Commit 420cc9e8 authored by Hugo Villeneuve's avatar Hugo Villeneuve Committed by Alexandre Belloni
Browse files

rtc: pcf2127: add support for multiple TS functions 



This will simplify the implementation of new variants into this driver.

Signed-off-by: default avatarHugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20230622145800.2442116-11-hugo@hugovil.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent fc16599e

drivers/rtc/rtc-pcf2127.c

+201 −67
Original line number Diff line number Diff line
@@ -59,8 +59,8 @@ 
#define PCF2127_BIT_WD_CTL_CD0			BIT(6)

#define PCF2127_BIT_WD_CTL_CD1			BIT(7)

#define PCF2127_REG_WD_VAL		0x11

/* Tamper timestamp registers */

#define PCF2127_REG_TS_CTRL		0x12

/* Tamper timestamp1 registers */

#define PCF2127_REG_TS1_BASE		0x12

#define PCF2127_BIT_TS_CTRL_TSOFF		BIT(6)

#define PCF2127_BIT_TS_CTRL_TSM			BIT(7)

/*
@@ -86,12 +86,36 @@ 
		PCF2127_BIT_CTRL2_WDTF | \

		PCF2127_BIT_CTRL2_TSF2)



#define PCF2127_MAX_TS_SUPPORTED	1



enum pcf21xx_type {

	PCF2127,

	PCF2129,

	PCF21XX_LAST_ID

};



struct pcf21xx_ts_config {

	u8 reg_base; /* Base register to read timestamp values. */



	/*

	 * If the TS input pin is driven to GND, an interrupt can be generated

	 * (supported by all variants).

	 */

	u8 gnd_detect_reg; /* Interrupt control register address. */

	u8 gnd_detect_bit; /* Interrupt bit. */



	/*

	 * If the TS input pin is driven to an intermediate level between GND

	 * and supply, an interrupt can be generated (optional feature depending

	 * on variant).

	 */

	u8 inter_detect_reg; /* Interrupt control register address. */

	u8 inter_detect_bit; /* Interrupt bit. */



	u8 ie_reg; /* Interrupt enable control register. */

	u8 ie_bit; /* Interrupt enable bit. */

};



struct pcf21xx_config {

	int type; /* IC variant */

	int max_register;
@@ -102,6 +126,9 @@ struct pcf21xx_config { 
	u8 reg_wd_ctl; /* Watchdog control register. */

	u8 reg_wd_val; /* Watchdog value register. */

	u8 reg_clkout; /* Clkout register. */

	unsigned int ts_count;

	struct pcf21xx_ts_config ts[PCF2127_MAX_TS_SUPPORTED];

	struct attribute_group attribute_group;

};



struct pcf2127 {
@@ -109,9 +136,9 @@ struct pcf2127 { 
	struct watchdog_device wdd;

	struct regmap *regmap;

	const struct pcf21xx_config *cfg;

	time64_t ts;

	bool ts_valid;

	bool irq_enabled;

	time64_t ts[PCF2127_MAX_TS_SUPPORTED]; /* Timestamp values. */

	bool ts_valid[PCF2127_MAX_TS_SUPPORTED];  /* Timestamp valid indication. */

};



/*
@@ -441,18 +468,19 @@ static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
}



/*

 * This function reads ctrl2 register, caller is responsible for calling

 * pcf2127_wdt_active_ping()

 * This function reads one timestamp function data, caller is responsible for

 * calling pcf2127_wdt_active_ping()

 */

static int pcf2127_rtc_ts_read(struct device *dev, time64_t *ts)

static int pcf2127_rtc_ts_read(struct device *dev, time64_t *ts,

			       int ts_id)

{

	struct pcf2127 *pcf2127 = dev_get_drvdata(dev);

	struct rtc_time tm;

	int ret;

	unsigned char data[7];



	ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_TS_CTRL, data,

			       sizeof(data));

	ret = regmap_bulk_read(pcf2127->regmap, pcf2127->cfg->ts[ts_id].reg_base,

			       data, sizeof(data));

	if (ret) {

		dev_err(dev, "%s: read error ret=%d\n", __func__, ret);

		return ret;
@@ -482,18 +510,21 @@ static int pcf2127_rtc_ts_read(struct device *dev, time64_t *ts) 
	return 0;

};



static void pcf2127_rtc_ts_snapshot(struct device *dev)

static void pcf2127_rtc_ts_snapshot(struct device *dev, int ts_id)

{

	struct pcf2127 *pcf2127 = dev_get_drvdata(dev);

	int ret;



	if (ts_id >= pcf2127->cfg->ts_count)

		return;



	/* Let userspace read the first timestamp */

	if (pcf2127->ts_valid)

	if (pcf2127->ts_valid[ts_id])

		return;



	ret = pcf2127_rtc_ts_read(dev, &pcf2127->ts);

	ret = pcf2127_rtc_ts_read(dev, &pcf2127->ts[ts_id], ts_id);

	if (!ret)

		pcf2127->ts_valid = true;

		pcf2127->ts_valid[ts_id] = true;

}



static irqreturn_t pcf2127_rtc_irq(int irq, void *dev)
@@ -514,7 +545,7 @@ static irqreturn_t pcf2127_rtc_irq(int irq, void *dev) 
		return IRQ_NONE;



	if (ctrl1 & PCF2127_BIT_CTRL1_TSF1 || ctrl2 & PCF2127_BIT_CTRL2_TSF2)

		pcf2127_rtc_ts_snapshot(dev);

		pcf2127_rtc_ts_snapshot(dev, 0);



	if (ctrl1 & PCF2127_CTRL1_IRQ_MASK)

		regmap_write(pcf2127->regmap, PCF2127_REG_CTRL1,
@@ -543,29 +574,42 @@ static const struct rtc_class_ops pcf2127_rtc_ops = { 


/* sysfs interface */



static ssize_t timestamp0_store(struct device *dev,

static ssize_t timestamp_store(struct device *dev,

			       struct device_attribute *attr,

				const char *buf, size_t count)

			       const char *buf, size_t count, int ts_id)

{

	struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);

	int ret;



	if (ts_id >= pcf2127->cfg->ts_count)

		return 0;



	if (pcf2127->irq_enabled) {

		pcf2127->ts_valid = false;

		pcf2127->ts_valid[ts_id] = false;

	} else {

		ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,

			PCF2127_BIT_CTRL1_TSF1, 0);

		/* Always clear GND interrupt bit. */

		ret = regmap_update_bits(pcf2127->regmap,

					 pcf2127->cfg->ts[ts_id].gnd_detect_reg,

					 pcf2127->cfg->ts[ts_id].gnd_detect_bit,

					 0);



		if (ret) {

			dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);

			dev_err(dev, "%s: update TS gnd detect ret=%d\n", __func__, ret);

			return ret;

		}



		ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,

			PCF2127_BIT_CTRL2_TSF2, 0);

		if (pcf2127->cfg->ts[ts_id].inter_detect_bit) {

			/* Clear intermediate level interrupt bit if supported. */

			ret = regmap_update_bits(pcf2127->regmap,

						 pcf2127->cfg->ts[ts_id].inter_detect_reg,

						 pcf2127->cfg->ts[ts_id].inter_detect_bit,

						 0);

			if (ret) {

			dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);

				dev_err(dev, "%s: update TS intermediate level detect ret=%d\n",

					__func__, ret);

				return ret;

			}

		}



		ret = pcf2127_wdt_active_ping(&pcf2127->wdd);

		if (ret)
@@ -573,34 +617,63 @@ static ssize_t timestamp0_store(struct device *dev, 
	}



	return count;

}



static ssize_t timestamp0_store(struct device *dev,

				struct device_attribute *attr,

				const char *buf, size_t count)

{

	return timestamp_store(dev, attr, buf, count, 0);

};



static ssize_t timestamp0_show(struct device *dev,

			       struct device_attribute *attr, char *buf)

static ssize_t timestamp_show(struct device *dev,

			      struct device_attribute *attr, char *buf,

			      int ts_id)

