Merge branch 'topic/usb-audio' into for-linus
[linux-2.6] / arch / mips / txx9 / generic / spi_eeprom.c
1 /*
2  * spi_eeprom.c
3  * Copyright (C) 2000-2001 Toshiba Corporation
4  *
5  * 2003-2005 (c) MontaVista Software, Inc. This file is licensed under the
6  * terms of the GNU General Public License version 2. This program is
7  * licensed "as is" without any warranty of any kind, whether express
8  * or implied.
9  *
10  * Support for TX4938 in 2.6 - Manish Lachwani (mlachwani@mvista.com)
11  */
12 #include <linux/init.h>
13 #include <linux/device.h>
14 #include <linux/spi/spi.h>
15 #include <linux/spi/eeprom.h>
16 #include <asm/txx9/spi.h>
17
18 #define AT250X0_PAGE_SIZE       8
19
20 /* register board information for at25 driver */
21 int __init spi_eeprom_register(int busid, int chipid, int size)
22 {
23         struct spi_board_info info = {
24                 .modalias = "at25",
25                 .max_speed_hz = 1500000,        /* 1.5Mbps */
26                 .bus_num = busid,
27                 .chip_select = chipid,
28                 /* Mode 0: High-Active, Sample-Then-Shift */
29         };
30         struct spi_eeprom *eeprom;
31         eeprom = kzalloc(sizeof(*eeprom), GFP_KERNEL);
32         if (!eeprom)
33                 return -ENOMEM;
34         strcpy(eeprom->name, "at250x0");
35         eeprom->byte_len = size;
36         eeprom->page_size = AT250X0_PAGE_SIZE;
37         eeprom->flags = EE_ADDR1;
38         info.platform_data = eeprom;
39         return spi_register_board_info(&info, 1);
40 }
41
42 /* simple temporary spi driver to provide early access to seeprom. */
43
44 static struct read_param {
45         int busid;
46         int chipid;
47         int address;
48         unsigned char *buf;
49         int len;
50 } *read_param;
51
52 static int __init early_seeprom_probe(struct spi_device *spi)
53 {
54         int stat = 0;
55         u8 cmd[2];
56         int len = read_param->len;
57         char *buf = read_param->buf;
58         int address = read_param->address;
59
60         dev_info(&spi->dev, "spiclk %u KHz.\n",
61                  (spi->max_speed_hz + 500) / 1000);
62         if (read_param->busid != spi->master->bus_num ||
63             read_param->chipid != spi->chip_select)
64                 return -ENODEV;
65         while (len > 0) {
66                 /* spi_write_then_read can only work with small chunk */
67                 int c = len < AT250X0_PAGE_SIZE ? len : AT250X0_PAGE_SIZE;
68                 cmd[0] = 0x03;  /* AT25_READ */
69                 cmd[1] = address;
70                 stat = spi_write_then_read(spi, cmd, sizeof(cmd), buf, c);
71                 buf += c;
72                 len -= c;
73                 address += c;
74         }
75         return stat;
76 }
77
78 static struct spi_driver early_seeprom_driver __initdata = {
79         .driver = {
80                 .name   = "at25",
81                 .owner  = THIS_MODULE,
82         },
83         .probe  = early_seeprom_probe,
84 };
85
86 int __init spi_eeprom_read(int busid, int chipid, int address,
87                            unsigned char *buf, int len)
88 {
89         int ret;
90         struct read_param param = {
91                 .busid = busid,
92                 .chipid = chipid,
93                 .address = address,
94                 .buf = buf,
95                 .len = len
96         };
97
98         read_param = &param;
99         ret = spi_register_driver(&early_seeprom_driver);
100         if (!ret)
101                 spi_unregister_driver(&early_seeprom_driver);
102         return ret;
103 }