1 *ST pin controller.
2
3 Each multi-function pin is controlled, driven and routed through the
4 PIO multiplexing block. Each pin supports GPIO functionality (ALT0)
5 and multiple alternate functions(ALT1 - ALTx) that directly connect
6 the pin to different hardware blocks.
7
8 When a pin is in GPIO mode, Output Enable (OE), Open Drain(OD), and
9 Pull Up (PU) are driven by the related PIO block.
10
11 ST pinctrl driver controls PIO multiplexing block and also interacts with
12 gpio driver to configure a pin.
13
14 GPIO bank can have one of the two possible types of interrupt-wirings.
15
16 First type is via irqmux, single interrupt is used by multiple gpio banks. This
17 reduces number of overall interrupts numbers required. All these banks belong to
18 a single pincontroller.
19 _________
20 | |----> [gpio-bank (n) ]
21 | |----> [gpio-bank (n + 1)]
22 [irqN]-- | irq-mux |----> [gpio-bank (n + 2)]
23 | |----> [gpio-bank (... )]
24 |_________|----> [gpio-bank (n + 7)]
25
26 Second type has a dedicated interrupt per gpio bank.
27
28 [irqN]----> [gpio-bank (n)]
29
30
31 Pin controller node:
32 Required properties:
33 - compatible : should be "st,stih407-<pio-block>-pinctrl"
34 - st,syscfg : Should be a phandle of the syscfg node.
35 - st,retime-pin-mask : Should be mask to specify which pins can be retimed.
36 If the property is not present, it is assumed that all the pins in the
37 bank are capable of retiming. Retiming is mainly used to improve the
38 IO timing margins of external synchronous interfaces.
39 - ranges : defines mapping between pin controller node (parent) to gpio-bank
40 node (children).
41
42 Optional properties:
43 - interrupts : Interrupt number of the irqmux. If the interrupt is shared
44 with other gpio banks via irqmux.
45 a irqline and gpio banks.
46 - reg : irqmux memory resource. If irqmux is present.
47 - reg-names : irqmux resource should be named as "irqmux".
48
49 GPIO controller/bank node.
50 Required properties:
51 - gpio-controller : Indicates this device is a GPIO controller
52 - #gpio-cells : Must be two.
53 - First cell: specifies the pin number inside the controller
54 - Second cell: specifies whether the pin is logically inverted.
55 - 0 = active high
56 - 1 = active low
57 - st,bank-name : Should be a name string for this bank as specified in
58 datasheet.
59
60 Optional properties:
61 - interrupts : Interrupt number for this gpio bank. If there is a dedicated
62 interrupt wired up for this gpio bank.
63
64 - interrupt-controller : Indicates this device is a interrupt controller. GPIO
65 bank can be an interrupt controller iff one of the interrupt type either via
66 irqmux or a dedicated interrupt per bank is specified.
67
68 - #interrupt-cells: the value of this property should be 2.
69 - First Cell: represents the external gpio interrupt number local to the
70 gpio interrupt space of the controller.
71 - Second Cell: flags to identify the type of the interrupt
72 - 1 = rising edge triggered
73 - 2 = falling edge triggered
74 - 3 = rising and falling edge triggered
75 - 4 = high level triggered
76 - 8 = low level triggered
77 for related macros look in:
78 include/dt-bindings/interrupt-controller/irq.h
79
80 Example:
81 pin-controller-sbc {
82 #address-cells = <1>;
83 #size-cells = <1>;
84 compatible = "st,stih407-sbc-pinctrl";
85 st,syscfg = <&syscfg_sbc>;
86 reg = <0x0961f080 0x4>;
87 reg-names = "irqmux";
88 interrupts = <GIC_SPI 188 IRQ_TYPE_NONE>;
89 interrupt-names = "irqmux";
90 ranges = <0 0x09610000 0x6000>;
91
92 pio0: gpio@9610000 {
93 gpio-controller;
94 #gpio-cells = <2>;
95 interrupt-controller;
96 #interrupt-cells = <2>;
97 reg = <0x0 0x100>;
98 st,bank-name = "PIO0";
99 };
100 ...
101 pin-functions nodes follow...
102 };
103
104
105 Contents of function subnode node:
106 ----------------------
107 Required properties for pin configuration node:
108 - st,pins : Child node with list of pins with configuration.
109
110 Below is the format of how each pin conf should look like.
111
112 <bank offset mux mode rt_type rt_delay rt_clk>
113
114 Every PIO is represented with 4-7 parameters depending on retime configuration.
115 Each parameter is explained as below.
116
117 -bank : Should be bank phandle to which this PIO belongs.
118 -offset : Offset in the PIO bank.
119 -mux : Should be alternate function number associated this pin.
120 Use same numbers from datasheet.
121 -mode :pin configuration is selected from one of the below values.
122 IN
123 IN_PU
124 OUT
125 BIDIR
126 BIDIR_PU
127
128 -rt_type Retiming Configuration for the pin.
129 Possible retime configuration are:
130
131 ------- -------------
132 value args
133 ------- -------------
134 NICLK <delay> <clk>
135 ICLK_IO <delay> <clk>
136 BYPASS <delay>
137 DE_IO <delay> <clk>
138 SE_ICLK_IO <delay> <clk>
139 SE_NICLK_IO <delay> <clk>
140
141 - delay is retime delay in pico seconds as mentioned in data sheet.
142
143 - rt_clk :clk to be use for retime.
144 Possible values are:
145 CLK_A
146 CLK_B
147 CLK_C
148 CLK_D
149
150 Example of mmcclk pin which is a bi-direction pull pu with retime config
151 as non inverted clock retimed with CLK_B and delay of 0 pico seconds:
152
153 pin-controller {
154 ...
155 mmc0 {
156 pinctrl_mmc: mmc {
157 st,pins {
158 mmcclk = <&PIO13 4 ALT4 BIDIR_PU NICLK 0 CLK_B>;
159 ...
160 };
161 };
162 ...
163 };
164 };
165
166 sdhci0:sdhci@fe810000{
167 ...
168 interrupt-parent = <&pio3>;
169 #interrupt-cells = <2>;
170 interrupts = <3 IRQ_TYPE_LEVEL_HIGH>; /* Interrupt line via PIO3-3 */
171 interrupt-names = "card-detect";
172 pinctrl-names = "default";
173 pinctrl-0 = <&pinctrl_mmc>;
174 };
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