kernel/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 const struct pinctrl_ops berlin_pinctrl_ops = {
 103         .get_groups_count       = &berlin_pinctrl_get_group_count,
 104         .get_group_name         = &berlin_pinctrl_get_group_name,
 105         .dt_node_to_map         = &berlin_pinctrl_dt_node_to_map,
 106         .dt_free_map            = &pinctrl_utils_dt_free_map,
 107 };
 108
 109 static int berlin_pinmux_get_functions_count(struct pinctrl_dev *pctrl_dev)
 110 {
 111         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 112
 113         return pctrl->nfunctions;
 114 }
 115
 116 static const char *berlin_pinmux_get_function_name(struct pinctrl_dev *pctrl_dev,
 117                                                    unsigned function)
 118 {
 119         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 120
 121         return pctrl->functions[function].name;
 122 }
 123
 124 static int berlin_pinmux_get_function_groups(struct pinctrl_dev *pctrl_dev,
 125                                              unsigned function,
 126                                              const char * const **groups,
 127                                              unsigned * const num_groups)
 128 {
 129         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 130
 131         *groups = pctrl->functions[function].groups;
 132         *num_groups = pctrl->functions[function].ngroups;
 133
 134         return 0;
 135 }
 136
 137 static struct berlin_desc_function *
 138 berlin_pinctrl_find_function_by_name(struct berlin_pinctrl *pctrl,
 139                                      const struct berlin_desc_group *group,
 140                                      const char *fname)
 141 {
 142         struct berlin_desc_function *function = group->functions;
 143
 144         while (function->name) {
 145                 if (!strcmp(function->name, fname))
 146                         return function;
 147
 148                 function++;
 149         }
 150
 151         return NULL;
 152 }
 153
 154 static int berlin_pinmux_set(struct pinctrl_dev *pctrl_dev,
 155                              unsigned function,
 156                              unsigned group)
 157 {
 158         struct berlin_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctrl_dev);
 159         const struct berlin_desc_group *group_desc = pctrl->desc->groups + group;
 160         struct berlin_pinctrl_function *func = pctrl->functions + function;
 161         struct berlin_desc_function *function_desc =
 162                 berlin_pinctrl_find_function_by_name(pctrl, group_desc,
 163                                                      func->name);
 164         u32 mask, val;
 165
 166         if (!function_desc)
 167                 return -EINVAL;
 168
 169         mask = GENMASK(group_desc->lsb + group_desc->bit_width - 1,
 170                        group_desc->lsb);
 171         val = function_desc->muxval << group_desc->lsb;
 172         regmap_update_bits(pctrl->regmap, group_desc->offset, mask, val);
 173
 174         return 0;
 175 }
 176
 177 static const struct pinmux_ops berlin_pinmux_ops = {
 178         .get_functions_count    = &berlin_pinmux_get_functions_count,
 179         .get_function_name      = &berlin_pinmux_get_function_name,
 180         .get_function_groups    = &berlin_pinmux_get_function_groups,
 181         .set_mux                = &berlin_pinmux_set,
 182 };
 183
 184 static int berlin_pinctrl_add_function(struct berlin_pinctrl *pctrl,
 185                                        const char *name)
 186 {
 187         struct berlin_pinctrl_function *function = pctrl->functions;
 188
 189         while (function->name) {
 190                 if (!strcmp(function->name, name)) {
 191                         function->ngroups++;
 192                         return -EEXIST;
 193                 }
 194                 function++;
 195         }
 196
 197         function->name = name;
 198         function->ngroups = 1;
 199
 200         pctrl->nfunctions++;
 201
 202         return 0;
 203 }
 204
 205 static int berlin_pinctrl_build_state(struct platform_device *pdev)
 206 {
 207         struct berlin_pinctrl *pctrl = platform_get_drvdata(pdev);
 208         struct berlin_desc_group const *desc_group;
 209         struct berlin_desc_function const *desc_function;
 210         int i, max_functions = 0;
 211
 212         pctrl->nfunctions = 0;
 213
 214         for (i = 0; i < pctrl->desc->ngroups; i++) {
