mfd: Support configurable numbers of DCDCs and ISINKs on WM8350

Some WM8350 variants have fewer DCDCs and ISINKs. Identify these at
probe and refuse to use the absent DCDCs when running on these chips.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

drivers/mfd/wm8350-core.c

@@ -1301,6 +1301,9 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
 
 	switch (mask_rev) {
 	case 0:
+		wm8350->pmic.max_dcdc = WM8350_DCDC_6;
+		wm8350->pmic.max_isink = WM8350_ISINK_B;
+
 		switch (chip_rev) {
 		case WM8350_REV_E:
 			dev_info(wm8350->dev, "WM8350 Rev E\n");
@@ -1325,6 +1328,9 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
 		break;
 
 	case 2:
+		wm8350->pmic.max_dcdc = WM8350_DCDC_6;
+		wm8350->pmic.max_isink = WM8350_ISINK_B;
+
 		switch (chip_rev) {
 		case 0:
 			dev_info(wm8350->dev, "WM8352 Rev A\n");

drivers/regulator/wm8350-regulator.c

@@ -1380,6 +1380,13 @@ int wm8350_register_regulator(struct wm8350 *wm8350, int reg,
 	if (wm8350->pmic.pdev[reg])
 		return -EBUSY;
 
+	if (reg >= WM8350_DCDC_1 && reg <= WM8350_DCDC_6 &&
+	    reg > wm8350->pmic.max_dcdc)
+		return -ENODEV;
+	if (reg >= WM8350_ISINK_A && reg <= WM8350_ISINK_B &&
+	    reg > wm8350->pmic.max_isink)
+		return -ENODEV;
+
 	pdev = platform_device_alloc("wm8350-regulator", reg);
 	if (!pdev)
 		return -ENOMEM;

include/linux/mfd/wm8350/pmic.h

@@ -701,6 +701,10 @@ struct platform_device;
 struct regulator_init_data;
 
 struct wm8350_pmic {
+	/* Number of regulators of each type on this device */
+	int max_dcdc;
+	int max_isink;
+
 	/* ISINK to DCDC mapping */
 	int isink_A_dcdc;
 	int isink_B_dcdc;