	5	* Copyright (C) 2015 Xilinx, Inc.
	6	*
11143c19 SG	7	*/
11143c19 SG	8
07dcc6f9	9	#include <linux/clk.h>
11143c19 SG	10	#include <linux/delay.h>
	11	#include <linux/init.h>
	12	#include <linux/io.h>
	13	#include <linux/module.h>
	14	#include <linux/of.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/rtc.h>
	17
	18	/* RTC Registers */
	19	#define RTC_SET_TM_WR 0x00
	20	#define RTC_SET_TM_RD 0x04
	21	#define RTC_CALIB_WR 0x08
	22	#define RTC_CALIB_RD 0x0C
	23	#define RTC_CUR_TM 0x10
	24	#define RTC_CUR_TICK 0x14
	25	#define RTC_ALRM 0x18
	26	#define RTC_INT_STS 0x20
	27	#define RTC_INT_MASK 0x24
	28	#define RTC_INT_EN 0x28
	29	#define RTC_INT_DIS 0x2C
	30	#define RTC_CTRL 0x40
	31
	32	#define RTC_FR_EN BIT(20)
	33	#define RTC_FR_DATSHIFT 16
	34	#define RTC_TICK_MASK 0xFFFF
	35	#define RTC_INT_SEC BIT(0)
	36	#define RTC_INT_ALRM BIT(1)
	37	#define RTC_OSC_EN BIT(24)
9092984f	38	#define RTC_BATT_EN BIT(31)
11143c19	39
85cab027	40	#define RTC_CALIB_DEF 0x7FFF
11143c19	41	#define RTC_CALIB_MASK 0x1FFFFF
4594d082 SN	42	#define RTC_ALRM_MASK BIT(1)
4594d082 SN	43	#define RTC_MSEC 1000
07dcc6f9 SN	44	#define RTC_FR_MASK 0xF0000
	45	#define RTC_FR_MAX_TICKS 16
	46	#define RTC_PPB 1000000000LL
	47	#define RTC_MIN_OFFSET -32768000
	48	#define RTC_MAX_OFFSET 32767000
11143c19 SG	49
	50	struct xlnx_rtc_dev {
	51	struct rtc_device *rtc;
	52	void __iomem *reg_base;
	53	int alarm_irq;
	54	int sec_irq;
07dcc6f9 SN	55	struct clk *rtc_clk;
07dcc6f9 SN	56	unsigned int freq;
11143c19 SG	57	};
	58
	59	static int xlnx_rtc_set_time(struct device dev, struct rtc_time tm)
	60	{
	61	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	62	unsigned long new_time;
	63
b62c3a11 AKV	64	/*
	65	* The value written will be updated after 1 sec into the
	66	* seconds read register, so we need to program time +1 sec
	67	* to get the correct time on read.
	68	*/
	69	new_time = rtc_tm_to_time64(tm) + 1;
11143c19	70
11143c19 SG	71	writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR);
11143c19 SG	72
b62c3a11 AKV	73	/*
	74	* Clear the rtc interrupt status register after setting the
	75	* time. During a read_time function, the code should read the
	76	* RTC_INT_STATUS register and if bit 0 is still 0, it means
	77	* that one second has not elapsed yet since RTC was set and
	78	* the current time should be read from SET_TIME_READ register;
	79	* otherwise, CURRENT_TIME register is read to report the time
	80	*/
	81	writel(RTC_INT_SEC, xrtcdev->reg_base + RTC_INT_STS);
	82
11143c19 SG	83	return 0;
	84	}
	85
	86	static int xlnx_rtc_read_time(struct device dev, struct rtc_time tm)
	87	{
b62c3a11 AKV	88	u32 status;
b62c3a11 AKV	89	unsigned long read_time;
11143c19 SG	90	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
11143c19 SG	91
b62c3a11 AKV	92	status = readl(xrtcdev->reg_base + RTC_INT_STS);
	93
	94	if (status & RTC_INT_SEC) {
	95	/*
	96	* RTC has updated the CURRENT_TIME with the time written into
	97	* SET_TIME_WRITE register.
