target/linux/s3c24xx/patches/0212-introduce-BANKCON-meddling-sysfs.patch.patch

   1 From 3db422fde610960fdca8bd2a2b882015a62860ca Mon Sep 17 00:00:00 2001
   2 From: Andy Green <andy@openmoko.com>
   3 Date: Fri, 25 Jul 2008 23:06:20 +0100
   4 Subject: [PATCH] introduce-BANKCON-meddling-sysfs.patch
   5
   6 A few questions have been flying around about how optimal
   7 our waitstates are for various things including Glamo.
   8
   9 This patch introduces new sysfs nodes
  10
  11 /sys/devices/platform/neo1973-memconfig.0/BANKCON0
  12 ...
  13 /sys/devices/platform/neo1973-memconfig.0/BANKCON7
  14
  15 If you cat them you get translated info about bus speed on
  16 that chip select, eg,
  17
  18 # cat /sys/devices/platform/neo1973-memconfig.0/BANKCON1
  19 BANKCON1 = 0x00000A40
  20  Type = ROM / SRAM
  21  PMC  = normal (1 data)
  22  Tacp = 2 clocks
  23  Tcah = 0 clocks
  24  Tcoh = 1 clock
  25  Tacc = 3 clocks
  26  Tcos = 1 clock
  27  Tacs = 0 clocks
  28
  29 You can write them in hex too
  30
  31 # echo 0x200 > /sys/devices/platform/neo1973-memconfig.0/BANKCON1
  32
  33 The write format for BANKCON0 - 5 looks like this
  34
  35  b1..b0   PMC  Page Mode Config
  36  b3..b2   Tacp Page Mode Access Cycle
  37  b5..b4   Tcah Address hold after CS deasserted
  38  b7..b6   Tcoh CS hold after OE deasserted
  39  b10..b8  Tacc Access Cycle Period
  40  b12..b11 Tcos CS setup before OE asserted
  41  b14..b13 Tacs Address setup before CS asserted
  42
  43 BANKCON 6 and 7 have two extra bits
  44
  45  b16..b15  MT  Memory type (00=ROM/SRAM, 11=DRAM)
  46
  47 If it's ROM/SRAM, the rest of the bits are as described above.
  48 For DRAM
  49
  50  b1..b0   SCAN Column address number
  51  b3..b2   RAS to CAS delay
  52
  53 The patch is intended to let people experiement on their own.  But
  54 of course you will crash things for sure if the timing is wrong, and
  55 you can also trash SD Card data if you make Glamo unstable, so remove
  56 it or remount ro first.  Other horrible things are possible, but
  57 because the settings aren't sticky, you should always be able to
  58 recover by either normal reboot usually or at worst NOR boot and then
  59 dfu.  Most likely you will just crash your session and have to reboot
  60 if your settings are bad, but consider yourself warned bad things are
  61 possible. :-)
  62
  63 Signed-off-by: Andy Green <andy@openmoko.com>
  64 ---
  65  arch/arm/mach-s3c2440/mach-gta02.c        |    6 +
  66  arch/arm/plat-s3c24xx/Makefile            |    3 +-
  67  arch/arm/plat-s3c24xx/neo1973_memconfig.c |  186 +++++++++++++++++++++++++++++
  68  3 files changed, 194 insertions(+), 1 deletions(-)
  69  create mode 100644 arch/arm/plat-s3c24xx/neo1973_memconfig.c
  70
  71 diff --git a/arch/arm/mach-s3c2440/mach-gta02.c b/arch/arm/mach-s3c2440/mach-gta02.c
  72 index b3d3797..f30abb6 100644
  73 --- a/arch/arm/mach-s3c2440/mach-gta02.c
  74 +++ b/arch/arm/mach-s3c2440/mach-gta02.c
  75 @@ -412,6 +412,11 @@ struct platform_device gta02_resume_reason_device = {
  76         .num_resources  = 0,
  77  };
  78
  79 +struct platform_device gta02_memconfig_device = {
  80 +       .name           = "neo1973-memconfig",
  81 +       .num_resources  = 0,
  82 +};
  83 +
  84  static struct map_desc gta02_iodesc[] __initdata = {
  85         {
  86                 .virtual        = 0xe0000000,
  87 @@ -829,6 +834,7 @@ static struct platform_device *gta02_devices[] __initdata = {
  88         &gta02_nor_flash,
  89         &sc32440_fiq_device,
  90         &gta02_version_device,
  91 +       &gta02_memconfig_device,
  92         &gta02_resume_reason_device,
  93         &s3c24xx_pwm_device,
  94
  95 diff --git a/arch/arm/plat-s3c24xx/Makefile b/arch/arm/plat-s3c24xx/Makefile
  96 index f60dc5f..baae831 100644
  97 --- a/arch/arm/plat-s3c24xx/Makefile
  98 +++ b/arch/arm/plat-s3c24xx/Makefile
  99 @@ -35,4 +35,5 @@ obj-$(CONFIG_MACH_NEO1973)    += neo1973_version.o \
 100                                    neo1973_pm_gps.o \
 101                                    neo1973_pm_bt.o  \
 102                                    neo1973_shadow.o \
 103 -                                  neo1973_pm_resume_reason.o
 104 +                                  neo1973_pm_resume_reason.o \
 105 +                                  neo1973_memconfig.o
 106 diff --git a/arch/arm/plat-s3c24xx/neo1973_memconfig.c b/arch/arm/plat-s3c24xx/neo1973_memconfig.c
 107 new file mode 100644
 108 index 0000000..55d85fc
 109 --- /dev/null
 110 +++ b/arch/arm/plat-s3c24xx/neo1973_memconfig.c
 111 @@ -0,0 +1,186 @@
 112 +/*
 113 + * Memory access timing control sysfs for the s3c24xx based device
 114 + *
 115 + * (C) 2008 by Openmoko Inc.
