linux/drivers/gpio/gpio-mt7621.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
   4 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   5 */
   6
   7#include <linux/err.h>
   8#include <linux/gpio/driver.h>
   9#include <linux/interrupt.h>
  10#include <linux/io.h>
  11#include <linux/module.h>
  12#include <linux/of_irq.h>
  13#include <linux/platform_device.h>
  14#include <linux/spinlock.h>
  15
  16#define MTK_BANK_CNT    3
  17#define MTK_BANK_WIDTH  32
  18
  19#define GPIO_BANK_STRIDE        0x04
  20#define GPIO_REG_CTRL           0x00
  21#define GPIO_REG_POL            0x10
  22#define GPIO_REG_DATA           0x20
  23#define GPIO_REG_DSET           0x30
  24#define GPIO_REG_DCLR           0x40
  25#define GPIO_REG_REDGE          0x50
  26#define GPIO_REG_FEDGE          0x60
  27#define GPIO_REG_HLVL           0x70
  28#define GPIO_REG_LLVL           0x80
  29#define GPIO_REG_STAT           0x90
  30#define GPIO_REG_EDGE           0xA0
  31
  32struct mtk_gc {
  33        struct irq_chip irq_chip;
  34        struct gpio_chip chip;
  35        spinlock_t lock;
  36        int bank;
  37        u32 rising;
  38        u32 falling;
  39        u32 hlevel;
  40        u32 llevel;
  41};
  42
  43/**
  44 * struct mtk - state container for
  45 * data of the platform driver. It is 3
  46 * separate gpio-chip each one with its
  47 * own irq_chip.
  48 * @dev: device instance
  49 * @base: memory base address
  50 * @gpio_irq: irq number from the device tree
  51 * @gc_map: array of the gpio chips
  52 */
  53struct mtk {
  54        struct device *dev;
  55        void __iomem *base;
  56        int gpio_irq;
  57        struct mtk_gc gc_map[MTK_BANK_CNT];
  58};
  59
  60static inline struct mtk_gc *
  61to_mediatek_gpio(struct gpio_chip *chip)
  62{
  63        return container_of(chip, struct mtk_gc, chip);
  64}
  65
  66static inline void
  67mtk_gpio_w32(struct mtk_gc *rg, u32 offset, u32 val)
  68{
  69        struct gpio_chip *gc = &rg->chip;
  70        struct mtk *mtk = gpiochip_get_data(gc);
  71
  72        offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
  73        gc->write_reg(mtk->base + offset, val);
  74}
  75
  76static inline u32
  77mtk_gpio_r32(struct mtk_gc *rg, u32 offset)
  78{
  79        struct gpio_chip *gc = &rg->chip;
  80        struct mtk *mtk = gpiochip_get_data(gc);
  81
  82        offset = (rg->bank * GPIO_BANK_STRIDE) + offset;
  83        return gc->read_reg(mtk->base + offset);
  84}
  85
  86static irqreturn_t
  87mediatek_gpio_irq_handler(int irq, void *data)
  88{
  89        struct gpio_chip *gc = data;
  90        struct mtk_gc *rg = to_mediatek_gpio(gc);
  91        irqreturn_t ret = IRQ_NONE;
  92        unsigned long pending;
  93        int bit;
  94
  95        pending = mtk_gpio_r32(rg, GPIO_REG_STAT);
  96
  97        for_each_set_bit(bit, &pending, MTK_BANK_WIDTH) {
  98                u32 map = irq_find_mapping(gc->irq.domain, bit);
  99
 100                generic_handle_irq(map);
 101                mtk_gpio_w32(rg, GPIO_REG_STAT, BIT(bit));
 102                ret |= IRQ_HANDLED;
 103        }
 104
 105        return ret;
 106}
 107
 108static void
 109mediatek_gpio_irq_unmask(struct irq_data *d)
 110{
 111        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 112        struct mtk_gc *rg = to_mediatek_gpio(gc);
 113        int pin = d->hwirq;
 114        unsigned long flags;
 115        u32 rise, fall, high, low;
 116
 117        spin_lock_irqsave(&rg->lock, flags);
 118        rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
 119        fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
 120        high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
 121        low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
 122        mtk_gpio_w32(rg, GPIO_REG_REDGE, rise | (BIT(pin) & rg->rising));
