1 files changed, 160 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 8d6eda455d81..3ec87d320766 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -25,11 +25,18 @@
 
 /* Control register 1 */
 #define PCF2127_REG_CTRL1               0x00
+#define PCF2127_BIT_CTRL1_TSF1                  BIT(4)
 /* Control register 2 */
 #define PCF2127_REG_CTRL2               0x01
+#define PCF2127_BIT_CTRL2_TSIE                  BIT(2)
+#define PCF2127_BIT_CTRL2_TSF2                  BIT(5)
 /* Control register 3 */
 #define PCF2127_REG_CTRL3               0x02
+#define PCF2127_BIT_CTRL3_BLIE                  BIT(0)
+#define PCF2127_BIT_CTRL3_BIE                   BIT(1)
 #define PCF2127_BIT_CTRL3_BLF                   BIT(2)
+#define PCF2127_BIT_CTRL3_BF                    BIT(3)
+#define PCF2127_BIT_CTRL3_BTSE                  BIT(4)
 /* Time and date registers */
 #define PCF2127_REG_SC                  0x03
 #define PCF2127_BIT_SC_OSF                      BIT(7)
@@ -46,6 +53,16 @@
 #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
+#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
@@ -305,6 +322,97 @@ static const struct watchdog_ops pcf2127_watchdog_ops = {
         .set_timeout = pcf2127_wdt_set_timeout,
 };
 
+/* sysfs interface */
+
+static ssize_t timestamp0_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t count)
+{
+        struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
+        int ret;
+
+        ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
+                                 PCF2127_BIT_CTRL1_TSF1, 0);
+        if (ret) {
+                dev_err(dev, "%s: update ctrl1 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;
+        }
+
+        ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
+        if (ret)
+                return ret;
+
+        return count;
+};
+
+static ssize_t timestamp0_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+        struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
+        struct rtc_time tm;
+        int ret;
+        unsigned char data[25];
+
+        ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
+                               sizeof(data));
+        if (ret) {
+                dev_err(dev, "%s: 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]);
+
+        ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
+        if (ret)
+                return ret;
+
+        if (!(data[PCF2127_REG_CTRL1] & PCF2127_BIT_CTRL1_TSF1) &&
+            !(data[PCF2127_REG_CTRL2] & PCF2127_BIT_CTRL2_TSF2))
+                return 0;
+
+        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);
+        /* 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]);
+        if (tm.tm_year < 70)
+                tm.tm_year += 100; /* assume we are in 1970...2069 */
+
+        ret = rtc_valid_tm(&tm);
+        if (ret)
+                return ret;
+
+        return sprintf(buf, "%llu\n",
+                       (unsigned long long)rtc_tm_to_time64(&tm));
+};
+
+static DEVICE_ATTR_RW(timestamp0);
+
+static struct attribute *pcf2127_attrs[] = {
+        &dev_attr_timestamp0.attr,
+        NULL
+};
+
+static const struct attribute_group pcf2127_attr_group = {
+        .attrs  = pcf2127_attrs,
+};
+
 static int pcf2127_probe(struct device *dev, struct regmap *regmap,
                         const char *name, bool has_nvmem)
 {
@@ -371,6 +479,58 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
         if (ret)
                 return ret;
 
+        /*
+         * Disable battery low/switch-over timestamp and interrupts.
+         * Clear battery interrupt flags which can block new trigger events.
+         * Note: This is the default chip behaviour but added to ensure
+         * correct tamper timestamp and interrupt function.
+         */
+        ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
+                                 PCF2127_BIT_CTRL3_BTSE |
+                                 PCF2127_BIT_CTRL3_BF |
+                                 PCF2127_BIT_CTRL3_BIE |
+                                 PCF2127_BIT_CTRL3_BLIE, 0);
+        if (ret) {
+                dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
+                        __func__);
+                return ret;
+        }
+
+        /*
+         * Enable timestamp function and store timestamp of first trigger
+         * event until TSF1 and TFS2 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.
+         */
+        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;
+        }
+
+        ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
+        if (ret) {
+                dev_err(dev, "%s: tamper sysfs registering failed\n",
+                        __func__);
+                return ret;
+        }
+
         return rtc_register_device(pcf2127->rtc);
 }