drivers/remoteproc/meson_mx_ao_arc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2020 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
   4  */
   5
   6 #include <linux/bitfield.h>
   7 #include <linux/bitops.h>
   8 #include <linux/clk.h>
   9 #include <linux/delay.h>
  10 #include <linux/genalloc.h>
  11 #include <linux/io.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/property.h>
  16 #include <linux/regmap.h>
  17 #include <linux/remoteproc.h>
  18 #include <linux/reset.h>
  19 #include <linux/sizes.h>
  20
  21 #include "remoteproc_internal.h"
  22
  23 #define AO_REMAP_REG0                                           0x0
  24 #define AO_REMAP_REG0_REMAP_AHB_SRAM_BITS_17_14_FOR_ARM_CPU     GENMASK(3, 0)
  25
  26 #define AO_REMAP_REG1                                           0x4
  27 #define AO_REMAP_REG1_MOVE_AHB_SRAM_TO_0X0_INSTEAD_OF_DDR       BIT(4)
  28 #define AO_REMAP_REG1_REMAP_AHB_SRAM_BITS_17_14_FOR_MEDIA_CPU   GENMASK(3, 0)
  29
  30 #define AO_CPU_CNTL                                             0x0
  31 #define AO_CPU_CNTL_AHB_SRAM_BITS_31_20                         GENMASK(28, 16)
  32 #define AO_CPU_CNTL_HALT                                        BIT(9)
  33 #define AO_CPU_CNTL_UNKNONWN                                    BIT(8)
  34 #define AO_CPU_CNTL_RUN                                         BIT(0)
  35
  36 #define AO_CPU_STAT                                             0x4
  37
  38 #define AO_SECURE_REG0                                          0x0
  39 #define AO_SECURE_REG0_AHB_SRAM_BITS_19_12                      GENMASK(15, 8)
  40
  41 /* Only bits [31:20] and [17:14] are usable, all other bits must be zero */
  42 #define MESON_AO_RPROC_SRAM_USABLE_BITS                         0xfff3c000ULL
  43
  44 #define MESON_AO_RPROC_MEMORY_OFFSET                            0x10000000
  45
  46 struct meson_mx_ao_arc_rproc_priv {
  47         void __iomem            *remap_base;
  48         void __iomem            *cpu_base;
  49         unsigned long           sram_va;
  50         phys_addr_t             sram_pa;
  51         size_t                  sram_size;
  52         struct gen_pool         *sram_pool;
  53         struct reset_control    *arc_reset;
  54         struct clk              *arc_pclk;
  55         struct regmap           *secbus2_regmap;
  56 };
  57
  58 static int meson_mx_ao_arc_rproc_start(struct rproc *rproc)
  59 {
  60         struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
  61         phys_addr_t translated_sram_addr;
  62         u32 tmp;
  63         int ret;
  64
  65         ret = clk_prepare_enable(priv->arc_pclk);
  66         if (ret)
  67                 return ret;
  68
  69         tmp = FIELD_PREP(AO_REMAP_REG0_REMAP_AHB_SRAM_BITS_17_14_FOR_ARM_CPU,
  70                          priv->sram_pa >> 14);
  71         writel(tmp, priv->remap_base + AO_REMAP_REG0);
  72
  73         /*
  74          * The SRAM content as seen by the ARC core always starts at 0x0
  75          * regardless of the value given here (this was discovered by trial and
  76          * error). For SoCs older than Meson6 we probably have to set
  77          * AO_REMAP_REG1_MOVE_AHB_SRAM_TO_0X0_INSTEAD_OF_DDR to achieve the
  78          * same. (At least) For Meson8 and newer that bit must not be set.
  79          */
  80         writel(0x0, priv->remap_base + AO_REMAP_REG1);
  81
  82         regmap_update_bits(priv->secbus2_regmap, AO_SECURE_REG0,
  83                            AO_SECURE_REG0_AHB_SRAM_BITS_19_12,
  84                            FIELD_PREP(AO_SECURE_REG0_AHB_SRAM_BITS_19_12,
  85                                       priv->sram_pa >> 12));
  86
  87         ret = reset_control_reset(priv->arc_reset);
  88         if (ret) {
  89                 clk_disable_unprepare(priv->arc_pclk);
  90                 return ret;
  91         }
  92
  93         usleep_range(10, 100);
  94
  95         /*
  96          * Convert from 0xd9000000 to 0xc9000000 as the vendor driver does.
  97          * This only seems to be relevant for the AO_CPU_CNTL register. It is
  98          * unknown why this is needed.
