drivers/gpio/gpio-tb10x.c

   1 /* Abilis Systems MODULE DESCRIPTION
   2  *
   3  * Copyright (C) Abilis Systems 2013
   4  *
   5  * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
   6  *          Christian Ruppert <christian.ruppert@abilis.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/gpio.h>
  26 #include <linux/slab.h>
  27 #include <linux/irq.h>
  28 #include <linux/irqdomain.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/io.h>
  31 #include <linux/of.h>
  32 #include <linux/of_platform.h>
  33 #include <linux/of_gpio.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/bitops.h>
  36 #include <linux/pinctrl/consumer.h>
  37
  38 #define TB10X_GPIO_DIR_IN       (0x00000000)
  39 #define TB10X_GPIO_DIR_OUT      (0x00000001)
  40 #define OFFSET_TO_REG_DDR       (0x00)
  41 #define OFFSET_TO_REG_DATA      (0x04)
  42 #define OFFSET_TO_REG_INT_EN    (0x08)
  43 #define OFFSET_TO_REG_CHANGE    (0x0C)
  44 #define OFFSET_TO_REG_WRMASK    (0x10)
  45 #define OFFSET_TO_REG_INT_TYPE  (0x14)
  46
  47
  48 /**
  49  * @spinlock: used for atomic read/modify/write of registers
  50  * @base: register base address
  51  * @domain: IRQ domain of GPIO generated interrupts managed by this controller
  52  * @irq: Interrupt line of parent interrupt controller
  53  * @gc: gpio_chip structure associated to this GPIO controller
  54  */
  55 struct tb10x_gpio {
  56         spinlock_t spinlock;
  57         void __iomem *base;
  58         struct irq_domain *domain;
  59         int irq;
  60         struct gpio_chip gc;
  61 };
  62
  63 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
  64 {
  65         return ioread32(gpio->base + offs);
  66 }
  67
  68 static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
  69                                 u32 val)
  70 {
  71         iowrite32(val, gpio->base + offs);
  72 }
  73
  74 static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
  75                                 u32 mask, u32 val)
  76 {
  77         u32 r;
  78         unsigned long flags;
  79
  80         spin_lock_irqsave(&gpio->spinlock, flags);
  81
  82         r = tb10x_reg_read(gpio, offs);
  83         r = (r & ~mask) | (val & mask);
  84
  85         tb10x_reg_write(gpio, offs, r);
  86
  87         spin_unlock_irqrestore(&gpio->spinlock, flags);
  88 }
  89
  90 static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  91 {
  92         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
  93         int mask = BIT(offset);
  94         int val = TB10X_GPIO_DIR_IN << offset;
  95
  96         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
  97
  98         return 0;
  99 }
 100
 101 static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
 102 {
 103         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
 104         int val;
 105
 106         val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
 107
 108         if (val & BIT(offset))
 109                 return 1;
 110         else
 111                 return 0;
 112 }
 113
 114 static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 115 {
 116         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
 117         int mask = BIT(offset);
 118         int val = value << offset;
 119
 120         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
 121 }
 122
 123 static int tb10x_gpio_direction_out(struct gpio_chip *chip,
 124                                         unsigned offset, int value)
 125 {
 126         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
 127         int mask = BIT(offset);
 128         int val = TB10X_GPIO_DIR_OUT << offset;
 129
 130         tb10x_gpio_set(chip, offset, value);
 131         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
 132
 133         return 0;
 134 }
 135
 136 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 137 {
 138         struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
 139
 140         return irq_create_mapping(tb10x_gpio->domain, offset);
 141 }
 142
 143 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 144 {
 145         if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
 146                 pr_err("Only (both) edge triggered interrupts supported.\n");
 147                 return -EINVAL;
 148         }
 149
 150         irqd_set_trigger_type(data, type);
 151
 152         return IRQ_SET_MASK_OK;
 153 }
 154
 155 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
 156 {
 157         struct tb10x_gpio *tb10x_gpio = data;
 158         u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
 159         u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
 160         const unsigned long bits = r & m;
 161         int i;
 162
 163         for_each_set_bit(i, &bits, 32)
 164                 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
 165
 166         return IRQ_HANDLED;
 167 }
 168
 169 static int tb10x_gpio_probe(struct platform_device *pdev)
 170 {
 171         struct tb10x_gpio *tb10x_gpio;
 172         struct resource *mem;
 173         struct device_node *dn = pdev->dev.of_node;
