cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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rtc-rv3029c2.c (22876B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Micro Crystal RV-3029 / RV-3049 rtc class driver
      4 *
      5 * Author: Gregory Hermant <gregory.hermant@calao-systems.com>
      6 *         Michael Buesch <m@bues.ch>
      7 *
      8 * based on previously existing rtc class drivers
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/i2c.h>
     13#include <linux/spi/spi.h>
     14#include <linux/bcd.h>
     15#include <linux/rtc.h>
     16#include <linux/delay.h>
     17#include <linux/of.h>
     18#include <linux/hwmon.h>
     19#include <linux/hwmon-sysfs.h>
     20#include <linux/regmap.h>
     21
     22/* Register map */
     23/* control section */
     24#define RV3029_ONOFF_CTRL		0x00
     25#define RV3029_ONOFF_CTRL_WE		BIT(0)
     26#define RV3029_ONOFF_CTRL_TE		BIT(1)
     27#define RV3029_ONOFF_CTRL_TAR		BIT(2)
     28#define RV3029_ONOFF_CTRL_EERE		BIT(3)
     29#define RV3029_ONOFF_CTRL_SRON		BIT(4)
     30#define RV3029_ONOFF_CTRL_TD0		BIT(5)
     31#define RV3029_ONOFF_CTRL_TD1		BIT(6)
     32#define RV3029_ONOFF_CTRL_CLKINT	BIT(7)
     33#define RV3029_IRQ_CTRL			0x01
     34#define RV3029_IRQ_CTRL_AIE		BIT(0)
     35#define RV3029_IRQ_CTRL_TIE		BIT(1)
     36#define RV3029_IRQ_CTRL_V1IE		BIT(2)
     37#define RV3029_IRQ_CTRL_V2IE		BIT(3)
     38#define RV3029_IRQ_CTRL_SRIE		BIT(4)
     39#define RV3029_IRQ_FLAGS		0x02
     40#define RV3029_IRQ_FLAGS_AF		BIT(0)
     41#define RV3029_IRQ_FLAGS_TF		BIT(1)
     42#define RV3029_IRQ_FLAGS_V1IF		BIT(2)
     43#define RV3029_IRQ_FLAGS_V2IF		BIT(3)
     44#define RV3029_IRQ_FLAGS_SRF		BIT(4)
     45#define RV3029_STATUS			0x03
     46#define RV3029_STATUS_VLOW1		BIT(2)
     47#define RV3029_STATUS_VLOW2		BIT(3)
     48#define RV3029_STATUS_SR		BIT(4)
     49#define RV3029_STATUS_PON		BIT(5)
     50#define RV3029_STATUS_EEBUSY		BIT(7)
     51#define RV3029_RST_CTRL			0x04
     52#define RV3029_RST_CTRL_SYSR		BIT(4)
     53#define RV3029_CONTROL_SECTION_LEN	0x05
     54
     55/* watch section */
     56#define RV3029_W_SEC			0x08
     57#define RV3029_W_MINUTES		0x09
     58#define RV3029_W_HOURS			0x0A
     59#define RV3029_REG_HR_12_24		BIT(6) /* 24h/12h mode */
     60#define RV3029_REG_HR_PM		BIT(5) /* PM/AM bit in 12h mode */
     61#define RV3029_W_DATE			0x0B
     62#define RV3029_W_DAYS			0x0C
     63#define RV3029_W_MONTHS			0x0D
     64#define RV3029_W_YEARS			0x0E
     65#define RV3029_WATCH_SECTION_LEN	0x07
     66
     67/* alarm section */
     68#define RV3029_A_SC			0x10
     69#define RV3029_A_MN			0x11
     70#define RV3029_A_HR			0x12
     71#define RV3029_A_DT			0x13
     72#define RV3029_A_DW			0x14
     73#define RV3029_A_MO			0x15
     74#define RV3029_A_YR			0x16
     75#define RV3029_A_AE_X			BIT(7)
     76#define RV3029_ALARM_SECTION_LEN	0x07
     77
     78/* timer section */
     79#define RV3029_TIMER_LOW		0x18
     80#define RV3029_TIMER_HIGH		0x19
