drivers/gpio/gpio-tb10x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Abilis Systems MODULE DESCRIPTION
   3  *
   4  * Copyright (C) Abilis Systems 2013
   5  *
   6  * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
   7  *          Christian Ruppert <christian.ruppert@abilis.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/gpio/driver.h>
  14 #include <linux/slab.h>
  15 #include <linux/irq.h>
  16 #include <linux/irqdomain.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/of.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/bitops.h>
  23 #include <linux/pinctrl/consumer.h>
  24
  25 #define TB10X_GPIO_DIR_IN       (0x00000000)
  26 #define TB10X_GPIO_DIR_OUT      (0x00000001)
  27 #define OFFSET_TO_REG_DDR       (0x00)
  28 #define OFFSET_TO_REG_DATA      (0x04)
  29 #define OFFSET_TO_REG_INT_EN    (0x08)
  30 #define OFFSET_TO_REG_CHANGE    (0x0C)
  31 #define OFFSET_TO_REG_WRMASK    (0x10)
  32 #define OFFSET_TO_REG_INT_TYPE  (0x14)
  33
  34
  35 /**
  36  * @base: register base address
  37  * @domain: IRQ domain of GPIO generated interrupts managed by this controller
  38  * @irq: Interrupt line of parent interrupt controller
  39  * @gc: gpio_chip structure associated to this GPIO controller
  40  */
  41 struct tb10x_gpio {
  42         void __iomem *base;
  43         struct irq_domain *domain;
  44         int irq;
  45         struct gpio_chip gc;
  46 };
  47
  48 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
  49 {
  50         return ioread32(gpio->base + offs);
  51 }
  52
  53 static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
  54                                 u32 val)
  55 {
  56         iowrite32(val, gpio->base + offs);
  57 }
  58
  59 static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
  60                                 u32 mask, u32 val)
  61 {
  62         u32 r;
  63         unsigned long flags;
  64
  65         spin_lock_irqsave(&gpio->gc.bgpio_lock, flags);
  66
  67         r = tb10x_reg_read(gpio, offs);
  68         r = (r & ~mask) | (val & mask);
  69
  70         tb10x_reg_write(gpio, offs, r);
  71
  72         spin_unlock_irqrestore(&gpio->gc.bgpio_lock, flags);
  73 }
  74
  75 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
  76 {
  77         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
  78
  79         return irq_create_mapping(tb10x_gpio->domain, offset);
  80 }
  81
  82 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
  83 {
  84         if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
  85                 pr_err("Only (both) edge triggered interrupts supported.\n");
  86                 return -EINVAL;
  87         }
  88
  89         irqd_set_trigger_type(data, type);
  90
  91         return IRQ_SET_MASK_OK;
  92 }
  93
  94 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
  95 {
  96         struct tb10x_gpio *tb10x_gpio = data;
  97         u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
  98         u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
  99         const unsigned long bits = r & m;
 100         int i;
 101
 102         for_each_set_bit(i, &bits, 32)
 103                 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 static int tb10x_gpio_probe(struct platform_device *pdev)
 109 {
 110         struct tb10x_gpio *tb10x_gpio;
 111         struct device *dev = &pdev->dev;
 112         struct device_node *np = dev->of_node;
 113         int ret = -EBUSY;
 114         u32 ngpio;
 115
 116         if (!np)
 117                 return -EINVAL;
 118
 119         if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
 120                 return -EINVAL;
 121
 122         tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
 123         if (tb10x_gpio == NULL)
 124                 return -ENOMEM;
 125
 126         tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
 127         if (IS_ERR(tb10x_gpio->base))
 128                 return PTR_ERR(tb10x_gpio->base);
 129
 130         tb10x_gpio->gc.label =
 131                 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
 132         if (!tb10x_gpio->gc.label)
 133                 return -ENOMEM;
 134
 135         /*
 136          * Initialize generic GPIO with one single register for reading and setting
 137          * the lines, no special set or clear registers and a data direction register
 138          * wher 1 means "output".
