drivers/gpio/gpio-sa1100.c

   1 /*
   2  * linux/arch/arm/mach-sa1100/gpio.c
   3  *
   4  * Generic SA-1100 GPIO handling
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/gpio.h>
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/io.h>
  14 #include <linux/syscore_ops.h>
  15 #include <soc/sa1100/pwer.h>
  16 #include <mach/hardware.h>
  17 #include <mach/irqs.h>
  18
  19 struct sa1100_gpio_chip {
  20         struct gpio_chip chip;
  21         void __iomem *membase;
  22         int irqbase;
  23         u32 irqmask;
  24         u32 irqrising;
  25         u32 irqfalling;
  26         u32 irqwake;
  27 };
  28
  29 #define sa1100_gpio_chip(x) container_of(x, struct sa1100_gpio_chip, chip)
  30
  31 enum {
  32         R_GPLR = 0x00,
  33         R_GPDR = 0x04,
  34         R_GPSR = 0x08,
  35         R_GPCR = 0x0c,
  36         R_GRER = 0x10,
  37         R_GFER = 0x14,
  38         R_GEDR = 0x18,
  39         R_GAFR = 0x1c,
  40 };
  41
  42 static int sa1100_gpio_get(struct gpio_chip *chip, unsigned offset)
  43 {
  44         return readl_relaxed(sa1100_gpio_chip(chip)->membase + R_GPLR) &
  45                 BIT(offset);
  46 }
  47
  48 static void sa1100_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
  49 {
  50         int reg = value ? R_GPSR : R_GPCR;
  51
  52         writel_relaxed(BIT(offset), sa1100_gpio_chip(chip)->membase + reg);
  53 }
  54
  55 static int sa1100_get_direction(struct gpio_chip *chip, unsigned offset)
  56 {
  57         void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
  58
  59         return !(readl_relaxed(gpdr) & BIT(offset));
  60 }
  61
  62 static int sa1100_direction_input(struct gpio_chip *chip, unsigned offset)
  63 {
  64         void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
  65         unsigned long flags;
  66
  67         local_irq_save(flags);
  68         writel_relaxed(readl_relaxed(gpdr) & ~BIT(offset), gpdr);
  69         local_irq_restore(flags);
  70
  71         return 0;
  72 }
  73
  74 static int sa1100_direction_output(struct gpio_chip *chip, unsigned offset, int value)
  75 {
  76         void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
  77         unsigned long flags;
  78
  79         local_irq_save(flags);
  80         sa1100_gpio_set(chip, offset, value);
  81         writel_relaxed(readl_relaxed(gpdr) | BIT(offset), gpdr);
  82         local_irq_restore(flags);
  83
  84         return 0;
  85 }
  86
  87 static int sa1100_to_irq(struct gpio_chip *chip, unsigned offset)
  88 {
  89         return sa1100_gpio_chip(chip)->irqbase + offset;
  90 }
  91
  92 static struct sa1100_gpio_chip sa1100_gpio_chip = {
  93         .chip = {
  94                 .label                  = "gpio",
  95                 .get_direction          = sa1100_get_direction,
  96                 .direction_input        = sa1100_direction_input,
  97                 .direction_output       = sa1100_direction_output,
  98                 .set                    = sa1100_gpio_set,
  99                 .get                    = sa1100_gpio_get,
 100                 .to_irq                 = sa1100_to_irq,
 101                 .base                   = 0,
 102                 .ngpio                  = GPIO_MAX + 1,
 103         },
 104         .membase = (void *)&GPLR,
 105         .irqbase = IRQ_GPIO0,
 106 };
 107
 108 /*
 109  * SA1100 GPIO edge detection for IRQs:
 110  * IRQs are generated on Falling-Edge, Rising-Edge, or both.
 111  * Use this instead of directly setting GRER/GFER.
