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