drivers/pinctrl/pinctrl-digicolor.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Driver for Conexant Digicolor General Purpose Pin Mapping
   4  *
   5  * Author: Baruch Siach <baruch@tkos.co.il>
   6  *
   7  * Copyright (C) 2015 Paradox Innovation Ltd.
   8  *
   9  * TODO:
  10  * - GPIO interrupt support
  11  * - Pin pad configuration (pull up/down, strength)
  12  */
  13
  14 #include <linux/init.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18 #include <linux/io.h>
  19 #include <linux/gpio/driver.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/pinctrl/machine.h>
  22 #include <linux/pinctrl/pinconf.h>
  23 #include <linux/pinctrl/pinconf-generic.h>
  24 #include <linux/pinctrl/pinctrl.h>
  25 #include <linux/pinctrl/pinmux.h>
  26 #include "pinctrl-utils.h"
  27
  28 #define DRIVER_NAME     "pinctrl-digicolor"
  29
  30 #define GP_CLIENTSEL(clct)      ((clct)*8 + 0x20)
  31 #define GP_DRIVE0(clct)         (GP_CLIENTSEL(clct) + 2)
  32 #define GP_OUTPUT0(clct)        (GP_CLIENTSEL(clct) + 3)
  33 #define GP_INPUT(clct)          (GP_CLIENTSEL(clct) + 6)
  34
  35 #define PIN_COLLECTIONS         ('R' - 'A' + 1)
  36 #define PINS_PER_COLLECTION     8
  37 #define PINS_COUNT              (PIN_COLLECTIONS * PINS_PER_COLLECTION)
  38
  39 struct dc_pinmap {
  40         void __iomem            *regs;
  41         struct device           *dev;
  42         struct pinctrl_dev      *pctl;
  43
  44         struct pinctrl_desc     *desc;
  45         const char              *pin_names[PINS_COUNT];
  46
  47         struct gpio_chip        chip;
  48         spinlock_t              lock;
  49 };
  50
  51 static int dc_get_groups_count(struct pinctrl_dev *pctldev)
  52 {
  53         return PINS_COUNT;
  54 }
  55
  56 static const char *dc_get_group_name(struct pinctrl_dev *pctldev,
  57                                      unsigned selector)
  58 {
  59         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  60
  61         /* Exactly one group per pin */
  62         return pmap->desc->pins[selector].name;
  63 }
  64
  65 static int dc_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
  66                              const unsigned **pins,
  67                              unsigned *num_pins)
  68 {
  69         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
  70
  71         *pins = &pmap->desc->pins[selector].number;
  72         *num_pins = 1;
  73
  74         return 0;
  75 }
  76
  77 static const struct pinctrl_ops dc_pinctrl_ops = {
  78         .get_groups_count       = dc_get_groups_count,
  79         .get_group_name         = dc_get_group_name,
  80         .get_group_pins         = dc_get_group_pins,
  81         .dt_node_to_map         = pinconf_generic_dt_node_to_map_pin,
  82         .dt_free_map            = pinctrl_utils_free_map,
  83 };
  84
  85 static const char *const dc_functions[] = {
  86         "gpio",
  87         "client_a",
  88         "client_b",
  89         "client_c",
  90 };
  91
  92 static int dc_get_functions_count(struct pinctrl_dev *pctldev)
  93 {
  94         return ARRAY_SIZE(dc_functions);
  95 }
  96
  97 static const char *dc_get_fname(struct pinctrl_dev *pctldev, unsigned selector)
  98 {
  99         return dc_functions[selector];
 100 }
 101
 102 static int dc_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
 103                          const char * const **groups,
 104                          unsigned * const num_groups)
 105 {
 106         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 107
 108         *groups = pmap->pin_names;
 109         *num_groups = PINS_COUNT;
 110
 111         return 0;
 112 }
 113
 114 static void dc_client_sel(int pin_num, int *reg, int *bit)
 115 {
 116         *bit = (pin_num % PINS_PER_COLLECTION) * 2;
 117         *reg = GP_CLIENTSEL(pin_num/PINS_PER_COLLECTION);
 118
 119         if (*bit >= PINS_PER_COLLECTION) {
 120                 *bit -= PINS_PER_COLLECTION;
 121                 *reg += 1;
 122         }
 123 }
 124
