[deliverable/linux.git] / arch / x86 / platform / mrst / vrtc.c

/*
 * vrtc.c: Driver for virtual RTC device on Intel MID platform
 *
 * (C) Copyright 2009 Intel Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 *
 * Note:
 * VRTC is emulated by system controller firmware, the real HW
 * RTC is located in the PMIC device. SCU FW shadows PMIC RTC
 * in a memory mapped IO space that is visible to the host IA
 * processor.
 *
 * This driver is based on RTC CMOS driver.
 */

#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/sfi.h>
#include <linux/platform_device.h>

#include <asm/mrst.h>
#include <asm/mrst-vrtc.h>
#include <asm/time.h>
#include <asm/fixmap.h>

static unsigned char __iomem *vrtc_virt_base;

unsigned char vrtc_cmos_read(unsigned char reg)
{
	unsigned char retval;

	/* vRTC's registers range from 0x0 to 0xD */
	if (reg > 0xd || !vrtc_virt_base)
		return 0xff;

	lock_cmos_prefix(reg);
	retval = __raw_readb(vrtc_virt_base + (reg << 2));
	lock_cmos_suffix(reg);
	return retval;
}
EXPORT_SYMBOL_GPL(vrtc_cmos_read);

void vrtc_cmos_write(unsigned char val, unsigned char reg)
{
	if (reg > 0xd || !vrtc_virt_base)
		return;

	lock_cmos_prefix(reg);
	__raw_writeb(val, vrtc_virt_base + (reg << 2));
	lock_cmos_suffix(reg);
}
EXPORT_SYMBOL_GPL(vrtc_cmos_write);

unsigned long vrtc_get_time(void)
{
	u8 sec, min, hour, mday, mon;
	unsigned long flags;
	u32 year;

	spin_lock_irqsave(&rtc_lock, flags);

	while ((vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP))
		cpu_relax();

	sec = vrtc_cmos_read(RTC_SECONDS);
	min = vrtc_cmos_read(RTC_MINUTES);
	hour = vrtc_cmos_read(RTC_HOURS);
	mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
	mon = vrtc_cmos_read(RTC_MONTH);
	year = vrtc_cmos_read(RTC_YEAR);

	spin_unlock_irqrestore(&rtc_lock, flags);

	/* vRTC YEAR reg contains the offset to 1960 */
	year += 1960;

	printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d "
		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);

	return mktime(year, mon, mday, hour, min, sec);
}

/* Only care about the minutes and seconds */
int vrtc_set_mmss(unsigned long nowtime)
{
	int real_sec, real_min;
	unsigned long flags;
	int vrtc_min;

	spin_lock_irqsave(&rtc_lock, flags);
	vrtc_min = vrtc_cmos_read(RTC_MINUTES);

	real_sec = nowtime % 60;
	real_min = nowtime / 60;
	if (((abs(real_min - vrtc_min) + 15)/30) & 1)
		real_min += 30;
	real_min %= 60;

	vrtc_cmos_write(real_sec, RTC_SECONDS);
	vrtc_cmos_write(real_min, RTC_MINUTES);
	spin_unlock_irqrestore(&rtc_lock, flags);

	return 0;
}

void __init mrst_rtc_init(void)
{
	unsigned long vrtc_paddr;

	sfi_table_parse(SFI_SIG_MRTC, NULL, NULL, sfi_parse_mrtc);

	vrtc_paddr = sfi_mrtc_array[0].phys_addr;
	if (!sfi_mrtc_num || !vrtc_paddr)
		return;

	vrtc_virt_base = (void __iomem *)set_fixmap_offset_nocache(FIX_LNW_VRTC,
								vrtc_paddr);
	x86_platform.get_wallclock = vrtc_get_time;
	x86_platform.set_wallclock = vrtc_set_mmss;
}