 116 + * Author: Andy Green <andy@openmoko.com>
 117 + * All rights reserved.
 118 + *
 119 + * This program is free software; you can redistribute it and/or modify
 120 + * it under the terms of the GNU General Public License version 2 as
 121 + * published by the Free Software Foundation
 122 + *
 123 + */
 124 +
 125 +#include <linux/module.h>
 126 +#include <linux/init.h>
 127 +#include <linux/kernel.h>
 128 +#include <linux/platform_device.h>
 129 +
 130 +#include <asm/hardware.h>
 131 +#include <asm/mach-types.h>
 132 +#include <asm/arch/regs-mem.h>
 133 +
 134 +static ssize_t neo1973_memconfig_read(struct device *dev,
 135 +                                      struct device_attribute *attr, char *buf)
 136 +{
 137 +       int index = attr->attr.name[strlen(attr->attr.name) - 1] - '0';
 138 +       u32 reg = *((u32 *)(S3C2410_MEMREG(((index + 1) << 2))));
 139 +       static const char *meaning[][8] = {
 140 +               {
 141 +                       [0] = "normal (1 data)",
 142 +                       [1] = "4 data",
 143 +                       [2] = "8 data",
 144 +                       [3] = "16 data",
 145 +               }, {
 146 +                       [0] = "2 clocks",
 147 +                       [1] = "3 clocks",
 148 +                       [2] = "4 clocks",
 149 +                       [3] = "6 clocks",
 150 +               }, {
 151 +                       [0] = "0 clocks",
 152 +                       [1] = "1 clock",
 153 +                       [2] = "2 clocks",
 154 +                       [3] = "4 clocks",
 155 +               }, {
 156 +                       [0] = "1 clock",
 157 +                       [1] = "2 clocks",
 158 +                       [2] = "3 clocks",
 159 +                       [3] = "4 clocks",
 160 +                       [4] = "6 clocks",
 161 +                       [5] = "8 clocks",
 162 +                       [6] = "10 clocks",
 163 +                       [7] = "14 clocks",
 164 +               }, { /* after this, only for CS6 and CS7 */
 165 +                       [0] = "ROM / SRAM",
 166 +                       [1] = "(illegal)",
 167 +                       [2] = "(illegal)",
 168 +                       [3] = "Sync DRAM",
 169 +               }, {
 170 +                       [0] = "8 Column bits",
 171 +                       [1] = "9 Column bits",
 172 +                       [2] = "10 Column bits",
 173 +                       [3] = "(illegal)",
 174 +               }, {
 175 +                       [0] = "2 clocks",
 176 +                       [1] = "3 clocks",
 177 +                       [2] = "4 clocks",
 178 +                       [3] = "(illegal)",
 179 +               }
 180 +       };
 181 +
 182 +       if (index >= 6)
 183 +               if (((reg >> 15) & 3) == 3) /* DRAM */
 184 +                       return sprintf(buf, "BANKCON%d = 0x%08X\n DRAM:\n"
 185 +                                           "  Trcd = %s\n  SCAN = %s\n", index,
 186 +                                           reg, meaning[5][reg & 3],
 187 +                                           meaning[1][(reg >> 2) & 3]);
 188 +
 189 +       return sprintf(buf, "BANKCON%d = 0x%08X\n Type = %s\n PMC  = %s\n"
 190 +                           " Tacp = %s\n Tcah = %s\n Tcoh = %s\n Tacc = %s\n"
 191 +                           " Tcos = %s\n Tacs = %s\n",
 192 +                           index, reg, meaning[4][(reg >> 15) & 3],
 193 +                           meaning[0][reg & 3],
 194 +                           meaning[1][(reg >> 2) & 3],
 195 +                           meaning[2][(reg >> 4) & 3],
 196 +                           meaning[2][(reg >> 6) & 3],
 197 +                           meaning[3][(reg >> 8) & 7],
 198 +                           meaning[2][(reg >> 11) & 3],
 199 +                           meaning[2][(reg >> 13) & 3]);
 200 +}
 201 +
 202 +static ssize_t neo1973_memconfig_write(struct device *dev,
