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/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
  42struct retu_dev {
  43        struct regmap                   *regmap;
  44        struct device                   *dev;
  45        struct mutex                    mutex;
  46        struct regmap_irq_chip_data     *irq_data;
  47};
  48
  49static 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
  58static 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
  69static struct regmap_irq retu_irqs[] = {
  70        [RETU_INT_PWR] = {
  71                .mask = 1 << RETU_INT_PWR,
  72        }
  73};
  74
  75static 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. */
  86static struct retu_dev *retu_pm_power_off;
  87
  88static 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
  97static 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
 105static struct regmap_irq tahvo_irqs[] = {
 106        [TAHVO_INT_VBUS] = {
 107                .mask = 1 << TAHVO_INT_VBUS,
 108        }
 109};
 110
 111static 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
 121static 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
 144int 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}
 155EXPORT_SYMBOL_GPL(retu_read);
 156
 157int 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}
 167EXPORT_SYMBOL_GPL(retu_write);
 168
 169static 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
 190static 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
 207static 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
 220static 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
 226static struct regmap_config retu_config = {
 227        .reg_bits = 8,
 228        .val_bits = 16,
 229};
 230
 231static 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
 291static 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
 305static const struct i2c_device_id retu_id[] = {
 306        { "retu-mfd", 0 },
 307        { "tahvo-mfd", 0 },
 308        { }
 309};
 310MODULE_DEVICE_TABLE(i2c, retu_id);
 311
 312static 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};
 321module_i2c_driver(retu_driver);
 322
 323MODULE_DESCRIPTION("Retu MFD driver");
 324MODULE_AUTHOR("Juha Yrjölä");
 325MODULE_AUTHOR("David Weinehall");
 326MODULE_AUTHOR("Mikko Ylinen");
 327MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 328MODULE_LICENSE("GPL");
 329
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