drivers/gpio/gpio-tqmx86.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * TQ-Systems TQMx86 PLD GPIO driver
   4  *
   5  * Based on vendor driver by:
   6  *   Vadim V.Vlasov <vvlasov@dev.rtsoft.ru>
   7  */
   8
   9 #include <linux/bitops.h>
  10 #include <linux/errno.h>
  11 #include <linux/gpio/driver.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/pm_runtime.h>
  18 #include <linux/slab.h>
  19
  20 #define TQMX86_NGPIO    8
  21 #define TQMX86_NGPO     4       /* 0-3 - output */
  22 #define TQMX86_NGPI     4       /* 4-7 - input */
  23 #define TQMX86_DIR_INPUT_MASK   0xf0    /* 0-3 - output, 4-7 - input */
  24
  25 #define TQMX86_GPIODD   0       /* GPIO Data Direction Register */
  26 #define TQMX86_GPIOD    1       /* GPIO Data Register */
  27 #define TQMX86_GPIIC    3       /* GPI Interrupt Configuration Register */
  28 #define TQMX86_GPIIS    4       /* GPI Interrupt Status Register */
  29
  30 #define TQMX86_GPII_FALLING     BIT(0)
  31 #define TQMX86_GPII_RISING      BIT(1)
  32 #define TQMX86_GPII_MASK        (BIT(0) | BIT(1))
  33 #define TQMX86_GPII_BITS        2
  34
  35 struct tqmx86_gpio_data {
  36         struct gpio_chip        chip;
  37         struct irq_chip         irq_chip;
  38         void __iomem            *io_base;
  39         int                     irq;
  40         raw_spinlock_t          spinlock;
  41         u8                      irq_type[TQMX86_NGPI];
  42 };
  43
  44 static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg)
  45 {
  46         return ioread8(gd->io_base + reg);
  47 }
  48
  49 static void tqmx86_gpio_write(struct tqmx86_gpio_data *gd, u8 val,
  50                               unsigned int reg)
  51 {
  52         iowrite8(val, gd->io_base + reg);
  53 }
  54
  55 static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset)
  56 {
  57         struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
  58
  59         return !!(tqmx86_gpio_read(gpio, TQMX86_GPIOD) & BIT(offset));
  60 }
  61
  62 static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset,
  63                             int value)
  64 {
  65         struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
  66         unsigned long flags;
  67         u8 val;
  68
  69         raw_spin_lock_irqsave(&gpio->spinlock, flags);
  70         val = tqmx86_gpio_read(gpio, TQMX86_GPIOD);
  71         if (value)
  72                 val |= BIT(offset);
  73         else
  74                 val &= ~BIT(offset);
  75         tqmx86_gpio_write(gpio, val, TQMX86_GPIOD);
  76         raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
  77 }
  78
  79 static int tqmx86_gpio_direction_input(struct gpio_chip *chip,
  80                                        unsigned int offset)
  81 {
  82         /* Direction cannot be changed. Validate is an input. */
  83         if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
  84                 return 0;
  85         else
  86                 return -EINVAL;
  87 }
  88
  89 static int tqmx86_gpio_direction_output(struct gpio_chip *chip,
  90                                         unsigned int offset,
  91                                         int value)
  92 {
  93         /* Direction cannot be changed, validate is an output */
  94         if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
  95                 return -EINVAL;
  96
  97         tqmx86_gpio_set(chip, offset, value);
  98         return 0;
  99 }
 100
 101 static int tqmx86_gpio_get_direction(struct gpio_chip *chip,
 102                                      unsigned int offset)
 103 {
 104         if (TQMX86_DIR_INPUT_MASK & BIT(offset))
 105                 return GPIO_LINE_DIRECTION_IN;
 106
 107         return GPIO_LINE_DIRECTION_OUT;
 108 }
 109
 110 static void tqmx86_gpio_irq_mask(struct irq_data *data)
 111 {
 112         unsigned int offset = (data->hwirq - TQMX86_NGPO);
 113         struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 114                 irq_data_get_irq_chip_data(data));
 115         unsigned long flags;
 116         u8 gpiic, mask;
 117
 118         mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
 119
 120         raw_spin_lock_irqsave(&gpio->spinlock, flags);
 121         gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
