drivers/mfd/tc35892.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/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <linux/slab.h>
  13 #include <linux/i2c.h>
  14 #include <linux/mfd/core.h>
  15 #include <linux/mfd/tc35892.h>
  16
  17 /**
  18  * tc35892_reg_read() - read a single TC35892 register
  19  * @tc35892:    Device to read from
  20  * @reg:        Register to read
  21  */
  22 int tc35892_reg_read(struct tc35892 *tc35892, u8 reg)
  23 {
  24         int ret;
  25
  26         ret = i2c_smbus_read_byte_data(tc35892->i2c, reg);
  27         if (ret < 0)
  28                 dev_err(tc35892->dev, "failed to read reg %#x: %d\n",
  29                         reg, ret);
  30
  31         return ret;
  32 }
  33 EXPORT_SYMBOL_GPL(tc35892_reg_read);
  34
  35 /**
  36  * tc35892_reg_read() - write a single TC35892 register
  37  * @tc35892:    Device to write to
  38  * @reg:        Register to read
  39  * @data:       Value to write
  40  */
  41 int tc35892_reg_write(struct tc35892 *tc35892, u8 reg, u8 data)
  42 {
  43         int ret;
  44
  45         ret = i2c_smbus_write_byte_data(tc35892->i2c, reg, data);
  46         if (ret < 0)
  47                 dev_err(tc35892->dev, "failed to write reg %#x: %d\n",
  48                         reg, ret);
  49
  50         return ret;
  51 }
  52 EXPORT_SYMBOL_GPL(tc35892_reg_write);
  53
  54 /**
  55  * tc35892_block_read() - read multiple TC35892 registers
  56  * @tc35892:    Device to read from
  57  * @reg:        First register
  58  * @length:     Number of registers
  59  * @values:     Buffer to write to
  60  */
  61 int tc35892_block_read(struct tc35892 *tc35892, u8 reg, u8 length, u8 *values)
  62 {
  63         int ret;
  64
  65         ret = i2c_smbus_read_i2c_block_data(tc35892->i2c, reg, length, values);
  66         if (ret < 0)
  67                 dev_err(tc35892->dev, "failed to read regs %#x: %d\n",
  68                         reg, ret);
  69
  70         return ret;
  71 }
  72 EXPORT_SYMBOL_GPL(tc35892_block_read);
  73
  74 /**
  75  * tc35892_block_write() - write multiple TC35892 registers
  76  * @tc35892:    Device to write to
  77  * @reg:        First register
  78  * @length:     Number of registers
  79  * @values:     Values to write
  80  */
  81 int tc35892_block_write(struct tc35892 *tc35892, u8 reg, u8 length,
  82                         const u8 *values)
  83 {
  84         int ret;
  85
  86         ret = i2c_smbus_write_i2c_block_data(tc35892->i2c, reg, length,
  87                                              values);
  88         if (ret < 0)
  89                 dev_err(tc35892->dev, "failed to write regs %#x: %d\n",
  90                         reg, ret);
  91
  92         return ret;
  93 }
  94 EXPORT_SYMBOL_GPL(tc35892_block_write);
  95
  96 /**
  97  * tc35892_set_bits() - set the value of a bitfield in a TC35892 register
  98  * @tc35892:    Device to write to
  99  * @reg:        Register to write
 100  * @mask:       Mask of bits to set
 101  * @values:     Value to set
 102  */
 103 int tc35892_set_bits(struct tc35892 *tc35892, u8 reg, u8 mask, u8 val)
 104 {
 105         int ret;
 106
 107         mutex_lock(&tc35892->lock);
 108
 109         ret = tc35892_reg_read(tc35892, reg);
 110         if (ret < 0)
 111                 goto out;
 112
 113         ret &= ~mask;
 114         ret |= val;
 115
 116         ret = tc35892_reg_write(tc35892, reg, ret);
 117
 118 out:
 119         mutex_unlock(&tc35892->lock);
 120         return ret;
 121 }
 122 EXPORT_SYMBOL_GPL(tc35892_set_bits);
 123
 124 static struct resource gpio_resources[] = {
 125         {
