1 /* 2 * Copyright (c) 2001, 2003 Maciej W. Rozycki 3 * 4 * DEC MS02-NV (54-20948-01) battery backed-up NVRAM module for 5 * DECstation/DECsystem 5000/2x0 and DECsystem 5900 and 5900/260 6 * systems. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * $Id: ms02-nv.h,v 1.3 2003/08/19 09:25:36 dwmw2 Exp $ 14 */ 15 16 #include <linux/ioport.h> 17 #include <linux/mtd/mtd.h> 18 19 /* 20 * Addresses are decoded as follows: 21 * 22 * 0x000000 - 0x3fffff SRAM 23 * 0x400000 - 0x7fffff CSR 24 * 25 * Within the SRAM area the following ranges are forced by the system 26 * firmware: 27 * 28 * 0x000000 - 0x0003ff diagnostic area, destroyed upon a reboot 29 * 0x000400 - ENDofRAM storage area, available to operating systems 30 * 31 * but we can't really use the available area right from 0x000400 as 32 * the first word is used by the firmware as a status flag passed 33 * from an operating system. If anything but the valid data magic 34 * ID value is found, the firmware considers the SRAM clean, i.e. 35 * containing no valid data, and disables the battery resulting in 36 * data being erased as soon as power is switched off. So the choice 37 * for the start address of the user-available is 0x001000 which is 38 * nicely page aligned. The area between 0x000404 and 0x000fff may 39 * be used by the driver for own needs. 40 * 41 * The diagnostic area defines two status words to be read by an 42 * operating system, a magic ID to distinguish a MS02-NV board from 43 * anything else and a status information providing results of tests 44 * as well as the size of SRAM available, which can be 1MiB or 2MiB 45 * (that's what the firmware handles; no idea if 2MiB modules ever 46 * existed). 47 * 48 * The firmware only handles the MS02-NV board if installed in the 49 * last (15th) slot, so for any other location the status information 50 * stored in the SRAM cannot be relied upon. But from the hardware 51 * point of view there is no problem using up to 14 such boards in a 52 * system -- only the 1st slot needs to be filled with a DRAM module. 53 * The MS02-NV board is ECC-protected, like other MS02 memory boards. 54 * 55 * The state of the battery as provided by the CSR is reflected on 56 * the two onboard LEDs. When facing the battery side of the board, 57 * with the LEDs at the top left and the battery at the bottom right 58 * (i.e. looking from the back side of the system box), their meaning 59 * is as follows (the system has to be powered on): 60 * 61 * left LED battery disable status: lit = enabled 62 * right LED battery condition status: lit = OK 63 */ 64 65 /* MS02-NV iomem register offsets. */ 66 #define MS02NV_CSR 0x400000 /* control & status register */ 67 68 /* MS02-NV CSR status bits. */ 69 #define MS02NV_CSR_BATT_OK 0x01 /* battery OK */ 70 #define MS02NV_CSR_BATT_OFF 0x02 /* battery disabled */ 71 72 73 /* MS02-NV memory offsets. */ 74 #define MS02NV_DIAG 0x0003f8 /* diagnostic status */ 75 #define MS02NV_MAGIC 0x0003fc /* MS02-NV magic ID */ 76 #define MS02NV_VALID 0x000400 /* valid data magic ID */ 77 #define MS02NV_RAM 0x001000 /* user-exposed RAM start */ 78 79 /* MS02-NV diagnostic status bits. */ 80 #define MS02NV_DIAG_TEST 0x01 /* SRAM test done (?) */ 81 #define MS02NV_DIAG_RO 0x02 /* SRAM r/o test done */ 82 #define MS02NV_DIAG_RW 0x04 /* SRAM r/w test done */ 83 #define MS02NV_DIAG_FAIL 0x08 /* SRAM test failed */ 84 #define MS02NV_DIAG_SIZE_MASK 0xf0 /* SRAM size mask */ 85 #define MS02NV_DIAG_SIZE_SHIFT 0x10 /* SRAM size shift (left) */ 86 87 /* MS02-NV general constants. */ 88 #define MS02NV_ID 0x03021966 /* MS02-NV magic ID value */ 89 #define MS02NV_VALID_ID 0xbd100248 /* valid data magic ID value */ 90 #define MS02NV_SLOT_SIZE 0x800000 /* size of the address space 91 decoded by the module */ 92 93 94 typedef volatile u32 ms02nv_uint; 95 96 struct ms02nv_private { 97 struct mtd_info *next; 98 struct { 99 struct resource *module; 100 struct resource *diag_ram; 101 struct resource *user_ram; 102 struct resource *csr; 103 } resource; 104 u_char *addr; 105 size_t size; 106 u_char *uaddr; 107 }; 108