ARM: dts: Enable PWM backlight on rk3288-evb

PWM0 is the PWM associated with the LCD backlight.  Enable it.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288-evb.dtsi

@@ -10,6 +10,7 @@
  * GNU General Public License for more details.
  */
 
+#include <dt-bindings/pwm/pwm.h>
 #include "rk3288.dtsi"
 
 / {
@@ -17,6 +18,48 @@ memory {
 		reg = <0x0 0x80000000>;
 	};
 
+	backlight {
+		compatible = "pwm-backlight";
+		brightness-levels = <
+			  0   1   2   3   4   5   6   7
+			  8   9  10  11  12  13  14  15
+			 16  17  18  19  20  21  22  23
+			 24  25  26  27  28  29  30  31
+			 32  33  34  35  36  37  38  39
+			 40  41  42  43  44  45  46  47
+			 48  49  50  51  52  53  54  55
+			 56  57  58  59  60  61  62  63
+			 64  65  66  67  68  69  70  71
+			 72  73  74  75  76  77  78  79
+			 80  81  82  83  84  85  86  87
+			 88  89  90  91  92  93  94  95
+			 96  97  98  99 100 101 102 103
+			104 105 106 107 108 109 110 111
+			112 113 114 115 116 117 118 119
+			120 121 122 123 124 125 126 127
+			128 129 130 131 132 133 134 135
+			136 137 138 139 140 141 142 143
+			144 145 146 147 148 149 150 151
+			152 153 154 155 156 157 158 159
+			160 161 162 163 164 165 166 167
+			168 169 170 171 172 173 174 175
+			176 177 178 179 180 181 182 183
+			184 185 186 187 188 189 190 191
+			192 193 194 195 196 197 198 199
+			200 201 202 203 204 205 206 207
+			208 209 210 211 212 213 214 215
+			216 217 218 219 220 221 222 223
+			224 225 226 227 228 229 230 231
+			232 233 234 235 236 237 238 239
+			240 241 242 243 244 245 246 247
+			248 249 250 251 252 253 254 255>;
+		default-brightness-level = <128>;
+		enable-gpios = <&gpio7 2 GPIO_ACTIVE_HIGH>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en>;
+		pwms = <&pwm0 0 1000000 PWM_POLARITY_INVERTED>;
+	};
+
 	gpio-keys {
 		compatible = "gpio-keys";
 		#address-cells = <1>;
@@ -81,6 +124,10 @@ &wdt {
 	status = "okay";
 };
 
+&pwm0 {
+	status = "okay";
+};
+
 &uart0 {
 	status = "okay";
 };
@@ -102,6 +149,12 @@ &uart4 {
 };
 
 &pinctrl {
+	backlight {
+		bl_en: bl-en {
+			rockchip,pins = <7 2 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+
 	buttons {
 		pwrbtn: pwrbtn {
 			rockchip,pins = <0 5 RK_FUNC_GPIO &pcfg_pull_up>;