Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6] / arch / powerpc / boot / mv64x60_i2c.c
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
24 /* Register defines */
25 #define MV64x60_I2C_REG_SLAVE_ADDR                      0x00
26 #define MV64x60_I2C_REG_DATA                            0x04
27 #define MV64x60_I2C_REG_CONTROL                         0x08
28 #define MV64x60_I2C_REG_STATUS                          0x0c
29 #define MV64x60_I2C_REG_BAUD                            0x0c
30 #define MV64x60_I2C_REG_EXT_SLAVE_ADDR                  0x10
31 #define MV64x60_I2C_REG_SOFT_RESET                      0x1c
32
33 #define MV64x60_I2C_CONTROL_ACK                         0x04
34 #define MV64x60_I2C_CONTROL_IFLG                        0x08
35 #define MV64x60_I2C_CONTROL_STOP                        0x10
36 #define MV64x60_I2C_CONTROL_START                       0x20
37 #define MV64x60_I2C_CONTROL_TWSIEN                      0x40
38 #define MV64x60_I2C_CONTROL_INTEN                       0x80
39
40 #define MV64x60_I2C_STATUS_BUS_ERR                      0x00
41 #define MV64x60_I2C_STATUS_MAST_START                   0x08
42 #define MV64x60_I2C_STATUS_MAST_REPEAT_START            0x10
43 #define MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK             0x18
44 #define MV64x60_I2C_STATUS_MAST_WR_ADDR_NO_ACK          0x20
45 #define MV64x60_I2C_STATUS_MAST_WR_ACK                  0x28
46 #define MV64x60_I2C_STATUS_MAST_WR_NO_ACK               0x30
47 #define MV64x60_I2C_STATUS_MAST_LOST_ARB                0x38
48 #define MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK             0x40
49 #define MV64x60_I2C_STATUS_MAST_RD_ADDR_NO_ACK          0x48
50 #define MV64x60_I2C_STATUS_MAST_RD_DATA_ACK             0x50
51 #define MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK          0x58
52 #define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_ACK           0xd0
53 #define MV64x60_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK        0xd8
54 #define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_ACK           0xe0
55 #define MV64x60_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK        0xe8
56 #define MV64x60_I2C_STATUS_NO_STATUS                    0xf8
57
58 static u8 *ctlr_base;
59
60 static int mv64x60_i2c_wait_for_status(int wanted)
61 {
62         int i;
63         int status;
64
65         for (i=0; i<1000; i++) {
66                 udelay(10);
67                 status = in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_STATUS))
68                         & 0xff;
69                 if (status == wanted)
70                         return status;
71         }
72         return -status;
73 }
74
75 static int mv64x60_i2c_control(int control, int status)
76 {
77         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
78         return mv64x60_i2c_wait_for_status(status);
79 }
80
81 static int mv64x60_i2c_read_byte(int control, int status)
82 {
83         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
84         if (mv64x60_i2c_wait_for_status(status) < 0)
85                 return -1;
86         return in_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA)) & 0xff;
87 }
88
89 static int mv64x60_i2c_write_byte(int data, int control, int status)
90 {
91         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_DATA), data & 0xff);
92         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_CONTROL), control & 0xff);
93         return mv64x60_i2c_wait_for_status(status);
94 }
95
96 int mv64x60_i2c_read(u32 devaddr, u8 *buf, u32 offset, u32 offset_size,
97                  u32 count)
98 {
99         int i;
100         int data;
101         int control;
102         int status;
103
104         if (ctlr_base == NULL)
105                 return -1;
106
107         /* send reset */
108         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SOFT_RESET), 0);
109         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_SLAVE_ADDR), 0);
110         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_EXT_SLAVE_ADDR), 0);
111         out_le32((u32 *)(ctlr_base + MV64x60_I2C_REG_BAUD), (4 << 3) | 0x4);
112
113         if (mv64x60_i2c_control(MV64x60_I2C_CONTROL_TWSIEN,
114                                 MV64x60_I2C_STATUS_NO_STATUS) < 0)
115                 return -1;
116
117         /* send start */
118         control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
119         status = MV64x60_I2C_STATUS_MAST_START;
120         if (mv64x60_i2c_control(control, status) < 0)
121                 return -1;
122
123         /* select device for writing */
124         data = devaddr & ~0x1;
125         control = MV64x60_I2C_CONTROL_TWSIEN;
126         status = MV64x60_I2C_STATUS_MAST_WR_ADDR_ACK;
127         if (mv64x60_i2c_write_byte(data, control, status) < 0)
128                 return -1;
129
130         /* send offset of data */
131         control = MV64x60_I2C_CONTROL_TWSIEN;
132         status = MV64x60_I2C_STATUS_MAST_WR_ACK;
133         if (offset_size > 1) {
134                 if (mv64x60_i2c_write_byte(offset >> 8, control, status) < 0)
135                         return -1;
136         }
137         if (mv64x60_i2c_write_byte(offset, control, status) < 0)
138                 return -1;
139
140         /* resend start */
141         control = MV64x60_I2C_CONTROL_START | MV64x60_I2C_CONTROL_TWSIEN;
142         status = MV64x60_I2C_STATUS_MAST_REPEAT_START;
143         if (mv64x60_i2c_control(control, status) < 0)
144                 return -1;
145
146         /* select device for reading */
147         data = devaddr | 0x1;
148         control = MV64x60_I2C_CONTROL_TWSIEN;
149         status = MV64x60_I2C_STATUS_MAST_RD_ADDR_ACK;
150         if (mv64x60_i2c_write_byte(data, control, status) < 0)
151                 return -1;
152
153         /* read all but last byte of data */
154         control = MV64x60_I2C_CONTROL_ACK | MV64x60_I2C_CONTROL_TWSIEN;
155         status = MV64x60_I2C_STATUS_MAST_RD_DATA_ACK;
156
157         for (i=1; i<count; i++) {
158                 data = mv64x60_i2c_read_byte(control, status);
159                 if (data < 0) {
160                         printf("errors on iteration %d\n", i);
161                         return -1;
162                 }
163                 *buf++ = data;
164         }
165
166         /* read last byte of data */
167         control = MV64x60_I2C_CONTROL_TWSIEN;
168         status = MV64x60_I2C_STATUS_MAST_RD_DATA_NO_ACK;
169         data = mv64x60_i2c_read_byte(control, status);
170         if (data < 0)
171                 return -1;
172         *buf++ = data;
173
174         /* send stop */
175         control = MV64x60_I2C_CONTROL_STOP | MV64x60_I2C_CONTROL_TWSIEN;
176         status = MV64x60_I2C_STATUS_NO_STATUS;
177         if (mv64x60_i2c_control(control, status) < 0)
178                 return -1;
179
180         return count;
181 }
182
183 int mv64x60_i2c_open(void)
184 {
185         u32 v;
186         void *devp;
187
188         devp = finddevice("/mv64x60/i2c");
189         if (devp == NULL)
190                 goto err_out;
191         if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
192                 goto err_out;
193
194         ctlr_base = (u8 *)v;
195         return 0;
196
197 err_out:
198         return -1;
199 }
200
201 void mv64x60_i2c_close(void)
202 {
203         ctlr_base = NULL;
204 }