 215                 desc_group = pctrl->desc->groups + i;
 216                 /* compute the maxiumum number of functions a group can have */
 217                 max_functions += 1 << (desc_group->bit_width + 1);
 218         }
 219
 220         /* we will reallocate later */
 221         pctrl->functions = devm_kzalloc(&pdev->dev,
 222                                         max_functions * sizeof(*pctrl->functions),
 223                                         GFP_KERNEL);
 224         if (!pctrl->functions)
 225                 return -ENOMEM;
 226
 227         /* register all functions */
 228         for (i = 0; i < pctrl->desc->ngroups; i++) {
 229                 desc_group = pctrl->desc->groups + i;
 230                 desc_function = desc_group->functions;
 231
 232                 while (desc_function->name) {
 233                         berlin_pinctrl_add_function(pctrl, desc_function->name);
 234                         desc_function++;
 235                 }
 236         }
 237
 238         pctrl->functions = krealloc(pctrl->functions,
 239                                     pctrl->nfunctions * sizeof(*pctrl->functions),
 240                                     GFP_KERNEL);
 241
 242         /* map functions to theirs groups */
 243         for (i = 0; i < pctrl->desc->ngroups; i++) {
 244                 desc_group = pctrl->desc->groups + i;
 245                 desc_function = desc_group->functions;
 246
 247                 while (desc_function->name) {
 248                         struct berlin_pinctrl_function
 249                                 *function = pctrl->functions;
 250                         const char **groups;
 251                         bool found = false;
 252
 253                         while (function->name) {
 254                                 if (!strcmp(desc_function->name, function->name)) {
 255                                         found = true;
 256                                         break;
 257                                 }
 258                                 function++;
 259                         }
 260
 261                         if (!found)
 262                                 return -EINVAL;
 263
 264                         if (!function->groups) {
 265                                 function->groups =
 266                                         devm_kzalloc(&pdev->dev,
 267                                                      function->ngroups * sizeof(char *),
 268                                                      GFP_KERNEL);
 269
 270                                 if (!function->groups)
 271                                         return -ENOMEM;
 272                         }
 273
 274                         groups = function->groups;
 275                         while (*groups)
 276                                 groups++;
 277
 278                         *groups = desc_group->name;
 279
 280                         desc_function++;
 281                 }
 282         }
 283
 284         return 0;
 285 }
 286
 287 static struct pinctrl_desc berlin_pctrl_desc = {
 288         .name           = "berlin-pinctrl",
 289         .pctlops        = &berlin_pinctrl_ops,
 290         .pmxops         = &berlin_pinmux_ops,
 291         .owner          = THIS_MODULE,
 292 };
 293
 294 int berlin_pinctrl_probe(struct platform_device *pdev,
 295                          const struct berlin_pinctrl_desc *desc)
 296 {
 297         struct device *dev = &pdev->dev;
 298         struct berlin_pinctrl *pctrl;
 299         struct regmap *regmap;
 300         int ret;
 301
 302         regmap = dev_get_regmap(&pdev->dev, NULL);
 303         if (!regmap)
 304                 return -ENODEV;
 305
 306         pctrl = devm_kzalloc(dev, sizeof(*pctrl), GFP_KERNEL);
 307         if (!pctrl)
 308                 return -ENOMEM;
 309
 310         platform_set_drvdata(pdev, pctrl);
 311
 312         pctrl->regmap = regmap;
 313         pctrl->dev = &pdev->dev;
 314         pctrl->desc = desc;
 315
 316         ret = berlin_pinctrl_build_state(pdev);
 317         if (ret) {
 318                 dev_err(dev, "cannot build driver state: %d\n", ret);
 319                 return ret;
 320         }
 321
 322         pctrl->pctrl_dev = pinctrl_register(&berlin_pctrl_desc, dev, pctrl);
 323         if (!pctrl->pctrl_dev) {
 324                 dev_err(dev, "failed to register pinctrl driver\n");
 325                 return -EINVAL;
 326         }
 327
 328         return 0;
 329 }