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Marek Vasutf4f680a2011-11-08 23:18:12 +00001/*
2 * Freescale i.MX28 I2C Driver
3 *
4 * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
5 * on behalf of DENX Software Engineering GmbH
6 *
7 * Partly based on Linux kernel i2c-mxs.c driver:
8 * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
9 *
10 * Which was based on a (non-working) driver which was:
11 * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 *
27 */
28
29#include <common.h>
30#include <malloc.h>
31#include <asm/errno.h>
32#include <asm/io.h>
33#include <asm/arch/clock.h>
34#include <asm/arch/imx-regs.h>
35#include <asm/arch/sys_proto.h>
36
37#define MXS_I2C_MAX_TIMEOUT 1000000
38
39void mxs_i2c_reset(void)
40{
Otavio Salvador9c471142012-08-05 09:05:31 +000041 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +000042 int ret;
43
Otavio Salvadorfa7a51c2012-08-13 09:53:12 +000044 ret = mxs_reset_block(&i2c_regs->hw_i2c_ctrl0_reg);
Marek Vasutf4f680a2011-11-08 23:18:12 +000045 if (ret) {
46 debug("MXS I2C: Block reset timeout\n");
47 return;
48 }
49
50 writel(I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | I2C_CTRL1_NO_SLAVE_ACK_IRQ |
51 I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
52 I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ,
53 &i2c_regs->hw_i2c_ctrl1_clr);
54
55 writel(I2C_QUEUECTRL_PIO_QUEUE_MODE, &i2c_regs->hw_i2c_queuectrl_set);
56}
57
58void mxs_i2c_setup_read(uint8_t chip, int len)
59{
Otavio Salvador9c471142012-08-05 09:05:31 +000060 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +000061
62 writel(I2C_QUEUECMD_RETAIN_CLOCK | I2C_QUEUECMD_PRE_SEND_START |
63 I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
64 (1 << I2C_QUEUECMD_XFER_COUNT_OFFSET),
65 &i2c_regs->hw_i2c_queuecmd);
66
67 writel((chip << 1) | 1, &i2c_regs->hw_i2c_data);
68
69 writel(I2C_QUEUECMD_SEND_NAK_ON_LAST | I2C_QUEUECMD_MASTER_MODE |
70 (len << I2C_QUEUECMD_XFER_COUNT_OFFSET) |
71 I2C_QUEUECMD_POST_SEND_STOP, &i2c_regs->hw_i2c_queuecmd);
72
73 writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
74}
75
76void mxs_i2c_write(uchar chip, uint addr, int alen,
77 uchar *buf, int blen, int stop)
78{
Otavio Salvador9c471142012-08-05 09:05:31 +000079 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +000080 uint32_t data;
81 int i, remain, off;
82
83 if ((alen > 4) || (alen == 0)) {
84 debug("MXS I2C: Invalid address length\n");
85 return;
86 }
87
88 if (stop)
89 stop = I2C_QUEUECMD_POST_SEND_STOP;
90
91 writel(I2C_QUEUECMD_PRE_SEND_START |
92 I2C_QUEUECMD_MASTER_MODE | I2C_QUEUECMD_DIRECTION |
93 ((blen + alen + 1) << I2C_QUEUECMD_XFER_COUNT_OFFSET) | stop,
94 &i2c_regs->hw_i2c_queuecmd);
95
96 data = (chip << 1) << 24;
97
98 for (i = 0; i < alen; i++) {
99 data >>= 8;
Torsten Fleischerfa86d1c2012-04-17 05:37:45 +0000100 data |= ((char *)&addr)[alen - i - 1] << 24;
Marek Vasutf4f680a2011-11-08 23:18:12 +0000101 if ((i & 3) == 2)
102 writel(data, &i2c_regs->hw_i2c_data);
103 }
104
105 off = i;
106 for (; i < off + blen; i++) {
107 data >>= 8;
108 data |= buf[i - off] << 24;
109 if ((i & 3) == 2)
110 writel(data, &i2c_regs->hw_i2c_data);
111 }
112
113 remain = 24 - ((i & 3) * 8);
114 if (remain)
115 writel(data >> remain, &i2c_regs->hw_i2c_data);
116
