drivers/pinctrl/pinctrl-digicolor.c

   1 /*
   2  *  Driver for Conexant Digicolor General Purpose Pin Mapping
   3  *
   4  * Author: Baruch Siach <baruch@tkos.co.il>
   5  *
   6  * Copyright (C) 2015 Paradox Innovation Ltd.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * TODO:
  14  * - GPIO interrupt support
  15  * - Pin pad configuration (pull up/down, strength)
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/io.h>
  23 #include <linux/gpio.h>
  24 #include <linux/gpio/driver.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/pinctrl/machine.h>
  27 #include <linux/pinctrl/pinconf.h>
  28 #include <linux/pinctrl/pinconf-generic.h>
  29 #include <linux/pinctrl/pinctrl.h>
  30 #include <linux/pinctrl/pinmux.h>
  31 #include "pinctrl-utils.h"
  32
  33 #define DRIVER_NAME     "pinctrl-digicolor"
  34
  35 #define GP_CLIENTSEL(clct)      ((clct)*8 + 0x20)
  36 #define GP_DRIVE0(clct)         (GP_CLIENTSEL(clct) + 2)
  37 #define GP_OUTPUT0(clct)        (GP_CLIENTSEL(clct) + 3)
  38 #define GP_INPUT(clct)          (GP_CLIENTSEL(clct) + 6)
  39
  40 #define PIN_COLLECTIONS         ('R' - 'A' + 1)
  41 #define PINS_PER_COLLECTION     8
  42 #define PINS_COUNT              (PIN_COLLECTIONS * PINS_PER_COLLECTION)
  43
  44 struct dc_pinmap {
  45         void __iomem            *regs;
  46         struct device           *dev;
  47         struct pinctrl_dev      *pctl;
  48
  49         struct pinctrl_desc     *desc;
  50         const char              *pin_names[PINS_COUNT];
  51
  52         struct gpio_chip        chip;
  53         spinlock_t              lock;
  54 };
  55
  56 static int dc_get_groups_count(struct pinctrl_dev *pctldev)
  57 {
  58         return PINS_COUNT;
  59 }
  60
  61 static const char *dc_get_group_name(struct pinctrl_dev *pctldev,
  62                                      unsigned selector)
  63 {
  64         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  65
  66         /* Exactly one group per pin */
  67         return pmap->desc->pins[selector].name;
  68 }
  69
  70 static int dc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
  71                              const unsigned **pins,
  72                              unsigned *num_pins)
  73 {
  74         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  75
  76         *pins = &pmap->desc->pins[selector].number;
  77         *num_pins = 1;
  78
  79         return 0;
  80 }
  81
  82 static struct pinctrl_ops dc_pinctrl_ops = {
  83         .get_groups_count       = dc_get_groups_count,
  84         .get_group_name         = dc_get_group_name,
  85         .get_group_pins         = dc_get_group_pins,
  86         .dt_node_to_map         = pinconf_generic_dt_node_to_map_pin,
  87         .dt_free_map            = pinctrl_utils_dt_free_map,
  88 };
  89
  90 static const char *const dc_functions[] = {
  91         "gpio",
  92         "client_a",
  93         "client_b",
  94         "client_c",
  95 };
  96
  97 static int dc_get_functions_count(struct pinctrl_dev *pctldev)
  98 {
  99         return ARRAY_SIZE(dc_functions);
 100 }
 101
 102 static const char *dc_get_fname(struct pinctrl_dev *pctldev, unsigned selector)
 103 {
 104         return dc_functions[selector];
 105 }
 106
 107 static int dc_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
 108                          const char * const **groups,
 109                          unsigned * const num_groups)
 110 {
 111         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 112
 113         *groups = pmap->pin_names;
 114         *num_groups = PINS_COUNT;
 115
 116         return 0;
 117 }
 118
 119 static void dc_client_sel(int pin_num, int *reg, int *bit)
 120 {
 121         *bit = (pin_num % PINS_PER_COLLECTION) * 2;
 122         *reg = GP_CLIENTSEL(pin_num/PINS_PER_COLLECTION);
 123
 124         if (*bit >= PINS_PER_COLLECTION) {
 125                 *bit -= PINS_PER_COLLECTION;
 126                 *reg += 1;
 127         }
 128 }
 129
 130 static int dc_set_mux(struct pinctrl_dev *pctldev, unsigned selector,
 131                       unsigned group)
 132 {
 133         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 134         int bit_off, reg_off;
 135         u8 reg;
 136
 137         dc_client_sel(group, &reg_off, &bit_off);
