cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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rtc-max77686.c (23172B)


      1// SPDX-License-Identifier: GPL-2.0+
      2//
      3// RTC driver for Maxim MAX77686 and MAX77802
      4//
      5// Copyright (C) 2012 Samsung Electronics Co.Ltd
      6//
      7//  based on rtc-max8997.c
      8
      9#include <linux/i2c.h>
     10#include <linux/slab.h>
     11#include <linux/rtc.h>
     12#include <linux/delay.h>
     13#include <linux/mutex.h>
     14#include <linux/module.h>
     15#include <linux/platform_device.h>
     16#include <linux/mfd/max77686-private.h>
     17#include <linux/irqdomain.h>
     18#include <linux/regmap.h>
     19
     20#define MAX77686_I2C_ADDR_RTC		(0x0C >> 1)
     21#define MAX77620_I2C_ADDR_RTC		0x68
     22#define MAX77714_I2C_ADDR_RTC		0x48
     23#define MAX77686_INVALID_I2C_ADDR	(-1)
     24
     25/* Define non existing register */
     26#define MAX77686_INVALID_REG		(-1)
     27
     28/* RTC Control Register */
     29#define BCD_EN_SHIFT			0
     30#define BCD_EN_MASK			BIT(BCD_EN_SHIFT)
     31#define MODEL24_SHIFT			1
     32#define MODEL24_MASK			BIT(MODEL24_SHIFT)
     33/* RTC Update Register1 */
     34#define RTC_UDR_SHIFT			0
     35#define RTC_UDR_MASK			BIT(RTC_UDR_SHIFT)
     36#define RTC_RBUDR_SHIFT			4
     37#define RTC_RBUDR_MASK			BIT(RTC_RBUDR_SHIFT)
     38/* RTC Alarm Enable */
     39#define ALARM_ENABLE_SHIFT		7
     40#define ALARM_ENABLE_MASK		BIT(ALARM_ENABLE_SHIFT)
     41
     42#define REG_RTC_NONE			0xdeadbeef
     43
     44/*
     45 * MAX77802 has separate register (RTCAE1) for alarm enable instead
     46 * using 1 bit from registers RTC{SEC,MIN,HOUR,DAY,MONTH,YEAR,DATE}
     47 * as in done in MAX77686.
     48 */
     49#define MAX77802_ALARM_ENABLE_VALUE	0x77
     50
     51enum {
     52	RTC_SEC = 0,
     53	RTC_MIN,
     54	RTC_HOUR,
     55	RTC_WEEKDAY,
     56	RTC_MONTH,
     57	RTC_YEAR,
     58	RTC_MONTHDAY,
     59	RTC_NR_TIME
     60};
     61
     62/**
     63 * struct max77686_rtc_driver_data - model-specific configuration
     64 * @delay: Minimum usecs needed for a RTC update
     65 * @mask: Mask used to read RTC registers value
     66 * @map: Registers offset to I2C addresses map
     67 * @alarm_enable_reg: Has a separate alarm enable register?
     68 * @rtc_i2c_addr: I2C address for RTC block
     69 * @rtc_irq_from_platform: RTC interrupt via platform resource
     70 * @alarm_pending_status_reg: Pending alarm status register
     71 * @rtc_irq_chip: RTC IRQ CHIP for regmap
     72 * @regmap_config: regmap configuration for the chip
     73 */
     74struct max77686_rtc_driver_data {
     75	unsigned long		delay;
     76	u8			mask;
     77	const unsigned int	*map;
     78	bool			alarm_enable_reg;
     79	int			rtc_i2c_addr;
     80	bool			rtc_irq_from_platform;
     81	int			alarm_pending_status_reg;
