kernel/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 };
  27
  28 struct sunxi_sram_data {
  29         char                    *name;
  30         u8                      reg;
  31         u8                      offset;
  32         u8                      width;
  33         struct sunxi_sram_func  *func;
  34         struct list_head        list;
  35 };
  36
  37 struct sunxi_sram_desc {
  38         struct sunxi_sram_data  data;
  39         bool                    claimed;
  40 };
  41
  42 #define SUNXI_SRAM_MAP(_val, _func)                             \
  43         {                                                       \
  44                 .func = _func,                                  \
  45                 .val = _val,                                    \
  46         }
  47
  48 #define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...)         \
  49         {                                                       \
  50                 .name = _name,                                  \
  51                 .reg = _reg,                                    \
  52                 .offset = _off,                                 \
  53                 .width = _width,                                \
  54                 .func = (struct sunxi_sram_func[]){             \
  55                         __VA_ARGS__, { } },                     \
  56         }
  57
  58 static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
  59         .data   = SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
  60                                   SUNXI_SRAM_MAP(0, "cpu"),
  61                                   SUNXI_SRAM_MAP(1, "emac")),
  62 };
  63
  64 static struct sunxi_sram_desc sun4i_a10_sram_d = {
  65         .data   = SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
  66                                   SUNXI_SRAM_MAP(0, "cpu"),
  67                                   SUNXI_SRAM_MAP(1, "usb-otg")),
  68 };
  69
  70 static const struct of_device_id sunxi_sram_dt_ids[] = {
  71         {
  72                 .compatible     = "allwinner,sun4i-a10-sram-a3-a4",
  73                 .data           = &sun4i_a10_sram_a3_a4.data,
  74         },
  75         {
  76                 .compatible     = "allwinner,sun4i-a10-sram-d",
  77                 .data           = &sun4i_a10_sram_d.data,
  78         },
  79         {}
  80 };
  81
  82 static struct device *sram_dev;
  83 static LIST_HEAD(claimed_sram);
  84 static DEFINE_SPINLOCK(sram_lock);
  85 static void __iomem *base;
  86
  87 static int sunxi_sram_show(struct seq_file *s, void *data)
  88 {
  89         struct device_node *sram_node, *section_node;
  90         const struct sunxi_sram_data *sram_data;
  91         const struct of_device_id *match;
  92         struct sunxi_sram_func *func;
  93         const __be32 *sram_addr_p, *section_addr_p;
  94         u32 val;
  95
  96         seq_puts(s, "Allwinner sunXi SRAM\n");
  97         seq_puts(s, "--------------------\n\n");
  98
  99         for_each_child_of_node(sram_dev->of_node, sram_node) {
 100                 sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
 101
 102                 seq_printf(s, "sram@%08x\n",
 103                            be32_to_cpu(*sram_addr_p));
 104
 105                 for_each_child_of_node(sram_node, section_node) {
 106                         match = of_match_node(sunxi_sram_dt_ids, section_node);
 107                         if (!match)
 108                                 continue;
 109                         sram_data = match->data;
 110
 111                         section_addr_p = of_get_address(section_node, 0,
 112                                                         NULL, NULL);
 113
 114                         seq_printf(s, "\tsection@%04x\t(%s)\n",
 115                                    be32_to_cpu(*section_addr_p),
 116                                    sram_data->name);
 117
 118                         val = readl(base + sram_data->reg);
 119                         val >>= sram_data->offset;
 120                         val &= sram_data->width;
 121
 122                         for (func = sram_data->func; func->func; func++) {
 123                                 seq_printf(s, "\t\t%s%c\n", func->func,
 124                                            func->val == val ? '*' : ' ');
 125                         }
 126                 }
 127
 128                 seq_puts(s, "\n");
 129         }
 130
 131         return 0;
 132 }
 133
 134 static int sunxi_sram_open(struct inode *inode, struct file *file)
 135 {
