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/i2c.h> 28 #include <linux/clk.h> 29 #include <linux/clk-provider.h> 30 #include <linux/errno.h> 31 #include <linux/sched.h> 32 #include <linux/err.h> 33 #include <linux/interrupt.h> 34 #include <linux/of.h> 35 #include <linux/platform_device.h> 36 #include <linux/pm.h> 37 #include <linux/pm_runtime.h> 38 #include <linux/io.h> 39 #include <linux/slab.h> 40 #include <linux/acpi.h> 41 #include <linux/platform_data/i2c-designware.h> 42 #include "i2c-designware-core.h" 43 44 static struct i2c_algorithm i2c_dw_algo = { 45 .master_xfer = i2c_dw_xfer, 46 .functionality = i2c_dw_func, 47 }; 48 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 49 { 50 return clk_get_rate(dev->clk)/1000; 51 } 52 53 #ifdef CONFIG_ACPI 54 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 55 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 56 { 57 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 58 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 59 union acpi_object *obj; 60 61 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 62 return; 63 64 obj = (union acpi_object *)buf.pointer; 65 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 66 const union acpi_object *objs = obj->package.elements; 67 68 *hcnt = (u16)objs[0].integer.value; 69 *lcnt = (u16)objs[1].integer.value; 70 if (sda_hold) 71 *sda_hold = (u32)objs[2].integer.value; 72 } 73 74 kfree(buf.pointer); 75 } 76 77 static int dw_i2c_acpi_configure(struct platform_device *pdev) 78 { 79 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 80 const struct acpi_device_id *id; 81 82 dev->adapter.nr = -1; 83 dev->tx_fifo_depth = 32; 84 dev->rx_fifo_depth = 32; 85 86 /* 87 * Try to get SDA hold time and *CNT values from an ACPI method if 88 * it exists for both supported speed modes. 89 */ 90 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 91 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 92 &dev->sda_hold_time); 93 94 /* 95 * Provide a way for Designware I2C host controllers that are not 96 * based on Intel LPSS to specify their input clock frequency via 97 * id->driver_data. 98 */ 99 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 100 if (id && id->driver_data) 101 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL, 102 CLK_IS_ROOT, id->driver_data); 103 104 return 0; 105 } 106 107 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev) 108 { 109 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 110 const struct acpi_device_id *id; 111 112 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 113 if (id && id->driver_data) 114 clk_unregister(dev->clk); 115 } 116 117 static const struct acpi_device_id dw_i2c_acpi_match[] = { 118 { "INT33C2", 0 }, 119 { "INT33C3", 0 }, 120 { "INT3432", 0 }, 121 { "INT3433", 0 }, 122 { "80860F41", 0 }, 123 { "808622C1", 0 }, 124 { "AMD0010", 133 * 1000 * 1000 }, 125 { } 126 }; 127 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 128 #else 129 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 130 { 131 return -ENODEV; 132 } 133 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { } 134 #endif 135 136 static int dw_i2c_probe(struct platform_device *pdev) 137 { 138 struct dw_i2c_dev *dev; 139 struct i2c_adapter *adap; 140 struct resource *mem; 141 struct dw_i2c_platform_data *pdata; 142 int irq, r; 143 u32 clk_freq, ht = 0; 144 145 irq = platform_get_irq(pdev, 0); 146 if (irq < 0) 147 return irq; 148 149 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 150 if (!dev) 151 return -ENOMEM; 152 153 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 154 dev->base = devm_ioremap_resource(&pdev->dev, mem); 155 if (IS_ERR(dev->base)) 156 return PTR_ERR(dev->base); 157 158 init_completion(&dev->cmd_complete); 159 mutex_init(&dev->lock); 160 dev->dev = &pdev->dev; 161 dev->irq = irq; 162 platform_set_drvdata(pdev, dev); 163 164 /* fast mode by default because of legacy reasons */ 165 clk_freq = 400000; 166 167 if (has_acpi_companion(&pdev->dev)) { 168 dw_i2c_acpi_configure(pdev); 169 } else if (pdev->dev.of_node) { 170 of_property_read_u32(pdev->dev.of_node, 171 "i2c-sda-hold-time-ns", &ht); 172 173 of_property_read_u32(pdev->dev.of_node, 174 "i2c-sda-falling-time-ns", 175 &dev->sda_falling_time); 176 of_property_read_u32(pdev->dev.of_node, 177 "i2c-scl-falling-time-ns", 178 &dev->scl_falling_time); 179 180 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 181 &clk_freq); 182 183 /* Only standard mode at 100kHz and fast mode at 400kHz 184 * are supported. 