drivers/gpio/gpio-zx.c

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