1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
4 *
5 * (C) Copyright 2012
6 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
7 *
8 * Multibus/multiadapter I2C core functions (wrappers)
9 */
10#include <common.h>
11#include <i2c.h>
12#include <linker_lists.h>
13#include <asm/global_data.h>
14
15struct i2c_adapter *i2c_get_adapter(int index)
16{
17	struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
18						i2c);
19	int max = ll_entry_count(struct i2c_adapter, i2c);
20	int i;
21
22	if (index >= max) {
23		printf("Error, wrong i2c adapter %d max %d possible\n",
24		       index, max);
25		return i2c_adap_p;
26	}
27	if (index == 0)
28		return i2c_adap_p;
29
30	for (i = 0; i < index; i++)
31		i2c_adap_p++;
32
33	return i2c_adap_p;
34}
35
36#if !defined(CFG_SYS_I2C_DIRECT_BUS)
37struct i2c_bus_hose i2c_bus[CFG_SYS_NUM_I2C_BUSES] =
38			CFG_SYS_I2C_BUSES;
39#endif
40
41DECLARE_GLOBAL_DATA_PTR;
42
43#ifndef CFG_SYS_I2C_DIRECT_BUS
44/*
45 * i2c_mux_set()
46 * -------------
47 *
48 * This turns on the given channel on I2C multiplexer chip connected to
49 * a given I2C adapter directly or via other multiplexers. In the latter
50 * case the entire multiplexer chain must be initialized first starting
51 * with the one connected directly to the adapter. When disabling a chain
52 * muxes must be programmed in reverse order, starting with the one
53 * farthest from the adapter.
54 *
55 * mux_id is the multiplexer chip type from defined in i2c.h. So far only
56 * NXP (Philips) PCA954x multiplexers are supported. Switches are NOT
57 * supported (anybody uses them?)
58 */
59
60static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
61			int channel)
62{
63	uint8_t	buf;
64	int ret;
65
66	/* channel < 0 - turn off the mux */
67	if (channel < 0) {
68		buf = 0;
69		ret = adap->write(adap, chip, 0, 0, &buf, 1);
70		if (ret)
71			printf("%s: Could not turn off the mux.\n", __func__);
72		return ret;
73	}
74
75	switch (mux_id) {
76	case I2C_MUX_PCA9540_ID:
77	case I2C_MUX_PCA9542_ID:
78		if (channel > 1)
79			return -1;
80		buf = (uint8_t)((channel & 0x01) | (1 << 2));
81		break;
82	case I2C_MUX_PCA9544_ID:
83		if (channel > 3)
84			return -1;
85		buf = (uint8_t)((channel & 0x03) | (1 << 2));
86		break;
87	case I2C_MUX_PCA9547_ID:
88		if (channel > 7)
89			return -1;
90		buf = (uint8_t)((channel & 0x07) | (1 << 3));
91		break;
92	case I2C_MUX_PCA9548_ID:
93		if (channel > 7)
94			return -1;
95		buf = (uint8_t)(0x01 << channel);
96		break;
97	default:
98		printf("%s: wrong mux id: %d\n", __func__, mux_id);
99		return -1;
100	}
101
102	ret = adap->write(adap, chip, 0, 0, &buf, 1);
103	if (ret)
104		printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
105		       __func__, mux_id, chip, channel);
106	return ret;
107}
108
109static int i2c_mux_set_all(void)
110{
111	struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
112	int i;
113
114	/* Connect requested bus if behind muxes */
115	if (i2c_bus_tmp->next_hop[0].chip != 0) {
116		/* Set all muxes along the path to that bus */
117		for (i = 0; i < CFG_SYS_I2C_MAX_HOPS; i++) {
118			int	ret;
119
120			if (i2c_bus_tmp->next_hop[i].chip == 0)
121				break;
122
123			ret = i2c_mux_set(I2C_ADAP,
124					i2c_bus_tmp->next_hop[i].mux.id,
125					i2c_bus_tmp->next_hop[i].chip,
126					i2c_bus_tmp->next_hop[i].channel);
127			if (ret != 0)
128				return ret;
129		}
130	}
131	return 0;
132}
133
134static int i2c_mux_disconnect_all(void)
135{
136	struct	i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
137	int	i;
138	uint8_t	buf = 0;
139
140	if (I2C_ADAP->init_done == 0)
141		return 0;
142
143	/* Disconnect current bus (turn off muxes if any) */
144	if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
145	    (I2C_ADAP->init_done != 0)) {
146		i = CFG_SYS_I2C_MAX_HOPS;
147		do {
148			uint8_t	chip;
149			int ret;
150
151			chip = i2c_bus_tmp->next_hop[--i].chip;
152			if (chip == 0)
153				continue;
154
155			ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
156			if (ret != 0) {
157				printf("i2c: mux disconnect error\n");
158				return ret;
159			}
160		} while (i > 0);
161	}
162
163	return 0;
164}
165#endif
166
167/*
168 * i2c_init_bus():
169 * ---------------
170 *
171 * Initializes one bus. Will initialize the parent adapter. No current bus
172 * changes, no mux (if any) setup.
