1 * Freescale MXS Pin Controller
2
3 The pins controlled by mxs pin controller are
4 has 32 pins. Each pin has 4 multiplexing func
5 function is GPIO. The configuration on the pi
6 voltage and pull-up.
7
8 Required properties:
9 - compatible: "fsl,imx23-pinctrl" or "fsl,imx2
10 - reg: Should contain the register physical ad
11 pin controller.
12
13 Please refer to pinctrl-bindings.txt in this d
14 common pinctrl bindings used by client devices
15
16 The node of mxs pin controller acts as a conta
17 subnodes. Each of these subnodes represents s
18 a group of pins, and only affects those parame
19 In other words, a subnode that describes a dri
20 information about pull-up. For this reason, ev
21 actually tristates in this binding: unspecifie
22 represented as an absent property, and off/on
23 values 0 and 1.
24
25 Those subnodes under mxs pin controller node w
26 One is to set up a group of pins for a functio
27 configurations, and it's called group node in
28 one is to adjust the pin configuration for som
29 different configuration than what is defined i
30 document calls this type of node config node.
31
32 On mxs, there is no hardware pin group. The pi
33 means a group of pins put together for particu
34 particular function, like SSP0 functioning as
35 group node should include all the pins needed
36 having these pins defined in several group nod
37 "pinctrl-*" phandle in client device node shou
38 pointed in there, while the phandle can have m
39 there to adjust configurations for some pins i
40
41 Required subnode-properties:
42 - fsl,pinmux-ids: An integer array. Each inte
43 with given mux function, with bank, pin and
44
45 [15..12] : bank number
46 [11..4] : pin number
47 [3..0] : mux selection
48
49 This integer with mux selection packed is us
50 and config nodes to identify a pin. The mux
51 effects only on group node, and will get ign
52 since config node is only meant to set up pi
53
54 Valid values for these integers are listed b
55
56 - reg: Should be the index of the group nodes
57 is required only for group nodes, and should
58 nodes.
59
60 Optional subnode-properties:
61 - fsl,drive-strength: Integer.
62 0: MXS_DRIVE_4mA
63 1: MXS_DRIVE_8mA
64 2: MXS_DRIVE_12mA
65 3: MXS_DRIVE_16mA
66 - fsl,voltage: Integer.
67 0: MXS_VOLTAGE_LOW - 1.8 V
68 1: MXS_VOLTAGE_HIGH - 3.3 V
69 - fsl,pull-up: Integer.
70 0: MXS_PULL_DISABLE - Disable the internal
71 1: MXS_PULL_ENABLE - Enable the internal
72
73 Note that when enabling the pull-up, the inter
74 Also, some pins doesn't have a pull up, in tha
75 will only disable the internal pad keeper.
76
77 Examples:
78
79 pinctrl@80018000 {
80 #address-cells = <1>;
81 #size-cells = <0>;
82 compatible = "fsl,imx28-pinctrl";
83 reg = <0x80018000 2000>;
84
85 mmc0_8bit_pins_a: mmc0-8bit@0 {
86 reg = <0>;
87 fsl,pinmux-ids = <
88 MX28_PAD_SSP0_DATA0__S
89 MX28_PAD_SSP0_DATA1__S
90 MX28_PAD_SSP0_DATA2__S
91 MX28_PAD_SSP0_DATA3__S
92 MX28_PAD_SSP0_DATA4__S
93 MX28_PAD_SSP0_DATA5__S
94 MX28_PAD_SSP0_DATA6__S
95 MX28_PAD_SSP0_DATA7__S
96 MX28_PAD_SSP0_CMD__SSP
97 MX28_PAD_SSP0_DETECT__
98 MX28_PAD_SSP0_SCK__SSP
99 >;
100 fsl,drive-strength = <MXS_DRIV
101 fsl,voltage = <MXS_VOLTAGE_HIG
102 fsl,pull-up = <MXS_PULL_ENABLE
103 };
104
105 mmc_cd_cfg: mmc-cd-cfg {
106 fsl,pinmux-ids = <MX28_PAD_SSP
107 fsl,pull-up = <MXS_PULL_DISABL
108 };
109
110 mmc_sck_cfg: mmc-sck-cfg {
111 fsl,pinmux-ids = <MX28_PAD_SSP
112 fsl,drive-strength = <MXS_DRIV
113 fsl,pull-up = <MXS_PULL_DISABL
114 };
115 };
116
117 In this example, group node mmc0-8bit defines
118 to function as a 8-bit mmc device, with 8mA, 3
119 applied on all these pins. And config nodes m
120 adjusting the configuration for pins card-dete
121 node mmc0-8bit defines. Only the configuratio
122 to be listed in the config nodes.
123
124 Valid values for i.MX28/i.MX23 pinmux-id are d
125 arch/arm/boot/dts/imx28-pinfunc.h and arch/arm
126 The definitions for the padconfig properties c
127 arch/arm/boot/dts/mxs-pinfunc.h.
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