1/*
2 * Bootloader version of the i2c driver for the MV64x60.
3 *
4 * Author: Dale Farnsworth <dfarnsworth@mvista.com>
5 * Maintained by: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2003, 2007 (c) MontaVista, Software, Inc.  This file is licensed under
8 * the terms of the GNU General Public License version 2.  This program is
9 * licensed "as is" without any warranty of any kind, whether express or
10 * implied.
11 */
12
13#include <stdarg.h>
14#include <stddef.h>
15#include "types.h"
16#include "elf.h"
17#include "page.h"
18#include "string.h"
19#include "stdio.h"
20#include "io.h"
21#include "ops.h"
22#include "mv64x60.h"
23
24extern void udelay(long);
25
26/* Register defines */
27#define MV64x60_I2C_REG_SLAVE_ADDR			0x00
28#define MV64x60_I2C_REG_DATA				0x04
29#define MV64x60_I2C_REG_CONTROL				0x08
30#define MV64x60_I2C_REG_STATUS				0x0c
31#define MV64x60_I2C_REG_BAUD				0x0c
32#define MV64x60_I2C_REG_EXT_SLAVE_ADDR			0x10
33#define MV64x60_I2C_REG_SOFT_RESET			0x1c
34
35#define MV64x60_I2C_CONTROL_ACK				0x04
36#define MV64x60_I2C_CONTROL_IFLG			0x08
37#define MV64x60_I2C_CONTROL_STOP			0x10
38#define MV64x60_I2C_CONTROL_START			0x20
39#define MV64x60_I2C_CONTROL_TWSIEN			0x40
40#define MV64x60_I2C_CONTROL_INTEN			0x80
41
42#define MV64x60_I2C_STATUS_BUS_ERR			0x00
43#define MV64x60_I2C_STATUS_MAST_START			0x08
44#define MV64x60_I2C_STATUS_MAST_REPEAT_START		0x10
45#define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK		0x18
46#define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK		0x20
47#define MV64x60_I2C_STATUS_MAST_WR_ACK			0x28
48#define MV64x60_I2C_STATUS_MAST_WR_NO_ACK		0x30
49#define MV64x60_I2C_STATUS_MAST_LOST_ARB		0x38
50#define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK		0x40
51#define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK		0x48
52#define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK		0x50
53#define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK		0x58
54#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK		0xd0
55#define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK	0xd8
56#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK		0xe0
57#define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK	0xe8
58#define MV64x60_I2C_STATUS_NO_STATUS			0xf8
59
60static u8 *ctlr_base;
61
62static int mv64x60_i2c_wait_for_status(int wanted)
63{
64	int i;
65	int status;
66
67	for (i=0; i<1000; i++) {
68		udelay(10);
69		status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS))
70			& 0xff;
71		if (status == wanted)
72			return status;
73	}
74	return -status;
75}
76
77static int mv64x60_i2c_control(int control, int status)
78{
79	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
80	return mv64x60_i2c_wait_for_status(status);
81}
82
83static int mv64x60_i2c_read_byte(int control, int status)
84{
85	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
86	if (mv64x60_i2c_wait_for_status(status) < 0)
87		return -1;
88	return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff;
89}
90
91static int mv64x60_i2c_write_byte(int data, int control, int status)
92{
93	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff);
94	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
95	return mv64x60_i2c_wait_for_status(status);
96}
97
98int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size,
99		 u32 count)
100{
101	int i;
102	int data;
103	int control;
104	int status;
105
106	if (ctlr_base == NULL)
107		return -1;
108
109	/* send reset */
110	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0);
111	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0);
112	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0);
113	out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4);
114
115	if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN,
116				MV64x60_I2C_STATUS_NO_STATUS) < 0)
117		return -1;
118
119	/* send start */
120	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
121	status = MV64x60_I2C_STATUS_MAST_START;
122	if (mv64x60_i2c_control(control, status) < 0)
123		return -1;
124
125	/* select device for writing */
126	data = devaddr & ~0x1;
127	control = MV64x60_I2C_CONTROL_TWSIEN;
128	status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK;
129	if (mv64x60_i2c_write_byte(data, control, status) < 0)
130		return -1;
131
132	/* send offset of data */
133	control = MV64x60_I2C_CONTROL_TWSIEN;
134	status = MV64x60_I2C_STATUS_MAST_WR_ACK;
135	if (offset_size > 1) {
136		if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0)
137			return -1;
138	}
139	if (mv64x60_i2c_write_byte(offset, control, status) < 0)
140		return -1;
141
142	/* resend start */
143	control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
144	status = MV64x60_I2C_STATUS_MAST_REPEAT_START;
145	if (mv64x60_i2c_control(control, status) < 0)
146		return -1;
147
148	/* select device for reading */
149	data = devaddr | 0x1;
150	control = MV64x60_I2C_CONTROL_TWSIEN;
151	status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK;
152	if (mv64x60_i2c_write_byte(data, control, status) < 0)
153		return -1;
154
155	/* read all but last byte of data */
156	control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN;
157	status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK;
158
159	for (i=1; i<count; i++) {
160		data = mv64x60_i2c_read_byte(control, status);
161		if (data < 0) {
162			printf("errors on iteration %d\n", i);
163			return -1;
164		}
165		*buf++ = data;
166	}
167
168	/* read last byte of data */
169	control = MV64x60_I2C_CONTROL_TWSIEN;
170	status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK;
171	data = mv64x60_i2c_read_byte(control, status);
172	if (data < 0)
173		return -1;
174	*buf++ = data;
175
176	/* send stop */
177	control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN;
178	status = MV64x60_I2C_STATUS_NO_STATUS;
179	if (mv64x60_i2c_control(control, status) < 0)
180		return -1;
181
182	return count;
183}
184
185int mv64x60_i2c_open(void)
186{
187	u32 v;
188	void *devp;
189
190	devp = finddevice("/mv64x60/i2c");
191	if (devp == NULL)
192		goto err_out;
193	if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
194		goto err_out;
195
196	ctlr_base = (u8 *)v;
197	return 0;
198
199err_out:
200	return -1;
201}
202
203void mv64x60_i2c_close(void)
204{
205	ctlr_base = NULL;
206}
207