1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Intel CHT Whiskey Cove PMIC I2C Master driver 4 * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com> 5 * 6 * Based on various non upstream patches to support the CHT Whiskey Cove PMIC: 7 * Copyright (C) 2011 - 2014 Intel Corporation. All rights reserved. 8 */ 9 10 #include <linux/acpi.h> 11 #include <linux/completion.h> 12 #include <linux/delay.h> 13 #include <linux/i2c.h> 14 #include <linux/interrupt.h> 15 #include <linux/irq.h> 16 #include <linux/irqdomain.h> 17 #include <linux/mfd/intel_soc_pmic.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/power/bq24190_charger.h> 21 #include <linux/slab.h> 22 23 #define CHT_WC_I2C_CTRL 0x5e24 24 #define CHT_WC_I2C_CTRL_WR BIT(0) 25 #define CHT_WC_I2C_CTRL_RD BIT(1) 26 #define CHT_WC_I2C_CLIENT_ADDR 0x5e25 27 #define CHT_WC_I2C_REG_OFFSET 0x5e26 28 #define CHT_WC_I2C_WRDATA 0x5e27 29 #define CHT_WC_I2C_RDDATA 0x5e28 30 31 #define CHT_WC_EXTCHGRIRQ 0x6e0a 32 #define CHT_WC_EXTCHGRIRQ_CLIENT_IRQ BIT(0) 33 #define CHT_WC_EXTCHGRIRQ_WRITE_IRQ BIT(1) 34 #define CHT_WC_EXTCHGRIRQ_READ_IRQ BIT(2) 35 #define CHT_WC_EXTCHGRIRQ_NACK_IRQ BIT(3) 36 #define CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK ((u8)GENMASK(3, 1)) 37 #define CHT_WC_EXTCHGRIRQ_MSK 0x6e17 38 39 struct cht_wc_i2c_adap { 40 struct i2c_adapter adapter; 41 wait_queue_head_t wait; 42 struct irq_chip irqchip; 43 struct mutex adap_lock; 44 struct mutex irqchip_lock; 45 struct regmap *regmap; 46 struct irq_domain *irq_domain; 47 struct i2c_client *client; 48 int client_irq; 49 u8 irq_mask; 50 u8 old_irq_mask; 51 int read_data; 52 bool io_error; 53 bool done; 54 }; 55 56 static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data) 57 { 58 struct cht_wc_i2c_adap *adap = data; 59 int ret, reg; 60 61 mutex_lock(&adap->adap_lock); 62 63 /* Read IRQs */ 64 ret = regmap_read(adap->regmap, CHT_WC_EXTCHGRIRQ, ®); 65 if (ret) { 66 dev_err(&adap->adapter.dev, "Error reading extchgrirq reg\n"); 67 mutex_unlock(&adap->adap_lock); 68 return IRQ_NONE; 69 } 70 71 reg &= ~adap->irq_mask; 72 73 /* Reads must be acked after reading the received data. */ 74 ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &adap->read_data); 75 if (ret) 76 adap->io_error = true; 77 78 /* 79 * Immediately ack IRQs, so that if new IRQs arrives while we're 80 * handling the previous ones our irq will re-trigger when we're done. 81 */ 82 ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, reg); 83 if (ret) 84 dev_err(&adap->adapter.dev, "Error writing extchgrirq reg\n"); 85 86 if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) { 87 adap->io_error |= !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ); 88 adap->done = true; 89 } 90 91 mutex_unlock(&adap->adap_lock); 92 93 if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) 94 wake_up(&adap->wait); 95 96 /* 97 * Do NOT use handle_nested_irq here, the client irq handler will 98 * likely want to do i2c transfers and the i2c controller uses this 99 * interrupt handler as well, so running the client irq handler from 100 * this thread will cause things to lock up. 101 */ 102 if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ) { 103 /* 104 * generic_handle_irq expects local IRQs to be disabled 105 * as normally it is called from interrupt context. 