From 95e83d98e10438bd76baaab029097ba54e3ea71b Mon Sep 17 00:00:00 2001 From: Heiko Schocher Date: Tue, 25 Aug 2026 09:19:18 +0200 Subject: [PATCH] rtc: rs5c372: support eco mode on R2223x The R2223x can run in an eco mode that lowers its current consumption from the backup supply. Follow the ricoh,eco-mode property from the device tree: enable the mode when the property is set, turn it off when it is not set, as the bit is in CTRL2 register, which is backed by the same supply and keeps its contents across a reset, and no other path in the driver touches it. Signed-off-by: Heiko Schocher Link: https://patch.msgid.link/20260825071927.4090460-4-hs@nabladev.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-rs5c372.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c index c65b76cc0dc6..9ab6f2c28f7b 100644 --- a/drivers/rtc/rtc-rs5c372.c +++ b/drivers/rtc/rtc-rs5c372.c @@ -52,6 +52,7 @@ #define RS5C_REG_CTRL2 15 # define RS5C372_CTRL2_24 (1 << 5) # define RS5C_CTRL2_XSTP (1 << 4) /* only if !R2x2x */ +# define R2223x_CTRL2_ECO (1 << 7) /* only if R2223x */ # define R2x2x_CTRL2_VDET (1 << 6) /* only if R2x2x */ # define R2x2x_CTRL2_XSTP (1 << 5) /* only if R2x2x */ # define R2x2x_CTRL2_PON (1 << 4) /* only if R2x2x */ @@ -807,6 +808,24 @@ static int rs5c_oscillator_setup(struct rs5c372 *rs5c372) return 0; } +static int rs5c372_set_eco_mode(struct rs5c372 *rs5c372, bool eco) +{ + struct i2c_client *client = rs5c372->client; + int ctrl2; + + ctrl2 = i2c_smbus_read_byte_data(client, RS5C_ADDR(RS5C_REG_CTRL2)); + if (ctrl2 < 0) + return ctrl2; + + if (eco) + ctrl2 |= R2223x_CTRL2_ECO; + else + ctrl2 &= ~R2223x_CTRL2_ECO; + + return i2c_smbus_write_byte_data(client, RS5C_ADDR(RS5C_REG_CTRL2), + ctrl2); +} + static int rs5c372_probe(struct i2c_client *client) { int err = 0; @@ -903,6 +922,15 @@ static int rs5c372_probe(struct i2c_client *client) rs5c372->time24 ? "24hr" : "am/pm" ); + if (rs5c372->type == rtc_r2223x) { + bool eco = device_property_read_bool(&client->dev, + "ricoh,eco-mode"); + + err = rs5c372_set_eco_mode(rs5c372, eco); + if (err < 0) + goto exit; + } + /* REVISIT use client->irq to register alarm irq ... */ rs5c372->rtc = devm_rtc_device_register(&client->dev, rs5c372_driver.driver.name,