/*
 * The Moorestown platform has a memory mapped virtual RTC device that emulates
 * the programming interface of the RTC.
 */

static struct resource vrtc_resources[] = {
	[0] = {
		.flags	= IORESOURCE_MEM,
	},
	[1] = {
		.flags	= IORESOURCE_IRQ,
	}
};

static struct platform_device vrtc_device = {
	.name		= "rtc_mrst",
	.id		= -1,
	.resource	= vrtc_resources,
	.num_resources	= ARRAY_SIZE(vrtc_resources),
};

/* Register the RTC device if appropriate */
static int __init mrst_device_create(void)
{
	/* No Moorestown, no device */
	if (!mrst_identify_cpu())
		return -ENODEV;
	/* No timer, no device */
	if (!sfi_mrtc_num)
		return -ENODEV;

	/* iomem resource */
	vrtc_resources[0].start = sfi_mrtc_array[0].phys_addr;
	vrtc_resources[0].end = sfi_mrtc_array[0].phys_addr +
				MRST_VRTC_MAP_SZ;
	/* irq resource */
	vrtc_resources[1].start = sfi_mrtc_array[0].irq;
	vrtc_resources[1].end = sfi_mrtc_array[0].irq;

	return platform_device_register(&vrtc_device);
}

module_init(mrst_device_create);
Commit	Line	Data
7309282c FT	1	/*
	2	* vrtc.c: Driver for virtual RTC device on Intel MID platform
	3	*
	4	* (C) Copyright 2009 Intel Corporation
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; version 2
	9	* of the License.
	10	*
	11	* Note:
	12	* VRTC is emulated by system controller firmware, the real HW
	13	* RTC is located in the PMIC device. SCU FW shadows PMIC RTC
	14	* in a memory mapped IO space that is visible to the host IA
	15	* processor.
	16	*
	17	* This driver is based on RTC CMOS driver.
	18	*/
	19
	20	#include <linux/kernel.h>
69c60c88	21	#include <linux/export.h>
7309282c FT	22	#include <linux/init.h>
7309282c FT	23	#include <linux/sfi.h>
0146f261	24	#include <linux/platform_device.h>
7309282c FT	25
	26	#include <asm/mrst.h>
	27	#include <asm/mrst-vrtc.h>
	28	#include <asm/time.h>
	29	#include <asm/fixmap.h>
	30
	31	static unsigned char __iomem *vrtc_virt_base;
	32
	33	unsigned char vrtc_cmos_read(unsigned char reg)
	34	{
	35	unsigned char retval;
	36
	37	/* vRTC's registers range from 0x0 to 0xD */
	38	if (reg > 0xd \|\| !vrtc_virt_base)
	39	return 0xff;
	40
	41	lock_cmos_prefix(reg);
	42	retval = __raw_readb(vrtc_virt_base + (reg << 2));
	43	lock_cmos_suffix(reg);
	44	return retval;
	45	}
	46	EXPORT_SYMBOL_GPL(vrtc_cmos_read);
	47
	48	void vrtc_cmos_write(unsigned char val, unsigned char reg)
	49	{
	50	if (reg > 0xd \|\| !vrtc_virt_base)
	51	return;
	52
	53	lock_cmos_prefix(reg);
	54	__raw_writeb(val, vrtc_virt_base + (reg << 2));
	55	lock_cmos_suffix(reg);
	56	}
	57	EXPORT_SYMBOL_GPL(vrtc_cmos_write);
	58
	59	unsigned long vrtc_get_time(void)
	60	{
	61	u8 sec, min, hour, mday, mon;
47997d75	62	unsigned long flags;
7309282c FT	63	u32 year;
7309282c FT	64
47997d75 MF	65	spin_lock_irqsave(&rtc_lock, flags);
47997d75 MF	66
7309282c FT	67	while ((vrtc_cmos_read(RTC_FREQ_SELECT) & RTC_UIP))
	68	cpu_relax();
	69
	70	sec = vrtc_cmos_read(RTC_SECONDS);
	71	min = vrtc_cmos_read(RTC_MINUTES);
