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 int dw_i2c_plat_probe(struct platform_device *pdev) 154 { 155 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 156 struct dw_i2c_dev *dev; 157 struct i2c_adapter *adap; 158 struct resource *mem; 159 int irq, r; 160 u32 acpi_speed, ht = 0; 161 162 irq = platform_get_irq(pdev, 0); 163 if (irq < 0) 164 return irq; 165 166 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 167 if (!dev) 168 return -ENOMEM; 169 170 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 171 dev->base = devm_ioremap_resource(&pdev->dev, mem); 172 if (IS_ERR(dev->base)) 173 return PTR_ERR(dev->base); 174 175 dev->dev = &pdev->dev; 176 dev->irq = irq; 177 platform_set_drvdata(pdev, dev); 178 179 if (pdata) { 180 dev->clk_freq = pdata->i2c_scl_freq; 181 } else { 182 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 183 &ht); 184 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 185 &dev->sda_falling_time); 186 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 187 &dev->scl_falling_time); 188 device_property_read_u32(&pdev->dev, "clock-frequency", 189 &dev->clk_freq); 190 } 191 192 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 193 /* 194 * Find bus speed from the "clock-frequency" device property, ACPI 195 * or by using fast mode if neither is set. 196 */ 197 if (acpi_speed && dev->clk_freq) 198 dev->clk_freq = min(dev->clk_freq, acpi_speed); 199 else if (acpi_speed || dev->clk_freq) 200 dev->clk_freq = max(dev->clk_freq, acpi_speed); 201 else 202 dev->clk_freq = 400000; 203 204 if (has_acpi_companion(&pdev->dev)) 205 dw_i2c_acpi_configure(pdev); 206 207 /* 208 * Only standard mode at 100kHz, fast mode at 400kHz, 209 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 210 */ 211 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 212 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 213 dev_err(&pdev->dev, 214 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); 215 return -EINVAL; 216 } 217 218 r = i2c_dw_eval_lock_support(dev); 219 if (r) 220 return r; 221 222 dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; 223 224 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 225 DW_IC_CON_RESTART_EN; 226 227 switch (dev->clk_freq) { 228 case 100000: 229 dev->master_cfg |= DW_IC_CON_SPEED_STD; 230 break; 231 case 3400000: 232 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 233 break; 234 default: 235 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 236 } 237 238 dev->clk = devm_clk_get(&pdev->dev, NULL); 239 if (!i2c_dw_plat_prepare_clk(dev, true)) { 240 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 241 242 if (!dev->sda_hold_time && ht) 243 dev->sda_hold_time = div_u64( 244 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 245 1000000); 246 } 247 248 if (!dev->tx_fifo_depth) { 249 u32 param1 = i2c_dw_read_comp_param(dev); 250 251 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 252 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 253 dev->adapter.nr = pdev->id; 254 } 255 256 adap = &dev->adapter; 257 adap->owner = THIS_MODULE; 258 adap->class = I2C_CLASS_DEPRECATED; 259 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 260 adap->dev.of_node = pdev->dev.of_node; 261 262 if (dev->pm_runtime_disabled) { 263 pm_runtime_forbid(&pdev->dev); 264 } else { 265 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 266 pm_runtime_use_autosuspend(&pdev->dev); 267 pm_runtime_set_active(&pdev->dev); 268 pm_runtime_enable(&pdev->dev); 269 } 270 271 r = i2c_dw_probe(dev); 272 if (r && !dev->pm_runtime_disabled) 273 pm_runtime_disable(&pdev->dev); 274 275 return r; 276 } 277 278 static int dw_i2c_plat_remove(struct platform_device *pdev) 279 { 280 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 281 282 pm_runtime_get_sync(&pdev->dev); 283 284 i2c_del_adapter(&dev->adapter); 285 286 i2c_dw_disable(dev); 287 288 pm_runtime_dont_use_autosuspend(&pdev->dev); 289 pm_runtime_put_sync(&pdev->dev); 290 if (!dev->pm_runtime_disabled) 291 pm_runtime_disable(&pdev->dev); 292 293 return 0; 294 } 295 296 #ifdef CONFIG_OF 297 static const struct of_device_id dw_i2c_of_match[] = { 298 { .compatible = "snps,designware-i2c", }, 299 {}, 300 }; 301 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 302 #endif 303 304 #ifdef CONFIG_PM_SLEEP 305 static int dw_i2c_plat_prepare(struct device *dev) 306 { 307 return pm_runtime_suspended(dev); 308 } 309 310 static void dw_i2c_plat_complete(struct device *dev) 311 { 312 if (dev->power.direct_complete) 313 pm_request_resume(dev); 314 } 315 #else 316 #define dw_i2c_plat_prepare NULL 317 #define dw_i2c_plat_complete NULL 318 #endif 319 320 #ifdef CONFIG_PM 321 static int dw_i2c_plat_suspend(struct device *dev) 322 { 323 struct platform_device *pdev = to_platform_device(dev); 324 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 325 326 i2c_dw_disable(i_dev); 327 i2c_dw_plat_prepare_clk(i_dev, false); 328 329 return 0; 330 } 331 332 static int dw_i2c_plat_resume(struct device *dev) 333 { 334 struct platform_device *pdev = to_platform_device(dev); 335 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 336 337 i2c_dw_plat_prepare_clk(i_dev, true); 338 339 if (!i_dev->pm_runtime_disabled) 340 i2c_dw_init(i_dev); 341 342 return 0; 343 } 344 345 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 346 .prepare = dw_i2c_plat_prepare, 347 .complete = dw_i2c_plat_complete, 348 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 349 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 350 }; 351 352 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 353 #else 354 #define DW_I2C_DEV_PMOPS NULL 355 #endif 356 357 /* work with hotplug and coldplug */ 358 MODULE_ALIAS("platform:i2c_designware"); 359 360 static struct platform_driver dw_i2c_driver = { 361 .probe = dw_i2c_plat_probe, 362 .remove = dw_i2c_plat_remove, 363 .driver = { 364 .name = "i2c_designware", 365 .of_match_table = of_match_ptr(dw_i2c_of_match), 366 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 367 .pm = DW_I2C_DEV_PMOPS, 368 }, 369 }; 370 371 static int __init dw_i2c_init_driver(void) 372 { 373 return platform_driver_register(&dw_i2c_driver); 374 } 375 subsys_initcall(dw_i2c_init_driver); 376 377 static void __exit dw_i2c_exit_driver(void) 378 { 379 platform_driver_unregister(&dw_i2c_driver); 380 } 381 module_exit(dw_i2c_exit_driver); 382 383 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 384 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 385 MODULE_LICENSE("GPL"); 386