1/*
2 * Copyright 2013 Texas Instruments, Inc.
3 * Author: Dan Murphy <dmurphy@ti.com>
4 *
5 * Derived work from the pca953x.c driver
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 */
22
23#include <config.h>
24#include <command.h>
25#include <i2c.h>
26#include <tca642x.h>
27
28/* tca642x register address definitions */
29struct tca642x_bank_info tca642x_regs[] = {
30	{ .input_reg = 0x00,
31	  .output_reg = 0x04,
32	  .polarity_reg = 0x08,
33	  .configuration_reg = 0x0c },
34	{ .input_reg = 0x01,
35	  .output_reg = 0x05,
36	  .polarity_reg = 0x09,
37	  .configuration_reg = 0x0d },
38	{ .input_reg = 0x02,
39	  .output_reg = 0x06,
40	  .polarity_reg = 0x0a,
41	  .configuration_reg = 0x0e },
42};
43
44/*
45 * Modify masked bits in register
46 */
47static int tca642x_reg_write(uchar chip, uint8_t addr,
48		uint8_t reg_bit, uint8_t data)
49{
50	uint8_t valw;
51	int org_bus_num;
52	int ret;
53
54	org_bus_num = i2c_get_bus_num();
55	i2c_set_bus_num(CFG_SYS_I2C_TCA642X_BUS_NUM);
56
57	if (i2c_read(chip, addr, 1, (uint8_t *)&valw, 1)) {
58		printf("Could not read before writing\n");
59		ret = -1;
60		goto error;
61	}
62	valw &= ~reg_bit;
63	valw |= data;
64
65	ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
66
67error:
68	i2c_set_bus_num(org_bus_num);
69	return ret;
70}
71
72static int tca642x_reg_read(uchar chip, uint8_t addr, uint8_t *data)
73{
74	uint8_t valw;
75	int org_bus_num;
76	int ret = 0;
77
78	org_bus_num = i2c_get_bus_num();
79	i2c_set_bus_num(CFG_SYS_I2C_TCA642X_BUS_NUM);
80	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
81		ret = -1;
82		goto error;
83	}
84
85	*data = valw;
86
87error:
88	i2c_set_bus_num(org_bus_num);
89	return ret;
90}
91
92/*
93 * Set output value of IO pins in 'reg_bit' to corresponding value in 'data'
94 * 0 = low, 1 = high
95 */
96int tca642x_set_val(uchar chip, uint8_t gpio_bank,
97					uint8_t reg_bit, uint8_t data)
98{
99	uint8_t out_reg = tca642x_regs[gpio_bank].output_reg;
100
101	return tca642x_reg_write(chip, out_reg, reg_bit, data);
102}
103
104/*
105 * Set read polarity of IO pins in 'reg_bit' to corresponding value in 'data'
106 * 0 = read pin value, 1 = read inverted pin value
107 */
108int tca642x_set_pol(uchar chip, uint8_t gpio_bank,
109					uint8_t reg_bit, uint8_t data)
110{
111	uint8_t pol_reg = tca642x_regs[gpio_bank].polarity_reg;
112
113	return tca642x_reg_write(chip, pol_reg, reg_bit, data);
114}
115
116/*
117 * Set direction of IO pins in 'reg_bit' to corresponding value in 'data'
118 * 0 = output, 1 = input
119 */
120int tca642x_set_dir(uchar chip, uint8_t gpio_bank,
121					uint8_t reg_bit, uint8_t data)
122{
123	uint8_t config_reg = tca642x_regs[gpio_bank].configuration_reg;
124
125	return tca642x_reg_write(chip, config_reg, reg_bit, data);
126}
127
128/*
129 * Read current logic level of all IO pins
130 */
131int tca642x_get_val(uchar chip, uint8_t gpio_bank)
132{
133	uint8_t val;
134	uint8_t in_reg = tca642x_regs[gpio_bank].input_reg;
135
136	if (tca642x_reg_read(chip, in_reg, &val) < 0)
