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 TÃ©nart <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/module.h>
  15 #include <linux/of.h>
  16 #include <linux/of_address.h>
  17 #include <linux/of_device.h>
  18 #include <linux/pinctrl/pinctrl.h>
  19 #include <linux/pinctrl/pinmux.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/regmap.h>
  22 #include <linux/slab.h>
  23
  24 #include "../core.h"
  25 #include "../pinctrl-utils.h"
  26 #include "berlin.h"
  27
  28 struct berlin_pinctrl {
  29         struct regmap *regmap;
  30         struct device *dev;
  31         const struct berlin_pinctrl_desc *desc;
  32         struct berlin_pinctrl_function *functions;
  33         unsigned nfunctions;
  34         struct pinctrl_dev *pctrl_dev;
  35 };
  36
  37 static int berlin_pinctrl_get_group_count(struct pinctrl_dev *pctrl_dev)
  38 {
  39         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  40
  41         return pctrl->desc->ngroups;
  42 }
  43
  44 static const char *berlin_pinctrl_get_group_name(struct pinctrl_dev *pctrl_dev,
  45                                                  unsigned group)
  46 {
  47         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  48
  49         return pctrl->desc->groups[group].name;
  50 }
  51
  52 static int berlin_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrl_dev,
  53                                          struct device_node *node,
  54                                          struct pinctrl_map **map,
  55                                          unsigned *num_maps)
  56 {
  57         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
  58         struct property *prop;
  59         const char *function_name, *group_name;
  60         unsigned reserved_maps = 0;
  61         int ret, ngroups;
  62
  63         *map = NULL;
  64         *num_maps = 0;
  65
  66         ret = of_property_read_string(node, "function", &function_name);
  67         if (ret) {
  68                 dev_err(pctrl->dev,
  69                         "missing function property in node %s\n",
  70                         node->name);
  71                 return -EINVAL;
  72         }
  73
  74         ngroups = of_property_count_strings(node, "groups");
  75         if (ngroups < 0) {
  76                 dev_err(pctrl->dev,
  77                         "missing groups property in node %s\n",
  78                         node->name);
  79                 return -EINVAL;
  80         }
  81
  82         ret = pinctrl_utils_reserve_map(pctrl_dev, map, &reserved_maps,
  83                                         num_maps, ngroups);
  84         if (ret) {
  85                 dev_err(pctrl->dev, "can't reserve map: %d\n", ret);
  86                 return ret;
  87         }
  88
  89         of_property_for_each_string(node, "groups", prop, group_name) {
  90                 ret = pinctrl_utils_add_map_mux(pctrl_dev, map, &reserved_maps,
  91                                                 num_maps, group_name,
  92                                                 function_name);
  93                 if (ret) {
  94                         dev_err(pctrl->dev, "can't add map: %d\n", ret);
  95                         return ret;
  96                 }
  97         }
  98
  99         return 0;
 100 }
 101
 102 static void berlin_pinctrl_dt_free_map(struct pinctrl_dev *pctrl_dev,
 103                                        struct pinctrl_map *map,
 104                                        unsigned nmaps)
 105 {
 106         int i;
 107
 108         for (i = 0; i < nmaps; i++) {
 109                 if (map[i].type == PIN_MAP_TYPE_MUX_GROUP) {
 110                         kfree(map[i].data.mux.group);
 111
 112                         /* a function can be applied to multiple groups */
 113                         if (i == 0)
 114                                 kfree(map[i].data.mux.function);
 115                 }
 116         }
 117
 118         kfree(map);
 119 }
 120
 121 static const struct pinctrl_ops berlin_pinctrl_ops = {
 122         .get_groups_count       = &berlin_pinctrl_get_group_count,
 123         .get_group_name         = &berlin_pinctrl_get_group_name,
 124         .dt_node_to_map         = &berlin_pinctrl_dt_node_to_map,
 125         .dt_free_map            = &berlin_pinctrl_dt_free_map,
 126 };
 127
 128 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
 129 {
 130         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 131
 132         return pctrl->nfunctions;
 133 }
 134
 135 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
 136                                                    unsigned function)
 137 {
 138         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 139
 140         return pctrl->functions[function].name;
 141 }
 142
 143 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
 144                                              unsigned function,
 145                                              const char * const **groups,
 146                                              unsigned * const num_groups)
 147 {
 148         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 149
 150         *groups = pctrl->functions[function].groups;
 151         *num_groups = pctrl->functions[function].ngroups;
 152
 153         return 0;
 154 }
 155
 156 static struct berlin_desc_function *
 157 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
 158                                      const struct berlin_desc_group *group,
 159                                      const char *fname)
 160 {
 161         struct berlin_desc_function *function = group->functions;
 162
 163         while (function->name) {
 164                 if (!strcmp(function->name, fname))
 165                         return function;
 166
 167                 function++;
 168         }
 169
 170         return NULL;
 171 }
 172
 173 static int berlin_pinmux_enable(struct pinctrl_dev *pctrl_dev,
 174                                 unsigned function,
 175                                 unsigned group)
 176 {
 177         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 178         const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
 179         struct berlin_pinctrl_function *func = pctrl->functions + function;
 180         struct berlin_desc_function *function_desc =