     82	const struct regmap_irq_chip *rtc_irq_chip;
     83	const struct regmap_config *regmap_config;
     84};
     85
     86struct max77686_rtc_info {
     87	struct device		*dev;
     88	struct i2c_client	*rtc;
     89	struct rtc_device	*rtc_dev;
     90	struct mutex		lock;
     91
     92	struct regmap		*regmap;
     93	struct regmap		*rtc_regmap;
     94
     95	const struct max77686_rtc_driver_data *drv_data;
     96	struct regmap_irq_chip_data *rtc_irq_data;
     97
     98	int rtc_irq;
     99	int virq;
    100};
    101
    102enum MAX77686_RTC_OP {
    103	MAX77686_RTC_WRITE,
    104	MAX77686_RTC_READ,
    105};
    106
    107/* These are not registers but just offsets that are mapped to addresses */
    108enum max77686_rtc_reg_offset {
    109	REG_RTC_CONTROLM = 0,
    110	REG_RTC_CONTROL,
    111	REG_RTC_UPDATE0,
    112	REG_WTSR_SMPL_CNTL,
    113	REG_RTC_SEC,
    114	REG_RTC_MIN,
    115	REG_RTC_HOUR,
    116	REG_RTC_WEEKDAY,
    117	REG_RTC_MONTH,
    118	REG_RTC_YEAR,
    119	REG_RTC_MONTHDAY,
    120	REG_ALARM1_SEC,
    121	REG_ALARM1_MIN,
    122	REG_ALARM1_HOUR,
    123	REG_ALARM1_WEEKDAY,
    124	REG_ALARM1_MONTH,
    125	REG_ALARM1_YEAR,
    126	REG_ALARM1_DATE,
    127	REG_ALARM2_SEC,
    128	REG_ALARM2_MIN,
    129	REG_ALARM2_HOUR,
    130	REG_ALARM2_WEEKDAY,
    131	REG_ALARM2_MONTH,
    132	REG_ALARM2_YEAR,
    133	REG_ALARM2_DATE,
    134	REG_RTC_AE1,
    135	REG_RTC_END,
    136};
    137
    138/* Maps RTC registers offset to the MAX77686 register addresses */
    139static const unsigned int max77686_map[REG_RTC_END] = {
    140	[REG_RTC_CONTROLM]   = MAX77686_RTC_CONTROLM,
    141	[REG_RTC_CONTROL]    = MAX77686_RTC_CONTROL,
    142	[REG_RTC_UPDATE0]    = MAX77686_RTC_UPDATE0,
    143	[REG_WTSR_SMPL_CNTL] = MAX77686_WTSR_SMPL_CNTL,
    144	[REG_RTC_SEC]        = MAX77686_RTC_SEC,
    145	[REG_RTC_MIN]        = MAX77686_RTC_MIN,
    146	[REG_RTC_HOUR]       = MAX77686_RTC_HOUR,
    147	[REG_RTC_WEEKDAY]    = MAX77686_RTC_WEEKDAY,
    148	[REG_RTC_MONTH]      = MAX77686_RTC_MONTH,
    149	[REG_RTC_YEAR]       = MAX77686_RTC_YEAR,
    150	[REG_RTC_MONTHDAY]   = MAX77686_RTC_MONTHDAY,
    151	[REG_ALARM1_SEC]     = MAX77686_ALARM1_SEC,
    152	[REG_ALARM1_MIN]     = MAX77686_ALARM1_MIN,
    153	[REG_ALARM1_HOUR]    = MAX77686_ALARM1_HOUR,
    154	[REG_ALARM1_WEEKDAY] = MAX77686_ALARM1_WEEKDAY,
    155	[REG_ALARM1_MONTH]   = MAX77686_ALARM1_MONTH,
    156	[REG_ALARM1_YEAR]    = MAX77686_ALARM1_YEAR,
    157	[REG_ALARM1_DATE]    = MAX77686_ALARM1_DATE,
    158	[REG_ALARM2_SEC]     = MAX77686_ALARM2_SEC,
    159	[REG_ALARM2_MIN]     = MAX77686_ALARM2_MIN,
    160	[REG_ALARM2_HOUR]    = MAX77686_ALARM2_HOUR,
    161	[REG_ALARM2_WEEKDAY] = MAX77686_ALARM2_WEEKDAY,
    162	[REG_ALARM2_MONTH]   = MAX77686_ALARM2_MONTH,
    163	[REG_ALARM2_YEAR]    = MAX77686_ALARM2_YEAR,
    164	[REG_ALARM2_DATE]    = MAX77686_ALARM2_DATE,
    165	[REG_RTC_AE1]	     = REG_RTC_NONE,
    166};
