Based on kernel version 3.9. Page generated on 2013-05-02 23:00 EST.
1 Samsung GPIO and Pin Mux/Config controller 2 3 Samsung's ARM based SoC's integrates a GPIO and Pin mux/config hardware 4 controller. It controls the input/output settings on the available pads/pins 5 and also provides ability to multiplex and configure the output of various 6 on-chip controllers onto these pads. 7 8 Required Properties: 9 - compatible: should be one of the following. 10 - "samsung,exynos4210-pinctrl": for Exynos4210 compatible pin-controller. 11 - "samsung,exynos4x12-pinctrl": for Exynos4x12 compatible pin-controller. 12 - "samsung,exynos5250-pinctrl": for Exynos5250 compatible pin-controller. 13 14 - reg: Base address of the pin controller hardware module and length of 15 the address space it occupies. 16 17 - Pin banks as child nodes: Pin banks of the controller are represented by child 18 nodes of the controller node. Bank name is taken from name of the node. Each 19 bank node must contain following properties: 20 21 - gpio-controller: identifies the node as a gpio controller and pin bank. 22 - #gpio-cells: number of cells in GPIO specifier. Since the generic GPIO 23 binding is used, the amount of cells must be specified as 2. See generic 24 GPIO binding documentation for description of particular cells. 25 26 - Pin mux/config groups as child nodes: The pin mux (selecting pin function 27 mode) and pin config (pull up/down, driver strength) settings are represented 28 as child nodes of the pin-controller node. There should be atleast one 29 child node and there is no limit on the count of these child nodes. 30 31 The child node should contain a list of pin(s) on which a particular pin 32 function selection or pin configuration (or both) have to applied. This 33 list of pins is specified using the property name "samsung,pins". There 34 should be atleast one pin specfied for this property and there is no upper 35 limit on the count of pins that can be specified. The pins are specified 36 using pin names which are derived from the hardware manual of the SoC. As 37 an example, the pins in GPA0 bank of the pin controller can be represented 38 as "gpa0-0", "gpa0-1", "gpa0-2" and so on. The names should be in lower case. 39 The format of the pin names should be (as per the hardware manual) 40 "[pin bank name]-[pin number within the bank]". 41 42 The pin function selection that should be applied on the pins listed in the 43 child node is specified using the "samsung,pin-function" property. The value 44 of this property that should be applied to each of the pins listed in the 45 "samsung,pins" property should be picked from the hardware manual of the SoC 46 for the specified pin group. This property is optional in the child node if 47 no specific function selection is desired for the pins listed in the child 48 node. The value of this property is used as-is to program the pin-controller 49 function selector register of the pin-bank. 50 51 The child node can also optionally specify one or more of the pin 52 configuration that should be applied on all the pins listed in the 53 "samsung,pins" property of the child node. The following pin configuration 54 properties are supported. 55 56 - samsung,pin-pud: Pull up/down configuration. 57 - samsung,pin-drv: Drive strength configuration. 58 - samsung,pin-pud-pdn: Pull up/down configuration in power down mode. 59 - samsung,pin-drv-pdn: Drive strength configuration in power down mode. 60 61 The values specified by these config properties should be derived from the 62 hardware manual and these values are programmed as-is into the pin 63 pull up/down and driver strength register of the pin-controller. 64 65 Note: A child should include atleast a pin function selection property or 66 pin configuration property (one or more) or both. 67 68 The client nodes that require a particular pin function selection and/or 69 pin configuration should use the bindings listed in the "pinctrl-bindings.txt" 70 file. 71 72 External GPIO and Wakeup Interrupts: 73 74 The controller supports two types of external interrupts over gpio. The first 75 is the external gpio interrupt and second is the external wakeup interrupts. 76 The difference between the two is that the external wakeup interrupts can be 77 used as system wakeup events. 78 79 A. External GPIO Interrupts: For supporting external gpio interrupts, the 80 following properties should be specified in the pin-controller device node. 81 82 - interrupt-parent: phandle of the interrupt parent to which the external 83 GPIO interrupts are forwarded to. 84 - interrupts: interrupt specifier for the controller. The format and value of 85 the interrupt specifier depends on the interrupt parent for the controller. 86 87 In addition, following properties must be present in node of every bank 88 of pins supporting GPIO interrupts: 89 90 - interrupt-controller: identifies the controller node as interrupt-parent. 91 - #interrupt-cells: the value of this property should be 2. 92 - First Cell: represents the external gpio interrupt number local to the 93 external gpio interrupt space of the controller. 