{

	struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);

	unsigned int ctrl1, ctrl2;

	int ret;

	time64_t ts;



	if (ts_id >= pcf2127->cfg->ts_count)

		return 0;



	if (pcf2127->irq_enabled) {

		if (!pcf2127->ts_valid)

		if (!pcf2127->ts_valid[ts_id])

			return 0;

		ts = pcf2127->ts;

		ts = pcf2127->ts[ts_id];

	} else {

		ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1, &ctrl1);

		u8 valid_low = 0;

		u8 valid_inter = 0;

		unsigned int ctrl;



		/* Check if TS input pin is driven to GND, supported by all

		 * variants.

		 */

		ret = regmap_read(pcf2127->regmap,

				  pcf2127->cfg->ts[ts_id].gnd_detect_reg,

				  &ctrl);

		if (ret)

			return 0;



		ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);

		valid_low = ctrl & pcf2127->cfg->ts[ts_id].gnd_detect_bit;



		if (pcf2127->cfg->ts[ts_id].inter_detect_bit) {

			/* Check if TS input pin is driven to intermediate level

			 * between GND and supply, if supported by variant.

			 */

			ret = regmap_read(pcf2127->regmap,

					  pcf2127->cfg->ts[ts_id].inter_detect_reg,

					  &ctrl);

			if (ret)

				return 0;



		if (!(ctrl1 & PCF2127_BIT_CTRL1_TSF1) &&

		    !(ctrl2 & PCF2127_BIT_CTRL2_TSF2))

			valid_inter = ctrl & pcf2127->cfg->ts[ts_id].inter_detect_bit;

		}



		if (!valid_low && !valid_inter)

			return 0;



		ret = pcf2127_rtc_ts_read(dev->parent, &ts);

		ret = pcf2127_rtc_ts_read(dev->parent, &ts, ts_id);

		if (ret)

			return 0;
@@ -609,6 +682,12 @@ static ssize_t timestamp0_show(struct device *dev, 
			return ret;

	}

	return sprintf(buf, "%llu\n", (unsigned long long)ts);

}



static ssize_t timestamp0_show(struct device *dev,

			       struct device_attribute *attr, char *buf)

{

	return timestamp_show(dev, attr, buf, 0);

};



static DEVICE_ATTR_RW(timestamp0);
@@ -618,10 +697,6 @@ static struct attribute *pcf2127_attrs[] = { 
	NULL

};



static const struct attribute_group pcf2127_attr_group = {

	.attrs	= pcf2127_attrs,

};



static struct pcf21xx_config pcf21xx_cfg[] = {

	[PCF2127] = {

		.type = PCF2127,
@@ -633,6 +708,19 @@ static struct pcf21xx_config pcf21xx_cfg[] = { 
		.reg_wd_ctl = PCF2127_REG_WD_CTL,

		.reg_wd_val = PCF2127_REG_WD_VAL,

		.reg_clkout = PCF2127_REG_CLKOUT,

		.ts_count = 1,

		.ts[0] = {

			.reg_base  = PCF2127_REG_TS1_BASE,

			.gnd_detect_reg = PCF2127_REG_CTRL1,

			.gnd_detect_bit = PCF2127_BIT_CTRL1_TSF1,

			.inter_detect_reg = PCF2127_REG_CTRL2,

			.inter_detect_bit = PCF2127_BIT_CTRL2_TSF2,

			.ie_reg    = PCF2127_REG_CTRL2,

			.ie_bit    = PCF2127_BIT_CTRL2_TSIE,

		},

		.attribute_group = {

			.attrs	= pcf2127_attrs,

		},

	},

	[PCF2129] = {

		.type = PCF2129,
@@ -644,9 +732,74 @@ static struct pcf21xx_config pcf21xx_cfg[] = { 
		.reg_wd_ctl = PCF2127_REG_WD_CTL,

