linux/arch/arm/plat-pxa/gpio.c
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   1/*
   2 *  linux/arch/arm/plat-pxa/gpio.c
   3 *
   4 *  Generic PXA GPIO handling
   5 *
   6 *  Author:     Nicolas Pitre
   7 *  Created:    Jun 15, 2001
   8 *  Copyright:  MontaVista Software Inc.
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License version 2 as
  12 *  published by the Free Software Foundation.
  13 */
  14
  15#include <linux/init.h>
  16#include <linux/irq.h>
  17#include <linux/io.h>
  18#include <linux/sysdev.h>
  19#include <linux/slab.h>
  20
  21#include <mach/gpio.h>
  22
  23int pxa_last_gpio;
  24
  25struct pxa_gpio_chip {
  26        struct gpio_chip chip;
  27        void __iomem    *regbase;
  28        char label[10];
  29
  30        unsigned long   irq_mask;
  31        unsigned long   irq_edge_rise;
  32        unsigned long   irq_edge_fall;
  33
  34#ifdef CONFIG_PM
  35        unsigned long   saved_gplr;
  36        unsigned long   saved_gpdr;
  37        unsigned long   saved_grer;
  38        unsigned long   saved_gfer;
  39#endif
  40};
  41
  42static DEFINE_SPINLOCK(gpio_lock);
  43static struct pxa_gpio_chip *pxa_gpio_chips;
  44
  45#define for_each_gpio_chip(i, c)                        \
  46        for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
  47
  48static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
  49{
  50        return container_of(c, struct pxa_gpio_chip, chip)->regbase;
  51}
  52
  53static inline struct pxa_gpio_chip *gpio_to_chip(unsigned gpio)
  54{
  55        return &pxa_gpio_chips[gpio_to_bank(gpio)];
  56}
  57
  58static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
  59{
  60        void __iomem *base = gpio_chip_base(chip);
  61        uint32_t value, mask = 1 << offset;
  62        unsigned long flags;
  63
  64        spin_lock_irqsave(&gpio_lock, flags);
  65
  66        value = __raw_readl(base + GPDR_OFFSET);
  67        if (__gpio_is_inverted(chip->base + offset))
  68                value |= mask;
  69        else
  70                value &= ~mask;
  71        __raw_writel(value, base + GPDR_OFFSET);
  72
  73        spin_unlock_irqrestore(&gpio_lock, flags);
  74        return 0;
  75}
  76
  77static int pxa_gpio_direction_output(struct gpio_chip *chip,
  78                                     unsigned offset, int value)
  79{
  80        void __iomem *base = gpio_chip_base(chip);
  81        uint32_t tmp, mask = 1 << offset;
  82        unsigned long flags;
  83
  84        __raw_writel(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
  85
  86        spin_lock_irqsave(&gpio_lock, flags);
  87
  88        tmp = __raw_readl(base + GPDR_OFFSET);
  89        if (__gpio_is_inverted(chip->base + offset))
  90                tmp &= ~mask;
  91        else
  92                tmp |= mask;
  93        __raw_writel(tmp, base + GPDR_OFFSET);
  94
  95        spin_unlock_irqrestore(&gpio_lock, flags);
  96        return 0;
  97}
  98
  99static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
 100{
 101        return __raw_readl(gpio_chip_base(chip) + GPLR_OFFSET) & (1 << offset);
 102}
 103
 104static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 105{
 106        __raw_writel(1 << offset, gpio_chip_base(chip) +
 107                                (value ? GPSR_OFFSET : GPCR_OFFSET));
 108}
 109
 110static int __init pxa_init_gpio_chip(int gpio_end)
 111{
 112        int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
 113        struct pxa_gpio_chip *chips;
 114
 115        chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL);
 116        if (chips == NULL) {
 117                pr_err("%s: failed to allocate GPIO chips\n", __func__);
 118                return -ENOMEM;
 119        }
 120
 121        for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
 122                struct gpio_chip *c = &chips[i].chip;
 123
 124                sprintf(chips[i].label, "gpio-%d", i);
 125                chips[i].regbase = (void __iomem *)GPIO_BANK(i);
 126
