kernel/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 inline struct tb10x_gpio *to_tb10x_gpio(struct gpio_chip *chip)
  91 {
  92         return container_of(chip, struct tb10x_gpio, gc);
  93 }
  94
  95 static int tb10x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
  96 {
  97         struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
  98         int mask = BIT(offset);
  99         int val = TB10X_GPIO_DIR_IN << offset;
 100
 101         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
 102
 103         return 0;
 104 }
 105
 106 static int tb10x_gpio_get(struct gpio_chip *chip, unsigned offset)
 107 {
 108         struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
 109         int val;
 110
 111         val = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_DATA);
 112
 113         if (val & BIT(offset))
 114                 return 1;
 115         else
 116                 return 0;
 117 }
 118
 119 static void tb10x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 120 {
 121         struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
 122         int mask = BIT(offset);
 123         int val = value << offset;
 124
 125         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DATA, mask, val);
 126 }
 127
 128 static int tb10x_gpio_direction_out(struct gpio_chip *chip,
 129                                         unsigned offset, int value)
 130 {
 131         struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
 132         int mask = BIT(offset);
 133         int val = TB10X_GPIO_DIR_OUT << offset;
 134
 135         tb10x_gpio_set(chip, offset, value);
 136         tb10x_set_bits(tb10x_gpio, OFFSET_TO_REG_DDR, mask, val);
 137
 138         return 0;
 139 }
 140
 141 static int tb10x_gpio_request(struct gpio_chip *chip, unsigned offset)
 142 {
 143         return pinctrl_request_gpio(chip->base + offset);
 144 }
 145
 146 static void tb10x_gpio_free(struct gpio_chip *chip, unsigned offset)
 147 {
 148         pinctrl_free_gpio(chip->base + offset);
 149 }
 150
 151 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 152 {
 153         struct tb10x_gpio *tb10x_gpio = to_tb10x_gpio(chip);
 154
 155         return irq_create_mapping(tb10x_gpio->domain, offset);
 156 }
 157
 158 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 159 {
 160         if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
 161                 pr_err("Only (both) edge triggered interrupts supported.\n");
 162                 return -EINVAL;
 163         }
 164
 165         irqd_set_trigger_type(data, type);
 166
 167         return IRQ_SET_MASK_OK;
 168 }
 169
 170 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
 171 {
 172         struct tb10x_gpio *tb10x_gpio = data;
 173         u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
 174         u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
 175         const unsigned long bits = r & m;
 176         int i;
 177
 178         for_each_set_bit(i, &bits, 32)
 179                 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
 180
 181         return IRQ_HANDLED;
 182 }
 183
 184 static int tb10x_gpio_probe(struct platform_device *pdev)
 185 {
 186         struct tb10x_gpio *tb10x_gpio;
 187         struct resource *mem;
 188         struct device_node *dn = pdev->dev.of_node;
 189         int ret = -EBUSY;
 190         u32 ngpio;
 191
 192         if (!dn)
 193                 return -EINVAL;
 194
 195         if (of_property_read_u32(dn, "abilis,ngpio", &ngpio))
 196                 return -EINVAL;
 197
 198         tb10x_gpio = devm_kzalloc(&pdev->dev, sizeof(*tb10x_gpio), GFP_KERNEL);
 199         if (tb10x_gpio == NULL)
 200                 return -ENOMEM;
 201
 202         spin_lock_init(&tb10x_gpio->spinlock);
 203
 204         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 205         tb10x_gpio->base = devm_ioremap_resource(&pdev->dev, mem);
 206         if (IS_ERR(tb10x_gpio->base))
 207                 return PTR_ERR(tb10x_gpio->base);
 208
 209         tb10x_gpio->gc.label            = of_node_full_name(dn);
 210         tb10x_gpio->gc.dev              = &pdev->dev;
 211         tb10x_gpio->gc.owner            = THIS_MODULE;
 212         tb10x_gpio->gc.direction_input  = tb10x_gpio_direction_in;
 213         tb10x_gpio->gc.get              = tb10x_gpio_get;
 214         tb10x_gpio->gc.direction_output = tb10x_gpio_direction_out;
 215         tb10x_gpio->gc.set              = tb10x_gpio_set;
