drivers/gpio/gpio-tc3589x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) ST-Ericsson SA 2010
   4  *
   5  * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
   6  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/gpio/driver.h>
  13 #include <linux/of.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/mfd/tc3589x.h>
  16 #include <linux/bitops.h>
  17
  18 /*
  19  * These registers are modified under the irq bus lock and cached to avoid
  20  * unnecessary writes in bus_sync_unlock.
  21  */
  22 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
  23
  24 #define CACHE_NR_REGS   4
  25 #define CACHE_NR_BANKS  3
  26
  27 struct tc3589x_gpio {
  28         struct gpio_chip chip;
  29         struct tc3589x *tc3589x;
  30         struct device *dev;
  31         struct mutex irq_lock;
  32         /* Caches of interrupt control registers for bus_lock */
  33         u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
  34         u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
  35 };
  36
  37 static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned int offset)
  38 {
  39         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
  40         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  41         u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
  42         u8 mask = BIT(offset % 8);
  43         int ret;
  44
  45         ret = tc3589x_reg_read(tc3589x, reg);
  46         if (ret < 0)
  47                 return ret;
  48
  49         return !!(ret & mask);
  50 }
  51
  52 static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned int offset, int val)
  53 {
  54         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
  55         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  56         u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
  57         unsigned int pos = offset % 8;
  58         u8 data[] = {val ? BIT(pos) : 0, BIT(pos)};
  59
  60         tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
  61 }
  62
  63 static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
  64                                          unsigned int offset, int val)
  65 {
  66         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
  67         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  68         u8 reg = TC3589x_GPIODIR0 + offset / 8;
  69         unsigned int pos = offset % 8;
  70
  71         tc3589x_gpio_set(chip, offset, val);
  72
  73         return tc3589x_set_bits(tc3589x, reg, BIT(pos), BIT(pos));
  74 }
  75
  76 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
  77                                         unsigned int offset)
  78 {
  79         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
  80         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  81         u8 reg = TC3589x_GPIODIR0 + offset / 8;
  82         unsigned int pos = offset % 8;
  83
  84         return tc3589x_set_bits(tc3589x, reg, BIT(pos), 0);
  85 }
  86
  87 static int tc3589x_gpio_get_direction(struct gpio_chip *chip,
  88                                       unsigned int offset)
  89 {
  90         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
  91         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  92         u8 reg = TC3589x_GPIODIR0 + offset / 8;
  93         unsigned int pos = offset % 8;
  94         int ret;
  95
  96         ret = tc3589x_reg_read(tc3589x, reg);
  97         if (ret < 0)
  98                 return ret;
  99
 100         if (ret & BIT(pos))
 101                 return GPIO_LINE_DIRECTION_OUT;
 102
 103         return GPIO_LINE_DIRECTION_IN;
 104 }
 105
 106 static int tc3589x_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 107                                    unsigned long config)
 108 {
 109         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(chip);
 110         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
 111         /*
 112          * These registers are alterated at each second address
 113          * ODM bit 0 = drive to GND or Hi-Z (open drain)
 114          * ODM bit 1 = drive to VDD or Hi-Z (open source)
 115          */
 116         u8 odmreg = TC3589x_GPIOODM0 + (offset / 8) * 2;
 117         u8 odereg = TC3589x_GPIOODE0 + (offset / 8) * 2;
 118         unsigned int pos = offset % 8;
 119         int ret;
 120
 121         switch (pinconf_to_config_param(config)) {
 122         case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 123                 /* Set open drain mode */
 124                 ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), 0);
 125                 if (ret)
 126                         return ret;
 127                 /* Enable open drain/source mode */
