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SubjectRe: [PATCH v3 06/14] rtc: pcf2127: add support for multiple TS functions
On Sat, 7 Jan 2023 18:58:25 +0100
Bruno Thomsen <bruno.thomsen@gmail.com> wrote:

> Den tor. 15. dec. 2022 kl. 16.48 skrev Hugo Villeneuve <hugo@hugovil.com>:
> >
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> >
> > This will simplify the implementation of new variants into this driver.
> >
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > ---
> > drivers/rtc/rtc-pcf2127.c | 303 +++++++++++++++++++++++++++-----------
> > 1 file changed, 215 insertions(+), 88 deletions(-)
> >
> > diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> > index 38816ad065eb..3265878edc48 100644
> > --- a/drivers/rtc/rtc-pcf2127.c
> > +++ b/drivers/rtc/rtc-pcf2127.c
> > @@ -75,16 +75,19 @@
> > #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
> > +/* Tamper timestamp registers common offsets (starting from base register) */
> > +#define PCF2127_OFFSET_TS_CTL 0
> > +#define PCF2127_OFFSET_TS_SC 1
> > +#define PCF2127_OFFSET_TS_MN 2
> > +#define PCF2127_OFFSET_TS_HR 3
> > +#define PCF2127_OFFSET_TS_DM 4
> > +#define PCF2127_OFFSET_TS_MO 5
> > +#define PCF2127_OFFSET_TS_YR 6
> > +/* Tamper timestamp registers common bits */
> > #define PCF2127_BIT_TS_CTRL_TSOFF BIT(6)
> > #define PCF2127_BIT_TS_CTRL_TSM BIT(7)
> > -#define PCF2127_REG_TS_SC 0x13
> > -#define PCF2127_REG_TS_MN 0x14
> > -#define PCF2127_REG_TS_HR 0x15
> > -#define PCF2127_REG_TS_DM 0x16
> > -#define PCF2127_REG_TS_MO 0x17
> > -#define PCF2127_REG_TS_YR 0x18
> > /*
> > * RAM registers
> > * PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
> > @@ -108,6 +111,20 @@
> > PCF2127_BIT_CTRL2_WDTF | \
> > PCF2127_BIT_CTRL2_TSF2)
> >
> > +struct pcf21xx_ts_config {
> > + u8 regs_base; /* Base register to read timestamp values. */
>
> reg_base as there is only one.

Done.


>
> > + /* TS input pin driven to GND detection (supported by all variants): */
> > + u8 low_reg; /* Interrupt control register. */
> > + u8 low_bit; /* Interrupt flag in low_reg control register. */
> > + /* TS input pin driven to intermediate level between GND and supply
> > + * detection (optional feature depending on variant):
> > + */
> > + u8 inter_reg; /* Interrupt control register. */
> > + u8 inter_bit; /* Interrupt flag in inter_reg control register. */
>
> I had to read this a couple of times to understand it :)
>
> Maybe rename variables to low_ctl_reg, low_ctl_bit,
> inter_ctl_reg and inter_ctl_bit.

I modified the comments and renamed the variables so that I hope it is clearer:

+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. */
+};
+



> > + u8 ie_reg; /* Interrupt enable control register. */
> > + u8 ie_bit; /* Interrupt enable bit. */
> > +};
> > +
> > struct pcf21xx_config {
> > int max_register;
> > unsigned int has_nvmem:1;
> > @@ -117,6 +134,9 @@ 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[4];
>
> You should create a driver constant with the maximum number
> of supported timestamps, something like:
>
> #define PCF2127_MAX_TS_SUPPORTED 1
>
> and raise it to 4 when pcf2131 support is added.

Done.


>
> > + struct attribute_group attribute_group;
> > };
> >
> > struct pcf2127 {
> > @@ -124,9 +144,9 @@ 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[4]; /* Timestamp values. */
> > + bool ts_valid[4]; /* Timestamp valid indication. */
> > };
> >
> > /*
> > @@ -469,38 +489,39 @@ 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[25];
> > + unsigned char data[7]; /* To store result of reading 7 consecutive
> > + * timestamp registers.
> > + */
>
> Remove comment about data variable.

Done.


