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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
/*
* LPC32xx I2C interface driver
*
* (C) Copyright 2014-2015 DENX Software Engineering GmbH
* Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud@3adev.fr>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <i2c.h>
#include <linux/errno.h>
#include <asm/arch/clk.h>
/*
* Provide default speed and slave if target did not
*/
#if !defined(CONFIG_SYS_I2C_LPC32XX_SPEED)
#define CONFIG_SYS_I2C_LPC32XX_SPEED 350000
#endif
#if !defined(CONFIG_SYS_I2C_LPC32XX_SLAVE)
#define CONFIG_SYS_I2C_LPC32XX_SLAVE 0
#endif
/* i2c register set */
struct lpc32xx_i2c_registers {
union {
u32 rx;
u32 tx;
};
u32 stat;
u32 ctrl;
u32 clk_hi;
u32 clk_lo;
u32 adr;
u32 rxfl;
u32 txfl;
u32 rxb;
u32 txb;
u32 stx;
u32 stxfl;
};
/* TX register fields */
#define LPC32XX_I2C_TX_START 0x00000100
#define LPC32XX_I2C_TX_STOP 0x00000200
/* Control register values */
#define LPC32XX_I2C_SOFT_RESET 0x00000100
/* Status register values */
#define LPC32XX_I2C_STAT_TFF 0x00000400
#define LPC32XX_I2C_STAT_RFE 0x00000200
#define LPC32XX_I2C_STAT_DRMI 0x00000008
#define LPC32XX_I2C_STAT_NAI 0x00000004
#define LPC32XX_I2C_STAT_TDI 0x00000001
static struct lpc32xx_i2c_registers *lpc32xx_i2c[] = {
(struct lpc32xx_i2c_registers *)I2C1_BASE,
(struct lpc32xx_i2c_registers *)I2C2_BASE,
(struct lpc32xx_i2c_registers *)(USB_BASE + 0x300)
};
/* Set I2C bus speed */
static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
int half_period;
if (speed == 0)
return -EINVAL;
/* OTG I2C clock source and CLK registers are different */
if (adap->hwadapnr == 2) {
half_period = (get_periph_clk_rate() / speed) / 2;
if (half_period > 0xFF)
return -EINVAL;
} else {
half_period = (get_hclk_clk_rate() / speed) / 2;
if (half_period > 0x3FF)
return -EINVAL;
}
writel(half_period, &lpc32xx_i2c[adap->hwadapnr]->clk_hi);
writel(half_period, &lpc32xx_i2c[adap->hwadapnr]->clk_lo);
return 0;
}
/* I2C init called by cmd_i2c when doing 'i2c reset'. */
static void _i2c_init(struct i2c_adapter *adap,
int requested_speed, int slaveadd)
{
struct lpc32xx_i2c_registers *i2c = lpc32xx_i2c[adap->hwadapnr];
/* soft reset (auto-clears) */
writel(LPC32XX_I2C_SOFT_RESET, &i2c->ctrl);
/* set HI and LO periods for half of the default speed */
lpc32xx_i2c_set_bus_speed(adap, requested_speed);
}
/* I2C probe called by cmd_i2c when doing 'i2c probe'. */
static int lpc32xx_i2c_probe(struct i2c_adapter *adap, u8 dev)
{
struct lpc32xx_i2c_registers *i2c = lpc32xx_i2c[adap->hwadapnr];
int stat;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &i2c->ctrl);
while (readl(&i2c->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* Addre slave for write with start before and stop after */
writel((dev<<1) | LPC32XX_I2C_TX_START | LPC32XX_I2C_TX_STOP,
&i2c->tx);
/* wait for end of transation */
while (!((stat = readl(&i2c->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* was there no acknowledge? */
return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0;
}
/*
* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
* Begin write, send address byte(s), begin read, receive data bytes, end.