 128                 return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
 129         case PIN_CONFIG_DRIVE_OPEN_SOURCE:
 130                 /* Set open source mode */
 131                 ret = tc3589x_set_bits(tc3589x, odmreg, BIT(pos), BIT(pos));
 132                 if (ret)
 133                         return ret;
 134                 /* Enable open drain/source mode */
 135                 return tc3589x_set_bits(tc3589x, odereg, BIT(pos), BIT(pos));
 136         case PIN_CONFIG_DRIVE_PUSH_PULL:
 137                 /* Disable open drain/source mode */
 138                 return tc3589x_set_bits(tc3589x, odereg, BIT(pos), 0);
 139         default:
 140                 break;
 141         }
 142         return -ENOTSUPP;
 143 }
 144
 145 static const struct gpio_chip template_chip = {
 146         .label                  = "tc3589x",
 147         .owner                  = THIS_MODULE,
 148         .get                    = tc3589x_gpio_get,
 149         .set                    = tc3589x_gpio_set,
 150         .direction_output       = tc3589x_gpio_direction_output,
 151         .direction_input        = tc3589x_gpio_direction_input,
 152         .get_direction          = tc3589x_gpio_get_direction,
 153         .set_config             = tc3589x_gpio_set_config,
 154         .can_sleep              = true,
 155 };
 156
 157 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 158 {
 159         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 160         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
 161         int offset = d->hwirq;
 162         int regoffset = offset / 8;
 163         int mask = BIT(offset % 8);
 164
 165         if (type == IRQ_TYPE_EDGE_BOTH) {
 166                 tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
 167                 return 0;
 168         }
 169
 170         tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
 171
 172         if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
 173                 tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
 174         else
 175                 tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
 176
 177         if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
 178                 tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
 179         else
 180                 tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
 181
 182         return 0;
 183 }
 184
 185 static void tc3589x_gpio_irq_lock(struct irq_data *d)
 186 {
 187         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 188         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
 189
 190         mutex_lock(&tc3589x_gpio->irq_lock);
 191 }
 192
 193 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
 194 {
 195         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 196         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
 197         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
 198         static const u8 regmap[] = {
 199                 [REG_IBE]       = TC3589x_GPIOIBE0,
 200                 [REG_IEV]       = TC3589x_GPIOIEV0,
 201                 [REG_IS]        = TC3589x_GPIOIS0,
 202                 [REG_IE]        = TC3589x_GPIOIE0,
 203         };
 204         int i, j;
 205
 206         for (i = 0; i < CACHE_NR_REGS; i++) {
 207                 for (j = 0; j < CACHE_NR_BANKS; j++) {
 208                         u8 old = tc3589x_gpio->oldregs[i][j];
 209                         u8 new = tc3589x_gpio->regs[i][j];
 210
 211                         if (new == old)
 212                                 continue;
 213
 214                         tc3589x_gpio->oldregs[i][j] = new;
 215                         tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
 216                 }
 217         }
 218
 219         mutex_unlock(&tc3589x_gpio->irq_lock);
 220 }
 221
 222 static void tc3589x_gpio_irq_mask(struct irq_data *d)
 223 {
 224         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 225         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
 226         int offset = d->hwirq;
 227         int regoffset = offset / 8;
 228         int mask = BIT(offset % 8);
 229
 230         tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
 231 }
 232
 233 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
 234 {
 235         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 236         struct tc3589x_gpio *tc3589x_gpio = gpiochip_get_data(gc);
 237         int offset = d->hwirq;
 238         int regoffset = offset / 8;
 239         int mask = BIT(offset % 8);
 240
 241         tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
 242 }
 243
 244 static struct irq_chip tc3589x_gpio_irq_chip = {
 245         .name                   = "tc3589x-gpio",
