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-rw-r--r--arch/mips/txx9/generic/spi_eeprom.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/mips/txx9/generic/spi_eeprom.c b/arch/mips/txx9/generic/spi_eeprom.c
new file mode 100644
index 000000000000..75c347238f47
--- /dev/null
+++ b/arch/mips/txx9/generic/spi_eeprom.c
@@ -0,0 +1,103 @@
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 */
21int __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
44static struct read_param {
45 int busid;
46 int chipid;
47 int address;
48 unsigned char *buf;
49 int len;
50} *read_param;
51
52static 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
78static struct spi_driver early_seeprom_driver __initdata = {
79 .driver = {
80 .name = "at25",
81 .owner = THIS_MODULE,
82 },
83 .probe = early_seeprom_probe,
84};
85
86int __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}