*/
static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
struct lpc32xx_i2c_registers *i2c = lpc32xx_i2c[adap->hwadapnr];
int stat, wlen;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &i2c->ctrl);
while (readl(&i2c->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* do we need to write an address at all? */
if (alen) {
/* Address slave in write mode */
writel((dev<<1) | LPC32XX_I2C_TX_START, &i2c->tx);
/* write address bytes */
while (alen--) {
/* compute address byte + stop for the last one */
int a = (addr >> (8 * alen)) & 0xff;
if (!alen)
a |= LPC32XX_I2C_TX_STOP;
/* Send address byte */
writel(a, &i2c->tx);
}
/* wait for end of transation */
while (!((stat = readl(&i2c->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &i2c->stat);
}
/* do we have to read data at all? */
if (length) {
/* Address slave in read mode */
writel(1 | (dev<<1) | LPC32XX_I2C_TX_START, &i2c->tx);
wlen = length;
/* get data */
while (length | wlen) {
/* read status for TFF and RFE */
stat = readl(&i2c->stat);
/* must we, can we write a trigger byte? */
if ((wlen > 0)
& (!(stat & LPC32XX_I2C_STAT_TFF))) {
wlen--;
/* write trigger byte + stop if last */
writel(wlen ? 0 :
LPC32XX_I2C_TX_STOP, &i2c->tx);
}
/* must we, can we read a data byte? */
if ((length > 0)
& (!(stat & LPC32XX_I2C_STAT_RFE))) {
length--;
/* read byte */
*(data++) = readl(&i2c->rx);
}
}
/* wait for end of transation */
while (!((stat = readl(&i2c->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &i2c->stat);
}
/* success */
return 0;
}
/*
* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
* Begin write, send address byte(s), send data bytes, end.
*/
static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
int alen, u8 *data, int length)
{
struct lpc32xx_i2c_registers *i2c = lpc32xx_i2c[adap->hwadapnr];
int stat;
/* Soft-reset the controller */
writel(LPC32XX_I2C_SOFT_RESET, &i2c->ctrl);
while (readl(&i2c->ctrl) & LPC32XX_I2C_SOFT_RESET)
;
/* do we need to write anything at all? */
if (alen | length)
/* Address slave in write mode */
writel((dev<<1) | LPC32XX_I2C_TX_START, &i2c->tx);
else
return 0;
/* write address bytes */
while (alen) {
/* wait for transmit fifo not full */
stat = readl(&i2c->stat);
if (!(stat & LPC32XX_I2C_STAT_TFF)) {
alen--;
int a = (addr >> (8 * alen)) & 0xff;
if (!(alen | length))
a |= LPC32XX_I2C_TX_STOP;
/* Send address byte */
writel(a, &i2c->tx);
}
}
while (length) {
/* wait for transmit fifo not full */
stat = readl(&i2c->stat);
if (!(stat & LPC32XX_I2C_STAT_TFF)) {
/* compute data byte, add stop if length==0 */
length--;
int d = *(data++);
if (!length)
d |= LPC32XX_I2C_TX_STOP;
/* Send data byte */
writel(d, &i2c->tx);
}
}
/* wait for end of transation */
while (!((stat = readl(&i2c->stat)) & LPC32XX_I2C_STAT_TDI))
;
/* clear end-of-transaction flag */
writel(1, &i2c->stat);
return 0;
}
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, _i2c_init, lpc32xx_i2c_probe,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
CONFIG_SYS_I2C_LPC32XX_SPEED,
CONFIG_SYS_I2C_LPC32XX_SLAVE,
0)
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, _i2c_init, lpc32xx_i2c_probe,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
CONFIG_SYS_I2C_LPC32XX_SPEED,
CONFIG_SYS_I2C_LPC32XX_SLAVE,
1)
U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, _i2c_init, NULL,
lpc32xx_i2c_read, lpc32xx_i2c_write,
lpc32xx_i2c_set_bus_speed,
100000,
0,
2)
|