 122         gpiic &= ~mask;
 123         tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
 124         raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
 125 }
 126
 127 static void tqmx86_gpio_irq_unmask(struct irq_data *data)
 128 {
 129         unsigned int offset = (data->hwirq - TQMX86_NGPO);
 130         struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 131                 irq_data_get_irq_chip_data(data));
 132         unsigned long flags;
 133         u8 gpiic, mask;
 134
 135         mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
 136
 137         raw_spin_lock_irqsave(&gpio->spinlock, flags);
 138         gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
 139         gpiic &= ~mask;
 140         gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS);
 141         tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
 142         raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
 143 }
 144
 145 static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 146 {
 147         struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 148                 irq_data_get_irq_chip_data(data));
 149         unsigned int offset = (data->hwirq - TQMX86_NGPO);
 150         unsigned int edge_type = type & IRQF_TRIGGER_MASK;
 151         unsigned long flags;
 152         u8 new_type, gpiic;
 153
 154         switch (edge_type) {
 155         case IRQ_TYPE_EDGE_RISING:
 156                 new_type = TQMX86_GPII_RISING;
 157                 break;
 158         case IRQ_TYPE_EDGE_FALLING:
 159                 new_type = TQMX86_GPII_FALLING;
 160                 break;
 161         case IRQ_TYPE_EDGE_BOTH:
 162                 new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
 163                 break;
 164         default:
 165                 return -EINVAL; /* not supported */
 166         }
 167
 168         gpio->irq_type[offset] = new_type;
 169
 170         raw_spin_lock_irqsave(&gpio->spinlock, flags);
 171         gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
 172         gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS));
 173         gpiic |= new_type << (offset * TQMX86_GPII_BITS);
 174         tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
 175         raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
 176
 177         return 0;
 178 }
 179
 180 static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
 181 {
 182         struct gpio_chip *chip = irq_desc_get_handler_data(desc);
 183         struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
 184         struct irq_chip *irq_chip = irq_desc_get_chip(desc);
 185         unsigned long irq_bits;
 186         int i = 0;
 187         u8 irq_status;
 188
 189         chained_irq_enter(irq_chip, desc);
 190
 191         irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
 192         tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
 193
 194         irq_bits = irq_status;
 195         for_each_set_bit(i, &irq_bits, TQMX86_NGPI)
 196                 generic_handle_domain_irq(gpio->chip.irq.domain,
 197                                           i + TQMX86_NGPO);
 198
 199         chained_irq_exit(irq_chip, desc);
 200 }
 201
 202 /* Minimal runtime PM is needed by the IRQ subsystem */
 203 static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev)
 204 {
 205         return 0;
 206 }
 207
 208 static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev)
 209 {
 210         return 0;
 211 }
 212
 213 static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = {
 214         SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend,
 215                            tqmx86_gpio_runtime_resume, NULL)
 216 };
 217
 218 static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip,
 219                                        unsigned long *valid_mask,
 220                                        unsigned int ngpios)
 221 {
 222         /* Only GPIOs 4-7 are valid for interrupts. Clear the others */
 223         clear_bit(0, valid_mask);
 224         clear_bit(1, valid_mask);
 225         clear_bit(2, valid_mask);
 226         clear_bit(3, valid_mask);
 227 }
 228
 229 static int tqmx86_gpio_probe(struct platform_device *pdev)
 230 {
