summaryrefslogtreecommitdiff
path: root/drivers/gpio/pca953x.c
blob: c8c863765b6db72b86c2e6c468c518c3168b259f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
/*
 * Copyright 2008 Extreme Engineering Solutions, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * Version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * Driver for NXP's 4, 8 and 16 bit I2C gpio expanders (eg pca9537, pca9557,
 * pca9539, etc)
 */

#include <common.h>
#include <i2c.h>
#include <pca953x.h>

/* Default to an address that hopefully won't corrupt other i2c devices */
#ifndef CONFIG_SYS_I2C_PCA953X_ADDR
#define CONFIG_SYS_I2C_PCA953X_ADDR	(~0)
#endif

enum {
	PCA953X_CMD_INFO,
	PCA953X_CMD_DEVICE,
	PCA953X_CMD_OUTPUT,
	PCA953X_CMD_INPUT,
	PCA953X_CMD_INVERT,
};

#ifdef CONFIG_SYS_I2C_PCA953X_WIDTH
struct pca953x_chip_ngpio {
	uint8_t chip;
	uint8_t ngpio;
};

static struct pca953x_chip_ngpio pca953x_chip_ngpios[] =
    CONFIG_SYS_I2C_PCA953X_WIDTH;

/*
 * Determine the number of GPIO pins supported. If we don't know we assume
 * 8 pins.
 */
static int pca953x_ngpio(uint8_t chip)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(pca953x_chip_ngpios); i++)
		if (pca953x_chip_ngpios[i].chip == chip)
			return pca953x_chip_ngpios[i].ngpio;

	return 8;
}
#else
static int pca953x_ngpio(uint8_t chip)
{
	return 8;
}
#endif

/*
 * Modify masked bits in register
 */
static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
{
	uint8_t valb;
	uint16_t valw;

	if (pca953x_ngpio(chip) <= 8) {
		if (i2c_read(chip, addr, 1, &valb, 1))
			return -1;

		valb &= ~mask;
		valb |= data;

		return i2c_write(chip, addr, 1, &valb, 1);
	} else {
		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
			return -1;

		valw = le16_to_cpu(valw);
		valw &= ~mask;
		valw |= data;
		valw = cpu_to_le16(valw);

		return i2c_write(chip, addr << 1, 1, (u8*)&valw, 2);
	}
}

static int pca953x_reg_read(uint8_t chip, uint addr, uint *data)
{
	uint8_t valb;
	uint16_t valw;

	if (pca953x_ngpio(chip) <= 8) {
		if (i2c_read(chip, addr, 1, &valb, 1))
			return -1;
		*data = (int)valb;
	} else {
		if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
			return -1;
		*data = (uint)le16_to_cpu(valw);
	}
	return 0;
}

/*
 * Set output value of IO pins in 'mask' to corresponding value in 'data'
 * 0 = low, 1 = high
 */
int pca953x_set_val(uint8_t chip, uint mask, uint data)
{
	return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
}

/*
 * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
 * 0 = read pin value, 1 = read inverted pin value
 */
int pca953x_set_pol(uint8_t chip, uint mask, uint data)
{
	return pca953x_reg_write(chip, PCA953X_POL, mask, data);
}

/*
 * Set direction of IO pins in 'mask' to corresponding value in 'data'
 * 0 = output, 1 = input
 */
int pca953x_set_dir(uint8_t chip, uint mask, uint data)
{
	return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
}

/*
 * Read current logic level of all IO pins
 */
int pca953x_get_val(uint8_t chip)
{
	uint val;

	if (pca953x_reg_read(chip, PCA953X_IN, &val) < 0)
		return -1;

	return (int)val;
}

#ifdef CONFIG_CMD_PCA953X
#ifdef CONFIG_CMD_PCA953X_INFO
/*
 * Display pca953x information
 */
static int pca953x_info(uint8_t chip)
{
	int i;
	uint data;
	int nr_gpio = pca953x_ngpio(chip);
	int msb = nr_gpio - 1;

	printf("pca953x@ 0x%x (%d pins):\n\n", chip, nr_gpio);
	printf("gpio pins: ");
	for (i = msb; i >= 0; i--)
		printf("%x", i);
	printf("\n");
	for (i = 11 + nr_gpio; i > 0; i--)
		printf("-");
	printf("\n");

