drivers/gpio/gpio-zx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ZTE ZX296702 GPIO driver
   4  *
   5  * Author: Jun Nie <jun.nie@linaro.org>
   6  *
   7  * Copyright (C) 2015 Linaro Ltd.
   8  */
   9 #include <linux/bitops.h>
  10 #include <linux/device.h>
  11 #include <linux/errno.h>
  12 #include <linux/gpio/driver.h>
  13 #include <linux/irqchip/chained_irq.h>
  14 #include <linux/init.h>
  15 #include <linux/of.h>
  16 #include <linux/pinctrl/consumer.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/pm.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21
  22 #define ZX_GPIO_DIR     0x00
  23 #define ZX_GPIO_IVE     0x04
  24 #define ZX_GPIO_IV      0x08
  25 #define ZX_GPIO_IEP     0x0C
  26 #define ZX_GPIO_IEN     0x10
  27 #define ZX_GPIO_DI      0x14
  28 #define ZX_GPIO_DO1     0x18
  29 #define ZX_GPIO_DO0     0x1C
  30 #define ZX_GPIO_DO      0x20
  31
  32 #define ZX_GPIO_IM      0x28
  33 #define ZX_GPIO_IE      0x2C
  34
  35 #define ZX_GPIO_MIS     0x30
  36 #define ZX_GPIO_IC      0x34
  37
  38 #define ZX_GPIO_NR      16
  39
  40 struct zx_gpio {
  41         raw_spinlock_t          lock;
  42
  43         void __iomem            *base;
  44         struct gpio_chip        gc;
  45 };
  46
  47 static int zx_direction_input(struct gpio_chip *gc, unsigned offset)
  48 {
  49         struct zx_gpio *chip = gpiochip_get_data(gc);
  50         unsigned long flags;
  51         u16 gpiodir;
  52
  53         if (offset >= gc->ngpio)
  54                 return -EINVAL;
  55
  56         raw_spin_lock_irqsave(&chip->lock, flags);
  57         gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
  58         gpiodir &= ~BIT(offset);
  59         writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
  60         raw_spin_unlock_irqrestore(&chip->lock, flags);
  61
  62         return 0;
  63 }
  64
  65 static int zx_direction_output(struct gpio_chip *gc, unsigned offset,
  66                 int value)
  67 {
  68         struct zx_gpio *chip = gpiochip_get_data(gc);
  69         unsigned long flags;
  70         u16 gpiodir;
  71
  72         if (offset >= gc->ngpio)
  73                 return -EINVAL;
  74
  75         raw_spin_lock_irqsave(&chip->lock, flags);
  76         gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
  77         gpiodir |= BIT(offset);
  78         writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
  79
  80         if (value)
  81                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
  82         else
  83                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
  84         raw_spin_unlock_irqrestore(&chip->lock, flags);
  85
  86         return 0;
  87 }
  88
  89 static int zx_get_value(struct gpio_chip *gc, unsigned offset)
  90 {
  91         struct zx_gpio *chip = gpiochip_get_data(gc);
  92
  93         return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset));
  94 }
  95
  96 static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value)
  97 {
  98         struct zx_gpio *chip = gpiochip_get_data(gc);
  99
 100         if (value)
 101                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
 102         else
 103                 writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
 104 }
 105
 106 static int zx_irq_type(struct irq_data *d, unsigned trigger)
 107 {
 108         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 109         struct zx_gpio *chip = gpiochip_get_data(gc);
 110         int offset = irqd_to_hwirq(d);
 111         unsigned long flags;
 112         u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev;
 113         u16 bit = BIT(offset);
 114
 115         if (offset < 0 || offset >= ZX_GPIO_NR)
 116                 return -EINVAL;
 117
 118         raw_spin_lock_irqsave(&chip->lock, flags);
 119
 120         gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV);
 121         gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE);
 122         gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP);
 123         gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN);
 124
 125         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 126                 gpiois |= bit;
 127                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 128                         gpioiev |= bit;
 129                 else
 130                         gpioiev &= ~bit;
 131         } else
 132                 gpiois &= ~bit;
 133
 134         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 135                 gpioi_epos |= bit;
 136                 gpioi_eneg |= bit;
 137         } else {
 138                 if (trigger & IRQ_TYPE_EDGE_RISING) {
 139                         gpioi_epos |= bit;
 140                         gpioi_eneg &= ~bit;
 141                 } else if (trigger & IRQ_TYPE_EDGE_FALLING) {
 142                         gpioi_eneg |= bit;
 143                         gpioi_epos &= ~bit;
 144                 }
 145         }
 146
 147         writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE);
 148         writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP);
 149         writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN);
 150         writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV);