 203 +                  struct device_attribute *attr, const char *buf, size_t count)
 204 +{
 205 +       int index = attr->attr.name[strlen(attr->attr.name) - 1] - '0';
 206 +       unsigned long val = simple_strtoul(buf, NULL, 16);
 207 +
 208 +       dev_info(dev, "setting BANKCON%d <- 0x%08X\n", index, (u32)val);
 209 +
 210 +       *((u32 *)(S3C2410_MEMREG(((index + 1) << 2)))) = (u32)val;
 211 +
 212 +       return count;
 213 +}
 214 +
 215 +
 216 +static DEVICE_ATTR(BANKCON0, 0644, neo1973_memconfig_read,
 217 +                                                      neo1973_memconfig_write);
 218 +static DEVICE_ATTR(BANKCON1, 0644, neo1973_memconfig_read,
 219 +                                                      neo1973_memconfig_write);
 220 +static DEVICE_ATTR(BANKCON2, 0644, neo1973_memconfig_read,
 221 +                                                      neo1973_memconfig_write);
 222 +static DEVICE_ATTR(BANKCON3, 0644, neo1973_memconfig_read,
 223 +                                                      neo1973_memconfig_write);
 224 +static DEVICE_ATTR(BANKCON4, 0644, neo1973_memconfig_read,
 225 +                                                      neo1973_memconfig_write);
 226 +static DEVICE_ATTR(BANKCON5, 0644, neo1973_memconfig_read,
 227 +                                                      neo1973_memconfig_write);
 228 +static DEVICE_ATTR(BANKCON6, 0644, neo1973_memconfig_read,
 229 +                                                      neo1973_memconfig_write);
 230 +static DEVICE_ATTR(BANKCON7, 0644, neo1973_memconfig_read,
 231 +                                                      neo1973_memconfig_write);
 232 +
 233 +static struct attribute *neo1973_memconfig_sysfs_entries[] = {
 234 +       &dev_attr_BANKCON0.attr,
 235 +       &dev_attr_BANKCON1.attr,
 236 +       &dev_attr_BANKCON2.attr,
 237 +       &dev_attr_BANKCON3.attr,
 238 +       &dev_attr_BANKCON4.attr,
 239 +       &dev_attr_BANKCON5.attr,
 240 +       &dev_attr_BANKCON6.attr,
 241 +       &dev_attr_BANKCON7.attr,
 242 +       NULL
 243 +};
 244 +
 245 +static struct attribute_group neo1973_memconfig_attr_group = {
 246 +       .name   = NULL,
 247 +       .attrs  = neo1973_memconfig_sysfs_entries,
 248 +};
 249 +
 250 +static int __init neo1973_memconfig_probe(struct platform_device *pdev)
 251 +{
 252 +       dev_info(&pdev->dev, "starting\n");
 253 +
 254 +       switch (machine_arch_type) {
 255 +#ifdef CONFIG_MACH_NEO1973_GTA01
 256 +       case MACH_TYPE_NEO1973_GTA01:
 257 +               return -EINVAL;
 258 +#endif /* CONFIG_MACH_NEO1973_GTA01 */
 259 +       default:
 260 +               break;
 261 +       }
 262 +
 263 +       return sysfs_create_group(&pdev->dev.kobj,
 264 +                                                &neo1973_memconfig_attr_group);
 265 +}
 266 +
 267 +static int neo1973_memconfig_remove(struct platform_device *pdev)
 268 +{
 269 +       sysfs_remove_group(&pdev->dev.kobj, &neo1973_memconfig_attr_group);
 270 +       return 0;
 271 +}
 272 +
 273 +static struct platform_driver neo1973_memconfig_driver = {
 274 +       .probe          = neo1973_memconfig_probe,
 275 +       .remove         = neo1973_memconfig_remove,
 276 +       .driver         = {
 277 +               .name           = "neo1973-memconfig",
 278 +       },
 279 +};
 280 +
 281 +static int __devinit neo1973_memconfig_init(void)
 282 +{
 283 +       return platform_driver_register(&neo1973_memconfig_driver);
 284 +}
 285 +
 286 +static void neo1973_memconfig_exit(void)
 287 +{
 288 +       platform_driver_unregister(&neo1973_memconfig_driver);
 289 +}
 290 +
 291 +module_init(neo1973_memconfig_init);
 292 +module_exit(neo1973_memconfig_exit);
 293 +
 294 +MODULE_LICENSE("GPL");
 295 +MODULE_AUTHOR("Andy Green <andy@openmoko.com>");
 296 +MODULE_DESCRIPTION("neo1973 memconfig");
 297 +
 298 --
 299 1.5.6.3
 300