The pcf85363 provides a high-impedance (hi-Z) mode for its output. This
mode can be used to reduce power consumption in applications where the
RTC output is only required as a clock/interrupt source when the system
runs in low-power mode (i.e. serving as a clock source for a PMU when
the system is down). If the output is not needed, it can also be
completely disabled.
This implementation adds support for a hi-Z output and also uses simple
pm operations (suspend and resume) to switch the output mode from hi-Z
in normal operation to the required operation mode in sleep mode
(currently either clock or interrupt) if the "sleep" value for the
hiz-output was set.
In order to make use of the hi-Z output modeling via device tree,
check if the new "hiz-output" property is defined and set the hi-Z
mode accordingly.
Signed-off-by: Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
---
drivers/rtc/rtc-pcf85363.c | 62 +++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 61 insertions(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 540042b9eec8..82eaf8de8b33 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -110,9 +110,17 @@
#define NVRAM_SIZE 0x40
+enum pcf85363_hiz_output_t {
+ PCF85363_HIZ_OFF,
+ PCF85363_HIZ_ON,
+ PCF85363_HIZ_SLEEP,
+};
+
struct pcf85363 {
struct rtc_device *rtc;
struct regmap *regmap;
+
+ enum pcf85363_hiz_output_t hiz_output;
};
struct pcf85x63_config {
@@ -403,6 +411,7 @@ static int pcf85363_probe(struct i2c_client *client)
};
int ret, i, err;
bool wakeup_source;
+ const char *hiz_output = NULL;
if (data)
config = data;
@@ -433,9 +442,32 @@ static int pcf85363_probe(struct i2c_client *client)
pcf85363->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
+ if (device_property_present(&client->dev, "hiz-output")) {
+ ret = device_property_read_string(&client->dev, "hiz-output",
+ &hiz_output);
+ if (ret)
+ return ret;
+
+ if (!strcmp(hiz_output, "enabled")) {
+ pcf85363->hiz_output = PCF85363_HIZ_ON;
+ } else if (!strcmp(hiz_output, "sleep")) {
+ pcf85363->hiz_output = PCF85363_HIZ_SLEEP;
+ } else if (!strcmp(hiz_output, "disabled")) {
+ pcf85363->hiz_output = PCF85363_HIZ_OFF;
+ } else {
+ dev_warn(&client->dev, "Unknown hiz-output: %s. Assuming disabled",
+ hiz_output);
+ pcf85363->hiz_output = PCF85363_HIZ_OFF;
+ }
+ } else {
+ pcf85363->hiz_output = PCF85363_HIZ_OFF;
+ }
wakeup_source = device_property_read_bool(&client->dev,
"wakeup-source");
- if (client->irq > 0 || wakeup_source) {
+ if (pcf85363->hiz_output != PCF85363_HIZ_OFF) {
+ regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
+ PIN_IO_INTAPM, PIN_IO_INTA_HIZ);
+ } else if (client->irq > 0 || wakeup_source) {
regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
PIN_IO_INTAPM, PIN_IO_INTA_OUT);
@@ -474,6 +506,31 @@ static int pcf85363_probe(struct i2c_client *client)
return ret;
}
+#ifdef CONFIG_PM_SLEEP
+static int pcf85363_suspend(struct device *dev)
+{
+ struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+
+ if (pcf85363->hiz_output == PCF85363_HIZ_SLEEP)
+ regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO, PIN_IO_INTAPM,
+ device_may_wakeup(dev) ? PIN_IO_INTA_OUT :
+ PIN_IO_INTA_CLK);
+
+ return 0;
+}
+
+static int pcf85363_resume(struct device *dev)
+{
+ struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+
+ if (pcf85363->hiz_output == PCF85363_HIZ_SLEEP)
+ regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
+ PIN_IO_INTAPM, PIN_IO_INTA_HIZ);
+
+ return 0;
+}
+#endif
+
static const __maybe_unused struct of_device_id dev_ids[] = {
{ .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
{ .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
@@ -481,9 +538,12 @@ static const __maybe_unused struct of_device_id dev_ids[] = {
};
MODULE_DEVICE_TABLE(of, dev_ids);
+static SIMPLE_DEV_PM_OPS(pcf85363_pm_ops, pcf85363_suspend, pcf85363_resume);
+
static struct i2c_driver pcf85363_driver = {
.driver = {
.name = "pcf85363",
+ .pm = &pcf85363_pm_ops,
.of_match_table = of_match_ptr(dev_ids),
},
.probe = pcf85363_probe,
--
2.39.2
