linux/drivers/gpio/gpio-ath79.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Atheros AR71XX/AR724X/AR913X GPIO API support
   4 *
   5 *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
   6 *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
   7 *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
   8 *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   9 */
  10
  11#include <linux/gpio/driver.h>
  12#include <linux/platform_data/gpio-ath79.h>
  13#include <linux/of_device.h>
  14#include <linux/interrupt.h>
  15#include <linux/module.h>
  16#include <linux/irq.h>
  17
  18#define AR71XX_GPIO_REG_OE              0x00
  19#define AR71XX_GPIO_REG_IN              0x04
  20#define AR71XX_GPIO_REG_SET             0x0c
  21#define AR71XX_GPIO_REG_CLEAR           0x10
  22
  23#define AR71XX_GPIO_REG_INT_ENABLE      0x14
  24#define AR71XX_GPIO_REG_INT_TYPE        0x18
  25#define AR71XX_GPIO_REG_INT_POLARITY    0x1c
  26#define AR71XX_GPIO_REG_INT_PENDING     0x20
  27#define AR71XX_GPIO_REG_INT_MASK        0x24
  28
  29struct ath79_gpio_ctrl {
  30        struct gpio_chip gc;
  31        void __iomem *base;
  32        raw_spinlock_t lock;
  33        unsigned long both_edges;
  34};
  35
  36static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data)
  37{
  38        struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
  39
  40        return container_of(gc, struct ath79_gpio_ctrl, gc);
  41}
  42
  43static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
  44{
  45        return readl(ctrl->base + reg);
  46}
  47
  48static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
  49                        unsigned reg, u32 val)
  50{
  51        writel(val, ctrl->base + reg);
  52}
  53
  54static bool ath79_gpio_update_bits(
  55        struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
  56{
  57        u32 old_val, new_val;
  58
  59        old_val = ath79_gpio_read(ctrl, reg);
  60        new_val = (old_val & ~mask) | (bits & mask);
  61
  62        if (new_val != old_val)
  63                ath79_gpio_write(ctrl, reg, new_val);
  64
  65        return new_val != old_val;
  66}
  67
  68static void ath79_gpio_irq_unmask(struct irq_data *data)
  69{
  70        struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  71        u32 mask = BIT(irqd_to_hwirq(data));
  72        unsigned long flags;
  73
  74        raw_spin_lock_irqsave(&ctrl->lock, flags);
  75        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
  76        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
  77}
  78
  79static void ath79_gpio_irq_mask(struct irq_data *data)
  80{
  81        struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  82        u32 mask = BIT(irqd_to_hwirq(data));
  83        unsigned long flags;
  84
  85        raw_spin_lock_irqsave(&ctrl->lock, flags);
  86        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
  87        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
  88}
  89
  90static void ath79_gpio_irq_enable(struct irq_data *data)
  91{
  92        struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  93        u32 mask = BIT(irqd_to_hwirq(data));
  94        unsigned long flags;
  95
  96        raw_spin_lock_irqsave(&ctrl->lock, flags);
  97        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
  98        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
  99        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 100}
 101
 102static void ath79_gpio_irq_disable(struct irq_data *data)
 103{
 104        struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 105        u32 mask = BIT(irqd_to_hwirq(data));
 106        unsigned long flags;
 107
 108        raw_spin_lock_irqsave(&ctrl->lock, flags);
 109        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
 110        ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
 111        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 112}
 113
 114static int ath79_gpio_irq_set_type(struct irq_data *data,
 115                                unsigned int flow_type)
 116{
 117        struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 118        u32 mask = BIT(irqd_to_hwirq(data));
 119        u32 type = 0, polarity = 0;
 120        unsigned long flags;
 121        bool disabled;
 122
 123        switch (flow_type) {
 124        case IRQ_TYPE_EDGE_RISING:
 125                polarity |= mask;
 126        case IRQ_TYPE_EDGE_FALLING:
 127        case IRQ_TYPE_EDGE_BOTH:
 128                break;
 129
 130        case IRQ_TYPE_LEVEL_HIGH:
 131                polarity |= mask;
 132                fallthrough;
 133        case IRQ_TYPE_LEVEL_LOW:
 134                type |= mask;
 135                break;
 136
 137        default:
 138                return -EINVAL;
 139        }
 140
 141        raw_spin_lock_irqsave(&ctrl->lock, flags);
 142
 143        if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 144                ctrl->both_edges |= mask;
 145                polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 146        } else {
 147                ctrl->both_edges &= ~mask;
 148        }
 149
 150        /* As the IRQ configuration can't be loaded atomically we
 151         * have to disable the interrupt while the configuration state
 152         * is invalid.