     81
     82/* temperature section */
     83#define RV3029_TEMP_PAGE		0x20
     84
     85/* eeprom data section */
     86#define RV3029_E2P_EEDATA1		0x28
     87#define RV3029_E2P_EEDATA2		0x29
     88#define RV3029_E2PDATA_SECTION_LEN	0x02
     89
     90/* eeprom control section */
     91#define RV3029_CONTROL_E2P_EECTRL	0x30
     92#define RV3029_EECTRL_THP		BIT(0) /* temp scan interval */
     93#define RV3029_EECTRL_THE		BIT(1) /* thermometer enable */
     94#define RV3029_EECTRL_FD0		BIT(2) /* CLKOUT */
     95#define RV3029_EECTRL_FD1		BIT(3) /* CLKOUT */
     96#define RV3029_TRICKLE_1K		BIT(4) /* 1.5K resistance */
     97#define RV3029_TRICKLE_5K		BIT(5) /* 5K   resistance */
     98#define RV3029_TRICKLE_20K		BIT(6) /* 20K  resistance */
     99#define RV3029_TRICKLE_80K		BIT(7) /* 80K  resistance */
    100#define RV3029_TRICKLE_MASK		(RV3029_TRICKLE_1K |\
    101					 RV3029_TRICKLE_5K |\
    102					 RV3029_TRICKLE_20K |\
    103					 RV3029_TRICKLE_80K)
    104#define RV3029_TRICKLE_SHIFT		4
    105#define RV3029_CONTROL_E2P_XOFFS	0x31 /* XTAL offset */
    106#define RV3029_CONTROL_E2P_XOFFS_SIGN	BIT(7) /* Sign: 1->pos, 0->neg */
    107#define RV3029_CONTROL_E2P_QCOEF	0x32 /* XTAL temp drift coef */
    108#define RV3029_CONTROL_E2P_TURNOVER	0x33 /* XTAL turnover temp (in *C) */
    109#define RV3029_CONTROL_E2P_TOV_MASK	0x3F /* XTAL turnover temp mask */
    110
    111/* user ram section */
    112#define RV3029_RAM_PAGE			0x38
    113#define RV3029_RAM_SECTION_LEN		8
    114
    115struct rv3029_data {
    116	struct device		*dev;
    117	struct rtc_device	*rtc;
    118	struct regmap		*regmap;
    119	int irq;
    120};
    121
    122static int rv3029_eeprom_busywait(struct rv3029_data *rv3029)
    123{
    124	unsigned int sr;
    125	int i, ret;
    126
    127	for (i = 100; i > 0; i--) {
    128		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
    129		if (ret < 0)
    130			break;
    131		if (!(sr & RV3029_STATUS_EEBUSY))
    132			break;
    133		usleep_range(1000, 10000);
    134	}
    135	if (i <= 0) {
    136		dev_err(rv3029->dev, "EEPROM busy wait timeout.\n");
    137		return -ETIMEDOUT;
    138	}
    139
    140	return ret;
    141}
    142
    143static int rv3029_eeprom_exit(struct rv3029_data *rv3029)
    144{
    145	/* Re-enable eeprom refresh */
    146	return regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
    147				  RV3029_ONOFF_CTRL_EERE,
    148				  RV3029_ONOFF_CTRL_EERE);
    149}
    150
    151static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
    152{
    153	unsigned int sr;
    154	int ret;
    155
    156	/* Check whether we are in the allowed voltage range. */
    157	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
    158	if (ret < 0)
    159		return ret;
    160	if (sr & RV3029_STATUS_VLOW2)
    161		return -ENODEV;
    162	if (sr & RV3029_STATUS_VLOW1) {
    163		/* We clear the bits and retry once just in case
    164		 * we had a brown out in early startup.
