summaryrefslogtreecommitdiff
path: root/drivers/i2c/i2c_core.c
blob: cccd45027db3411e71bd46fad61e622a478f7dde (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2009 Sergey Kubushyn <ksi@koi8.net>
 *
 * (C) Copyright 2012
 * Heiko Schocher, DENX Software Engineering, hs@denx.de.
 *
 * Multibus/multiadapter I2C core functions (wrappers)
 */
#include <config.h>
#include <i2c.h>
#include <linker_lists.h>
#include <asm/global_data.h>

struct i2c_adapter *i2c_get_adapter(int index)
{
	struct i2c_adapter *i2c_adap_p = ll_entry_start(struct i2c_adapter,
						i2c);
	int max = ll_entry_count(struct i2c_adapter, i2c);
	int i;

	if (index >= max) {
		printf("Error, wrong i2c adapter %d max %d possible\n",
		       index, max);
		return i2c_adap_p;
	}
	if (index == 0)
		return i2c_adap_p;

	for (i = 0; i < index; i++)
		i2c_adap_p++;

	return i2c_adap_p;
}

DECLARE_GLOBAL_DATA_PTR;

/*
 * i2c_init_bus():
 * ---------------
 *
 * Initializes one bus. Will initialize the parent adapter. No current bus
 * changes, no mux (if any) setup.
 */
static void i2c_init_bus(unsigned int bus_no, int speed, int slaveaddr)
{
	if (bus_no >= CFG_SYS_NUM_I2C_BUSES)
		return;

	I2C_ADAP->init(I2C_ADAP, speed, slaveaddr);

	if (gd->flags & GD_FLG_RELOC) {
		I2C_ADAP->init_done = 1;
		I2C_ADAP->speed = speed;
		I2C_ADAP->slaveaddr = slaveaddr;
	}
}

/* implement possible board specific board init */
__weak void i2c_init_board(void)
{
}

/*
 * i2c_init_all():
 *
 * not longer needed, will deleted. Actual init the SPD_BUS
 * for compatibility.
 * i2c_adap[] must be initialized beforehead with function pointers and
 * data, including speed and slaveaddr.
 */
void i2c_init_all(void)
{
	i2c_init_board();
	i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
	return;
}

/*
 * i2c_get_bus_num():
 * ------------------
 *
 *  Returns index of currently active I2C bus.  Zero-based.
 */
unsigned int i2c_get_bus_num(void)
{
	return gd->cur_i2c_bus;
}

/*
 * i2c_set_bus_num():
 * ------------------
 *
 *  Change the active I2C bus. Subsequent read/write calls will
 *  go to this one. Sets all of the muxes in a proper condition
 *  if that bus is behind muxes.
 *  If previously selected bus is behind the muxes turns off all the
 *  muxes along the path to that bus.
 *
 *	bus - bus index, zero based
 *
 *	Returns: 0 on success, not 0 on failure
 */
int i2c_set_bus_num(unsigned int bus)
{
	int max;

	if ((bus == I2C_BUS) && (I2C_ADAP->init_done > 0))
		return 0;

	max = ll_entry_count(struct i2c_adapter, i2c);
	if (I2C_ADAPTER(bus) >= max) {
		printf("Error, wrong i2c adapter %d max %d possible\n",
		       I2C_ADAPTER(bus), max);
		return -2;
	}

	gd->cur_i2c_bus = bus;
	if (I2C_ADAP->init_done == 0)
		i2c_init_bus(bus, I2C_ADAP->speed, I2C_ADAP->slaveaddr);

	return 0;
}

/*
 * Probe the given I2C chip address.  Returns 0 if a chip responded,
 * not 0 on failure.
 */
int i2c_probe(uint8_t chip)
{
	return I2C_ADAP->probe(I2C_ADAP, chip);
}

/*
 * Read/Write interface:
 *   chip:    I2C chip address, range 0..127
 *   addr:    Memory (register) address within the chip
 *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 *              memories, 0 for register type devices with only one
 *              register)
 *   buffer:  Where to read/write the data
 *   len:     How many bytes to read/write
 *
 *   Returns: 0 on success, not 0 on failure
 */
int i2c_read(uint8_t chip, unsigned int addr, int alen,
				uint8_t *buffer, int len)
{
	return I2C_ADAP->read(I2C_ADAP, chip, addr, alen, buffer, len);
}

int i2c_write(uint8_t chip, unsigned int addr, int alen,
				uint8_t *buffer, int len)
{
	return I2C_ADAP->write(I2C_ADAP, chip, addr, alen, buffer, len);
}

unsigned int i2c_set_bus_speed(unsigned int speed)
{
	unsigned int ret;

	if (I2C_ADAP->set_bus_speed == NULL)
		return 0;
	ret = I2C_ADAP->set_bus_speed(I2C_ADAP, speed);
	if (gd->flags & GD_FLG_RELOC)
		I2C_ADAP->speed = (ret == 0) ? speed : 0;

	return ret;
}

unsigned int i2c_get_bus_speed(void)
{
	struct i2c_adapter *cur = I2C_ADAP;
	return cur->speed;
}

uint8_t i2c_reg_read(uint8_t addr, uint8_t reg)
{
	uint8_t buf;

	i2c_read(addr, reg, 1, &buf, 1);

#ifdef DEBUG
	printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
	       __func__, i2c_get_bus_num(), addr, reg, buf);
#endif

	return buf;
}

void i2c_reg_write(uint8_t addr, uint8_t reg, uint8_t val)
{
#ifdef DEBUG
	printf("%s: bus=%d addr=0x%02x, reg=0x%02x, val=0x%02x\n",
	       __func__, i2c_get_bus_num(), addr, reg, val);
#endif

	i2c_write(addr, reg, 1, &val, 1);
}

__weak void i2c_init(int speed, int slaveaddr)
{
	i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
}