drivers/gpio/gpio-zx.c

   1 /*
   2  * Copyright (C) 2015 Linaro Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <linux/bitops.h>
   9 #include <linux/device.h>
  10 #include <linux/errno.h>
  11 #include <linux/gpio/driver.h>
  12 #include <linux/irqchip/chained_irq.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/pinctrl/consumer.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/pm.h>
  18 #include <linux/slab.h>
  19 #include <linux/spinlock.h>
  20
  21 #define ZX_GPIO_DIR     0x00
  22 #define ZX_GPIO_IVE     0x04
  23 #define ZX_GPIO_IV      0x08
  24 #define ZX_GPIO_IEP     0x0C
  25 #define ZX_GPIO_IEN     0x10
  26 #define ZX_GPIO_DI      0x14
  27 #define ZX_GPIO_DO1     0x18
  28 #define ZX_GPIO_DO0     0x1C
  29 #define ZX_GPIO_DO      0x20
  30
  31 #define ZX_GPIO_IM      0x28
  32 #define ZX_GPIO_IE      0x2C
  33
  34 #define ZX_GPIO_MIS     0x30
  35 #define ZX_GPIO_IC      0x34
  36
  37 #define ZX_GPIO_NR      16
  38
  39 struct zx_gpio {
  40         spinlock_t              lock;
  41
  42         void __iomem            *base;
  43         struct gpio_chip        gc;
  44         bool                    uses_pinctrl;
  45 };
  46
  47 static inline struct zx_gpio *to_zx(struct gpio_chip *gc)
  48 {
  49         return container_of(gc, struct zx_gpio, gc);
  50 }
  51
  52 static int zx_gpio_request(struct gpio_chip *gc, unsigned offset)
  53 {
  54         struct zx_gpio *chip = to_zx(gc);
  55         int gpio = gc->base + offset;
  56
  57         if (chip->uses_pinctrl)
  58                 return pinctrl_request_gpio(gpio);
  59         return 0;
  60 }
  61
  62 static void zx_gpio_free(struct gpio_chip *gc, unsigned offset)
  63 {
  64         struct zx_gpio *chip = to_zx(gc);
  65         int gpio = gc->base + offset;
  66
  67         if (chip->uses_pinctrl)
  68                 pinctrl_free_gpio(gpio);
  69 }
  70
  71 static int zx_direction_input(struct gpio_chip *gc, unsigned offset)
  72 {
  73         struct zx_gpio *chip = to_zx(gc);
  74         unsigned long flags;
  75         u16 gpiodir;
  76
  77         if (offset >= gc->ngpio)
  78                 return -EINVAL;
  79
  80         spin_lock_irqsave(&chip->lock, flags);
  81         gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
  82         gpiodir &= ~BIT(offset);
  83         writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
  84         spin_unlock_irqrestore(&chip->lock, flags);
  85
  86         return 0;
  87 }
  88
  89 static int zx_direction_output(struct gpio_chip *gc, unsigned offset,
  90                 int value)
  91 {
  92         struct zx_gpio *chip = to_zx(gc);
  93         unsigned long flags;
  94         u16 gpiodir;
  95
  96         if (offset >= gc->ngpio)
  97                 return -EINVAL;
  98
  99         spin_lock_irqsave(&chip->lock, flags);
 100         gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
 101         gpiodir |= BIT(offset);
 102         writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
 103
 104         if (value)
 105                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
 106         else
 107                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
 108         spin_unlock_irqrestore(&chip->lock, flags);
 109
 110         return 0;
 111 }
 112
 113 static int zx_get_value(struct gpio_chip *gc, unsigned offset)
 114 {
 115         struct zx_gpio *chip = to_zx(gc);
 116
 117         return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset));
 118 }
 119
 120 static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value)
 121 {
 122         struct zx_gpio *chip = to_zx(gc);
 123
 124         if (value)
 125                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
 126         else
 127                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
 128 }
 129
 130 static int zx_irq_type(struct irq_data *d, unsigned trigger)
 131 {
 132         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 133         struct zx_gpio *chip = to_zx(gc);
 134         int offset = irqd_to_hwirq(d);
 135         unsigned long flags;
 136         u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev;
 137         u16 bit = BIT(offset);
 138
 139         if (offset < 0 || offset >= ZX_GPIO_NR)
 140                 return -EINVAL;
 141
 142         spin_lock_irqsave(&chip->lock, flags);
 143
 144         gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV);
 145         gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE);
 146         gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP);
 147         gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN);
 148
 149         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 150                 gpiois |= bit;
 151                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 152                         gpioiev |= bit;
 153                 else
 154                         gpioiev &= ~bit;
 155         } else
 156                 gpiois &= ~bit;
 157
 158         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 159                 gpioi_epos |= bit;
 160                 gpioi_eneg |= bit;
 161         } else {
 162                 if (trigger & IRQ_TYPE_EDGE_RISING) {
 163                         gpioi_epos |= bit;
 164                         gpioi_eneg &= ~bit;
 165                 } else if (trigger & IRQ_TYPE_EDGE_FALLING) {
 166                         gpioi_eneg |= bit;
 167                         gpioi_epos &= ~bit;
 168                 }
 169         }
 170
 171         writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE);
 172         writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP);
