rtc: rv3032: allow setting BSM

Backup Switch Mode is currently set properly when the trickle charger is
enabled. However, in the case of a non-rechargeable battery, it is
necessary to be able to enable it, only allow that when the trickle charger
is disabled.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211018151933.76865-8-alexandre.belloni@bootlin.com

diff --git a/drivers/rtc/rtc-rv3032.c b/drivers/rtc/rtc-rv3032.c
index 1b62ed2..a3c7317 100644 (file)
--- a/drivers/rtc/rtc-rv3032.c
+++ b/drivers/rtc/rtc-rv3032.c
@@ -106,6 +106,7 @@
 struct rv3032_data {
        struct regmap *regmap;
        struct rtc_device *rtc;
+       bool trickle_charger_set;
 #ifdef CONFIG_COMMON_CLK
        struct clk_hw clkout_hw;
 #endif
@@ -402,6 +403,75 @@ static int rv3032_set_offset(struct device *dev, long offset)
                                 FIELD_PREP(RV3032_OFFSET_MSK, offset));
 }
 
+static int rv3032_param_get(struct device *dev, struct rtc_param *param)
+{
+       struct rv3032_data *rv3032 = dev_get_drvdata(dev);
+       int ret;
+
+       switch(param->param) {
+               u32 value;
+
+       case RTC_PARAM_BACKUP_SWITCH_MODE:
+               ret = regmap_read(rv3032->regmap, RV3032_PMU, &value);
+               if (ret < 0)
+                       return ret;
+
+               value = FIELD_GET(RV3032_PMU_BSM, value);
+
+               switch(value) {
+               case RV3032_PMU_BSM_DSM:
+                       param->uvalue = RTC_BSM_DIRECT;
+                       break;
+               case RV3032_PMU_BSM_LSM:
+                       param->uvalue = RTC_BSM_LEVEL;
+                       break;
+               default:
+                       param->uvalue = RTC_BSM_DISABLED;
+               }
+
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int rv3032_param_set(struct device *dev, struct rtc_param *param)
+{
+       struct rv3032_data *rv3032 = dev_get_drvdata(dev);
+
+       switch(param->param) {
+               u8 mode;
+       case RTC_PARAM_BACKUP_SWITCH_MODE:
+               if (rv3032->trickle_charger_set)
+                       return -EINVAL;
+
+               switch (param->uvalue) {
+               case RTC_BSM_DISABLED:
+                       mode = 0;
+                       break;
+               case RTC_BSM_DIRECT:
+                       mode = RV3032_PMU_BSM_DSM;
+                       break;
+               case RTC_BSM_LEVEL:
+                       mode = RV3032_PMU_BSM_LSM;
+                       break;
+               default:
+                       return -EINVAL;
+               }
+
+               return rv3032_update_cfg(rv3032, RV3032_PMU, RV3032_PMU_BSM,
+                                        FIELD_PREP(RV3032_PMU_BSM, mode));
+
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
 static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
        struct rv3032_data *rv3032 = dev_get_drvdata(dev);
@@ -541,6 +611,8 @@ static int rv3032_trickle_charger_setup(struct device *dev, struct rv3032_data *
                return 0;
        }
 
+       rv3032->trickle_charger_set = true;
+
        return rv3032_update_cfg(rv3032, RV3032_PMU,
                                 RV3032_PMU_TCR | RV3032_PMU_TCM | RV3032_PMU_BSM,
                                 val | FIELD_PREP(RV3032_PMU_TCR, i));
@@ -813,6 +885,8 @@ static const struct rtc_class_ops rv3032_rtc_ops = {
        .read_alarm = rv3032_get_alarm,
        .set_alarm = rv3032_set_alarm,
        .alarm_irq_enable = rv3032_alarm_irq_enable,
+       .param_get = rv3032_param_get,
+       .param_set = rv3032_param_set,
 };
 
 static const struct regmap_config regmap_config = {
@@ -883,6 +957,8 @@ static int rv3032_probe(struct i2c_client *client)
 
        rv3032_trickle_charger_setup(&client->dev, rv3032);
 
+       set_bit(RTC_FEATURE_BACKUP_SWITCH_MODE, rv3032->rtc->features);
+
        rv3032->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
        rv3032->rtc->range_max = RTC_TIMESTAMP_END_2099;
        rv3032->rtc->ops = &rv3032_rtc_ops;