    167
    168static const struct regmap_irq max77686_rtc_irqs[] = {
    169	/* RTC interrupts */
    170	REGMAP_IRQ_REG(0, 0, MAX77686_RTCINT_RTC60S_MSK),
    171	REGMAP_IRQ_REG(1, 0, MAX77686_RTCINT_RTCA1_MSK),
    172	REGMAP_IRQ_REG(2, 0, MAX77686_RTCINT_RTCA2_MSK),
    173	REGMAP_IRQ_REG(3, 0, MAX77686_RTCINT_SMPL_MSK),
    174	REGMAP_IRQ_REG(4, 0, MAX77686_RTCINT_RTC1S_MSK),
    175	REGMAP_IRQ_REG(5, 0, MAX77686_RTCINT_WTSR_MSK),
    176};
    177
    178static const struct regmap_irq_chip max77686_rtc_irq_chip = {
    179	.name		= "max77686-rtc",
    180	.status_base	= MAX77686_RTC_INT,
    181	.mask_base	= MAX77686_RTC_INTM,
    182	.num_regs	= 1,
    183	.irqs		= max77686_rtc_irqs,
    184	.num_irqs	= ARRAY_SIZE(max77686_rtc_irqs),
    185};
    186
    187static const struct regmap_config max77686_rtc_regmap_config = {
    188	.reg_bits = 8,
    189	.val_bits = 8,
    190};
    191
    192static const struct max77686_rtc_driver_data max77686_drv_data = {
    193	.delay = 16000,
    194	.mask  = 0x7f,
    195	.map   = max77686_map,
    196	.alarm_enable_reg  = false,
    197	.rtc_irq_from_platform = false,
    198	.alarm_pending_status_reg = MAX77686_REG_STATUS2,
    199	.rtc_i2c_addr = MAX77686_I2C_ADDR_RTC,
    200	.rtc_irq_chip = &max77686_rtc_irq_chip,
    201	.regmap_config = &max77686_rtc_regmap_config,
    202};
    203
    204static const struct regmap_irq_chip max77714_rtc_irq_chip = {
    205	.name		= "max77714-rtc",
    206	.status_base	= MAX77686_RTC_INT,
    207	.mask_base	= MAX77686_RTC_INTM,
    208	.num_regs	= 1,
    209	.irqs		= max77686_rtc_irqs,
    210	.num_irqs	= ARRAY_SIZE(max77686_rtc_irqs) - 1, /* no WTSR on 77714 */
    211};
    212
    213static const struct max77686_rtc_driver_data max77714_drv_data = {
    214	.delay = 16000,
    215	.mask  = 0x7f,
    216	.map   = max77686_map,
    217	.alarm_enable_reg = false,
    218	.rtc_irq_from_platform = false,
    219	/* On MAX77714 RTCA1 is BIT 1 of RTCINT (0x00). Not supported by this driver. */
    220	.alarm_pending_status_reg = MAX77686_INVALID_REG,
    221	.rtc_i2c_addr = MAX77714_I2C_ADDR_RTC,
    222	.rtc_irq_chip = &max77714_rtc_irq_chip,
    223	.regmap_config = &max77686_rtc_regmap_config,
    224};
    225
    226static const struct regmap_config max77620_rtc_regmap_config = {
    227	.reg_bits = 8,
    228	.val_bits = 8,
    229	.use_single_write = true,
    230};
    231
    232static const struct max77686_rtc_driver_data max77620_drv_data = {
    233	.delay = 16000,
    234	.mask  = 0x7f,
    235	.map   = max77686_map,
    236	.alarm_enable_reg  = false,
    237	.rtc_irq_from_platform = true,
    238	.alarm_pending_status_reg = MAX77686_INVALID_REG,
    239	.rtc_i2c_addr = MAX77620_I2C_ADDR_RTC,
    240	.rtc_irq_chip = &max77686_rtc_irq_chip,
    241	.regmap_config = &max77620_rtc_regmap_config,
    242};
    243
    244static const unsigned int max77802_map[REG_RTC_END] = {
