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/io.h> 40 #include <linux/slab.h> 41 #include <linux/acpi.h> 42 #include <linux/platform_data/i2c-designware.h> 43 #include "i2c-designware-core.h" 44 45 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 46 { 47 return clk_get_rate(dev->clk)/1000; 48 } 49 50 #ifdef CONFIG_ACPI 51 /* 52 * The HCNT/LCNT information coming from ACPI should be the most accurate 53 * for given platform. However, some systems get it wrong. On such systems 54 * we get better results by calculating those based on the input clock. 55 */ 56 static const struct dmi_system_id dw_i2c_no_acpi_params[] = { 57 { 58 .ident = "Dell Inspiron 7348", 59 .matches = { 60 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 61 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7348"), 62 }, 63 }, 64 { } 65 }; 66 67 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 68 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 69 { 70 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 71 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 72 union acpi_object *obj; 73 74 if (dmi_check_system(dw_i2c_no_acpi_params)) 75 return; 76 77 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 78 return; 79 80 obj = (union acpi_object *)buf.pointer; 81 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 82 const union acpi_object *objs = obj->package.elements; 83 84 *hcnt = (u16)objs[0].integer.value; 85 *lcnt = (u16)objs[1].integer.value; 86 if (sda_hold) 87 *sda_hold = (u32)objs[2].integer.value; 88 } 89 90 kfree(buf.pointer); 91 } 92 93 static int dw_i2c_acpi_configure(struct platform_device *pdev) 94 { 95 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 96 const struct acpi_device_id *id; 97 98 dev->adapter.nr = -1; 99 dev->tx_fifo_depth = 32; 100 dev->rx_fifo_depth = 32; 101 102 /* 103 * Try to get SDA hold time and *CNT values from an ACPI method if 104 * it exists for both supported speed modes. 105 */ 106 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 107 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 108 &dev->sda_hold_time); 109 110 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 111 if (id && id->driver_data) 112 dev->accessor_flags |= (u32)id->driver_data; 113 114 return 0; 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", ACCESS_INTR_MASK }, 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 #endif 134 135 static int dw_i2c_plat_probe(struct platform_device *pdev) 136 { 137 struct dw_i2c_dev *dev; 138 struct i2c_adapter *adap; 139 struct resource *mem; 140 struct dw_i2c_platform_data *pdata; 141 int irq, r; 142 u32 clk_freq, ht = 0; 143 144 irq = platform_get_irq(pdev, 0); 145 if (irq < 0) 146 return irq; 147 148 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 149 if (!dev) 150 return -ENOMEM; 151 152 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 153 dev->base = devm_ioremap_resource(&pdev->dev, mem); 154 if (IS_ERR(dev->base)) 155 return PTR_ERR(dev->base); 156 157 dev->dev = &pdev->dev; 158 dev->irq = irq; 159 platform_set_drvdata(pdev, dev); 160 161 /* fast mode by default because of legacy reasons */ 162 clk_freq = 400000; 163 164 if (has_acpi_companion(&pdev->dev)) { 165 dw_i2c_acpi_configure(pdev); 166 } else if (pdev->dev.of_node) { 167 of_property_read_u32(pdev->dev.of_node, 168 "i2c-sda-hold-time-ns", &ht); 169 170 of_property_read_u32(pdev->dev.of_node, 171 "i2c-sda-falling-time-ns", 172 &dev->sda_falling_time); 173 of_property_read_u32(pdev->dev.of_node, 174 "i2c-scl-falling-time-ns", 175 &dev->scl_falling_time); 176 177 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 178 &clk_freq); 179 180 /* Only standard mode at 100kHz and fast mode at 400kHz 181 * are supported. 