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gpio.h
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1 /*
2  * Alchemy GPIO support.
3  *
4  * With CONFIG_GPIOLIB=y different types of on-chip GPIO can be supported within
5  * the same kernel image.
6  * With CONFIG_GPIOLIB=n, your board must select ALCHEMY_GPIOINT_AU1XXX for the
7  * appropriate CPU type (AU1000 currently).
8  */
9 
10 #ifndef _ALCHEMY_GPIO_H_
11 #define _ALCHEMY_GPIO_H_
12 
13 #include <asm/mach-au1x00/au1000.h>
16 
17 /* On Au1000, Au1500 and Au1100 GPIOs won't work as inputs before
18  * SYS_PININPUTEN is written to at least once. On Au1550/Au1200/Au1300 this
19  * register enables use of GPIOs as wake source.
20  */
21 static inline void alchemy_gpio1_input_enable(void)
22 {
24  __raw_writel(0, base + 0x110); /* the write op is key */
25  wmb();
26 }
27 
28 
29 /* Linux gpio framework integration.
30 *
31 * 4 use cases of Alchemy GPIOS:
32 *(1) GPIOLIB=y, ALCHEMY_GPIO_INDIRECT=y:
33 * Board must register gpiochips.
34 *(2) GPIOLIB=y, ALCHEMY_GPIO_INDIRECT=n:
35 * A gpiochip for the 75 GPIOs is registered.
36 *
37 *(3) GPIOLIB=n, ALCHEMY_GPIO_INDIRECT=y:
38 * the boards' gpio.h must provide the linux gpio wrapper functions,
39 *
40 *(4) GPIOLIB=n, ALCHEMY_GPIO_INDIRECT=n:
41 * inlinable gpio functions are provided which enable access to the
42 * Au1300 gpios only by using the numbers straight out of the data-
43 * sheets.
44 
45 * Cases 1 and 3 are intended for boards which want to provide their own
46 * GPIO namespace and -operations (i.e. for example you have 8 GPIOs
47 * which are in part provided by spare Au1300 GPIO pins and in part by
48 * an external FPGA but you still want them to be accssible in linux
49 * as gpio0-7. The board can of course use the alchemy_gpioX_* functions
50 * as required).
51 */
52 
53 #ifdef CONFIG_GPIOLIB
54 
55 /* wraps the cpu-dependent irq_to_gpio functions */
56 /* FIXME: gpiolib needs an irq_to_gpio hook */
57 static inline int __au_irq_to_gpio(unsigned int irq)
58 {
59  switch (alchemy_get_cputype()) {
60  case ALCHEMY_CPU_AU1000...ALCHEMY_CPU_AU1200:
61  return alchemy_irq_to_gpio(irq);
62  case ALCHEMY_CPU_AU1300:
63  return au1300_irq_to_gpio(irq);
64  }
65  return -EINVAL;
66 }
67 
68 
69 /* using gpiolib to provide up to 2 gpio_chips for on-chip gpios */
70 #ifndef CONFIG_ALCHEMY_GPIO_INDIRECT /* case (2) */
71 
72 /* get everything through gpiolib */
73 #define gpio_to_irq __gpio_to_irq
74 #define gpio_get_value __gpio_get_value
75 #define gpio_set_value __gpio_set_value
76 #define gpio_cansleep __gpio_cansleep
77 #define irq_to_gpio __au_irq_to_gpio
78 
79 #include <asm-generic/gpio.h>
80 
81 #endif /* !CONFIG_ALCHEMY_GPIO_INDIRECT */
82 
83 
84 #endif /* CONFIG_GPIOLIB */
85 
86 #endif /* _ALCHEMY_GPIO_H_ */