	if (pca953x_reg_read(chip, PCA953X_CONF, &data) < 0)
		return -1;
	printf("conf:      ");
	for (i = msb; i >= 0; i--)
		printf("%c", data & (1 << i) ? 'i' : 'o');
	printf("\n");

	if (pca953x_reg_read(chip, PCA953X_POL, &data) < 0)
		return -1;
	printf("invert:    ");
	for (i = msb; i >= 0; i--)
		printf("%c", data & (1 << i) ? '1' : '0');
	printf("\n");

	if (pca953x_reg_read(chip, PCA953X_IN, &data) < 0)
		return -1;
	printf("input:     ");
	for (i = msb; i >= 0; i--)
		printf("%c", data & (1 << i) ? '1' : '0');
	printf("\n");

	if (pca953x_reg_read(chip, PCA953X_OUT, &data) < 0)
		return -1;
	printf("output:    ");
	for (i = msb; i >= 0; i--)
		printf("%c", data & (1 << i) ? '1' : '0');
	printf("\n");

	return 0;
}
#endif /* CONFIG_CMD_PCA953X_INFO */

cmd_tbl_t cmd_pca953x[] = {
	U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
	U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
	U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
#ifdef CONFIG_CMD_PCA953X_INFO
	U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
#endif
};

int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
	int ret = CMD_RET_USAGE, val;
	ulong ul_arg2 = 0;
	ulong ul_arg3 = 0;
	cmd_tbl_t *c;

	c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));

	/* All commands but "device" require 'maxargs' arguments */
	if (!c || !((argc == (c->maxargs)) ||
		(((int)c->cmd == PCA953X_CMD_DEVICE) &&
		 (argc == (c->maxargs - 1))))) {
		return CMD_RET_USAGE;
	}

	/* arg2 used as chip number or pin number */
	if (argc > 2)
		ul_arg2 = simple_strtoul(argv[2], NULL, 16);

	/* arg3 used as pin or invert value */
	if (argc > 3)
		ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;

	switch ((int)c->cmd) {
#ifdef CONFIG_CMD_PCA953X_INFO
	case PCA953X_CMD_INFO:
		ret = pca953x_info(chip);
		if (ret)
			ret = CMD_RET_FAILURE;
		break;
#endif

	case PCA953X_CMD_DEVICE:
		if (argc == 3)
			chip = (uint8_t)ul_arg2;
		printf("Current device address: 0x%x\n", chip);
		ret = CMD_RET_SUCCESS;
		break;

	case PCA953X_CMD_INPUT:
		ret = pca953x_set_dir(chip, (1 << ul_arg2),
				PCA953X_DIR_IN << ul_arg2);
		val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;

		if (ret)
			ret = CMD_RET_FAILURE;
		else
			printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2,
									val);
		break;

	case PCA953X_CMD_OUTPUT:
		ret = pca953x_set_dir(chip, (1 << ul_arg2),
				(PCA953X_DIR_OUT << ul_arg2));
		if (!ret)
			ret = pca953x_set_val(chip, (1 << ul_arg2),
						(ul_arg3 << ul_arg2));
		if (ret)
			ret = CMD_RET_FAILURE;
		break;

	case PCA953X_CMD_INVERT:
		ret = pca953x_set_pol(chip, (1 << ul_arg2),
					(ul_arg3 << ul_arg2));
		if (ret)
			ret = CMD_RET_FAILURE;
		break;
	}

	if (ret == CMD_RET_FAILURE)
		eprintf("Error talking to chip at 0x%x\n", chip);

	return ret;
}

U_BOOT_CMD(
	pca953x,	5,	1,	do_pca953x,
	"pca953x gpio access",
	"device [dev]\n"
	"	- show or set current device address\n"
#ifdef CONFIG_CMD_PCA953X_INFO
	"pca953x info\n"
	"	- display info for current chip\n"
#endif
	"pca953x output pin 0|1\n"
	"	- set pin as output and drive low or high\n"
	"pca953x invert pin 0|1\n"
	"	- disable/enable polarity inversion for reads\n"
	"pca953x input pin\n"
	"	- set pin as input and read value"
);

#endif /* CONFIG_CMD_PCA953X */