106 */ 107 local_irq_disable(); 108 generic_handle_irq(adap->client_irq); 109 local_irq_enable(); 110 } 111 112 return IRQ_HANDLED; 113 } 114 115 static u32 cht_wc_i2c_adap_master_func(struct i2c_adapter *adap) 116 { 117 /* This i2c adapter only supports SMBUS byte transfers */ 118 return I2C_FUNC_SMBUS_BYTE_DATA; 119 } 120 121 static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr, 122 unsigned short flags, char read_write, 123 u8 command, int size, 124 union i2c_smbus_data *data) 125 { 126 struct cht_wc_i2c_adap *adap = i2c_get_adapdata(_adap); 127 int ret; 128 129 mutex_lock(&adap->adap_lock); 130 adap->io_error = false; 131 adap->done = false; 132 mutex_unlock(&adap->adap_lock); 133 134 ret = regmap_write(adap->regmap, CHT_WC_I2C_CLIENT_ADDR, addr); 135 if (ret) 136 return ret; 137 138 if (read_write == I2C_SMBUS_WRITE) { 139 ret = regmap_write(adap->regmap, CHT_WC_I2C_WRDATA, data->byte); 140 if (ret) 141 return ret; 142 } 143 144 ret = regmap_write(adap->regmap, CHT_WC_I2C_REG_OFFSET, command); 145 if (ret) 146 return ret; 147 148 ret = regmap_write(adap->regmap, CHT_WC_I2C_CTRL, 149 (read_write == I2C_SMBUS_WRITE) ? 150 CHT_WC_I2C_CTRL_WR : CHT_WC_I2C_CTRL_RD); 151 if (ret) 152 return ret; 153 154 ret = wait_event_timeout(adap->wait, adap->done, msecs_to_jiffies(30)); 155 if (ret == 0) { 156 /* 157 * The CHT GPIO controller serializes all IRQs, sometimes 158 * causing significant delays, check status manually. 159 */ 160 cht_wc_i2c_adap_thread_handler(0, adap); 161 if (!adap->done) 162 return -ETIMEDOUT; 163 } 164 165 ret = 0; 166 mutex_lock(&adap->adap_lock); 167 if (adap->io_error) 168 ret = -EIO; 169 else if (read_write == I2C_SMBUS_READ) 170 data->byte = adap->read_data; 171 mutex_unlock(&adap->adap_lock); 172 173 return ret; 174 } 175 176 static const struct i2c_algorithm cht_wc_i2c_adap_algo = { 177 .functionality = cht_wc_i2c_adap_master_func, 178 .smbus_xfer = cht_wc_i2c_adap_smbus_xfer, 179 }; 180 181 /* 182 * We are an i2c-adapter which itself is part of an i2c-client. This means that 183 * transfers done through us take adapter->bus_lock twice, once for our parent 184 * i2c-adapter and once to take our own bus_lock. Lockdep does not like this 185 * nested locking, to make lockdep happy in the case of busses with muxes, the 186 * i2c-core's i2c_adapter_lock_bus function calls: 187 * rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); 188 * 189 * But i2c_adapter_depth only works when the direct parent of the adapter is 190 * another adapter, as it is only meant for muxes. In our case there is an 191 * i2c-client and MFD instantiated platform_device in the parent->child chain 192 * between the 2 devices. 193 * 194 * So we override the default i2c_lock_operations and pass a hardcoded 195 * depth of 1 to rt_mutex_lock_nested, to make lockdep happy. 196 * 197 * Note that if there were to be a mux attached to our adapter, this would 198 * break things again since the i2c-mux code expects the root-adapter to have 199 * a locking depth of 0. But we always have only 1 client directly attached 200 * in the form of the Charger IC paired with the CHT Whiskey Cove PMIC. 201 */ 202 static void cht_wc_i2c_adap_lock_bus(struct i2c_adapter *adapter, 203 unsigned int flags) 204 { 205 rt_mutex_lock_nested(&adapter->bus_lock, 1); 206 } 207 208 static int cht_wc_i2c_adap_trylock_bus(struct i2c_adapter *adapter, 209 unsigned int flags) 210 { 211 return rt_mutex_trylock(&adapter->bus_lock); 212 } 213 214 static void cht_wc_i2c_adap_unlock_bus(struct i2c_adapter *adapter, 215 unsigned int flags) 216 { 217 rt_mutex_unlock(&adapter->bus_lock); 