drivers/sh/pfc/gpio.c

   1 /*
   2  * SuperH Pin Function Controller GPIO driver.
   3  *
   4  * Copyright (C) 2008 Magnus Damm
   5  * Copyright (C) 2009 - 2012 Paul Mundt
   6  *
   7  * This file is subject to the terms and conditions of the GNU General Public
   8  * License.  See the file "COPYING" in the main directory of this archive
   9  * for more details.
  10  */
  11 #define pr_fmt(fmt) "sh_pfc " KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/init.h>
  14 #include <linux/gpio.h>
  15 #include <linux/slab.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/pinctrl/consumer.h>
  20 #include <linux/sh_pfc.h>
  21
  22 struct sh_pfc_chip {
  23         struct sh_pfc           *pfc;
  24         struct gpio_chip        gpio_chip;
  25 };
  26
  27 static struct sh_pfc_chip *gpio_to_pfc_chip(struct gpio_chip *gc)
  28 {
  29         return container_of(gc, struct sh_pfc_chip, gpio_chip);
  30 }
  31
  32 static struct sh_pfc *gpio_to_pfc(struct gpio_chip *gc)
  33 {
  34         return gpio_to_pfc_chip(gc)->pfc;
  35 }
  36
  37 static int sh_gpio_request(struct gpio_chip *gc, unsigned offset)
  38 {
  39         return pinctrl_request_gpio(offset);
  40 }
  41
  42 static void sh_gpio_free(struct gpio_chip *gc, unsigned offset)
  43 {
  44         pinctrl_free_gpio(offset);
  45 }
  46
  47 static void sh_gpio_set_value(struct sh_pfc *pfc, unsigned gpio, int value)
  48 {
  49         struct pinmux_data_reg *dr = NULL;
  50         int bit = 0;
  51
  52         if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
  53                 BUG();
  54         else
  55                 sh_pfc_write_bit(dr, bit, value);
  56 }
  57
  58 static int sh_gpio_get_value(struct sh_pfc *pfc, unsigned gpio)
  59 {
  60         struct pinmux_data_reg *dr = NULL;
  61         int bit = 0;
  62
  63         if (!pfc || sh_pfc_get_data_reg(pfc, gpio, &dr, &bit) != 0)
  64                 return -EINVAL;
  65
  66         return sh_pfc_read_bit(dr, bit);
  67 }
  68
  69 static int sh_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
  70 {
  71         return pinctrl_gpio_direction_input(offset);
  72 }
  73
  74 static int sh_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
  75                                     int value)
  76 {
  77         sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
  78
  79         return pinctrl_gpio_direction_output(offset);
  80 }
  81
  82 static int sh_gpio_get(struct gpio_chip *gc, unsigned offset)
  83 {
  84         return sh_gpio_get_value(gpio_to_pfc(gc), offset);
  85 }
  86
  87 static void sh_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
  88 {
  89         sh_gpio_set_value(gpio_to_pfc(gc), offset, value);
  90 }
  91
  92 static int sh_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
  93 {
  94         struct sh_pfc *pfc = gpio_to_pfc(gc);
  95         pinmux_enum_t enum_id;
  96         pinmux_enum_t *enum_ids;
  97         int i, k, pos;
  98
  99         pos = 0;
 100         enum_id = 0;
 101         while (1) {
 102                 pos = sh_pfc_gpio_to_enum(pfc, offset, pos, &enum_id);
 103                 if (pos <= 0 || !enum_id)
 104                         break;
 105
 106                 for (i = 0; i < pfc->gpio_irq_size; i++) {
 107                         enum_ids = pfc->gpio_irq[i].enum_ids;
 108                         for (k = 0; enum_ids[k]; k++) {
 109                                 if (enum_ids[k] == enum_id)
 110                                         return pfc->gpio_irq[i].irq;
 111                         }
 112                 }
 113         }
 114
 115         return -ENOSYS;
 116 }
 117
 118 static void sh_pfc_gpio_setup(struct sh_pfc_chip *chip)
 119 {
