drivers/pinctrl/berlin/berlin.c

   1 /*
   2  * Marvell Berlin SoC pinctrl core driver
   3  *
   4  * Copyright (C) 2014 Marvell Technology Group Ltd.
   5  *
   6  * Antoine Ténart <antoine.tenart@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/io.h>
  14 #include <linux/mfd/syscon.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/pinctrl/pinctrl.h>
  20 #include <linux/pinctrl/pinmux.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/regmap.h>
  23 #include <linux/slab.h>
  24
  25 #include "../core.h"
  26 #include "../pinctrl-utils.h"
  27 #include "berlin.h"
  28
  29 struct berlin_pinctrl {
  30         struct regmap *regmap;
  31         struct device *dev;
  32         const struct berlin_pinctrl_desc *desc;
  33         struct berlin_pinctrl_function *functions;
  34         unsigned nfunctions;
  35         struct pinctrl_dev *pctrl_dev;
  36 };
  37
  38 static int berlin_pinctrl_get_group_count(struct pinctrl_dev *pctrl_dev)
  39 {
  40         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  41
  42         return pctrl->desc->ngroups;
  43 }
  44
  45 static const char *berlin_pinctrl_get_group_name(struct pinctrl_dev *pctrl_dev,
  46                                                  unsigned group)
  47 {
  48         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  49
  50         return pctrl->desc->groups[group].name;
  51 }
  52
  53 static int berlin_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrl_dev,
  54                                          struct device_node *node,
  55                                          struct pinctrl_map **map,
  56                                          unsigned *num_maps)
  57 {
  58         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  59         struct property *prop;
  60         const char *function_name, *group_name;
  61         unsigned reserved_maps = 0;
  62         int ret, ngroups;
  63
  64         *map = NULL;
  65         *num_maps = 0;
  66
  67         ret = of_property_read_string(node, "function", &function_name);
  68         if (ret) {
  69                 dev_err(pctrl->dev,
  70                         "missing function property in node %s\n",
  71                         node->name);
  72                 return -EINVAL;
  73         }
  74
  75         ngroups = of_property_count_strings(node, "groups");
  76         if (ngroups < 0) {
  77                 dev_err(pctrl->dev,
  78                         "missing groups property in node %s\n",
  79                         node->name);
  80                 return -EINVAL;
  81         }
  82
  83         ret = pinctrl_utils_reserve_map(pctrl_dev, map, &reserved_maps,
  84                                         num_maps, ngroups);
  85         if (ret) {
  86                 dev_err(pctrl->dev, "can't reserve map: %d\n", ret);
  87                 return ret;
  88         }
  89
  90         of_property_for_each_string(node, "groups", prop, group_name) {
  91                 ret = pinctrl_utils_add_map_mux(pctrl_dev, map, &reserved_maps,
  92                                                 num_maps, group_name,
  93                                                 function_name);
  94                 if (ret) {
  95                         dev_err(pctrl->dev, "can't add map: %d\n", ret);
  96                         return ret;
  97                 }
  98         }
  99
 100         return 0;
 101 }
 102
 103 static const struct pinctrl_ops berlin_pinctrl_ops = {
 104         .get_groups_count       = &berlin_pinctrl_get_group_count,
 105         .get_group_name         = &berlin_pinctrl_get_group_name,
 106         .dt_node_to_map         = &berlin_pinctrl_dt_node_to_map,
 107         .dt_free_map            = &pinctrl_utils_dt_free_map,
 108 };
 109
 110 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
 111 {
 112         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 113
 114         return pctrl->nfunctions;
 115 }
 116
 117 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
 118                                                    unsigned function)
 119 {
 120         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 121
 122         return pctrl->functions[function].name;
 123 }
 124
 125 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
 126                                              unsigned function,
 127                                              const char * const **groups,
 128                                              unsigned * const num_groups)
 129 {
 130         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 131
 132         *groups = pctrl->functions[function].groups;
 133         *num_groups = pctrl->functions[function].ngroups;
 134
 135         return 0;
 136 }
 137
 138 static struct berlin_desc_function *
 139 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
 140                                      const struct berlin_desc_group *group,
 141                                      const char *fname)
 142 {
 143         struct berlin_desc_function *function = group->functions;
 144
 145         while (function->name) {
 146                 if (!strcmp(function->name, fname))
 147                         return function;
 148
 149                 function++;
 150         }
 151
 152         return NULL;
 153 }
 154
 155 static int berlin_pinmux_set(struct pinctrl_dev *pctrl_dev,
 156                              unsigned function,
 157                              unsigned group)
 158 {
 159         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 160         const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
 161         struct berlin_pinctrl_function *func = pctrl->functions + function;
 162         struct berlin_desc_function *function_desc =
 163                 berlin_pinctrl_find_function_by_name(pctrl, group_desc,
 164                                                      func->name);
 165         u32 mask, val;
 166
 167         if (!function_desc)
 168                 return -EINVAL;
 169
 170         mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
 171                        group_desc->lsb);
 172         val = function_desc->muxval << group_desc->lsb;
 173         regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
 174
 175         return 0;
 176 }
 177