    245	[REG_RTC_CONTROLM]   = MAX77802_RTC_CONTROLM,
    246	[REG_RTC_CONTROL]    = MAX77802_RTC_CONTROL,
    247	[REG_RTC_UPDATE0]    = MAX77802_RTC_UPDATE0,
    248	[REG_WTSR_SMPL_CNTL] = MAX77802_WTSR_SMPL_CNTL,
    249	[REG_RTC_SEC]        = MAX77802_RTC_SEC,
    250	[REG_RTC_MIN]        = MAX77802_RTC_MIN,
    251	[REG_RTC_HOUR]       = MAX77802_RTC_HOUR,
    252	[REG_RTC_WEEKDAY]    = MAX77802_RTC_WEEKDAY,
    253	[REG_RTC_MONTH]      = MAX77802_RTC_MONTH,
    254	[REG_RTC_YEAR]       = MAX77802_RTC_YEAR,
    255	[REG_RTC_MONTHDAY]   = MAX77802_RTC_MONTHDAY,
    256	[REG_ALARM1_SEC]     = MAX77802_ALARM1_SEC,
    257	[REG_ALARM1_MIN]     = MAX77802_ALARM1_MIN,
    258	[REG_ALARM1_HOUR]    = MAX77802_ALARM1_HOUR,
    259	[REG_ALARM1_WEEKDAY] = MAX77802_ALARM1_WEEKDAY,
    260	[REG_ALARM1_MONTH]   = MAX77802_ALARM1_MONTH,
    261	[REG_ALARM1_YEAR]    = MAX77802_ALARM1_YEAR,
    262	[REG_ALARM1_DATE]    = MAX77802_ALARM1_DATE,
    263	[REG_ALARM2_SEC]     = MAX77802_ALARM2_SEC,
    264	[REG_ALARM2_MIN]     = MAX77802_ALARM2_MIN,
    265	[REG_ALARM2_HOUR]    = MAX77802_ALARM2_HOUR,
    266	[REG_ALARM2_WEEKDAY] = MAX77802_ALARM2_WEEKDAY,
    267	[REG_ALARM2_MONTH]   = MAX77802_ALARM2_MONTH,
    268	[REG_ALARM2_YEAR]    = MAX77802_ALARM2_YEAR,
    269	[REG_ALARM2_DATE]    = MAX77802_ALARM2_DATE,
    270	[REG_RTC_AE1]	     = MAX77802_RTC_AE1,
    271};
    272
    273static const struct regmap_irq_chip max77802_rtc_irq_chip = {
    274	.name		= "max77802-rtc",
    275	.status_base	= MAX77802_RTC_INT,
    276	.mask_base	= MAX77802_RTC_INTM,
    277	.num_regs	= 1,
    278	.irqs		= max77686_rtc_irqs, /* same masks as 77686 */
    279	.num_irqs	= ARRAY_SIZE(max77686_rtc_irqs),
    280};
    281
    282static const struct max77686_rtc_driver_data max77802_drv_data = {
    283	.delay = 200,
    284	.mask  = 0xff,
    285	.map   = max77802_map,
    286	.alarm_enable_reg  = true,
    287	.rtc_irq_from_platform = false,
    288	.alarm_pending_status_reg = MAX77686_REG_STATUS2,
    289	.rtc_i2c_addr = MAX77686_INVALID_I2C_ADDR,
    290	.rtc_irq_chip = &max77802_rtc_irq_chip,
    291};
    292
    293static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
    294				    struct max77686_rtc_info *info)
    295{
    296	u8 mask = info->drv_data->mask;
    297
    298	tm->tm_sec = data[RTC_SEC] & mask;
    299	tm->tm_min = data[RTC_MIN] & mask;
    300	tm->tm_hour = data[RTC_HOUR] & 0x1f;
    301
    302	/* Only a single bit is set in data[], so fls() would be equivalent */
    303	tm->tm_wday = ffs(data[RTC_WEEKDAY] & mask) - 1;
    304	tm->tm_mday = data[RTC_MONTHDAY] & 0x1f;
    305	tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
    306	tm->tm_year = data[RTC_YEAR] & mask;
    307	tm->tm_yday = 0;
    308	tm->tm_isdst = 0;
    309
    310	/*
    311	 * MAX77686 uses 1 bit from sec/min/hour/etc RTC registers and the
    312	 * year values are just 0..99 so add 100 to support up to 2099.
