[PATCH] regulator: fan53555: Add support for FAN53555BUC23X type

[Arash Golgol]

FAN53555BUC23X has the ID 0 and REV 0xc, starts at 600mV and
increments in 12.5mV steps.

Per the datasheet, the FAN53555BUC23X (23 option) is grouped with
the 00 and 13 options for soft-start timing (t_SS = 300us typ.),
so the existing enable_time = 400 is reused here as well.

This variant is found on the ASUS Tinker Edge R (RK3399Pro) as the
supply regulator for both vdd_gpu and vdd_cpu_b. Verified across
the full GPU OPP table with the userspace devfreq governor.

Signed-off-by: Arash Golgol <arash.golgol@xxxxxxxxx>
---
 drivers/regulator/fan53555.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/regulator/fan53555.c b/drivers/regulator/fan53555.c
index c282236959b1..59155cad99bc 100644
--- a/drivers/regulator/fan53555.c
+++ b/drivers/regulator/fan53555.c
@@ -113,6 +113,7 @@ enum {
 enum {
 	FAN53555_CHIP_REV_00 = 0x3,
 	FAN53555_CHIP_REV_13 = 0xf,
+	FAN53555_CHIP_REV_23 = 0xc,
 };
 
 enum {
@@ -305,6 +306,11 @@ static int fan53555_voltages_setup_fairchild(struct fan53555_device_info *di)
 			di->vsel_step = 10000;
 			di->enable_time = 400;
 			break;
+		case FAN53555_CHIP_REV_23:
+			di->vsel_min = 600000;
+			di->vsel_step = 12500;
+			di->enable_time = 400;
+			break;
 		default:
 			dev_err(di->dev,
 				"Chip ID %d with rev %d not supported!\n",
-- 
2.34.1