 246         .irq_bus_lock           = tc3589x_gpio_irq_lock,
 247         .irq_bus_sync_unlock    = tc3589x_gpio_irq_sync_unlock,
 248         .irq_mask               = tc3589x_gpio_irq_mask,
 249         .irq_unmask             = tc3589x_gpio_irq_unmask,
 250         .irq_set_type           = tc3589x_gpio_irq_set_type,
 251 };
 252
 253 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
 254 {
 255         struct tc3589x_gpio *tc3589x_gpio = dev;
 256         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
 257         u8 status[CACHE_NR_BANKS];
 258         int ret;
 259         int i;
 260
 261         ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
 262                                  ARRAY_SIZE(status), status);
 263         if (ret < 0)
 264                 return IRQ_NONE;
 265
 266         for (i = 0; i < ARRAY_SIZE(status); i++) {
 267                 unsigned int stat = status[i];
 268                 if (!stat)
 269                         continue;
 270
 271                 while (stat) {
 272                         int bit = __ffs(stat);
 273                         int line = i * 8 + bit;
 274                         int irq = irq_find_mapping(tc3589x_gpio->chip.irq.domain,
 275                                                    line);
 276
 277                         handle_nested_irq(irq);
 278                         stat &= ~(1 << bit);
 279                 }
 280
 281                 tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
 282         }
 283
 284         return IRQ_HANDLED;
 285 }
 286
 287 static int tc3589x_gpio_probe(struct platform_device *pdev)
 288 {
 289         struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
 290         struct device_node *np = pdev->dev.of_node;
 291         struct tc3589x_gpio *tc3589x_gpio;
 292         int ret;
 293         int irq;
 294
 295         if (!np) {
 296                 dev_err(&pdev->dev, "No Device Tree node found\n");
 297                 return -EINVAL;
 298         }
 299
 300         irq = platform_get_irq(pdev, 0);
 301         if (irq < 0)
 302                 return irq;
 303
 304         tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
 305                                     GFP_KERNEL);
 306         if (!tc3589x_gpio)
 307                 return -ENOMEM;
 308
 309         mutex_init(&tc3589x_gpio->irq_lock);
 310
 311         tc3589x_gpio->dev = &pdev->dev;
 312         tc3589x_gpio->tc3589x = tc3589x;
 313
 314         tc3589x_gpio->chip = template_chip;
 315         tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
 316         tc3589x_gpio->chip.parent = &pdev->dev;
 317         tc3589x_gpio->chip.base = -1;
 318         tc3589x_gpio->chip.of_node = np;
 319
 320         /* Bring the GPIO module out of reset */
 321         ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
 322                                TC3589x_RSTCTRL_GPIRST, 0);
 323         if (ret < 0)
 324                 return ret;
 325
 326         ret = devm_request_threaded_irq(&pdev->dev,
 327                                         irq, NULL, tc3589x_gpio_irq,
 328                                         IRQF_ONESHOT, "tc3589x-gpio",
 329                                         tc3589x_gpio);
 330         if (ret) {
 331                 dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
 332                 return ret;
 333         }
 334
 335         ret = devm_gpiochip_add_data(&pdev->dev, &tc3589x_gpio->chip,
 336                                      tc3589x_gpio);
 337         if (ret) {
 338                 dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
 339                 return ret;
 340         }
 341
 342         ret =  gpiochip_irqchip_add_nested(&tc3589x_gpio->chip,
 343                                            &tc3589x_gpio_irq_chip,
 344                                            0,
 345                                            handle_simple_irq,
 346                                            IRQ_TYPE_NONE);
 347         if (ret) {
 348                 dev_err(&pdev->dev,
 349                         "could not connect irqchip to gpiochip\n");
 350                 return ret;
 351         }
 352
 353         gpiochip_set_nested_irqchip(&tc3589x_gpio->chip,
 354                                     &tc3589x_gpio_irq_chip,
 355                                     irq);
 356
 357         platform_set_drvdata(pdev, tc3589x_gpio);
 358
 359         return 0;
 360 }
 361
 362 static struct platform_driver tc3589x_gpio_driver = {
 363         .driver.name    = "tc3589x-gpio",
 364         .probe          = tc3589x_gpio_probe,
 365 };
 366
 367 static int __init tc3589x_gpio_init(void)
 368 {
 369         return platform_driver_register(&tc3589x_gpio_driver);
 370 }
 371 subsys_initcall(tc3589x_gpio_init);