Add sysfs interface to enable the EVINx pins and read the time-stamp
events from EVINX.
Signed-off-by: Markus Burri <markus.burri@xxxxxx>
---
drivers/rtc/rtc-rv8803.c | 277 +++++++++++++++++++++++++++++++++++++++
1 file changed, 277 insertions(+)
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index a4f2f53..754657d 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -10,6 +10,7 @@
#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/bitfield.h>
+#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
@@ -680,6 +681,276 @@ static int rv8803_nvram_read(void *priv, unsigned int offset,
return 0;
}
+static int rv8803_ts_event_write_evin(int evin, struct rv8803_data *rv8803, int pullup_down,
+ int trigger, int filter)
+{
+ int ret;
+ u8 reg_mask;
+ struct i2c_client *client = rv8803->client;
+
+ /* according to data-sheet, "1" is not valid for filter */
+ if (evin >= NO_OF_EVIN || filter == 1 || filter > EVIN_FILTER_MAX)
+ return -EINVAL;
+
+ /* set EVENTx pull-up edge trigger */
+ ret = rv8803_read_reg(client, evin_cfg_reg[evin]);
+ if (ret < 0)
+ return ret;
+ reg_mask = ret;
+ if (pullup_down != -1) {
+ reg_mask &= ~RX8901_EVENTx_CFG_PUPD;
+ reg_mask |= FIELD_PREP(RX8901_EVENTx_CFG_PUPD, pullup_down);
+ }
+ if (trigger != -1) {
+ reg_mask &= ~RX8901_EVENTx_CFG_POL;
+ reg_mask |= FIELD_PREP(RX8901_EVENTx_CFG_POL, trigger);
+ }
+ ret = rv8803_write_reg(client, evin_cfg_reg[evin], reg_mask);
+ if (ret < 0)
+ return ret;
+
+ /* set EVENTx noise filter */
+ if (filter != -1) {
+ ret = rv8803_write_reg(client, evin_flt_reg[evin], filter);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static ssize_t enable_store(struct device *dev, struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ int ret;
+ int i;
+ unsigned long tmo;
+ u8 reg;
+ u8 reg_mask;
+ struct rv8803_data *rv8803 = dev_get_drvdata(dev->parent);
+ struct i2c_client *client = rv8803->client;
+
+ /* EVINxCPEN | EVINxEN */;
+ const u8 reg_mask_evin_en = GENMASK(5, 3) | GENMASK(2, 0);
+
+ bool enable = (strstr(buf, "1") == buf) ? true : false;
+
+ guard(mutex)(&rv8803->flags_lock);
+
+ /* check if event detection status match requested mode */
+ ret = rv8803_read_reg(client, RX8901_EVIN_EN);
+ if (ret < 0)
+ return ret;
+
+ /* requested mode match current state -> nothing to do */
+ if (ret == (enable ? reg_mask_evin_en : 0))
+ return count;
+
+ dev_info(&client->dev, "%s time-stamp event detection\n",
+ (enable) ? "configure" : "disable");
+
+ /* 1. disable event detection interrupt */
+ ret = rv8803_read_reg(rv8803->client, RV8803_CTRL);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ret & ~RV8803_CTRL_EIE);
+ if (ret)
+ return ret;
+
+ /* 2. disable events for configuration */
+ ret = rv8803_write_reg(client, RX8901_EVIN_EN, 0);
+ if (ret < 0)
+ return ret;
+
+ /* for disable no configuration is needed */
+ if (!enable)
+ return count;
+
+ /* 3. set EVENTx pull-up edge trigger and noise filter */
+ for (i = 0; i < NO_OF_EVIN; ++i) {
+ ret = rv8803_ts_event_write_evin(i, rv8803, pull_up_1M, falling_edge, 0);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* 4. enable EVENTx interrupt and VBATL,VDDL */
+ ret = rv8803_read_reg(client, RX8901_EVNT_INTE);
+ if (ret < 0)
+ return ret;
+ reg_mask = BIT(5) | BIT(6) | BIT(7); /* EVINxIEN 1-3 */
+ reg_mask |= BIT(3) | BIT(1); /* VBATLIEN | VDDLIEN */
+ reg = (ret & ~reg_mask) | reg_mask;
+ ret = rv8803_write_reg(client, RX8901_EVNT_INTE, reg);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * 5. set BUF1 inhibit and interrupt every 1 event
+ * NOTE: BUF2-3 are not used in FIFO-mode
+ */
+ ret = rv8803_write_reg(client, RX8901_BUF1_CFG1, 0x01);
+ if (ret < 0)
+ return ret;
+
+ /* 6. clean and init for BUFx and event counter 1-3 and trigger cmd */
+ reg = BIT(7) | GENMASK(6, 4);
+ reg |= BIT(0); /* CMDTRGEN */
+ ret = rv8803_write_reg(client, RX8901_WRCMD_CFG, reg);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(client, RX8901_WRCMD_TRG, 0xFF);
+ if (ret < 0)
+ return ret;
+ tmo = jiffies + msecs_to_jiffies(100); /* timeout 100ms */
+ do {
+ usleep_range(10, 2000);
+ ret = rv8803_read_reg(client, RX8901_WRCMD_TRG);