 173         writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN);
 174         writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV);
 175         spin_unlock_irqrestore(&chip->lock, flags);
 176
 177         return 0;
 178 }
 179
 180 static void zx_irq_handler(struct irq_desc *desc)
 181 {
 182         unsigned long pending;
 183         int offset;
 184         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 185         struct zx_gpio *chip = to_zx(gc);
 186         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 187
 188         chained_irq_enter(irqchip, desc);
 189
 190         pending = readw_relaxed(chip->base + ZX_GPIO_MIS);
 191         writew_relaxed(pending, chip->base + ZX_GPIO_IC);
 192         if (pending) {
 193                 for_each_set_bit(offset, &pending, ZX_GPIO_NR)
 194                         generic_handle_irq(irq_find_mapping(gc->irqdomain,
 195                                                             offset));
 196         }
 197
 198         chained_irq_exit(irqchip, desc);
 199 }
 200
 201 static void zx_irq_mask(struct irq_data *d)
 202 {
 203         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 204         struct zx_gpio *chip = to_zx(gc);
 205         u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
 206         u16 gpioie;
 207
 208         spin_lock(&chip->lock);
 209         gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask;
 210         writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
 211         gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask;
 212         writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
 213         spin_unlock(&chip->lock);
 214 }
 215
 216 static void zx_irq_unmask(struct irq_data *d)
 217 {
 218         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 219         struct zx_gpio *chip = to_zx(gc);
 220         u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
 221         u16 gpioie;
 222
 223         spin_lock(&chip->lock);
 224         gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask;
 225         writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
 226         gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask;
 227         writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
 228         spin_unlock(&chip->lock);
 229 }
 230
 231 static struct irq_chip zx_irqchip = {
 232         .name           = "zx-gpio",
 233         .irq_mask       = zx_irq_mask,
 234         .irq_unmask     = zx_irq_unmask,
 235         .irq_set_type   = zx_irq_type,
 236 };
 237
 238 static int zx_gpio_probe(struct platform_device *pdev)
 239 {
 240         struct device *dev = &pdev->dev;
 241         struct zx_gpio *chip;
 242         struct resource *res;
 243         int irq, id, ret;
 244
 245         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 246         if (!chip)
 247                 return -ENOMEM;
 248
 249         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 250         chip->base = devm_ioremap_resource(dev, res);
 251         if (IS_ERR(chip->base))
 252                 return PTR_ERR(chip->base);
 253
 254         spin_lock_init(&chip->lock);
 255         if (of_property_read_bool(dev->of_node, "gpio-ranges"))
 256                 chip->uses_pinctrl = true;
 257
 258         id = of_alias_get_id(dev->of_node, "gpio");
 259         chip->gc.request = zx_gpio_request;
 260         chip->gc.free = zx_gpio_free;
 261         chip->gc.direction_input = zx_direction_input;
 262         chip->gc.direction_output = zx_direction_output;
 263         chip->gc.get = zx_get_value;
 264         chip->gc.set = zx_set_value;
 265         chip->gc.base = ZX_GPIO_NR * id;
 266         chip->gc.ngpio = ZX_GPIO_NR;
 267         chip->gc.label = dev_name(dev);
 268         chip->gc.dev = dev;
 269         chip->gc.owner = THIS_MODULE;
 270
 271         ret = gpiochip_add(&chip->gc);
 272         if (ret)
 273                 return ret;
 274
 275         /*
 276          * irq_chip support
 277          */
 278         writew_relaxed(0xffff, chip->base + ZX_GPIO_IM);
 279         writew_relaxed(0, chip->base + ZX_GPIO_IE);
 280         irq = platform_get_irq(pdev, 0);
 281         if (irq < 0) {
 282                 dev_err(dev, "invalid IRQ\n");
 283                 gpiochip_remove(&chip->gc);
 284                 return -ENODEV;
 285         }
 286
 287         ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip,
 288                                    0, handle_simple_irq,
 289                                    IRQ_TYPE_NONE);
 290         if (ret) {
 291                 dev_err(dev, "could not add irqchip\n");
 292                 gpiochip_remove(&chip->gc);
 293                 return ret;
 294         }
 295         gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip,
 296                                      irq, zx_irq_handler);
 297
 298         platform_set_drvdata(pdev, chip);
 299         dev_info(dev, "ZX GPIO chip registered\n");
 300
 301         return 0;
 302 }
 303
 304 static const struct of_device_id zx_gpio_match[] = {
 305         {
 306                 .compatible = "zte,zx296702-gpio",
 307         },
 308         { },
 309 };
 310 MODULE_DEVICE_TABLE(of, zx_gpio_match);
 311
 312 static struct platform_driver zx_gpio_driver = {
 313         .probe          = zx_gpio_probe,
 314         .driver = {
 315                 .name   = "zx_gpio",
 316                 .of_match_table = of_match_ptr(zx_gpio_match),
 317         },
 318 };
 319
 320 module_platform_driver(zx_gpio_driver)
 321
 322 MODULE_AUTHOR("Jun Nie <jun.nie@linaro.org>");
 323 MODULE_DESCRIPTION("ZTE ZX296702 GPIO driver");
 324 MODULE_LICENSE("GPL");