    313	 */
    314	if (!info->drv_data->alarm_enable_reg)
    315		tm->tm_year += 100;
    316}
    317
    318static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data,
    319				   struct max77686_rtc_info *info)
    320{
    321	data[RTC_SEC] = tm->tm_sec;
    322	data[RTC_MIN] = tm->tm_min;
    323	data[RTC_HOUR] = tm->tm_hour;
    324	data[RTC_WEEKDAY] = 1 << tm->tm_wday;
    325	data[RTC_MONTHDAY] = tm->tm_mday;
    326	data[RTC_MONTH] = tm->tm_mon + 1;
    327
    328	if (info->drv_data->alarm_enable_reg) {
    329		data[RTC_YEAR] = tm->tm_year;
    330		return 0;
    331	}
    332
    333	data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
    334
    335	if (tm->tm_year < 100) {
    336		dev_err(info->dev, "RTC cannot handle the year %d.\n",
    337			1900 + tm->tm_year);
    338		return -EINVAL;
    339	}
    340
    341	return 0;
    342}
    343
    344static int max77686_rtc_update(struct max77686_rtc_info *info,
    345			       enum MAX77686_RTC_OP op)
    346{
    347	int ret;
    348	unsigned int data;
    349	unsigned long delay = info->drv_data->delay;
    350
    351	if (op == MAX77686_RTC_WRITE)
    352		data = 1 << RTC_UDR_SHIFT;
    353	else
    354		data = 1 << RTC_RBUDR_SHIFT;
    355
    356	ret = regmap_update_bits(info->rtc_regmap,
    357				 info->drv_data->map[REG_RTC_UPDATE0],
    358				 data, data);
    359	if (ret < 0)
    360		dev_err(info->dev, "Fail to write update reg(ret=%d, data=0x%x)\n",
    361			ret, data);
    362	else {
    363		/* Minimum delay required before RTC update. */
    364		usleep_range(delay, delay * 2);
    365	}
    366
    367	return ret;
    368}
    369
    370static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
    371{
    372	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    373	u8 data[RTC_NR_TIME];
    374	int ret;
    375
    376	mutex_lock(&info->lock);
    377
    378	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
    379	if (ret < 0)
    380		goto out;
    381
    382	ret = regmap_bulk_read(info->rtc_regmap,
    383			       info->drv_data->map[REG_RTC_SEC],
    384			       data, ARRAY_SIZE(data));
    385	if (ret < 0) {
    386		dev_err(info->dev, "Fail to read time reg(%d)\n", ret);
    387		goto out;
    388	}
    389
    390	max77686_rtc_data_to_tm(data, tm, info);
    391
    392out:
    393	mutex_unlock(&info->lock);
    394	return ret;
    395}
    396
    397static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
    398{
    399	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    400	u8 data[RTC_NR_TIME];
    401	int ret;
    402
    403	ret = max77686_rtc_tm_to_data(tm, data, info);
    404	if (ret < 0)
    405		return ret;
    406
    407	mutex_lock(&info->lock);
    408
    409	ret = regmap_bulk_write(info->rtc_regmap,
    410				info->drv_data->map[REG_RTC_SEC],
    411				data, ARRAY_SIZE(data));
    412	if (ret < 0) {
    413		dev_err(info->dev, "Fail to write time reg(%d)\n", ret);
    414		goto out;
    415	}
    416
    417	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
    418
    419out:
    420	mutex_unlock(&info->lock);
    421	return ret;
    422}
    423
    424static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
    425{
    426	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    427	u8 data[RTC_NR_TIME];
    428	unsigned int val;
    429	const unsigned int *map = info->drv_data->map;
    430	int i, ret;
    431
    432	mutex_lock(&info->lock);
    433
    434	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
    435	if (ret < 0)
    436		goto out;
    437
    438	ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
    439			       data, ARRAY_SIZE(data));
    440	if (ret < 0) {
    441		dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
    442		goto out;
    443	}
    444
    445	max77686_rtc_data_to_tm(data, &alrm->time, info);
    446
    447	alrm->enabled = 0;
    448
    449	if (info->drv_data->alarm_enable_reg) {
    450		if (map[REG_RTC_AE1] == REG_RTC_NONE) {
    451			ret = -EINVAL;
    452			dev_err(info->dev,
    453				"alarm enable register not set(%d)\n", ret);
    454			goto out;
    455		}
    456
    457		ret = regmap_read(info->rtc_regmap, map[REG_RTC_AE1], &val);
    458		if (ret < 0) {
    459			dev_err(info->dev,
    460				"fail to read alarm enable(%d)\n", ret);
    461			goto out;
    462		}
    463
    464		if (val)
    465			alrm->enabled = 1;