		.reg_wd_val = PCF2127_REG_WD_VAL,

		.reg_clkout = PCF2127_REG_CLKOUT,

		.ts_count = 1,

		.ts[0] = {

			.reg_base  = PCF2127_REG_TS1_BASE,

			.gnd_detect_reg = PCF2127_REG_CTRL1,

			.gnd_detect_bit = PCF2127_BIT_CTRL1_TSF1,

			.inter_detect_reg = PCF2127_REG_CTRL2,

			.inter_detect_bit = PCF2127_BIT_CTRL2_TSF2,

			.ie_reg    = PCF2127_REG_CTRL2,

			.ie_bit    = PCF2127_BIT_CTRL2_TSIE,

		},

		.attribute_group = {

			.attrs	= pcf2127_attrs,

		},

	},

};



/*

 * Enable timestamp function and corresponding interrupt(s).

 */

static int pcf2127_enable_ts(struct device *dev, int ts_id)

{

	struct pcf2127 *pcf2127 = dev_get_drvdata(dev);

	int ret;



	if (ts_id >= pcf2127->cfg->ts_count) {

		dev_err(dev, "%s: invalid tamper detection ID (%d)\n",

			__func__, ts_id);

		return -EINVAL;

	}



	/* Enable timestamp function. */

	ret = regmap_update_bits(pcf2127->regmap,

				 pcf2127->cfg->ts[ts_id].reg_base,

				 PCF2127_BIT_TS_CTRL_TSOFF |

				 PCF2127_BIT_TS_CTRL_TSM,

				 PCF2127_BIT_TS_CTRL_TSM);

	if (ret) {

		dev_err(dev, "%s: tamper detection config (ts%d_ctrl) failed\n",

			__func__, ts_id);

		return ret;

	}



	/* TS input pin driven to GND detection is supported by all variants.

	 * Make sure that interrupt bit is defined.

	 */

	if (pcf2127->cfg->ts[ts_id].gnd_detect_bit == 0) {

		dev_err(dev, "%s: tamper detection to GND configuration invalid\n",

			__func__);

		return ret;

	}



	/*

	 * Enable interrupt generation when TSF timestamp flag is set.

	 * Interrupt signals are open-drain outputs and can be left floating if

	 * unused.

	 */

	ret = regmap_update_bits(pcf2127->regmap, pcf2127->cfg->ts[ts_id].ie_reg,

				 pcf2127->cfg->ts[ts_id].ie_bit,

				 pcf2127->cfg->ts[ts_id].ie_bit);

	if (ret) {

		dev_err(dev, "%s: tamper detection TSIE%d config failed\n",

			__func__, ts_id);

		return ret;

	}



	return ret;

}



static int pcf2127_probe(struct device *dev, struct regmap *regmap,

			 int alarm_irq, const char *name, const struct pcf21xx_config *config)

{
@@ -777,34 +930,15 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap, 
	}



	/*

	 * Enable timestamp function and store timestamp of first trigger

	 * event until TSF1 and TSF2 interrupt flags are cleared.

	 */

	ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,

				 PCF2127_BIT_TS_CTRL_TSOFF |

				 PCF2127_BIT_TS_CTRL_TSM,

				 PCF2127_BIT_TS_CTRL_TSM);

	if (ret) {

		dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",

			__func__);

		return ret;

	}



	/*

	 * Enable interrupt generation when TSF1 or TSF2 timestamp flags

	 * are set. Interrupt signal is an open-drain output and can be

	 * left floating if unused.

	 * Enable timestamp functions 1 to 4.

	 */

	ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,

				 PCF2127_BIT_CTRL2_TSIE,

				 PCF2127_BIT_CTRL2_TSIE);

	if (ret) {

		dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",

			__func__);

	for (int i = 0; i < pcf2127->cfg->ts_count; i++) {

		ret = pcf2127_enable_ts(dev, i);

		if (ret)

			return ret;

	}



	ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);

	ret = rtc_add_group(pcf2127->rtc, &pcf2127->cfg->attribute_group);

	if (ret) {

		dev_err(dev, "%s: tamper sysfs registering failed\n",

			__func__);