regulator: tps65218: do not disable DCDC3 during poweroff on broken PMICs

Some versions of tps65218 do not seem to support poweroff modes properly
if DCDC3 regulator is shut-down. Thus, keep it enabled even during
poweroff if the version info matches the broken silicon revision.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/tps65218-regulator.c

@@ -180,6 +180,14 @@ static int tps65218_pmic_set_suspend_disable(struct regulator_dev *dev)
 	if (rid < TPS65218_DCDC_1 || rid > TPS65218_LDO_1)
 		return -EINVAL;
 
+	/*
+	 * Certain revisions of TPS65218 will need to have DCDC3 regulator
+	 * enabled always, otherwise an immediate system reboot will occur
+	 * during poweroff.
+	 */
+	if (rid == TPS65218_DCDC_3 && tps->rev == TPS65218_REV_2_1)
+		return 0;
+
 	if (!tps->info[rid]->strobe) {
 		if (rid == TPS65218_DCDC_3)
 			tps->info[rid]->strobe = 3;

include/linux/mfd/tps65218.h

@@ -63,6 +63,11 @@
 #define TPS65218_CHIPID_CHIP_MASK	0xF8
 #define TPS65218_CHIPID_REV_MASK	0x07
 
+#define TPS65218_REV_1_0		0x0
+#define TPS65218_REV_1_1		0x1
+#define TPS65218_REV_2_0		0x2
+#define TPS65218_REV_2_1		0x3
+
 #define TPS65218_INT1_VPRG		BIT(5)
 #define TPS65218_INT1_AC		BIT(4)
 #define TPS65218_INT1_PB		BIT(3)