+ if (ret < 0)
+ return ret;
+ if (time_after(jiffies, tmo))
+ return -EBUSY;
+ } while (ret);
+
+ /* 7. enable event detection interrupt */
+ ret = rv8803_read_reg(rv8803->client, RV8803_CTRL);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ret | RV8803_CTRL_EIE);
+ if (ret)
+ return ret;
+
+ /* 8. / 10. enable events for configuration in FIFO mode */
+ ret = rv8803_write_reg(client, RX8901_EVIN_EN, reg_mask_evin_en);
+ if (ret < 0)
+ return ret;
+
+ return count;
+}
+
+static ssize_t read_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ int ret;
+ int ev_idx;
+ int num_events;
+ unsigned long long time_s;
+ int time_ms;
+ int offset = 0;
+ u8 reg_mask;
+ u8 data[10];
+ struct rtc_time tm;
+
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct rv8803_data *rv8803 = dev_get_drvdata(dev->parent);
+
+ guard(mutex)(&rv8803->flags_lock);
+
+ /*
+ * For detailed description see datasheet:
+ * - Reading Time Stamp Data (FIFO mode)
+ */
+
+ /* check interrupt source is from event 1-3 */
+ ret = rv8803_read_reg(client, RX8901_EVNT_INTF);
+ if (ret < 0)
+ return ret;
+
+ /* CHECK for EVF bit */
+ if (ret & BIT(2)) {
+ /* clear EVINxF 1-3 */
+ reg_mask = BIT(5) | BIT(6) | BIT(7);
+ ret = rv8803_write_reg(client, RX8901_EVNT_INTF, ret & ~reg_mask);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* check interrupt source is from event 1-3 */
+ ret = rv8803_read_reg(client, RX8901_BUF_INTF);
+ if (ret < 0)
+ return ret;
+ if (ret & RX8901_BUF_INTF_BUF1F) {
+ /* disable interrupts */
+ ret = rv8803_read_reg(client, RV8803_CTRL);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(client, RV8803_CTRL, ret & ~RV8803_CTRL_EIE);
+ if (ret < 0)
+ return ret;
+
+ /* clear interrupt flag */
+ ret = rv8803_read_reg(client, RX8901_BUF_INTF);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(client, RX8901_BUF_INTF, ret & ~RX8901_BUF_INTF_BUF1F);
+ if (ret < 0)
+ return ret;
+ }
+
+ /* test if there are events available */
+ ret = rv8803_read_reg(client, RX8901_BUF1_STAT);
+ if (ret < 0)
+ return ret;
+ num_events = ret & RX8901_BUFx_STAT_PTR;
+
+ if (num_events) {
+ ret = rv8803_read_regs(client, 0x60, ARRAY_SIZE(data), data);
+ if (ret < 0)
+ return ret;
+
+ tm.tm_sec = bcd2bin(data[2]);
+ tm.tm_min = bcd2bin(data[3]);
+ tm.tm_hour = bcd2bin(data[4]);
+ tm.tm_mday = bcd2bin(data[5]);
+ tm.tm_mon = bcd2bin(data[6]) - 1;
+ tm.tm_year = bcd2bin(data[7]) + 100;
+ tm.tm_wday = -1;
+ tm.tm_yday = -1;
+ tm.tm_isdst = -1;
+
+ ret = rtc_valid_tm(&tm);
+ if (ret)
+ return ret;
+
+ /* calculate 1/1024 -> ms */
+ time_ms = (1000 * ((data[1] << 2) | (data[0] >> 6))) / 1024;
+ time_s = rtc_tm_to_time64(&tm);
+
+ offset += snprintf(buf + offset, PAGE_SIZE - offset, "%llu.%03d", time_s, time_ms);
+ for (ev_idx = 0; trg_status_txt[ev_idx].txt; ++ev_idx)
+ if (data[9] & trg_status_txt[ev_idx].val)
+ offset += snprintf(buf + offset, PAGE_SIZE - offset, " %s=%d",
+ trg_status_txt[ev_idx].txt,
+ !!(trg_status_txt[ev_idx].val & data[8]));
+ offset += snprintf(buf + offset, PAGE_SIZE - offset, "\n");
+
+ /* according to the datasheet we have to wait for 1ms */
+ usleep_range(1000, 2000);
+ }
+
+ /* re-enable interrupts */
+ ret = rv8803_read_reg(client, RV8803_CTRL);
+ if (ret < 0)
+ return ret;
+ ret = rv8803_write_reg(client, RV8803_CTRL, ret | RV8803_CTRL_EIE);
+ if (ret < 0)
+ return ret;
+
+ return offset;
+}
+
+static DEVICE_ATTR_WO(enable);
+static DEVICE_ATTR_RO(read);
+
+static struct attribute *rv8803_rtc_event_attrs[] = {
+ &dev_attr_enable.attr,
+ &dev_attr_read.attr,
+ NULL
+};
+
+static const struct attribute_group rv8803_rtc_sysfs_event_files = {
+ .name = "tamper",
+ .attrs = rv8803_rtc_event_attrs,
+};
+
static const struct rtc_class_ops rv8803_rtc_ops = {
.read_time = rv8803_get_time,
.set_time = rv8803_set_time,
@@ -854,6 +1125,12 @@ static int rv8803_probe(struct i2c_client *client)
if (err)
return err;
+ if (rv8803->type == rx_8901) {
+ err = rtc_add_group(rv8803->rtc, &rv8803_rtc_sysfs_event_files);
+ if (err)
+ return err;
+ }
+
rv8803->rtc->ops = &rv8803_rtc_ops;
rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
--
2.39.5
