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/slab.h> 42 #include <linux/acpi.h> 43 #include <linux/platform_data/i2c-designware.h> 44 #include "i2c-designware-core.h" 45 46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 47 { 48 return clk_get_rate(dev->clk)/1000; 49 } 50 51 #ifdef CONFIG_ACPI 52 /* 53 * The HCNT/LCNT information coming from ACPI should be the most accurate 54 * for given platform. However, some systems get it wrong. On such systems 55 * we get better results by calculating those based on the input clock. 56 */ 57 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 58 { 59 .ident = "Dell Inspiron 7348", 60 .matches = { 61 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 62 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 63 }, 64 }, 65 { } 66 }; 67 68 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 69 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 70 { 71 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 72 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 73 union acpi_object *obj; 74 75 if (dmi_check_system(dw_i2c_no_acpi_params)) 76 return; 77 78 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 79 return; 80 81 obj = (union acpi_object *)buf.pointer; 82 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 83 const union acpi_object *objs = obj->package.elements; 84 85 *hcnt = (u16)objs[0].integer.value; 86 *lcnt = (u16)objs[1].integer.value; 87 if (sda_hold) 88 *sda_hold = (u32)objs[2].integer.value; 89 } 90 91 kfree(buf.pointer); 92 } 93 94 static int dw_i2c_acpi_configure(struct platform_device *pdev) 95 { 96 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 97 const struct acpi_device_id *id; 98 99 dev->adapter.nr = -1; 100 dev->tx_fifo_depth = 32; 101 dev->rx_fifo_depth = 32; 102 103 /* 104 * Try to get SDA hold time and *CNT values from an ACPI method if 105 * it exists for both supported speed modes. 106 */ 107 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 108 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 109 &dev->sda_hold_time); 110 dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, &dev->fp_lcnt, NULL); 111 dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, NULL); 112 113 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 114 if (id && id->driver_data) 115 dev->accessor_flags |= (u32)id->driver_data; 116 117 return 0; 118 } 119 120 static const struct acpi_device_id dw_i2c_acpi_match[] = { 121 { "INT33C2", 0 }, 122 { "INT33C3", 0 }, 123 { "INT3432", 0 }, 124 { "INT3433", 0 }, 125 { "80860F41", 0 }, 126 { "808622C1", 0 }, 127 { "AMD0010", ACCESS_INTR_MASK }, 128 { "AMDI0010", ACCESS_INTR_MASK }, 129 { "AMDI0510", 0 }, 130 { "APMC0D0F", 0 }, 131 { } 132 }; 133 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 134 #else 135 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 136 { 137 return -ENODEV; 138 } 139 #endif 140 141 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) 142 { 143 if (IS_ERR(i_dev->clk)) 144 return PTR_ERR(i_dev->clk); 145 146 if (prepare) 147 return clk_prepare_enable(i_dev->clk); 148 149 clk_disable_unprepare(i_dev->clk); 150 return 0; 151 } 152 153 static void dw_i2c_set_fifo_size(struct dw_i2c_dev *dev, int id) 154 { 155 u32 param, tx_fifo_depth, rx_fifo_depth; 156 157 /* 158 * Try to detect the FIFO depth if not set by interface driver, 159 * the depth could be from 2 to 256 from HW spec. 160 */ 161 param = i2c_dw_read_comp_param(dev); 162 tx_fifo_depth = ((param >> 16) & 0xff) + 1; 163 rx_fifo_depth = ((param >> 8) & 0xff) + 1; 164 if (!dev->tx_fifo_depth) { 165 dev->tx_fifo_depth = tx_fifo_depth; 166 dev->rx_fifo_depth = rx_fifo_depth; 167 dev->adapter.nr = id; 168 } else if (tx_fifo_depth >= 2) { 169 dev->tx_fifo_depth = min_t(u32, dev->tx_fifo_depth, 170 tx_fifo_depth); 171 dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth, 172 rx_fifo_depth); 173 } 174 } 175 176 static int dw_i2c_plat_probe(struct platform_device *pdev) 177 { 178 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 179 struct dw_i2c_dev *dev; 180 struct i2c_adapter *adap; 181 struct resource *mem; 182 int irq, r; 183 u32 acpi_speed, ht = 0; 184 185 irq = platform_get_irq(pdev, 0); 186 if (irq < 0) 187 return irq; 188 189 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 190 if (!dev) 191 return -ENOMEM; 192 193 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 194 dev->base = devm_ioremap_resource(&pdev->dev, mem); 195 if (IS_ERR(dev->base)) 196 return PTR_ERR(dev->base); 197 198 dev->dev = &pdev->dev; 199 dev->irq = irq; 200 platform_set_drvdata(pdev, dev); 201 202 if (pdata) { 203 dev->clk_freq = pdata->i2c_scl_freq; 204 } else { 205 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 206 &ht); 207 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 208 &dev->sda_falling_time); 209 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 210 &dev->scl_falling_time); 211 device_property_read_u32(&pdev->dev, "clock-frequency", 