 120         struct sh_pfc *pfc = chip->pfc;
 121         struct gpio_chip *gc = &chip->gpio_chip;
 122
 123         gc->request = sh_gpio_request;
 124         gc->free = sh_gpio_free;
 125         gc->direction_input = sh_gpio_direction_input;
 126         gc->get = sh_gpio_get;
 127         gc->direction_output = sh_gpio_direction_output;
 128         gc->set = sh_gpio_set;
 129         gc->to_irq = sh_gpio_to_irq;
 130
 131         WARN_ON(pfc->first_gpio != 0); /* needs testing */
 132
 133         gc->label = pfc->name;
 134         gc->owner = THIS_MODULE;
 135         gc->base = pfc->first_gpio;
 136         gc->ngpio = (pfc->last_gpio - pfc->first_gpio) + 1;
 137 }
 138
 139 int sh_pfc_register_gpiochip(struct sh_pfc *pfc)
 140 {
 141         struct sh_pfc_chip *chip;
 142         int ret;
 143
 144         chip = kzalloc(sizeof(struct sh_pfc_chip), GFP_KERNEL);
 145         if (unlikely(!chip))
 146                 return -ENOMEM;
 147
 148         chip->pfc = pfc;
 149
 150         sh_pfc_gpio_setup(chip);
 151
 152         ret = gpiochip_add(&chip->gpio_chip);
 153         if (unlikely(ret < 0))
 154                 kfree(chip);
 155
 156         pr_info("%s handling gpio %d -> %d\n",
 157                 pfc->name, pfc->first_gpio, pfc->last_gpio);
 158
 159         return ret;
 160 }
 161 EXPORT_SYMBOL_GPL(sh_pfc_register_gpiochip);
 162
 163 static int sh_pfc_gpio_match(struct gpio_chip *gc, void *data)
 164 {
 165         return !!strstr(gc->label, data);
 166 }
 167
 168 static int sh_pfc_gpio_probe(struct platform_device *pdev)
 169 {
 170         struct sh_pfc_chip *chip;
 171         struct gpio_chip *gc;
 172
 173         gc = gpiochip_find("_pfc", sh_pfc_gpio_match);
 174         if (unlikely(!gc)) {
 175                 pr_err("Cant find gpio chip\n");
 176                 return -ENODEV;
 177         }
 178
 179         chip = gpio_to_pfc_chip(gc);
 180         platform_set_drvdata(pdev, chip);
 181
 182         pr_info("attaching to GPIO chip %s\n", chip->pfc->name);
 183
 184         return 0;
 185 }
 186
 187 static int sh_pfc_gpio_remove(struct platform_device *pdev)
 188 {
 189         struct sh_pfc_chip *chip = platform_get_drvdata(pdev);
 190         int ret;
 191
 192         ret = gpiochip_remove(&chip->gpio_chip);
 193         if (unlikely(ret < 0))
 194                 return ret;
 195
 196         kfree(chip);
 197         return 0;
 198 }
 199
 200 static struct platform_driver sh_pfc_gpio_driver = {
 201         .probe          = sh_pfc_gpio_probe,
 202         .remove         = sh_pfc_gpio_remove,
 203         .driver         = {
 204                 .name   = KBUILD_MODNAME,
 205                 .owner  = THIS_MODULE,
 206         },
 207 };
 208
 209 static struct platform_device sh_pfc_gpio_device = {
 210         .name           = KBUILD_MODNAME,
 211         .id             = -1,
 212 };
 213
 214 static int __init sh_pfc_gpio_init(void)
 215 {
 216         int rc;
 217
 218         rc = platform_driver_register(&sh_pfc_gpio_driver);
 219         if (likely(!rc)) {
 220                 rc = platform_device_register(&sh_pfc_gpio_device);
 221                 if (unlikely(rc))
 222                         platform_driver_unregister(&sh_pfc_gpio_driver);
 223         }
 224
 225         return rc;
 226 }
 227
 228 static void __exit sh_pfc_gpio_exit(void)
 229 {
 230         platform_device_unregister(&sh_pfc_gpio_device);
 231         platform_driver_unregister(&sh_pfc_gpio_driver);
 232 }
 233
 234 module_init(sh_pfc_gpio_init);
 235 module_exit(sh_pfc_gpio_exit);
 236
 237 MODULE_AUTHOR("Magnus Damm, Paul Mundt");
 238 MODULE_DESCRIPTION("GPIO driver for SuperH pin function controller");
 239 MODULE_LICENSE("GPL v2");
 240 MODULE_ALIAS("platform:pfc-gpio");