 231         struct device *dev = &pdev->dev;
 232         struct tqmx86_gpio_data *gpio;
 233         struct gpio_chip *chip;
 234         struct gpio_irq_chip *girq;
 235         void __iomem *io_base;
 236         struct resource *res;
 237         int ret, irq;
 238
 239         irq = platform_get_irq_optional(pdev, 0);
 240         if (irq < 0 && irq != -ENXIO)
 241                 return irq;
 242
 243         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 244         if (!res) {
 245                 dev_err(&pdev->dev, "Cannot get I/O\n");
 246                 return -ENODEV;
 247         }
 248
 249         io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res));
 250         if (!io_base)
 251                 return -ENOMEM;
 252
 253         gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
 254         if (!gpio)
 255                 return -ENOMEM;
 256
 257         raw_spin_lock_init(&gpio->spinlock);
 258         gpio->io_base = io_base;
 259
 260         tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD);
 261
 262         platform_set_drvdata(pdev, gpio);
 263
 264         chip = &gpio->chip;
 265         chip->label = "gpio-tqmx86";
 266         chip->owner = THIS_MODULE;
 267         chip->can_sleep = false;
 268         chip->base = -1;
 269         chip->direction_input = tqmx86_gpio_direction_input;
 270         chip->direction_output = tqmx86_gpio_direction_output;
 271         chip->get_direction = tqmx86_gpio_get_direction;
 272         chip->get = tqmx86_gpio_get;
 273         chip->set = tqmx86_gpio_set;
 274         chip->ngpio = TQMX86_NGPIO;
 275         chip->parent = pdev->dev.parent;
 276
 277         pm_runtime_enable(&pdev->dev);
 278
 279         if (irq > 0) {
 280                 struct irq_chip *irq_chip = &gpio->irq_chip;
 281                 u8 irq_status;
 282
 283                 irq_chip->name = chip->label;
 284                 irq_chip->parent_device = &pdev->dev;
 285                 irq_chip->irq_mask = tqmx86_gpio_irq_mask;
 286                 irq_chip->irq_unmask = tqmx86_gpio_irq_unmask;
 287                 irq_chip->irq_set_type = tqmx86_gpio_irq_set_type;
 288
 289                 /* Mask all interrupts */
 290                 tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC);
 291
 292                 /* Clear all pending interrupts */
 293                 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS);
 294                 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
 295
 296                 girq = &chip->irq;
 297                 girq->chip = irq_chip;
 298                 girq->parent_handler = tqmx86_gpio_irq_handler;
 299                 girq->num_parents = 1;
 300                 girq->parents = devm_kcalloc(&pdev->dev, 1,
 301                                              sizeof(*girq->parents),
 302                                              GFP_KERNEL);
 303                 if (!girq->parents) {
 304                         ret = -ENOMEM;
 305                         goto out_pm_dis;
 306                 }
 307                 girq->parents[0] = irq;
 308                 girq->default_type = IRQ_TYPE_NONE;
 309                 girq->handler = handle_simple_irq;
 310                 girq->init_valid_mask = tqmx86_init_irq_valid_mask;
 311         }
 312
 313         ret = devm_gpiochip_add_data(dev, chip, gpio);
 314         if (ret) {
 315                 dev_err(dev, "Could not register GPIO chip\n");
 316                 goto out_pm_dis;
 317         }
 318
 319         dev_info(dev, "GPIO functionality initialized with %d pins\n",
 320                  chip->ngpio);
 321
 322         return 0;
 323
 324 out_pm_dis:
 325         pm_runtime_disable(&pdev->dev);
 326
 327         return ret;
 328 }
 329
 330 static struct platform_driver tqmx86_gpio_driver = {
 331         .driver = {
 332                 .name = "tqmx86-gpio",
 333                 .pm = &tqmx86_gpio_dev_pm_ops,
 334         },
 335         .probe          = tqmx86_gpio_probe,
 336 };
 337
 338 module_platform_driver(tqmx86_gpio_driver);
 339
 340 MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver");
 341 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
 342 MODULE_LICENSE("GPL");
 343 MODULE_ALIAS("platform:tqmx86-gpio");