kernel/drivers/memory/pl172.c

   1 /*
   2  * Memory controller driver for ARM PrimeCell PL172
   3  * PrimeCell MultiPort Memory Controller (PL172)
   4  *
   5  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
   6  *
   7  * Based on:
   8  * TI AEMIF driver, Copyright (C) 2010 - 2013 Texas Instruments Inc.
   9  *
  10  * This file is licensed under the terms of the GNU General Public
  11  * License version 2. This program is licensed "as is" without any
  12  * warranty of any kind, whether express or implied.
  13  */
  14
  15 #include <linux/amba/bus.h>
  16 #include <linux/clk.h>
  17 #include <linux/device.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/io.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/of.h>
  24 #include <linux/of_platform.h>
  25 #include <linux/time.h>
  26
  27 #define MPMC_STATIC_CFG(n)              (0x200 + 0x20 * n)
  28 #define  MPMC_STATIC_CFG_MW_8BIT        0x0
  29 #define  MPMC_STATIC_CFG_MW_16BIT       0x1
  30 #define  MPMC_STATIC_CFG_MW_32BIT       0x2
  31 #define  MPMC_STATIC_CFG_PM             BIT(3)
  32 #define  MPMC_STATIC_CFG_PC             BIT(6)
  33 #define  MPMC_STATIC_CFG_PB             BIT(7)
  34 #define  MPMC_STATIC_CFG_EW             BIT(8)
  35 #define  MPMC_STATIC_CFG_B              BIT(19)
  36 #define  MPMC_STATIC_CFG_P              BIT(20)
  37 #define MPMC_STATIC_WAIT_WEN(n)         (0x204 + 0x20 * n)
  38 #define  MPMC_STATIC_WAIT_WEN_MAX       0x0f
  39 #define MPMC_STATIC_WAIT_OEN(n)         (0x208 + 0x20 * n)
  40 #define  MPMC_STATIC_WAIT_OEN_MAX       0x0f
  41 #define MPMC_STATIC_WAIT_RD(n)          (0x20c + 0x20 * n)
  42 #define  MPMC_STATIC_WAIT_RD_MAX        0x1f
  43 #define MPMC_STATIC_WAIT_PAGE(n)        (0x210 + 0x20 * n)
  44 #define  MPMC_STATIC_WAIT_PAGE_MAX      0x1f
  45 #define MPMC_STATIC_WAIT_WR(n)          (0x214 + 0x20 * n)
  46 #define  MPMC_STATIC_WAIT_WR_MAX        0x1f
  47 #define MPMC_STATIC_WAIT_TURN(n)        (0x218 + 0x20 * n)
  48 #define  MPMC_STATIC_WAIT_TURN_MAX      0x0f
  49
  50 /* Maximum number of static chip selects */
  51 #define PL172_MAX_CS            4
  52
  53 struct pl172_data {
  54         void __iomem *base;
  55         unsigned long rate;
  56         struct clk *clk;
  57 };
  58
  59 static int pl172_timing_prop(struct amba_device *adev,
  60                              const struct device_node *np, const char *name,
  61                              u32 reg_offset, u32 max, int start)
  62 {
  63         struct pl172_data *pl172 = amba_get_drvdata(adev);
  64         int cycles;
  65         u32 val;
  66
  67         if (!of_property_read_u32(np, name, &val)) {
  68                 cycles = DIV_ROUND_UP(val * pl172->rate, NSEC_PER_MSEC) - start;
  69                 if (cycles < 0) {
  70                         cycles = 0;
  71                 } else if (cycles > max) {
  72                         dev_err(&adev->dev, "%s timing too tight\n", name);
  73                         return -EINVAL;
  74                 }
  75
  76                 writel(cycles, pl172->base + reg_offset);
  77         }
  78
  79         dev_dbg(&adev->dev, "%s: %u cycle(s)\n", name, start +
  80                                 readl(pl172->base + reg_offset));
  81
  82         return 0;
  83 }
  84
  85 static int pl172_setup_static(struct amba_device *adev,
  86                               struct device_node *np, u32 cs)
  87 {
  88         struct pl172_data *pl172 = amba_get_drvdata(adev);
  89         u32 cfg;
  90         int ret;
  91
  92         /* MPMC static memory configuration */
  93         if (!of_property_read_u32(np, "mpmc,memory-width", &cfg)) {
  94                 if (cfg == 8) {
  95                         cfg = MPMC_STATIC_CFG_MW_8BIT;
  96                 } else if (cfg == 16) {
  97                         cfg = MPMC_STATIC_CFG_MW_16BIT;
  98                 } else if (cfg == 32) {
  99                         cfg = MPMC_STATIC_CFG_MW_32BIT;
 100                 } else {
 101                         dev_err(&adev->dev, "invalid memory width cs%u\n", cs);
