drivers/pinctrl/pinconf.c

   1 /*
   2  * Core driver for the pin config portions of the pin control subsystem
   3  *
   4  * Copyright (C) 2011 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  *
   7  * Author: Linus Walleij <linus.walleij@linaro.org>
   8  *
   9  * License terms: GNU General Public License (GPL) version 2
  10  */
  11 #define pr_fmt(fmt) "pinconfig core: " fmt
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/slab.h>
  18 #include <linux/debugfs.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/pinctrl/machine.h>
  21 #include <linux/pinctrl/pinctrl.h>
  22 #include <linux/pinctrl/pinconf.h>
  23 #include "core.h"
  24 #include "pinconf.h"
  25
  26 int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
  27                            unsigned long *config)
  28 {
  29         const struct pinconf_ops *ops = pctldev->desc->confops;
  30
  31         if (!ops || !ops->pin_config_get) {
  32                 dev_err(pctldev->dev, "cannot get pin configuration, missing "
  33                         "pin_config_get() function in driver\n");
  34                 return -EINVAL;
  35         }
  36
  37         return ops->pin_config_get(pctldev, pin, config);
  38 }
  39
  40 /**
  41  * pin_config_get() - get the configuration of a single pin parameter
  42  * @dev_name: name of the pin controller device for this pin
  43  * @name: name of the pin to get the config for
  44  * @config: the config pointed to by this argument will be filled in with the
  45  *      current pin state, it can be used directly by drivers as a numeral, or
  46  *      it can be dereferenced to any struct.
  47  */
  48 int pin_config_get(const char *dev_name, const char *name,
  49                           unsigned long *config)
  50 {
  51         struct pinctrl_dev *pctldev;
  52         int pin;
  53
  54         pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
  55         if (!pctldev)
  56                 return -EINVAL;
  57
  58         pin = pin_get_from_name(pctldev, name);
  59         if (pin < 0)
  60                 return pin;
  61
  62         return pin_config_get_for_pin(pctldev, pin, config);
  63 }
  64 EXPORT_SYMBOL(pin_config_get);
  65
  66 int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
  67                            unsigned long config)
  68 {
  69         const struct pinconf_ops *ops = pctldev->desc->confops;
  70         int ret;
  71
  72         if (!ops || !ops->pin_config_set) {
  73                 dev_err(pctldev->dev, "cannot configure pin, missing "
  74                         "config function in driver\n");
  75                 return -EINVAL;
  76         }
  77
  78         ret = ops->pin_config_set(pctldev, pin, config);
  79         if (ret) {
  80                 dev_err(pctldev->dev,
  81                         "unable to set pin configuration on pin %d\n", pin);
  82                 return ret;
  83         }
  84
  85         return 0;
  86 }
  87
  88 /**
  89  * pin_config_set() - set the configuration of a single pin parameter
  90  * @dev_name: name of pin controller device for this pin
  91  * @name: name of the pin to set the config for
  92  * @config: the config in this argument will contain the desired pin state, it
  93  *      can be used directly by drivers as a numeral, or it can be dereferenced
  94  *      to any struct.
  95  */
  96 int pin_config_set(const char *dev_name, const char *name,
  97                    unsigned long config)
  98 {
  99         struct pinctrl_dev *pctldev;
 100         int pin;
 101
 102         pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
 103         if (!pctldev)
 104                 return -EINVAL;
 105
 106         pin = pin_get_from_name(pctldev, name);
 107         if (pin < 0)
 108                 return pin;
 109
 110         return pin_config_set_for_pin(pctldev, pin, config);
 111 }
 112 EXPORT_SYMBOL(pin_config_set);
 113
 114 int pin_config_group_get(const char *dev_name, const char *pin_group,
 115                          unsigned long *config)
 116 {
 117         struct pinctrl_dev *pctldev;
 118         const struct pinconf_ops *ops;
 119         int selector;
 120
 121         pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
 122         if (!pctldev)
 123                 return -EINVAL;
 124         ops = pctldev->desc->confops;
 125
 126         if (!ops || !ops->pin_config_group_get) {
 127                 dev_err(pctldev->dev, "cannot get configuration for pin "
 128                         "group, missing group config get function in "
 129                         "driver\n");
 130                 return -EINVAL;
 131         }
 132
 133         selector = pinctrl_get_group_selector(pctldev, pin_group);
 134         if (selector < 0)
 135                 return selector;
 136
 137         return ops->pin_config_group_get(pctldev, selector, config);
 138 }
 139 EXPORT_SYMBOL(pin_config_group_get);
 140
 141
 142 int pin_config_group_set(const char *dev_name, const char *pin_group,
 143                          unsigned long config)
 144 {
 145         struct pinctrl_dev *pctldev;
 146         const struct pinconf_ops *ops;
 147         const struct pinctrl_ops *pctlops;
 148         int selector;
 149         const unsigned *pins;
 150         unsigned num_pins;
 151         int ret;
 152         int i;
 153
 154         pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
 155         if (!pctldev)
 156                 return -EINVAL;
 157         ops = pctldev->desc->confops;
 158         pctlops = pctldev->desc->pctlops;
 159
 160         if (!ops || (!ops->pin_config_group_set && !ops->pin_config_set)) {
 161                 dev_err(pctldev->dev, "cannot configure pin group, missing "
 162                         "config function in driver\n");
 163                 return -EINVAL;
 164         }
 165
 166         selector = pinctrl_get_group_selector(pctldev, pin_group);
 167         if (selector < 0)
 168                 return selector;
 169
 170         ret = pctlops->get_group_pins(pctldev, selector, &pins, &num_pins);
 171         if (ret) {
 172                 dev_err(pctldev->dev, "cannot configure pin group, error "
 173                         "getting pins\n");
 174                 return ret;
 175         }
 176
 177         /*
 178          * If the pin controller supports handling entire groups we use that
 179          * capability.