    165		 */
    166		ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
    167					 RV3029_STATUS_VLOW1, 0);
    168		if (ret < 0)
    169			return ret;
    170		usleep_range(1000, 10000);
    171		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
    172		if (ret < 0)
    173			return ret;
    174		if (sr & RV3029_STATUS_VLOW1) {
    175			dev_err(rv3029->dev,
    176				"Supply voltage is too low to safely access the EEPROM.\n");
    177			return -ENODEV;
    178		}
    179	}
    180
    181	/* Disable eeprom refresh. */
    182	ret = regmap_update_bits(rv3029->regmap, RV3029_ONOFF_CTRL,
    183				 RV3029_ONOFF_CTRL_EERE, 0);
    184	if (ret < 0)
    185		return ret;
    186
    187	/* Wait for any previous eeprom accesses to finish. */
    188	ret = rv3029_eeprom_busywait(rv3029);
    189	if (ret < 0)
    190		rv3029_eeprom_exit(rv3029);
    191
    192	return ret;
    193}
    194
    195static int rv3029_eeprom_read(struct rv3029_data *rv3029, u8 reg,
    196			      u8 buf[], size_t len)
    197{
    198	int ret, err;
    199
    200	err = rv3029_eeprom_enter(rv3029);
    201	if (err < 0)
    202		return err;
    203
    204	ret = regmap_bulk_read(rv3029->regmap, reg, buf, len);
    205
    206	err = rv3029_eeprom_exit(rv3029);
    207	if (err < 0)
    208		return err;
    209
    210	return ret;
    211}
    212
    213static int rv3029_eeprom_write(struct rv3029_data *rv3029, u8 reg,
    214			       u8 const buf[], size_t len)
    215{
    216	unsigned int tmp;
    217	int ret, err;
    218	size_t i;
    219
    220	err = rv3029_eeprom_enter(rv3029);
    221	if (err < 0)
    222		return err;
    223
    224	for (i = 0; i < len; i++, reg++) {
    225		ret = regmap_read(rv3029->regmap, reg, &tmp);
    226		if (ret < 0)
    227			break;
    228		if (tmp != buf[i]) {
    229			tmp = buf[i];
    230			ret = regmap_write(rv3029->regmap, reg, tmp);
    231			if (ret < 0)
    232				break;
    233		}
    234		ret = rv3029_eeprom_busywait(rv3029);
    235		if (ret < 0)
    236			break;
    237	}
    238
    239	err = rv3029_eeprom_exit(rv3029);
    240	if (err < 0)
    241		return err;
    242
    243	return ret;
    244}
    245
    246static int rv3029_eeprom_update_bits(struct rv3029_data *rv3029,
    247				     u8 reg, u8 mask, u8 set)
    248{
    249	u8 buf;
    250	int ret;
    251
    252	ret = rv3029_eeprom_read(rv3029, reg, &buf, 1);
    253	if (ret < 0)
    254		return ret;
    255	buf &= ~mask;
    256	buf |= set & mask;
    257	ret = rv3029_eeprom_write(rv3029, reg, &buf, 1);
    258	if (ret < 0)
    259		return ret;
    260
    261	return 0;
    262}
    263
    264static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
    265{
    266	struct device *dev = dev_id;
    267	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    268	unsigned int flags, controls;
    269	unsigned long events = 0;
    270	int ret;
    271
    272	rtc_lock(rv3029->rtc);
    273
    274	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
    275	if (ret) {
    276		dev_warn(dev, "Read IRQ Control Register error %d\n", ret);
    277		rtc_unlock(rv3029->rtc);
    278		return IRQ_NONE;
    279	}
    280
    281	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
    282	if (ret) {
    283		dev_warn(dev, "Read IRQ Flags Register error %d\n", ret);
    284		rtc_unlock(rv3029->rtc);
    285		return IRQ_NONE;
    286	}
    287
    288	if (flags & RV3029_IRQ_FLAGS_AF) {
    289		flags &= ~RV3029_IRQ_FLAGS_AF;
    290		controls &= ~RV3029_IRQ_CTRL_AIE;
    291		events |= RTC_AF;
    292	}
    293
    294	if (events) {
    295		rtc_update_irq(rv3029->rtc, 1, events);
    296		regmap_write(rv3029->regmap, RV3029_IRQ_FLAGS, flags);
    297		regmap_write(rv3029->regmap, RV3029_IRQ_CTRL, controls);
    298	}
    299	rtc_unlock(rv3029->rtc);
    300
    301	return IRQ_HANDLED;
    302}
    303
    304static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
