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); 110 111 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 112 if (id && id->driver_data) 113 dev->accessor_flags |= (u32)id->driver_data; 114 115 return 0; 116 } 117 118 static const struct acpi_device_id dw_i2c_acpi_match[] = { 119 { "INT33C2", 0 }, 120 { "INT33C3", 0 }, 121 { "INT3432", 0 }, 122 { "INT3433", 0 }, 123 { "80860F41", 0 }, 124 { "808622C1", 0 }, 125 { "AMD0010", ACCESS_INTR_MASK }, 126 { "AMDI0010", ACCESS_INTR_MASK }, 127 { "AMDI0510", 0 }, 128 { "APMC0D0F", 0 }, 129 { } 130 }; 131 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 132 #else 133 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 134 { 135 return -ENODEV; 136 } 137 #endif 138 139 static int i2c_dw_plat_prepare_clk(struct dw_i2c_dev *i_dev, bool prepare) 140 { 141 if (IS_ERR(i_dev->clk)) 142 return PTR_ERR(i_dev->clk); 143 144 if (prepare) 145 return clk_prepare_enable(i_dev->clk); 146 147 clk_disable_unprepare(i_dev->clk); 148 return 0; 149 } 150 151 static int dw_i2c_plat_probe(struct platform_device *pdev) 152 { 153 struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev); 154 struct dw_i2c_dev *dev; 155 struct i2c_adapter *adap; 156 struct resource *mem; 157 int irq, r; 158 u32 clk_freq, ht = 0; 159 160 irq = platform_get_irq(pdev, 0); 161 if (irq < 0) 162 return irq; 163 164 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 165 if (!dev) 166 return -ENOMEM; 167 168 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 169 dev->base = devm_ioremap_resource(&pdev->dev, mem); 170 if (IS_ERR(dev->base)) 171 return PTR_ERR(dev->base); 172 173 dev->dev = &pdev->dev; 174 dev->irq = irq; 175 platform_set_drvdata(pdev, dev); 176 177 /* fast mode by default because of legacy reasons */ 178 clk_freq = 400000; 179 180 if (pdata) { 181 clk_freq = pdata->i2c_scl_freq; 182 } else { 183 device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns", 184 &ht); 185 device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns", 186 &dev->sda_falling_time); 187 device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns", 188 &dev->scl_falling_time); 189 device_property_read_u32(&pdev->dev, "clock-frequency", 190 &clk_freq); 191 } 192 193 if (has_acpi_companion(&pdev->dev)) 194 dw_i2c_acpi_configure(pdev); 195 196 /* 197 * Only standard mode at 100kHz and fast mode at 400kHz are supported. 198 */ 199 if (clk_freq != 100000 && clk_freq != 400000) { 200 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 201 return -EINVAL; 202 } 203 204 r = i2c_dw_eval_lock_support(dev); 205 if (r) 206 return r; 207 208 dev->functionality = 209 I2C_FUNC_I2C | 210 I2C_FUNC_10BIT_ADDR | 211 I2C_FUNC_SMBUS_BYTE | 212 I2C_FUNC_SMBUS_BYTE_DATA | 213 I2C_FUNC_SMBUS_WORD_DATA | 214 I2C_FUNC_SMBUS_I2C_BLOCK; 215 if (clk_freq == 100000) 216 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 217 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 218 else 219 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 220 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 221 222 dev->clk = devm_clk_get(&pdev->dev, NULL); 223 if (!i2c_dw_plat_prepare_clk(dev, true)) { 224 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 225 226 if (!dev->sda_hold_time && ht) 227 dev->sda_hold_time = div_u64( 228 (u64)dev->get_clk_rate_khz(dev) * ht + 500000, 229 1000000); 230 } 231 232 if (!dev->tx_fifo_depth) { 233 u32 param1 = i2c_dw_read_comp_param(dev); 234 235 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 236 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 