drivers/bus/imx-weim.c

   1 /*
   2  * EIM driver for Freescale's i.MX chips
   3  *
   4  * Copyright (C) 2013 Freescale Semiconductor, Inc.
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2. This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/clk.h>
  12 #include <linux/io.h>
  13 #include <linux/of_device.h>
  14 #include <linux/mfd/syscon.h>
  15 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
  16 #include <linux/regmap.h>
  17
  18 struct imx_weim_devtype {
  19         unsigned int    cs_count;
  20         unsigned int    cs_regs_count;
  21         unsigned int    cs_stride;
  22         unsigned int    wcr_offset;
  23         unsigned int    wcr_bcm;
  24         unsigned int    wcr_cont_bclk;
  25 };
  26
  27 static const struct imx_weim_devtype imx1_weim_devtype = {
  28         .cs_count       = 6,
  29         .cs_regs_count  = 2,
  30         .cs_stride      = 0x08,
  31 };
  32
  33 static const struct imx_weim_devtype imx27_weim_devtype = {
  34         .cs_count       = 6,
  35         .cs_regs_count  = 3,
  36         .cs_stride      = 0x10,
  37 };
  38
  39 static const struct imx_weim_devtype imx50_weim_devtype = {
  40         .cs_count       = 4,
  41         .cs_regs_count  = 6,
  42         .cs_stride      = 0x18,
  43         .wcr_offset     = 0x90,
  44         .wcr_bcm        = BIT(0),
  45         .wcr_cont_bclk  = BIT(3),
  46 };
  47
  48 static const struct imx_weim_devtype imx51_weim_devtype = {
  49         .cs_count       = 6,
  50         .cs_regs_count  = 6,
  51         .cs_stride      = 0x18,
  52 };
  53
  54 #define MAX_CS_REGS_COUNT       6
  55 #define MAX_CS_COUNT            6
  56 #define OF_REG_SIZE             3
  57
  58 struct cs_timing {
  59         bool is_applied;
  60         u32 regs[MAX_CS_REGS_COUNT];
  61 };
  62
  63 struct cs_timing_state {
  64         struct cs_timing cs[MAX_CS_COUNT];
  65 };
  66
  67 struct weim_priv {
  68         void __iomem *base;
  69         struct cs_timing_state timing_state;
  70 };
  71
  72 static const struct of_device_id weim_id_table[] = {
  73         /* i.MX1/21 */
  74         { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
  75         /* i.MX25/27/31/35 */
  76         { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
  77         /* i.MX50/53/6Q */
  78         { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
  79         { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
  80         /* i.MX51 */
  81         { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
  82         { }
  83 };
  84 MODULE_DEVICE_TABLE(of, weim_id_table);
  85
  86 static int imx_weim_gpr_setup(struct platform_device *pdev)
  87 {
  88         struct device_node *np = pdev->dev.of_node;
  89         struct property *prop;
  90         const __be32 *p;
  91         struct regmap *gpr;
  92         u32 gprvals[4] = {
  93                 05,     /* CS0(128M) CS1(0M)  CS2(0M)  CS3(0M)  */
  94                 033,    /* CS0(64M)  CS1(64M) CS2(0M)  CS3(0M)  */
  95                 0113,   /* CS0(64M)  CS1(32M) CS2(32M) CS3(0M)  */
  96                 01111,  /* CS0(32M)  CS1(32M) CS2(32M) CS3(32M) */
  97         };
  98         u32 gprval = 0;
  99         u32 val;
 100         int cs = 0;
 101         int i = 0;
 102
 103         gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
 104         if (IS_ERR(gpr)) {
 105                 dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
 106                 return 0;
 107         }
 108
 109         of_property_for_each_u32(np, "ranges", prop, p, val) {
 110                 if (i % 4 == 0) {
 111                         cs = val;
 112                 } else if (i % 4 == 3 && val) {
 113                         val = (val / SZ_32M) | 1;
 114                         gprval |= val << cs * 3;
 115                 }
 116                 i++;
 117         }
 118
 119         if (i == 0 || i % 4)
 120                 goto err;
 121
 122         for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
 123                 if (gprval == gprvals[i]) {
 124                         /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
 125                         regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
 126                         return 0;
 127                 }
 128         }
 129
 130 err:
 131         dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
 132         return -EINVAL;
 133 }
 134
 135 /* Parse and set the timing for this device. */
 136 static int weim_timing_setup(struct device *dev, struct device_node *np,
 137                              const struct imx_weim_devtype *devtype)
 138 {
 139         u32 cs_idx, value[MAX_CS_REGS_COUNT];
 140         int i, ret;
 141         int reg_idx, num_regs;
 142         struct cs_timing *cst;
 143         struct weim_priv *priv;
 144         struct cs_timing_state *ts;
 145         void __iomem *base;
 146
 147         if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
 148                 return -EINVAL;
 149         if (WARN_ON(devtype->cs_count > MAX_CS_COUNT))
 150                 return -EINVAL;
 151
 152         priv = dev_get_drvdata(dev);
 153         base = priv->base;
 154         ts = &priv->timing_state;
 155
 156         ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
 157                                          value, devtype->cs_regs_count);
 158         if (ret)
 159                 return ret;
 160
 161         /*
 162          * the child node's "reg" property may contain multiple address ranges,
 163          * extract the chip select for each.