    305{
    306	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    307	unsigned int sr;
    308	int ret;
    309	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
    310
    311	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
    312	if (ret < 0)
    313		return ret;
    314
    315	if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
    316		return -EINVAL;
    317
    318	ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
    319			       RV3029_WATCH_SECTION_LEN);
    320	if (ret < 0)
    321		return ret;
    322
    323	tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
    324	tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
    325
    326	/* HR field has a more complex interpretation */
    327	{
    328		const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
    329
    330		if (_hr & RV3029_REG_HR_12_24) {
    331			/* 12h format */
    332			tm->tm_hour = bcd2bin(_hr & 0x1f);
    333			if (_hr & RV3029_REG_HR_PM)	/* PM flag set */
    334				tm->tm_hour += 12;
    335		} else /* 24h format */
    336			tm->tm_hour = bcd2bin(_hr & 0x3f);
    337	}
    338
    339	tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
    340	tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
    341	tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 100;
    342	tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
    343
    344	return 0;
    345}
    346
    347static int rv3029_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
    348{
    349	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    350	struct rtc_time *const tm = &alarm->time;
    351	unsigned int controls, flags;
    352	int ret;
    353	u8 regs[8];
    354
    355	ret = regmap_bulk_read(rv3029->regmap, RV3029_A_SC, regs,
    356			       RV3029_ALARM_SECTION_LEN);
    357	if (ret < 0)
    358		return ret;
    359
    360	ret = regmap_read(rv3029->regmap, RV3029_IRQ_CTRL, &controls);
    361	if (ret)
    362		return ret;
    363
    364	ret = regmap_read(rv3029->regmap, RV3029_IRQ_FLAGS, &flags);
    365	if (ret < 0)
    366		return ret;
    367
    368	tm->tm_sec = bcd2bin(regs[RV3029_A_SC - RV3029_A_SC] & 0x7f);
    369	tm->tm_min = bcd2bin(regs[RV3029_A_MN - RV3029_A_SC] & 0x7f);
    370	tm->tm_hour = bcd2bin(regs[RV3029_A_HR - RV3029_A_SC] & 0x3f);
    371	tm->tm_mday = bcd2bin(regs[RV3029_A_DT - RV3029_A_SC] & 0x3f);
    372	tm->tm_mon = bcd2bin(regs[RV3029_A_MO - RV3029_A_SC] & 0x1f) - 1;
    373	tm->tm_year = bcd2bin(regs[RV3029_A_YR - RV3029_A_SC] & 0x7f) + 100;
    374	tm->tm_wday = bcd2bin(regs[RV3029_A_DW - RV3029_A_SC] & 0x07) - 1;
    375
    376	alarm->enabled = !!(controls & RV3029_IRQ_CTRL_AIE);
    377	alarm->pending = (flags & RV3029_IRQ_FLAGS_AF) && alarm->enabled;
    378
    379	return 0;
    380}
    381
    382static int rv3029_alarm_irq_enable(struct device *dev, unsigned int enable)
    383{
    384	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    385
    386	return regmap_update_bits(rv3029->regmap, RV3029_IRQ_CTRL,
    387				  RV3029_IRQ_CTRL_AIE,
    388				  enable ? RV3029_IRQ_CTRL_AIE : 0);
    389}
    390
    391static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
    392{
    393	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    394	struct rtc_time *const tm = &alarm->time;
    395	int ret;
    396	u8 regs[8];
    397
    398	/* Activate all the alarms with AE_x bit */
    399	regs[RV3029_A_SC - RV3029_A_SC] = bin2bcd(tm->tm_sec) | RV3029_A_AE_X;
    400	regs[RV3029_A_MN - RV3029_A_SC] = bin2bcd(tm->tm_min) | RV3029_A_AE_X;
    401	regs[RV3029_A_HR - RV3029_A_SC] = (bin2bcd(tm->tm_hour) & 0x3f)
    402		| RV3029_A_AE_X;
    403	regs[RV3029_A_DT - RV3029_A_SC] = (bin2bcd(tm->tm_mday) & 0x3f)
    404		| RV3029_A_AE_X;
    405	regs[RV3029_A_MO - RV3029_A_SC] = (bin2bcd(tm->tm_mon + 1) & 0x1f)
    406		| RV3029_A_AE_X;