 153         */
 154        disabled = ath79_gpio_update_bits(
 155                ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
 156
 157        ath79_gpio_update_bits(
 158                ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
 159        ath79_gpio_update_bits(
 160                ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);
 161
 162        if (disabled)
 163                ath79_gpio_update_bits(
 164                        ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 165
 166        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 167
 168        return 0;
 169}
 170
 171static struct irq_chip ath79_gpio_irqchip = {
 172        .name = "gpio-ath79",
 173        .irq_enable = ath79_gpio_irq_enable,
 174        .irq_disable = ath79_gpio_irq_disable,
 175        .irq_mask = ath79_gpio_irq_mask,
 176        .irq_unmask = ath79_gpio_irq_unmask,
 177        .irq_set_type = ath79_gpio_irq_set_type,
 178};
 179
 180static void ath79_gpio_irq_handler(struct irq_desc *desc)
 181{
 182        struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 183        struct irq_chip *irqchip = irq_desc_get_chip(desc);
 184        struct ath79_gpio_ctrl *ctrl =
 185                container_of(gc, struct ath79_gpio_ctrl, gc);
 186        unsigned long flags, pending;
 187        u32 both_edges, state;
 188        int irq;
 189
 190        chained_irq_enter(irqchip, desc);
 191
 192        raw_spin_lock_irqsave(&ctrl->lock, flags);
 193
 194        pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);
 195
 196        /* Update the polarity of the both edges irqs */
 197        both_edges = ctrl->both_edges & pending;
 198        if (both_edges) {
 199                state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 200                ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
 201                                both_edges, ~state);
 202        }
 203
 204        raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 205
 206        if (pending) {
 207                for_each_set_bit(irq, &pending, gc->ngpio)
 208                        generic_handle_irq(
 209                                irq_linear_revmap(gc->irq.domain, irq));
 210        }
 211
 212        chained_irq_exit(irqchip, desc);
 213}
 214
 215static const struct of_device_id ath79_gpio_of_match[] = {
 216        { .compatible = "qca,ar7100-gpio" },
 217        { .compatible = "qca,ar9340-gpio" },
 218        {},
 219};
 220MODULE_DEVICE_TABLE(of, ath79_gpio_of_match);
 221
 222static int ath79_gpio_probe(struct platform_device *pdev)
 223{
 224        struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 225        struct device *dev = &pdev->dev;
 226        struct device_node *np = dev->of_node;
 227        struct ath79_gpio_ctrl *ctrl;
 228        struct gpio_irq_chip *girq;
 229        u32 ath79_gpio_count;
 230        bool oe_inverted;
 231        int err;
 232
 233        ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
 234        if (!ctrl)
 235                return -ENOMEM;
 236        platform_set_drvdata(pdev, ctrl);
 237
 238        if (np) {
 239                err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
 240                if (err) {
 241                        dev_err(dev, "ngpios property is not valid\n");
 242                        return err;
 243                }
 244                oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
 245        } else if (pdata) {
 246                ath79_gpio_count = pdata->ngpios;
 247                oe_inverted = pdata->oe_inverted;
 248        } else {
 249                dev_err(dev, "No DT node or platform data found\n");
 250                return -EINVAL;
 251        }
 252
 253        if (ath79_gpio_count >= 32) {
 254                dev_err(dev, "ngpios must be less than 32\n");
 255                return -EINVAL;
 256        }
 257
 258        ctrl->base = devm_platform_ioremap_resource(pdev, 0);
 259        if (IS_ERR(ctrl->base))
 260                return PTR_ERR(ctrl->base);
 261
 262        raw_spin_lock_init(&ctrl->lock);
 263        err = bgpio_init(&ctrl->gc, dev, 4,
 264                        ctrl->base + AR71XX_GPIO_REG_IN,
 265                        ctrl->base + AR71XX_GPIO_REG_SET,
 266                        ctrl->base + AR71XX_GPIO_REG_CLEAR,
 267                        oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
 268                        oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
 269                        0);
 270        if (err) {
 271                dev_err(dev, "bgpio_init failed\n");
 272                return err;
 273        }
 274        /* Use base 0 to stay compatible with legacy platforms */
 275        ctrl->gc.base = 0;
 276
 277        /* Optional interrupt setup */
 278        if (!np || of_property_read_bool(np, "interrupt-controller")) {
 279                girq = &ctrl->gc.irq;
 280                girq->chip = &ath79_gpio_irqchip;
 281                girq->parent_handler = ath79_gpio_irq_handler;
 282                girq->num_parents = 1;
 283                girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents),
 284                                             GFP_KERNEL);
 285                if (!girq->parents)
 286                        return -ENOMEM;
 287                girq->parents[0] = platform_get_irq(pdev, 0);
 288                girq->default_type = IRQ_TYPE_NONE;
 289                girq->handler = handle_simple_irq;
 290        }
 291
 292        err = devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
 293        if (err) {
 294                dev_err(dev,
 295                        "cannot add AR71xx GPIO chip, error=%d", err);
 296                return err;
 297        }
 298        return 0;
 299}
 300
 301static struct platform_driver ath79_gpio_driver = {
 302        .driver = {
 303                .name = "ath79-gpio",
 304                .of_match_table = ath79_gpio_of_match,
 305        },
 306        .probe = ath79_gpio_probe,
 307};
 308
 309module_platform_driver(ath79_gpio_driver);
 310
 311MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X GPIO API support");
 312MODULE_LICENSE("GPL v2");
 313