 164          */
 165         num_regs = of_property_count_elems_of_size(np, "reg", OF_REG_SIZE);
 166         if (num_regs < 0)
 167                 return num_regs;
 168         if (!num_regs)
 169                 return -EINVAL;
 170         for (reg_idx = 0; reg_idx < num_regs; reg_idx++) {
 171                 /* get the CS index from this child node's "reg" property. */
 172                 ret = of_property_read_u32_index(np, "reg",
 173                                         reg_idx * OF_REG_SIZE, &cs_idx);
 174                 if (ret)
 175                         break;
 176
 177                 if (cs_idx >= devtype->cs_count)
 178                         return -EINVAL;
 179
 180                 /* prevent re-configuring a CS that's already been configured */
 181                 cst = &ts->cs[cs_idx];
 182                 if (cst->is_applied && memcmp(value, cst->regs,
 183                                         devtype->cs_regs_count * sizeof(u32))) {
 184                         dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np);
 185                         return -EINVAL;
 186                 }
 187
 188                 /* set the timing for WEIM */
 189                 for (i = 0; i < devtype->cs_regs_count; i++)
 190                         writel(value[i],
 191                                 base + cs_idx * devtype->cs_stride + i * 4);
 192                 if (!cst->is_applied) {
 193                         cst->is_applied = true;
 194                         memcpy(cst->regs, value,
 195                                 devtype->cs_regs_count * sizeof(u32));
 196                 }
 197         }
 198
 199         return 0;
 200 }
 201
 202 static int weim_parse_dt(struct platform_device *pdev)
 203 {
 204         const struct of_device_id *of_id = of_match_device(weim_id_table,
 205                                                            &pdev->dev);
 206         const struct imx_weim_devtype *devtype = of_id->data;
 207         struct device_node *child;
 208         int ret, have_child = 0;
 209         struct weim_priv *priv;
 210         void __iomem *base;
 211         u32 reg;
 212
 213         if (devtype == &imx50_weim_devtype) {
 214                 ret = imx_weim_gpr_setup(pdev);
 215                 if (ret)
 216                         return ret;
 217         }
 218
 219         priv = dev_get_drvdata(&pdev->dev);
 220         base = priv->base;
 221
 222         if (of_property_read_bool(pdev->dev.of_node, "fsl,burst-clk-enable")) {
 223                 if (devtype->wcr_bcm) {
 224                         reg = readl(base + devtype->wcr_offset);
 225                         reg |= devtype->wcr_bcm;
 226
 227                         if (of_property_read_bool(pdev->dev.of_node,
 228                                                 "fsl,continuous-burst-clk")) {
 229                                 if (devtype->wcr_cont_bclk) {
 230                                         reg |= devtype->wcr_cont_bclk;
 231                                 } else {
 232                                         dev_err(&pdev->dev,
 233                                                 "continuous burst clk not supported.\n");
 234                                         return -EINVAL;
 235                                 }
 236                         }
 237
 238                         writel(reg, base + devtype->wcr_offset);
 239                 } else {
 240                         dev_err(&pdev->dev, "burst clk mode not supported.\n");
 241                         return -EINVAL;
 242                 }
 243         }
 244
 245         for_each_available_child_of_node(pdev->dev.of_node, child) {
 246                 ret = weim_timing_setup(&pdev->dev, child, devtype);
 247                 if (ret)
 248                         dev_warn(&pdev->dev, "%pOF set timing failed.\n",
 249                                 child);
 250                 else
 251                         have_child = 1;
 252         }
 253
 254         if (have_child)
 255                 ret = of_platform_default_populate(pdev->dev.of_node,
 256                                                    NULL, &pdev->dev);
 257         if (ret)
 258                 dev_err(&pdev->dev, "%pOF fail to create devices.\n",
 259                         pdev->dev.of_node);
 260         return ret;
 261 }
 262
 263 static int weim_probe(struct platform_device *pdev)
 264 {
 265         struct weim_priv *priv;
 266         struct resource *res;
 267         struct clk *clk;
 268         void __iomem *base;
 269         int ret;
 270
 271         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 272         if (!priv)
 273                 return -ENOMEM;
 274
 275         /* get the resource */
 276         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 277         base = devm_ioremap_resource(&pdev->dev, res);