 136         return single_open(file, sunxi_sram_show, inode->i_private);
 137 }
 138
 139 static const struct file_operations sunxi_sram_fops = {
 140         .open = sunxi_sram_open,
 141         .read = seq_read,
 142         .llseek = seq_lseek,
 143         .release = single_release,
 144 };
 145
 146 static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
 147 {
 148         return container_of(data, struct sunxi_sram_desc, data);
 149 }
 150
 151 static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
 152                                                          unsigned int *value)
 153 {
 154         const struct of_device_id *match;
 155         struct of_phandle_args args;
 156         int ret;
 157
 158         ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
 159                                                &args);
 160         if (ret)
 161                 return ERR_PTR(ret);
 162
 163         if (!of_device_is_available(args.np)) {
 164                 ret = -EBUSY;
 165                 goto err;
 166         }
 167
 168         if (value)
 169                 *value = args.args[0];
 170
 171         match = of_match_node(sunxi_sram_dt_ids, args.np);
 172         if (!match) {
 173                 ret = -EINVAL;
 174                 goto err;
 175         }
 176
 177         of_node_put(args.np);
 178         return match->data;
 179
 180 err:
 181         of_node_put(args.np);
 182         return ERR_PTR(ret);
 183 }
 184
 185 int sunxi_sram_claim(struct device *dev)
 186 {
 187         const struct sunxi_sram_data *sram_data;
 188         struct sunxi_sram_desc *sram_desc;
 189         unsigned int device;
 190         u32 val, mask;
 191
 192         if (IS_ERR(base))
 193                 return -EPROBE_DEFER;
 194
 195         if (!dev || !dev->of_node)
 196                 return -EINVAL;
 197
 198         sram_data = sunxi_sram_of_parse(dev->of_node, &device);
 199         if (IS_ERR(sram_data))
 200                 return PTR_ERR(sram_data);
 201
 202         sram_desc = to_sram_desc(sram_data);
 203
 204         spin_lock(&sram_lock);
 205
 206         if (sram_desc->claimed) {
 207                 spin_unlock(&sram_lock);
 208                 return -EBUSY;
 209         }
 210
 211         mask = GENMASK(sram_data->offset + sram_data->width, sram_data->offset);
 212         val = readl(base + sram_data->reg);
 213         val &= ~mask;
 214         writel(val | ((device << sram_data->offset) & mask),
 215                base + sram_data->reg);
 216
 217         spin_unlock(&sram_lock);
 218
 219         return 0;
 220 }
 221 EXPORT_SYMBOL(sunxi_sram_claim);
 222
 223 int sunxi_sram_release(struct device *dev)
 224 {
 225         const struct sunxi_sram_data *sram_data;
 226         struct sunxi_sram_desc *sram_desc;
 227
 228         if (!dev || !dev->of_node)
 229                 return -EINVAL;
 230
 231         sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
 232         if (IS_ERR(sram_data))
 233                 return -EINVAL;
 234
 235         sram_desc = to_sram_desc(sram_data);
 236
 237         spin_lock(&sram_lock);
 238         sram_desc->claimed = false;
 239         spin_unlock(&sram_lock);
 240
 241         return 0;
 242 }
 243 EXPORT_SYMBOL(sunxi_sram_release);
 244
 245 static int sunxi_sram_probe(struct platform_device *pdev)
 246 {
 247         struct resource *res;
 248         struct dentry *d;
 249
 250         sram_dev = &pdev->dev;
 251
 252         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 253         base = devm_ioremap_resource(&pdev->dev, res);
 254         if (IS_ERR(base))
 255                 return PTR_ERR(base);
 256
 257         of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
 258
 259         d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
 260                                 &sunxi_sram_fops);
 261         if (!d)
 262                 return -ENOMEM;
 263
 264         return 0;
 265 }
 266
 267 static const struct of_device_id sunxi_sram_dt_match[] = {
 268         { .compatible = "allwinner,sun4i-a10-sram-controller" },
 269         { },
 270 };
 271 MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
 272
 273 static struct platform_driver sunxi_sram_driver = {
 274         .driver = {
 275                 .name           = "sunxi-sram",
 276                 .of_match_table = sunxi_sram_dt_match,
 277         },
 278         .probe  = sunxi_sram_probe,
 279 };
 280 module_platform_driver(sunxi_sram_driver);
 281
 282 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
 283 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
 284 MODULE_LICENSE("GPL");