    407	regs[RV3029_A_DW - RV3029_A_SC] = (bin2bcd(tm->tm_wday + 1) & 0x7)
    408		| RV3029_A_AE_X;
    409	regs[RV3029_A_YR - RV3029_A_SC] = (bin2bcd(tm->tm_year - 100))
    410		| RV3029_A_AE_X;
    411
    412	/* Write the alarm */
    413	ret = regmap_bulk_write(rv3029->regmap, RV3029_A_SC, regs,
    414				RV3029_ALARM_SECTION_LEN);
    415	if (ret < 0)
    416		return ret;
    417
    418	return rv3029_alarm_irq_enable(dev, alarm->enabled);
    419}
    420
    421static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
    422{
    423	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    424	u8 regs[8];
    425	int ret;
    426
    427	regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
    428	regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
    429	regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
    430	regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
    431	regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
    432	regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
    433	regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 100);
    434
    435	ret = regmap_bulk_write(rv3029->regmap, RV3029_W_SEC, regs,
    436				RV3029_WATCH_SECTION_LEN);
    437	if (ret < 0)
    438		return ret;
    439
    440	/* clear PON and VLOW2 bits */
    441	return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
    442				  RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
    443}
    444
    445static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
    446{
    447	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    448	unsigned long vl = 0;
    449	int sr, ret = 0;
    450
    451	switch (cmd) {
    452	case RTC_VL_READ:
    453		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
    454		if (ret < 0)
    455			return ret;
    456
    457		if (sr & RV3029_STATUS_VLOW1)
    458			vl = RTC_VL_ACCURACY_LOW;
    459
    460		if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
    461			vl |= RTC_VL_DATA_INVALID;
    462
    463		return put_user(vl, (unsigned int __user *)arg);
    464
    465	case RTC_VL_CLR:
    466		return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
    467					  RV3029_STATUS_VLOW1, 0);
    468
    469	default:
    470		return -ENOIOCTLCMD;
    471	}
    472}
    473
    474static int rv3029_nvram_write(void *priv, unsigned int offset, void *val,
    475			      size_t bytes)
    476{
    477	return regmap_bulk_write(priv, RV3029_RAM_PAGE + offset, val, bytes);
    478}
    479
    480static int rv3029_nvram_read(void *priv, unsigned int offset, void *val,
    481			     size_t bytes)
    482{
    483	return regmap_bulk_read(priv, RV3029_RAM_PAGE + offset, val, bytes);
    484}
    485
    486static const struct rv3029_trickle_tab_elem {
    487	u32 r;		/* resistance in ohms */
    488	u8 conf;	/* trickle config bits */
    489} rv3029_trickle_tab[] = {
    490	{
    491		.r	= 1076,
    492		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
    493			  RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
    494	}, {
    495		.r	= 1091,
    496		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
    497			  RV3029_TRICKLE_20K,
    498	}, {
    499		.r	= 1137,
    500		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
    501			  RV3029_TRICKLE_80K,
    502	}, {
    503		.r	= 1154,
    504		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
    505	}, {
    506		.r	= 1371,
    507		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
    508			  RV3029_TRICKLE_80K,
    509	}, {
    510		.r	= 1395,
    511		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
    512	}, {
    513		.r	= 1472,
    514		.conf	= RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
    515	}, {
    516		.r	= 1500,
    517		.conf	= RV3029_TRICKLE_1K,
    518	}, {
    519		.r	= 3810,
    520		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