 151         raw_spin_unlock_irqrestore(&chip->lock, flags);
 152
 153         return 0;
 154 }
 155
 156 static void zx_irq_handler(struct irq_desc *desc)
 157 {
 158         unsigned long pending;
 159         int offset;
 160         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 161         struct zx_gpio *chip = gpiochip_get_data(gc);
 162         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 163
 164         chained_irq_enter(irqchip, desc);
 165
 166         pending = readw_relaxed(chip->base + ZX_GPIO_MIS);
 167         writew_relaxed(pending, chip->base + ZX_GPIO_IC);
 168         if (pending) {
 169                 for_each_set_bit(offset, &pending, ZX_GPIO_NR)
 170                         generic_handle_irq(irq_find_mapping(gc->irq.domain,
 171                                                             offset));
 172         }
 173
 174         chained_irq_exit(irqchip, desc);
 175 }
 176
 177 static void zx_irq_mask(struct irq_data *d)
 178 {
 179         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 180         struct zx_gpio *chip = gpiochip_get_data(gc);
 181         u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
 182         u16 gpioie;
 183
 184         raw_spin_lock(&chip->lock);
 185         gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask;
 186         writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
 187         gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask;
 188         writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
 189         raw_spin_unlock(&chip->lock);
 190 }
 191
 192 static void zx_irq_unmask(struct irq_data *d)
 193 {
 194         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 195         struct zx_gpio *chip = gpiochip_get_data(gc);
 196         u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
 197         u16 gpioie;
 198
 199         raw_spin_lock(&chip->lock);
 200         gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask;
 201         writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
 202         gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask;
 203         writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
 204         raw_spin_unlock(&chip->lock);
 205 }
 206
 207 static struct irq_chip zx_irqchip = {
 208         .name           = "zx-gpio",
 209         .irq_mask       = zx_irq_mask,
 210         .irq_unmask     = zx_irq_unmask,
 211         .irq_set_type   = zx_irq_type,
 212 };
 213
 214 static int zx_gpio_probe(struct platform_device *pdev)
 215 {
 216         struct device *dev = &pdev->dev;
 217         struct zx_gpio *chip;
 218         struct gpio_irq_chip *girq;
 219         int irq, id, ret;
 220
 221         chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 222         if (!chip)
 223                 return -ENOMEM;
 224
 225         chip->base = devm_platform_ioremap_resource(pdev, 0);
 226         if (IS_ERR(chip->base))
 227                 return PTR_ERR(chip->base);
 228
 229         raw_spin_lock_init(&chip->lock);
 230         if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
 231                 chip->gc.request = gpiochip_generic_request;
 232                 chip->gc.free = gpiochip_generic_free;
 233         }
 234
 235         id = of_alias_get_id(dev->of_node, "gpio");
 236         chip->gc.direction_input = zx_direction_input;
 237         chip->gc.direction_output = zx_direction_output;
 238         chip->gc.get = zx_get_value;
 239         chip->gc.set = zx_set_value;
 240         chip->gc.base = ZX_GPIO_NR * id;
 241         chip->gc.ngpio = ZX_GPIO_NR;
 242         chip->gc.label = dev_name(dev);
 243         chip->gc.parent = dev;
 244         chip->gc.owner = THIS_MODULE;
 245
 246         /*
 247          * irq_chip support
 248          */
 249         writew_relaxed(0xffff, chip->base + ZX_GPIO_IM);
 250         writew_relaxed(0, chip->base + ZX_GPIO_IE);
 251         irq = platform_get_irq(pdev, 0);
 252         if (irq < 0)
 253                 return irq;
 254         girq = &chip->gc.irq;
 255         girq->chip = &zx_irqchip;
 256         girq->parent_handler = zx_irq_handler;
 257         girq->num_parents = 1;
 258         girq->parents = devm_kcalloc(&pdev->dev, 1,
 259                                      sizeof(*girq->parents),
 260                                      GFP_KERNEL);
 261         if (!girq->parents)
 262                 return -ENOMEM;
 263         girq->parents[0] = irq;
 264         girq->default_type = IRQ_TYPE_NONE;
 265         girq->handler = handle_simple_irq;
 266
 267         ret = gpiochip_add_data(&chip->gc, chip);
 268         if (ret)
 269                 return ret;
 270
 271         platform_set_drvdata(pdev, chip);
 272         dev_info(dev, "ZX GPIO chip registered\n");
 273
 274         return 0;
 275 }
 276
 277 static const struct of_device_id zx_gpio_match[] = {
 278         {
 279                 .compatible = "zte,zx296702-gpio",
 280         },
 281         { },
 282 };
 283
 284 static struct platform_driver zx_gpio_driver = {
 285         .probe          = zx_gpio_probe,
 286         .driver = {
 287                 .name   = "zx_gpio",
 288                 .of_match_table = of_match_ptr(zx_gpio_match),
 289         },
 290 };
 291 builtin_platform_driver(zx_gpio_driver)