1 /*
2  * Copyright 2010 eXMeritus, A Boeing Company
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of
7  * the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
17  * MA 02111-1307 USA
18  */
19 
20 #ifndef POWERPC_ASM_MPC85XX_GPIO_H_
21 #define POWERPC_ASM_MPC85XX_GPIO_H_
22 
23 # include <asm/immap_85xx.h>
24 
25 /*
26  * The following internal functions are an MPC85XX-specific GPIO API which
27  * allows setting and querying multiple GPIOs in a single operation.
28  *
29  * All of these look relatively large, but the arguments are almost always
30  * constants, so they compile down to just a few instructions and a
31  * memory-mapped IO operation or two.
32  */
33 static inline void mpc85xx_gpio_set(unsigned int mask,
34 		unsigned int dir, unsigned int val)
35 {
36 	ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
37 
38 	/* First mask off the unwanted parts of "dir" and "val" */
39 	dir &= mask;
40 	val &= mask;
41 
42 	/* Now read in the values we're supposed to preserve */
43 	dir |= (in_be32(&gpio->gpdir) & ~mask);
44 	val |= (in_be32(&gpio->gpdat) & ~mask);
45 
46 	/*
47 	 * Poke the new output values first, then set the direction.  This
48 	 * helps to avoid transient data when switching from input to output
49 	 * and vice versa.
50 	 */
51 	out_be32(&gpio->gpdat, val);
52 	out_be32(&gpio->gpdir, dir);
53 }
54 
55 static inline void mpc85xx_gpio_set_in(unsigned int gpios)
56 {
57 	mpc85xx_gpio_set(gpios, 0x00000000, 0x00000000);
58 }
59 
60 static inline void mpc85xx_gpio_set_low(unsigned int gpios)
61 {
62 	mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0x00000000);
63 }
64 
65 static inline void mpc85xx_gpio_set_high(unsigned int gpios)
66 {
67 	mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0xFFFFFFFF);
68 }
69 
70 static inline unsigned int mpc85xx_gpio_get(unsigned int mask)
71 {
72 	ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
73 
74 	/* Read the requested values */
75 	return in_be32(&gpio->gpdat) & mask;
76 }
77 
78 /*
79  * These implement the generic Linux GPIO API on top of the other functions
80  * in this header.
81  */
82 static inline int gpio_request(unsigned gpio, const char *label)
83 {
84 	/* Compatibility shim */
85 	return 0;
86 }
87 
88 static inline void gpio_free(unsigned gpio)
89 {
90 	/* Compatibility shim */
91 }
92 
93 static inline int gpio_direction_input(unsigned gpio)
94 {
95 	mpc85xx_gpio_set_in(1U << gpio);
96 	return 0;
97 }
98 
99 static inline int gpio_direction_output(unsigned gpio, int value)
100 {
101 	mpc85xx_gpio_set_low(1U << gpio);
102 	return 0;
103 }
104 
105 static inline int gpio_get_value(unsigned gpio)
106 {
107 	return !!mpc85xx_gpio_get(1U << gpio);
108 }
109 
110 static inline void gpio_set_value(unsigned gpio, int value)
111 {
112 	if (value)
113 		mpc85xx_gpio_set_high(1U << gpio);
114 	else
115 		mpc85xx_gpio_set_low(1U << gpio);
116 }
117 
118 static inline int gpio_is_valid(int gpio)
119 {
120 	return (gpio >= 0) && (gpio < 32);
121 }
122 
123 #endif /* not POWERPC_ASM_MPC85XX_GPIO_H_ */
124