rtc-pl030.c 3.86 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
/*
 *  linux/drivers/rtc/rtc-pl030.c
 *
 *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/amba/bus.h>
#include <linux/io.h>
16
#include <linux/slab.h>
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

#define RTC_DR		(0)
#define RTC_MR		(4)
#define RTC_STAT	(8)
#define RTC_EOI		(8)
#define RTC_LR		(12)
#define RTC_CR		(16)
#define RTC_CR_MIE	(1 << 0)

struct pl030_rtc {
	struct rtc_device	*rtc;
	void __iomem		*base;
};

static irqreturn_t pl030_interrupt(int irq, void *dev_id)
{
	struct pl030_rtc *rtc = dev_id;
	writel(0, rtc->base + RTC_EOI);
	return IRQ_HANDLED;
}

static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct pl030_rtc *rtc = dev_get_drvdata(dev);

	rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
	return 0;
}

static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct pl030_rtc *rtc = dev_get_drvdata(dev);
	unsigned long time;
	int ret;

	/*
	 * At the moment, we can only deal with non-wildcarded alarm times.
	 */
	ret = rtc_valid_tm(&alrm->time);
	if (ret == 0)
		ret = rtc_tm_to_time(&alrm->time, &time);
	if (ret == 0)
		writel(time, rtc->base + RTC_MR);
	return ret;
}

static int pl030_read_time(struct device *dev, struct rtc_time *tm)
{
	struct pl030_rtc *rtc = dev_get_drvdata(dev);

	rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);

	return 0;
}

/*
 * Set the RTC time.  Unfortunately, we can't accurately set
 * the point at which the counter updates.
 *
 * Also, since RTC_LR is transferred to RTC_CR on next rising
 * edge of the 1Hz clock, we must write the time one second
 * in advance.
 */
static int pl030_set_time(struct device *dev, struct rtc_time *tm)
{
	struct pl030_rtc *rtc = dev_get_drvdata(dev);
	unsigned long time;
	int ret;

	ret = rtc_tm_to_time(tm, &time);
	if (ret == 0)
		writel(time + 1, rtc->base + RTC_LR);

	return ret;
}

static const struct rtc_class_ops pl030_ops = {
	.read_time	= pl030_read_time,
	.set_time	= pl030_set_time,
	.read_alarm	= pl030_read_alarm,
	.set_alarm	= pl030_set_alarm,
};

100
static int pl030_probe(struct amba_device *dev, const struct amba_id *id)
101 102 103 104 105 106 107 108
{
	struct pl030_rtc *rtc;
	int ret;

	ret = amba_request_regions(dev, NULL);
	if (ret)
		goto err_req;

109
	rtc = devm_kzalloc(&dev->dev, sizeof(*rtc), GFP_KERNEL);
110 111 112 113 114
	if (!rtc) {
		ret = -ENOMEM;
		goto err_rtc;
	}

115 116 117 118 119 120 121
	rtc->rtc = devm_rtc_allocate_device(&dev->dev);
	if (IS_ERR(rtc->rtc)) {
		ret = PTR_ERR(rtc->rtc);
		goto err_rtc;
	}

	rtc->rtc->ops = &pl030_ops;
122
	rtc->base = ioremap(dev->res.start, resource_size(&dev->res));
123 124
	if (!rtc->base) {
		ret = -ENOMEM;
125
		goto err_rtc;
126 127 128 129 130 131 132
	}

	__raw_writel(0, rtc->base + RTC_CR);
	__raw_writel(0, rtc->base + RTC_EOI);

	amba_set_drvdata(dev, rtc);

133
	ret = request_irq(dev->irq[0], pl030_interrupt, 0,
134 135 136 137
			  "rtc-pl030", rtc);
	if (ret)
		goto err_irq;

138 139
	ret = rtc_register_device(rtc->rtc);
	if (ret)
140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174
		goto err_reg;

	return 0;

 err_reg:
	free_irq(dev->irq[0], rtc);
 err_irq:
	iounmap(rtc->base);
 err_rtc:
	amba_release_regions(dev);
 err_req:
	return ret;
}

static int pl030_remove(struct amba_device *dev)
{
	struct pl030_rtc *rtc = amba_get_drvdata(dev);

	writel(0, rtc->base + RTC_CR);

	free_irq(dev->irq[0], rtc);
	iounmap(rtc->base);
	amba_release_regions(dev);

	return 0;
}

static struct amba_id pl030_ids[] = {
	{
		.id	= 0x00041030,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};

175 176
MODULE_DEVICE_TABLE(amba, pl030_ids);

177 178 179 180 181 182 183 184 185
static struct amba_driver pl030_driver = {
	.drv		= {
		.name	= "rtc-pl030",
	},
	.probe		= pl030_probe,
	.remove		= pl030_remove,
	.id_table	= pl030_ids,
};

186
module_amba_driver(pl030_driver);
187 188 189 190

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
MODULE_LICENSE("GPL");