94 - Second Cell: flags to identify the type of the interrupt 95 - 1 = rising edge triggered 96 - 2 = falling edge triggered 97 - 3 = rising and falling edge triggered 98 - 4 = high level triggered 99 - 8 = low level triggered 100 101 B. External Wakeup Interrupts: For supporting external wakeup interrupts, a 102 child node representing the external wakeup interrupt controller should be 103 included in the pin-controller device node. This child node should include 104 the following properties. 105 106 - compatible: identifies the type of the external wakeup interrupt controller 107 The possible values are: 108 - samsung,exynos4210-wakeup-eint: represents wakeup interrupt controller 109 found on Samsung Exynos4210 SoC. 110 - interrupt-parent: phandle of the interrupt parent to which the external 111 wakeup interrupts are forwarded to. 112 - interrupts: interrupt used by multiplexed wakeup interrupts. 113 114 In addition, following properties must be present in node of every bank 115 of pins supporting wake-up interrupts: 116 117 - interrupt-controller: identifies the node as interrupt-parent. 118 - #interrupt-cells: the value of this property should be 2 119 - First Cell: represents the external wakeup interrupt number local to 120 the external wakeup interrupt space of the controller. 121 - Second Cell: flags to identify the type of the interrupt 122 - 1 = rising edge triggered 123 - 2 = falling edge triggered 124 - 3 = rising and falling edge triggered 125 - 4 = high level triggered 126 - 8 = low level triggered 127 128 Node of every bank of pins supporting direct wake-up interrupts (without 129 multiplexing) must contain following properties: 130 131 - interrupt-parent: phandle of the interrupt parent to which the external 132 wakeup interrupts are forwarded to. 133 - interrupts: interrupts of the interrupt parent which are used for external 134 wakeup interrupts from pins of the bank, must contain interrupts for all 135 pins of the bank. 136 137 Aliases: 138 139 All the pin controller nodes should be represented in the aliases node using 140 the following format 'pinctrl{n}' where n is a unique number for the alias. 141 142 Example: A pin-controller node with pin banks: 143 144 pinctrl_0: pinctrl@11400000 { 145 compatible = "samsung,exynos4210-pinctrl"; 146 reg = <0x11400000 0x1000>; 147 interrupts = <0 47 0>; 148 149 /* ... */ 150 151 /* Pin bank without external interrupts */ 152 gpy0: gpy0 { 153 gpio-controller; 154 #gpio-cells = <2>; 155 }; 156 157 /* ... */ 158 159 /* Pin bank with external GPIO or muxed wake-up interrupts */ 160 gpj0: gpj0 { 161 gpio-controller; 162 #gpio-cells = <2>; 163 164 interrupt-controller; 165 #interrupt-cells = <2>; 166 }; 167 168 /* ... */ 169 170 /* Pin bank with external direct wake-up interrupts */ 171 gpx0: gpx0 { 172 gpio-controller; 173 #gpio-cells = <2>; 174 175 interrupt-controller; 176 interrupt-parent = <&gic>; 177 interrupts = <0 16 0>, <0 17 0>, <0 18 0>, <0 19 0>, 178 <0 20 0>, <0 21 0>, <0 22 0>, <0 23 0>; 179 #interrupt-cells = <2>; 180 }; 181 182 /* ... */ 183 }; 184 185 Example 1: A pin-controller node with pin groups. 186 187 pinctrl_0: pinctrl@11400000 { 188 compatible = "samsung,exynos4210-pinctrl"; 189 reg = <0x11400000 0x1000>; 190 interrupts = <0 47 0>; 191 192 /* ... */ 193 194 uart0_data: uart0-data { 195 samsung,pins = "gpa0-0", "gpa0-1"; 196 samsung,pin-function = <2>; 197 samsung,pin-pud = <0>; 198 samsung,pin-drv = <0>; 199 }; 200 201 uart0_fctl: uart0-fctl { 202 samsung,pins = "gpa0-2", "gpa0-3"; 203 samsung,pin-function = <2>; 204 samsung,pin-pud = <0>; 205 samsung,pin-drv = <0>; 206 }; 207 208 uart1_data: uart1-data { 209 samsung,pins = "gpa0-4", "gpa0-5"; 210 samsung,pin-function = <2>; 211 samsung,pin-pud = <0>; 212 samsung,pin-drv = <0>; 213 }; 214 215 uart1_fctl: uart1-fctl { 216 samsung,pins = "gpa0-6", "gpa0-7"; 217 samsung,pin-function = <2>; 218 samsung,pin-pud = <0>; 219 samsung,pin-drv = <0>; 220 }; 221 222 i2c2_bus: i2c2-bus { 223 samsung,pins = "gpa0-6", "gpa0-7"; 224 samsung,pin-function = <3>; 225 samsung,pin-pud = <3>; 226 samsung,pin-drv = <0>; 227 }; 228 }; 229 230 Example 2: A pin-controller node with external wakeup interrupt controller node. 231 232 pinctrl_1: pinctrl@11000000 { 233 compatible = "samsung,exynos4210-pinctrl"; 234 reg = <0x11000000 0x1000>; 235 interrupts = <0 46 0> 236 237 /* ... */ 238 239 wakeup-interrupt-controller { 240 compatible = "samsung,exynos4210-wakeup-eint"; 241 interrupt-parent = <&gic>; 242 interrupts = <0 32 0>; 243 }; 244 }; 245 246 Example 3: A uart client node that supports 'default' and 'flow-control' states. 247 248 uart@13800000 { 249 compatible = "samsung,exynos4210-uart"; 250 reg = <0x13800000 0x100>; 251 interrupts = <0 52 0>; 252 pinctrl-names = "default", "flow-control; 253 pinctrl-0 = <&uart0_data>; 254 pinctrl-1 = <&uart0_data &uart0_fctl>; 255 }; 256 257 Example 4: Set up the default pin state for uart controller. 258 259 static int s3c24xx_serial_probe(struct platform_device *pdev) { 260 struct pinctrl *pinctrl; 261 262 /* ... */ 263 264 pinctrl = devm_pinctrl_get_select_default(&pdev->dev); 265 }