linux/drivers/memory/pl172.c
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   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
  53struct pl172_data {
  54        void __iomem *base;
  55        unsigned long rate;
  56        struct clk *clk;
  57};
  58
  59static 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
  85static 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;
 169fail:
 170        dev_err(&adev->dev, "failed to configure cs%u\n", cs);
 171        return ret;
 172}
 173
 174static 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
 193static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
 194static const char * const pl175_revisions[] = {"r1"};
 195static const char * const pl176_revisions[] = {"r0"};
 196
 197static 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
 272err_no_ioremap:
 273        amba_release_regions(adev);
 274err_clk_enable:
 275        clk_disable_unprepare(pl172->clk);
 276        return ret;
 277}
 278
 279static 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
 289static 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};
 307MODULE_DEVICE_TABLE(amba, pl172_ids);
 308
 309static 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};
 317module_amba_driver(pl172_driver);
 318
 319MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 320MODULE_DESCRIPTION("PL172 Memory Controller Driver");
 321MODULE_LICENSE("GPL v2");
 322