 102                         return -EINVAL;
 103                 }
 104         } else {
 105                 dev_err(&adev->dev, "memory-width property required\n");
 106                 return -EINVAL;
 107         }
 108
 109         if (of_property_read_bool(np, "mpmc,async-page-mode"))
 110                 cfg |= MPMC_STATIC_CFG_PM;
 111
 112         if (of_property_read_bool(np, "mpmc,cs-active-high"))
 113                 cfg |= MPMC_STATIC_CFG_PC;
 114
 115         if (of_property_read_bool(np, "mpmc,byte-lane-low"))
 116                 cfg |= MPMC_STATIC_CFG_PB;
 117
 118         if (of_property_read_bool(np, "mpmc,extended-wait"))
 119                 cfg |= MPMC_STATIC_CFG_EW;
 120
 121         if (amba_part(adev) == 0x172 &&
 122             of_property_read_bool(np, "mpmc,buffer-enable"))
 123                 cfg |= MPMC_STATIC_CFG_B;
 124
 125         if (of_property_read_bool(np, "mpmc,write-protect"))
 126                 cfg |= MPMC_STATIC_CFG_P;
 127
 128         writel(cfg, pl172->base + MPMC_STATIC_CFG(cs));
 129         dev_dbg(&adev->dev, "mpmc static config cs%u: 0x%08x\n", cs, cfg);
 130
 131         /* MPMC static memory timing */
 132         ret = pl172_timing_prop(adev, np, "mpmc,write-enable-delay",
 133                                 MPMC_STATIC_WAIT_WEN(cs),
 134                                 MPMC_STATIC_WAIT_WEN_MAX, 1);
 135         if (ret)
 136                 goto fail;
 137
 138         ret = pl172_timing_prop(adev, np, "mpmc,output-enable-delay",
 139                                 MPMC_STATIC_WAIT_OEN(cs),
 140                                 MPMC_STATIC_WAIT_OEN_MAX, 0);
 141         if (ret)
 142                 goto fail;
 143
 144         ret = pl172_timing_prop(adev, np, "mpmc,read-access-delay",
 145                                 MPMC_STATIC_WAIT_RD(cs),
 146                                 MPMC_STATIC_WAIT_RD_MAX, 1);
 147         if (ret)
 148                 goto fail;
 149
 150         ret = pl172_timing_prop(adev, np, "mpmc,page-mode-read-delay",
 151                                 MPMC_STATIC_WAIT_PAGE(cs),
 152                                 MPMC_STATIC_WAIT_PAGE_MAX, 1);
 153         if (ret)
 154                 goto fail;
 155
 156         ret = pl172_timing_prop(adev, np, "mpmc,write-access-delay",
 157                                 MPMC_STATIC_WAIT_WR(cs),
 158                                 MPMC_STATIC_WAIT_WR_MAX, 2);
 159         if (ret)
 160                 goto fail;
 161
 162         ret = pl172_timing_prop(adev, np, "mpmc,turn-round-delay",
 163                                 MPMC_STATIC_WAIT_TURN(cs),
 164                                 MPMC_STATIC_WAIT_TURN_MAX, 1);
 165         if (ret)
 166                 goto fail;
 167
 168         return 0;
 169 fail:
 170         dev_err(&adev->dev, "failed to configure cs%u\n", cs);
 171         return ret;
 172 }
 173
 174 static int pl172_parse_cs_config(struct amba_device *adev,
 175                                  struct device_node *np)
 176 {
 177         u32 cs;
 178
 179         if (!of_property_read_u32(np, "mpmc,cs", &cs)) {
 180                 if (cs >= PL172_MAX_CS) {
 181                         dev_err(&adev->dev, "cs%u invalid\n", cs);
 182                         return -EINVAL;
 183                 }
 184
 185                 return pl172_setup_static(adev, np, cs);
 186         }
 187
 188         dev_err(&adev->dev, "cs property required\n");
 189
 190         return -EINVAL;
 191 }
 192
 193 static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
 194 static const char * const pl175_revisions[] = {"r1"};
 195 static const char * const pl176_revisions[] = {"r0"};
 196
 197 static int pl172_probe(struct amba_device *adev, const struct amba_id *id)
 198 {
 199         struct device_node *child_np, *np = adev->dev.of_node;
 200         struct device *dev = &adev->dev;
 201         static const char *rev = "?";
 202         struct pl172_data *pl172;
 203         int ret;
 204
 205         if (amba_part(adev) == 0x172) {
 206                 if (amba_rev(adev) < ARRAY_SIZE(pl172_revisions))