 112  */
 113 static void sa1100_update_edge_regs(struct sa1100_gpio_chip *sgc)
 114 {
 115         void *base = sgc->membase;
 116         u32 grer, gfer;
 117
 118         grer = sgc->irqrising & sgc->irqmask;
 119         gfer = sgc->irqfalling & sgc->irqmask;
 120
 121         writel_relaxed(grer, base + R_GRER);
 122         writel_relaxed(gfer, base + R_GFER);
 123 }
 124
 125 static int sa1100_gpio_type(struct irq_data *d, unsigned int type)
 126 {
 127         struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
 128         unsigned int mask = BIT(d->hwirq);
 129
 130         if (type == IRQ_TYPE_PROBE) {
 131                 if ((sgc->irqrising | sgc->irqfalling) & mask)
 132                         return 0;
 133                 type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
 134         }
 135
 136         if (type & IRQ_TYPE_EDGE_RISING)
 137                 sgc->irqrising |= mask;
 138         else
 139                 sgc->irqrising &= ~mask;
 140         if (type & IRQ_TYPE_EDGE_FALLING)
 141                 sgc->irqfalling |= mask;
 142         else
 143                 sgc->irqfalling &= ~mask;
 144
 145         sa1100_update_edge_regs(sgc);
 146
 147         return 0;
 148 }
 149
 150 /*
 151  * GPIO IRQs must be acknowledged.
 152  */
 153 static void sa1100_gpio_ack(struct irq_data *d)
 154 {
 155         struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
 156
 157         writel_relaxed(BIT(d->hwirq), sgc->membase + R_GEDR);
 158 }
 159
 160 static void sa1100_gpio_mask(struct irq_data *d)
 161 {
 162         struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
 163         unsigned int mask = BIT(d->hwirq);
 164
 165         sgc->irqmask &= ~mask;
 166
 167         sa1100_update_edge_regs(sgc);
 168 }
 169
 170 static void sa1100_gpio_unmask(struct irq_data *d)
 171 {
 172         struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
 173         unsigned int mask = BIT(d->hwirq);
 174
 175         sgc->irqmask |= mask;
 176
 177         sa1100_update_edge_regs(sgc);
 178 }
 179
 180 static int sa1100_gpio_wake(struct irq_data *d, unsigned int on)
 181 {
 182         struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
 183         int ret = sa11x0_gpio_set_wake(d->hwirq, on);
 184         if (!ret) {
 185                 if (on)
 186                         sgc->irqwake |= BIT(d->hwirq);
 187                 else
 188                         sgc->irqwake &= ~BIT(d->hwirq);
 189         }
 190         return ret;
 191 }
 192
 193 /*
 194  * This is for GPIO IRQs
 195  */
 196 static struct irq_chip sa1100_gpio_irq_chip = {
 197         .name           = "GPIO",
 198         .irq_ack        = sa1100_gpio_ack,
 199         .irq_mask       = sa1100_gpio_mask,
 200         .irq_unmask     = sa1100_gpio_unmask,
 201         .irq_set_type   = sa1100_gpio_type,
 202         .irq_set_wake   = sa1100_gpio_wake,
 203 };
 204
 205 static int sa1100_gpio_irqdomain_map(struct irq_domain *d,
 206                 unsigned int irq, irq_hw_number_t hwirq)
 207 {
 208         struct sa1100_gpio_chip *sgc = d->host_data;
 209
 210         irq_set_chip_data(irq, sgc);
 211         irq_set_chip_and_handler(irq, &sa1100_gpio_irq_chip, handle_edge_irq);
 212         irq_set_probe(irq);
 213
 214         return 0;
 215 }
 216
 217 static const struct irq_domain_ops sa1100_gpio_irqdomain_ops = {
 218         .map = sa1100_gpio_irqdomain_map,
 219         .xlate = irq_domain_xlate_onetwocell,
 220 };
 221
 222 static struct irq_domain *sa1100_gpio_irqdomain;
 223
 224 /*
 225  * IRQ 0-11 (GPIO) handler.  We enter here with the
 226  * irq_controller_lock held, and IRQs disabled.  Decode the IRQ
 227  * and call the handler.
