drivers/soc/sunxi/sunxi_sram.c

   1 /*
   2  * Allwinner SoCs SRAM Controller Driver
   3  *
   4  * Copyright (C) 2015 Maxime Ripard
   5  *
   6  * Author: Maxime Ripard <maxime.ripard@free-electrons.com>
   7  *
   8  * This file is licensed under the terms of the GNU General Public
   9  * License version 2.  This program is licensed "as is" without any
  10  * warranty of any kind, whether express or implied.
  11  */
  12
  13 #include <linux/debugfs.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/of_device.h>
  19 #include <linux/platform_device.h>
  20
  21 #include <linux/soc/sunxi/sunxi_sram.h>
  22
  23 struct sunxi_sram_func {
  24         char    *func;
  25         u8      val;
  26         u32     reg_val;
  27 };
  28
  29 struct sunxi_sram_data {
  30         char                    *name;
  31         u8                      reg;
  32         u8                      offset;
  33         u8                      width;
  34         struct sunxi_sram_func  *func;
  35         struct list_head        list;
  36 };
  37
  38 struct sunxi_sram_desc {
  39         struct sunxi_sram_data  data;
  40         bool                    claimed;
  41 };
  42
  43 #define SUNXI_SRAM_MAP(_reg_val, _val, _func)                   \
  44         {                                                       \
  45                 .func = _func,                                  \
  46                 .val = _val,                                    \
  47                 .reg_val = _reg_val,                            \
  48         }
  49
  50 #define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...)         \
  51         {                                                       \
  52                 .name = _name,                                  \
  53                 .reg = _reg,                                    \
  54                 .offset = _off,                                 \
  55                 .width = _width,                                \
  56                 .func = (struct sunxi_sram_func[]){             \
  57                         __VA_ARGS__, { } },                     \
  58         }
  59
  60 static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
  61         .data   = SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
  62                                   SUNXI_SRAM_MAP(0, 0, "cpu"),
  63                                   SUNXI_SRAM_MAP(1, 1, "emac")),
  64 };
  65
  66 static struct sunxi_sram_desc sun4i_a10_sram_d = {
  67         .data   = SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
  68                                   SUNXI_SRAM_MAP(0, 0, "cpu"),
  69                                   SUNXI_SRAM_MAP(1, 1, "usb-otg")),
  70 };
  71
  72 static struct sunxi_sram_desc sun50i_a64_sram_c = {
  73         .data   = SUNXI_SRAM_DATA("C", 0x4, 24, 1,
  74                                   SUNXI_SRAM_MAP(0, 1, "cpu"),
  75                                   SUNXI_SRAM_MAP(1, 0, "de2")),
  76 };
  77
  78 static const struct of_device_id sunxi_sram_dt_ids[] = {
  79         {
  80                 .compatible     = "allwinner,sun4i-a10-sram-a3-a4",
  81                 .data           = &sun4i_a10_sram_a3_a4.data,
  82         },
  83         {
  84                 .compatible     = "allwinner,sun4i-a10-sram-d",
  85                 .data           = &sun4i_a10_sram_d.data,
  86         },
  87         {
  88                 .compatible     = "allwinner,sun50i-a64-sram-c",
  89                 .data           = &sun50i_a64_sram_c.data,
  90         },
  91         {}
  92 };
  93
  94 static struct device *sram_dev;
  95 static LIST_HEAD(claimed_sram);
  96 static DEFINE_SPINLOCK(sram_lock);
  97 static void __iomem *base;
  98
  99 static int sunxi_sram_show(struct seq_file *s, void *data)
 100 {
 101         struct device_node *sram_node, *section_node;
 102         const struct sunxi_sram_data *sram_data;
 103         const struct of_device_id *match;
 104         struct sunxi_sram_func *func;
 105         const __be32 *sram_addr_p, *section_addr_p;
 106         u32 val;
 107
 108         seq_puts(s, "Allwinner sunXi SRAM\n");
 109         seq_puts(s, "--------------------\n\n");
 110
 111         for_each_child_of_node(sram_dev->of_node, sram_node) {
 112                 sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
 113
 114                 seq_printf(s, "sram@%08x\n",
 115                            be32_to_cpu(*sram_addr_p));
 116
 117                 for_each_child_of_node(sram_node, section_node) {
 118                         match = of_match_node(sunxi_sram_dt_ids, section_node);
 119                         if (!match)
 120                                 continue;
 121                         sram_data = match->data;
 122
 123                         section_addr_p = of_get_address(section_node, 0,
 124                                                         NULL, NULL);
 125
 126                         seq_printf(s, "\tsection@%04x\t(%s)\n",
 127                                    be32_to_cpu(*section_addr_p),
 128                                    sram_data->name);
 129
 130                         val = readl(base + sram_data->reg);
 131                         val >>= sram_data->offset;
 132                         val &= GENMASK(sram_data->width - 1, 0);
 133
 134                         for (func = sram_data->func; func->func; func++) {
 135                                 seq_printf(s, "\t\t%s%c\n", func->func,
 136                                            func->reg_val == val ?
