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
i2c_get_adapter(int index)13 struct i2c_adapter *i2c_get_adapter(int index)
14 {
15 struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
16 i2c);
17 int max = ll_entry_count(struct i2c_adapter, i2c);
18 int i;
19
20 if (index >= max) {
21 printf("Error, wrong i2c adapter %d max %d possible\n",
22 index, max);
23 return i2c_adap_p;
24 }
25 if (index == 0)
26 return i2c_adap_p;
27
28 for (i = 0; i < index; i++)
29 i2c_adap_p++;
30
31 return i2c_adap_p;
32 }
33
34 #if !defined(CONFIG_SYS_I2C_DIRECT_BUS)
35 struct i2c_bus_hose i2c_bus[CONFIG_SYS_NUM_I2C_BUSES] =
36 CONFIG_SYS_I2C_BUSES;
37 #endif
38
39 DECLARE_GLOBAL_DATA_PTR;
40
41 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
42 /*
43 * i2c_mux_set()
44 * -------------
45 *
46 * This turns on the given channel on I2C multiplexer chip connected to
47 * a given I2C adapter directly or via other multiplexers. In the latter
48 * case the entire multiplexer chain must be initialized first starting
49 * with the one connected directly to the adapter. When disabling a chain
50 * muxes must be programmed in reverse order, starting with the one
51 * farthest from the adapter.
52 *
53 * mux_id is the multiplexer chip type from defined in i2c.h. So far only
54 * NXP (Philips) PCA954x multiplexers are supported. Switches are NOT
55 * supported (anybody uses them?)
56 */
57
i2c_mux_set(struct i2c_adapter * adap,int mux_id,int chip,int channel)58 static int i2c_mux_set(struct i2c_adapter *adap, int mux_id, int chip,
59 int channel)
60 {
61 uint8_t buf;
62 int ret;
63
64 /* channel < 0 - turn off the mux */
65 if (channel < 0) {
66 buf = 0;
67 ret = adap->write(adap, chip, 0, 0, &buf, 1);
68 if (ret)
69 printf("%s: Could not turn off the mux.\n", __func__);
70 return ret;
71 }
72
73 switch (mux_id) {
74 case I2C_MUX_PCA9540_ID:
75 case I2C_MUX_PCA9542_ID:
76 if (channel > 1)
77 return -1;
78 buf = (uint8_t)((channel & 0x01) | (1 << 2));
79 break;
80 case I2C_MUX_PCA9544_ID:
81 if (channel > 3)
82 return -1;
83 buf = (uint8_t)((channel & 0x03) | (1 << 2));
84 break;
85 case I2C_MUX_PCA9547_ID:
86 if (channel > 7)
87 return -1;
88 buf = (uint8_t)((channel & 0x07) | (1 << 3));
89 break;
90 case I2C_MUX_PCA9548_ID:
91 if (channel > 7)
92 return -1;
93 buf = (uint8_t)(0x01 << channel);
94 break;
95 default:
96 printf("%s: wrong mux id: %d\n", __func__, mux_id);
97 return -1;
98 }
99
100 ret = adap->write(adap, chip, 0, 0, &buf, 1);
101 if (ret)
102 printf("%s: could not set mux: id: %d chip: %x channel: %d\n",
103 __func__, mux_id, chip, channel);
104 return ret;
105 }
106
i2c_mux_set_all(void)107 static int i2c_mux_set_all(void)
108 {
109 struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
110 int i;
111
112 /* Connect requested bus if behind muxes */
113 if (i2c_bus_tmp->next_hop[0].chip != 0) {
114 /* Set all muxes along the path to that bus */
115 for (i = 0; i < CONFIG_SYS_I2C_MAX_HOPS; i++) {
116 int ret;
117
118 if (i2c_bus_tmp->next_hop[i].chip == 0)
119 break;
120
121 ret = i2c_mux_set(I2C_ADAP,
122 i2c_bus_tmp->next_hop[i].mux.id,
123 i2c_bus_tmp->next_hop[i].chip,
124 i2c_bus_tmp->next_hop[i].channel);
125 if (ret != 0)
126 return ret;
127 }
128 }
129 return 0;
130 }
131
i2c_mux_disconnect_all(void)132 static int i2c_mux_disconnect_all(void)
133 {
134 struct i2c_bus_hose *i2c_bus_tmp = &i2c_bus[I2C_BUS];
135 int i;
136 uint8_t buf = 0;
137
138 if (I2C_ADAP->init_done == 0)
139 return 0;
140
141 /* Disconnect current bus (turn off muxes if any) */
142 if ((i2c_bus_tmp->next_hop[0].chip != 0) &&
143 (I2C_ADAP->init_done != 0)) {
144 i = CONFIG_SYS_I2C_MAX_HOPS;
145 do {
146 uint8_t chip;
147 int ret;
148
149 chip = i2c_bus_tmp->next_hop[--i].chip;
150 if (chip == 0)
151 continue;
152
153 ret = I2C_ADAP->write(I2C_ADAP, chip, 0, 0, &buf, 1);
154 if (ret != 0) {
155 printf("i2c: mux disconnect error\n");
156 return ret;
157 }
158 } while (i > 0);
159 }
160
161 return 0;
162 }
163 #endif
164
165 /*
166 * i2c_init_bus():
167 * ---------------
168 *
169 * Initializes one bus. Will initialize the parent adapter. No current bus
170 * changes, no mux (if any) setup.
