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authorRyan Jackson <rjackson@lnxi.com>2006-10-20 17:41:01 -0400
committerDavid Woodhouse <dwmw2@infradead.org>2006-10-21 11:15:43 -0400
commitc9073ce02adfa273a3d6d53eac8c4c035510ad9c (patch)
tree6191b00b2241ff73c6139a7a513b17073e10c46a /drivers/mtd/maps
parent1ef93a0f668c8736cb6b6c3a43a5b8101efa24af (diff)
[MTD] MAPS: Add parameter to amd76xrom to override rom window size
The 2 bits controlling the window size are often set to allow reading the BIOS, but too small to allow writing, since the lock registers are 4MiB lower in the address space than the data. This is intended to prevent flashing the bios, perhaps accidentally. The bits are 6 and 7. If both bits are set, it is a 5MiB window. If only the 7 Bit is set, it is a 4MiB window. Otherwise, it is a 64KiB window. This parameter allows the driver to override the BIOS settings. Signed-off-by: Ryan Jackson <rjackson@lnxi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Diffstat (limited to 'drivers/mtd/maps')
-rw-r--r--drivers/mtd/maps/amd76xrom.c34
1 files changed, 28 insertions, 6 deletions
diff --git a/drivers/mtd/maps/amd76xrom.c b/drivers/mtd/maps/amd76xrom.c
index 797caffb20b1..78b671172bb2 100644
--- a/drivers/mtd/maps/amd76xrom.c
+++ b/drivers/mtd/maps/amd76xrom.c
@@ -7,6 +7,7 @@
7 7
8#include <linux/module.h> 8#include <linux/module.h>
9#include <linux/types.h> 9#include <linux/types.h>
10#include <linux/version.h>
10#include <linux/kernel.h> 11#include <linux/kernel.h>
11#include <linux/init.h> 12#include <linux/init.h>
12#include <asm/io.h> 13#include <asm/io.h>
@@ -44,6 +45,23 @@ struct amd76xrom_map_info {
44 char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN]; 45 char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
45}; 46};
46 47
48/* The 2 bits controlling the window size are often set to allow reading
49 * the BIOS, but too small to allow writing, since the lock registers are
50 * 4MiB lower in the address space than the data.
51 *
52 * This is intended to prevent flashing the bios, perhaps accidentally.
53 *
54 * This parameter allows the normal driver to over-ride the BIOS settings.
55 *
56 * The bits are 6 and 7. If both bits are set, it is a 5MiB window.
57 * If only the 7 Bit is set, it is a 4MiB window. Otherwise, a
58 * 64KiB window.
59 *
60 */
61static uint win_size_bits;
62module_param(win_size_bits, uint, 0);
63MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
64
47static struct amd76xrom_window amd76xrom_window = { 65static struct amd76xrom_window amd76xrom_window = {
48 .maps = LIST_HEAD_INIT(amd76xrom_window.maps), 66 .maps = LIST_HEAD_INIT(amd76xrom_window.maps),
49}; 67};
@@ -95,6 +113,16 @@ static int __devinit amd76xrom_init_one (struct pci_dev *pdev,
95 /* Remember the pci dev I find the window in - already have a ref */ 113 /* Remember the pci dev I find the window in - already have a ref */
96 window->pdev = pdev; 114 window->pdev = pdev;
97 115
116 /* Enable the selected rom window. This is often incorrectly
117 * set up by the BIOS, and the 4MiB offset for the lock registers
118 * requires the full 5MiB of window space.
119 *
120 * This 'write, then read' approach leaves the bits for
121 * other uses of the hardware info.
122 */
123 pci_read_config_byte(pdev, 0x43, &byte);
124 pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
125
98 /* Assume the rom window is properly setup, and find it's size */ 126 /* Assume the rom window is properly setup, and find it's size */
99 pci_read_config_byte(pdev, 0x43, &byte); 127 pci_read_config_byte(pdev, 0x43, &byte);
100 if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) { 128 if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
@@ -129,12 +157,6 @@ static int __devinit amd76xrom_init_one (struct pci_dev *pdev,
129 (unsigned long long)window->rsrc.end); 157 (unsigned long long)window->rsrc.end);
130 } 158 }
131 159
132#if 0
133
134 /* Enable the selected rom window */
135 pci_read_config_byte(pdev, 0x43, &byte);
136 pci_write_config_byte(pdev, 0x43, byte | rwindow->segen_bits);
137#endif
138 160
139 /* Enable writes through the rom window */ 161 /* Enable writes through the rom window */
140 pci_read_config_byte(pdev, 0x40, &byte); 162 pci_read_config_byte(pdev, 0x40, &byte);