218 } 219 220 static const struct i2c_lock_operations cht_wc_i2c_adap_lock_ops = { 221 .lock_bus = cht_wc_i2c_adap_lock_bus, 222 .trylock_bus = cht_wc_i2c_adap_trylock_bus, 223 .unlock_bus = cht_wc_i2c_adap_unlock_bus, 224 }; 225 226 /**** irqchip for the client connected to the extchgr i2c adapter ****/ 227 static void cht_wc_i2c_irq_lock(struct irq_data *data) 228 { 229 struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data); 230 231 mutex_lock(&adap->irqchip_lock); 232 } 233 234 static void cht_wc_i2c_irq_sync_unlock(struct irq_data *data) 235 { 236 struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data); 237 int ret; 238 239 if (adap->irq_mask != adap->old_irq_mask) { 240 ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK, 241 adap->irq_mask); 242 if (ret == 0) 243 adap->old_irq_mask = adap->irq_mask; 244 else 245 dev_err(&adap->adapter.dev, "Error writing EXTCHGRIRQ_MSK\n"); 246 } 247 248 mutex_unlock(&adap->irqchip_lock); 249 } 250 251 static void cht_wc_i2c_irq_enable(struct irq_data *data) 252 { 253 struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data); 254 255 adap->irq_mask &= ~CHT_WC_EXTCHGRIRQ_CLIENT_IRQ; 256 } 257 258 static void cht_wc_i2c_irq_disable(struct irq_data *data) 259 { 260 struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data); 261 262 adap->irq_mask |= CHT_WC_EXTCHGRIRQ_CLIENT_IRQ; 263 } 264 265 static const struct irq_chip cht_wc_i2c_irq_chip = { 266 .irq_bus_lock = cht_wc_i2c_irq_lock, 267 .irq_bus_sync_unlock = cht_wc_i2c_irq_sync_unlock, 268 .irq_disable = cht_wc_i2c_irq_disable, 269 .irq_enable = cht_wc_i2c_irq_enable, 270 .name = "cht_wc_ext_chrg_irq_chip", 271 }; 272 273 static const char * const bq24190_suppliers[] = { 274 "tcpm-source-psy-i2c-fusb302" }; 275 276 static const struct property_entry bq24190_props[] = { 277 PROPERTY_ENTRY_STRING_ARRAY("supplied-from", bq24190_suppliers), 278 PROPERTY_ENTRY_BOOL("omit-battery-class"), 279 PROPERTY_ENTRY_BOOL("disable-reset"), 280 { } 281 }; 282 283 static const struct software_node bq24190_node = { 284 .properties = bq24190_props, 285 }; 286 287 static struct regulator_consumer_supply fusb302_consumer = { 288 .supply = "vbus", 289 /* Must match fusb302 dev_name in intel_cht_int33fe.c */ 290 .dev_name = "i2c-fusb302", 291 }; 292 293 static const struct regulator_init_data bq24190_vbus_init_data = { 294 .constraints = { 295 /* The name is used in intel_cht_int33fe.c do not change. */ 296 .name = "cht_wc_usb_typec_vbus", 297 .valid_ops_mask = REGULATOR_CHANGE_STATUS, 298 }, 299 .consumer_supplies = &fusb302_consumer, 300 .num_consumer_supplies = 1, 301 }; 302 303 static struct bq24190_platform_data bq24190_pdata = { 304 .regulator_init_data = &bq24190_vbus_init_data, 305 }; 306 307 static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev) 308 { 309 struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent); 310 struct cht_wc_i2c_adap *adap; 311 struct i2c_board_info board_info = { 312 .type = "bq24190", 313 .addr = 0x6b, 314 .dev_name = "bq24190", 315 .swnode = &bq24190_node, 316 .platform_data = &bq24190_pdata, 317 }; 318 int ret, reg, irq; 319 320 irq = platform_get_irq(pdev, 0); 321 if (irq < 0) 322 return irq; 323 324 adap = devm_kzalloc(&pdev->dev, sizeof(*adap), GFP_KERNEL); 325 if (!adap) 326 return -ENOMEM; 327 328 init_waitqueue_head(&adap->wait); 329 mutex_init(&adap->adap_lock); 330 mutex_init(&adap->irqchip_lock); 331 adap->irqchip = cht_wc_i2c_irq_chip; 