linux/drivers/gpio/gpio-tb10x.c
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   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 */
  41struct tb10x_gpio {
  42        void __iomem *base;
  43        struct irq_domain *domain;
  44        int irq;
  45        struct gpio_chip gc;
  46};
  47
  48static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
  49{
  50        return ioread32(gpio->base + offs);
  51}
  52
  53static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
  54                                u32 val)
  55{
  56        iowrite32(val, gpio->base + offs);
  57}
  58
  59static 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
  75static 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
  82static 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
  94static 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_domain_irq(tb10x_gpio->domain, i);
 104
 105        return IRQ_HANDLED;
 106}
 107
 108static 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
 214static 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
 228static const struct of_device_id tb10x_gpio_dt_ids[] = {
 229        { .compatible = "abilis,tb10x-gpio" },
 230        { }
 231};
 232MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
 233
 234static 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
 243module_platform_driver(tb10x_gpio_driver);
 244MODULE_LICENSE("GPL");
 245MODULE_DESCRIPTION("tb10x gpio.");
 246