xref: /openbmc/u-boot/drivers/gpio/pca953x.c (revision a3b36c84)
1 /*
2  * Copyright 2008 Extreme Engineering Solutions, Inc.
3  *
4  * SPDX-License-Identifier:	GPL-2.0
5  */
6 
7 /*
8  * Driver for NXP's 4, 8 and 16 bit I2C gpio expanders (eg pca9537, pca9557,
9  * pca9539, etc)
10  */
11 
12 #include <common.h>
13 #include <i2c.h>
14 #include <pca953x.h>
15 
16 /* Default to an address that hopefully won't corrupt other i2c devices */
17 #ifndef CONFIG_SYS_I2C_PCA953X_ADDR
18 #define CONFIG_SYS_I2C_PCA953X_ADDR	(~0)
19 #endif
20 
21 enum {
22 	PCA953X_CMD_INFO,
23 	PCA953X_CMD_DEVICE,
24 	PCA953X_CMD_OUTPUT,
25 	PCA953X_CMD_INPUT,
26 	PCA953X_CMD_INVERT,
27 };
28 
29 #ifdef CONFIG_SYS_I2C_PCA953X_WIDTH
30 struct pca953x_chip_ngpio {
31 	uint8_t chip;
32 	uint8_t ngpio;
33 };
34 
35 static struct pca953x_chip_ngpio pca953x_chip_ngpios[] =
36     CONFIG_SYS_I2C_PCA953X_WIDTH;
37 
38 /*
39  * Determine the number of GPIO pins supported. If we don't know we assume
40  * 8 pins.
41  */
42 static int pca953x_ngpio(uint8_t chip)
43 {
44 	int i;
45 
46 	for (i = 0; i < ARRAY_SIZE(pca953x_chip_ngpios); i++)
47 		if (pca953x_chip_ngpios[i].chip == chip)
48 			return pca953x_chip_ngpios[i].ngpio;
49 
50 	return 8;
51 }
52 #else
53 static int pca953x_ngpio(uint8_t chip)
54 {
55 	return 8;
56 }
57 #endif
58 
59 /*
60  * Modify masked bits in register
61  */
62 static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
63 {
64 	uint8_t valb;
65 	uint16_t valw;
66 
67 	if (pca953x_ngpio(chip) <= 8) {
68 		if (i2c_read(chip, addr, 1, &valb, 1))
69 			return -1;
70 
71 		valb &= ~mask;
72 		valb |= data;
73 
74 		return i2c_write(chip, addr, 1, &valb, 1);
75 	} else {
76 		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
77 			return -1;
78 
79 		valw = le16_to_cpu(valw);
80 		valw &= ~mask;
81 		valw |= data;
82 		valw = cpu_to_le16(valw);
83 
84 		return i2c_write(chip, addr << 1, 1, (u8*)&valw, 2);
85 	}
86 }
87 
88 static int pca953x_reg_read(uint8_t chip, uint addr, uint *data)
89 {
90 	uint8_t valb;
91 	uint16_t valw;
92 
93 	if (pca953x_ngpio(chip) <= 8) {
94 		if (i2c_read(chip, addr, 1, &valb, 1))
95 			return -1;
96 		*data = (int)valb;
97 	} else {
98 		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
99 			return -1;
100 		*data = (uint)le16_to_cpu(valw);
101 	}
102 	return 0;
103 }
104 
105 /*
106  * Set output value of IO pins in 'mask' to corresponding value in 'data'
107  * 0 = low, 1 = high
108  */
109 int pca953x_set_val(uint8_t chip, uint mask, uint data)
110 {
111 	return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
112 }
113 
114 /*
115  * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
116  * 0 = read pin value, 1 = read inverted pin value
117  */
118 int pca953x_set_pol(uint8_t chip, uint mask, uint data)
119 {
120 	return pca953x_reg_write(chip, PCA953X_POL, mask, data);
121 }
122 
123 /*
124  * Set direction of IO pins in 'mask' to corresponding value in 'data'
125  * 0 = output, 1 = input
126  */
127 int pca953x_set_dir(uint8_t chip, uint mask, uint data)
128 {
129 	return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
130 }
131 
132 /*
133  * Read current logic level of all IO pins
134  */
135 int pca953x_get_val(uint8_t chip)
136 {
137 	uint val;
138 
139 	if (pca953x_reg_read(chip, PCA953X_IN, &val) < 0)
140 		return -1;
141 
142 	return (int)val;
143 }
144 
145 #ifdef CONFIG_CMD_PCA953X
146 /*
147  * Display pca953x information
148  */
149 static int pca953x_info(uint8_t chip)
150 {
151 	int i;
152 	uint data;
153 	int nr_gpio = pca953x_ngpio(chip);
154 	int msb = nr_gpio - 1;
155 
156 	printf("pca953x@ 0x%x (%d pins):\n\n", chip, nr_gpio);
157 	printf("gpio pins: ");
158 	for (i = msb; i >= 0; i--)
159 		printf("%x", i);
160 	printf("\n");
161 	for (i = 11 + nr_gpio; i > 0; i--)
