regulator: Add TPS65185 driver

Add a driver for the TPS65185 regulator. Implement handling of the various
gpio pins. Because the PWRUP (=enable) pin functionality can be achieved
by just using two bits instead, just ensure that it is set to a stable
value.
Implement the pair of symmetric LDOs as a single regulator because they
share a single voltage set register. As the VCOM regulator sits behind that
machinery, just define that one as a supply.
For simplicity, just add the temperature sensor (depending on external NTC)
directly.

There is a mechanism to measure some kick-back voltage during a defined EPD
operation, to calibrate the VCOM voltage setting and store that
non-volatile in the chip to be the power up default setup. That is not
implemented yet in the driver, but that also means that there is a
non-factory default value in these registers after power-up.

Tested-by: Josua Mayer <josua.mayer@jm0.eu>
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://patch.msgid.link/20260102-tps65185-submit-v3-2-23bda35772f2@kemnade.info
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: akemnade

drivers/regulator/Kconfig

@@ -1690,6 +1690,17 @@ config REGULATOR_TPS65132
 	  This driver supports TPS65132 single inductor - dual output
 	  power supply specifically designed for display panels.
 
+config REGULATOR_TPS65185
+	tristate "TI TPS65185 EPD regulator"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  This driver supports the TPS65185 voltage regulator chip
+	  which is used to provide power to Electronic Paper Displays
+	  so it is found in E-Book readers.
+	  If HWWON is enabled, it also provides temperature measurement.
+
+
 config REGULATOR_TPS65217
 	tristate "TI TPS65217 Power regulators"
 	depends on MFD_TPS65217

drivers/regulator/Makefile

@@ -192,6 +192,7 @@ obj-$(CONFIG_REGULATOR_TPS65023) += tps65023-regulator.o
 obj-$(CONFIG_REGULATOR_TPS6507X) += tps6507x-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65086) += tps65086-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65090) += tps65090-regulator.o
+obj-$(CONFIG_REGULATOR_TPS65185) += tps65185.o
 obj-$(CONFIG_REGULATOR_TPS65217) += tps65217-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65218) += tps65218-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65219) += tps65219-regulator.o