237 dev->adapter.nr = pdev->id; 238 } 239 240 adap = &dev->adapter; 241 adap->owner = THIS_MODULE; 242 adap->class = I2C_CLASS_DEPRECATED; 243 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 244 adap->dev.of_node = pdev->dev.of_node; 245 246 if (dev->pm_runtime_disabled) { 247 pm_runtime_forbid(&pdev->dev); 248 } else { 249 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 250 pm_runtime_use_autosuspend(&pdev->dev); 251 pm_runtime_set_active(&pdev->dev); 252 pm_runtime_enable(&pdev->dev); 253 } 254 255 r = i2c_dw_probe(dev); 256 if (r && !dev->pm_runtime_disabled) 257 pm_runtime_disable(&pdev->dev); 258 259 return r; 260 } 261 262 static int dw_i2c_plat_remove(struct platform_device *pdev) 263 { 264 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 265 266 pm_runtime_get_sync(&pdev->dev); 267 268 i2c_del_adapter(&dev->adapter); 269 270 i2c_dw_disable(dev); 271 272 pm_runtime_dont_use_autosuspend(&pdev->dev); 273 pm_runtime_put_sync(&pdev->dev); 274 if (!dev->pm_runtime_disabled) 275 pm_runtime_disable(&pdev->dev); 276 277 return 0; 278 } 279 280 #ifdef CONFIG_OF 281 static const struct of_device_id dw_i2c_of_match[] = { 282 { .compatible = "snps,designware-i2c", }, 283 {}, 284 }; 285 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 286 #endif 287 288 #ifdef CONFIG_PM_SLEEP 289 static int dw_i2c_plat_prepare(struct device *dev) 290 { 291 return pm_runtime_suspended(dev); 292 } 293 294 static void dw_i2c_plat_complete(struct device *dev) 295 { 296 if (dev->power.direct_complete) 297 pm_request_resume(dev); 298 } 299 #else 300 #define dw_i2c_plat_prepare NULL 301 #define dw_i2c_plat_complete NULL 302 #endif 303 304 #ifdef CONFIG_PM 305 static int dw_i2c_plat_suspend(struct device *dev) 306 { 307 struct platform_device *pdev = to_platform_device(dev); 308 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 309 310 i2c_dw_disable(i_dev); 311 i2c_dw_plat_prepare_clk(i_dev, false); 312 313 return 0; 314 } 315 316 static int dw_i2c_plat_resume(struct device *dev) 317 { 318 struct platform_device *pdev = to_platform_device(dev); 319 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 320 321 i2c_dw_plat_prepare_clk(i_dev, true); 322 323 if (!i_dev->pm_runtime_disabled) 324 i2c_dw_init(i_dev); 325 326 return 0; 327 } 328 329 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 330 .prepare = dw_i2c_plat_prepare, 331 .complete = dw_i2c_plat_complete, 332 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 333 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 334 }; 335 336 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 337 #else 338 #define DW_I2C_DEV_PMOPS NULL 339 #endif 340 341 /* work with hotplug and coldplug */ 342 MODULE_ALIAS("platform:i2c_designware"); 343 344 static struct platform_driver dw_i2c_driver = { 345 .probe = dw_i2c_plat_probe, 346 .remove = dw_i2c_plat_remove, 347 .driver = { 348 .name = "i2c_designware", 349 .of_match_table = of_match_ptr(dw_i2c_of_match), 350 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 351 .pm = DW_I2C_DEV_PMOPS, 352 }, 353 }; 354 355 static int __init dw_i2c_init_driver(void) 356 { 357 return platform_driver_register(&dw_i2c_driver); 358 } 359 subsys_initcall(dw_i2c_init_driver); 360 361 static void __exit dw_i2c_exit_driver(void) 362 { 363 platform_driver_unregister(&dw_i2c_driver); 364 } 365 module_exit(dw_i2c_exit_driver); 366 367 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 368 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 369 MODULE_LICENSE("GPL"); 370