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
i2c_get_adapter(int index)15 struct 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(CONFIG_SYS_I2C_DIRECT_BUS)
37 struct i2c_bus_hose i2c_bus[CONFIG_SYS_NUM_I2C_BUSES] =
38 CONFIG_SYS_I2C_BUSES;
39 #endif
40
41 DECLARE_GLOBAL_DATA_PTR;
42
43 #ifndef CONFIG_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
i2c_mux_set(struct i2c_adapter * adap,int mux_id,int chip,int channel)60 static 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
i2c_mux_set_all(void)109 static 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 < CONFIG_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
i2c_mux_disconnect_all(void)134 static 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 = CONFIG_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 */
i2c_init_bus(unsigned int bus_no,int speed,int slaveaddr)174 static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
175 {
176 if (bus_no >= CONFIG_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 */
i2c_init_board(void)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 */
i2c_init_all(void)201 void 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 */
i2c_get_bus_num(void)214 unsigned 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 */
i2c_set_bus_num(unsigned int bus)233 int 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 CONFIG_SYS_I2C_DIRECT_BUS
241 if (bus >= CONFIG_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 CONFIG_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 CONFIG_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 */
i2c_probe(uint8_t chip)270 int 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 */
i2c_read(uint8_t chip,unsigned int addr,int alen,uint8_t * buffer,int len)287 int 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
i2c_write(uint8_t chip,unsigned int addr,int alen,uint8_t * buffer,int len)293 int 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
i2c_set_bus_speed(unsigned int speed)299 unsigned 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
i2c_get_bus_speed(void)312 unsigned int i2c_get_bus_speed(void)
313 {
314 struct i2c_adapter *cur = I2C_ADAP;
315 return cur->speed;
316 }
317
i2c_reg_read(uint8_t addr,uint8_t reg)318 uint8_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
i2c_reg_write(uint8_t addr,uint8_t reg,uint8_t val)332 void 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
i2c_init(int speed,int slaveaddr)342 __weak void i2c_init(int speed, int slaveaddr)
343 {
344 i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
345 }
346