linux/drivers/mfd/retu-mfd.c
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   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
  41struct retu_dev {
  42        struct regmap                   *regmap;
  43        struct device                   *dev;
  44        struct mutex                    mutex;
  45        struct regmap_irq_chip_data     *irq_data;
  46};
  47
  48static const 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
  57static 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
  68static struct regmap_irq retu_irqs[] = {
  69        [RETU_INT_PWR] = {
  70                .mask = 1 << RETU_INT_PWR,
  71        }
  72};
  73
  74static 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. */
  85static struct retu_dev *retu_pm_power_off;
  86
  87static const 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
  96static 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
 104static struct regmap_irq tahvo_irqs[] = {
 105        [TAHVO_INT_VBUS] = {
 106                .mask = 1 << TAHVO_INT_VBUS,
 107        }
 108};
 109
 110static 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
 120static 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
 143int 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}
 154EXPORT_SYMBOL_GPL(retu_read);
 155
 156int 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}
 166EXPORT_SYMBOL_GPL(retu_write);
 167
 168static 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
 189static 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
 206static 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
 219static 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
 225static const struct regmap_config retu_config = {
 226        .reg_bits = 8,
 227        .val_bits = 16,
 228};
 229
 230static 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
 290static 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
 304static const struct i2c_device_id retu_id[] = {
 305        { "retu", 0 },
 306        { "tahvo", 0 },
 307        { }
 308};
 309MODULE_DEVICE_TABLE(i2c, retu_id);
 310
 311static const struct of_device_id retu_of_match[] = {
 312        { .compatible = "nokia,retu" },
 313        { .compatible = "nokia,tahvo" },
 314        { }
 315};
 316MODULE_DEVICE_TABLE(of, retu_of_match);
 317
 318static struct i2c_driver retu_driver = {
 319        .driver         = {
 320                .name = "retu-mfd",
 321                .of_match_table = retu_of_match,
 322        },
 323        .probe          = retu_probe,
 324        .remove         = retu_remove,
 325        .id_table       = retu_id,
 326};
 327module_i2c_driver(retu_driver);
 328
 329MODULE_DESCRIPTION("Retu MFD driver");
 330MODULE_AUTHOR("Juha Yrjölä");
 331MODULE_AUTHOR("David Weinehall");
 332MODULE_AUTHOR("Mikko Ylinen");
 333MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 334MODULE_LICENSE("GPL");
 335