 278         if (IS_ERR(base))
 279                 return PTR_ERR(base);
 280
 281         priv->base = base;
 282         dev_set_drvdata(&pdev->dev, priv);
 283
 284         /* get the clock */
 285         clk = devm_clk_get(&pdev->dev, NULL);
 286         if (IS_ERR(clk))
 287                 return PTR_ERR(clk);
 288
 289         ret = clk_prepare_enable(clk);
 290         if (ret)
 291                 return ret;
 292
 293         /* parse the device node */
 294         ret = weim_parse_dt(pdev);
 295         if (ret)
 296                 clk_disable_unprepare(clk);
 297         else
 298                 dev_info(&pdev->dev, "Driver registered.\n");
 299
 300         return ret;
 301 }
 302
 303 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
 304 static int of_weim_notify(struct notifier_block *nb, unsigned long action,
 305                           void *arg)
 306 {
 307         const struct imx_weim_devtype *devtype;
 308         struct of_reconfig_data *rd = arg;
 309         const struct of_device_id *of_id;
 310         struct platform_device *pdev;
 311         int ret = NOTIFY_OK;
 312
 313         switch (of_reconfig_get_state_change(action, rd)) {
 314         case OF_RECONFIG_CHANGE_ADD:
 315                 of_id = of_match_node(weim_id_table, rd->dn->parent);
 316                 if (!of_id)
 317                         return NOTIFY_OK; /* not for us */
 318
 319                 devtype = of_id->data;
 320
 321                 pdev = of_find_device_by_node(rd->dn->parent);
 322                 if (!pdev) {
 323                         pr_err("%s: could not find platform device for '%pOF'\n",
 324                                 __func__, rd->dn->parent);
 325
 326                         return notifier_from_errno(-EINVAL);
 327                 }
 328
 329                 if (weim_timing_setup(&pdev->dev, rd->dn, devtype))
 330                         dev_warn(&pdev->dev,
 331                                  "Failed to setup timing for '%pOF'\n", rd->dn);
 332
 333                 if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
 334                         if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
 335                                 dev_err(&pdev->dev,
 336                                         "Failed to create child device '%pOF'\n",
 337                                         rd->dn);
 338                                 ret = notifier_from_errno(-EINVAL);
 339                         }
 340                 }
 341
 342                 platform_device_put(pdev);
 343
 344                 break;
 345         case OF_RECONFIG_CHANGE_REMOVE:
 346                 if (!of_node_check_flag(rd->dn, OF_POPULATED))
 347                         return NOTIFY_OK; /* device already destroyed */
 348
 349                 of_id = of_match_node(weim_id_table, rd->dn->parent);
 350                 if (!of_id)
 351                         return NOTIFY_OK; /* not for us */
 352
 353                 pdev = of_find_device_by_node(rd->dn);
 354                 if (!pdev) {
 355                         pr_err("Could not find platform device for '%pOF'\n",
 356                                 rd->dn);
 357
 358                         ret = notifier_from_errno(-EINVAL);
 359                 } else {
 360                         of_platform_device_destroy(&pdev->dev, NULL);
 361                         platform_device_put(pdev);
 362                 }
 363
 364                 break;
 365         default:
 366                 break;
 367         }
 368
 369         return ret;
 370 }
 371
 372 static struct notifier_block weim_of_notifier = {
 373         .notifier_call = of_weim_notify,
 374 };
 375 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
 376
 377 static struct platform_driver weim_driver = {
 378         .driver = {
 379                 .name           = "imx-weim",
 380                 .of_match_table = weim_id_table,
 381         },
 382         .probe = weim_probe,
 383 };
 384
 385 static int __init weim_init(void)
 386 {
 387 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
 388         WARN_ON(of_reconfig_notifier_register(&weim_of_notifier));
 389 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
 390
 391         return platform_driver_register(&weim_driver);
 392 }
 393 module_init(weim_init);
 394
 395 static void __exit weim_exit(void)
 396 {
 397 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
 398         of_reconfig_notifier_unregister(&weim_of_notifier);
 399 #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
 400
 401         return platform_driver_unregister(&weim_driver);
 402
 403 }
 404 module_exit(weim_exit);
 405
 406 MODULE_AUTHOR("Freescale Semiconductor Inc.");
 407 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
 408 MODULE_LICENSE("GPL");