182 */ 183 if (clk_freq != 100000 && clk_freq != 400000) { 184 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 185 return -EINVAL; 186 } 187 } else { 188 pdata = dev_get_platdata(&pdev->dev); 189 if (pdata) 190 clk_freq = pdata->i2c_scl_freq; 191 } 192 193 r = i2c_dw_eval_lock_support(dev); 194 if (r) 195 return r; 196 197 dev->functionality = 198 I2C_FUNC_I2C | 199 I2C_FUNC_10BIT_ADDR | 200 I2C_FUNC_SMBUS_BYTE | 201 I2C_FUNC_SMBUS_BYTE_DATA | 202 I2C_FUNC_SMBUS_WORD_DATA | 203 I2C_FUNC_SMBUS_I2C_BLOCK; 204 if (clk_freq == 100000) 205 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 206 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 207 else 208 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 209 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 210 211 dev->clk = devm_clk_get(&pdev->dev, NULL); 212 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 213 if (IS_ERR(dev->clk)) 214 return PTR_ERR(dev->clk); 215 clk_prepare_enable(dev->clk); 216 217 if (!dev->sda_hold_time && ht) { 218 u32 ic_clk = dev->get_clk_rate_khz(dev); 219 220 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 221 1000000); 222 } 223 224 if (!dev->tx_fifo_depth) { 225 u32 param1 = i2c_dw_read_comp_param(dev); 226 227 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 228 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 229 dev->adapter.nr = pdev->id; 230 } 231 232 adap = &dev->adapter; 233 adap->owner = THIS_MODULE; 234 adap->class = I2C_CLASS_DEPRECATED; 235 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 236 adap->dev.of_node = pdev->dev.of_node; 237 238 if (dev->pm_runtime_disabled) { 239 pm_runtime_forbid(&pdev->dev); 240 } else { 241 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 242 pm_runtime_use_autosuspend(&pdev->dev); 243 pm_runtime_set_active(&pdev->dev); 244 pm_runtime_enable(&pdev->dev); 245 } 246 247 r = i2c_dw_probe(dev); 248 if (r && !dev->pm_runtime_disabled) 249 pm_runtime_disable(&pdev->dev); 250 251 return r; 252 } 253 254 static int dw_i2c_plat_remove(struct platform_device *pdev) 255 { 256 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 257 258 pm_runtime_get_sync(&pdev->dev); 259 260 i2c_del_adapter(&dev->adapter); 261 262 i2c_dw_disable(dev); 263 264 pm_runtime_dont_use_autosuspend(&pdev->dev); 265 pm_runtime_put_sync(&pdev->dev); 266 if (!dev->pm_runtime_disabled) 267 pm_runtime_disable(&pdev->dev); 268 269 return 0; 270 } 271 272 #ifdef CONFIG_OF 273 static const struct of_device_id dw_i2c_of_match[] = { 274 { .compatible = "snps,designware-i2c", }, 275 {}, 276 }; 277 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 278 #endif 279 280 #ifdef CONFIG_PM_SLEEP 281 static int dw_i2c_plat_prepare(struct device *dev) 282 { 283 return pm_runtime_suspended(dev); 284 } 285 286 static void dw_i2c_plat_complete(struct device *dev) 287 { 288 if (dev->power.direct_complete) 289 pm_request_resume(dev); 290 } 291 #else 292 #define dw_i2c_plat_prepare NULL 293 #define dw_i2c_plat_complete NULL 294 #endif 295 296 #ifdef CONFIG_PM 297 static int dw_i2c_plat_suspend(struct device *dev) 298 { 299 struct platform_device *pdev = to_platform_device(dev); 300 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 301 302 i2c_dw_disable(i_dev); 303 clk_disable_unprepare(i_dev->clk); 304 305 return 0; 306 } 307 308 static int dw_i2c_plat_resume(struct device *dev) 309 { 310 struct platform_device *pdev = to_platform_device(dev); 311 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 312 313 clk_prepare_enable(i_dev->clk); 314 315 if (!i_dev->pm_runtime_disabled) 316 i2c_dw_init(i_dev); 317 318 return 0; 319 } 320 321 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 322 .prepare = dw_i2c_plat_prepare, 323 .complete = dw_i2c_plat_complete, 324 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 325 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 326 }; 327 328 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 329 #else 330 #define DW_I2C_DEV_PMOPS NULL 331 #endif 332 333 /* work with hotplug and coldplug */ 334 MODULE_ALIAS("platform:i2c_designware"); 335 336 static struct platform_driver dw_i2c_driver = { 337 .probe = dw_i2c_plat_probe, 338 .remove = dw_i2c_plat_remove, 339 .driver = { 340 .name = "i2c_designware", 341 .of_match_table = of_match_ptr(dw_i2c_of_match), 342 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 343 .pm = DW_I2C_DEV_PMOPS, 344 }, 345 }; 346 347 static int __init dw_i2c_init_driver(void) 348 { 349 return platform_driver_register(&dw_i2c_driver); 350 } 351 subsys_initcall(dw_i2c_init_driver); 352 353 static void __exit dw_i2c_exit_driver(void) 354 { 355 platform_driver_unregister(&dw_i2c_driver); 356 } 357 module_exit(dw_i2c_exit_driver); 358 359 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 360 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 361 MODULE_LICENSE("GPL"); 362