 180          */
 181         if (ops->pin_config_group_set) {
 182                 ret = ops->pin_config_group_set(pctldev, selector, config);
 183                 /*
 184                  * If the pin controller prefer that a certain group be handled
 185                  * pin-by-pin as well, it returns -EAGAIN.
 186                  */
 187                 if (ret != -EAGAIN)
 188                         return ret;
 189         }
 190
 191         /*
 192          * If the controller cannot handle entire groups, we configure each pin
 193          * individually.
 194          */
 195         if (!ops->pin_config_set)
 196                 return 0;
 197
 198         for (i = 0; i < num_pins; i++) {
 199                 ret = ops->pin_config_set(pctldev, pins[i], config);
 200                 if (ret < 0)
 201                         return ret;
 202         }
 203
 204         return 0;
 205 }
 206 EXPORT_SYMBOL(pin_config_group_set);
 207
 208 int pinconf_check_ops(const struct pinconf_ops *ops)
 209 {
 210         /* We must be able to read out pin status */
 211         if (!ops->pin_config_get && !ops->pin_config_group_get)
 212                 return -EINVAL;
 213         /* We have to be able to config the pins in SOME way */
 214         if (!ops->pin_config_set && !ops->pin_config_group_set)
 215                 return -EINVAL;
 216         return 0;
 217 }
 218
 219 #ifdef CONFIG_DEBUG_FS
 220
 221 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 222                              struct seq_file *s, int pin)
 223 {
 224         const struct pinconf_ops *ops = pctldev->desc->confops;
 225
 226         if (ops && ops->pin_config_dbg_show)
 227                 ops->pin_config_dbg_show(pctldev, s, pin);
 228 }
 229
 230 static int pinconf_pins_show(struct seq_file *s, void *what)
 231 {
 232         struct pinctrl_dev *pctldev = s->private;
 233         unsigned i, pin;
 234
 235         seq_puts(s, "Pin config settings per pin\n");
 236         seq_puts(s, "Format: pin (name): pinmux setting array\n");
 237
 238         /* The pin number can be retrived from the pin controller descriptor */
 239         for (i = 0; pin < pctldev->desc->npins; i++) {
 240                 struct pin_desc *desc;
 241
 242                 pin = pctldev->desc->pins[i].number;
 243                 desc = pin_desc_get(pctldev, pin);
 244                 /* Skip if we cannot search the pin */
 245                 if (desc == NULL)
 246                         continue;
 247
 248                 seq_printf(s, "pin %d (%s):", pin,
 249                            desc->name ? desc->name : "unnamed");
 250
 251                 pinconf_dump_pin(pctldev, s, pin);
 252
 253                 seq_printf(s, "\n");
 254         }
 255
 256         return 0;
 257 }
 258
 259 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 260                                struct seq_file *s, unsigned selector,
 261                                const char *gname)
 262 {
 263         const struct pinconf_ops *ops = pctldev->desc->confops;
 264
 265         if (ops && ops->pin_config_group_dbg_show)
 266                 ops->pin_config_group_dbg_show(pctldev, s, selector);
 267 }
 268
 269 static int pinconf_groups_show(struct seq_file *s, void *what)
 270 {
 271         struct pinctrl_dev *pctldev = s->private;
 272         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 273         const struct pinconf_ops *ops = pctldev->desc->confops;
 274         unsigned selector = 0;
 275
 276         if (!ops || !ops->pin_config_group_get)
 277                 return 0;
 278
 279         seq_puts(s, "Pin config settings per pin group\n");
 280         seq_puts(s, "Format: group (name): pinmux setting array\n");
 281
 282         while (pctlops->list_groups(pctldev, selector) >= 0) {
 283                 const char *gname = pctlops->get_group_name(pctldev, selector);
 284
 285                 seq_printf(s, "%u (%s):", selector, gname);
 286                 pinconf_dump_group(pctldev, s, selector, gname);
 287                 selector++;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int pinconf_pins_open(struct inode *inode, struct file *file)
 294 {
 295         return single_open(file, pinconf_pins_show, inode->i_private);
 296 }
 297
 298 static int pinconf_groups_open(struct inode *inode, struct file *file)
 299 {
 300         return single_open(file, pinconf_groups_show, inode->i_private);
 301 }
 302
 303 static const struct file_operations pinconf_pins_ops = {
 304         .open           = pinconf_pins_open,
 305         .read           = seq_read,
 306         .llseek         = seq_lseek,
 307         .release        = single_release,
 308 };
 309
 310 static const struct file_operations pinconf_groups_ops = {
 311         .open           = pinconf_groups_open,
 312         .read           = seq_read,
 313         .llseek         = seq_lseek,
 314         .release        = single_release,
 315 };
 316
 317 void pinconf_init_device_debugfs(struct dentry *devroot,
 318                          struct pinctrl_dev *pctldev)
 319 {
 320         debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
 321                             devroot, pctldev, &pinconf_pins_ops);
 322         debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
 323                             devroot, pctldev, &pinconf_groups_ops);
 324 }
 325
 326 #endif