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/init.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/driver.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/pinctrl/machine.h>
  26 #include <linux/pinctrl/pinconf.h>
  27 #include <linux/pinctrl/pinconf-generic.h>
  28 #include <linux/pinctrl/pinctrl.h>
  29 #include <linux/pinctrl/pinmux.h>
  30 #include "pinctrl-utils.h"
  31
  32 #define DRIVER_NAME     "pinctrl-digicolor"
  33
  34 #define GP_CLIENTSEL(clct)      ((clct)*8 + 0x20)
  35 #define GP_DRIVE0(clct)         (GP_CLIENTSEL(clct) + 2)
  36 #define GP_OUTPUT0(clct)        (GP_CLIENTSEL(clct) + 3)
  37 #define GP_INPUT(clct)          (GP_CLIENTSEL(clct) + 6)
  38
  39 #define PIN_COLLECTIONS         ('R' - 'A' + 1)
  40 #define PINS_PER_COLLECTION     8
  41 #define PINS_COUNT              (PIN_COLLECTIONS * PINS_PER_COLLECTION)
  42
  43 struct dc_pinmap {
  44         void __iomem            *regs;
  45         struct device           *dev;
  46         struct pinctrl_dev      *pctl;
  47
  48         struct pinctrl_desc     *desc;
  49         const char              *pin_names[PINS_COUNT];
  50
  51         struct gpio_chip        chip;
  52         spinlock_t              lock;
  53 };
  54
  55 static int dc_get_groups_count(struct pinctrl_dev *pctldev)
  56 {
  57         return PINS_COUNT;
  58 }
  59
  60 static const char *dc_get_group_name(struct pinctrl_dev *pctldev,
  61                                      unsigned selector)
  62 {
  63         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  64
  65         /* Exactly one group per pin */
  66         return pmap->desc->pins[selector].name;
  67 }
  68
  69 static int dc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
  70                              const unsigned **pins,
  71                              unsigned *num_pins)
  72 {
  73         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  74
  75         *pins = &pmap->desc->pins[selector].number;
  76         *num_pins = 1;
  77
  78         return 0;
  79 }
  80
  81 static const struct pinctrl_ops dc_pinctrl_ops = {
  82         .get_groups_count       = dc_get_groups_count,
  83         .get_group_name         = dc_get_group_name,
  84         .get_group_pins         = dc_get_group_pins,
  85         .dt_node_to_map         = pinconf_generic_dt_node_to_map_pin,
  86         .dt_free_map            = pinctrl_utils_free_map,
  87 };
  88
  89 static const char *const dc_functions[] = {
  90         "gpio",
  91         "client_a",
  92         "client_b",
  93         "client_c",
  94 };
  95
  96 static int dc_get_functions_count(struct pinctrl_dev *pctldev)
  97 {
  98         return ARRAY_SIZE(dc_functions);
  99 }
 100
 101 static const char *dc_get_fname(struct pinctrl_dev *pctldev, unsigned selector)
 102 {
 103         return dc_functions[selector];
 104 }
 105
 106 static int dc_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
 107                          const char * const **groups,
 108                          unsigned * const num_groups)
 109 {
 110         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 111
 112         *groups = pmap->pin_names;
 113         *num_groups = PINS_COUNT;
 114
 115         return 0;
 116 }
 117
 118 static void dc_client_sel(int pin_num, int *reg, int *bit)
 119 {
 120         *bit = (pin_num % PINS_PER_COLLECTION) * 2;
 121         *reg = GP_CLIENTSEL(pin_num/PINS_PER_COLLECTION);
 122
 123         if (*bit >= PINS_PER_COLLECTION) {
 124                 *bit -= PINS_PER_COLLECTION;
 125                 *reg += 1;
 126         }
 127 }
 128
 129 static int dc_set_mux(struct pinctrl_dev *pctldev, unsigned selector,
 130                       unsigned group)
 131 {
 132         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 133         int bit_off, reg_off;
 134         u8 reg;
 135
 136         dc_client_sel(group, &reg_off, &bit_off);
 137