 138
 139         reg = readb_relaxed(pmap->regs + reg_off);
 140         reg &= ~(3 << bit_off);
 141         reg |= (selector << bit_off);
 142         writeb_relaxed(reg, pmap->regs + reg_off);
 143
 144         return 0;
 145 }
 146
 147 static int dc_pmx_request_gpio(struct pinctrl_dev *pcdev,
 148                                struct pinctrl_gpio_range *range,
 149                                unsigned offset)
 150 {
 151         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pcdev);
 152         int bit_off, reg_off;
 153         u8 reg;
 154
 155         dc_client_sel(offset, &reg_off, &bit_off);
 156
 157         reg = readb_relaxed(pmap->regs + reg_off);
 158         if ((reg & (3 << bit_off)) != 0)
 159                 return -EBUSY;
 160
 161         return 0;
 162 }
 163
 164 static struct pinmux_ops dc_pmxops = {
 165         .get_functions_count    = dc_get_functions_count,
 166         .get_function_name      = dc_get_fname,
 167         .get_function_groups    = dc_get_groups,
 168         .set_mux                = dc_set_mux,
 169         .gpio_request_enable    = dc_pmx_request_gpio,
 170 };
 171
 172 static int dc_gpio_request(struct gpio_chip *chip, unsigned gpio)
 173 {
 174         return pinctrl_request_gpio(chip->base + gpio);
 175 }
 176
 177 static void dc_gpio_free(struct gpio_chip *chip, unsigned gpio)
 178 {
 179         pinctrl_free_gpio(chip->base + gpio);
 180 }
 181
 182 static int dc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 183 {
 184         struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip);
 185         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 186         int bit_off = gpio % PINS_PER_COLLECTION;
 187         u8 drive;
 188         unsigned long flags;
 189
 190         spin_lock_irqsave(&pmap->lock, flags);
 191         drive = readb_relaxed(pmap->regs + reg_off);
 192         drive &= ~BIT(bit_off);
 193         writeb_relaxed(drive, pmap->regs + reg_off);
 194         spin_unlock_irqrestore(&pmap->lock, flags);
 195
 196         return 0;
 197 }
 198
 199 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value);
 200
 201 static int dc_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 202                                     int value)
 203 {
 204         struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip);
 205         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 206         int bit_off = gpio % PINS_PER_COLLECTION;
 207         u8 drive;
 208         unsigned long flags;
 209
 210         dc_gpio_set(chip, gpio, value);
 211
 212         spin_lock_irqsave(&pmap->lock, flags);
 213         drive = readb_relaxed(pmap->regs + reg_off);
 214         drive |= BIT(bit_off);
 215         writeb_relaxed(drive, pmap->regs + reg_off);
 216         spin_unlock_irqrestore(&pmap->lock, flags);
 217
 218         return 0;
 219 }
 220
 221 static int dc_gpio_get(struct gpio_chip *chip, unsigned gpio)
 222 {
 223         struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip);
 224         int reg_off = GP_INPUT(gpio/PINS_PER_COLLECTION);
 225         int bit_off = gpio % PINS_PER_COLLECTION;
 226         u8 input;
 227
 228         input = readb_relaxed(pmap->regs + reg_off);
 229
 230         return !!(input & BIT(bit_off));
 231 }
 232
 233 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 234 {
 235         struct dc_pinmap *pmap = container_of(chip, struct dc_pinmap, chip);
 236         int reg_off = GP_OUTPUT0(gpio/PINS_PER_COLLECTION);
 237         int bit_off = gpio % PINS_PER_COLLECTION;
 238         u8 output;
 239         unsigned long flags;
 240
 241         spin_lock_irqsave(&pmap->lock, flags);
 242         output = readb_relaxed(pmap->regs + reg_off);
 243         if (value)
 244                 output |= BIT(bit_off);
 245         else
 246                 output &= ~BIT(bit_off);
 247         writeb_relaxed(output, pmap->regs + reg_off);
 248         spin_unlock_irqrestore(&pmap->lock, flags);
 249 }
 250
 251 static int dc_gpiochip_add(struct dc_pinmap *pmap, struct device_node *np)
 252 {
 253         struct gpio_chip *chip = &pmap->chip;
 254         int ret;
 255
 256         chip->label             = DRIVER_NAME;
 257         chip->dev               = pmap->dev;
 258         chip->request           = dc_gpio_request;