171 */
i2c_init_bus(unsigned int bus_no,int speed,int slaveaddr)172 static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
173 {
174 if (bus_no >= CONFIG_SYS_NUM_I2C_BUSES)
175 return;
176
177 I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);
178
179 if (gd->flags & GD_FLG_RELOC) {
180 I2C_ADAP->init_done = 1;
181 I2C_ADAP->speed = speed;
182 I2C_ADAP->slaveaddr = slaveaddr;
183 }
184 }
185
186 /* implement possible board specific board init */
i2c_init_board(void)187 __weak void i2c_init_board(void)
188 {
189 }
190
191 /* implement possible for i2c specific early i2c init */
i2c_early_init_f(void)192 __weak void i2c_early_init_f(void)
193 {
194 }
195
196 /*
197 * i2c_init_all():
198 *
199 * not longer needed, will deleted. Actual init the SPD_BUS
200 * for compatibility.
201 * i2c_adap[] must be initialized beforehead with function pointers and
202 * data, including speed and slaveaddr.
203 */
i2c_init_all(void)204 void i2c_init_all(void)
205 {
206 i2c_init_board();
207 i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
208 return;
209 }
210
211 /*
212 * i2c_get_bus_num():
213 * ------------------
214 *
215 * Returns index of currently active I2C bus. Zero-based.
216 */
i2c_get_bus_num(void)217 unsigned int i2c_get_bus_num(void)
218 {
219 return gd->cur_i2c_bus;
220 }
221
222 /*
223 * i2c_set_bus_num():
224 * ------------------
225 *
226 * Change the active I2C bus. Subsequent read/write calls will
227 * go to this one. Sets all of the muxes in a proper condition
228 * if that bus is behind muxes.
229 * If previously selected bus is behind the muxes turns off all the
230 * muxes along the path to that bus.
231 *
232 * bus - bus index, zero based
233 *
234 * Returns: 0 on success, not 0 on failure
235 */
i2c_set_bus_num(unsigned int bus)236 int i2c_set_bus_num(unsigned int bus)
237 {
238 int max;
239
240 if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
241 return 0;
242
243 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
244 if (bus >= CONFIG_SYS_NUM_I2C_BUSES)
245 return -1;
246 #endif
247
248 max = ll_entry_count(struct i2c_adapter, i2c);
249 if (I2C_ADAPTER(bus) >= max) {
250 printf("Error, wrong i2c adapter %d max %d possible\n",
251 I2C_ADAPTER(bus), max);
252 return -2;
253 }
254
255 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
256 i2c_mux_disconnect_all();
257 #endif
258
259 gd->cur_i2c_bus = bus;
260 if (I2C_ADAP->init_done == 0)
261 i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);
262
263 #ifndef CONFIG_SYS_I2C_DIRECT_BUS
264 i2c_mux_set_all();
265 #endif
266 return 0;
267 }
268
269 /*
270 * Probe the given I2C chip address. Returns 0 if a chip responded,
271 * not 0 on failure.
272 */
i2c_probe(uint8_t chip)273 int i2c_probe(uint8_t chip)
274 {
275 return I2C_ADAP->probe(I2C_ADAP, chip);
276 }
277
278 /*
279 * Read/Write interface:
280 * chip: I2C chip address, range 0..127
281 * addr: Memory (register) address within the chip
282 * alen: Number of bytes to use for addr (typically 1, 2 for larger
283 * memories, 0 for register type devices with only one
284 * register)
285 * buffer: Where to read/write the data
286 * len: How many bytes to read/write
287 *
288 * Returns: 0 on success, not 0 on failure
289 */
i2c_read(uint8_t chip,unsigned int addr,int alen,uint8_t * buffer,int len)290 int i2c_read(uint8_t chip, unsigned int addr, int alen,
291 uint8_t *buffer, int len)
292 {
293 return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
294 }
295
i2c_write(uint8_t chip,unsigned int addr,int alen,uint8_t * buffer,int len)296 int i2c_write(uint8_t chip, unsigned int addr, int alen,
297 uint8_t *buffer, int len)
298 {
299 return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
300 }
301
i2c_set_bus_speed(unsigned int speed)302 unsigned int i2c_set_bus_speed(unsigned int speed)
303 {
304 unsigned int ret;
305
306 if (I2C_ADAP->set_bus_speed == NULL)
307 return 0;
308 ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
309 if (gd->flags & GD_FLG_RELOC)
310 I2C_ADAP->speed = (ret == 0) ? speed : 0;
311
312 return ret;
313 }
314
i2c_get_bus_speed(void)315 unsigned int i2c_get_bus_speed(void)
316 {
317 struct i2c_adapter *cur = I2C_ADAP;
318 return cur->speed;
319 }
320
i2c_reg_read(uint8_t addr,uint8_t reg)321 uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
322 {
323 uint8_t buf;
324
325 i2c_read(addr, reg, 1, &buf, 1);
326
327 #ifdef DEBUG
328 printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
329 __func__, i2c_get_bus_num(), addr, reg, buf);
330 #endif
331
332 return buf;
333 }
334
i2c_reg_write(uint8_t addr,uint8_t reg,uint8_t val)335 void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
336 {
337 #ifdef DEBUG
338 printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
339 __func__, i2c_get_bus_num(), addr, reg, val);
340 #endif
341
342 i2c_write(addr, reg, 1, &val, 1);
343 }
344
i2c_init(int speed,int slaveaddr)345 __weak void i2c_init(int speed, int slaveaddr)
346 {
347 i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
348 }
349