drivers/gpio/gpio-ath79.c

   1 /*
   2  *  Atheros AR71XX/AR724X/AR913X GPIO API support
   3  *
   4  *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
   5  *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
   6  *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
   7  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify it
  10  *  under the terms of the GNU General Public License version 2 as published
  11  *  by the Free Software Foundation.
  12  */
  13
  14 #include <linux/gpio/driver.h>
  15 #include <linux/platform_data/gpio-ath79.h>
  16 #include <linux/of_device.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/module.h>
  19 #include <linux/irq.h>
  20
  21 #define AR71XX_GPIO_REG_OE              0x00
  22 #define AR71XX_GPIO_REG_IN              0x04
  23 #define AR71XX_GPIO_REG_SET             0x0c
  24 #define AR71XX_GPIO_REG_CLEAR           0x10
  25
  26 #define AR71XX_GPIO_REG_INT_ENABLE      0x14
  27 #define AR71XX_GPIO_REG_INT_TYPE        0x18
  28 #define AR71XX_GPIO_REG_INT_POLARITY    0x1c
  29 #define AR71XX_GPIO_REG_INT_PENDING     0x20
  30 #define AR71XX_GPIO_REG_INT_MASK        0x24
  31
  32 struct ath79_gpio_ctrl {
  33         struct gpio_chip gc;
  34         void __iomem *base;
  35         raw_spinlock_t lock;
  36         unsigned long both_edges;
  37 };
  38
  39 static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data)
  40 {
  41         struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
  42
  43         return container_of(gc, struct ath79_gpio_ctrl, gc);
  44 }
  45
  46 static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg)
  47 {
  48         return readl(ctrl->base + reg);
  49 }
  50
  51 static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl,
  52                         unsigned reg, u32 val)
  53 {
  54         return writel(val, ctrl->base + reg);
  55 }
  56
  57 static bool ath79_gpio_update_bits(
  58         struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits)
  59 {
  60         u32 old_val, new_val;
  61
  62         old_val = ath79_gpio_read(ctrl, reg);
  63         new_val = (old_val & ~mask) | (bits & mask);
  64
  65         if (new_val != old_val)
  66                 ath79_gpio_write(ctrl, reg, new_val);
  67
  68         return new_val != old_val;
  69 }
  70
  71 static void ath79_gpio_irq_unmask(struct irq_data *data)
  72 {
  73         struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  74         u32 mask = BIT(irqd_to_hwirq(data));
  75         unsigned long flags;
  76
  77         raw_spin_lock_irqsave(&ctrl->lock, flags);
  78         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
  79         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
  80 }
  81
  82 static void ath79_gpio_irq_mask(struct irq_data *data)
  83 {
  84         struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  85         u32 mask = BIT(irqd_to_hwirq(data));
  86         unsigned long flags;
  87
  88         raw_spin_lock_irqsave(&ctrl->lock, flags);
  89         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
  90         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
  91 }
  92
  93 static void ath79_gpio_irq_enable(struct irq_data *data)
  94 {
  95         struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
  96         u32 mask = BIT(irqd_to_hwirq(data));
  97         unsigned long flags;
  98
  99         raw_spin_lock_irqsave(&ctrl->lock, flags);
 100         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 101         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask);
 102         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 103 }
 104
 105 static void ath79_gpio_irq_disable(struct irq_data *data)
 106 {
 107         struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 108         u32 mask = BIT(irqd_to_hwirq(data));
 109         unsigned long flags;
 110
 111         raw_spin_lock_irqsave(&ctrl->lock, flags);
 112         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0);
 113         ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
 114         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 115 }
 116
 117 static int ath79_gpio_irq_set_type(struct irq_data *data,
 118                                 unsigned int flow_type)
 119 {
 120         struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data);
 121         u32 mask = BIT(irqd_to_hwirq(data));
 122         u32 type = 0, polarity = 0;
 123         unsigned long flags;
 124         bool disabled;
 125
 126         switch (flow_type) {
 127         case IRQ_TYPE_EDGE_RISING:
 128                 polarity |= mask;
 129         case IRQ_TYPE_EDGE_FALLING:
 130         case IRQ_TYPE_EDGE_BOTH:
 131                 break;
 132
 133         case IRQ_TYPE_LEVEL_HIGH:
 134                 polarity |= mask;
 135                 /* fall through */
 136         case IRQ_TYPE_LEVEL_LOW:
 137                 type |= mask;
 138                 break;
 139
 140         default:
 141                 return -EINVAL;
 142         }
 143
 144         raw_spin_lock_irqsave(&ctrl->lock, flags);
 145
 146         if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 147                 ctrl->both_edges |= mask;
 148                 polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 149         } else {
 150                 ctrl->both_edges &= ~mask;
 151         }
 152
 153         /* As the IRQ configuration can't be loaded atomically we
 154          * have to disable the interrupt while the configuration state
 155          * is invalid.