 259         chip->free              = dc_gpio_free;
 260         chip->direction_input   = dc_gpio_direction_input;
 261         chip->direction_output  = dc_gpio_direction_output;
 262         chip->get               = dc_gpio_get;
 263         chip->set               = dc_gpio_set;
 264         chip->base              = -1;
 265         chip->ngpio             = PINS_COUNT;
 266         chip->of_node           = np;
 267         chip->of_gpio_n_cells   = 2;
 268
 269         spin_lock_init(&pmap->lock);
 270
 271         ret = gpiochip_add(chip);
 272         if (ret < 0)
 273                 return ret;
 274
 275         ret = gpiochip_add_pin_range(chip, dev_name(pmap->dev), 0, 0,
 276                                      PINS_COUNT);
 277         if (ret < 0) {
 278                 gpiochip_remove(chip);
 279                 return ret;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static int dc_pinctrl_probe(struct platform_device *pdev)
 286 {
 287         struct dc_pinmap *pmap;
 288         struct resource *r;
 289         struct pinctrl_pin_desc *pins;
 290         struct pinctrl_desc *pctl_desc;
 291         char *pin_names;
 292         int name_len = strlen("GP_xx") + 1;
 293         int i, j, ret;
 294
 295         pmap = devm_kzalloc(&pdev->dev, sizeof(*pmap), GFP_KERNEL);
 296         if (!pmap)
 297                 return -ENOMEM;
 298
 299         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 300         pmap->regs = devm_ioremap_resource(&pdev->dev, r);
 301         if (IS_ERR(pmap->regs))
 302                 return PTR_ERR(pmap->regs);
 303
 304         pins = devm_kzalloc(&pdev->dev, sizeof(*pins)*PINS_COUNT, GFP_KERNEL);
 305         if (!pins)
 306                 return -ENOMEM;
 307         pin_names = devm_kzalloc(&pdev->dev, name_len * PINS_COUNT,
 308                                  GFP_KERNEL);
 309         if (!pin_names)
 310                 return -ENOMEM;
 311
 312         for (i = 0; i < PIN_COLLECTIONS; i++) {
 313                 for (j = 0; j < PINS_PER_COLLECTION; j++) {
 314                         int pin_id = i*PINS_PER_COLLECTION + j;
 315                         char *name = &pin_names[pin_id * name_len];
 316
 317                         snprintf(name, name_len, "GP_%c%c", 'A'+i, '0'+j);
 318
 319                         pins[pin_id].number = pin_id;
 320                         pins[pin_id].name = name;
 321                         pmap->pin_names[pin_id] = name;
 322                 }
 323         }
 324
 325         pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL);
 326         if (!pctl_desc)
 327                 return -ENOMEM;
 328
 329         pctl_desc->name = DRIVER_NAME,
 330         pctl_desc->owner = THIS_MODULE,
 331         pctl_desc->pctlops = &dc_pinctrl_ops,
 332         pctl_desc->pmxops = &dc_pmxops,
 333         pctl_desc->npins = PINS_COUNT;
 334         pctl_desc->pins = pins;
 335         pmap->desc = pctl_desc;
 336
 337         pmap->dev = &pdev->dev;
 338
 339         pmap->pctl = pinctrl_register(pctl_desc, &pdev->dev, pmap);
 340         if (IS_ERR(pmap->pctl)) {
 341                 dev_err(&pdev->dev, "pinctrl driver registration failed\n");
 342                 return PTR_ERR(pmap->pctl);
 343         }
 344
 345         ret = dc_gpiochip_add(pmap, pdev->dev.of_node);
 346         if (ret < 0) {
 347                 pinctrl_unregister(pmap->pctl);
 348                 return ret;
 349         }
 350
 351         return 0;
 352 }
 353
 354 static int dc_pinctrl_remove(struct platform_device *pdev)
 355 {
 356         struct dc_pinmap *pmap = platform_get_drvdata(pdev);
 357
 358         pinctrl_unregister(pmap->pctl);
 359         gpiochip_remove(&pmap->chip);
 360
 361         return 0;
 362 }
 363
 364 static const struct of_device_id dc_pinctrl_ids[] = {
 365         { .compatible = "cnxt,cx92755-pinctrl" },
 366         { /* sentinel */ }
 367 };
 368 MODULE_DEVICE_TABLE(of, dc_pinctrl_ids);
 369
 370 static struct platform_driver dc_pinctrl_driver = {
 371         .driver = {
 372                 .name = DRIVER_NAME,
 373                 .of_match_table = dc_pinctrl_ids,
 374         },
 375         .probe = dc_pinctrl_probe,
 376         .remove = dc_pinctrl_remove,
 377 };
 378 module_platform_driver(dc_pinctrl_driver);