	98	*/
519d6370	99	read_time = readl(xrtcdev->reg_base + RTC_CUR_TM);
b62c3a11 AKV	100	} else {
	101	/*
	102	* Time written in SET_TIME_WRITE has not yet updated into
	103	* the seconds read register, so read the time from the
	104	* SET_TIME_WRITE instead of CURRENT_TIME register.
	105	* Since we add +1 sec while writing, we need to -1 sec while
	106	* reading.
	107	*/
	108	read_time = readl(xrtcdev->reg_base + RTC_SET_TM_RD) - 1;
b62c3a11	109	}
519d6370	110	rtc_time64_to_tm(read_time, tm);
11143c19	111
146d21bd	112	return 0;
11143c19 SG	113	}
	114
	115	static int xlnx_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	116	{
	117	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	118
	119	rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_ALRM), &alrm->time);
	120	alrm->enabled = readl(xrtcdev->reg_base + RTC_INT_MASK) & RTC_INT_ALRM;
	121
	122	return 0;
	123	}
	124
	125	static int xlnx_rtc_alarm_irq_enable(struct device *dev, u32 enabled)
	126	{
	127	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
4594d082 SN	128	unsigned int status;
	129	ulong timeout;
	130
	131	timeout = jiffies + msecs_to_jiffies(RTC_MSEC);
	132
	133	if (enabled) {
	134	while (1) {
	135	status = readl(xrtcdev->reg_base + RTC_INT_STS);
	136	if (!((status & RTC_ALRM_MASK) == RTC_ALRM_MASK))
	137	break;
	138
	139	if (time_after_eq(jiffies, timeout)) {
	140	dev_err(dev, "Time out occur, while clearing alarm status bit\n");
	141	return -ETIMEDOUT;
	142	}
	143	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_STS);
	144	}
11143c19	145
11143c19	146	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_EN);
4594d082	147	} else {
11143c19	148	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
4594d082	149	}
11143c19 SG	150
	151	return 0;
	152	}
	153
	154	static int xlnx_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	155	{
	156	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	157	unsigned long alarm_time;
	158
	159	alarm_time = rtc_tm_to_time64(&alrm->time);
	160
11143c19 SG	161	writel((u32)alarm_time, (xrtcdev->reg_base + RTC_ALRM));
	162
	163	xlnx_rtc_alarm_irq_enable(dev, alrm->enabled);
	164
	165	return 0;
	166	}
	167
58c4ed3b	168	static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev)
11143c19	169	{
9092984f AKV	170	u32 rtc_ctrl;
	171
	172	/* Enable RTC switch to battery when VCC_PSAUX is not available */
	173	rtc_ctrl = readl(xrtcdev->reg_base + RTC_CTRL);
	174	rtc_ctrl \|= RTC_BATT_EN;
	175	writel(rtc_ctrl, xrtcdev->reg_base + RTC_CTRL);
07dcc6f9	176	}
9092984f	177
07dcc6f9 SN	178	static int xlnx_rtc_read_offset(struct device dev, long offset)
	179	{
	180	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	181	unsigned long long rtc_ppb = RTC_PPB;
	182	unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq);
	183	unsigned int calibval;
	184	long offset_val;
	185
	186	calibval = readl(xrtcdev->reg_base + RTC_CALIB_RD);
	187	/* Offset with seconds ticks */
	188	offset_val = calibval & RTC_TICK_MASK;
	189	offset_val = offset_val - RTC_CALIB_DEF;
	190	offset_val = offset_val * tick_mult;
	191
	192	/* Offset with fractional ticks */
	193	if (calibval & RTC_FR_EN)
	194	offset_val += ((calibval & RTC_FR_MASK) >> RTC_FR_DATSHIFT)
