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.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_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_direction_input(struct gpio_chip *chip, unsigned gpio)
 173 {
 174         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 175         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 176         int bit_off = gpio % PINS_PER_COLLECTION;
 177         u8 drive;
 178         unsigned long flags;
 179
 180         spin_lock_irqsave(&pmap->lock, flags);
 181         drive = readb_relaxed(pmap->regs + reg_off);
 182         drive &= ~BIT(bit_off);
 183         writeb_relaxed(drive, pmap->regs + reg_off);
 184         spin_unlock_irqrestore(&pmap->lock, flags);
 185
 186         return 0;
 187 }
 188
 189 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value);
 190
 191 static int dc_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 192                                     int value)
 193 {
 194         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 195         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 196         int bit_off = gpio % PINS_PER_COLLECTION;
 197         u8 drive;
 198         unsigned long flags;
 199
 200         dc_gpio_set(chip, gpio, value);
 201
 202         spin_lock_irqsave(&pmap->lock, flags);
 203         drive = readb_relaxed(pmap->regs + reg_off);
 204         drive |= BIT(bit_off);
 205         writeb_relaxed(drive, pmap->regs + reg_off);
 206         spin_unlock_irqrestore(&pmap->lock, flags);
 207
 208         return 0;
 209 }
 210
 211 static int dc_gpio_get(struct gpio_chip *chip, unsigned gpio)
 212 {
 213         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 214         int reg_off = GP_INPUT(gpio/PINS_PER_COLLECTION);
 215         int bit_off = gpio % PINS_PER_COLLECTION;
 216         u8 input;
 217
 218         input = readb_relaxed(pmap->regs + reg_off);
 219
 220         return !!(input & BIT(bit_off));
 221 }
 222
 223 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 224 {
 225         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 226         int reg_off = GP_OUTPUT0(gpio/PINS_PER_COLLECTION);
 227         int bit_off = gpio % PINS_PER_COLLECTION;
 228         u8 output;
 229         unsigned long flags;
 230
 231         spin_lock_irqsave(&pmap->lock, flags);
 232         output = readb_relaxed(pmap->regs + reg_off);
 233         if (value)
 234                 output |= BIT(bit_off);
 235         else
 236                 output &= ~BIT(bit_off);
 237         writeb_relaxed(output, pmap->regs + reg_off);
 238         spin_unlock_irqrestore(&pmap->lock, flags);
 239 }
 240
 241 static int dc_gpiochip_add(struct dc_pinmap *pmap, struct device_node *np)
 242 {
 243         struct gpio_chip *chip = &pmap->chip;
 244         int ret;
 245
 246         chip->label             = DRIVER_NAME;
 247         chip->parent            = pmap->dev;
 248         chip->request           = gpiochip_generic_request;
 249         chip->free              = gpiochip_generic_free;
 250         chip->direction_input   = dc_gpio_direction_input;
 251         chip->direction_output  = dc_gpio_direction_output;
 252         chip->get               = dc_gpio_get;
 253         chip->set               = dc_gpio_set;
 254         chip->base              = -1;
 255         chip->ngpio             = PINS_COUNT;
 256         chip->of_node           = np;
 257         chip->of_gpio_n_cells   = 2;
 258
 259         spin_lock_init(&pmap->lock);
 260
 261         ret = gpiochip_add_data(chip, pmap);
 262         if (ret < 0)
 263                 return ret;
 264
 265         ret = gpiochip_add_pin_range(chip, dev_name(pmap->dev), 0, 0,
 266                                      PINS_COUNT);
 267         if (ret < 0) {
 268                 gpiochip_remove(chip);
 269                 return ret;
 270         }
 271
 272         return 0;
 273 }
 274
 275 static int dc_pinctrl_probe(struct platform_device *pdev)
 276 {
 277         struct dc_pinmap *pmap;
 278         struct resource *r;
 279         struct pinctrl_pin_desc *pins;
 280         struct pinctrl_desc *pctl_desc;
 281         char *pin_names;
 282         int name_len = strlen("GP_xx") + 1;
 283         int i, j;
 284
 285         pmap = devm_kzalloc(&pdev->dev, sizeof(*pmap), GFP_KERNEL);
 286         if (!pmap)
 287                 return -ENOMEM;
 288
 289         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 290         pmap->regs = devm_ioremap_resource(&pdev->dev, r);
 291         if (IS_ERR(pmap->regs))
 292                 return PTR_ERR(pmap->regs);
 293
 294         pins = devm_kzalloc(&pdev->dev, sizeof(*pins)*PINS_COUNT, GFP_KERNEL);
 295         if (!pins)
 296                 return -ENOMEM;
 297         pin_names = devm_kzalloc(&pdev->dev, name_len * PINS_COUNT,
 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);