1 /* 2 * Synopsys DesignWare I2C adapter driver (master only). 3 * 4 * Based on the TI DAVINCI I2C adapter driver. 5 * 6 * Copyright (C) 2006 Texas Instruments. 7 * Copyright (C) 2007 MontaVista Software Inc. 8 * Copyright (C) 2009 Provigent Ltd. 9 * 10 * ---------------------------------------------------------------------------- 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * ---------------------------------------------------------------------------- 22 * 23 */ 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/delay.h> 27 #include <linux/dmi.h> 28 #include <linux/i2c.h> 29 #include <linux/clk.h> 30 #include <linux/clk-provider.h> 31 #include <linux/errno.h> 32 #include <linux/sched.h> 33 #include <linux/err.h> 34 #include <linux/interrupt.h> 35 #include <linux/of.h> 36 #include <linux/platform_device.h> 37 #include <linux/pm.h> 38 #include <linux/pm_runtime.h> 39 #include <linux/io.h> 40 #include <linux/slab.h> 41 #include <linux/acpi.h> 42 #include <linux/platform_data/i2c-designware.h> 43 #include "i2c-designware-core.h" 44 45 static struct i2c_algorithm i2c_dw_algo = { 46 .master_xfer = i2c_dw_xfer, 47 .functionality = i2c_dw_func, 48 }; 49 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 50 { 51 return clk_get_rate(dev->clk)/1000; 52 } 53 54 #ifdef CONFIG_ACPI 55 /* 56 * The HCNT/LCNT information coming from ACPI should be the most accurate 57 * for given platform. However, some systems get it wrong. On such systems 58 * we get better results by calculating those based on the input clock. 59 */ 60 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 61 { 62 .ident = "Dell Inspiron 7348", 63 .matches = { 64 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 65 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 66 }, 67 }, 68 { } 69 }; 70 71 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 72 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 73 { 74 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 75 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 76 union acpi_object *obj; 77 78 if (dmi_check_system(dw_i2c_no_acpi_params)) 79 return; 80 81 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 82 return; 83 84 obj = (union acpi_object *)buf.pointer; 85 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 86 const union acpi_object *objs = obj->package.elements; 87 88 *hcnt = (u16)objs[0].integer.value; 89 *lcnt = (u16)objs[1].integer.value; 90 if (sda_hold) 91 *sda_hold = (u32)objs[2].integer.value; 92 } 93 94 kfree(buf.pointer); 95 } 96 97 static int dw_i2c_acpi_configure(struct platform_device *pdev) 98 { 99 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 100 const struct acpi_device_id *id; 101 102 dev->adapter.nr = -1; 103 dev->tx_fifo_depth = 32; 104 dev->rx_fifo_depth = 32; 105 106 /* 107 * Try to get SDA hold time and *CNT values from an ACPI method if 108 * it exists for both supported speed modes. 109 */ 110 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 111 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 112 &dev->sda_hold_time); 113 114 /* 115 * Provide a way for Designware I2C host controllers that are not 116 * based on Intel LPSS to specify their input clock frequency via 117 * id->driver_data. 118 */ 119 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 120 if (id && id->driver_data) 121 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL, 122 CLK_IS_ROOT, id->driver_data); 123 124 return 0; 125 } 126 127 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev) 128 { 129 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 130 const struct acpi_device_id *id; 131 132 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 133 if (id && id->driver_data) 134 clk_unregister(dev->clk); 135 } 136 137 static const struct acpi_device_id dw_i2c_acpi_match[] = { 138 { "INT33C2", 0 }, 139 { "INT33C3", 0 }, 140 { "INT3432", 0 }, 141 { "INT3433", 0 }, 142 { "80860F41", 0 }, 143 { "808622C1", 0 }, 144 { "AMD0010", 133 * 1000 * 1000 }, 145 { } 146 }; 147 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 148 #else 149 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 150 { 151 return -ENODEV; 152 } 153 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { } 154 #endif 155 156 static int dw_i2c_probe(struct platform_device *pdev) 157 { 158 struct dw_i2c_dev *dev; 159 struct i2c_adapter *adap; 160 struct resource *mem; 161 struct dw_i2c_platform_data *pdata; 162 int irq, r; 163 u32 clk_freq, ht = 0; 164 165 irq = platform_get_irq(pdev, 0); 166 if (irq < 0) 167 return irq; 168 169 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 170 if (!dev) 171 return -ENOMEM; 172 173 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 174 dev->base = devm_ioremap_resource(&pdev->dev, mem); 175 if (IS_ERR(dev->base)) 176 return PTR_ERR(dev->base); 177 178 init_completion(&dev->cmd_complete); 179 mutex_init(&dev->lock); 180 dev->dev = &pdev->dev; 181 dev->irq = irq; 182 platform_set_drvdata(pdev, dev); 183 184 /* fast mode by default because of legacy reasons */ 185 clk_freq = 400000; 186 187 if (has_acpi_companion(&pdev->dev)) { 188 dw_i2c_acpi_configure(pdev); 189 } else if (pdev->dev.of_node) { 190 of_property_read_u32(pdev->dev.of_node, 191 "i2c-sda-hold-time-ns", &ht); 192 193 of_property_read_u32(pdev->dev.of_node, 194 "i2c-sda-falling-time-ns", 195 &dev->sda_falling_time); 196 of_property_read_u32(pdev->dev.of_node, 197 "i2c-scl-falling-time-ns", 198 &dev->scl_falling_time); 199 200 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 201 &clk_freq); 202 203 /* Only standard mode at 100kHz and fast mode at 400kHz 204 * are supported. 