 125 static int dc_set_mux(struct pinctrl_dev *pctldev, unsigned selector,
 126                       unsigned group)
 127 {
 128         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pctldev);
 129         int bit_off, reg_off;
 130         u8 reg;
 131
 132         dc_client_sel(group, &reg_off, &bit_off);
 133
 134         reg = readb_relaxed(pmap->regs + reg_off);
 135         reg &= ~(3 << bit_off);
 136         reg |= (selector << bit_off);
 137         writeb_relaxed(reg, pmap->regs + reg_off);
 138
 139         return 0;
 140 }
 141
 142 static int dc_pmx_request_gpio(struct pinctrl_dev *pcdev,
 143                                struct pinctrl_gpio_range *range,
 144                                unsigned offset)
 145 {
 146         struct dc_pinmap *pmap = pinctrl_dev_get_drvdata(pcdev);
 147         int bit_off, reg_off;
 148         u8 reg;
 149
 150         dc_client_sel(offset, &reg_off, &bit_off);
 151
 152         reg = readb_relaxed(pmap->regs + reg_off);
 153         if ((reg & (3 << bit_off)) != 0)
 154                 return -EBUSY;
 155
 156         return 0;
 157 }
 158
 159 static const struct pinmux_ops dc_pmxops = {
 160         .get_functions_count    = dc_get_functions_count,
 161         .get_function_name      = dc_get_fname,
 162         .get_function_groups    = dc_get_groups,
 163         .set_mux                = dc_set_mux,
 164         .gpio_request_enable    = dc_pmx_request_gpio,
 165 };
 166
 167 static int dc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 168 {
 169         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 170         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 171         int bit_off = gpio % PINS_PER_COLLECTION;
 172         u8 drive;
 173         unsigned long flags;
 174
 175         spin_lock_irqsave(&pmap->lock, flags);
 176         drive = readb_relaxed(pmap->regs + reg_off);
 177         drive &= ~BIT(bit_off);
 178         writeb_relaxed(drive, pmap->regs + reg_off);
 179         spin_unlock_irqrestore(&pmap->lock, flags);
 180
 181         return 0;
 182 }
 183
 184 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value);
 185
 186 static int dc_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 187                                     int value)
 188 {
 189         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 190         int reg_off = GP_DRIVE0(gpio/PINS_PER_COLLECTION);
 191         int bit_off = gpio % PINS_PER_COLLECTION;
 192         u8 drive;
 193         unsigned long flags;
 194
 195         dc_gpio_set(chip, gpio, value);
 196
 197         spin_lock_irqsave(&pmap->lock, flags);
 198         drive = readb_relaxed(pmap->regs + reg_off);
 199         drive |= BIT(bit_off);
 200         writeb_relaxed(drive, pmap->regs + reg_off);
 201         spin_unlock_irqrestore(&pmap->lock, flags);
 202
 203         return 0;
 204 }
 205
 206 static int dc_gpio_get(struct gpio_chip *chip, unsigned gpio)
 207 {
 208         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 209         int reg_off = GP_INPUT(gpio/PINS_PER_COLLECTION);
 210         int bit_off = gpio % PINS_PER_COLLECTION;
 211         u8 input;
 212
 213         input = readb_relaxed(pmap->regs + reg_off);
 214
 215         return !!(input & BIT(bit_off));
 216 }
 217
 218 static void dc_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 219 {
 220         struct dc_pinmap *pmap = gpiochip_get_data(chip);
 221         int reg_off = GP_OUTPUT0(gpio/PINS_PER_COLLECTION);
 222         int bit_off = gpio % PINS_PER_COLLECTION;
 223         u8 output;
 224         unsigned long flags;
 225
 226         spin_lock_irqsave(&pmap->lock, flags);
 227         output = readb_relaxed(pmap->regs + reg_off);
 228         if (value)
 229                 output |= BIT(bit_off);
 230         else
 231                 output &= ~BIT(bit_off);
 232         writeb_relaxed(output, pmap->regs + reg_off);
 233         spin_unlock_irqrestore(&pmap->lock, flags);
 234 }
 235
 236 static int dc_gpiochip_add(struct dc_pinmap *pmap, struct device_node *np)
 237 {
