drivers/mfd/retu-mfd.c

   1 /*
   2  * Retu/Tahvo MFD driver
   3  *
   4  * Copyright (C) 2004, 2005 Nokia Corporation
   5  *
   6  * Based on code written by Juha Yrjölä, David Weinehall and Mikko Ylinen.
   7  * Rewritten by Aaro Koskinen.
   8  *
   9  * This file is subject to the terms and conditions of the GNU General
  10  * Public License. See the file "COPYING" in the main directory of this
  11  * archive for more details.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  */
  18
  19 #include <linux/err.h>
  20 #include <linux/i2c.h>
  21 #include <linux/irq.h>
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/mutex.h>
  25 #include <linux/module.h>
  26 #include <linux/regmap.h>
  27 #include <linux/mfd/core.h>
  28 #include <linux/mfd/retu.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/moduleparam.h>
  31
  32 /* Registers */
  33 #define RETU_REG_ASICR          0x00            /* ASIC ID and revision */
  34 #define RETU_REG_ASICR_VILMA    (1 << 7)        /* Bit indicating Vilma */
  35 #define RETU_REG_IDR            0x01            /* Interrupt ID */
  36 #define RETU_REG_IMR            0x02            /* Interrupt mask (Retu) */
  37 #define TAHVO_REG_IMR           0x03            /* Interrupt mask (Tahvo) */
  38
  39 /* Interrupt sources */
  40 #define RETU_INT_PWR            0               /* Power button */
  41
  42 struct retu_dev {
  43         struct regmap                   *regmap;
  44         struct device                   *dev;
  45         struct mutex                    mutex;
  46         struct regmap_irq_chip_data     *irq_data;
  47 };
  48
  49 static struct resource retu_pwrbutton_res[] = {
  50         {
  51                 .name   = "retu-pwrbutton",
  52                 .start  = RETU_INT_PWR,
  53                 .end    = RETU_INT_PWR,
  54                 .flags  = IORESOURCE_IRQ,
  55         },
  56 };
  57
  58 static struct mfd_cell retu_devs[] = {
  59         {
  60                 .name           = "retu-wdt"
  61         },
  62         {
  63                 .name           = "retu-pwrbutton",
  64                 .resources      = retu_pwrbutton_res,
  65                 .num_resources  = ARRAY_SIZE(retu_pwrbutton_res),
  66         }
  67 };
  68
  69 static struct regmap_irq retu_irqs[] = {
  70         [RETU_INT_PWR] = {
  71                 .mask = 1 << RETU_INT_PWR,
  72         }
  73 };
  74
  75 static struct regmap_irq_chip retu_irq_chip = {
  76         .name           = "RETU",
  77         .irqs           = retu_irqs,
  78         .num_irqs       = ARRAY_SIZE(retu_irqs),
  79         .num_regs       = 1,
  80         .status_base    = RETU_REG_IDR,
  81         .mask_base      = RETU_REG_IMR,
  82         .ack_base       = RETU_REG_IDR,
  83 };
  84
  85 /* Retu device registered for the power off. */
  86 static struct retu_dev *retu_pm_power_off;
  87
  88 static struct resource tahvo_usb_res[] = {
  89         {
  90                 .name   = "tahvo-usb",
  91                 .start  = TAHVO_INT_VBUS,
  92                 .end    = TAHVO_INT_VBUS,
  93                 .flags  = IORESOURCE_IRQ,
  94         },
  95 };
  96
  97 static struct mfd_cell tahvo_devs[] = {
  98         {
  99                 .name           = "tahvo-usb",
 100                 .resources      = tahvo_usb_res,
 101                 .num_resources  = ARRAY_SIZE(tahvo_usb_res),
 102         },
 103 };
 104
 105 static struct regmap_irq tahvo_irqs[] = {
 106         [TAHVO_INT_VBUS] = {
 107                 .mask = 1 << TAHVO_INT_VBUS,
 108         }
 109 };
 110
 111 static struct regmap_irq_chip tahvo_irq_chip = {
 112         .name           = "TAHVO",
 113         .irqs           = tahvo_irqs,
 114         .num_irqs       = ARRAY_SIZE(tahvo_irqs),
 115         .num_regs       = 1,
 116         .status_base    = RETU_REG_IDR,
 117         .mask_base      = TAHVO_REG_IMR,
 118         .ack_base       = RETU_REG_IDR,
 119 };
 120
 121 static const struct retu_data {
 122         char                    *chip_name;
 123         char                    *companion_name;
 124         struct regmap_irq_chip  *irq_chip;
 125         struct mfd_cell         *children;
 126         int                     nchildren;
 127 } retu_data[] = {
 128         [0] = {
 129                 .chip_name      = "Retu",
 130                 .companion_name = "Vilma",
 131                 .irq_chip       = &retu_irq_chip,
 132                 .children       = retu_devs,
 133                 .nchildren      = ARRAY_SIZE(retu_devs),
 134         },
 135         [1] = {
 136                 .chip_name      = "Tahvo",
 137                 .companion_name = "Betty",
 138                 .irq_chip       = &tahvo_irq_chip,
 139                 .children       = tahvo_devs,
 140                 .nchildren      = ARRAY_SIZE(tahvo_devs),
 141         }
 142 };
 143
 144 int retu_read(struct retu_dev *rdev, u8 reg)
 145 {
 146         int ret;
 147         int value;
 148
 149         mutex_lock(&rdev->mutex);
 150         ret = regmap_read(rdev->regmap, reg, &value);
 151         mutex_unlock(&rdev->mutex);
 152
 153         return ret ? ret : value;
 154 }
 155 EXPORT_SYMBOL_GPL(retu_read);
 156
 157 int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
 158 {
 159         int ret;
 160
 161         mutex_lock(&rdev->mutex);
 162         ret = regmap_write(rdev->regmap, reg, data);
 163         mutex_unlock(&rdev->mutex);
 164
 165         return ret;
 166 }