205 */ 206 if (clk_freq != 100000 && clk_freq != 400000) { 207 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 208 return -EINVAL; 209 } 210 } else { 211 pdata = dev_get_platdata(&pdev->dev); 212 if (pdata) 213 clk_freq = pdata->i2c_scl_freq; 214 } 215 216 r = i2c_dw_eval_lock_support(dev); 217 if (r) 218 return r; 219 220 dev->functionality = 221 I2C_FUNC_I2C | 222 I2C_FUNC_10BIT_ADDR | 223 I2C_FUNC_SMBUS_BYTE | 224 I2C_FUNC_SMBUS_BYTE_DATA | 225 I2C_FUNC_SMBUS_WORD_DATA | 226 I2C_FUNC_SMBUS_I2C_BLOCK; 227 if (clk_freq == 100000) 228 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 229 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 230 else 231 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 232 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 233 234 dev->clk = devm_clk_get(&pdev->dev, NULL); 235 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 236 if (IS_ERR(dev->clk)) 237 return PTR_ERR(dev->clk); 238 clk_prepare_enable(dev->clk); 239 240 if (!dev->sda_hold_time && ht) { 241 u32 ic_clk = dev->get_clk_rate_khz(dev); 242 243 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 244 1000000); 245 } 246 247 if (!dev->tx_fifo_depth) { 248 u32 param1 = i2c_dw_read_comp_param(dev); 249 250 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 251 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 252 dev->adapter.nr = pdev->id; 253 } 254 r = i2c_dw_init(dev); 255 if (r) 256 return r; 257 258 i2c_dw_disable_int(dev); 259 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 260 pdev->name, dev); 261 if (r) { 262 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 263 return r; 264 } 265 266 adap = &dev->adapter; 267 i2c_set_adapdata(adap, dev); 268 adap->owner = THIS_MODULE; 269 adap->class = I2C_CLASS_DEPRECATED; 270 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 271 sizeof(adap->name)); 272 adap->algo = &i2c_dw_algo; 273 adap->dev.parent = &pdev->dev; 274 adap->dev.of_node = pdev->dev.of_node; 275 276 if (dev->pm_runtime_disabled) { 277 pm_runtime_forbid(&pdev->dev); 278 } else { 279 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 280 pm_runtime_use_autosuspend(&pdev->dev); 281 pm_runtime_set_active(&pdev->dev); 282 pm_runtime_enable(&pdev->dev); 283 } 284 285 r = i2c_add_numbered_adapter(adap); 286 if (r) { 287 dev_err(&pdev->dev, "failure adding adapter\n"); 288 pm_runtime_disable(&pdev->dev); 289 return r; 290 } 291 292 return 0; 293 } 294 295 static int dw_i2c_remove(struct platform_device *pdev) 296 { 297 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 298 299 pm_runtime_get_sync(&pdev->dev); 300 301 i2c_del_adapter(&dev->adapter); 302 303 i2c_dw_disable(dev); 304 305 pm_runtime_dont_use_autosuspend(&pdev->dev); 306 pm_runtime_put_sync(&pdev->dev); 307 pm_runtime_disable(&pdev->dev); 308 309 if (has_acpi_companion(&pdev->dev)) 310 dw_i2c_acpi_unconfigure(pdev); 311 312 return 0; 313 } 314 315 #ifdef CONFIG_OF 316 static const struct of_device_id dw_i2c_of_match[] = { 317 { .compatible = "snps,designware-i2c", }, 318 {}, 319 }; 320 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 321 #endif 322 323 #ifdef CONFIG_PM_SLEEP 324 static int dw_i2c_prepare(struct device *dev) 325 { 326 return pm_runtime_suspended(dev); 327 } 328 329 static void dw_i2c_complete(struct device *dev) 330 { 331 if (dev->power.direct_complete) 332 pm_request_resume(dev); 333 } 334 #else 335 #define dw_i2c_prepare NULL 336 #define dw_i2c_complete NULL 337 #endif 338 339 #ifdef CONFIG_PM 340 static int dw_i2c_suspend(struct device *dev) 341 { 342 struct platform_device *pdev = to_platform_device(dev); 343 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 344 345 i2c_dw_disable(i_dev); 346 clk_disable_unprepare(i_dev->clk); 347 348 return 0; 349 } 350 351 static int dw_i2c_resume(struct device *dev) 352 { 353 struct platform_device *pdev = to_platform_device(dev); 354 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 355 356 clk_prepare_enable(i_dev->clk); 357 358 if (!i_dev->pm_runtime_disabled) 359 i2c_dw_init(i_dev); 360 361 return 0; 362 } 363 364 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 365 .prepare = dw_i2c_prepare, 366 .complete = dw_i2c_complete, 367 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume) 368 SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL) 369 }; 370 371 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 372 #else 373 #define DW_I2C_DEV_PMOPS NULL 374 #endif 375 376 /* work with hotplug and coldplug */ 377 MODULE_ALIAS("platform:i2c_designware"); 378 379 static struct platform_driver dw_i2c_driver = { 380 .probe = dw_i2c_probe, 381 .remove = dw_i2c_remove, 382 .driver = { 383 .name = "i2c_designware", 384 .of_match_table = of_match_ptr(dw_i2c_of_match), 385 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 386 .pm = DW_I2C_DEV_PMOPS, 387 }, 388 }; 389 390 static int __init dw_i2c_init_driver(void) 391 { 392 return platform_driver_register(&dw_i2c_driver); 393 } 394 subsys_initcall(dw_i2c_init_driver); 395 396 static void __exit dw_i2c_exit_driver(void) 397 { 398 platform_driver_unregister(&dw_i2c_driver); 399 } 400 module_exit(dw_i2c_exit_driver); 401 402 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 403 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 404 MODULE_LICENSE("GPL"); 405