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 /* fast mode by default because of legacy reasons */ 180 dev->clk_freq = 400000; 181 182 if (pdata) { 183 dev->clk_freq = pdata->i2c_scl_freq; 184 } else { 185 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 186 &ht); 187 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 188 &dev->sda_falling_time); 189 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 190 &dev->scl_falling_time); 191 device_property_read_u32(&pdev->dev, "clock-frequency", 192 &dev->clk_freq); 193 } 194 195 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); 196 if (acpi_speed) 197 dev->clk_freq = acpi_speed; 198 199 if (has_acpi_companion(&pdev->dev)) 200 dw_i2c_acpi_configure(pdev); 201 202 /* 203 * Only standard mode at 100kHz, fast mode at 400kHz, 204 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported. 205 */ 206 if (dev->clk_freq != 100000 && dev->clk_freq != 400000 207 && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) { 208 dev_err(&pdev->dev, 209 "Only 100kHz, 400kHz, 1MHz and 3.4MHz supported"); 210 return -EINVAL; 211 } 212 213 r = i2c_dw_eval_lock_support(dev); 214 if (r) 215 return r; 216 217 dev->functionality = 218 I2C_FUNC_I2C | 219 I2C_FUNC_10BIT_ADDR | 220 I2C_FUNC_SMBUS_BYTE | 221 I2C_FUNC_SMBUS_BYTE_DATA | 222 I2C_FUNC_SMBUS_WORD_DATA | 223 I2C_FUNC_SMBUS_I2C_BLOCK; 224 225 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 226 DW_IC_CON_RESTART_EN; 227 228 switch (dev->clk_freq) { 229 case 100000: 230 dev->master_cfg |= DW_IC_CON_SPEED_STD; 231 break; 232 case 3400000: 233 dev->master_cfg |= DW_IC_CON_SPEED_HIGH; 234 break; 235 default: 236 dev->master_cfg |= DW_IC_CON_SPEED_FAST; 237 } 238 239 dev->clk = devm_clk_get(&pdev->dev, NULL); 240 if (!i2c_dw_plat_prepare_clk(dev, true)) { 241 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 242 243 if (!dev->sda_hold_time && ht) 244 dev->sda_hold_time = div_u64( 245 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 246 1000000); 247 } 248 249 if (!dev->tx_fifo_depth) { 250 u32 param1 = i2c_dw_read_comp_param(dev); 251 252 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 253 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 254 dev->adapter.nr = pdev->id; 255 } 256 257 adap = &dev->adapter; 258 adap->owner = THIS_MODULE; 259 adap->class = I2C_CLASS_DEPRECATED; 260 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 261 adap->dev.of_node = pdev->dev.of_node; 262 263 if (dev->pm_runtime_disabled) { 264 pm_runtime_forbid(&pdev->dev); 265 } else { 266 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 267 pm_runtime_use_autosuspend(&pdev->dev); 268 pm_runtime_set_active(&pdev->dev); 269 pm_runtime_enable(&pdev->dev); 270 } 271 272 r = i2c_dw_probe(dev); 273 if (r && !dev->pm_runtime_disabled) 274 pm_runtime_disable(&pdev->dev); 275 276 return r; 277 } 278 279 static int dw_i2c_plat_remove(struct platform_device *pdev) 280 { 281 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 282 283 pm_runtime_get_sync(&pdev->dev); 284 285 i2c_del_adapter(&dev->adapter); 286 287 i2c_dw_disable(dev); 288 289 pm_runtime_dont_use_autosuspend(&pdev->dev); 290 pm_runtime_put_sync(&pdev->dev); 291 if (!dev->pm_runtime_disabled) 292 pm_runtime_disable(&pdev->dev); 293 294 return 0; 295 } 296 297 #ifdef CONFIG_OF 298 static const struct of_device_id dw_i2c_of_match[] = { 299 { .compatible = "snps,designware-i2c", }, 300 {}, 301 }; 302 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 303 #endif 304 305 #ifdef CONFIG_PM_SLEEP 306 static int dw_i2c_plat_prepare(struct device *dev) 307 { 308 return pm_runtime_suspended(dev); 309 } 310 311 static void dw_i2c_plat_complete(struct device *dev) 312 { 313 if (dev->power.direct_complete) 314 pm_request_resume(dev); 315 } 316 #else 317 #define dw_i2c_plat_prepare NULL 318 #define dw_i2c_plat_complete NULL 319 #endif 320 321 #ifdef CONFIG_PM 322 static int dw_i2c_plat_suspend(struct device *dev) 323 { 324 struct platform_device *pdev = to_platform_device(dev); 325 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 326 327 i2c_dw_disable(i_dev); 328 i2c_dw_plat_prepare_clk(i_dev, false); 329 330 return 0; 331 } 332 333 static int dw_i2c_plat_resume(struct device *dev) 334 { 335 struct platform_device *pdev = to_platform_device(dev); 336 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 337 338 i2c_dw_plat_prepare_clk(i_dev, true); 339 340 if (!i_dev->pm_runtime_disabled) 341 i2c_dw_init(i_dev); 342 343 return 0; 344 } 345 346 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 347 .prepare = dw_i2c_plat_prepare, 348 .complete = dw_i2c_plat_complete, 349 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 350 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 351 }; 352 353 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 354 #else 355 #define DW_I2C_DEV_PMOPS NULL 356 #endif 357 358 /* work with hotplug and coldplug */ 359 MODULE_ALIAS("platform:i2c_designware"); 360 361 static struct platform_driver dw_i2c_driver = { 362 .probe = dw_i2c_plat_probe, 363 .remove = dw_i2c_plat_remove, 364 .driver = { 365 .name = "i2c_designware", 366 .of_match_table = of_match_ptr(dw_i2c_of_match), 367 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 368 .pm = DW_I2C_DEV_PMOPS, 369 }, 370 }; 371 372 static int __init dw_i2c_init_driver(void) 373 { 374 return platform_driver_register(&dw_i2c_driver); 375 } 376 subsys_initcall(dw_i2c_init_driver); 377 378 static void __exit dw_i2c_exit_driver(void) 379 { 380 platform_driver_unregister(&dw_i2c_driver); 381 } 382 module_exit(dw_i2c_exit_driver); 383 384 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 385 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 386 MODULE_LICENSE("GPL"); 387