117 writel(I2C_QUEUECTRL_QUEUE_RUN, &i2c_regs->hw_i2c_queuectrl_set);
118}
119
120int mxs_i2c_wait_for_ack(void)
121{
Otavio Salvador9c471142012-08-05 09:05:31 +0000122 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +0000123 uint32_t tmp;
124 int timeout = MXS_I2C_MAX_TIMEOUT;
125
126 for (;;) {
127 tmp = readl(&i2c_regs->hw_i2c_ctrl1);
128 if (tmp & I2C_CTRL1_NO_SLAVE_ACK_IRQ) {
129 debug("MXS I2C: No slave ACK\n");
130 goto err;
131 }
132
133 if (tmp & (
134 I2C_CTRL1_EARLY_TERM_IRQ | I2C_CTRL1_MASTER_LOSS_IRQ |
135 I2C_CTRL1_SLAVE_STOP_IRQ | I2C_CTRL1_SLAVE_IRQ)) {
136 debug("MXS I2C: Error (CTRL1 = %08x)\n", tmp);
137 goto err;
138 }
139
140 if (tmp & I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ)
141 break;
142
143 if (!timeout--) {
144 debug("MXS I2C: Operation timed out\n");
145 goto err;
146 }
147
148 udelay(1);
149 }
150
151 return 0;
152
153err:
154 mxs_i2c_reset();
155 return 1;
156}
157
158int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
159{
Otavio Salvador9c471142012-08-05 09:05:31 +0000160 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +0000161 uint32_t tmp = 0;
162 int ret;
163 int i;
164
165 mxs_i2c_write(chip, addr, alen, NULL, 0, 0);
166 ret = mxs_i2c_wait_for_ack();
167 if (ret) {
168 debug("MXS I2C: Failed writing address\n");
169 return ret;
170 }
171
172 mxs_i2c_setup_read(chip, len);
173 ret = mxs_i2c_wait_for_ack();
174 if (ret) {
175 debug("MXS I2C: Failed reading address\n");
176 return ret;
177 }
178
179 for (i = 0; i < len; i++) {
180 if (!(i & 3)) {
181 while (readl(&i2c_regs->hw_i2c_queuestat) &
182 I2C_QUEUESTAT_RD_QUEUE_EMPTY)
183 ;
184 tmp = readl(&i2c_regs->hw_i2c_queuedata);
185 }
186 buffer[i] = tmp & 0xff;
187 tmp >>= 8;
188 }
189
190 return 0;
191}
192
193int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
194{
195 int ret;
196 mxs_i2c_write(chip, addr, alen, buffer, len, 1);
197 ret = mxs_i2c_wait_for_ack();
198 if (ret)
199 debug("MXS I2C: Failed writing address\n");
200
201 return ret;
202}
203
204int i2c_probe(uchar chip)
205{
206 int ret;
207 mxs_i2c_write(chip, 0, 1, NULL, 0, 1);
208 ret = mxs_i2c_wait_for_ack();
209 mxs_i2c_reset();
210 return ret;
211}
212
213void i2c_init(int speed, int slaveadd)
214{
Otavio Salvador9c471142012-08-05 09:05:31 +0000215 struct mxs_i2c_regs *i2c_regs = (struct mxs_i2c_regs *)MXS_I2C0_BASE;
Marek Vasutf4f680a2011-11-08 23:18:12 +0000216
217 mxs_i2c_reset();
218
219 switch (speed) {
220 case 100000:
221 writel((0x0078 << I2C_TIMING0_HIGH_COUNT_OFFSET) |
222 (0x0030 << I2C_TIMING0_RCV_COUNT_OFFSET),
223 &i2c_regs->hw_i2c_timing0);
224 writel((0x0080 << I2C_TIMING1_LOW_COUNT_OFFSET) |
225 (0x0030 << I2C_TIMING1_XMIT_COUNT_OFFSET),
226 &i2c_regs->hw_i2c_timing1);
227 break;
228 case 400000:
229 writel((0x000f << I2C_TIMING0_HIGH_COUNT_OFFSET) |
230 (0x0007 << I2C_TIMING0_RCV_COUNT_OFFSET),
231 &i2c_regs->hw_i2c_timing0);
232 writel((0x001f << I2C_TIMING1_LOW_COUNT_OFFSET) |
233 (0x000f << I2C_TIMING1_XMIT_COUNT_OFFSET),
234 &i2c_regs->hw_i2c_timing1);
235 break;
236 default:
237 printf("MXS I2C: Invalid speed selected (%d Hz)\n", speed);
238 return;
239 }
240
241 writel((0x0015 << I2C_TIMING2_BUS_FREE_OFFSET) |
242 (0x000d << I2C_TIMING2_LEADIN_COUNT_OFFSET),
243 &i2c_regs->hw_i2c_timing2);
244
245 return;
246}