 178 static const struct pinmux_ops berlin_pinmux_ops = {
 179         .get_functions_count    = &berlin_pinmux_get_functions_count,
 180         .get_function_name      = &berlin_pinmux_get_function_name,
 181         .get_function_groups    = &berlin_pinmux_get_function_groups,
 182         .set_mux                = &berlin_pinmux_set,
 183 };
 184
 185 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
 186                                        const char *name)
 187 {
 188         struct berlin_pinctrl_function *function = pctrl->functions;
 189
 190         while (function->name) {
 191                 if (!strcmp(function->name, name)) {
 192                         function->ngroups++;
 193                         return -EEXIST;
 194                 }
 195                 function++;
 196         }
 197
 198         function->name = name;
 199         function->ngroups = 1;
 200
 201         pctrl->nfunctions++;
 202
 203         return 0;
 204 }
 205
 206 static int berlin_pinctrl_build_state(struct platform_device *pdev)
 207 {
 208         struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
 209         struct berlin_desc_group const *desc_group;
 210         struct berlin_desc_function const *desc_function;
 211         int i, max_functions = 0;
 212
 213         pctrl->nfunctions = 0;
 214
 215         for (i = 0; i < pctrl->desc->ngroups; i++) {
 216                 desc_group = pctrl->desc->groups + i;
 217                 /* compute the maxiumum number of functions a group can have */
 218                 max_functions += 1 << (desc_group->bit_width + 1);
 219         }
 220
 221         /* we will reallocate later */
 222         pctrl->functions = devm_kzalloc(&pdev->dev,
 223                                         max_functions * sizeof(*pctrl->functions),
 224                                         GFP_KERNEL);
 225         if (!pctrl->functions)
 226                 return -ENOMEM;
 227
 228         /* register all functions */
 229         for (i = 0; i < pctrl->desc->ngroups; i++) {
 230                 desc_group = pctrl->desc->groups + i;
 231                 desc_function = desc_group->functions;
 232
 233                 while (desc_function->name) {
 234                         berlin_pinctrl_add_function(pctrl, desc_function->name);
 235                         desc_function++;
 236                 }
 237         }
 238
 239         pctrl->functions = krealloc(pctrl->functions,
 240                                     pctrl->nfunctions * sizeof(*pctrl->functions),
 241                                     GFP_KERNEL);
 242
 243         /* map functions to theirs groups */
 244         for (i = 0; i < pctrl->desc->ngroups; i++) {
 245                 desc_group = pctrl->desc->groups + i;
 246                 desc_function = desc_group->functions;
 247
 248                 while (desc_function->name) {
 249                         struct berlin_pinctrl_function
 250                                 *function = pctrl->functions;
 251                         const char **groups;
 252                         bool found = false;
 253
 254                         while (function->name) {
 255                                 if (!strcmp(desc_function->name, function->name)) {
 256                                         found = true;
 257                                         break;
 258                                 }
 259                                 function++;
 260                         }
 261
 262                         if (!found)
 263                                 return -EINVAL;
 264
 265                         if (!function->groups) {
 266                                 function->groups =
 267                                         devm_kzalloc(&pdev->dev,
 268                                                      function->ngroups * sizeof(char *),
 269                                                      GFP_KERNEL);
 270
 271                                 if (!function->groups)
 272                                         return -ENOMEM;
 273                         }
 274
 275                         groups = function->groups;
 276                         while (*groups)
 277                                 groups++;
 278
 279                         *groups = desc_group->name;
 280
 281                         desc_function++;
 282                 }
 283         }
 284
 285         return 0;
 286 }
 287
 288 static struct pinctrl_desc berlin_pctrl_desc = {
 289         .name           = "berlin-pinctrl",
 290         .pctlops        = &berlin_pinctrl_ops,
 291         .pmxops         = &berlin_pinmux_ops,
 292         .owner          = THIS_MODULE,
 293 };
 294
 295 int berlin_pinctrl_probe_regmap(struct platform_device *pdev,
 296                                 const struct berlin_pinctrl_desc *desc,
 297                                 struct regmap *regmap)
 298 {
 299         struct device *dev = &pdev->dev;
 300         struct berlin_pinctrl *pctrl;
 301         int ret;
 302
 303         pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
 304         if (!pctrl)
 305                 return -ENOMEM;
 306
 307         platform_set_drvdata(pdev, pctrl);
 308
 309         pctrl->regmap = regmap;
 310         pctrl->dev = &pdev->dev;
 311         pctrl->desc = desc;
 312
 313         ret = berlin_pinctrl_build_state(pdev);
 314         if (ret) {
 315                 dev_err(dev, "cannot build driver state: %d\n", ret);
 316                 return ret;
 317         }
 318
 319         pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
 320         if (IS_ERR(pctrl->pctrl_dev)) {
 321                 dev_err(dev, "failed to register pinctrl driver\n");
 322                 return PTR_ERR(pctrl->pctrl_dev);
 323         }
 324
 325         return 0;
 326 }
 327
 328 int berlin_pinctrl_probe(struct platform_device *pdev,
 329                          const struct berlin_pinctrl_desc *desc)
 330 {
 331         struct device *dev = &pdev->dev;
 332         struct device_node *parent_np = of_get_parent(dev->of_node);
 333         struct regmap *regmap = syscon_node_to_regmap(parent_np);
 334
 335         of_node_put(parent_np);
 336         if (IS_ERR(regmap))
 337                 return PTR_ERR(regmap);
 338
 339         return berlin_pinctrl_probe_regmap(pdev, desc, regmap);
 340 }