 123        mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall | (BIT(pin) & rg->falling));
 124        mtk_gpio_w32(rg, GPIO_REG_HLVL, high | (BIT(pin) & rg->hlevel));
 125        mtk_gpio_w32(rg, GPIO_REG_LLVL, low | (BIT(pin) & rg->llevel));
 126        spin_unlock_irqrestore(&rg->lock, flags);
 127}
 128
 129static void
 130mediatek_gpio_irq_mask(struct irq_data *d)
 131{
 132        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 133        struct mtk_gc *rg = to_mediatek_gpio(gc);
 134        int pin = d->hwirq;
 135        unsigned long flags;
 136        u32 rise, fall, high, low;
 137
 138        spin_lock_irqsave(&rg->lock, flags);
 139        rise = mtk_gpio_r32(rg, GPIO_REG_REDGE);
 140        fall = mtk_gpio_r32(rg, GPIO_REG_FEDGE);
 141        high = mtk_gpio_r32(rg, GPIO_REG_HLVL);
 142        low = mtk_gpio_r32(rg, GPIO_REG_LLVL);
 143        mtk_gpio_w32(rg, GPIO_REG_FEDGE, fall & ~BIT(pin));
 144        mtk_gpio_w32(rg, GPIO_REG_REDGE, rise & ~BIT(pin));
 145        mtk_gpio_w32(rg, GPIO_REG_HLVL, high & ~BIT(pin));
 146        mtk_gpio_w32(rg, GPIO_REG_LLVL, low & ~BIT(pin));
 147        spin_unlock_irqrestore(&rg->lock, flags);
 148}
 149
 150static int
 151mediatek_gpio_irq_type(struct irq_data *d, unsigned int type)
 152{
 153        struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 154        struct mtk_gc *rg = to_mediatek_gpio(gc);
 155        int pin = d->hwirq;
 156        u32 mask = BIT(pin);
 157
 158        if (type == IRQ_TYPE_PROBE) {
 159                if ((rg->rising | rg->falling |
 160                     rg->hlevel | rg->llevel) & mask)
 161                        return 0;
 162
 163                type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
 164        }
 165
 166        rg->rising &= ~mask;
 167        rg->falling &= ~mask;
 168        rg->hlevel &= ~mask;
 169        rg->llevel &= ~mask;
 170
 171        switch (type & IRQ_TYPE_SENSE_MASK) {
 172        case IRQ_TYPE_EDGE_BOTH:
 173                rg->rising |= mask;
 174                rg->falling |= mask;
 175                break;
 176        case IRQ_TYPE_EDGE_RISING:
 177                rg->rising |= mask;
 178                break;
 179        case IRQ_TYPE_EDGE_FALLING:
 180                rg->falling |= mask;
 181                break;
 182        case IRQ_TYPE_LEVEL_HIGH:
 183                rg->hlevel |= mask;
 184                break;
 185        case IRQ_TYPE_LEVEL_LOW:
 186                rg->llevel |= mask;
 187                break;
 188        }
 189
 190        return 0;
 191}
 192
 193static int
 194mediatek_gpio_xlate(struct gpio_chip *chip,
 195                    const struct of_phandle_args *spec, u32 *flags)
 196{
 197        int gpio = spec->args[0];
 198        struct mtk_gc *rg = to_mediatek_gpio(chip);
 199
 200        if (rg->bank != gpio / MTK_BANK_WIDTH)
 201                return -EINVAL;
 202
 203        if (flags)
 204                *flags = spec->args[1];
 205
 206        return gpio % MTK_BANK_WIDTH;
 207}
 208
 209static int
 210mediatek_gpio_bank_probe(struct device *dev,
 211                         struct device_node *node, int bank)
 212{
 213        struct mtk *mtk = dev_get_drvdata(dev);
 214        struct mtk_gc *rg;
 215        void __iomem *dat, *set, *ctrl, *diro;
 216        int ret;
 217
 218        rg = &mtk->gc_map[bank];
 219        memset(rg, 0, sizeof(*rg));
 220
 221        spin_lock_init(&rg->lock);
 222        rg->chip.of_node = node;
 223        rg->bank = bank;
 224
 225        dat = mtk->base + GPIO_REG_DATA + (rg->bank * GPIO_BANK_STRIDE);
 226        set = mtk->base + GPIO_REG_DSET + (rg->bank * GPIO_BANK_STRIDE);
 227        ctrl = mtk->base + GPIO_REG_DCLR + (rg->bank * GPIO_BANK_STRIDE);
 228        diro = mtk->base + GPIO_REG_CTRL + (rg->bank * GPIO_BANK_STRIDE);
 229
 230        ret = bgpio_init(&rg->chip, dev, 4, dat, set, ctrl, diro, NULL,