 216         tb10x_gpio->gc.request          = tb10x_gpio_request;
 217         tb10x_gpio->gc.free             = tb10x_gpio_free;
 218         tb10x_gpio->gc.base             = -1;
 219         tb10x_gpio->gc.ngpio            = ngpio;
 220         tb10x_gpio->gc.can_sleep        = false;
 221
 222
 223         ret = gpiochip_add(&tb10x_gpio->gc);
 224         if (ret < 0) {
 225                 dev_err(&pdev->dev, "Could not add gpiochip.\n");
 226                 goto fail_gpiochip_registration;
 227         }
 228
 229         platform_set_drvdata(pdev, tb10x_gpio);
 230
 231         if (of_find_property(dn, "interrupt-controller", NULL)) {
 232                 struct irq_chip_generic *gc;
 233
 234                 ret = platform_get_irq(pdev, 0);
 235                 if (ret < 0) {
 236                         dev_err(&pdev->dev, "No interrupt specified.\n");
 237                         goto fail_get_irq;
 238                 }
 239
 240                 tb10x_gpio->gc.to_irq   = tb10x_gpio_to_irq;
 241                 tb10x_gpio->irq         = ret;
 242
 243                 ret = devm_request_irq(&pdev->dev, ret, tb10x_gpio_irq_cascade,
 244                                 IRQF_TRIGGER_NONE | IRQF_SHARED,
 245                                 dev_name(&pdev->dev), tb10x_gpio);
 246                 if (ret != 0)
 247                         goto fail_request_irq;
 248
 249                 tb10x_gpio->domain = irq_domain_add_linear(dn,
 250                                                 tb10x_gpio->gc.ngpio,
 251                                                 &irq_generic_chip_ops, NULL);
 252                 if (!tb10x_gpio->domain) {
 253                         ret = -ENOMEM;
 254                         goto fail_irq_domain;
 255                 }
 256
 257                 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
 258                                 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
 259                                 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
 260                                 IRQ_GC_INIT_MASK_CACHE);
 261                 if (ret)
 262                         goto fail_irq_domain;
 263
 264                 gc = tb10x_gpio->domain->gc->gc[0];
 265                 gc->reg_base                         = tb10x_gpio->base;
 266                 gc->chip_types[0].type               = IRQ_TYPE_EDGE_BOTH;
 267                 gc->chip_types[0].chip.irq_ack       = irq_gc_ack_set_bit;
 268                 gc->chip_types[0].chip.irq_mask      = irq_gc_mask_clr_bit;
 269                 gc->chip_types[0].chip.irq_unmask    = irq_gc_mask_set_bit;
 270                 gc->chip_types[0].chip.irq_set_type  = tb10x_gpio_irq_set_type;
 271                 gc->chip_types[0].regs.ack           = OFFSET_TO_REG_CHANGE;
 272                 gc->chip_types[0].regs.mask          = OFFSET_TO_REG_INT_EN;
 273         }
 274
 275         return 0;
 276
 277 fail_irq_domain:
 278 fail_request_irq:
 279 fail_get_irq:
 280         gpiochip_remove(&tb10x_gpio->gc);
 281 fail_gpiochip_registration:
 282 fail_ioremap:
 283         return ret;
 284 }
 285
 286 static int tb10x_gpio_remove(struct platform_device *pdev)
 287 {
 288         struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
 289
 290         if (tb10x_gpio->gc.to_irq) {
 291                 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
 292                                         BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
 293                 kfree(tb10x_gpio->domain->gc);
 294                 irq_domain_remove(tb10x_gpio->domain);
 295                 free_irq(tb10x_gpio->irq, tb10x_gpio);
 296         }
 297         gpiochip_remove(&tb10x_gpio->gc);
 298
 299         return 0;
 300 }
 301
 302 static const struct of_device_id tb10x_gpio_dt_ids[] = {
 303         { .compatible = "abilis,tb10x-gpio" },
 304         { }
 305 };
 306 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
 307
 308 static struct platform_driver tb10x_gpio_driver = {
 309         .probe          = tb10x_gpio_probe,
 310         .remove         = tb10x_gpio_remove,
 311         .driver = {
 312                 .name   = "tb10x-gpio",
 313                 .of_match_table = tb10x_gpio_dt_ids,
 314         }
 315 };
 316
 317 module_platform_driver(tb10x_gpio_driver);
 318 MODULE_LICENSE("GPL");
 319 MODULE_DESCRIPTION("tb10x gpio.");
 320 MODULE_VERSION("0.0.1");