	195	* (tick_mult / RTC_FR_MAX_TICKS);
	196	*offset = offset_val;
	197
	198	return 0;
	199	}
	200
	201	static int xlnx_rtc_set_offset(struct device *dev, long offset)
	202	{
	203	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
	204	unsigned long long rtc_ppb = RTC_PPB;
	205	unsigned int tick_mult = do_div(rtc_ppb, xrtcdev->freq);
c9a1dd67	206	unsigned char fract_tick = 0;
07dcc6f9 SN	207	unsigned int calibval;
	208	short int max_tick;
	209	int fract_offset;
	210
	211	if (offset < RTC_MIN_OFFSET \|\| offset > RTC_MAX_OFFSET)
	212	return -ERANGE;
	213
	214	/* Number ticks for given offset */
	215	max_tick = div_s64_rem(offset, tick_mult, &fract_offset);
	216
	217	/* Number fractional ticks for given offset */
	218	if (fract_offset) {
	219	if (fract_offset < 0) {
	220	fract_offset = fract_offset + tick_mult;
	221	max_tick--;
	222	}
	223	if (fract_offset > (tick_mult / RTC_FR_MAX_TICKS)) {
	224	for (fract_tick = 1; fract_tick < 16; fract_tick++) {
	225	if (fract_offset <=
	226	(fract_tick *
	227	(tick_mult / RTC_FR_MAX_TICKS)))
	228	break;
	229	}
	230	}
	231	}
	232
	233	/* Zynqmp RTC uses second and fractional tick
	234	* counters for compensation
11143c19	235	*/
07dcc6f9 SN	236	calibval = max_tick + RTC_CALIB_DEF;
	237
	238	if (fract_tick)
	239	calibval \|= RTC_FR_EN;
	240
	241	calibval \|= (fract_tick << RTC_FR_DATSHIFT);
	242
	243	writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR));
	244
	245	return 0;
11143c19 SG	246	}
	247
	248	static const struct rtc_class_ops xlnx_rtc_ops = {
	249	.set_time = xlnx_rtc_set_time,
	250	.read_time = xlnx_rtc_read_time,
	251	.read_alarm = xlnx_rtc_read_alarm,
	252	.set_alarm = xlnx_rtc_set_alarm,
	253	.alarm_irq_enable = xlnx_rtc_alarm_irq_enable,
07dcc6f9 SN	254	.read_offset = xlnx_rtc_read_offset,
07dcc6f9 SN	255	.set_offset = xlnx_rtc_set_offset,
11143c19 SG	256	};
	257
	258	static irqreturn_t xlnx_rtc_interrupt(int irq, void *id)
	259	{
	260	struct xlnx_rtc_dev xrtcdev = (struct xlnx_rtc_dev )id;
	261	unsigned int status;
	262
	263	status = readl(xrtcdev->reg_base + RTC_INT_STS);
	264	/* Check if interrupt asserted */
	265	if (!(status & (RTC_INT_SEC \| RTC_INT_ALRM)))
	266	return IRQ_NONE;
	267
4594d082 SN	268	/* Disable RTC_INT_ALRM interrupt only */
4594d082 SN	269	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
11143c19	270
11143c19 SG	271	if (status & RTC_INT_ALRM)
	272	rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF \| RTC_AF);
	273
	274	return IRQ_HANDLED;
	275	}
	276
	277	static int xlnx_rtc_probe(struct platform_device *pdev)
	278	{
	279	struct xlnx_rtc_dev *xrtcdev;
11143c19	280	int ret;
11143c19 SG	281
	282	xrtcdev = devm_kzalloc(&pdev->dev, sizeof(*xrtcdev), GFP_KERNEL);
	283	if (!xrtcdev)
	284	return -ENOMEM;
	285
	286	platform_set_drvdata(pdev, xrtcdev);
	287
b8541798 AB	288	xrtcdev->rtc = devm_rtc_allocate_device(&pdev->dev);
	289	if (IS_ERR(xrtcdev->rtc))
	290	return PTR_ERR(xrtcdev->rtc);
	291
	292	xrtcdev->rtc->ops = &xlnx_rtc_ops;
3199fc3d	293	xrtcdev->rtc->range_max = U32_MAX;
b8541798	294
09ef18bc	295	xrtcdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
11143c19 SG	296	if (IS_ERR(xrtcdev->reg_base))