 156          */
 157         disabled = ath79_gpio_update_bits(
 158                 ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0);
 159
 160         ath79_gpio_update_bits(
 161                 ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type);
 162         ath79_gpio_update_bits(
 163                 ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity);
 164
 165         if (disabled)
 166                 ath79_gpio_update_bits(
 167                         ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask);
 168
 169         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 170
 171         return 0;
 172 }
 173
 174 static struct irq_chip ath79_gpio_irqchip = {
 175         .name = "gpio-ath79",
 176         .irq_enable = ath79_gpio_irq_enable,
 177         .irq_disable = ath79_gpio_irq_disable,
 178         .irq_mask = ath79_gpio_irq_mask,
 179         .irq_unmask = ath79_gpio_irq_unmask,
 180         .irq_set_type = ath79_gpio_irq_set_type,
 181 };
 182
 183 static void ath79_gpio_irq_handler(struct irq_desc *desc)
 184 {
 185         struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 186         struct irq_chip *irqchip = irq_desc_get_chip(desc);
 187         struct ath79_gpio_ctrl *ctrl =
 188                 container_of(gc, struct ath79_gpio_ctrl, gc);
 189         unsigned long flags, pending;
 190         u32 both_edges, state;
 191         int irq;
 192
 193         chained_irq_enter(irqchip, desc);
 194
 195         raw_spin_lock_irqsave(&ctrl->lock, flags);
 196
 197         pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING);
 198
 199         /* Update the polarity of the both edges irqs */
 200         both_edges = ctrl->both_edges & pending;
 201         if (both_edges) {
 202                 state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN);
 203                 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY,
 204                                 both_edges, ~state);
 205         }
 206
 207         raw_spin_unlock_irqrestore(&ctrl->lock, flags);
 208
 209         if (pending) {
 210                 for_each_set_bit(irq, &pending, gc->ngpio)
 211                         generic_handle_irq(
 212                                 irq_linear_revmap(gc->irq.domain, irq));
 213         }
 214
 215         chained_irq_exit(irqchip, desc);
 216 }
 217
 218 static const struct of_device_id ath79_gpio_of_match[] = {
 219         { .compatible = "qca,ar7100-gpio" },
 220         { .compatible = "qca,ar9340-gpio" },
 221         {},
 222 };
 223 MODULE_DEVICE_TABLE(of, ath79_gpio_of_match);
 224
 225 static int ath79_gpio_probe(struct platform_device *pdev)
 226 {
 227         struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 228         struct device_node *np = pdev->dev.of_node;
 229         struct ath79_gpio_ctrl *ctrl;
 230         struct resource *res;
 231         u32 ath79_gpio_count;
 232         bool oe_inverted;
 233         int err;
 234
 235         ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL);
 236         if (!ctrl)
 237                 return -ENOMEM;
 238         platform_set_drvdata(pdev, ctrl);
 239
 240         if (np) {
 241                 err = of_property_read_u32(np, "ngpios", &ath79_gpio_count);
 242                 if (err) {
 243                         dev_err(&pdev->dev, "ngpios property is not valid\n");
 244                         return err;
 245                 }
 246                 oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio");
 247         } else if (pdata) {
 248                 ath79_gpio_count = pdata->ngpios;
 249                 oe_inverted = pdata->oe_inverted;
 250         } else {
 251                 dev_err(&pdev->dev, "No DT node or platform data found\n");
 252                 return -EINVAL;
 253         }
 254
 255         if (ath79_gpio_count >= 32) {
 256                 dev_err(&pdev->dev, "ngpios must be less than 32\n");
 257                 return -EINVAL;
 258         }
 259
 260         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 261         ctrl->base = devm_ioremap_nocache(
 262                 &pdev->dev, res->start, resource_size(res));
 263         if (!ctrl->base)
 264                 return -ENOMEM;
 265
 266         raw_spin_lock_init(&ctrl->lock);
 267         err = bgpio_init(&ctrl->gc, &pdev->dev, 4,
 268                         ctrl->base + AR71XX_GPIO_REG_IN,
 269                         ctrl->base + AR71XX_GPIO_REG_SET,
 270                         ctrl->base + AR71XX_GPIO_REG_CLEAR,
 271                         oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE,
 272                         oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL,
 273                         0);
 274         if (err) {
 275                 dev_err(&pdev->dev, "bgpio_init failed\n");
 276                 return err;
 277         }
 278         /* Use base 0 to stay compatible with legacy platforms */
 279         ctrl->gc.base = 0;
 280
 281         err = gpiochip_add_data(&ctrl->gc, ctrl);
 282         if (err) {
 283                 dev_err(&pdev->dev,
 284                         "cannot add AR71xx GPIO chip, error=%d", err);
 285                 return err;
 286         }
 287
 288         if (np && !of_property_read_bool(np, "interrupt-controller"))
 289                 return 0;
 290
 291         err = gpiochip_irqchip_add(&ctrl->gc, &ath79_gpio_irqchip, 0,
 292                                 handle_simple_irq, IRQ_TYPE_NONE);
 293         if (err) {
 294                 dev_err(&pdev->dev, "failed to add gpiochip_irqchip\n");
 295                 goto gpiochip_remove;
 296         }
 297
 298         gpiochip_set_chained_irqchip(&ctrl->gc, &ath79_gpio_irqchip,
 299                                 platform_get_irq(pdev, 0),
 300                                 ath79_gpio_irq_handler);
 301
 302         return 0;
 303
 304 gpiochip_remove:
 305         gpiochip_remove(&ctrl->gc);
 306         return err;
 307 }
 308
 309 static int ath79_gpio_remove(struct platform_device *pdev)
 310 {
 311         struct ath79_gpio_ctrl *ctrl = platform_get_drvdata(pdev);
 312
 313         gpiochip_remove(&ctrl->gc);
 314         return 0;
 315 }
 316
 317 static struct platform_driver ath79_gpio_driver = {
 318         .driver = {
 319                 .name = "ath79-gpio",
 320                 .of_match_table = ath79_gpio_of_match,
 321         },
 322         .probe = ath79_gpio_probe,
 323         .remove = ath79_gpio_remove,
 324 };
 325
 326 module_platform_driver(ath79_gpio_driver);