 181                 berlin_pinctrl_find_function_by_name(pctrl, group_desc,
 182                                                      func->name);
 183         u32 mask, val;
 184
 185         if (!function_desc)
 186                 return -EINVAL;
 187
 188         mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
 189                        group_desc->lsb);
 190         val = function_desc->muxval << group_desc->lsb;
 191         regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
 192
 193         return 0;
 194 }
 195
 196 static const struct pinmux_ops berlin_pinmux_ops = {
 197         .get_functions_count    = &berlin_pinmux_get_functions_count,
 198         .get_function_name      = &berlin_pinmux_get_function_name,
 199         .get_function_groups    = &berlin_pinmux_get_function_groups,
 200         .enable                 = &berlin_pinmux_enable,
 201 };
 202
 203 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
 204                                        const char *name)
 205 {
 206         struct berlin_pinctrl_function *function = pctrl->functions;
 207
 208         while (function->name) {
 209                 if (!strcmp(function->name, name)) {
 210                         function->ngroups++;
 211                         return -EEXIST;
 212                 }
 213                 function++;
 214         }
 215
 216         function->name = name;
 217         function->ngroups = 1;
 218
 219         pctrl->nfunctions++;
 220
 221         return 0;
 222 }
 223
 224 static int berlin_pinctrl_build_state(struct platform_device *pdev)
 225 {
 226         struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
 227         struct berlin_desc_group const *desc_group;
 228         struct berlin_desc_function const *desc_function;
 229         int i, max_functions = 0;
 230
 231         pctrl->nfunctions = 0;
 232
 233         for (i = 0; i < pctrl->desc->ngroups; i++) {
 234                 desc_group = pctrl->desc->groups + i;
 235                 /* compute the maxiumum number of functions a group can have */
 236                 max_functions += 1 << (desc_group->bit_width + 1);
 237         }
 238
 239         /* we will reallocate later */
 240         pctrl->functions = devm_kzalloc(&pdev->dev,
 241                                         max_functions * sizeof(*pctrl->functions),
 242                                         GFP_KERNEL);
 243         if (!pctrl->functions)
 244                 return -ENOMEM;
 245
 246         /* register all functions */
 247         for (i = 0; i < pctrl->desc->ngroups; i++) {
 248                 desc_group = pctrl->desc->groups + i;
 249                 desc_function = desc_group->functions;
 250
 251                 while (desc_function->name) {
 252                         berlin_pinctrl_add_function(pctrl, desc_function->name);
 253                         desc_function++;
 254                 }
 255         }
 256
 257         pctrl->functions = krealloc(pctrl->functions,
 258                                     pctrl->nfunctions * sizeof(*pctrl->functions),
 259                                     GFP_KERNEL);
 260
 261         /* map functions to theirs groups */
 262         for (i = 0; i < pctrl->desc->ngroups; i++) {
 263                 desc_group = pctrl->desc->groups + i;
 264                 desc_function = desc_group->functions;
 265
 266                 while (desc_function->name) {
 267                         struct berlin_pinctrl_function
 268                                 *function = pctrl->functions;
 269                         const char **groups;
 270                         bool found = false;
 271
 272                         while (function->name) {
 273                                 if (!strcmp(desc_function->name, function->name)) {
 274                                         found = true;
 275                                         break;
 276                                 }
 277                                 function++;
 278                         }
 279
 280                         if (!found)
 281                                 return -EINVAL;
 282
 283                         if (!function->groups) {
 284                                 function->groups =
 285                                         devm_kzalloc(&pdev->dev,
 286                                                      function->ngroups * sizeof(char *),
 287                                                      GFP_KERNEL);
 288
 289                                 if (!function->groups)
 290                                         return -ENOMEM;
 291                         }
 292
 293                         groups = function->groups;
 294                         while (*groups)
 295                                 groups++;
 296
 297                         *groups = desc_group->name;
 298
 299                         desc_function++;
 300                 }
 301         }
 302
 303         return 0;
 304 }
 305
 306 static struct pinctrl_desc berlin_pctrl_desc = {
 307         .name           = "berlin-pinctrl",
 308         .pctlops        = &berlin_pinctrl_ops,
 309         .pmxops         = &berlin_pinmux_ops,
 310         .owner          = THIS_MODULE,
 311 };
 312
 313 int berlin_pinctrl_probe(struct platform_device *pdev,
 314                          const struct berlin_pinctrl_desc *desc)
 315 {
 316         struct device *dev = &pdev->dev;
 317         struct berlin_pinctrl *pctrl;
 318         struct regmap *regmap;
 319         int ret;
 320
 321         regmap = dev_get_regmap(&pdev->dev, NULL);
 322         if (!regmap)
 323                 return PTR_ERR(regmap);
 324
 325         pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
 326         if (!pctrl)
 327                 return -ENOMEM;
 328
 329         platform_set_drvdata(pdev, pctrl);
 330
 331         pctrl->regmap = regmap;
 332         pctrl->dev = &pdev->dev;
 333         pctrl->desc = desc;
 334
 335         ret = berlin_pinctrl_build_state(pdev);
 336         if (ret) {
 337                 dev_err(dev, "cannot build driver state: %d\n", ret);
 338                 return ret;
 339         }
 340
 341         pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
 342         if (!pctrl->pctrl_dev) {
 343                 dev_err(dev, "failed to register pinctrl driver\n");
 344                 return -EINVAL;
 345         }
 346
 347         return 0;
 348 }