drivers/gpio/gpio-timberdale.c

   1 /*
   2  * Timberdale FPGA GPIO driver
   3  * Author: Mocean Laboratories
   4  * Copyright (c) 2009 Intel Corporation
   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  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 /* Supports:
  21  * Timberdale FPGA GPIO
  22  */
  23
  24 #include <linux/init.h>
  25 #include <linux/gpio/driver.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/irq.h>
  28 #include <linux/io.h>
  29 #include <linux/timb_gpio.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/slab.h>
  32
  33 #define DRIVER_NAME "timb-gpio"
  34
  35 #define TGPIOVAL        0x00
  36 #define TGPIODIR        0x04
  37 #define TGPIO_IER       0x08
  38 #define TGPIO_ISR       0x0c
  39 #define TGPIO_IPR       0x10
  40 #define TGPIO_ICR       0x14
  41 #define TGPIO_FLR       0x18
  42 #define TGPIO_LVR       0x1c
  43 #define TGPIO_VER       0x20
  44 #define TGPIO_BFLR      0x24
  45
  46 struct timbgpio {
  47         void __iomem            *membase;
  48         spinlock_t              lock; /* mutual exclusion */
  49         struct gpio_chip        gpio;
  50         int                     irq_base;
  51         unsigned long           last_ier;
  52 };
  53
  54 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
  55         unsigned offset, bool enabled)
  56 {
  57         struct timbgpio *tgpio = gpiochip_get_data(gpio);
  58         u32 reg;
  59
  60         spin_lock(&tgpio->lock);
  61         reg = ioread32(tgpio->membase + offset);
  62
  63         if (enabled)
  64                 reg |= (1 << index);
  65         else
  66                 reg &= ~(1 << index);
  67
  68         iowrite32(reg, tgpio->membase + offset);
  69         spin_unlock(&tgpio->lock);
  70
  71         return 0;
  72 }
  73
  74 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
  75 {
  76         return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
  77 }
  78
  79 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
  80 {
  81         struct timbgpio *tgpio = gpiochip_get_data(gpio);
  82         u32 value;
  83
  84         value = ioread32(tgpio->membase + TGPIOVAL);
  85         return (value & (1 << nr)) ? 1 : 0;
  86 }
  87
  88 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
  89                                                 unsigned nr, int val)
  90 {
  91         return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
  92 }
  93
  94 static void timbgpio_gpio_set(struct gpio_chip *gpio,
  95                                 unsigned nr, int val)
  96 {
  97         timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
  98 }
  99
 100 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
 101 {
 102         struct timbgpio *tgpio = gpiochip_get_data(gpio);
 103
 104         if (tgpio->irq_base <= 0)
 105                 return -EINVAL;
 106
 107         return tgpio->irq_base + offset;
 108 }
 109
 110 /*
 111  * GPIO IRQ
 112  */
 113 static void timbgpio_irq_disable(struct irq_data *d)
 114 {
 115         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 116         int offset = d->irq - tgpio->irq_base;
 117         unsigned long flags;
 118
 119         spin_lock_irqsave(&tgpio->lock, flags);
 120         tgpio->last_ier &= ~(1UL << offset);
 121         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 122         spin_unlock_irqrestore(&tgpio->lock, flags);
 123 }
 124
 125 static void timbgpio_irq_enable(struct irq_data *d)
 126 {
 127         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 128         int offset = d->irq - tgpio->irq_base;
 129         unsigned long flags;
 130
 131         spin_lock_irqsave(&tgpio->lock, flags);
 132         tgpio->last_ier |= 1UL << offset;
 133         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 134         spin_unlock_irqrestore(&tgpio->lock, flags);
 135 }
 136
 137 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger)
 138 {
 139         struct timbgpio *tgpio = irq_data_get_irq_chip_data(d);
 140         int offset = d->irq - tgpio->irq_base;
 141         unsigned long flags;
 142         u32 lvr, flr, bflr = 0;
 143         u32 ver;
 144         int ret = 0;
 145
 146         if (offset < 0 || offset > tgpio->gpio.ngpio)
 147                 return -EINVAL;
 148
 149         ver = ioread32(tgpio->membase + TGPIO_VER);
 150
 151         spin_lock_irqsave(&tgpio->lock, flags);
 152
 153         lvr = ioread32(tgpio->membase + TGPIO_LVR);
 154         flr = ioread32(tgpio->membase + TGPIO_FLR);
 155         if (ver > 2)
 156                 bflr = ioread32(tgpio->membase + TGPIO_BFLR);
 157
 158         if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 159                 bflr &= ~(1 << offset);
 160                 flr &= ~(1 << offset);
 161                 if (trigger & IRQ_TYPE_LEVEL_HIGH)
 162                         lvr |= 1 << offset;
 163                 else
 164                         lvr &= ~(1 << offset);
 165         }
 166
 167         if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 168                 if (ver < 3) {
 169                         ret = -EINVAL;
 170                         goto out;
 171                 } else {
 172                         flr |= 1 << offset;
 173                         bflr |= 1 << offset;
 174                 }
 175         } else {
 176                 bflr &= ~(1 << offset);
 177                 flr |= 1 << offset;
 178                 if (trigger & IRQ_TYPE_EDGE_FALLING)
 179                         lvr &= ~(1 << offset);
 180                 else
 181                         lvr |= 1 << offset;
 182         }
 183
 184         iowrite32(lvr, tgpio->membase + TGPIO_LVR);
 185         iowrite32(flr, tgpio->membase + TGPIO_FLR);
 186         if (ver > 2)
 187                 iowrite32(bflr, tgpio->membase + TGPIO_BFLR);
 188
 189         iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);
 190
 191 out:
 192         spin_unlock_irqrestore(&tgpio->lock, flags);
 193         return ret;
 194 }
 195
 196 static void timbgpio_irq(struct irq_desc *desc)
 197 {
 198         struct timbgpio *tgpio = irq_desc_get_handler_data(desc);
 199         struct irq_data *data = irq_desc_get_irq_data(desc);
 200         unsigned long ipr;
 201         int offset;
 202
 203         data->chip->irq_ack(data);
 204         ipr = ioread32(tgpio->membase + TGPIO_IPR);
 205         iowrite32(ipr, tgpio->membase + TGPIO_ICR);
 206
 207         /*
 208          * Some versions of the hardware trash the IER register if more than
 209          * one interrupt is received simultaneously.