    521			  RV3029_TRICKLE_80K,
    522	}, {
    523		.r	= 4000,
    524		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
    525	}, {
    526		.r	= 4706,
    527		.conf	= RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
    528	}, {
    529		.r	= 5000,
    530		.conf	= RV3029_TRICKLE_5K,
    531	}, {
    532		.r	= 16000,
    533		.conf	= RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
    534	}, {
    535		.r	= 20000,
    536		.conf	= RV3029_TRICKLE_20K,
    537	}, {
    538		.r	= 80000,
    539		.conf	= RV3029_TRICKLE_80K,
    540	},
    541};
    542
    543static void rv3029_trickle_config(struct device *dev)
    544{
    545	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    546	struct device_node *of_node = dev->of_node;
    547	const struct rv3029_trickle_tab_elem *elem;
    548	int i, err;
    549	u32 ohms;
    550	u8 trickle_set_bits;
    551
    552	if (!of_node)
    553		return;
    554
    555	/* Configure the trickle charger. */
    556	err = of_property_read_u32(of_node, "trickle-resistor-ohms", &ohms);
    557	if (err) {
    558		/* Disable trickle charger. */
    559		trickle_set_bits = 0;
    560	} else {
    561		/* Enable trickle charger. */
    562		for (i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++) {
    563			elem = &rv3029_trickle_tab[i];
    564			if (elem->r >= ohms)
    565				break;
    566		}
    567		trickle_set_bits = elem->conf;
    568		dev_info(dev,
    569			 "Trickle charger enabled at %d ohms resistance.\n",
    570			 elem->r);
    571	}
    572	err = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
    573					RV3029_TRICKLE_MASK,
    574					trickle_set_bits);
    575	if (err < 0)
    576		dev_err(dev, "Failed to update trickle charger config\n");
    577}
    578
    579#ifdef CONFIG_RTC_DRV_RV3029_HWMON
    580
    581static int rv3029_read_temp(struct rv3029_data *rv3029, int *temp_mC)
    582{
    583	unsigned int temp;
    584	int ret;
    585
    586	ret = regmap_read(rv3029->regmap, RV3029_TEMP_PAGE, &temp);
    587	if (ret < 0)
    588		return ret;
    589
    590	*temp_mC = ((int)temp - 60) * 1000;
    591
    592	return 0;
    593}
    594
    595static ssize_t rv3029_hwmon_show_temp(struct device *dev,
    596				      struct device_attribute *attr,
    597				      char *buf)
    598{
    599	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    600	int ret, temp_mC;
    601
    602	ret = rv3029_read_temp(rv3029, &temp_mC);
    603	if (ret < 0)
    604		return ret;
    605
    606	return sprintf(buf, "%d\n", temp_mC);
    607}
    608
    609static ssize_t rv3029_hwmon_set_update_interval(struct device *dev,
    610						struct device_attribute *attr,
    611						const char *buf,
    612						size_t count)
    613{
    614	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    615	unsigned int th_set_bits = 0;
    616	unsigned long interval_ms;
    617	int ret;
    618
    619	ret = kstrtoul(buf, 10, &interval_ms);
    620	if (ret < 0)
    621		return ret;
    622
    623	if (interval_ms != 0) {
    624		th_set_bits |= RV3029_EECTRL_THE;
    625		if (interval_ms >= 16000)
    626			th_set_bits |= RV3029_EECTRL_THP;
    627	}
    628	ret = rv3029_eeprom_update_bits(rv3029, RV3029_CONTROL_E2P_EECTRL,
    629					RV3029_EECTRL_THE | RV3029_EECTRL_THP,
    630					th_set_bits);
    631	if (ret < 0)
    632		return ret;
    633
    634	return count;
    635}
    636
    637static ssize_t rv3029_hwmon_show_update_interval(struct device *dev,
    638						 struct device_attribute *attr,
    639						 char *buf)
    640{
    641	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    642	int ret, interval_ms;
    643	u8 eectrl;
    644
    645	ret = rv3029_eeprom_read(rv3029, RV3029_CONTROL_E2P_EECTRL,
    646				 &eectrl, 1);
    647	if (ret < 0)
    648		return ret;
    649
    650	if (eectrl & RV3029_EECTRL_THE) {
    651		if (eectrl & RV3029_EECTRL_THP)