 127                c->base  = gpio;
 128                c->label = chips[i].label;
 129
 130                c->direction_input  = pxa_gpio_direction_input;
 131                c->direction_output = pxa_gpio_direction_output;
 132                c->get = pxa_gpio_get;
 133                c->set = pxa_gpio_set;
 134
 135                /* number of GPIOs on last bank may be less than 32 */
 136                c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
 137                gpiochip_add(c);
 138        }
 139        pxa_gpio_chips = chips;
 140        return 0;
 141}
 142
 143/* Update only those GRERx and GFERx edge detection register bits if those
 144 * bits are set in c->irq_mask
 145 */
 146static inline void update_edge_detect(struct pxa_gpio_chip *c)
 147{
 148        uint32_t grer, gfer;
 149
 150        grer = __raw_readl(c->regbase + GRER_OFFSET) & ~c->irq_mask;
 151        gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~c->irq_mask;
 152        grer |= c->irq_edge_rise & c->irq_mask;
 153        gfer |= c->irq_edge_fall & c->irq_mask;
 154        __raw_writel(grer, c->regbase + GRER_OFFSET);
 155        __raw_writel(gfer, c->regbase + GFER_OFFSET);
 156}
 157
 158static int pxa_gpio_irq_type(unsigned int irq, unsigned int type)
 159{
 160        struct pxa_gpio_chip *c;
 161        int gpio = irq_to_gpio(irq);
 162        unsigned long gpdr, mask = GPIO_bit(gpio);
 163
 164        c = gpio_to_chip(gpio);
 165
 166        if (type == IRQ_TYPE_PROBE) {
 167                /* Don't mess with enabled GPIOs using preconfigured edges or
 168                 * GPIOs set to alternate function or to output during probe
 169                 */
 170                if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))
 171                        return 0;
 172
 173                if (__gpio_is_occupied(gpio))
 174                        return 0;
 175
 176                type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
 177        }
 178
 179        gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
 180
 181        if (__gpio_is_inverted(gpio))
 182                __raw_writel(gpdr | mask,  c->regbase + GPDR_OFFSET);
 183        else
 184                __raw_writel(gpdr & ~mask, c->regbase + GPDR_OFFSET);
 185
 186        if (type & IRQ_TYPE_EDGE_RISING)
 187                c->irq_edge_rise |= mask;
 188        else
 189                c->irq_edge_rise &= ~mask;
 190
 191        if (type & IRQ_TYPE_EDGE_FALLING)
 192                c->irq_edge_fall |= mask;
 193        else
 194                c->irq_edge_fall &= ~mask;
 195
 196        update_edge_detect(c);
 197
 198        pr_debug("%s: IRQ%d (GPIO%d) - edge%s%s\n", __func__, irq, gpio,
 199                ((type & IRQ_TYPE_EDGE_RISING)  ? " rising"  : ""),
 200                ((type & IRQ_TYPE_EDGE_FALLING) ? " falling" : ""));
 201        return 0;
 202}
 203
 204static void pxa_gpio_demux_handler(unsigned int irq, struct irq_desc *desc)
 205{
 206        struct pxa_gpio_chip *c;
 207        int loop, gpio, gpio_base, n;
 208        unsigned long gedr;
 209
 210        do {
 211                loop = 0;
 212                for_each_gpio_chip(gpio, c) {
 213                        gpio_base = c->chip.base;
 214
 215                        gedr = __raw_readl(c->regbase + GEDR_OFFSET);
 216                        gedr = gedr & c->irq_mask;
 217                        __raw_writel(gedr, c->regbase + GEDR_OFFSET);
 218
 219                        n = find_first_bit(&gedr, BITS_PER_LONG);
 220                        while (n < BITS_PER_LONG) {
 221                                loop = 1;
 222
 223                                generic_handle_irq(gpio_to_irq(gpio_base + n));
 224                                n = find_next_bit(&gedr, BITS_PER_LONG, n + 1);
 225                        }
 226                }
 227        } while (loop);
 228}
 229
 230static void pxa_ack_muxed_gpio(unsigned int irq)
 231{
 232        int gpio = irq_to_gpio(irq);
 233        struct pxa_gpio_chip *c = gpio_to_chip(gpio);
 234