 207                         rev = pl172_revisions[amba_rev(adev)];
 208         } else if (amba_part(adev) == 0x175) {
 209                 if (amba_rev(adev) < ARRAY_SIZE(pl175_revisions))
 210                         rev = pl175_revisions[amba_rev(adev)];
 211         } else if (amba_part(adev) == 0x176) {
 212                 if (amba_rev(adev) < ARRAY_SIZE(pl176_revisions))
 213                         rev = pl176_revisions[amba_rev(adev)];
 214         }
 215
 216         dev_info(dev, "ARM PL%x revision %s\n", amba_part(adev), rev);
 217
 218         pl172 = devm_kzalloc(dev, sizeof(*pl172), GFP_KERNEL);
 219         if (!pl172)
 220                 return -ENOMEM;
 221
 222         pl172->clk = devm_clk_get(dev, "mpmcclk");
 223         if (IS_ERR(pl172->clk)) {
 224                 dev_err(dev, "no mpmcclk provided clock\n");
 225                 return PTR_ERR(pl172->clk);
 226         }
 227
 228         ret = clk_prepare_enable(pl172->clk);
 229         if (ret) {
 230                 dev_err(dev, "unable to mpmcclk enable clock\n");
 231                 return ret;
 232         }
 233
 234         pl172->rate = clk_get_rate(pl172->clk) / MSEC_PER_SEC;
 235         if (!pl172->rate) {
 236                 dev_err(dev, "unable to get mpmcclk clock rate\n");
 237                 ret = -EINVAL;
 238                 goto err_clk_enable;
 239         }
 240
 241         ret = amba_request_regions(adev, NULL);
 242         if (ret) {
 243                 dev_err(dev, "unable to request AMBA regions\n");
 244                 goto err_clk_enable;
 245         }
 246
 247         pl172->base = devm_ioremap(dev, adev->res.start,
 248                                    resource_size(&adev->res));
 249         if (!pl172->base) {
 250                 dev_err(dev, "ioremap failed\n");
 251                 ret = -ENOMEM;
 252                 goto err_no_ioremap;
 253         }
 254
 255         amba_set_drvdata(adev, pl172);
 256
 257         /*
 258          * Loop through each child node, which represent a chip select, and
 259          * configure parameters and timing. If successful; populate devices
 260          * under that node.
 261          */
 262         for_each_available_child_of_node(np, child_np) {
 263                 ret = pl172_parse_cs_config(adev, child_np);
 264                 if (ret)
 265                         continue;
 266
 267                 of_platform_populate(child_np, NULL, NULL, dev);
 268         }
 269
 270         return 0;
 271
 272 err_no_ioremap:
 273         amba_release_regions(adev);
 274 err_clk_enable:
 275         clk_disable_unprepare(pl172->clk);
 276         return ret;
 277 }
 278
 279 static int pl172_remove(struct amba_device *adev)
 280 {
 281         struct pl172_data *pl172 = amba_get_drvdata(adev);
 282
 283         clk_disable_unprepare(pl172->clk);
 284         amba_release_regions(adev);
 285
 286         return 0;
 287 }
 288
 289 static const struct amba_id pl172_ids[] = {
 290         /*  PrimeCell MPMC PL172, EMC found on NXP LPC18xx and LPC43xx */
 291         {
 292                 .id     = 0x07041172,
 293                 .mask   = 0x3f0fffff,
 294         },
 295         /* PrimeCell MPMC PL175, EMC found on NXP LPC32xx */
 296         {
 297                 .id     = 0x07041175,
 298                 .mask   = 0x3f0fffff,
 299         },
 300         /* PrimeCell MPMC PL176 */
 301         {
 302                 .id     = 0x89041176,
 303                 .mask   = 0xff0fffff,
 304         },
 305         { 0, 0 },
 306 };
 307 MODULE_DEVICE_TABLE(amba, pl172_ids);
 308
 309 static struct amba_driver pl172_driver = {
 310         .drv = {
 311                 .name   = "memory-pl172",
 312         },
 313         .probe          = pl172_probe,
 314         .remove         = pl172_remove,
 315         .id_table       = pl172_ids,
 316 };
 317 module_amba_driver(pl172_driver);
 318
 319 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 320 MODULE_DESCRIPTION("PL172 Memory Controller Driver");
 321 MODULE_LICENSE("GPL v2");