137		return -1;
138
139	return (int)val;
140}
141
142/*
143 * Set the inital register states for the tca642x gpio expander
144 */
145int tca642x_set_inital_state(uchar chip, struct tca642x_bank_info init_data[])
146{
147	int i, ret;
148	uint8_t config_reg;
149	uint8_t polarity_reg;
150	uint8_t output_reg;
151
152	for (i = 0; i < 3; i++) {
153		config_reg = tca642x_regs[i].configuration_reg;
154		ret = tca642x_reg_write(chip, config_reg, 0xff,
155				init_data[i].configuration_reg);
156		polarity_reg = tca642x_regs[i].polarity_reg;
157		ret = tca642x_reg_write(chip, polarity_reg, 0xff,
158				init_data[i].polarity_reg);
159		output_reg = tca642x_regs[i].output_reg;
160		ret = tca642x_reg_write(chip, output_reg, 0xff,
161				init_data[i].output_reg);
162	}
163
164	return ret;
165}
166
167#if defined(CONFIG_CMD_TCA642X) && !defined(CONFIG_SPL_BUILD)
168/*
169 * Display tca642x information
170 */
171static int tca642x_info(uchar chip)
172{
173	int i, j;
174	uint8_t data;
175
176	printf("tca642x@ 0x%x (%d pins):\n", chip, 24);
177	for (i = 0; i < 3; i++) {
178		printf("Bank %i\n", i);
179		if (tca642x_reg_read(chip,
180				     tca642x_regs[i].configuration_reg,
181				     &data) < 0)
182			return -1;
183		printf("\tConfiguration: ");
184		for (j = 7; j >= 0; j--)
185			printf("%c", data & (1 << j) ? 'i' : 'o');
186		printf("\n");
187
188		if (tca642x_reg_read(chip,
189				     tca642x_regs[i].polarity_reg, &data) < 0)
190			return -1;
191		printf("\tPolarity: ");
192		for (j = 7; j >= 0; j--)
193			printf("%c", data & (1 << j) ? '1' : '0');
194		printf("\n");
195
196		if (tca642x_reg_read(chip,
197				     tca642x_regs[i].input_reg, &data) < 0)
198			return -1;
199		printf("\tInput value: ");
200		for (j = 7; j >= 0; j--)
201			printf("%c", data & (1 << j) ? '1' : '0');
202		printf("\n");
203
204		if (tca642x_reg_read(chip,
205				     tca642x_regs[i].output_reg, &data) < 0)
206			return -1;
207		printf("\tOutput value: ");
208		for (j = 7; j >= 0; j--)
209			printf("%c", data & (1 << j) ? '1' : '0');
210		printf("\n");
211	}
212
213	return 0;
214}
215
216static int tca642x_get_bank(int pin)
217{
218	int gpio_bank;
219
220	if (pin <= 7) {
221		gpio_bank = 0;
222	} else if ((pin >= 10) && (pin <= 17)) {
223		gpio_bank = 1;
224	} else if ((pin >= 20) && (pin <= 27)) {
225		gpio_bank = 2;
226	} else {
227		printf("Requested pin is not available\n");
228		gpio_bank = -1;
229	}
230
231	return gpio_bank;
232}
233
234static struct cmd_tbl cmd_tca642x[] = {
235	U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
236	U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
237	U_BOOT_CMD_MKENT(input, 3, 0, (void *)TCA642X_CMD_INPUT, "", ""),
238	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)TCA642X_CMD_INVERT, "", ""),
239	U_BOOT_CMD_MKENT(info, 2, 0, (void *)TCA642X_CMD_INFO, "", ""),
240};
241
242static int do_tca642x(struct cmd_tbl *cmdtp, int flag, int argc,
243		      char *const argv[])
244{
245	static uchar chip = CFG_SYS_I2C_TCA642X_ADDR;
