drivers/mtd/maps/physmap_of_versatile.c

   1 /*
   2  * Versatile OF physmap driver add-on
   3  *
   4  * Copyright (c) 2016, Linaro Limited
   5  * Author: Linus Walleij <linus.walleij@linaro.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22 #include <linux/export.h>
  23 #include <linux/io.h>
  24 #include <linux/of.h>
  25 #include <linux/of_address.h>
  26 #include <linux/of_device.h>
  27 #include <linux/mtd/map.h>
  28 #include <linux/mfd/syscon.h>
  29 #include <linux/regmap.h>
  30 #include <linux/bitops.h>
  31 #include "physmap_of_versatile.h"
  32
  33 static struct regmap *syscon_regmap;
  34
  35 enum versatile_flashprot {
  36         INTEGRATOR_AP_FLASHPROT,
  37         INTEGRATOR_CP_FLASHPROT,
  38         VERSATILE_FLASHPROT,
  39         REALVIEW_FLASHPROT,
  40 };
  41
  42 static const struct of_device_id syscon_match[] = {
  43         {
  44                 .compatible = "arm,integrator-ap-syscon",
  45                 .data = (void *)INTEGRATOR_AP_FLASHPROT,
  46         },
  47         {
  48                 .compatible = "arm,integrator-cp-syscon",
  49                 .data = (void *)INTEGRATOR_CP_FLASHPROT,
  50         },
  51         {
  52                 .compatible = "arm,core-module-versatile",
  53                 .data = (void *)VERSATILE_FLASHPROT,
  54         },
  55         {
  56                 .compatible = "arm,realview-eb-syscon",
  57                 .data = (void *)REALVIEW_FLASHPROT,
  58         },
  59         {
  60                 .compatible = "arm,realview-pb1176-syscon",
  61                 .data = (void *)REALVIEW_FLASHPROT,
  62         },
  63         {
  64                 .compatible = "arm,realview-pb11mp-syscon",
  65                 .data = (void *)REALVIEW_FLASHPROT,
  66         },
  67         {
  68                 .compatible = "arm,realview-pba8-syscon",
  69                 .data = (void *)REALVIEW_FLASHPROT,
  70         },
  71         {
  72                 .compatible = "arm,realview-pbx-syscon",
  73                 .data = (void *)REALVIEW_FLASHPROT,
  74         },
  75         {},
  76 };
  77
  78 /*
  79  * Flash protection handling for the Integrator/AP
  80  */
  81 #define INTEGRATOR_SC_CTRLS_OFFSET      0x08
  82 #define INTEGRATOR_SC_CTRLC_OFFSET      0x0C
  83 #define INTEGRATOR_SC_CTRL_FLVPPEN      BIT(1)
  84 #define INTEGRATOR_SC_CTRL_FLWP         BIT(2)
  85
  86 #define INTEGRATOR_EBI_CSR1_OFFSET      0x04
  87 /* The manual says bit 2, the code says bit 3, trust the code */
  88 #define INTEGRATOR_EBI_WRITE_ENABLE     BIT(3)
  89 #define INTEGRATOR_EBI_LOCK_OFFSET      0x20
  90 #define INTEGRATOR_EBI_LOCK_VAL         0xA05F
  91
  92 static const struct of_device_id ebi_match[] = {
  93         { .compatible = "arm,external-bus-interface"},
  94         { },
  95 };
  96
  97 static int ap_flash_init(struct platform_device *pdev)
  98 {
  99         struct device_node *ebi;
 100         static void __iomem *ebi_base;
 101         u32 val;
 102         int ret;
 103
 104         /* Look up the EBI */
 105         ebi = of_find_matching_node(NULL, ebi_match);
 106         if (!ebi) {
 107                 return -ENODEV;
 108         }
 109         ebi_base = of_iomap(ebi, 0);
 110         if (!ebi_base)
 111                 return -ENODEV;
 112
 113         /* Clear VPP and write protection bits */
 114         ret = regmap_write(syscon_regmap,
 115                 INTEGRATOR_SC_CTRLC_OFFSET,
 116                 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
 117         if (ret)
 118                 dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n");
 119
 120         /* Unlock the EBI */
 121         writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET);
 122
 123         /* Enable write cycles on the EBI, CSR1 (flash) */
 124         val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET);
 125         val |= INTEGRATOR_EBI_WRITE_ENABLE;
 126         writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET);
 127
 128         /* Lock the EBI again */
 129         writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET);
 130         iounmap(ebi_base);
 131
 132         return 0;
 133 }
 134
 135 static void ap_flash_set_vpp(struct map_info *map, int on)
 136 {
 137         int ret;
 138
 139         if (on) {
 140                 ret = regmap_write(syscon_regmap,
 141                         INTEGRATOR_SC_CTRLS_OFFSET,