    466	} else {
    467		for (i = 0; i < ARRAY_SIZE(data); i++) {
    468			if (data[i] & ALARM_ENABLE_MASK) {
    469				alrm->enabled = 1;
    470				break;
    471			}
    472		}
    473	}
    474
    475	alrm->pending = 0;
    476
    477	if (info->drv_data->alarm_pending_status_reg == MAX77686_INVALID_REG)
    478		goto out;
    479
    480	ret = regmap_read(info->regmap,
    481			  info->drv_data->alarm_pending_status_reg, &val);
    482	if (ret < 0) {
    483		dev_err(info->dev,
    484			"Fail to read alarm pending status reg(%d)\n", ret);
    485		goto out;
    486	}
    487
    488	if (val & (1 << 4)) /* RTCA1 */
    489		alrm->pending = 1;
    490
    491out:
    492	mutex_unlock(&info->lock);
    493	return ret;
    494}
    495
    496static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
    497{
    498	u8 data[RTC_NR_TIME];
    499	int ret, i;
    500	struct rtc_time tm;
    501	const unsigned int *map = info->drv_data->map;
    502
    503	if (!mutex_is_locked(&info->lock))
    504		dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
    505
    506	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
    507	if (ret < 0)
    508		goto out;
    509
    510	if (info->drv_data->alarm_enable_reg) {
    511		if (map[REG_RTC_AE1] == REG_RTC_NONE) {
    512			ret = -EINVAL;
    513			dev_err(info->dev,
    514				"alarm enable register not set(%d)\n", ret);
    515			goto out;
    516		}
    517
    518		ret = regmap_write(info->rtc_regmap, map[REG_RTC_AE1], 0);
    519	} else {
    520		ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
    521				       data, ARRAY_SIZE(data));
    522		if (ret < 0) {
    523			dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
    524			goto out;
    525		}
    526
    527		max77686_rtc_data_to_tm(data, &tm, info);
    528
    529		for (i = 0; i < ARRAY_SIZE(data); i++)
    530			data[i] &= ~ALARM_ENABLE_MASK;
    531
    532		ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
    533					data, ARRAY_SIZE(data));
    534	}
    535
    536	if (ret < 0) {
    537		dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
    538		goto out;
    539	}
    540
    541	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
    542out:
    543	return ret;
    544}
    545
    546static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
    547{
    548	u8 data[RTC_NR_TIME];
    549	int ret;
    550	struct rtc_time tm;
    551	const unsigned int *map = info->drv_data->map;
    552
    553	if (!mutex_is_locked(&info->lock))
    554		dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
    555
    556	ret = max77686_rtc_update(info, MAX77686_RTC_READ);
    557	if (ret < 0)
    558		goto out;
    559
    560	if (info->drv_data->alarm_enable_reg) {
    561		ret = regmap_write(info->rtc_regmap, map[REG_RTC_AE1],
    562				   MAX77802_ALARM_ENABLE_VALUE);
    563	} else {
    564		ret = regmap_bulk_read(info->rtc_regmap, map[REG_ALARM1_SEC],
    565				       data, ARRAY_SIZE(data));
    566		if (ret < 0) {
    567			dev_err(info->dev, "Fail to read alarm reg(%d)\n", ret);
    568			goto out;
    569		}
    570
    571		max77686_rtc_data_to_tm(data, &tm, info);
    572
    573		data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
    574		data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
    575		data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
    576		data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
    577		if (data[RTC_MONTH] & 0xf)
    578			data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
    579		if (data[RTC_YEAR] & info->drv_data->mask)
    580			data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
    581		if (data[RTC_MONTHDAY] & 0x1f)
    582			data[RTC_MONTHDAY] |= (1 << ALARM_ENABLE_SHIFT);
    583
    584		ret = regmap_bulk_write(info->rtc_regmap, map[REG_ALARM1_SEC],
    585					data, ARRAY_SIZE(data));
    586	}
    587
    588	if (ret < 0) {
    589		dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
    590		goto out;
    591	}
    592
    593	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
    594out:
    595	return ret;
    596}
    597
    598static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
    599{
    600	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    601	u8 data[RTC_NR_TIME];
    602	int ret;
    603
    604	ret = max77686_rtc_tm_to_data(&alrm->time, data, info);
    605	if (ret < 0)
    606		return ret;