 167 EXPORT_SYMBOL_GPL(retu_write);
 168
 169 static void retu_power_off(void)
 170 {
 171         struct retu_dev *rdev = retu_pm_power_off;
 172         int reg;
 173
 174         mutex_lock(&retu_pm_power_off->mutex);
 175
 176         /* Ignore power button state */
 177         regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
 178         regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);
 179
 180         /* Expire watchdog immediately */
 181         regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);
 182
 183         /* Wait for poweroff */
 184         for (;;)
 185                 cpu_relax();
 186
 187         mutex_unlock(&retu_pm_power_off->mutex);
 188 }
 189
 190 static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
 191                             void *val, size_t val_size)
 192 {
 193         int ret;
 194         struct device *dev = context;
 195         struct i2c_client *i2c = to_i2c_client(dev);
 196
 197         BUG_ON(reg_size != 1 || val_size != 2);
 198
 199         ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
 200         if (ret < 0)
 201                 return ret;
 202
 203         *(u16 *)val = ret;
 204         return 0;
 205 }
 206
 207 static int retu_regmap_write(void *context, const void *data, size_t count)
 208 {
 209         u8 reg;
 210         u16 val;
 211         struct device *dev = context;
 212         struct i2c_client *i2c = to_i2c_client(dev);
 213
 214         BUG_ON(count != sizeof(reg) + sizeof(val));
 215         memcpy(&reg, data, sizeof(reg));
 216         memcpy(&val, data + sizeof(reg), sizeof(val));
 217         return i2c_smbus_write_word_data(i2c, reg, val);
 218 }
 219
 220 static struct regmap_bus retu_bus = {
 221         .read = retu_regmap_read,
 222         .write = retu_regmap_write,
 223         .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
 224 };
 225
 226 static struct regmap_config retu_config = {
 227         .reg_bits = 8,
 228         .val_bits = 16,
 229 };
 230
 231 static int retu_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
 232 {
 233         struct retu_data const *rdat;
 234         struct retu_dev *rdev;
 235         int ret;
 236
 237         if (i2c->addr > ARRAY_SIZE(retu_data))
 238                 return -ENODEV;
 239         rdat = &retu_data[i2c->addr - 1];
 240
 241         rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
 242         if (rdev == NULL)
 243                 return -ENOMEM;
 244
 245         i2c_set_clientdata(i2c, rdev);
 246         rdev->dev = &i2c->dev;
 247         mutex_init(&rdev->mutex);
 248         rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
 249                                         &retu_config);
 250         if (IS_ERR(rdev->regmap))
 251                 return PTR_ERR(rdev->regmap);
 252
 253         ret = retu_read(rdev, RETU_REG_ASICR);
 254         if (ret < 0) {
 255                 dev_err(rdev->dev, "could not read %s revision: %d\n",
 256                         rdat->chip_name, ret);
 257                 return ret;
 258         }
 259
 260         dev_info(rdev->dev, "%s%s%s v%d.%d found\n", rdat->chip_name,
 261                  (ret & RETU_REG_ASICR_VILMA) ? " & " : "",
 262                  (ret & RETU_REG_ASICR_VILMA) ? rdat->companion_name : "",
 263                  (ret >> 4) & 0x7, ret & 0xf);
 264
 265         /* Mask all interrupts. */
 266         ret = retu_write(rdev, rdat->irq_chip->mask_base, 0xffff);
 267         if (ret < 0)
 268                 return ret;
 269
 270         ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
 271                                   rdat->irq_chip, &rdev->irq_data);
 272         if (ret < 0)
 273                 return ret;
 274
 275         ret = mfd_add_devices(rdev->dev, -1, rdat->children, rdat->nchildren,
 276                               NULL, regmap_irq_chip_get_base(rdev->irq_data),
 277                               NULL);
 278         if (ret < 0) {
 279                 regmap_del_irq_chip(i2c->irq, rdev->irq_data);
 280                 return ret;
 281         }
 282
 283         if (i2c->addr == 1 && !pm_power_off) {
 284                 retu_pm_power_off = rdev;
 285                 pm_power_off      = retu_power_off;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static int retu_remove(struct i2c_client *i2c)
 292 {
 293         struct retu_dev *rdev = i2c_get_clientdata(i2c);
 294
 295         if (retu_pm_power_off == rdev) {
 296                 pm_power_off      = NULL;
 297                 retu_pm_power_off = NULL;
 298         }
 299         mfd_remove_devices(rdev->dev);
 300         regmap_del_irq_chip(i2c->irq, rdev->irq_data);
 301
 302         return 0;
 303 }
 304
 305 static const struct i2c_device_id retu_id[] = {
 306         { "retu-mfd", 0 },
 307         { "tahvo-mfd", 0 },
 308         { }
 309 };
 310 MODULE_DEVICE_TABLE(i2c, retu_id);
 311
 312 static struct i2c_driver retu_driver = {
 313         .driver         = {
 314                 .name = "retu-mfd",
 315                 .owner = THIS_MODULE,
 316         },
 317         .probe          = retu_probe,
 318         .remove         = retu_remove,
 319         .id_table       = retu_id,
 320 };
 321 module_i2c_driver(retu_driver);
 322
 323 MODULE_DESCRIPTION("Retu MFD driver");
 324 MODULE_AUTHOR("Juha Yrjölä");
 325 MODULE_AUTHOR("David Weinehall");
 326 MODULE_AUTHOR("Mikko Ylinen");
 327 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 328 MODULE_LICENSE("GPL");