173 */
174static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
175{
176	if (bus_no >= CFG_SYS_NUM_I2C_BUSES)
177		return;
178
179	I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
180
181	if (gd->flags & GD_FLG_RELOC) {
182		I2C_ADAP->init_done = 1;
183		I2C_ADAP->speed = speed;
184		I2C_ADAP->slaveaddr = slaveaddr;
185	}
186}
187
188/* implement possible board specific board init */
189__weak void i2c_init_board(void)
190{
191}
192
193/*
194 * i2c_init_all():
195 *
196 * not longer needed, will deleted. Actual init the SPD_BUS
197 * for compatibility.
198 * i2c_adap[] must be initialized beforehead with function pointers and
199 * data, including speed and slaveaddr.
200 */
201void i2c_init_all(void)
202{
203	i2c_init_board();
204	i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
205	return;
206}
207
208/*
209 * i2c_get_bus_num():
210 * ------------------
211 *
212 *  Returns index of currently active I2C bus.  Zero-based.
213 */
214unsigned int i2c_get_bus_num(void)
215{
216	return gd->cur_i2c_bus;
217}
218
219/*
220 * i2c_set_bus_num():
221 * ------------------
222 *
223 *  Change the active I2C bus. Subsequent read/write calls will
224 *  go to this one. Sets all of the muxes in a proper condition
225 *  if that bus is behind muxes.
226 *  If previously selected bus is behind the muxes turns off all the
227 *  muxes along the path to that bus.
228 *
229 *	bus - bus index, zero based
230 *
231 *	Returns: 0 on success, not 0 on failure
232 */
233int i2c_set_bus_num(unsigned int bus)
234{
235	int max;
236
237	if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
238		return 0;
239
240#ifndef CFG_SYS_I2C_DIRECT_BUS
241	if (bus >= CFG_SYS_NUM_I2C_BUSES)
242		return -1;
243#endif
244
245	max = ll_entry_count(struct i2c_adapter, i2c);
246	if (I2C_ADAPTER(bus) >= max) {
247		printf("Error, wrong i2c adapter %d max %d possible\n",
248		       I2C_ADAPTER(bus), max);
249		return -2;
250	}
251
252#ifndef CFG_SYS_I2C_DIRECT_BUS
253	i2c_mux_disconnect_all();
254#endif
255
256	gd->cur_i2c_bus = bus;
257	if (I2C_ADAP->init_done == 0)
258		i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
259
260#ifndef CFG_SYS_I2C_DIRECT_BUS
261	i2c_mux_set_all();
262#endif
263	return 0;
264}
265
266/*
267 * Probe the given I2C chip address.  Returns 0 if a chip responded,
268 * not 0 on failure.
269 */
270int i2c_probe(uint8_t chip)
271{
272	return I2C_ADAP->probe(I2C_ADAP, chip);
273}
274
275/*
276 * Read/Write interface:
277 *   chip:    I2C chip address, range 0..127
278 *   addr:    Memory (register) address within the chip
279 *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
280 *              memories, 0 for register type devices with only one
281 *              register)
282 *   buffer:  Where to read/write the data
283 *   len:     How many bytes to read/write
284 *
285 *   Returns: 0 on success, not 0 on failure
286 */
287int i2c_read(uint8_t chip, unsigned int addr, int alen,
288				uint8_t *buffer, int len)
289{
290	return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
291}
292
293int i2c_write(uint8_t chip, unsigned int addr, int alen,
294				uint8_t *buffer, int len)
295{
296	return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
297}
298
299unsigned int i2c_set_bus_speed(unsigned int speed)
300{
301	unsigned int ret;
302
303	if (I2C_ADAP->set_bus_speed == NULL)
304		return 0;
305	ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
306	if (gd->flags & GD_FLG_RELOC)
307		I2C_ADAP->speed = (ret == 0) ? speed : 0;
308
309	return ret;
310}
311
312unsigned int i2c_get_bus_speed(void)
313{
314	struct i2c_adapter *cur = I2C_ADAP;
315	return cur->speed;
316}
317
318uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
319{
320	uint8_t buf;
321
322	i2c_read(addr, reg, 1, &buf, 1);
323
324#ifdef DEBUG
325	printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
326	       __func__, i2c_get_bus_num(), addr, reg, buf);
327#endif
328
329	return buf;
330}
331
332void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
333{
334#ifdef DEBUG
335	printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
336	       __func__, i2c_get_bus_num(), addr, reg, val);
337#endif
338
339	i2c_write(addr, reg, 1, &val, 1);
340}
341
342__weak void i2c_init(int speed, int slaveaddr)
343{
344	i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
345}
346