Commit | Line | Data |
---|---|---|
a9c5fff5 DB |
1 | # |
2 | # GPIO infrastructure and expanders | |
3 | # | |
4 | ||
7444a72e | 5 | config ARCH_WANT_OPTIONAL_GPIOLIB |
a9c5fff5 | 6 | bool |
7444a72e MB |
7 | help |
8 | Select this config option from the architecture Kconfig, if | |
9 | it is possible to use gpiolib on the architecture, but let the | |
10 | user decide whether to actually build it or not. | |
11 | Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does | |
12 | not depend on GPIOs being available, but rather let the user | |
13 | decide whether he needs it or not. | |
14 | ||
15 | config ARCH_REQUIRE_GPIOLIB | |
16 | bool | |
17 | select GPIOLIB | |
a9c5fff5 DB |
18 | help |
19 | Platforms select gpiolib if they use this infrastructure | |
20 | for all their GPIOs, usually starting with ones integrated | |
21 | into SOC processors. | |
7444a72e MB |
22 | Selecting this from the architecture code will cause the gpiolib |
23 | code to always get built in. | |
24 | ||
25 | ||
26 | ||
27 | menuconfig GPIOLIB | |
28 | bool "GPIO Support" | |
29 | depends on ARCH_WANT_OPTIONAL_GPIOLIB || ARCH_REQUIRE_GPIOLIB | |
30 | select GENERIC_GPIO | |
31 | help | |
32 | This enables GPIO support through the generic GPIO library. | |
33 | You only need to enable this, if you also want to enable | |
34 | one or more of the GPIO expansion card drivers below. | |
35 | ||
36 | If unsure, say N. | |
a9c5fff5 | 37 | |
7444a72e | 38 | if GPIOLIB |
a9c5fff5 DB |
39 | |
40 | config DEBUG_GPIO | |
41 | bool "Debug GPIO calls" | |
42 | depends on DEBUG_KERNEL | |
43 | help | |
44 | Say Y here to add some extra checks and diagnostics to GPIO calls. | |
45 | The checks help ensure that GPIOs have been properly initialized | |
46 | before they are used and that sleeping calls aren not made from | |
47 | nonsleeping contexts. They can make bitbanged serial protocols | |
48 | slower. The diagnostics help catch the type of setup errors | |
49 | that are most common when setting up new platforms or boards. | |
50 | ||
d8f388d8 DB |
51 | config GPIO_SYSFS |
52 | bool "/sys/class/gpio/... (sysfs interface)" | |
53 | depends on SYSFS && EXPERIMENTAL | |
54 | help | |
55 | Say Y here to add a sysfs interface for GPIOs. | |
56 | ||
57 | This is mostly useful to work around omissions in a system's | |
58 | kernel support. Those are common in custom and semicustom | |
59 | hardware assembled using standard kernels with a minimum of | |
60 | custom patches. In those cases, userspace code may import | |
61 | a given GPIO from the kernel, if no kernel driver requested it. | |
62 | ||
63 | Kernel drivers may also request that a particular GPIO be | |
64 | exported to userspace; this can be useful when debugging. | |
65 | ||
a9c5fff5 DB |
66 | # put expanders in the right section, in alphabetical order |
67 | ||
68 | comment "I2C GPIO expanders:" | |
69 | ||
bbcd6d54 EM |
70 | config GPIO_MAX732X |
71 | tristate "MAX7319, MAX7320-7327 I2C Port Expanders" | |
72 | depends on I2C | |
73 | help | |
74 | Say yes here to support the MAX7319, MAX7320-7327 series of I2C | |
75 | Port Expanders. Each IO port on these chips has a fixed role of | |
76 | Input (designated by 'I'), Push-Pull Output ('O'), or Open-Drain | |
77 | Input and Output (designed by 'P'). The combinations are listed | |
78 | below: | |