>
> >
> > - ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
> > - sizeof(data));
> > + ret = regmap_bulk_read(pcf2127->regmap, pcf2127->cfg->ts[ts_id].regs_base,
> > + data, sizeof(data));
> > if (ret) {
> > - dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
> > + dev_err(dev, "%s: bulk read error ret=%d\n", __func__, ret);
> > return ret;
> > }
> >
> > dev_dbg(dev,
> > - "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
> > - __func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
> > - data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
> > - data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
> > - data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
> > - data[PCF2127_REG_TS_YR]);
> > -
> > - tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
> > - tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
> > - tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
> > - tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
> > + "%s: raw data is ts_sc=%02x, ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
> > + __func__, data[PCF2127_OFFSET_TS_SC], data[PCF2127_OFFSET_TS_MN],
> > + data[PCF2127_OFFSET_TS_HR], data[PCF2127_OFFSET_TS_DM],
> > + data[PCF2127_OFFSET_TS_MO], data[PCF2127_OFFSET_TS_YR]);
> > +
> > + tm.tm_sec = bcd2bin(data[PCF2127_OFFSET_TS_SC] & 0x7F);
> > + tm.tm_min = bcd2bin(data[PCF2127_OFFSET_TS_MN] & 0x7F);
> > + tm.tm_hour = bcd2bin(data[PCF2127_OFFSET_TS_HR] & 0x3F);
> > + tm.tm_mday = bcd2bin(data[PCF2127_OFFSET_TS_DM] & 0x3F);
> > /* TS_MO register (month) value range: 1-12 */
> > - tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
> > - tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
> > + tm.tm_mon = bcd2bin(data[PCF2127_OFFSET_TS_MO] & 0x1F) - 1;
> > + tm.tm_year = bcd2bin(data[PCF2127_OFFSET_TS_YR]);
> > if (tm.tm_year < 70)
> > tm.tm_year += 100; /* assume we are in 1970...2069 */
> >
> > @@ -514,18 +535,21 @@ 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)
> > @@ -546,7 +570,7 @@ 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,
> > @@ -575,28 +599,40 @@ 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 LOW interrupt bit. */
> > + ret = regmap_update_bits(pcf2127->regmap,
> > + pcf2127->cfg->ts[ts_id].low_reg,
> > + pcf2127->cfg->ts[ts_id].low_bit,
> > + 0);
> > +
> > if (ret) {
> > - dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
> > + dev_err(dev, "%s: update TS low 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_bit) {
> > + /* Clear INTERMEDIATE interrupt bit if supported. */
> > + ret = regmap_update_bits(pcf2127->regmap,
> > + pcf2127->cfg->ts[ts_id].inter_reg,
> > + pcf2127->cfg->ts[ts_id].inter_bit,
> > + 0);
> > + if (ret) {
> > + dev_err(dev, "%s: update TS intermediate ret=%d\n", __func__, ret);
> > + return ret;
> > + }
> > }
> >
> > ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
> > @@ -605,34 +641,63 @@ 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].low_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].low_bit;
> > +
> > + if (pcf2127->cfg->ts[ts_id].inter_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_reg,
> > + &ctrl);
> > + if (ret)
> > + return 0;
> > +
> > + valid_inter = ctrl & pcf2127->cfg->ts[ts_id].inter_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;
> >
> > @@ -641,6 +706,12 @@ 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);
> > @@ -650,10 +721,6 @@ static struct attribute *pcf2127_attrs[] = {
> > NULL
> > };
> >
> > -static const struct attribute_group pcf2127_attr_group = {
> > - .attrs = pcf2127_attrs,
> > -};
> > -
> > enum pcf21xx_type {
> > PCF2127,
> > PCF2129,
> > @@ -670,6 +737,19 @@ 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] = {
> > + .regs_base = PCF2127_REG_TS1_BASE,
> > + .low_reg = PCF2127_REG_CTRL1,
> > + .low_bit = PCF2127_BIT_CTRL1_TSF1,
> > + .inter_reg = PCF2127_REG_CTRL2,
> > + .inter_bit = PCF2127_BIT_CTRL2_TSF2,
> > + .ie_reg = PCF2127_REG_CTRL2,
> > + .ie_bit = PCF2127_BIT_CTRL2_TSIE,
> > + },
> > + .attribute_group = {
> > + .attrs = pcf2127_attrs,
> > + },
> > },
> > [PCF2129] = {
> > .max_register = 0x19,
> > @@ -680,15 +760,81 @@ 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] = {
> > + .regs_base = PCF2127_REG_TS1_BASE,
> > + .low_reg = PCF2127_REG_CTRL1,
> > + .low_bit = PCF2127_BIT_CTRL1_TSF1,
> > + .inter_reg = PCF2127_REG_CTRL2,
> > + .inter_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].regs_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 low_bit is defined.
> > + */
> > + if (pcf2127->cfg->ts[ts_id].low_bit == 0) {
> > + dev_err(dev, "%s: tamper detection LOW 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)
> > {
> > struct pcf2127 *pcf2127;
> > int ret = 0;
> > unsigned int val;
> > + int i;
> >
> > dev_dbg(dev, "%s\n", __func__);
> >
> > @@ -813,34 +959,15 @@ 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 (i = 0; i < pcf2127->cfg->ts_count; i++) {
>
> Just define the loop counter variable inline.
>
> for (int i = 0; i < pcf2127->cfg->ts_count; i++) {

Done.


>
> > + 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
> >
>


--
Hugo Villeneuve <hugo@hugovil.com>

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