    652			interval_ms = 16000;
    653		else
    654			interval_ms = 1000;
    655	} else {
    656		interval_ms = 0;
    657	}
    658
    659	return sprintf(buf, "%d\n", interval_ms);
    660}
    661
    662static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, rv3029_hwmon_show_temp,
    663			  NULL, 0);
    664static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO,
    665			  rv3029_hwmon_show_update_interval,
    666			  rv3029_hwmon_set_update_interval, 0);
    667
    668static struct attribute *rv3029_hwmon_attrs[] = {
    669	&sensor_dev_attr_temp1_input.dev_attr.attr,
    670	&sensor_dev_attr_update_interval.dev_attr.attr,
    671	NULL,
    672};
    673ATTRIBUTE_GROUPS(rv3029_hwmon);
    674
    675static void rv3029_hwmon_register(struct device *dev, const char *name)
    676{
    677	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
    678	struct device *hwmon_dev;
    679
    680	hwmon_dev = devm_hwmon_device_register_with_groups(dev, name, rv3029,
    681							   rv3029_hwmon_groups);
    682	if (IS_ERR(hwmon_dev)) {
    683		dev_warn(dev, "unable to register hwmon device %ld\n",
    684			 PTR_ERR(hwmon_dev));
    685	}
    686}
    687
    688#else /* CONFIG_RTC_DRV_RV3029_HWMON */
    689
    690static void rv3029_hwmon_register(struct device *dev, const char *name)
    691{
    692}
    693
    694#endif /* CONFIG_RTC_DRV_RV3029_HWMON */
    695
    696static const struct rtc_class_ops rv3029_rtc_ops = {
    697	.read_time	= rv3029_read_time,
    698	.set_time	= rv3029_set_time,
    699	.ioctl		= rv3029_ioctl,
    700	.read_alarm	= rv3029_read_alarm,
    701	.set_alarm	= rv3029_set_alarm,
    702	.alarm_irq_enable = rv3029_alarm_irq_enable,
    703};
    704
    705static int rv3029_probe(struct device *dev, struct regmap *regmap, int irq,
    706			const char *name)
    707{
    708	struct rv3029_data *rv3029;
    709	struct nvmem_config nvmem_cfg = {
    710		.name = "rv3029_nvram",
    711		.word_size = 1,
    712		.stride = 1,
    713		.size = RV3029_RAM_SECTION_LEN,
    714		.type = NVMEM_TYPE_BATTERY_BACKED,
    715		.reg_read = rv3029_nvram_read,
    716		.reg_write = rv3029_nvram_write,
    717	};
    718	int rc = 0;
    719
    720	rv3029 = devm_kzalloc(dev, sizeof(*rv3029), GFP_KERNEL);
    721	if (!rv3029)
    722		return -ENOMEM;
    723
    724	rv3029->regmap = regmap;
    725	rv3029->irq = irq;
    726	rv3029->dev = dev;
    727	dev_set_drvdata(dev, rv3029);
    728
    729	rv3029_trickle_config(dev);
    730	rv3029_hwmon_register(dev, name);
    731
    732	rv3029->rtc = devm_rtc_allocate_device(dev);
    733	if (IS_ERR(rv3029->rtc))
    734		return PTR_ERR(rv3029->rtc);
    735
    736	if (rv3029->irq > 0) {
    737		rc = devm_request_threaded_irq(dev, rv3029->irq,
    738					       NULL, rv3029_handle_irq,
    739					       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
    740					       "rv3029", dev);
    741		if (rc) {
    742			dev_warn(dev, "unable to request IRQ, alarms disabled\n");
    743			rv3029->irq = 0;
    744		}
    745	}
    746	if (!rv3029->irq)
    747		clear_bit(RTC_FEATURE_ALARM, rv3029->rtc->features);
    748
    749	rv3029->rtc->ops = &rv3029_rtc_ops;
    750	rv3029->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
    751	rv3029->rtc->range_max = RTC_TIMESTAMP_END_2079;
    752
    753	rc = devm_rtc_register_device(rv3029->rtc);
    754	if (rc)
    755		return rc;
    756
    757	nvmem_cfg.priv = rv3029->regmap;
    758	devm_rtc_nvmem_register(rv3029->rtc, &nvmem_cfg);
    759
    760	return 0;
    761}
    762
    763static const struct regmap_range rv3029_holes_range[] = {
    764	regmap_reg_range(0x05, 0x07),
    765	regmap_reg_range(0x0f, 0x0f),
    766	regmap_reg_range(0x17, 0x17),
    767	regmap_reg_range(0x1a, 0x1f),
    768	regmap_reg_range(0x21, 0x27),
    769	regmap_reg_range(0x34, 0x37),
    770};
    771