 174         int ret = -EBUSY;
 175         u32 ngpio;
 176
 177         if (!dn)
 178                 return -EINVAL;
 179
 180         if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
 181                 return -EINVAL;
 182
 183         tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
 184         if (tb10x_gpio == NULL)
 185                 return -ENOMEM;
 186
 187         spin_lock_init(&tb10x_gpio->spinlock);
 188
 189         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 190         tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
 191         if (IS_ERR(tb10x_gpio->base))
 192                 return PTR_ERR(tb10x_gpio->base);
 193
 194         tb10x_gpio->gc.label            = of_node_full_name(dn);
 195         tb10x_gpio->gc.parent           = &pdev->dev;
 196         tb10x_gpio->gc.owner            = THIS_MODULE;
 197         tb10x_gpio->gc.direction_input  = tb10x_gpio_direction_in;
 198         tb10x_gpio->gc.get              = tb10x_gpio_get;
 199         tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out;
 200         tb10x_gpio->gc.set              = tb10x_gpio_set;
 201         tb10x_gpio->gc.request          = gpiochip_generic_request;
 202         tb10x_gpio->gc.free             = gpiochip_generic_free;
 203         tb10x_gpio->gc.base             = -1;
 204         tb10x_gpio->gc.ngpio            = ngpio;
 205         tb10x_gpio->gc.can_sleep        = false;
 206
 207
 208         ret = devm_gpiochip_add_data(&pdev->dev, &tb10x_gpio->gc, tb10x_gpio);
 209         if (ret < 0) {
 210                 dev_err(&pdev->dev, "Could not add gpiochip.\n");
 211                 return ret;
 212         }
 213
 214         platform_set_drvdata(pdev, tb10x_gpio);
 215
 216         if (of_find_property(dn, "interrupt-controller", NULL)) {
 217                 struct irq_chip_generic *gc;
 218
 219                 ret = platform_get_irq(pdev, 0);
 220                 if (ret < 0) {
 221                         dev_err(&pdev->dev, "No interrupt specified.\n");
 222                         return ret;
 223                 }
 224
 225                 tb10x_gpio->gc.to_irq   = tb10x_gpio_to_irq;
 226                 tb10x_gpio->irq         = ret;
 227
 228                 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
 229                                 IRQF_TRIGGER_NONE | IRQF_SHARED,
 230                                 dev_name(&pdev->dev), tb10x_gpio);
 231                 if (ret != 0)
 232                         return ret;
 233
 234                 tb10x_gpio->domain = irq_domain_add_linear(dn,
 235                                                 tb10x_gpio->gc.ngpio,
 236                                                 &irq_generic_chip_ops, NULL);
 237                 if (!tb10x_gpio->domain) {
 238                         return -ENOMEM;
 239                 }
 240
 241                 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
 242                                 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
 243                                 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
 244                                 IRQ_GC_INIT_MASK_CACHE);
 245                 if (ret)
 246                         return ret;
 247
 248                 gc = tb10x_gpio->domain->gc->gc[0];
 249                 gc->reg_base                         = tb10x_gpio->base;
 250                 gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
 251                 gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
 252                 gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
 253                 gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
 254                 gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
 255                 gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
 256                 gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int tb10x_gpio_remove(struct platform_device *pdev)
 263 {
 264         struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
 265
 266         if (tb10x_gpio->gc.to_irq) {
 267                 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
 268                                         BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
 269                 kfree(tb10x_gpio->domain->gc);
 270                 irq_domain_remove(tb10x_gpio->domain);
 271         }
 272
 273         return 0;
 274 }
 275
 276 static const struct of_device_id tb10x_gpio_dt_ids[] = {
 277         { .compatible = "abilis,tb10x-gpio" },
 278         { }
 279 };
 280 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
 281
 282 static struct platform_driver tb10x_gpio_driver = {
 283         .probe          = tb10x_gpio_probe,
 284         .remove         = tb10x_gpio_remove,
 285         .driver = {
 286                 .name   = "tb10x-gpio",
 287                 .of_match_table = tb10x_gpio_dt_ids,
 288         }
 289 };
 290
 291 module_platform_driver(tb10x_gpio_driver);
 292 MODULE_LICENSE("GPL");
 293 MODULE_DESCRIPTION("tb10x gpio.");
 294 MODULE_VERSION("0.0.1");