    607
    608	mutex_lock(&info->lock);
    609
    610	ret = max77686_rtc_stop_alarm(info);
    611	if (ret < 0)
    612		goto out;
    613
    614	ret = regmap_bulk_write(info->rtc_regmap,
    615				info->drv_data->map[REG_ALARM1_SEC],
    616				data, ARRAY_SIZE(data));
    617
    618	if (ret < 0) {
    619		dev_err(info->dev, "Fail to write alarm reg(%d)\n", ret);
    620		goto out;
    621	}
    622
    623	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
    624	if (ret < 0)
    625		goto out;
    626
    627	if (alrm->enabled)
    628		ret = max77686_rtc_start_alarm(info);
    629out:
    630	mutex_unlock(&info->lock);
    631	return ret;
    632}
    633
    634static int max77686_rtc_alarm_irq_enable(struct device *dev,
    635					 unsigned int enabled)
    636{
    637	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    638	int ret;
    639
    640	mutex_lock(&info->lock);
    641	if (enabled)
    642		ret = max77686_rtc_start_alarm(info);
    643	else
    644		ret = max77686_rtc_stop_alarm(info);
    645	mutex_unlock(&info->lock);
    646
    647	return ret;
    648}
    649
    650static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
    651{
    652	struct max77686_rtc_info *info = data;
    653
    654	dev_dbg(info->dev, "RTC alarm IRQ: %d\n", irq);
    655
    656	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
    657
    658	return IRQ_HANDLED;
    659}
    660
    661static const struct rtc_class_ops max77686_rtc_ops = {
    662	.read_time = max77686_rtc_read_time,
    663	.set_time = max77686_rtc_set_time,
    664	.read_alarm = max77686_rtc_read_alarm,
    665	.set_alarm = max77686_rtc_set_alarm,
    666	.alarm_irq_enable = max77686_rtc_alarm_irq_enable,
    667};
    668
    669static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
    670{
    671	u8 data[2];
    672	int ret;
    673
    674	/* Set RTC control register : Binary mode, 24hour mdoe */
    675	data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
    676	data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
    677
    678	ret = regmap_bulk_write(info->rtc_regmap,
    679				info->drv_data->map[REG_RTC_CONTROLM],
    680				data, ARRAY_SIZE(data));
    681	if (ret < 0) {
    682		dev_err(info->dev, "Fail to write controlm reg(%d)\n", ret);
    683		return ret;
    684	}
    685
    686	ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
    687	return ret;
    688}
    689
    690static int max77686_init_rtc_regmap(struct max77686_rtc_info *info)
    691{
    692	struct device *parent = info->dev->parent;
    693	struct i2c_client *parent_i2c = to_i2c_client(parent);
    694	int ret;
    695
    696	if (info->drv_data->rtc_irq_from_platform) {
    697		struct platform_device *pdev = to_platform_device(info->dev);
    698
    699		info->rtc_irq = platform_get_irq(pdev, 0);
    700		if (info->rtc_irq < 0)
    701			return info->rtc_irq;
    702	} else {
    703		info->rtc_irq =  parent_i2c->irq;
    704	}
    705
    706	info->regmap = dev_get_regmap(parent, NULL);
    707	if (!info->regmap) {
    708		dev_err(info->dev, "Failed to get rtc regmap\n");
    709		return -ENODEV;
    710	}
    711
    712	if (info->drv_data->rtc_i2c_addr == MAX77686_INVALID_I2C_ADDR) {
    713		info->rtc_regmap = info->regmap;
    714		goto add_rtc_irq;
    715	}
    716
    717	info->rtc = devm_i2c_new_dummy_device(info->dev, parent_i2c->adapter,
    718					      info->drv_data->rtc_i2c_addr);
    719	if (IS_ERR(info->rtc)) {
    720		dev_err(info->dev, "Failed to allocate I2C device for RTC\n");
    721		return PTR_ERR(info->rtc);
    722	}
    723
    724	info->rtc_regmap = devm_regmap_init_i2c(info->rtc,
    725						info->drv_data->regmap_config);
    726	if (IS_ERR(info->rtc_regmap)) {
    727		ret = PTR_ERR(info->rtc_regmap);
    728		dev_err(info->dev, "Failed to allocate RTC regmap: %d\n", ret);
    729		return ret;
    730	}
    731
    732add_rtc_irq:
    733	ret = regmap_add_irq_chip(info->rtc_regmap, info->rtc_irq,
    734				  IRQF_ONESHOT | IRQF_SHARED,
    735				  0, info->drv_data->rtc_irq_chip,
    736				  &info->rtc_irq_data);
    737	if (ret < 0) {
    738		dev_err(info->dev, "Failed to add RTC irq chip: %d\n", ret);
    739		return ret;
    740	}
    741
    742	return 0;
    743}
    744
    745static int max77686_rtc_probe(struct platform_device *pdev)
    746{
    747	struct max77686_rtc_info *info;