    772static const struct regmap_access_table rv3029_regs = {
    773	.no_ranges =	rv3029_holes_range,
    774	.n_no_ranges =	ARRAY_SIZE(rv3029_holes_range),
    775};
    776
    777static const struct regmap_config config = {
    778	.reg_bits = 8,
    779	.val_bits = 8,
    780	.rd_table = &rv3029_regs,
    781	.wr_table = &rv3029_regs,
    782	.max_register = 0x3f,
    783};
    784
    785#if IS_ENABLED(CONFIG_I2C)
    786
    787static int rv3029_i2c_probe(struct i2c_client *client,
    788			    const struct i2c_device_id *id)
    789{
    790	struct regmap *regmap;
    791	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK |
    792				     I2C_FUNC_SMBUS_BYTE)) {
    793		dev_err(&client->dev, "Adapter does not support SMBUS_I2C_BLOCK or SMBUS_I2C_BYTE\n");
    794		return -ENODEV;
    795	}
    796
    797	regmap = devm_regmap_init_i2c(client, &config);
    798	if (IS_ERR(regmap))
    799		return PTR_ERR(regmap);
    800
    801	return rv3029_probe(&client->dev, regmap, client->irq, client->name);
    802}
    803
    804static const struct i2c_device_id rv3029_id[] = {
    805	{ "rv3029", 0 },
    806	{ "rv3029c2", 0 },
    807	{ }
    808};
    809MODULE_DEVICE_TABLE(i2c, rv3029_id);
    810
    811static const __maybe_unused struct of_device_id rv3029_of_match[] = {
    812	{ .compatible = "microcrystal,rv3029" },
    813	{ }
    814};
    815MODULE_DEVICE_TABLE(of, rv3029_of_match);
    816
    817static struct i2c_driver rv3029_driver = {
    818	.driver = {
    819		.name = "rv3029",
    820		.of_match_table = of_match_ptr(rv3029_of_match),
    821	},
    822	.probe		= rv3029_i2c_probe,
    823	.id_table	= rv3029_id,
    824};
    825
    826static int __init rv3029_register_driver(void)
    827{
    828	return i2c_add_driver(&rv3029_driver);
    829}
    830
    831static void rv3029_unregister_driver(void)
    832{
    833	i2c_del_driver(&rv3029_driver);
    834}
    835
    836#else
    837
    838static int __init rv3029_register_driver(void)
    839{
    840	return 0;
    841}
    842
    843static void rv3029_unregister_driver(void)
    844{
    845}
    846
    847#endif
    848
    849#if IS_ENABLED(CONFIG_SPI_MASTER)
    850
    851static int rv3049_probe(struct spi_device *spi)
    852{
    853	struct regmap *regmap;
    854
    855	regmap = devm_regmap_init_spi(spi, &config);
    856	if (IS_ERR(regmap))
    857		return PTR_ERR(regmap);
    858
    859	return rv3029_probe(&spi->dev, regmap, spi->irq, "rv3049");
    860}
    861
    862static struct spi_driver rv3049_driver = {
    863	.driver = {
    864		.name    = "rv3049",
    865	},
    866	.probe   = rv3049_probe,
    867};
    868
    869static int __init rv3049_register_driver(void)
    870{
    871	return spi_register_driver(&rv3049_driver);
    872}
    873
    874static void __exit rv3049_unregister_driver(void)
    875{
    876	spi_unregister_driver(&rv3049_driver);
    877}
    878
    879#else
    880
    881static int __init rv3049_register_driver(void)
    882{
    883	return 0;
    884}
    885
    886static void __exit rv3049_unregister_driver(void)
    887{
    888}
    889
    890#endif
    891
    892static int __init rv30x9_init(void)
    893{
    894	int ret;
    895
    896	ret = rv3029_register_driver();
    897	if (ret)
    898		return ret;
    899
    900	ret = rv3049_register_driver();
    901	if (ret)
    902		rv3029_unregister_driver();
    903
    904	return ret;
    905}
    906module_init(rv30x9_init)
    907
    908static void __exit rv30x9_exit(void)
    909{
    910	rv3049_unregister_driver();
    911	rv3029_unregister_driver();
    912}
    913module_exit(rv30x9_exit)
    914
    915MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>");
    916MODULE_AUTHOR("Michael Buesch <m@bues.ch>");
    917MODULE_DESCRIPTION("Micro Crystal RV3029/RV3049 RTC driver");
    918MODULE_LICENSE("GPL");
    919MODULE_ALIAS("spi:rv3049");