 235        __raw_writel(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);
 236}
 237
 238static void pxa_mask_muxed_gpio(unsigned int irq)
 239{
 240        int gpio = irq_to_gpio(irq);
 241        struct pxa_gpio_chip *c = gpio_to_chip(gpio);
 242        uint32_t grer, gfer;
 243
 244        c->irq_mask &= ~GPIO_bit(gpio);
 245
 246        grer = __raw_readl(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
 247        gfer = __raw_readl(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
 248        __raw_writel(grer, c->regbase + GRER_OFFSET);
 249        __raw_writel(gfer, c->regbase + GFER_OFFSET);
 250}
 251
 252static void pxa_unmask_muxed_gpio(unsigned int irq)
 253{
 254        int gpio = irq_to_gpio(irq);
 255        struct pxa_gpio_chip *c = gpio_to_chip(gpio);
 256
 257        c->irq_mask |= GPIO_bit(gpio);
 258        update_edge_detect(c);
 259}
 260
 261static struct irq_chip pxa_muxed_gpio_chip = {
 262        .name           = "GPIO",
 263        .ack            = pxa_ack_muxed_gpio,
 264        .mask           = pxa_mask_muxed_gpio,
 265        .unmask         = pxa_unmask_muxed_gpio,
 266        .set_type       = pxa_gpio_irq_type,
 267};
 268
 269void __init pxa_init_gpio(int mux_irq, int start, int end, set_wake_t fn)
 270{
 271        struct pxa_gpio_chip *c;
 272        int gpio, irq;
 273
 274        pxa_last_gpio = end;
 275
 276        /* Initialize GPIO chips */
 277        pxa_init_gpio_chip(end);
 278
 279        /* clear all GPIO edge detects */
 280        for_each_gpio_chip(gpio, c) {
 281                __raw_writel(0, c->regbase + GFER_OFFSET);
 282                __raw_writel(0, c->regbase + GRER_OFFSET);
 283                __raw_writel(~0,c->regbase + GEDR_OFFSET);
 284        }
 285
 286        for (irq  = gpio_to_irq(start); irq <= gpio_to_irq(end); irq++) {
 287                set_irq_chip(irq, &pxa_muxed_gpio_chip);
 288                set_irq_handler(irq, handle_edge_irq);
 289                set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 290        }
 291
 292        /* Install handler for GPIO>=2 edge detect interrupts */
 293        set_irq_chained_handler(mux_irq, pxa_gpio_demux_handler);
 294        pxa_muxed_gpio_chip.set_wake = fn;
 295}
 296
 297#ifdef CONFIG_PM
 298static int pxa_gpio_suspend(struct sys_device *dev, pm_message_t state)
 299{
 300        struct pxa_gpio_chip *c;
 301        int gpio;
 302
 303        for_each_gpio_chip(gpio, c) {
 304                c->saved_gplr = __raw_readl(c->regbase + GPLR_OFFSET);
 305                c->saved_gpdr = __raw_readl(c->regbase + GPDR_OFFSET);
 306                c->saved_grer = __raw_readl(c->regbase + GRER_OFFSET);
 307                c->saved_gfer = __raw_readl(c->regbase + GFER_OFFSET);
 308
 309                /* Clear GPIO transition detect bits */
 310                __raw_writel(0xffffffff, c->regbase + GEDR_OFFSET);
 311        }
 312        return 0;
 313}
 314
 315static int pxa_gpio_resume(struct sys_device *dev)
 316{
 317        struct pxa_gpio_chip *c;
 318        int gpio;
 319
 320        for_each_gpio_chip(gpio, c) {
 321                /* restore level with set/clear */
 322                __raw_writel( c->saved_gplr, c->regbase + GPSR_OFFSET);
 323                __raw_writel(~c->saved_gplr, c->regbase + GPCR_OFFSET);
 324
 325                __raw_writel(c->saved_grer, c->regbase + GRER_OFFSET);
 326                __raw_writel(c->saved_gfer, c->regbase + GFER_OFFSET);
 327                __raw_writel(c->saved_gpdr, c->regbase + GPDR_OFFSET);
 328        }
 329        return 0;
 330}
 331#else
 332#define pxa_gpio_suspend        NULL
 333#define pxa_gpio_resume         NULL
 334#endif
 335
 336struct sysdev_class pxa_gpio_sysclass = {
 337        .name           = "gpio",
 338        .suspend        = pxa_gpio_suspend,
 339        .resume         = pxa_gpio_resume,
 340};
 341
 342static int __init pxa_gpio_init(void)
 343{
 344        return sysdev_class_register(&pxa_gpio_sysclass);
 345}
 346
 347core_initcall(pxa_gpio_init);
 348