    748	const struct platform_device_id *id = platform_get_device_id(pdev);
    749	int ret;
    750
    751	info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
    752			    GFP_KERNEL);
    753	if (!info)
    754		return -ENOMEM;
    755
    756	mutex_init(&info->lock);
    757	info->dev = &pdev->dev;
    758	info->drv_data = (const struct max77686_rtc_driver_data *)
    759		id->driver_data;
    760
    761	ret = max77686_init_rtc_regmap(info);
    762	if (ret < 0)
    763		return ret;
    764
    765	platform_set_drvdata(pdev, info);
    766
    767	ret = max77686_rtc_init_reg(info);
    768	if (ret < 0) {
    769		dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
    770		goto err_rtc;
    771	}
    772
    773	device_init_wakeup(&pdev->dev, 1);
    774
    775	info->rtc_dev = devm_rtc_device_register(&pdev->dev, id->name,
    776					&max77686_rtc_ops, THIS_MODULE);
    777
    778	if (IS_ERR(info->rtc_dev)) {
    779		ret = PTR_ERR(info->rtc_dev);
    780		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
    781		if (ret == 0)
    782			ret = -EINVAL;
    783		goto err_rtc;
    784	}
    785
    786	info->virq = regmap_irq_get_virq(info->rtc_irq_data,
    787					 MAX77686_RTCIRQ_RTCA1);
    788	if (info->virq <= 0) {
    789		ret = -ENXIO;
    790		goto err_rtc;
    791	}
    792
    793	ret = request_threaded_irq(info->virq, NULL, max77686_rtc_alarm_irq, 0,
    794				   "rtc-alarm1", info);
    795	if (ret < 0) {
    796		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
    797			info->virq, ret);
    798		goto err_rtc;
    799	}
    800
    801	return 0;
    802
    803err_rtc:
    804	regmap_del_irq_chip(info->rtc_irq, info->rtc_irq_data);
    805
    806	return ret;
    807}
    808
    809static int max77686_rtc_remove(struct platform_device *pdev)
    810{
    811	struct max77686_rtc_info *info = platform_get_drvdata(pdev);
    812
    813	free_irq(info->virq, info);
    814	regmap_del_irq_chip(info->rtc_irq, info->rtc_irq_data);
    815
    816	return 0;
    817}
    818
    819#ifdef CONFIG_PM_SLEEP
    820static int max77686_rtc_suspend(struct device *dev)
    821{
    822	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    823	int ret = 0;
    824
    825	if (device_may_wakeup(dev)) {
    826		struct max77686_rtc_info *info = dev_get_drvdata(dev);
    827
    828		ret = enable_irq_wake(info->virq);
    829	}
    830
    831	/*
    832	 * If the main IRQ (not virtual) is the parent IRQ, then it must be
    833	 * disabled during suspend because if it happens while suspended it
    834	 * will be handled before resuming I2C.
    835	 *
    836	 * Since Main IRQ is shared, all its users should disable it to be sure
    837	 * it won't fire while one of them is still suspended.
    838	 */
    839	if (!info->drv_data->rtc_irq_from_platform)
    840		disable_irq(info->rtc_irq);
    841
    842	return ret;
    843}
    844
    845static int max77686_rtc_resume(struct device *dev)
    846{
    847	struct max77686_rtc_info *info = dev_get_drvdata(dev);
    848
    849	if (!info->drv_data->rtc_irq_from_platform)
    850		enable_irq(info->rtc_irq);
    851
    852	if (device_may_wakeup(dev)) {
    853		struct max77686_rtc_info *info = dev_get_drvdata(dev);
    854
    855		return disable_irq_wake(info->virq);
    856	}
    857
    858	return 0;
    859}
    860#endif
    861
    862static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
    863			 max77686_rtc_suspend, max77686_rtc_resume);
    864
    865static const struct platform_device_id rtc_id[] = {
    866	{ "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
    867	{ "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data, },
    868	{ "max77620-rtc", .driver_data = (kernel_ulong_t)&max77620_drv_data, },
    869	{ "max77714-rtc", .driver_data = (kernel_ulong_t)&max77714_drv_data, },
    870	{},
    871};
    872MODULE_DEVICE_TABLE(platform, rtc_id);
    873
    874static struct platform_driver max77686_rtc_driver = {
    875	.driver		= {
    876		.name	= "max77686-rtc",
    877		.pm	= &max77686_rtc_pm_ops,
    878	},
    879	.probe		= max77686_rtc_probe,
    880	.remove		= max77686_rtc_remove,
    881	.id_table	= rtc_id,
    882};
    883
    884module_platform_driver(max77686_rtc_driver);
    885
    886MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
    887MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
    888MODULE_LICENSE("GPL");