 139          */
 140         ret = bgpio_init(&tb10x_gpio->gc, dev, 4,
 141                          tb10x_gpio->base + OFFSET_TO_REG_DATA,
 142                          NULL,
 143                          NULL,
 144                          tb10x_gpio->base + OFFSET_TO_REG_DDR,
 145                          NULL,
 146                          0);
 147         if (ret) {
 148                 dev_err(dev, "unable to init generic GPIO\n");
 149                 return ret;
 150         }
 151         tb10x_gpio->gc.base = -1;
 152         tb10x_gpio->gc.parent = dev;
 153         tb10x_gpio->gc.owner = THIS_MODULE;
 154         /*
 155          * ngpio is set by bgpio_init() but we override it, this .request()
 156          * callback also overrides the one set up by generic GPIO.
 157          */
 158         tb10x_gpio->gc.ngpio = ngpio;
 159         tb10x_gpio->gc.request = gpiochip_generic_request;
 160         tb10x_gpio->gc.free = gpiochip_generic_free;
 161
 162         ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
 163         if (ret < 0) {
 164                 dev_err(dev, "Could not add gpiochip.\n");
 165                 return ret;
 166         }
 167
 168         platform_set_drvdata(pdev, tb10x_gpio);
 169
 170         if (of_find_property(np, "interrupt-controller", NULL)) {
 171                 struct irq_chip_generic *gc;
 172
 173                 ret = platform_get_irq(pdev, 0);
 174                 if (ret < 0)
 175                         return ret;
 176
 177                 tb10x_gpio->gc.to_irq   = tb10x_gpio_to_irq;
 178                 tb10x_gpio->irq         = ret;
 179
 180                 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
 181                                 IRQF_TRIGGER_NONE | IRQF_SHARED,
 182                                 dev_name(dev), tb10x_gpio);
 183                 if (ret != 0)
 184                         return ret;
 185
 186                 tb10x_gpio->domain = irq_domain_add_linear(np,
 187                                                 tb10x_gpio->gc.ngpio,
 188                                                 &irq_generic_chip_ops, NULL);
 189                 if (!tb10x_gpio->domain) {
 190                         return -ENOMEM;
 191                 }
 192
 193                 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
 194                                 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
 195                                 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
 196                                 IRQ_GC_INIT_MASK_CACHE);
 197                 if (ret)
 198                         return ret;
 199
 200                 gc = tb10x_gpio->domain->gc->gc[0];
 201                 gc->reg_base                         = tb10x_gpio->base;
 202                 gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
 203                 gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
 204                 gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
 205                 gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
 206                 gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
 207                 gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
 208                 gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
 209         }
 210
 211         return 0;
 212 }
 213
 214 static int tb10x_gpio_remove(struct platform_device *pdev)
 215 {
 216         struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
 217
 218         if (tb10x_gpio->gc.to_irq) {
 219                 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
 220                                         BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
 221                 kfree(tb10x_gpio->domain->gc);
 222                 irq_domain_remove(tb10x_gpio->domain);
 223         }
 224
 225         return 0;
 226 }
 227
 228 static const struct of_device_id tb10x_gpio_dt_ids[] = {
 229         { .compatible = "abilis,tb10x-gpio" },
 230         { }
 231 };
 232 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
 233
 234 static struct platform_driver tb10x_gpio_driver = {
 235         .probe          = tb10x_gpio_probe,
 236         .remove         = tb10x_gpio_remove,
 237         .driver = {
 238                 .name   = "tb10x-gpio",
 239                 .of_match_table = tb10x_gpio_dt_ids,
 240         }
 241 };
 242
 243 module_platform_driver(tb10x_gpio_driver);
 244 MODULE_LICENSE("GPL");
 245 MODULE_DESCRIPTION("tb10x gpio.");