 138         reg = readb_relaxed(pmap->regs + reg_off);
 139         reg &= ~(3 << bit_off);
 140         reg |= (selector << bit_off);
 141         writeb_relaxed(reg, pmap->regs + reg_off);
 142
 143         return 0;
 144 }
 145
 146 static int dc_pmx_request_gpio(struct pinctrl_dev *pcdev,
 147                                struct pinctrl_gpio_range *range,
 148                                unsigned offset)
 149 {
 150         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pcdev);
 151         int bit_off, reg_off;
 152         u8 reg;
 153
 154         dc_client_sel(offset, &reg_off, &bit_off);
 155
 156         reg = readb_relaxed(pmap->regs + reg_off);
 157         if ((reg & (3 << bit_off)) != 0)
 158                 return -EBUSY;
 159
 160         return 0;
 161 }
 162
 163 static const struct pinmux_ops dc_pmxops = {
 164         .get_functions_count    = dc_get_functions_count,
 165         .get_function_name      = dc_get_fname,
 166         .get_function_groups    = dc_get_groups,
 167         .set_mux                = dc_set_mux,
 168         .gpio_request_enable    = dc_pmx_request_gpio,
 169 };
 170
 171 static int dc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 172 {
 173         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 174         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 175         int bit_off = gpio % PINS_PER_COLLECTION;
 176         u8 drive;
 177         unsigned long flags;
 178
 179         spin_lock_irqsave(&pmap->lock, flags);
 180         drive = readb_relaxed(pmap->regs + reg_off);
 181         drive &= ~BIT(bit_off);
 182         writeb_relaxed(drive, pmap->regs + reg_off);
 183         spin_unlock_irqrestore(&pmap->lock, flags);
 184
 185         return 0;
 186 }
 187
 188 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value);
 189
 190 static int dc_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 191                                     int value)
 192 {
 193         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 194         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 195         int bit_off = gpio % PINS_PER_COLLECTION;
 196         u8 drive;
 197         unsigned long flags;
 198
 199         dc_gpio_set(chip, gpio, value);
 200
 201         spin_lock_irqsave(&pmap->lock, flags);
 202         drive = readb_relaxed(pmap->regs + reg_off);
 203         drive |= BIT(bit_off);
 204         writeb_relaxed(drive, pmap->regs + reg_off);
 205         spin_unlock_irqrestore(&pmap->lock, flags);
 206
 207         return 0;
 208 }
 209
 210 static int dc_gpio_get(struct gpio_chip *chip, unsigned gpio)
 211 {
 212         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 213         int reg_off = GP_INPUT(gpio/PINS_PER_COLLECTION);
 214         int bit_off = gpio % PINS_PER_COLLECTION;
 215         u8 input;
 216
 217         input = readb_relaxed(pmap->regs + reg_off);
 218
 219         return !!(input & BIT(bit_off));
 220 }
 221
 222 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 223 {
 224         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 225         int reg_off = GP_OUTPUT0(gpio/PINS_PER_COLLECTION);
 226         int bit_off = gpio % PINS_PER_COLLECTION;
 227         u8 output;
 228         unsigned long flags;
 229
 230         spin_lock_irqsave(&pmap->lock, flags);
 231         output = readb_relaxed(pmap->regs + reg_off);
 232         if (value)
 233                 output |= BIT(bit_off);
 234         else
 235                 output &= ~BIT(bit_off);
 236         writeb_relaxed(output, pmap->regs + reg_off);
 237         spin_unlock_irqrestore(&pmap->lock, flags);
 238 }
 239
 240 static int dc_gpiochip_add(struct dc_pinmap *pmap, struct device_node *np)
 241 {
 242         struct gpio_chip *chip = &pmap->chip;
 243         int ret;
 244
 245         chip->label             = DRIVER_NAME;
 246         chip->parent            = pmap->dev;