  99          */
 100         translated_sram_addr = priv->sram_pa - MESON_AO_RPROC_MEMORY_OFFSET;
 101
 102         tmp = FIELD_PREP(AO_CPU_CNTL_AHB_SRAM_BITS_31_20,
 103                          translated_sram_addr >> 20);
 104         tmp |= AO_CPU_CNTL_UNKNONWN | AO_CPU_CNTL_RUN;
 105         writel(tmp, priv->cpu_base + AO_CPU_CNTL);
 106
 107         usleep_range(20, 200);
 108
 109         return 0;
 110 }
 111
 112 static int meson_mx_ao_arc_rproc_stop(struct rproc *rproc)
 113 {
 114         struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
 115
 116         writel(AO_CPU_CNTL_HALT, priv->cpu_base + AO_CPU_CNTL);
 117
 118         clk_disable_unprepare(priv->arc_pclk);
 119
 120         return 0;
 121 }
 122
 123 static void *meson_mx_ao_arc_rproc_da_to_va(struct rproc *rproc, u64 da,
 124                                             size_t len, bool *is_iomem)
 125 {
 126         struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
 127
 128         /* The memory from the ARC core's perspective always starts at 0x0. */
 129         if ((da + len) > priv->sram_size)
 130                 return NULL;
 131
 132         return (void *)priv->sram_va + da;
 133 }
 134
 135 static struct rproc_ops meson_mx_ao_arc_rproc_ops = {
 136         .start          = meson_mx_ao_arc_rproc_start,
 137         .stop           = meson_mx_ao_arc_rproc_stop,
 138         .da_to_va       = meson_mx_ao_arc_rproc_da_to_va,
 139         .get_boot_addr  = rproc_elf_get_boot_addr,
 140         .load           = rproc_elf_load_segments,
 141         .sanity_check   = rproc_elf_sanity_check,
 142 };
 143
 144 static int meson_mx_ao_arc_rproc_probe(struct platform_device *pdev)
 145 {
 146         struct meson_mx_ao_arc_rproc_priv *priv;
 147         struct device *dev = &pdev->dev;
 148         const char *fw_name = NULL;
 149         struct rproc *rproc;
 150         int ret;
 151
 152         device_property_read_string(dev, "firmware-name", &fw_name);
 153
 154         rproc = devm_rproc_alloc(dev, "meson-mx-ao-arc",
 155                                  &meson_mx_ao_arc_rproc_ops, fw_name,
 156                                  sizeof(*priv));
 157         if (!rproc)
 158                 return -ENOMEM;
 159
 160         rproc->has_iommu = false;
 161         priv = rproc->priv;
 162
 163         priv->sram_pool = of_gen_pool_get(dev->of_node, "sram", 0);
 164         if (!priv->sram_pool) {
 165                 dev_err(dev, "Could not get SRAM pool\n");
 166                 return -ENODEV;
 167         }
 168
 169         priv->sram_size = gen_pool_avail(priv->sram_pool);
 170
 171         priv->sram_va = gen_pool_alloc(priv->sram_pool, priv->sram_size);
 172         if (!priv->sram_va) {
 173                 dev_err(dev, "Could not alloc memory in SRAM pool\n");
 174                 return -ENOMEM;
 175         }
 176
 177         priv->sram_pa = gen_pool_virt_to_phys(priv->sram_pool, priv->sram_va);
 178         if (priv->sram_pa & ~MESON_AO_RPROC_SRAM_USABLE_BITS) {
 179                 dev_err(dev, "SRAM address contains unusable bits\n");
 180                 ret = -EINVAL;
 181                 goto err_free_genpool;
 182         }
 183
 184         priv->secbus2_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
 185                                                                "amlogic,secbus2");
 186         if (IS_ERR(priv->secbus2_regmap)) {
 187                 dev_err(dev, "Failed to find SECBUS2 regmap\n");
 188                 ret = PTR_ERR(priv->secbus2_regmap);
 189                 goto err_free_genpool;
 190         }
 191
 192         priv->remap_base = devm_platform_ioremap_resource_byname(pdev, "remap");
 193         if (IS_ERR(priv->remap_base)) {
 194                 ret = PTR_ERR(priv->remap_base);
 195                 goto err_free_genpool;
 196         }
 197
 198         priv->cpu_base = devm_platform_ioremap_resource_byname(pdev, "cpu");
 199         if (IS_ERR(priv->cpu_base)) {
 200                 ret = PTR_ERR(priv->cpu_base);
 201                 goto err_free_genpool;
 202         }
 203
 204         priv->arc_reset = devm_reset_control_get_exclusive(dev, NULL);
 205         if (IS_ERR(priv->arc_reset)) {
 206                 dev_err(dev, "Failed to get ARC reset\n");
 207                 ret = PTR_ERR(priv->arc_reset);
 208                 goto err_free_genpool;
 209         }
 210
 211         priv->arc_pclk = devm_clk_get(dev, NULL);
 212         if (IS_ERR(priv->arc_pclk)) {
 213                 dev_err(dev, "Failed to get the ARC PCLK\n");
 214                 ret = PTR_ERR(priv->arc_pclk);
 215                 goto err_free_genpool;
 216         }
 217
 218         platform_set_drvdata(pdev, rproc);
 219
 220         ret = rproc_add(rproc);
 221         if (ret)
 222                 goto err_free_genpool;
 223
 224         return 0;
 225
 226 err_free_genpool:
 227         gen_pool_free(priv->sram_pool, priv->sram_va, priv->sram_size);
 228         return ret;
 229 }
 230
 231 static void meson_mx_ao_arc_rproc_remove(struct platform_device *pdev)
 232 {
 233         struct rproc *rproc = platform_get_drvdata(pdev);
 234         struct meson_mx_ao_arc_rproc_priv *priv = rproc->priv;
 235
 236         rproc_del(rproc);
 237         gen_pool_free(priv->sram_pool, priv->sram_va, priv->sram_size);
 238 }
 239
 240 static const struct of_device_id meson_mx_ao_arc_rproc_match[] = {
 241         { .compatible = "amlogic,meson8-ao-arc" },
 242         { .compatible = "amlogic,meson8b-ao-arc" },
 243         { /* sentinel */ }
 244 };
 245 MODULE_DEVICE_TABLE(of, meson_mx_ao_arc_rproc_match);
 246
 247 static struct platform_driver meson_mx_ao_arc_rproc_driver = {
 248         .probe = meson_mx_ao_arc_rproc_probe,
 249         .remove = meson_mx_ao_arc_rproc_remove,
 250         .driver = {
 251                 .name = "meson-mx-ao-arc-rproc",
 252                 .of_match_table = meson_mx_ao_arc_rproc_match,
 253         },
 254 };
 255 module_platform_driver(meson_mx_ao_arc_rproc_driver);
 256
 257 MODULE_DESCRIPTION("Amlogic Meson6/8/8b/8m2 AO ARC remote processor driver");
 258 MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
 259 MODULE_LICENSE("GPL v2");