332 adap->regmap = pmic->regmap; 333 adap->adapter.owner = THIS_MODULE; 334 adap->adapter.class = I2C_CLASS_HWMON; 335 adap->adapter.algo = &cht_wc_i2c_adap_algo; 336 adap->adapter.lock_ops = &cht_wc_i2c_adap_lock_ops; 337 strlcpy(adap->adapter.name, "PMIC I2C Adapter", 338 sizeof(adap->adapter.name)); 339 adap->adapter.dev.parent = &pdev->dev; 340 341 /* Clear and activate i2c-adapter interrupts, disable client IRQ */ 342 adap->old_irq_mask = adap->irq_mask = ~CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK; 343 344 ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, ®); 345 if (ret) 346 return ret; 347 348 ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, ~adap->irq_mask); 349 if (ret) 350 return ret; 351 352 ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK, adap->irq_mask); 353 if (ret) 354 return ret; 355 356 /* Alloc and register client IRQ */ 357 adap->irq_domain = irq_domain_add_linear(NULL, 1, &irq_domain_simple_ops, NULL); 358 if (!adap->irq_domain) 359 return -ENOMEM; 360 361 adap->client_irq = irq_create_mapping(adap->irq_domain, 0); 362 if (!adap->client_irq) { 363 ret = -ENOMEM; 364 goto remove_irq_domain; 365 } 366 367 irq_set_chip_data(adap->client_irq, adap); 368 irq_set_chip_and_handler(adap->client_irq, &adap->irqchip, 369 handle_simple_irq); 370 371 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, 372 cht_wc_i2c_adap_thread_handler, 373 IRQF_ONESHOT, "PMIC I2C Adapter", adap); 374 if (ret) 375 goto remove_irq_domain; 376 377 i2c_set_adapdata(&adap->adapter, adap); 378 ret = i2c_add_adapter(&adap->adapter); 379 if (ret) 380 goto remove_irq_domain; 381 382 /* 383 * Normally the Whiskey Cove PMIC is paired with a TI bq24292i charger, 384 * connected to this i2c bus, and a max17047 fuel-gauge and a fusb302 385 * USB Type-C controller connected to another i2c bus. In this setup 386 * the max17047 and fusb302 devices are enumerated through an INT33FE 387 * ACPI device. If this device is present register an i2c-client for 388 * the TI bq24292i charger. 389 */ 390 if (acpi_dev_present("INT33FE", NULL, -1)) { 391 board_info.irq = adap->client_irq; 392 adap->client = i2c_new_client_device(&adap->adapter, &board_info); 393 if (IS_ERR(adap->client)) { 394 ret = PTR_ERR(adap->client); 395 goto del_adapter; 396 } 397 } 398 399 platform_set_drvdata(pdev, adap); 400 return 0; 401 402 del_adapter: 403 i2c_del_adapter(&adap->adapter); 404 remove_irq_domain: 405 irq_domain_remove(adap->irq_domain); 406 return ret; 407 } 408 409 static int cht_wc_i2c_adap_i2c_remove(struct platform_device *pdev) 410 { 411 struct cht_wc_i2c_adap *adap = platform_get_drvdata(pdev); 412 413 i2c_unregister_device(adap->client); 414 i2c_del_adapter(&adap->adapter); 415 irq_domain_remove(adap->irq_domain); 416 417 return 0; 418 } 419 420 static const struct platform_device_id cht_wc_i2c_adap_id_table[] = { 421 { .name = "cht_wcove_ext_chgr" }, 422 {}, 423 }; 424 MODULE_DEVICE_TABLE(platform, cht_wc_i2c_adap_id_table); 425 426 static struct platform_driver cht_wc_i2c_adap_driver = { 427 .probe = cht_wc_i2c_adap_i2c_probe, 428 .remove = cht_wc_i2c_adap_i2c_remove, 429 .driver = { 430 .name = "cht_wcove_ext_chgr", 431 }, 432 .id_table = cht_wc_i2c_adap_id_table, 433 }; 434 module_platform_driver(cht_wc_i2c_adap_driver); 435 436 MODULE_DESCRIPTION("Intel CHT Whiskey Cove PMIC I2C Master driver"); 437 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 438 MODULE_LICENSE("GPL"); 439