185 */ 186 if (clk_freq != 100000 && clk_freq != 400000) { 187 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 188 return -EINVAL; 189 } 190 } else { 191 pdata = dev_get_platdata(&pdev->dev); 192 if (pdata) 193 clk_freq = pdata->i2c_scl_freq; 194 } 195 196 r = i2c_dw_eval_lock_support(dev); 197 if (r) 198 return r; 199 200 dev->functionality = 201 I2C_FUNC_I2C | 202 I2C_FUNC_10BIT_ADDR | 203 I2C_FUNC_SMBUS_BYTE | 204 I2C_FUNC_SMBUS_BYTE_DATA | 205 I2C_FUNC_SMBUS_WORD_DATA | 206 I2C_FUNC_SMBUS_I2C_BLOCK; 207 if (clk_freq == 100000) 208 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 209 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 210 else 211 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 212 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 213 214 dev->clk = devm_clk_get(&pdev->dev, NULL); 215 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 216 if (IS_ERR(dev->clk)) 217 return PTR_ERR(dev->clk); 218 clk_prepare_enable(dev->clk); 219 220 if (!dev->sda_hold_time && ht) { 221 u32 ic_clk = dev->get_clk_rate_khz(dev); 222 223 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 224 1000000); 225 } 226 227 if (!dev->tx_fifo_depth) { 228 u32 param1 = i2c_dw_read_comp_param(dev); 229 230 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 231 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 232 dev->adapter.nr = pdev->id; 233 } 234 r = i2c_dw_init(dev); 235 if (r) 236 return r; 237 238 i2c_dw_disable_int(dev); 239 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 240 pdev->name, dev); 241 if (r) { 242 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 243 return r; 244 } 245 246 adap = &dev->adapter; 247 i2c_set_adapdata(adap, dev); 248 adap->owner = THIS_MODULE; 249 adap->class = I2C_CLASS_DEPRECATED; 250 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 251 sizeof(adap->name)); 252 adap->algo = &i2c_dw_algo; 253 adap->dev.parent = &pdev->dev; 254 adap->dev.of_node = pdev->dev.of_node; 255 256 r = i2c_add_numbered_adapter(adap); 257 if (r) { 258 dev_err(&pdev->dev, "failure adding adapter\n"); 259 return r; 260 } 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 return 0; 272 } 273 274 static int dw_i2c_remove(struct platform_device *pdev) 275 { 276 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 277 278 pm_runtime_get_sync(&pdev->dev); 279 280 i2c_del_adapter(&dev->adapter); 281 282 i2c_dw_disable(dev); 283 284 pm_runtime_dont_use_autosuspend(&pdev->dev); 285 pm_runtime_put_sync(&pdev->dev); 286 pm_runtime_disable(&pdev->dev); 287 288 if (has_acpi_companion(&pdev->dev)) 289 dw_i2c_acpi_unconfigure(pdev); 290 291 return 0; 292 } 293 294 #ifdef CONFIG_OF 295 static const struct of_device_id dw_i2c_of_match[] = { 296 { .compatible = "snps,designware-i2c", }, 297 {}, 298 }; 299 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 300 #endif 301 302 #ifdef CONFIG_PM_SLEEP 303 static int dw_i2c_prepare(struct device *dev) 304 { 305 return pm_runtime_suspended(dev); 306 } 307 308 static void dw_i2c_complete(struct device *dev) 309 { 310 if (dev->power.direct_complete) 311 pm_request_resume(dev); 312 } 313 #else 314 #define dw_i2c_prepare NULL 315 #define dw_i2c_complete NULL 316 #endif 317 318 #ifdef CONFIG_PM 319 static int dw_i2c_suspend(struct device *dev) 320 { 321 struct platform_device *pdev = to_platform_device(dev); 322 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 323 324 i2c_dw_disable(i_dev); 325 clk_disable_unprepare(i_dev->clk); 326 327 return 0; 328 } 329 330 static int dw_i2c_resume(struct device *dev) 331 { 332 struct platform_device *pdev = to_platform_device(dev); 333 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 334 335 clk_prepare_enable(i_dev->clk); 336 337 if (!i_dev->pm_runtime_disabled) 338 i2c_dw_init(i_dev); 339 340 return 0; 341 } 342 343 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 344 .prepare = dw_i2c_prepare, 345 .complete = dw_i2c_complete, 346 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_suspend, dw_i2c_resume) 347 SET_RUNTIME_PM_OPS(dw_i2c_suspend, dw_i2c_resume, NULL) 348 }; 349 350 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 351 #else 352 #define DW_I2C_DEV_PMOPS NULL 353 #endif 354 355 /* work with hotplug and coldplug */ 356 MODULE_ALIAS("platform:i2c_designware"); 357 358 static struct platform_driver dw_i2c_driver = { 359 .probe = dw_i2c_probe, 360 .remove = dw_i2c_remove, 361 .driver = { 362 .name = "i2c_designware", 363 .of_match_table = of_match_ptr(dw_i2c_of_match), 364 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 365 .pm = DW_I2C_DEV_PMOPS, 366 }, 367 }; 368 369 static int __init dw_i2c_init_driver(void) 370 { 371 return platform_driver_register(&dw_i2c_driver); 372 } 373 subsys_initcall(dw_i2c_init_driver); 374 375 static void __exit dw_i2c_exit_driver(void) 376 { 377 platform_driver_unregister(&dw_i2c_driver); 378 } 379 module_exit(dw_i2c_exit_driver); 380 381 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 382 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 383 MODULE_LICENSE("GPL"); 384