xref: /openbmc/u-boot/drivers/gpio/pca953x.c (revision 6b7c0f5e)
1 /*
2  * Copyright 2008 Extreme Engineering Solutions, Inc.
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
6  * Version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
16  * MA 02111-1307 USA
17  */
18 
19 /*
20  * Driver for NXP's 4 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
21  * TODO: support additional devices with more than 8-bits GPIO
22  */
23 
24 #include <common.h>
25 #include <i2c.h>
26 #include <pca953x.h>
27 
28 /* Default to an address that hopefully won't corrupt other i2c devices */
29 #ifndef CONFIG_SYS_I2C_PCA953X_ADDR
30 #define CONFIG_SYS_I2C_PCA953X_ADDR	(~0)
31 #endif
32 
33 enum {
34 	PCA953X_CMD_INFO,
35 	PCA953X_CMD_DEVICE,
36 	PCA953X_CMD_OUTPUT,
37 	PCA953X_CMD_INPUT,
38 	PCA953X_CMD_INVERT,
39 };
40 
41 /*
42  * Modify masked bits in register
43  */
44 static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
45 {
46 	uint8_t val;
47 
48 	if (i2c_read(chip, addr, 1, &val, 1))
49 		return -1;
50 
51 	val &= ~mask;
52 	val |= data;
53 
54 	return i2c_write(chip, addr, 1, &val, 1);
55 }
56 
57 /*
58  * Set output value of IO pins in 'mask' to corresponding value in 'data'
59  * 0 = low, 1 = high
60  */
61 int pca953x_set_val(uint8_t chip, uint mask, uint data)
62 {
63 	return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
64 }
65 
66 /*
67  * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
68  * 0 = read pin value, 1 = read inverted pin value
69  */
70 int pca953x_set_pol(uint8_t chip, uint mask, uint data)
71 {
72 	return pca953x_reg_write(chip, PCA953X_POL, mask, data);
73 }
74 
75 /*
76  * Set direction of IO pins in 'mask' to corresponding value in 'data'
77  * 0 = output, 1 = input
78  */
79 int pca953x_set_dir(uint8_t chip, uint mask, uint data)
80 {
81 	return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
82 }
83 
84 /*
85  * Read current logic level of all IO pins
86  */
87 int pca953x_get_val(uint8_t chip)
88 {
89 	uint8_t val;
90 
91 	if (i2c_read(chip, 0, 1, &val, 1))
92 		return -1;
93 
94 	return (int)val;
95 }
96 
97 #ifdef CONFIG_CMD_PCA953X
98 #ifdef CONFIG_CMD_PCA953X_INFO
99 /*
100  * Display pca953x information
101  */
102 static int pca953x_info(uint8_t chip)
103 {
104 	int i;
105 	uint8_t data;
106 
107 	printf("pca953x@ 0x%x:\n\n", chip);
108 	printf("gpio pins: 76543210\n");
109 	printf("-------------------\n");
110 
111 	if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
112 		return -1;
113 	printf("conf:      ");
114 	for (i = 7; i >= 0; i--)
115 		printf("%c", data & (1 << i) ? 'i' : 'o');
116 	printf("\n");
117 
118 	if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
119 		return -1;
120 	printf("invert:    ");
121 	for (i = 7; i >= 0; i--)
122 		printf("%c", data & (1 << i) ? '1' : '0');
123 	printf("\n");
124 
125 	if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
126 		return -1;
127 	printf("input:     ");
128 	for (i = 7; i >= 0; i--)
129 		printf("%c", data & (1 << i) ? '1' : '0');
130 	printf("\n");
131 
132 	if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
133 		return -1;
134 	printf("output:    ");
135 	for (i = 7; i >= 0; i--)
136 		printf("%c", data & (1 << i) ? '1' : '0');
137 	printf("\n");
138 
139 	return 0;
140 }
141 #endif /* CONFIG_CMD_PCA953X_INFO */
142 
143 cmd_tbl_t cmd_pca953x[] = {
144 	U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
145 	U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
146 	U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
147 	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
148 #ifdef CONFIG_CMD_PCA953X_INFO
149 	U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
150 #endif
151 };
152 
153 int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
154 {
155 	static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
156 	int val;
157 	ulong ul_arg2 = 0;
158 	ulong ul_arg3 = 0;
159 	cmd_tbl_t *c;
160 
161 	c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
162 
163 	/* All commands but "device" require 'maxargs' arguments */
164 	if (!c || !((argc == (c->maxargs)) ||
165 		(((int)c->cmd == PCA953X_CMD_DEVICE) &&
166 		 (argc == (c->maxargs - 1))))) {
167 		return cmd_usage(cmdtp);
168 	}
169 
170 	/* arg2 used as chip number or pin number */
171 	if (argc > 2)
172 		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
173 
174 	/* arg3 used as pin or invert value */
175 	if (argc > 3)
176 		ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
177 
178 	switch ((int)c->cmd) {
179 #ifdef CONFIG_CMD_PCA953X_INFO
180 	case PCA953X_CMD_INFO:
181 		return pca953x_info(chip);
182 #endif
183 	case PCA953X_CMD_DEVICE:
184 		if (argc == 3)
185 			chip = (uint8_t)ul_arg2;
186 		printf("Current device address: 0x%x\n", chip);
187 		return 0;
188 	case PCA953X_CMD_INPUT:
189 		pca953x_set_dir(chip, (1 << ul_arg2),
190 				PCA953X_DIR_IN << ul_arg2);
191 		val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
192 
193 		printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2, val);
194 		return val;
195 	case PCA953X_CMD_OUTPUT:
196 		pca953x_set_dir(chip, (1 << ul_arg2),
197 				(PCA953X_DIR_OUT << ul_arg2));
198 		return pca953x_set_val(chip, (1 << ul_arg2),
199 					(ul_arg3 << ul_arg2));
200 	case PCA953X_CMD_INVERT:
201 		return pca953x_set_pol(chip, (1 << ul_arg2),
202 					(ul_arg3 << ul_arg2));
203 	default:
204 		/* We should never get here */
205 		return 1;
206 	}
207 }
208 
209 U_BOOT_CMD(
210 	pca953x,	5,	1,	do_pca953x,
211 	"pca953x gpio access",
212 	"device [dev]\n"
213 	"	- show or set current device address\n"
214 #ifdef CONFIG_CMD_PCA953X_INFO
215 	"pca953x info\n"
216 	"	- display info for current chip\n"
217 #endif
218 	"pca953x output pin 0|1\n"
219 	"	- set pin as output and drive low or high\n"
220 	"pca953x invert pin 0|1\n"
221 	"	- disable/enable polarity inversion for reads\n"
222 	"pca953x intput pin\n"
223 	"	- set pin as input and read value"
224 );
225 
226 #endif /* CONFIG_CMD_PCA953X */
227