 126                 .start  = TC35892_INT_GPIIRQ,
 127                 .end    = TC35892_INT_GPIIRQ,
 128                 .flags  = IORESOURCE_IRQ,
 129         },
 130 };
 131
 132 static struct mfd_cell tc35892_devs[] = {
 133         {
 134                 .name           = "tc35892-gpio",
 135                 .num_resources  = ARRAY_SIZE(gpio_resources),
 136                 .resources      = &gpio_resources[0],
 137         },
 138 };
 139
 140 static irqreturn_t tc35892_irq(int irq, void *data)
 141 {
 142         struct tc35892 *tc35892 = data;
 143         int status;
 144
 145         status = tc35892_reg_read(tc35892, TC35892_IRQST);
 146         if (status < 0)
 147                 return IRQ_NONE;
 148
 149         while (status) {
 150                 int bit = __ffs(status);
 151
 152                 handle_nested_irq(tc35892->irq_base + bit);
 153                 status &= ~(1 << bit);
 154         }
 155
 156         /*
 157          * A dummy read or write (to any register) appears to be necessary to
 158          * have the last interrupt clear (for example, GPIO IC write) take
 159          * effect.
 160          */
 161         tc35892_reg_read(tc35892, TC35892_IRQST);
 162
 163         return IRQ_HANDLED;
 164 }
 165
 166 static void tc35892_irq_dummy(unsigned int irq)
 167 {
 168         /* No mask/unmask at this level */
 169 }
 170
 171 static struct irq_chip tc35892_irq_chip = {
 172         .name   = "tc35892",
 173         .mask   = tc35892_irq_dummy,
 174         .unmask = tc35892_irq_dummy,
 175 };
 176
 177 static int tc35892_irq_init(struct tc35892 *tc35892)
 178 {
 179         int base = tc35892->irq_base;
 180         int irq;
 181
 182         for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) {
 183                 set_irq_chip_data(irq, tc35892);
 184                 set_irq_chip_and_handler(irq, &tc35892_irq_chip,
 185                                          handle_edge_irq);
 186                 set_irq_nested_thread(irq, 1);
 187 #ifdef CONFIG_ARM
 188                 set_irq_flags(irq, IRQF_VALID);
 189 #else
 190                 set_irq_noprobe(irq);
 191 #endif
 192         }
 193
 194         return 0;
 195 }
 196
 197 static void tc35892_irq_remove(struct tc35892 *tc35892)
 198 {
 199         int base = tc35892->irq_base;
 200         int irq;
 201
 202         for (irq = base; irq < base + TC35892_NR_INTERNAL_IRQS; irq++) {
 203 #ifdef CONFIG_ARM
 204                 set_irq_flags(irq, 0);
 205 #endif
 206                 set_irq_chip_and_handler(irq, NULL, NULL);
 207                 set_irq_chip_data(irq, NULL);
 208         }
 209 }
 210
 211 static int tc35892_chip_init(struct tc35892 *tc35892)
 212 {
 213         int manf, ver, ret;
 214
 215         manf = tc35892_reg_read(tc35892, TC35892_MANFCODE);
 216         if (manf < 0)
 217                 return manf;
 218
 219         ver = tc35892_reg_read(tc35892, TC35892_VERSION);
 220         if (ver < 0)
 221                 return ver;
 222
 223         if (manf != TC35892_MANFCODE_MAGIC) {
 224                 dev_err(tc35892->dev, "unknown manufacturer: %#x\n", manf);
 225                 return -EINVAL;
 226         }
 227
 228         dev_info(tc35892->dev, "manufacturer: %#x, version: %#x\n", manf, ver);
 229
 230         /* Put everything except the IRQ module into reset */
 231         ret = tc35892_reg_write(tc35892, TC35892_RSTCTRL,
 232                                 TC35892_RSTCTRL_TIMRST
 233                                 | TC35892_RSTCTRL_ROTRST
 234                                 | TC35892_RSTCTRL_KBDRST
 235                                 | TC35892_RSTCTRL_GPIRST);