 137                                            '*' : ' ');
 138                         }
 139                 }
 140
 141                 seq_puts(s, "\n");
 142         }
 143
 144         return 0;
 145 }
 146
 147 static int sunxi_sram_open(struct inode *inode, struct file *file)
 148 {
 149         return single_open(file, sunxi_sram_show, inode->i_private);
 150 }
 151
 152 static const struct file_operations sunxi_sram_fops = {
 153         .open = sunxi_sram_open,
 154         .read = seq_read,
 155         .llseek = seq_lseek,
 156         .release = single_release,
 157 };
 158
 159 static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
 160 {
 161         return container_of(data, struct sunxi_sram_desc, data);
 162 }
 163
 164 static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
 165                                                          unsigned int *reg_value)
 166 {
 167         const struct of_device_id *match;
 168         const struct sunxi_sram_data *data;
 169         struct sunxi_sram_func *func;
 170         struct of_phandle_args args;
 171         u8 val;
 172         int ret;
 173
 174         ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
 175                                                &args);
 176         if (ret)
 177                 return ERR_PTR(ret);
 178
 179         if (!of_device_is_available(args.np)) {
 180                 ret = -EBUSY;
 181                 goto err;
 182         }
 183
 184         val = args.args[0];
 185
 186         match = of_match_node(sunxi_sram_dt_ids, args.np);
 187         if (!match) {
 188                 ret = -EINVAL;
 189                 goto err;
 190         }
 191
 192         data = match->data;
 193         if (!data) {
 194                 ret = -EINVAL;
 195                 goto err;
 196         };
 197
 198         for (func = data->func; func->func; func++) {
 199                 if (val == func->val) {
 200                         if (reg_value)
 201                                 *reg_value = func->reg_val;
 202
 203                         break;
 204                 }
 205         }
 206
 207         if (!func->func) {
 208                 ret = -EINVAL;
 209                 goto err;
 210         }
 211
 212         of_node_put(args.np);
 213         return match->data;
 214
 215 err:
 216         of_node_put(args.np);
 217         return ERR_PTR(ret);
 218 }
 219
 220 int sunxi_sram_claim(struct device *dev)
 221 {
 222         const struct sunxi_sram_data *sram_data;
 223         struct sunxi_sram_desc *sram_desc;
 224         unsigned int device;
 225         u32 val, mask;
 226
 227         if (IS_ERR(base))
 228                 return PTR_ERR(base);
 229
 230         if (!base)
 231                 return -EPROBE_DEFER;
 232
 233         if (!dev || !dev->of_node)
 234                 return -EINVAL;
 235
 236         sram_data = sunxi_sram_of_parse(dev->of_node, &device);
 237         if (IS_ERR(sram_data))
 238                 return PTR_ERR(sram_data);
 239
 240         sram_desc = to_sram_desc(sram_data);
 241
 242         spin_lock(&sram_lock);
 243
 244         if (sram_desc->claimed) {
 245                 spin_unlock(&sram_lock);
 246                 return -EBUSY;
 247         }
 248
 249         mask = GENMASK(sram_data->offset + sram_data->width - 1,
 250                        sram_data->offset);
 251         val = readl(base + sram_data->reg);
 252         val &= ~mask;
 253         writel(val | ((device << sram_data->offset) & mask),
 254                base + sram_data->reg);
 255
 256         spin_unlock(&sram_lock);
 257
 258         return 0;
 259 }
 260 EXPORT_SYMBOL(sunxi_sram_claim);
 261
 262 int sunxi_sram_release(struct device *dev)
 263 {
 264         const struct sunxi_sram_data *sram_data;
 265         struct sunxi_sram_desc *sram_desc;
 266
 267         if (!dev || !dev->of_node)
 268                 return -EINVAL;
 269
 270         sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
 271         if (IS_ERR(sram_data))
 272                 return -EINVAL;
 273
 274         sram_desc = to_sram_desc(sram_data);
 275
 276         spin_lock(&sram_lock);
 277         sram_desc->claimed = false;
 278         spin_unlock(&sram_lock);
 279
 280         return 0;
 281 }
 282 EXPORT_SYMBOL(sunxi_sram_release);
 283
 284 static int sunxi_sram_probe(struct platform_device *pdev)
 285 {
 286         struct resource *res;
 287         struct dentry *d;
 288
 289         sram_dev = &pdev->dev;
 290
 291         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 292         base = devm_ioremap_resource(&pdev->dev, res);
 293         if (IS_ERR(base))
 294                 return PTR_ERR(base);
 295
 296         of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
 297
 298         d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
 299                                 &sunxi_sram_fops);
 300         if (!d)
 301                 return -ENOMEM;
 302
 303         return 0;
 304 }
 305
 306 static const struct of_device_id sunxi_sram_dt_match[] = {
 307         { .compatible = "allwinner,sun4i-a10-sram-controller" },
 308         { .compatible = "allwinner,sun50i-a64-sram-controller" },
 309         { },
 310 };
 311 MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
 312
 313 static struct platform_driver sunxi_sram_driver = {
 314         .driver = {
 315                 .name           = "sunxi-sram",
 316                 .of_match_table = sunxi_sram_dt_match,
 317         },
 318         .probe  = sunxi_sram_probe,
 319 };
 320 module_platform_driver(sunxi_sram_driver);
 321
 322 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 323 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
 324 MODULE_LICENSE("GPL");