 142                         INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
 143                 if (ret)
 144                         pr_err("error enabling AP VPP\n");
 145         } else {
 146                 ret = regmap_write(syscon_regmap,
 147                         INTEGRATOR_SC_CTRLC_OFFSET,
 148                         INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP);
 149                 if (ret)
 150                         pr_err("error disabling AP VPP\n");
 151         }
 152 }
 153
 154 /*
 155  * Flash protection handling for the Integrator/CP
 156  */
 157
 158 #define INTCP_FLASHPROG_OFFSET          0x04
 159 #define CINTEGRATOR_FLVPPEN             BIT(0)
 160 #define CINTEGRATOR_FLWREN              BIT(1)
 161 #define CINTEGRATOR_FLMASK              BIT(0)|BIT(1)
 162
 163 static void cp_flash_set_vpp(struct map_info *map, int on)
 164 {
 165         int ret;
 166
 167         if (on) {
 168                 ret = regmap_update_bits(syscon_regmap,
 169                                 INTCP_FLASHPROG_OFFSET,
 170                                 CINTEGRATOR_FLMASK,
 171                                 CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN);
 172                 if (ret)
 173                         pr_err("error setting CP VPP\n");
 174         } else {
 175                 ret = regmap_update_bits(syscon_regmap,
 176                                 INTCP_FLASHPROG_OFFSET,
 177                                 CINTEGRATOR_FLMASK,
 178                                 0);
 179                 if (ret)
 180                         pr_err("error setting CP VPP\n");
 181         }
 182 }
 183
 184 /*
 185  * Flash protection handling for the Versatiles and RealViews
 186  */
 187
 188 #define VERSATILE_SYS_FLASH_OFFSET            0x4C
 189
 190 static void versatile_flash_set_vpp(struct map_info *map, int on)
 191 {
 192         int ret;
 193
 194         ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET,
 195                                  0x01, !!on);
 196         if (ret)
 197                 pr_err("error setting Versatile VPP\n");
 198 }
 199
 200 int of_flash_probe_versatile(struct platform_device *pdev,
 201                              struct device_node *np,
 202                              struct map_info *map)
 203 {
 204         struct device_node *sysnp;
 205         const struct of_device_id *devid;
 206         struct regmap *rmap;
 207         static enum versatile_flashprot versatile_flashprot;
 208         int ret;
 209
 210         /* Not all flash chips use this protection line */
 211         if (!of_device_is_compatible(np, "arm,versatile-flash"))
 212                 return 0;
 213
 214         /* For first chip probed, look up the syscon regmap */
 215         if (!syscon_regmap) {
 216                 sysnp = of_find_matching_node_and_match(NULL,
 217                                                         syscon_match,
 218                                                         &devid);
 219                 if (!sysnp)
 220                         return -ENODEV;
 221
 222                 versatile_flashprot = (enum versatile_flashprot)devid->data;
 223                 rmap = syscon_node_to_regmap(sysnp);
 224                 if (IS_ERR(rmap))
 225                         return PTR_ERR(rmap);
 226
 227                 syscon_regmap = rmap;
 228         }
 229
 230         switch (versatile_flashprot) {
 231         case INTEGRATOR_AP_FLASHPROT:
 232                 ret = ap_flash_init(pdev);
 233                 if (ret)
 234                         return ret;
 235                 map->set_vpp = ap_flash_set_vpp;
 236                 dev_info(&pdev->dev, "Integrator/AP flash protection\n");
 237                 break;
 238         case INTEGRATOR_CP_FLASHPROT:
 239                 map->set_vpp = cp_flash_set_vpp;
 240                 dev_info(&pdev->dev, "Integrator/CP flash protection\n");
 241                 break;
 242         case VERSATILE_FLASHPROT:
 243         case REALVIEW_FLASHPROT:
 244                 map->set_vpp = versatile_flash_set_vpp;
 245                 dev_info(&pdev->dev, "versatile/realview flash protection\n");
 246                 break;
 247         default:
 248                 dev_info(&pdev->dev, "device marked as Versatile flash "
 249                          "but no system controller was found\n");
 250                 break;
 251         }
 252
 253         return 0;
 254 }