246	int ret = CMD_RET_USAGE, val;
247	int gpio_bank = 0;
248	uint8_t bank_shift;
249	ulong ul_arg2 = 0;
250	ulong ul_arg3 = 0;
251	struct cmd_tbl *c;
252
253	c = find_cmd_tbl(argv[1], cmd_tca642x, ARRAY_SIZE(cmd_tca642x));
254
255	/* All commands but "device" require 'maxargs' arguments */
256	if (!c ||
257	    !((argc == (c->maxargs)) ||
258	    (((int)c->cmd == TCA642X_CMD_DEVICE) &&
259	    (argc == (c->maxargs - 1))))) {
260		return CMD_RET_USAGE;
261	}
262
263	/* arg2 used as chip number or pin number */
264	if (argc > 2)
265		ul_arg2 = dectoul(argv[2], NULL);
266
267	/* arg3 used as pin or invert value */
268	if (argc > 3)
269		ul_arg3 = dectoul(argv[3], NULL) & 0x1;
270
271	switch ((int)c->cmd) {
272	case TCA642X_CMD_INFO:
273		ret = tca642x_info(chip);
274		if (ret)
275			ret = CMD_RET_FAILURE;
276		break;
277
278	case TCA642X_CMD_DEVICE:
279		if (argc == 3)
280			chip = (uint8_t)ul_arg2;
281		printf("Current device address: 0x%x\n", chip);
282		ret = CMD_RET_SUCCESS;
283		break;
284
285	case TCA642X_CMD_INPUT:
286		gpio_bank = tca642x_get_bank(ul_arg2);
287		if (gpio_bank < 0) {
288			ret = CMD_RET_FAILURE;
289			goto error;
290		}
291		bank_shift = ul_arg2 - (gpio_bank * 10);
292		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
293				TCA642X_DIR_IN << bank_shift);
294		val = (tca642x_get_val(chip, gpio_bank) &
295				(1 << bank_shift)) != 0;
296
297		if (ret)
298			ret = CMD_RET_FAILURE;
299		else
300			printf("chip 0x%02x, pin 0x%lx = %d\n", chip,
301			       ul_arg2, val);
302		break;
303
304	case TCA642X_CMD_OUTPUT:
305		gpio_bank = tca642x_get_bank(ul_arg2);
306		if (gpio_bank < 0) {
307			ret = CMD_RET_FAILURE;
308			goto error;
309		}
310		bank_shift = ul_arg2 - (gpio_bank * 10);
311		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
312				(TCA642X_DIR_OUT << bank_shift));
313		if (!ret)
314			ret = tca642x_set_val(chip,
315					      gpio_bank, (1 << bank_shift),
316					      (ul_arg3 << bank_shift));
317		if (ret)
318			ret = CMD_RET_FAILURE;
319		break;
320
321	case TCA642X_CMD_INVERT:
322		gpio_bank = tca642x_get_bank(ul_arg2);
323		if (gpio_bank < 0) {
324			ret = CMD_RET_FAILURE;
325			goto error;
326		}
327		bank_shift = ul_arg2 - (gpio_bank * 10);
328		ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
329					(ul_arg3 << bank_shift));
330		if (ret)
331			ret = CMD_RET_FAILURE;
332		break;
333	}
334error:
335	if (ret == CMD_RET_FAILURE)
336		eprintf("Error talking to chip at 0x%x\n", chip);
337
338	return ret;
339}
340
341U_BOOT_CMD(
342	tca642x,	5,	1,	do_tca642x,
343	"tca642x gpio access",
344	"device [dev]\n"
345	"	- show or set current device address\n"
346	"tca642x info\n"
347	"	- display info for current chip\n"
348	"tca642x output pin 0|1\n"
349	"	- set pin as output and drive low or high\n"
350	"tca642x invert pin 0|1\n"
351	"	- disable/enable polarity inversion for reads\n"
352	"tca642x input pin\n"
353	"	- set pin as input and read value"
354);
355
356#endif /* CONFIG_CMD_TCA642X */
357