 231                         BGPIOF_NO_SET_ON_INPUT);
 232        if (ret) {
 233                dev_err(dev, "bgpio_init() failed\n");
 234                return ret;
 235        }
 236
 237        rg->chip.of_gpio_n_cells = 2;
 238        rg->chip.of_xlate = mediatek_gpio_xlate;
 239        rg->chip.label = devm_kasprintf(dev, GFP_KERNEL, "%s-bank%d",
 240                                        dev_name(dev), bank);
 241        if (!rg->chip.label)
 242                return -ENOMEM;
 243
 244        rg->irq_chip.name = dev_name(dev);
 245        rg->irq_chip.parent_device = dev;
 246        rg->irq_chip.irq_unmask = mediatek_gpio_irq_unmask;
 247        rg->irq_chip.irq_mask = mediatek_gpio_irq_mask;
 248        rg->irq_chip.irq_mask_ack = mediatek_gpio_irq_mask;
 249        rg->irq_chip.irq_set_type = mediatek_gpio_irq_type;
 250
 251        if (mtk->gpio_irq) {
 252                struct gpio_irq_chip *girq;
 253
 254                /*
 255                 * Directly request the irq here instead of passing
 256                 * a flow-handler because the irq is shared.
 257                 */
 258                ret = devm_request_irq(dev, mtk->gpio_irq,
 259                                       mediatek_gpio_irq_handler, IRQF_SHARED,
 260                                       rg->chip.label, &rg->chip);
 261
 262                if (ret) {
 263                        dev_err(dev, "Error requesting IRQ %d: %d\n",
 264                                mtk->gpio_irq, ret);
 265                        return ret;
 266                }
 267
 268                girq = &rg->chip.irq;
 269                girq->chip = &rg->irq_chip;
 270                /* This will let us handle the parent IRQ in the driver */
 271                girq->parent_handler = NULL;
 272                girq->num_parents = 0;
 273                girq->parents = NULL;
 274                girq->default_type = IRQ_TYPE_NONE;
 275                girq->handler = handle_simple_irq;
 276        }
 277
 278        ret = devm_gpiochip_add_data(dev, &rg->chip, mtk);
 279        if (ret < 0) {
 280                dev_err(dev, "Could not register gpio %d, ret=%d\n",
 281                        rg->chip.ngpio, ret);
 282                return ret;
 283        }
 284
 285        /* set polarity to low for all gpios */
 286        mtk_gpio_w32(rg, GPIO_REG_POL, 0);
 287
 288        dev_info(dev, "registering %d gpios\n", rg->chip.ngpio);
 289
 290        return 0;
 291}
 292
 293static int
 294mediatek_gpio_probe(struct platform_device *pdev)
 295{
 296        struct device *dev = &pdev->dev;
 297        struct device_node *np = dev->of_node;
 298        struct mtk *mtk;
 299        int i;
 300        int ret;
 301
 302        mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
 303        if (!mtk)
 304                return -ENOMEM;
 305
 306        mtk->base = devm_platform_ioremap_resource(pdev, 0);
 307        if (IS_ERR(mtk->base))
 308                return PTR_ERR(mtk->base);
 309
 310        mtk->gpio_irq = irq_of_parse_and_map(np, 0);
 311        mtk->dev = dev;
 312        platform_set_drvdata(pdev, mtk);
 313
 314        for (i = 0; i < MTK_BANK_CNT; i++) {
 315                ret = mediatek_gpio_bank_probe(dev, np, i);
 316                if (ret)
 317                        return ret;
 318        }
 319
 320        return 0;
 321}
 322
 323static const struct of_device_id mediatek_gpio_match[] = {
 324        { .compatible = "mediatek,mt7621-gpio" },
 325        {},
 326};
 327MODULE_DEVICE_TABLE(of, mediatek_gpio_match);
 328
 329static struct platform_driver mediatek_gpio_driver = {
 330        .probe = mediatek_gpio_probe,
 331        .driver = {
 332                .name = "mt7621_gpio",
 333                .of_match_table = mediatek_gpio_match,
 334        },
 335};
 336
 337builtin_platform_driver(mediatek_gpio_driver);
 338