drivers/mfd/retu-mfd.c

   1 /*
   2  * Retu 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 */
  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 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 int retu_read(struct retu_dev *rdev, u8 reg)
  88 {
  89         int ret;
  90         int value;
  91
  92         mutex_lock(&rdev->mutex);
  93         ret = regmap_read(rdev->regmap, reg, &value);
  94         mutex_unlock(&rdev->mutex);
  95
  96         return ret ? ret : value;
  97 }
  98 EXPORT_SYMBOL_GPL(retu_read);
  99
 100 int retu_write(struct retu_dev *rdev, u8 reg, u16 data)
 101 {
 102         int ret;
 103
 104         mutex_lock(&rdev->mutex);
 105         ret = regmap_write(rdev->regmap, reg, data);
 106         mutex_unlock(&rdev->mutex);
 107
 108         return ret;
 109 }
 110 EXPORT_SYMBOL_GPL(retu_write);
 111
 112 static void retu_power_off(void)
 113 {
 114         struct retu_dev *rdev = retu_pm_power_off;
 115         int reg;
 116
 117         mutex_lock(&retu_pm_power_off->mutex);
 118
 119         /* Ignore power button state */
 120         regmap_read(rdev->regmap, RETU_REG_CC1, &reg);
 121         regmap_write(rdev->regmap, RETU_REG_CC1, reg | 2);
 122
 123         /* Expire watchdog immediately */
 124         regmap_write(rdev->regmap, RETU_REG_WATCHDOG, 0);
 125
 126         /* Wait for poweroff */
 127         for (;;)
 128                 cpu_relax();
 129
 130         mutex_unlock(&retu_pm_power_off->mutex);
 131 }
 132
 133 static int retu_regmap_read(void *context, const void *reg, size_t reg_size,
 134                             void *val, size_t val_size)
 135 {
 136         int ret;
 137         struct device *dev = context;
 138         struct i2c_client *i2c = to_i2c_client(dev);
 139
 140         BUG_ON(reg_size != 1 || val_size != 2);
 141
 142         ret = i2c_smbus_read_word_data(i2c, *(u8 const *)reg);
 143         if (ret < 0)
 144                 return ret;
 145
 146         *(u16 *)val = ret;
 147         return 0;
 148 }
 149
 150 static int retu_regmap_write(void *context, const void *data, size_t count)
 151 {
 152         u8 reg;
 153         u16 val;
 154         struct device *dev = context;
 155         struct i2c_client *i2c = to_i2c_client(dev);
 156
 157         BUG_ON(count != sizeof(reg) + sizeof(val));
 158         memcpy(&reg, data, sizeof(reg));
 159         memcpy(&val, data + sizeof(reg), sizeof(val));
 160         return i2c_smbus_write_word_data(i2c, reg, val);
 161 }
 162
 163 static struct regmap_bus retu_bus = {
 164         .read = retu_regmap_read,
 165         .write = retu_regmap_write,
 166         .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
 167 };
 168
 169 static struct regmap_config retu_config = {
 170         .reg_bits = 8,
 171         .val_bits = 16,
 172 };
 173
 174 static int __devinit retu_probe(struct i2c_client *i2c,
 175                                 const struct i2c_device_id *id)
 176 {
 177         struct retu_dev *rdev;
 178         int ret;
 179
 180         rdev = devm_kzalloc(&i2c->dev, sizeof(*rdev), GFP_KERNEL);
 181         if (rdev == NULL)
 182                 return -ENOMEM;
 183
 184         i2c_set_clientdata(i2c, rdev);
 185         rdev->dev = &i2c->dev;
 186         mutex_init(&rdev->mutex);
 187         rdev->regmap = devm_regmap_init(&i2c->dev, &retu_bus, &i2c->dev,
 188                                         &retu_config);
 189         if (IS_ERR(rdev->regmap))
 190                 return PTR_ERR(rdev->regmap);
 191
 192         ret = retu_read(rdev, RETU_REG_ASICR);
 193         if (ret < 0) {
 194                 dev_err(rdev->dev, "could not read Retu revision: %d\n", ret);
 195                 return ret;
 196         }
 197
 198         dev_info(rdev->dev, "Retu%s v%d.%d found\n",
 199                  (ret & RETU_REG_ASICR_VILMA) ? " & Vilma" : "",
 200                  (ret >> 4) & 0x7, ret & 0xf);
 201
 202         /* Mask all RETU interrupts. */
 203         ret = retu_write(rdev, RETU_REG_IMR, 0xffff);
 204         if (ret < 0)
 205                 return ret;
 206
 207         ret = regmap_add_irq_chip(rdev->regmap, i2c->irq, IRQF_ONESHOT, -1,
 208                                   &retu_irq_chip, &rdev->irq_data);
 209         if (ret < 0)
 210                 return ret;
 211
 212         ret = mfd_add_devices(rdev->dev, -1, retu_devs, ARRAY_SIZE(retu_devs),
 213                               NULL, regmap_irq_chip_get_base(rdev->irq_data),
 214                               NULL);
 215         if (ret < 0) {
 216                 regmap_del_irq_chip(i2c->irq, rdev->irq_data);
 217                 return ret;
 218         }
 219
 220         if (!pm_power_off) {
 221                 retu_pm_power_off = rdev;
 222                 pm_power_off      = retu_power_off;
 223         }
 224
 225         return 0;
 226 }
 227
 228 static int __devexit retu_remove(struct i2c_client *i2c)
 229 {
 230         struct retu_dev *rdev = i2c_get_clientdata(i2c);
 231
 232         if (retu_pm_power_off == rdev) {
 233                 pm_power_off      = NULL;
 234                 retu_pm_power_off = NULL;
 235         }
 236         mfd_remove_devices(rdev->dev);
 237         regmap_del_irq_chip(i2c->irq, rdev->irq_data);
 238
 239         return 0;
 240 }
 241
 242 static const struct i2c_device_id retu_id[] = {
 243         { "retu-mfd", 0 },
 244         { }
 245 };
 246 MODULE_DEVICE_TABLE(i2c, retu_id);
 247
 248 static struct i2c_driver retu_driver = {
 249         .driver         = {
 250                 .name = "retu-mfd",
 251                 .owner = THIS_MODULE,
 252         },
 253         .probe          = retu_probe,
 254         .remove         = retu_remove,
 255         .id_table       = retu_id,
 256 };
 257 module_i2c_driver(retu_driver);
 258
 259 MODULE_DESCRIPTION("Retu MFD driver");
 260 MODULE_AUTHOR("Juha Yrjölä");
 261 MODULE_AUTHOR("David Weinehall");
 262 MODULE_AUTHOR("Mikko Ylinen");
 263 MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
 264 MODULE_LICENSE("GPL");