 236         if (ret < 0)
 237                 return ret;
 238
 239         /* Clear the reset interrupt. */
 240         return tc35892_reg_write(tc35892, TC35892_RSTINTCLR, 0x1);
 241 }
 242
 243 static int __devinit tc35892_probe(struct i2c_client *i2c,
 244                                    const struct i2c_device_id *id)
 245 {
 246         struct tc35892_platform_data *pdata = i2c->dev.platform_data;
 247         struct tc35892 *tc35892;
 248         int ret;
 249
 250         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA
 251                                      | I2C_FUNC_SMBUS_I2C_BLOCK))
 252                 return -EIO;
 253
 254         tc35892 = kzalloc(sizeof(struct tc35892), GFP_KERNEL);
 255         if (!tc35892)
 256                 return -ENOMEM;
 257
 258         mutex_init(&tc35892->lock);
 259
 260         tc35892->dev = &i2c->dev;
 261         tc35892->i2c = i2c;
 262         tc35892->pdata = pdata;
 263         tc35892->irq_base = pdata->irq_base;
 264         tc35892->num_gpio = id->driver_data;
 265
 266         i2c_set_clientdata(i2c, tc35892);
 267
 268         ret = tc35892_chip_init(tc35892);
 269         if (ret)
 270                 goto out_free;
 271
 272         ret = tc35892_irq_init(tc35892);
 273         if (ret)
 274                 goto out_free;
 275
 276         ret = request_threaded_irq(tc35892->i2c->irq, NULL, tc35892_irq,
 277                                    IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 278                                    "tc35892", tc35892);
 279         if (ret) {
 280                 dev_err(tc35892->dev, "failed to request IRQ: %d\n", ret);
 281                 goto out_removeirq;
 282         }
 283
 284         ret = mfd_add_devices(tc35892->dev, -1, tc35892_devs,
 285                               ARRAY_SIZE(tc35892_devs), NULL,
 286                               tc35892->irq_base);
 287         if (ret) {
 288                 dev_err(tc35892->dev, "failed to add children\n");
 289                 goto out_freeirq;
 290         }
 291
 292         return 0;
 293
 294 out_freeirq:
 295         free_irq(tc35892->i2c->irq, tc35892);
 296 out_removeirq:
 297         tc35892_irq_remove(tc35892);
 298 out_free:
 299         i2c_set_clientdata(i2c, NULL);
 300         kfree(tc35892);
 301         return ret;
 302 }
 303
 304 static int __devexit tc35892_remove(struct i2c_client *client)
 305 {
 306         struct tc35892 *tc35892 = i2c_get_clientdata(client);
 307
 308         mfd_remove_devices(tc35892->dev);
 309
 310         free_irq(tc35892->i2c->irq, tc35892);
 311         tc35892_irq_remove(tc35892);
 312
 313         i2c_set_clientdata(client, NULL);
 314         kfree(tc35892);
 315
 316         return 0;
 317 }
 318
 319 static const struct i2c_device_id tc35892_id[] = {
 320         { "tc35892", 24 },
 321         { }
 322 };
 323 MODULE_DEVICE_TABLE(i2c, tc35892_id);
 324
 325 static struct i2c_driver tc35892_driver = {
 326         .driver.name    = "tc35892",
 327         .driver.owner   = THIS_MODULE,
 328         .probe          = tc35892_probe,
 329         .remove         = __devexit_p(tc35892_remove),
 330         .id_table       = tc35892_id,
 331 };
 332
 333 static int __init tc35892_init(void)
 334 {
 335         return i2c_add_driver(&tc35892_driver);
 336 }
 337 subsys_initcall(tc35892_init);
 338
 339 static void __exit tc35892_exit(void)
 340 {
 341         i2c_del_driver(&tc35892_driver);
 342 }
 343 module_exit(tc35892_exit);
 344
 345 MODULE_LICENSE("GPL v2");
 346 MODULE_DESCRIPTION("TC35892 MFD core driver");
 347 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");