79 | ||
80 | 8 bits: max7319 (8I), max7320 (8O), max7321 (8P), | |
81 | max7322 (4I4O), max7323 (4P4O) | |
82 | ||
83 | 16 bits: max7324 (8I8O), max7325 (8P8O), | |
84 | max7326 (4I12O), max7327 (4P12O) | |
85 | ||
86 | Board setup code must specify the model to use, and the start | |
87 | number for these GPIOs. | |
88 | ||
f3dc3630 | 89 | config GPIO_PCA953X |
7059d4b0 | 90 | tristate "PCA953x, PCA955x, and MAX7310 I/O ports" |
9e60fdcf | 91 | depends on I2C |
92 | help | |
7059d4b0 DB |
93 | Say yes here to provide access to several register-oriented |
94 | SMBus I/O expanders, made mostly by NXP or TI. Compatible | |
95 | models include: | |
96 | ||
97 | 4 bits: pca9536, pca9537 | |
98 | ||
99 | 8 bits: max7310, pca9534, pca9538, pca9554, pca9557 | |
100 | ||
101 | 16 bits: pca9535, pca9539, pca9555 | |
9e60fdcf | 102 | |
103 | This driver can also be built as a module. If so, the module | |
f3dc3630 | 104 | will be called pca953x. |
9e60fdcf | 105 | |
15fae37d | 106 | config GPIO_PCF857X |
1673ad52 | 107 | tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders" |
15fae37d DB |
108 | depends on I2C |
109 | help | |
110 | Say yes here to provide access to most "quasi-bidirectional" I2C | |
111 | GPIO expanders used for additional digital outputs or inputs. | |
112 | Most of these parts are from NXP, though TI is a second source for | |
113 | some of them. Compatible models include: | |
114 | ||
115 | 8 bits: pcf8574, pcf8574a, pca8574, pca8574a, | |
1673ad52 DB |
116 | pca9670, pca9672, pca9674, pca9674a, |
117 | max7328, max7329 | |
15fae37d DB |
118 | |
119 | 16 bits: pcf8575, pcf8575c, pca8575, | |
120 | pca9671, pca9673, pca9675 | |
121 | ||
122 | Your board setup code will need to declare the expanders in | |
123 | use, and assign numbers to the GPIOs they expose. Those GPIOs | |
124 | can then be used from drivers and other kernel code, just like | |
125 | other GPIOs, but only accessible from task contexts. | |
126 | ||
127 | This driver provides an in-kernel interface to those GPIOs using | |
128 | platform-neutral GPIO calls. | |
129 | ||
ff1d5c2f MB |
130 | comment "PCI GPIO expanders:" |
131 | ||
132 | config GPIO_BT8XX | |
133 | tristate "BT8XX GPIO abuser" | |
134 | depends on PCI && VIDEO_BT848=n | |
135 | help | |
136 | The BT8xx frame grabber chip has 24 GPIO pins than can be abused | |
137 | as a cheap PCI GPIO card. | |
138 | ||
139 | This chip can be found on Miro, Hauppauge and STB TV-cards. | |
140 | ||
141 | The card needs to be physically altered for using it as a | |
142 | GPIO card. For more information on how to build a GPIO card | |
143 | from a BT8xx TV card, see the documentation file at | |
144 | Documentation/bt8xxgpio.txt | |
145 | ||
146 | If unsure, say N. | |
147 | ||
a9c5fff5 DB |
148 | comment "SPI GPIO expanders:" |
149 | ||
0c36ec31 JB |
150 | config GPIO_MAX7301 |
151 | tristate "Maxim MAX7301 GPIO expander" | |
152 | depends on SPI_MASTER | |
153 | help | |
154 | gpio driver for Maxim MAX7301 SPI GPIO expander. | |
155 | ||
e58b9e27 DB |
156 | config GPIO_MCP23S08 |
157 | tristate "Microchip MCP23S08 I/O expander" | |
158 | depends on SPI_MASTER | |
159 | help | |
160 | SPI driver for Microchip MCP23S08 I/O expander. This provides | |
161 | a GPIO interface supporting inputs and outputs. | |
162 | ||
7444a72e | 163 | endif |