 238         struct gpio_chip *chip = &pmap->chip;
 239         int ret;
 240
 241         chip->label             = DRIVER_NAME;
 242         chip->parent            = pmap->dev;
 243         chip->request           = gpiochip_generic_request;
 244         chip->free              = gpiochip_generic_free;
 245         chip->direction_input   = dc_gpio_direction_input;
 246         chip->direction_output  = dc_gpio_direction_output;
 247         chip->get               = dc_gpio_get;
 248         chip->set               = dc_gpio_set;
 249         chip->base              = -1;
 250         chip->ngpio             = PINS_COUNT;
 251         chip->of_node           = np;
 252         chip->of_gpio_n_cells   = 2;
 253
 254         spin_lock_init(&pmap->lock);
 255
 256         ret = gpiochip_add_data(chip, pmap);
 257         if (ret < 0)
 258                 return ret;
 259
 260         ret = gpiochip_add_pin_range(chip, dev_name(pmap->dev), 0, 0,
 261                                      PINS_COUNT);
 262         if (ret < 0) {
 263                 gpiochip_remove(chip);
 264                 return ret;
 265         }
 266
 267         return 0;
 268 }
 269
 270 static int dc_pinctrl_probe(struct platform_device *pdev)
 271 {
 272         struct dc_pinmap *pmap;
 273         struct pinctrl_pin_desc *pins;
 274         struct pinctrl_desc *pctl_desc;
 275         char *pin_names;
 276         int name_len = strlen("GP_xx") + 1;
 277         int i, j;
 278
 279         pmap = devm_kzalloc(&pdev->dev, sizeof(*pmap), GFP_KERNEL);
 280         if (!pmap)
 281                 return -ENOMEM;
 282
 283         pmap->regs = devm_platform_ioremap_resource(pdev, 0);
 284         if (IS_ERR(pmap->regs))
 285                 return PTR_ERR(pmap->regs);
 286
 287         pins = devm_kcalloc(&pdev->dev, PINS_COUNT, sizeof(*pins),
 288                             GFP_KERNEL);
 289         if (!pins)
 290                 return -ENOMEM;
 291         pin_names = devm_kcalloc(&pdev->dev, PINS_COUNT, name_len,
 292                                  GFP_KERNEL);
 293         if (!pin_names)
 294                 return -ENOMEM;
 295
 296         for (i = 0; i < PIN_COLLECTIONS; i++) {
 297                 for (j = 0; j < PINS_PER_COLLECTION; j++) {
 298                         int pin_id = i*PINS_PER_COLLECTION + j;
 299                         char *name = &pin_names[pin_id * name_len];
 300
 301                         snprintf(name, name_len, "GP_%c%c", 'A'+i, '0'+j);
 302
 303                         pins[pin_id].number = pin_id;
 304                         pins[pin_id].name = name;
 305                         pmap->pin_names[pin_id] = name;
 306                 }
 307         }
 308
 309         pctl_desc = devm_kzalloc(&pdev->dev, sizeof(*pctl_desc), GFP_KERNEL);
 310         if (!pctl_desc)
 311                 return -ENOMEM;
 312
 313         pctl_desc->name = DRIVER_NAME,
 314         pctl_desc->owner = THIS_MODULE,
 315         pctl_desc->pctlops = &dc_pinctrl_ops,
 316         pctl_desc->pmxops = &dc_pmxops,
 317         pctl_desc->npins = PINS_COUNT;
 318         pctl_desc->pins = pins;
 319         pmap->desc = pctl_desc;
 320
 321         pmap->dev = &pdev->dev;
 322
 323         pmap->pctl = devm_pinctrl_register(&pdev->dev, pctl_desc, pmap);
 324         if (IS_ERR(pmap->pctl)) {
 325                 dev_err(&pdev->dev, "pinctrl driver registration failed\n");
 326                 return PTR_ERR(pmap->pctl);
 327         }
 328
 329         return dc_gpiochip_add(pmap, pdev->dev.of_node);
 330 }
 331
 332 static const struct of_device_id dc_pinctrl_ids[] = {
 333         { .compatible = "cnxt,cx92755-pinctrl" },
 334         { /* sentinel */ }
 335 };
 336
 337 static struct platform_driver dc_pinctrl_driver = {
 338         .driver = {
 339                 .name = DRIVER_NAME,
 340                 .of_match_table = dc_pinctrl_ids,
 341                 .suppress_bind_attrs = true,
 342         },
 343         .probe = dc_pinctrl_probe,
 344 };
 345 builtin_platform_driver(dc_pinctrl_driver);