 247         chip->request           = gpiochip_generic_request;
 248         chip->free              = gpiochip_generic_free;
 249         chip->direction_input   = dc_gpio_direction_input;
 250         chip->direction_output  = dc_gpio_direction_output;
 251         chip->get               = dc_gpio_get;
 252         chip->set               = dc_gpio_set;
 253         chip->base              = -1;
 254         chip->ngpio             = PINS_COUNT;
 255         chip->of_node           = np;
 256         chip->of_gpio_n_cells   = 2;
 257
 258         spin_lock_init(&pmap->lock);
 259
 260         ret = gpiochip_add_data(chip, pmap);
 261         if (ret < 0)
 262                 return ret;
 263
 264         ret = gpiochip_add_pin_range(chip, dev_name(pmap->dev), 0, 0,
 265                                      PINS_COUNT);
 266         if (ret < 0) {
 267                 gpiochip_remove(chip);
 268                 return ret;
 269         }
 270
 271         return 0;
 272 }
 273
 274 static int dc_pinctrl_probe(struct platform_device *pdev)
 275 {
 276         struct dc_pinmap *pmap;
 277         struct resource *r;
 278         struct pinctrl_pin_desc *pins;
 279         struct pinctrl_desc *pctl_desc;
 280         char *pin_names;
 281         int name_len = strlen("GP_xx") + 1;
 282         int i, j;
 283
 284         pmap = devm_kzalloc(&pdev->dev, sizeof(*pmap), GFP_KERNEL);
 285         if (!pmap)
 286                 return -ENOMEM;
 287
 288         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 289         pmap->regs = devm_ioremap_resource(&pdev->dev, r);
 290         if (IS_ERR(pmap->regs))
 291                 return PTR_ERR(pmap->regs);
 292
 293         pins = devm_kcalloc(&pdev->dev, PINS_COUNT, sizeof(*pins),
 294                             GFP_KERNEL);
 295         if (!pins)
 296                 return -ENOMEM;
 297         pin_names = devm_kcalloc(&pdev->dev, PINS_COUNT, name_len,
 298                                  GFP_KERNEL);
 299         if (!pin_names)
 300                 return -ENOMEM;
 301
 302         for (i = 0; i < PIN_COLLECTIONS; i++) {
 303                 for (j = 0; j < PINS_PER_COLLECTION; j++) {
 304                         int pin_id = i*PINS_PER_COLLECTION + j;
 305                         char *name = &pin_names[pin_id * name_len];
 306
 307                         snprintf(name, name_len, "GP_%c%c", 'A'+i, '0'+j);
 308
 309                         pins[pin_id].number = pin_id;
 310                         pins[pin_id].name = name;
 311                         pmap->pin_names[pin_id] = name;
 312                 }
 313         }
 314
 315         pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL);
 316         if (!pctl_desc)
 317                 return -ENOMEM;
 318
 319         pctl_desc->name = DRIVER_NAME,
 320         pctl_desc->owner = THIS_MODULE,
 321         pctl_desc->pctlops = &dc_pinctrl_ops,
 322         pctl_desc->pmxops = &dc_pmxops,
 323         pctl_desc->npins = PINS_COUNT;
 324         pctl_desc->pins = pins;
 325         pmap->desc = pctl_desc;
 326
 327         pmap->dev = &pdev->dev;
 328
 329         pmap->pctl = devm_pinctrl_register(&pdev->dev, pctl_desc, pmap);
 330         if (IS_ERR(pmap->pctl)) {
 331                 dev_err(&pdev->dev, "pinctrl driver registration failed\n");
 332                 return PTR_ERR(pmap->pctl);
 333         }
 334
 335         return dc_gpiochip_add(pmap, pdev->dev.of_node);
 336 }
 337
 338 static const struct of_device_id dc_pinctrl_ids[] = {
 339         { .compatible = "cnxt,cx92755-pinctrl" },
 340         { /* sentinel */ }
 341 };
 342
 343 static struct platform_driver dc_pinctrl_driver = {
 344         .driver = {
 345                 .name = DRIVER_NAME,
 346                 .of_match_table = dc_pinctrl_ids,
 347                 .suppress_bind_attrs = true,
 348         },
 349         .probe = dc_pinctrl_probe,
 350 };
 351 builtin_platform_driver(dc_pinctrl_driver);