	297	return PTR_ERR(xrtcdev->reg_base);
	298
	299	xrtcdev->alarm_irq = platform_get_irq_byname(pdev, "alarm");
faac9102	300	if (xrtcdev->alarm_irq < 0)
11143c19	301	return xrtcdev->alarm_irq;
11143c19 SG	302	ret = devm_request_irq(&pdev->dev, xrtcdev->alarm_irq,
	303	xlnx_rtc_interrupt, 0,
	304	dev_name(&pdev->dev), xrtcdev);
	305	if (ret) {
	306	dev_err(&pdev->dev, "request irq failed\n");
	307	return ret;
	308	}
	309
	310	xrtcdev->sec_irq = platform_get_irq_byname(pdev, "sec");
faac9102	311	if (xrtcdev->sec_irq < 0)
11143c19	312	return xrtcdev->sec_irq;
11143c19 SG	313	ret = devm_request_irq(&pdev->dev, xrtcdev->sec_irq,
	314	xlnx_rtc_interrupt, 0,
	315	dev_name(&pdev->dev), xrtcdev);
	316	if (ret) {
	317	dev_err(&pdev->dev, "request irq failed\n");
	318	return ret;
	319	}
	320
07dcc6f9 SN	321	/* Getting the rtc_clk info */
	322	xrtcdev->rtc_clk = devm_clk_get_optional(&pdev->dev, "rtc_clk");
	323	if (IS_ERR(xrtcdev->rtc_clk)) {
	324	if (PTR_ERR(xrtcdev->rtc_clk) != -EPROBE_DEFER)
	325	dev_warn(&pdev->dev, "Device clock not found.\n");
	326	}
	327	xrtcdev->freq = clk_get_rate(xrtcdev->rtc_clk);
	328	if (!xrtcdev->freq) {
	329	ret = of_property_read_u32(pdev->dev.of_node, "calibration",
	330	&xrtcdev->freq);
	331	if (ret)
	332	xrtcdev->freq = RTC_CALIB_DEF;
	333	}
	334	ret = readl(xrtcdev->reg_base + RTC_CALIB_RD);
	335	if (!ret)
	336	writel(xrtcdev->freq, (xrtcdev->reg_base + RTC_CALIB_WR));
11143c19	337
58c4ed3b	338	xlnx_init_rtc(xrtcdev);
11143c19 SG	339
	340	device_init_wakeup(&pdev->dev, 1);
	341
fdcfd854	342	return devm_rtc_register_device(xrtcdev->rtc);
11143c19 SG	343	}
	344
	345	static int xlnx_rtc_remove(struct platform_device *pdev)
	346	{
	347	xlnx_rtc_alarm_irq_enable(&pdev->dev, 0);
	348	device_init_wakeup(&pdev->dev, 0);
	349
	350	return 0;
	351	}
	352
	353	static int __maybe_unused xlnx_rtc_suspend(struct device *dev)
	354	{
85368bb9	355	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
11143c19	356
85368bb9	357	if (device_may_wakeup(dev))
11143c19 SG	358	enable_irq_wake(xrtcdev->alarm_irq);
	359	else
	360	xlnx_rtc_alarm_irq_enable(dev, 0);
	361
	362	return 0;
	363	}
	364
	365	static int __maybe_unused xlnx_rtc_resume(struct device *dev)
	366	{
85368bb9	367	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
11143c19	368
85368bb9	369	if (device_may_wakeup(dev))
11143c19 SG	370	disable_irq_wake(xrtcdev->alarm_irq);
	371	else
	372	xlnx_rtc_alarm_irq_enable(dev, 1);
	373
	374	return 0;
	375	}
	376
	377	static SIMPLE_DEV_PM_OPS(xlnx_rtc_pm_ops, xlnx_rtc_suspend, xlnx_rtc_resume);
	378
	379	static const struct of_device_id xlnx_rtc_of_match[] = {
	380	{.compatible = "xlnx,zynqmp-rtc" },
	381	{ }
	382	};
	383	MODULE_DEVICE_TABLE(of, xlnx_rtc_of_match);
	384
	385	static struct platform_driver xlnx_rtc_driver = {
	386	.probe = xlnx_rtc_probe,
	387	.remove = xlnx_rtc_remove,
	388	.driver = {
	389	.name = KBUILD_MODNAME,
	390	.pm = &xlnx_rtc_pm_ops,
	391	.of_match_table = xlnx_rtc_of_match,
	392	},
	393	};
	394
	395	module_platform_driver(xlnx_rtc_driver);
	396
	397	MODULE_DESCRIPTION("Xilinx Zynq MPSoC RTC driver");
	398	MODULE_AUTHOR("Xilinx Inc.");
	399	MODULE_LICENSE("GPL v2");