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/property.h> 40 #include <linux/io.h> 41 #include <linux/reset.h> 42 #include <linux/slab.h> 43 #include <linux/acpi.h> 44 #include <linux/platform_data/i2c-designware.h> 45 #include "i2c-designware-core.h" 46 47 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 48 { 49 return clk_get_rate(dev->clk)/1000; 50 } 51 52 #ifdef CONFIG_ACPI 53 /* 54 * The HCNT/LCNT information coming from ACPI should be the most accurate 55 * for given platform. However, some systems get it wrong. On such systems 56 * we get better results by calculating those based on the input clock. 57 */ 58 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 59 { 60 .ident = "Dell Inspiron 7348", 61 .matches = { 62 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 63 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 64 }, 65 }, 66 { } 67 }; 68 69 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 70 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 71 { 72 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 73 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 74 union acpi_object *obj; 75 76 if (dmi_check_system(dw_i2c_no_acpi_params)) 77 return; 78 79 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 80 return; 81 82 obj = (union acpi_object *)buf.pointer; 83 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 84 const union acpi_object *objs = obj->package.elements; 85 86 *hcnt = (u16)objs[0].integer.value; 87 *lcnt = (u16)objs[1].integer.value; 88 if (sda_hold) 89 *sda_hold = (u32)objs[2].integer.value; 90 } 91 92 kfree(buf.pointer); 93 } 94 95 static int dw_i2c_acpi_configure(struct platform_device *pdev) 96 { 97 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 98 const struct acpi_device_id *id; 99 100 dev->adapter.nr = -1; 101 dev->tx_fifo_depth = 32; 102 dev->rx_fifo_depth = 32; 103 104 /* 105 * Try to get SDA hold time and *CNT values from an ACPI method if 106 * it exists for both supported speed modes. 107 */ 108 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 109 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 110 &dev->sda_hold_time); 111 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL); 112 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL); 113 114 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 115 if (id && id->driver_data) 116 dev->accessor_flags |= (u32)id->driver_data; 117 118 return 0; 119 } 120 121 static const struct acpi_device_id dw_i2c_acpi_match[] = { 122 { "INT33C2", 0 }, 123 { "INT33C3", 0 }, 124 { "INT3432", 0 }, 125 { "INT3433", 0 }, 126 { "80860F41", 0 }, 127 { "808622C1", 0 }, 128 { "AMD0010", ACCESS_INTR_MASK }, 129 { "AMDI0010", ACCESS_INTR_MASK }, 130 { "AMDI0510", 0 }, 131 { "APMC0D0F", 0 }, 132 { } 133 }; 134 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 135 #else 136 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 137 { 138 return -ENODEV; 139 } 140 #endif 141 142 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) 143 { 144 if (IS_ERR(i_dev->clk)) 145 return PTR_ERR(i_dev->clk); 146 147 if (prepare) 148 return clk_prepare_enable(i_dev->clk); 149 150 clk_disable_unprepare(i_dev->clk); 151 return 0; 152 } 153 154 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 155 { 156 u32 param, tx_fifo_depth, rx_fifo_depth; 157 158 /* 159 * Try to detect the FIFO depth if not set by interface driver, 160 * the depth could be from 2 to 256 from HW spec. 161 */ 162 param = i2c_dw_read_comp_param(dev); 163 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 164 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 165 if (!dev->tx_fifo_depth) { 166 dev->tx_fifo_depth = tx_fifo_depth; 167 dev->rx_fifo_depth = rx_fifo_depth; 168 dev->adapter.nr = id; 169 } else if (tx_fifo_depth >= 2) { 170 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 171 tx_fifo_depth); 172 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 173 rx_fifo_depth); 174 } 175 } 176 177 static int dw_i2c_plat_probe(struct platform_device *pdev) 178 { 179 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 180 struct dw_i2c_dev *dev; 181 struct i2c_adapter *adap; 182 struct resource *mem; 183 int irq, r; 184 u32 acpi_speed, ht = 0; 185 186 irq = platform_get_irq(pdev, 0); 187 if (irq < 0) 188 return irq; 189 190 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 191 if (!dev) 192 return -ENOMEM; 193 194 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 195 dev->base = devm_ioremap_resource(&pdev->dev, mem); 196 if (IS_ERR(dev->base)) 197 return PTR_ERR(dev->base); 198 199 dev->dev = &pdev->dev; 200 dev->irq = irq; 201 platform_set_drvdata(pdev, dev); 202 203 dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL); 204 if (IS_ERR(dev->rst)) { 205 if (PTR_ERR(dev->rst) == -EPROBE_DEFER) 206 return -EPROBE_DEFER; 207 } else { 208 reset_control_deassert(dev->rst); 209 } 210 211 if (pdata) { 212 dev->clk_freq = pdata->i2c_scl_freq; 213 } else { 214 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 215 &ht); 216 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 217 &dev->sda_falling_time); 218 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 219 &dev->scl_falling_time); 220 device_property_read_u32(&pdev->dev, "clock-frequency", 221 &dev->clk_freq); 222 } 223 224 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 225 /* 