1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * I2C driver for Maxim MAX8925 4 * 5 * Copyright (C) 2009 Marvell International Ltd. 6 * Haojian Zhuang <haojian.zhuang@marvell.com> 7 */ 8 #include <linux/kernel.h> 9 #include <linux/init.h> 10 #include <linux/platform_device.h> 11 #include <linux/i2c.h> 12 #include <linux/mfd/max8925.h> 13 #include <linux/slab.h> 14 15 #define RTC_I2C_ADDR 0x68 16 #define ADC_I2C_ADDR 0x47 17 18 static inline int max8925_read_device(struct i2c_client *i2c, 19 int reg, int bytes, void *dest) 20 { 21 int ret; 22 23 if (bytes > 1) 24 ret = i2c_smbus_read_i2c_block_data(i2c, reg, bytes, dest); 25 else { 26 ret = i2c_smbus_read_byte_data(i2c, reg); 27 if (ret < 0) 28 return ret; 29 *(unsigned char *)dest = (unsigned char)ret; 30 } 31 return ret; 32 } 33 34 static inline int max8925_write_device(struct i2c_client *i2c, 35 int reg, int bytes, void *src) 36 { 37 unsigned char buf[9]; 38 int ret; 39 40 buf[0] = (unsigned char)reg; 41 memcpy(&buf[1], src, bytes); 42 43 ret = i2c_master_send(i2c, buf, bytes + 1); 44 if (ret < 0) 45 return ret; 46 return 0; 47 } 48 49 int max8925_reg_read(struct i2c_client *i2c, int reg) 50 { 51 struct max8925_chip *chip = i2c_get_clientdata(i2c); 52 unsigned char data = 0; 53 int ret; 54 55 mutex_lock(&chip->io_lock); 56 ret = max8925_read_device(i2c, reg, 1, &data); 57 mutex_unlock(&chip->io_lock); 58 59 if (ret < 0) 60 return ret; 61 else 62 return (int)data; 63 } 64 EXPORT_SYMBOL(max8925_reg_read); 65 66 int max8925_reg_write(struct i2c_client *i2c, int reg, 67 unsigned char data) 68 { 69 struct max8925_chip *chip = i2c_get_clientdata(i2c); 70 int ret; 71 72 mutex_lock(&chip->io_lock); 73 ret = max8925_write_device(i2c, reg, 1, &data); 74 mutex_unlock(&chip->io_lock); 75 76 return ret; 77 } 78 EXPORT_SYMBOL(max8925_reg_write); 79 80 int max8925_bulk_read(struct i2c_client *i2c, int reg, 81 int count, unsigned char *buf) 82 { 83 struct max8925_chip *chip = i2c_get_clientdata(i2c); 84 int ret; 85 86 mutex_lock(&chip->io_lock); 87 ret = max8925_read_device(i2c, reg, count, buf); 88 mutex_unlock(&chip->io_lock); 89 90 return ret; 91 } 92 EXPORT_SYMBOL(max8925_bulk_read); 93 94 int max8925_bulk_write(struct i2c_client *i2c, int reg, 95 int count, unsigned char *buf) 96 { 97 struct max8925_chip *chip = i2c_get_clientdata(i2c); 98 int ret; 99 100 mutex_lock(&chip->io_lock); 101 ret = max8925_write_device(i2c, reg, count, buf); 102 mutex_unlock(&chip->io_lock); 103 104 return ret; 105 } 106 EXPORT_SYMBOL(max8925_bulk_write); 107 108 int max8925_set_bits(struct i2c_client *i2c, int reg, 109 unsigned char mask, unsigned char data) 110 { 111 struct max8925_chip *chip = i2c_get_clientdata(i2c); 112 unsigned char value; 113 int ret; 114 115 mutex_lock(&chip->io_lock); 116 ret = max8925_read_device(i2c, reg, 1, &value); 117 if (ret < 0) 118 goto out; 119 value &= ~mask; 120 value |= data; 121 ret = max8925_write_device(i2c, reg, 1, &value); 122 out: 123 mutex_unlock(&chip->io_lock); 124 return ret; 125 } 126 EXPORT_SYMBOL(max8925_set_bits); 127 128 129 static const struct i2c_device_id max8925_id_table[] = { 130 { "max8925", 0 }, 131 { }, 132 }; 133 134 static int max8925_dt_init(struct device_node *np, struct device *dev, 135 struct max8925_platform_data *pdata) 136 { 137 int ret; 138 139 ret = of_property_read_u32(np, "maxim,tsc-irq", &pdata->tsc_irq); 140 if (ret) { 141 dev_err(dev, "Not found maxim,tsc-irq property\n"); 142 return -EINVAL; 143 } 144 return 0; 145 } 146 147 static int max8925_probe(struct i2c_client *client, 148 const struct i2c_device_id *id) 149 { 150 struct max8925_platform_data *pdata = dev_get_platdata(&client->dev); 151 struct max8925_chip *chip; 152 struct device_node *node = client->dev.of_node; 153 154 if (node && !pdata) { 155 /* parse DT to get platform data */ 156 pdata = devm_kzalloc(&client->dev, 157 sizeof(struct max8925_platform_data), 158 GFP_KERNEL); 159 if (!pdata) 160 return -ENOMEM; 161 162 if (max8925_dt_init(node, &client->dev, pdata)) 163 return -EINVAL; 164 } else if (!pdata) { 165 pr_info("%s: platform data is missing\n", __func__); 166 return -EINVAL; 167 } 168 169 chip = devm_kzalloc(&client->dev, 170 sizeof(struct max8925_chip), GFP_KERNEL); 171 if (chip == NULL) 172 return -ENOMEM; 173 chip->i2c = client; 174 chip->dev = &client->dev; 175 i2c_set_clientdata(client, chip); 176 dev_set_drvdata(chip->dev, chip); 177 mutex_init(&chip->io_lock); 178 179 chip->rtc = i2c_new_dummy_device(chip->i2c->adapter, RTC_I2C_ADDR); 180 if (IS_ERR(chip->rtc)) { 181 dev_err(chip->dev, "Failed to allocate I2C device for RTC\n"); 182 return PTR_ERR(chip->rtc); 183 } 184 i2c_set_clientdata(chip->rtc, chip); 185 186 chip->adc = i2c_new_dummy_device(chip->i2c->adapter, ADC_I2C_ADDR); 187 if (IS_ERR(chip->adc)) { 188 dev_err(chip->dev, "Failed to allocate I2C device for ADC\n"); 189 i2c_unregister_device(chip->rtc); 190 return PTR_ERR(chip->adc); 191 } 192 i2c_set_clientdata(chip->adc, chip); 193 194 device_init_wakeup(&client->dev, 1); 195 196 max8925_device_init(chip, pdata); 197 198 return 0; 199 } 200 201 static void max8925_remove(struct i2c_client *client) 202 { 203 struct max8925_chip *chip = i2c_get_clientdata(client); 204 205 max8925_device_exit(chip); 206 i2c_unregister_device(chip->adc); 207 i2c_unregister_device(chip->rtc); 208 } 209 210 #ifdef CONFIG_PM_SLEEP 211 static int max8925_suspend(struct device *dev) 212 { 213 struct i2c_client *client = to_i2c_client(dev); 214 struct max8925_chip *chip = i2c_get_clientdata(client); 215 216 if (device_may_wakeup(dev) && chip->wakeup_flag) 217 enable_irq_wake(chip->core_irq); 218 return 0; 219 } 220 221 static int max8925_resume(struct device *dev) 222 { 223 struct i2c_client *client = to_i2c_client(dev); 224 struct max8925_chip *chip = i2c_get_clientdata(client); 225 226 if (device_may_wakeup(dev) && chip->wakeup_flag) 227 disable_irq_wake(chip->core_irq); 228 return 0; 229 } 230 #endif 231 232 static SIMPLE_DEV_PM_OPS(max8925_pm_ops, max8925_suspend, max8925_resume); 233 234 static const struct of_device_id max8925_dt_ids[] = { 235 { .compatible = "maxim,max8925", }, 236 {}, 237 }; 238 239 static struct i2c_driver max8925_driver = { 240 .driver = { 241 .name = "max8925", 242 .pm = &max8925_pm_ops, 243 .of_match_table = max8925_dt_ids, 244 }, 245 .probe = max8925_probe, 246 .remove = max8925_remove, 247 .id_table = max8925_id_table, 248 }; 249 250 static int __init max8925_i2c_init(void) 251 { 252 int ret; 253 254 ret = i2c_add_driver(&max8925_driver); 255 if (ret != 0) 256 pr_err("Failed to register MAX8925 I2C driver: %d\n", ret); 257 258 return ret; 259 } 260 subsys_initcall(max8925_i2c_init); 261