162 		printf("-");
163 	printf("\n");
164 
165 	if (pca953x_reg_read(chip, PCA953X_CONF, &data) < 0)
166 		return -1;
167 	printf("conf:      ");
168 	for (i = msb; i >= 0; i--)
169 		printf("%c", data & (1 << i) ? 'i' : 'o');
170 	printf("\n");
171 
172 	if (pca953x_reg_read(chip, PCA953X_POL, &data) < 0)
173 		return -1;
174 	printf("invert:    ");
175 	for (i = msb; i >= 0; i--)
176 		printf("%c", data & (1 << i) ? '1' : '0');
177 	printf("\n");
178 
179 	if (pca953x_reg_read(chip, PCA953X_IN, &data) < 0)
180 		return -1;
181 	printf("input:     ");
182 	for (i = msb; i >= 0; i--)
183 		printf("%c", data & (1 << i) ? '1' : '0');
184 	printf("\n");
185 
186 	if (pca953x_reg_read(chip, PCA953X_OUT, &data) < 0)
187 		return -1;
188 	printf("output:    ");
189 	for (i = msb; i >= 0; i--)
190 		printf("%c", data & (1 << i) ? '1' : '0');
191 	printf("\n");
192 
193 	return 0;
194 }
195 
196 cmd_tbl_t cmd_pca953x[] = {
197 	U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
198 	U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
199 	U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
200 	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
201 	U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
202 };
203 
204 int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
205 {
206 	static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
207 	int ret = CMD_RET_USAGE, val;
208 	ulong ul_arg2 = 0;
209 	ulong ul_arg3 = 0;
210 	cmd_tbl_t *c;
211 
212 	c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
213 
214 	/* All commands but "device" require 'maxargs' arguments */
215 	if (!c || !((argc == (c->maxargs)) ||
216 		(((long)c->cmd == PCA953X_CMD_DEVICE) &&
217 		 (argc == (c->maxargs - 1))))) {
218 		return CMD_RET_USAGE;
219 	}
220 
221 	/* arg2 used as chip number or pin number */
222 	if (argc > 2)
223 		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
224 
225 	/* arg3 used as pin or invert value */
226 	if (argc > 3)
227 		ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
228 
229 	switch ((long)c->cmd) {
230 	case PCA953X_CMD_INFO:
231 		ret = pca953x_info(chip);
232 		if (ret)
233 			ret = CMD_RET_FAILURE;
234 		break;
235 
236 	case PCA953X_CMD_DEVICE:
237 		if (argc == 3)
238 			chip = (uint8_t)ul_arg2;
239 		printf("Current device address: 0x%x\n", chip);
240 		ret = CMD_RET_SUCCESS;
241 		break;
242 
243 	case PCA953X_CMD_INPUT:
244 		ret = pca953x_set_dir(chip, (1 << ul_arg2),
245 				PCA953X_DIR_IN << ul_arg2);
246 		val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
247 
248 		if (ret)
249 			ret = CMD_RET_FAILURE;
250 		else
251 			printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2,
252 									val);
253 		break;
254 
255 	case PCA953X_CMD_OUTPUT:
256 		ret = pca953x_set_dir(chip, (1 << ul_arg2),
257 				(PCA953X_DIR_OUT << ul_arg2));
258 		if (!ret)
259 			ret = pca953x_set_val(chip, (1 << ul_arg2),
260 						(ul_arg3 << ul_arg2));
261 		if (ret)
262 			ret = CMD_RET_FAILURE;
263 		break;
264 
265 	case PCA953X_CMD_INVERT:
266 		ret = pca953x_set_pol(chip, (1 << ul_arg2),
267 					(ul_arg3 << ul_arg2));
268 		if (ret)
269 			ret = CMD_RET_FAILURE;
270 		break;
271 	}
272 
273 	if (ret == CMD_RET_FAILURE)
274 		eprintf("Error talking to chip at 0x%x\n", chip);
275 
276 	return ret;
277 }
278 
279 U_BOOT_CMD(
280 	pca953x,	5,	1,	do_pca953x,
281 	"pca953x gpio access",
282 	"device [dev]\n"
283 	"	- show or set current device address\n"
284 	"pca953x info\n"
285 	"	- display info for current chip\n"
286 	"pca953x output pin 0|1\n"
287 	"	- set pin as output and drive low or high\n"
288 	"pca953x invert pin 0|1\n"
289 	"	- disable/enable polarity inversion for reads\n"
290 	"pca953x input pin\n"
291 	"	- set pin as input and read value"
292 );
293 
294 #endif /* CONFIG_CMD_PCA953X */
295