226 * Find bus speed from the "clock-frequency" device property, ACPI 227 * or by using fast mode if neither is set. 228 */ 229 if (acpi_speed && dev->clk_freq) 230 dev->clk_freq = min(dev->clk_freq, acpi_speed); 231 else if (acpi_speed || dev->clk_freq) 232 dev->clk_freq = max(dev->clk_freq, acpi_speed); 233 else 234 dev->clk_freq = 400000; 235 236 if (has_acpi_companion(&pdev->dev)) 237 dw_i2c_acpi_configure(pdev); 238 239 /* 240 * Only standard mode at 100kHz, fast mode at 400kHz, 241 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 242 */ 243 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 244 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 245 dev_err(&pdev->dev, 246 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); 247 r = -EINVAL; 248 goto exit_reset; 249 } 250 251 r = i2c_dw_eval_lock_support(dev); 252 if (r) 253 goto exit_reset; 254 255 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 256 257 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 258 DW_IC_CON_RESTART_EN; 259 260 switch (dev->clk_freq) { 261 case 100000: 262 dev->master_cfg |= DW_IC_CON_SPEED_STD; 263 break; 264 case 3400000: 265 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 266 break; 267 default: 268 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 269 } 270 271 dev->clk = devm_clk_get(&pdev->dev, NULL); 272 if (!i2c_dw_plat_prepare_clk(dev, true)) { 273 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 274 275 if (!dev->sda_hold_time && ht) 276 dev->sda_hold_time = div_u64( 277 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 278 1000000); 279 } 280 281 dw_i2c_set_fifo_size(dev, pdev->id); 282 283 adap = &dev->adapter; 284 adap->owner = THIS_MODULE; 285 adap->class = I2C_CLASS_DEPRECATED; 286 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 287 adap->dev.of_node = pdev->dev.of_node; 288 289 if (dev->pm_runtime_disabled) { 290 pm_runtime_forbid(&pdev->dev); 291 } else { 292 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 293 pm_runtime_use_autosuspend(&pdev->dev); 294 pm_runtime_set_active(&pdev->dev); 295 pm_runtime_enable(&pdev->dev); 296 } 297 298 r = i2c_dw_probe(dev); 299 if (r) 300 goto exit_probe; 301 302 return r; 303 304 exit_probe: 305 if (!dev->pm_runtime_disabled) 306 pm_runtime_disable(&pdev->dev); 307 exit_reset: 308 if (!IS_ERR_OR_NULL(dev->rst)) 309 reset_control_assert(dev->rst); 310 return r; 311 } 312 313 static int dw_i2c_plat_remove(struct platform_device *pdev) 314 { 315 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 316 317 pm_runtime_get_sync(&pdev->dev); 318 319 i2c_del_adapter(&dev->adapter); 320 321 i2c_dw_disable(dev); 322 323 pm_runtime_dont_use_autosuspend(&pdev->dev); 324 pm_runtime_put_sync(&pdev->dev); 325 if (!dev->pm_runtime_disabled) 326 pm_runtime_disable(&pdev->dev); 327 if (!IS_ERR_OR_NULL(dev->rst)) 328 reset_control_assert(dev->rst); 329 330 return 0; 331 } 332 333 #ifdef CONFIG_OF 334 static const struct of_device_id dw_i2c_of_match[] = { 335 { .compatible = "snps,designware-i2c", }, 336 {}, 337 }; 338 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 339 #endif 340 341 #ifdef CONFIG_PM_SLEEP 342 static int dw_i2c_plat_prepare(struct device *dev) 343 { 344 return pm_runtime_suspended(dev); 345 } 346 347 static void dw_i2c_plat_complete(struct device *dev) 348 { 349 if (dev->power.direct_complete) 350 pm_request_resume(dev); 351 } 352 #else 353 #define dw_i2c_plat_prepare NULL 354 #define dw_i2c_plat_complete NULL 355 #endif 356 357 #ifdef CONFIG_PM 358 static int dw_i2c_plat_suspend(struct device *dev) 359 { 360 struct platform_device *pdev = to_platform_device(dev); 361 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 362 363 i2c_dw_disable(i_dev); 364 i2c_dw_plat_prepare_clk(i_dev, false); 365 366 return 0; 367 } 368 369 static int dw_i2c_plat_resume(struct device *dev) 370 { 371 struct platform_device *pdev = to_platform_device(dev); 372 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 373 374 i2c_dw_plat_prepare_clk(i_dev, true); 375 376 if (!i_dev->pm_runtime_disabled) 377 i2c_dw_init(i_dev); 378 379 return 0; 380 } 381 382 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 383 .prepare = dw_i2c_plat_prepare, 384 .complete = dw_i2c_plat_complete, 385 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 386 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 387 }; 388 389 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 390 #else 391 #define DW_I2C_DEV_PMOPS NULL 392 #endif 393 394 /* work with hotplug and coldplug */ 395 MODULE_ALIAS("platform:i2c_designware"); 396 397 static struct platform_driver dw_i2c_driver = { 398 .probe = dw_i2c_plat_probe, 399 .remove = dw_i2c_plat_remove, 400 .driver = { 401 .name = "i2c_designware", 402 .of_match_table = of_match_ptr(dw_i2c_of_match), 403 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 404 .pm = DW_I2C_DEV_PMOPS, 405 }, 406 }; 407 408 static int __init dw_i2c_init_driver(void) 409 { 410 return platform_driver_register(&dw_i2c_driver); 411 } 412 subsys_initcall(dw_i2c_init_driver); 413 414 static void __exit dw_i2c_exit_driver(void) 415 { 416 platform_driver_unregister(&dw_i2c_driver); 417 } 418 module_exit(dw_i2c_exit_driver); 419 420 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 421 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 422 MODULE_LICENSE("GPL"); 423