 228  */
 229 static void sa1100_gpio_handler(struct irq_desc *desc)
 230 {
 231         struct sa1100_gpio_chip *sgc = irq_desc_get_handler_data(desc);
 232         unsigned int irq, mask;
 233         void __iomem *gedr = sgc->membase + R_GEDR;
 234
 235         mask = readl_relaxed(gedr);
 236         do {
 237                 /*
 238                  * clear down all currently active IRQ sources.
 239                  * We will be processing them all.
 240                  */
 241                 writel_relaxed(mask, gedr);
 242
 243                 irq = sgc->irqbase;
 244                 do {
 245                         if (mask & 1)
 246                                 generic_handle_irq(irq);
 247                         mask >>= 1;
 248                         irq++;
 249                 } while (mask);
 250
 251                 mask = readl_relaxed(gedr);
 252         } while (mask);
 253 }
 254
 255 static int sa1100_gpio_suspend(void)
 256 {
 257         struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
 258
 259         /*
 260          * Set the appropriate edges for wakeup.
 261          */
 262         writel_relaxed(sgc->irqwake & sgc->irqrising, sgc->membase + R_GRER);
 263         writel_relaxed(sgc->irqwake & sgc->irqfalling, sgc->membase + R_GFER);
 264
 265         /*
 266          * Clear any pending GPIO interrupts.
 267          */
 268         writel_relaxed(readl_relaxed(sgc->membase + R_GEDR),
 269                        sgc->membase + R_GEDR);
 270
 271         return 0;
 272 }
 273
 274 static void sa1100_gpio_resume(void)
 275 {
 276         sa1100_update_edge_regs(&sa1100_gpio_chip);
 277 }
 278
 279 static struct syscore_ops sa1100_gpio_syscore_ops = {
 280         .suspend        = sa1100_gpio_suspend,
 281         .resume         = sa1100_gpio_resume,
 282 };
 283
 284 static int __init sa1100_gpio_init_devicefs(void)
 285 {
 286         register_syscore_ops(&sa1100_gpio_syscore_ops);
 287         return 0;
 288 }
 289
 290 device_initcall(sa1100_gpio_init_devicefs);
 291
 292 static const int sa1100_gpio_irqs[] __initconst = {
 293         /* Install handlers for GPIO 0-10 edge detect interrupts */
 294         IRQ_GPIO0_SC,
 295         IRQ_GPIO1_SC,
 296         IRQ_GPIO2_SC,
 297         IRQ_GPIO3_SC,
 298         IRQ_GPIO4_SC,
 299         IRQ_GPIO5_SC,
 300         IRQ_GPIO6_SC,
 301         IRQ_GPIO7_SC,
 302         IRQ_GPIO8_SC,
 303         IRQ_GPIO9_SC,
 304         IRQ_GPIO10_SC,
 305         /* Install handler for GPIO 11-27 edge detect interrupts */
 306         IRQ_GPIO11_27,
 307 };
 308
 309 void __init sa1100_init_gpio(void)
 310 {
 311         struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
 312         int i;
 313
 314         /* clear all GPIO edge detects */
 315         writel_relaxed(0, sgc->membase + R_GFER);
 316         writel_relaxed(0, sgc->membase + R_GRER);
 317         writel_relaxed(-1, sgc->membase + R_GEDR);
 318
 319         gpiochip_add_data(&sa1100_gpio_chip.chip, NULL);
 320
 321         sa1100_gpio_irqdomain = irq_domain_add_simple(NULL,
 322                         28, IRQ_GPIO0,
 323                         &sa1100_gpio_irqdomain_ops, sgc);
 324
 325         for (i = 0; i < ARRAY_SIZE(sa1100_gpio_irqs); i++)
 326                 irq_set_chained_handler_and_data(sa1100_gpio_irqs[i],
 327                                                  sa1100_gpio_handler, sgc);
 328 }