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Message-Id: <20230622145800.2442116-11-hugo@hugovil.com>
Date: Thu, 22 Jun 2023 10:57:53 -0400
From: Hugo Villeneuve <hugo@...ovil.com>
To: a.zummo@...ertech.it, alexandre.belloni@...tlin.com,
robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
conor+dt@...nel.org
Cc: linux-rtc@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, hugo@...ovil.com,
Hugo Villeneuve <hvilleneuve@...onoff.com>
Subject: [PATCH v4 10/17] rtc: pcf2127: add support for multiple TS functions
From: Hugo Villeneuve <hvilleneuve@...onoff.com>
This will simplify the implementation of new variants into this driver.
Signed-off-by: Hugo Villeneuve <hvilleneuve@...onoff.com>
---
drivers/rtc/rtc-pcf2127.c | 268 ++++++++++++++++++++++++++++----------
1 file changed, 201 insertions(+), 67 deletions(-)
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 21fa42870dd4..c6bbeb1916a4 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -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,
@@ -543,28 +574,41 @@ static const struct rtc_class_ops pcf2127_rtc_ops = {
/* sysfs interface */
-static ssize_t timestamp0_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t timestamp_store(struct device *dev,
+ struct device_attribute *attr,
+ 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 (ret) {
- dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
- return ret;
+ 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 TS intermediate level detect ret=%d\n",
+ __func__, ret);
+ return ret;
+ }
}
ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
@@ -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);
- if (ret)
- return 0;
+ u8 valid_low = 0;
+ u8 valid_inter = 0;
+ unsigned int ctrl;
- ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
+ /* 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;
- if (!(ctrl1 & PCF2127_BIT_CTRL1_TSF1) &&
- !(ctrl2 & PCF2127_BIT_CTRL2_TSF2))
+ 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;
+
+ 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.
+ * Enable timestamp functions 1 to 4.
*/
- 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.
- */
- 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__);
- return ret;
+ 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__);
--
2.30.2
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