drivers/gpio/gpio-tc3589x.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  *
   4  * License Terms: GNU General Public License, version 2
   5  * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
   6  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13 #include <linux/gpio.h>
  14 #include <linux/of.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/mfd/tc3589x.h>
  17
  18 /*
  19  * These registers are modified under the irq bus lock and cached to avoid
  20  * unnecessary writes in bus_sync_unlock.
  21  */
  22 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
  23
  24 #define CACHE_NR_REGS   4
  25 #define CACHE_NR_BANKS  3
  26
  27 struct tc3589x_gpio {
  28         struct gpio_chip chip;
  29         struct tc3589x *tc3589x;
  30         struct device *dev;
  31         struct mutex irq_lock;
  32         /* Caches of interrupt control registers for bus_lock */
  33         u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
  34         u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
  35 };
  36
  37 static inline struct tc3589x_gpio *to_tc3589x_gpio(struct gpio_chip *chip)
  38 {
  39         return container_of(chip, struct tc3589x_gpio, chip);
  40 }
  41
  42 static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned offset)
  43 {
  44         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
  45         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  46         u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
  47         u8 mask = 1 << (offset % 8);
  48         int ret;
  49
  50         ret = tc3589x_reg_read(tc3589x, reg);
  51         if (ret < 0)
  52                 return ret;
  53
  54         return ret & mask;
  55 }
  56
  57 static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
  58 {
  59         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
  60         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  61         u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
  62         unsigned pos = offset % 8;
  63         u8 data[] = {!!val << pos, 1 << pos};
  64
  65         tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
  66 }
  67
  68 static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
  69                                          unsigned offset, int val)
  70 {
  71         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
  72         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  73         u8 reg = TC3589x_GPIODIR0 + offset / 8;
  74         unsigned pos = offset % 8;
  75
  76         tc3589x_gpio_set(chip, offset, val);
  77
  78         return tc3589x_set_bits(tc3589x, reg, 1 << pos, 1 << pos);
  79 }
  80
  81 static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
  82                                         unsigned offset)
  83 {
  84         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
  85         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
  86         u8 reg = TC3589x_GPIODIR0 + offset / 8;
  87         unsigned pos = offset % 8;
  88
  89         return tc3589x_set_bits(tc3589x, reg, 1 << pos, 0);
  90 }
  91
  92 static struct gpio_chip template_chip = {
  93         .label                  = "tc3589x",
  94         .owner                  = THIS_MODULE,
  95         .direction_input        = tc3589x_gpio_direction_input,
  96         .get                    = tc3589x_gpio_get,
  97         .direction_output       = tc3589x_gpio_direction_output,
  98         .set                    = tc3589x_gpio_set,
  99         .can_sleep              = true,
 100 };
 101
 102 static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 103 {
 104         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 105         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(gc);
 106         int offset = d->hwirq;
 107         int regoffset = offset / 8;
 108         int mask = 1 << (offset % 8);
 109
 110         if (type == IRQ_TYPE_EDGE_BOTH) {
 111                 tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
 112                 return 0;
 113         }
 114
 115         tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;
 116
 117         if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
 118                 tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
 119         else
 120                 tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;
 121
 122         if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
 123                 tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
 124         else
 125                 tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;
 126
 127         return 0;
 128 }
 129
 130 static void tc3589x_gpio_irq_lock(struct irq_data *d)
 131 {
 132         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 133         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(gc);
 134
 135         mutex_lock(&tc3589x_gpio->irq_lock);
 136 }
 137
 138 static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
 139 {
 140         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 141         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(gc);
 142         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
 143         static const u8 regmap[] = {
 144                 [REG_IBE]       = TC3589x_GPIOIBE0,
 145                 [REG_IEV]       = TC3589x_GPIOIEV0,
 146                 [REG_IS]        = TC3589x_GPIOIS0,
 147                 [REG_IE]        = TC3589x_GPIOIE0,
 148         };
 149         int i, j;
 150
 151         for (i = 0; i < CACHE_NR_REGS; i++) {
 152                 for (j = 0; j < CACHE_NR_BANKS; j++) {
 153                         u8 old = tc3589x_gpio->oldregs[i][j];
 154                         u8 new = tc3589x_gpio->regs[i][j];
 155
 156                         if (new == old)
 157                                 continue;
 158
 159                         tc3589x_gpio->oldregs[i][j] = new;
 160                         tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
 161                 }
 162         }
 163
 164         mutex_unlock(&tc3589x_gpio->irq_lock);
 165 }
 166
 167 static void tc3589x_gpio_irq_mask(struct irq_data *d)
 168 {