212 &dev->clk_freq); 213 } 214 215 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 216 /* 217 * Find bus speed from the "clock-frequency" device property, ACPI 218 * or by using fast mode if neither is set. 219 */ 220 if (acpi_speed && dev->clk_freq) 221 dev->clk_freq = min(dev->clk_freq, acpi_speed); 222 else if (acpi_speed || dev->clk_freq) 223 dev->clk_freq = max(dev->clk_freq, acpi_speed); 224 else 225 dev->clk_freq = 400000; 226 227 if (has_acpi_companion(&pdev->dev)) 228 dw_i2c_acpi_configure(pdev); 229 230 /* 231 * Only standard mode at 100kHz, fast mode at 400kHz, 232 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 233 */ 234 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 235 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 236 dev_err(&pdev->dev, 237 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); 238 return -EINVAL; 239 } 240 241 r = i2c_dw_eval_lock_support(dev); 242 if (r) 243 return r; 244 245 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 246 247 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 248 DW_IC_CON_RESTART_EN; 249 250 switch (dev->clk_freq) { 251 case 100000: 252 dev->master_cfg |= DW_IC_CON_SPEED_STD; 253 break; 254 case 3400000: 255 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 256 break; 257 default: 258 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 259 } 260 261 dev->clk = devm_clk_get(&pdev->dev, NULL); 262 if (!i2c_dw_plat_prepare_clk(dev, true)) { 263 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 264 265 if (!dev->sda_hold_time && ht) 266 dev->sda_hold_time = div_u64( 267 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 268 1000000); 269 } 270 271 dw_i2c_set_fifo_size(dev, pdev->id); 272 273 adap = &dev->adapter; 274 adap->owner = THIS_MODULE; 275 adap->class = I2C_CLASS_DEPRECATED; 276 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 277 adap->dev.of_node = pdev->dev.of_node; 278 279 if (dev->pm_runtime_disabled) { 280 pm_runtime_forbid(&pdev->dev); 281 } else { 282 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 283 pm_runtime_use_autosuspend(&pdev->dev); 284 pm_runtime_set_active(&pdev->dev); 285 pm_runtime_enable(&pdev->dev); 286 } 287 288 r = i2c_dw_probe(dev); 289 if (r && !dev->pm_runtime_disabled) 290 pm_runtime_disable(&pdev->dev); 291 292 return r; 293 } 294 295 static int dw_i2c_plat_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 if (!dev->pm_runtime_disabled) 308 pm_runtime_disable(&pdev->dev); 309 310 return 0; 311 } 312 313 #ifdef CONFIG_OF 314 static const struct of_device_id dw_i2c_of_match[] = { 315 { .compatible = "snps,designware-i2c", }, 316 {}, 317 }; 318 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 319 #endif 320 321 #ifdef CONFIG_PM_SLEEP 322 static int dw_i2c_plat_prepare(struct device *dev) 323 { 324 return pm_runtime_suspended(dev); 325 } 326 327 static void dw_i2c_plat_complete(struct device *dev) 328 { 329 if (dev->power.direct_complete) 330 pm_request_resume(dev); 331 } 332 #else 333 #define dw_i2c_plat_prepare NULL 334 #define dw_i2c_plat_complete NULL 335 #endif 336 337 #ifdef CONFIG_PM 338 static int dw_i2c_plat_suspend(struct device *dev) 339 { 340 struct platform_device *pdev = to_platform_device(dev); 341 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 342 343 i2c_dw_disable(i_dev); 344 i2c_dw_plat_prepare_clk(i_dev, false); 345 346 return 0; 347 } 348 349 static int dw_i2c_plat_resume(struct device *dev) 350 { 351 struct platform_device *pdev = to_platform_device(dev); 352 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 353 354 i2c_dw_plat_prepare_clk(i_dev, true); 355 356 if (!i_dev->pm_runtime_disabled) 357 i2c_dw_init(i_dev); 358 359 return 0; 360 } 361 362 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 363 .prepare = dw_i2c_plat_prepare, 364 .complete = dw_i2c_plat_complete, 365 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 366 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 367 }; 368 369 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 370 #else 371 #define DW_I2C_DEV_PMOPS NULL 372 #endif 373 374 /* work with hotplug and coldplug */ 375 MODULE_ALIAS("platform:i2c_designware"); 376 377 static struct platform_driver dw_i2c_driver = { 378 .probe = dw_i2c_plat_probe, 379 .remove = dw_i2c_plat_remove, 380 .driver = { 381 .name = "i2c_designware", 382 .of_match_table = of_match_ptr(dw_i2c_of_match), 383 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 384 .pm = DW_I2C_DEV_PMOPS, 385 }, 386 }; 387 388 static int __init dw_i2c_init_driver(void) 389 { 390 return platform_driver_register(&dw_i2c_driver); 391 } 392 subsys_initcall(dw_i2c_init_driver); 393 394 static void __exit dw_i2c_exit_driver(void) 395 { 396 platform_driver_unregister(&dw_i2c_driver); 397 } 398 module_exit(dw_i2c_exit_driver); 399 400 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 401 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 402 MODULE_LICENSE("GPL"); 403