 210          */
 211         iowrite32(0, tgpio->membase + TGPIO_IER);
 212
 213         for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
 214                 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));
 215
 216         iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
 217 }
 218
 219 static struct irq_chip timbgpio_irqchip = {
 220         .name           = "GPIO",
 221         .irq_enable     = timbgpio_irq_enable,
 222         .irq_disable    = timbgpio_irq_disable,
 223         .irq_set_type   = timbgpio_irq_type,
 224 };
 225
 226 static int timbgpio_probe(struct platform_device *pdev)
 227 {
 228         int err, i;
 229         struct device *dev = &pdev->dev;
 230         struct gpio_chip *gc;
 231         struct timbgpio *tgpio;
 232         struct resource *iomem;
 233         struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
 234         int irq = platform_get_irq(pdev, 0);
 235
 236         if (!pdata || pdata->nr_pins > 32) {
 237                 dev_err(dev, "Invalid platform data\n");
 238                 return -EINVAL;
 239         }
 240
 241         tgpio = devm_kzalloc(dev, sizeof(*tgpio), GFP_KERNEL);
 242         if (!tgpio)
 243                 return -EINVAL;
 244
 245         tgpio->irq_base = pdata->irq_base;
 246
 247         spin_lock_init(&tgpio->lock);
 248
 249         iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 250         tgpio->membase = devm_ioremap_resource(dev, iomem);
 251         if (IS_ERR(tgpio->membase))
 252                 return PTR_ERR(tgpio->membase);
 253
 254         gc = &tgpio->gpio;
 255
 256         gc->label = dev_name(&pdev->dev);
 257         gc->owner = THIS_MODULE;
 258         gc->parent = &pdev->dev;
 259         gc->direction_input = timbgpio_gpio_direction_input;
 260         gc->get = timbgpio_gpio_get;
 261         gc->direction_output = timbgpio_gpio_direction_output;
 262         gc->set = timbgpio_gpio_set;
 263         gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
 264         gc->dbg_show = NULL;
 265         gc->base = pdata->gpio_base;
 266         gc->ngpio = pdata->nr_pins;
 267         gc->can_sleep = false;
 268
 269         err = devm_gpiochip_add_data(&pdev->dev, gc, tgpio);
 270         if (err)
 271                 return err;
 272
 273         platform_set_drvdata(pdev, tgpio);
 274
 275         /* make sure to disable interrupts */
 276         iowrite32(0x0, tgpio->membase + TGPIO_IER);
 277
 278         if (irq < 0 || tgpio->irq_base <= 0)
 279                 return 0;
 280
 281         for (i = 0; i < pdata->nr_pins; i++) {
 282                 irq_set_chip_and_handler(tgpio->irq_base + i,
 283                         &timbgpio_irqchip, handle_simple_irq);
 284                 irq_set_chip_data(tgpio->irq_base + i, tgpio);
 285                 irq_clear_status_flags(tgpio->irq_base + i, IRQ_NOREQUEST | IRQ_NOPROBE);
 286         }
 287
 288         irq_set_chained_handler_and_data(irq, timbgpio_irq, tgpio);
 289
 290         return 0;
 291 }
 292
 293 static struct platform_driver timbgpio_platform_driver = {
 294         .driver = {
 295                 .name                   = DRIVER_NAME,
 296                 .suppress_bind_attrs    = true,
 297         },
 298         .probe          = timbgpio_probe,
 299 };
 300
 301 /*--------------------------------------------------------------------------*/
 302
 303 builtin_platform_driver(timbgpio_platform_driver);