mfd: ab8500: Augment DT bindings

As we migrate the AB8500 GPADC driver to use IIO, we need to augment
the bindings to account for defining the ADC channels in the device
tree.

Cc: devicetree@vger.kernel.org
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/mfd/ab8500.txt

@@ -69,6 +69,18 @@ Required child device properties:
 - compatible             : "stericsson,ab8500-[bm|btemp|charger|fg|gpadc|gpio|ponkey|
                                                pwm|regulator|rtc|sysctrl|usb]";
 
+  A few child devices require ADC channels from the GPADC node. Those follow the
+  standard bindings from iio/iio-bindings.txt and iio/adc/adc.txt
+
+  abx500-temp		 : io-channels "aux1" and "aux2" for measuring external
+			   temperatures.
+  ab8500-fg		 : io-channel "main_bat_v" for measuring main battery voltage,
+  ab8500-btemp		 : io-channels "btemp_ball" and "bat_ctrl" for measuring the
+			   battery voltage.
+  ab8500-charger	 : io-channels "main_charger_v", "main_charger_c", "vbus_v",
+			   "usb_charger_c" for measuring voltage and current of the
+			   different charging supplies.
+
 Optional child device properties:
 - interrupts             : contains the device IRQ(s) using the 2-cell format (see above)
 - interrupt-names        : contains names of IRQ resource in the order in which they were
@@ -102,8 +114,115 @@ ab8500 {
                               39 0x4>;
                 interrupt-names = "HW_CONV_END", "SW_CONV_END";
                 vddadc-supply = <&ab8500_ldo_tvout_reg>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		#io-channel-cells = <1>;
+
+		/* GPADC channels */
+		bat_ctrl: channel@1 {
+			reg = <0x01>;
+		};
+		btemp_ball: channel@2 {
+			reg = <0x02>;
+		};
+		main_charger_v: channel@3 {
+			reg = <0x03>;
+		};
+		acc_detect1: channel@4 {
+			reg = <0x04>;
+		};
+		acc_detect2: channel@5 {
+			reg = <0x05>;
+		};
+		adc_aux1: channel@6 {
+			reg = <0x06>;
+		};
+		adc_aux2: channel@7 {
+			reg = <0x07>;
+		};
+		main_batt_v: channel@8 {
+			reg = <0x08>;
+		};
+		vbus_v: channel@9 {
+			reg = <0x09>;
+		};
+		main_charger_c: channel@a {
+			reg = <0x0a>;
+		};
+		usb_charger_c: channel@b {
+			reg = <0x0b>;
+		};
+		bk_bat_v: channel@c {
+			reg = <0x0c>;
+		};
+		die_temp: channel@d {
+			reg = <0x0d>;
+		};
+		usb_id: channel@e {
+			reg = <0x0e>;
+		};
+		xtal_temp: channel@12 {
+			reg = <0x12>;
+		};
+		vbat_true_meas: channel@13 {
+			reg = <0x13>;
+		};
+		bat_ctrl_and_ibat: channel@1c {
+			reg = <0x1c>;
+		};
+		vbat_meas_and_ibat: channel@1d {
+			reg = <0x1d>;
+		};
+		vbat_true_meas_and_ibat: channel@1e {
+			reg = <0x1e>;
+		};
+		bat_temp_and_ibat: channel@1f {
+			reg = <0x1f>;
+		};
         };
 
+	ab8500_temp {
+		compatible = "stericsson,abx500-temp";
+		io-channels = <&gpadc 0x06>,
+			      <&gpadc 0x07>;
+		io-channel-name = "aux1", "aux2";
+	};
+
+	ab8500_battery: ab8500_battery {
+		stericsson,battery-type = "LIPO";
+		thermistor-on-batctrl;
+	};
+
+	ab8500_fg {
+		compatible = "stericsson,ab8500-fg";
+		battery	   = <&ab8500_battery>;
+		io-channels = <&gpadc 0x08>;
+		io-channel-name = "main_bat_v";
+	};
+
+	ab8500_btemp {
+		compatible = "stericsson,ab8500-btemp";
+		battery	   = <&ab8500_battery>;
+		io-channels = <&gpadc 0x02>,
+			      <&gpadc 0x01>;
+		io-channel-name = "btemp_ball",
+				"bat_ctrl";
+	};
+
+	ab8500_charger {
+		compatible	= "stericsson,ab8500-charger";
+		battery		= <&ab8500_battery>;
+		vddadc-supply	= <&ab8500_ldo_tvout_reg>;
+		io-channels = <&gpadc 0x03>,
+			      <&gpadc 0x0a>,
+			      <&gpadc 0x09>,
+			      <&gpadc 0x0b>;
+		io-channel-name = "main_charger_v",
+				"main_charger_c",
+				"vbus_v",
+				"usb_charger_c";
+	};
+
         ab8500-usb {
                 compatible = "stericsson,ab8500-usb";
                 interrupts = < 90 0x4