 169         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 170         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(gc);
 171         int offset = d->hwirq;
 172         int regoffset = offset / 8;
 173         int mask = 1 << (offset % 8);
 174
 175         tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
 176 }
 177
 178 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
 179 {
 180         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 181         struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(gc);
 182         int offset = d->hwirq;
 183         int regoffset = offset / 8;
 184         int mask = 1 << (offset % 8);
 185
 186         tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
 187 }
 188
 189 static struct irq_chip tc3589x_gpio_irq_chip = {
 190         .name                   = "tc3589x-gpio",
 191         .irq_bus_lock           = tc3589x_gpio_irq_lock,
 192         .irq_bus_sync_unlock    = tc3589x_gpio_irq_sync_unlock,
 193         .irq_mask               = tc3589x_gpio_irq_mask,
 194         .irq_unmask             = tc3589x_gpio_irq_unmask,
 195         .irq_set_type           = tc3589x_gpio_irq_set_type,
 196 };
 197
 198 static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
 199 {
 200         struct tc3589x_gpio *tc3589x_gpio = dev;
 201         struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
 202         u8 status[CACHE_NR_BANKS];
 203         int ret;
 204         int i;
 205
 206         ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
 207                                  ARRAY_SIZE(status), status);
 208         if (ret < 0)
 209                 return IRQ_NONE;
 210
 211         for (i = 0; i < ARRAY_SIZE(status); i++) {
 212                 unsigned int stat = status[i];
 213                 if (!stat)
 214                         continue;
 215
 216                 while (stat) {
 217                         int bit = __ffs(stat);
 218                         int line = i * 8 + bit;
 219                         int irq = irq_find_mapping(tc3589x_gpio->chip.irqdomain,
 220                                                    line);
 221
 222                         handle_nested_irq(irq);
 223                         stat &= ~(1 << bit);
 224                 }
 225
 226                 tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
 227         }
 228
 229         return IRQ_HANDLED;
 230 }
 231
 232 static int tc3589x_gpio_probe(struct platform_device *pdev)
 233 {
 234         struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
 235         struct device_node *np = pdev->dev.of_node;
 236         struct tc3589x_gpio *tc3589x_gpio;
 237         int ret;
 238         int irq;
 239
 240         if (!np) {
 241                 dev_err(&pdev->dev, "No Device Tree node found\n");
 242                 return -EINVAL;
 243         }
 244
 245         irq = platform_get_irq(pdev, 0);
 246         if (irq < 0)
 247                 return irq;
 248
 249         tc3589x_gpio = devm_kzalloc(&pdev->dev, sizeof(struct tc3589x_gpio),
 250                                     GFP_KERNEL);
 251         if (!tc3589x_gpio)
 252                 return -ENOMEM;
 253
 254         mutex_init(&tc3589x_gpio->irq_lock);
 255
 256         tc3589x_gpio->dev = &pdev->dev;
 257         tc3589x_gpio->tc3589x = tc3589x;
 258
 259         tc3589x_gpio->chip = template_chip;
 260         tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
 261         tc3589x_gpio->chip.dev = &pdev->dev;
 262         tc3589x_gpio->chip.base = -1;
 263         tc3589x_gpio->chip.of_node = np;
 264
 265         /* Bring the GPIO module out of reset */
 266         ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
 267                                TC3589x_RSTCTRL_GPIRST, 0);
 268         if (ret < 0)
 269                 return ret;
 270
 271         ret = devm_request_threaded_irq(&pdev->dev,
 272                                         irq, NULL, tc3589x_gpio_irq,
 273                                         IRQF_ONESHOT, "tc3589x-gpio",
 274                                         tc3589x_gpio);
 275         if (ret) {
 276                 dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
 277                 return ret;
 278         }
 279
 280         ret = gpiochip_add(&tc3589x_gpio->chip);
 281         if (ret) {
 282                 dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
 283                 return ret;
 284         }
 285
 286         ret =  gpiochip_irqchip_add(&tc3589x_gpio->chip,
 287                                     &tc3589x_gpio_irq_chip,
 288                                     0,
 289                                     handle_simple_irq,
 290                                     IRQ_TYPE_NONE);
 291         if (ret) {
 292                 dev_err(&pdev->dev,
 293                         "could not connect irqchip to gpiochip\n");
 294                 return ret;
 295         }
 296
 297         gpiochip_set_chained_irqchip(&tc3589x_gpio->chip,
 298                                      &tc3589x_gpio_irq_chip,
 299                                      irq,
 300                                      NULL);
 301
 302         platform_set_drvdata(pdev, tc3589x_gpio);
 303
 304         return 0;
 305 }
 306
 307 static int tc3589x_gpio_remove(struct platform_device *pdev)
 308 {
 309         struct tc3589x_gpio *tc3589x_gpio = platform_get_drvdata(pdev);
 310
 311         gpiochip_remove(&tc3589x_gpio->chip);
 312
 313         return 0;
 314 }
 315
 316 static struct platform_driver tc3589x_gpio_driver = {
 317         .driver.name    = "tc3589x-gpio",
 318         .driver.owner   = THIS_MODULE,
 319         .probe          = tc3589x_gpio_probe,
 320         .remove         = tc3589x_gpio_remove,
 321 };
 322
 323 static int __init tc3589x_gpio_init(void)
 324 {
 325         return platform_driver_register(&tc3589x_gpio_driver);
 326 }
 327 subsys_initcall(tc3589x_gpio_init);
 328
 329 static void __exit tc3589x_gpio_exit(void)
 330 {
 331         platform_driver_unregister(&tc3589x_gpio_driver);
 332 }
 333 module_exit(tc3589x_gpio_exit);
 334
 335 MODULE_LICENSE("GPL v2");
 336 MODULE_DESCRIPTION("TC3589x GPIO driver");
 337 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");