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