	72	hour = vrtc_cmos_read(RTC_HOURS);
	73	mday = vrtc_cmos_read(RTC_DAY_OF_MONTH);
	74	mon = vrtc_cmos_read(RTC_MONTH);
	75	year = vrtc_cmos_read(RTC_YEAR);
	76
47997d75 MF	77	spin_unlock_irqrestore(&rtc_lock, flags);
47997d75 MF	78
7309282c FT	79	/* vRTC YEAR reg contains the offset to 1960 */
	80	year += 1960;
	81
	82	printk(KERN_INFO "vRTC: sec: %d min: %d hour: %d day: %d "
	83	"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
	84
	85	return mktime(year, mon, mday, hour, min, sec);
	86	}
	87
	88	/* Only care about the minutes and seconds */
	89	int vrtc_set_mmss(unsigned long nowtime)
	90	{
	91	int real_sec, real_min;
47997d75	92	unsigned long flags;
7309282c FT	93	int vrtc_min;
7309282c FT	94
47997d75	95	spin_lock_irqsave(&rtc_lock, flags);
7309282c FT	96	vrtc_min = vrtc_cmos_read(RTC_MINUTES);
	97
	98	real_sec = nowtime % 60;
	99	real_min = nowtime / 60;
	100	if (((abs(real_min - vrtc_min) + 15)/30) & 1)
	101	real_min += 30;
	102	real_min %= 60;
	103
	104	vrtc_cmos_write(real_sec, RTC_SECONDS);
	105	vrtc_cmos_write(real_min, RTC_MINUTES);
47997d75 MF	106	spin_unlock_irqrestore(&rtc_lock, flags);
47997d75 MF	107
7309282c FT	108	return 0;
	109	}
	110
	111	void __init mrst_rtc_init(void)
	112	{
09552b26	113	unsigned long vrtc_paddr;
7309282c FT	114
7309282c FT	115	sfi_table_parse(SFI_SIG_MRTC, NULL, NULL, sfi_parse_mrtc);
09552b26 FT	116
09552b26 FT	117	vrtc_paddr = sfi_mrtc_array[0].phys_addr;
168202c7	118	if (!sfi_mrtc_num \|\| !vrtc_paddr)
7309282c FT	119	return;
7309282c FT	120
168202c7 FT	121	vrtc_virt_base = (void __iomem *)set_fixmap_offset_nocache(FIX_LNW_VRTC,
168202c7 FT	122	vrtc_paddr);
7309282c FT	123	x86_platform.get_wallclock = vrtc_get_time;
	124	x86_platform.set_wallclock = vrtc_set_mmss;
	125	}
0146f261 FT	126
	127	/*
	128	* The Moorestown platform has a memory mapped virtual RTC device that emulates
	129	* the programming interface of the RTC.
	130	*/
	131
	132	static struct resource vrtc_resources[] = {
	133	[0] = {
	134	.flags = IORESOURCE_MEM,
	135	},
	136	[1] = {
	137	.flags = IORESOURCE_IRQ,
	138	}
	139	};
	140
	141	static struct platform_device vrtc_device = {
	142	.name = "rtc_mrst",
	143	.id = -1,
	144	.resource = vrtc_resources,
	145	.num_resources = ARRAY_SIZE(vrtc_resources),
	146	};
	147
	148	/* Register the RTC device if appropriate */
	149	static int __init mrst_device_create(void)
	150	{
	151	/* No Moorestown, no device */
	152	if (!mrst_identify_cpu())
	153	return -ENODEV;
	154	/* No timer, no device */
	155	if (!sfi_mrtc_num)
	156	return -ENODEV;
	157
	158	/* iomem resource */
	159	vrtc_resources[0].start = sfi_mrtc_array[0].phys_addr;
	160	vrtc_resources[0].end = sfi_mrtc_array[0].phys_addr +
	161	MRST_VRTC_MAP_SZ;
	162	/* irq resource */
	163	vrtc_resources[1].start = sfi_mrtc_array[0].irq;
	164	vrtc_resources[1].end = sfi_mrtc_array[0].irq;
	165
5ca9afdb	166	return platform_device_register(&vrtc_device);
0146f261 FT	167	}
	168
	169	module_init(mrst_device_create);