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, ®); 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(®, 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"); 265