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 97 dev->adapter.nr = -1; 98 dev->tx_fifo_depth = 32; 99 dev->rx_fifo_depth = 32; 100 101 /* 102 * Try to get SDA hold time and *CNT values from an ACPI method if 103 * it exists for both supported speed modes. 104 */ 105 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 106 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 107 &dev->sda_hold_time); 108 109 return 0; 110 } 111 112 static const struct acpi_device_id dw_i2c_acpi_match[] = { 113 { "INT33C2", 0 }, 114 { "INT33C3", 0 }, 115 { "INT3432", 0 }, 116 { "INT3433", 0 }, 117 { "80860F41", 0 }, 118 { "808622C1", 0 }, 119 { "AMD0010", 0 }, 120 { } 121 }; 122 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 123 #else 124 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 125 { 126 return -ENODEV; 127 } 128 #endif 129 130 static int dw_i2c_plat_probe(struct platform_device *pdev) 131 { 132 struct dw_i2c_dev *dev; 133 struct i2c_adapter *adap; 134 struct resource *mem; 135 struct dw_i2c_platform_data *pdata; 136 int irq, r; 137 u32 clk_freq, ht = 0; 138 139 irq = platform_get_irq(pdev, 0); 140 if (irq < 0) 141 return irq; 142 143 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 144 if (!dev) 145 return -ENOMEM; 146 147 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 148 dev->base = devm_ioremap_resource(&pdev->dev, mem); 149 if (IS_ERR(dev->base)) 150 return PTR_ERR(dev->base); 151 152 dev->dev = &pdev->dev; 153 dev->irq = irq; 154 platform_set_drvdata(pdev, dev); 155 156 /* fast mode by default because of legacy reasons */ 157 clk_freq = 400000; 158 159 if (has_acpi_companion(&pdev->dev)) { 160 dw_i2c_acpi_configure(pdev); 161 } else if (pdev->dev.of_node) { 162 of_property_read_u32(pdev->dev.of_node, 163 "i2c-sda-hold-time-ns", &ht); 164 165 of_property_read_u32(pdev->dev.of_node, 166 "i2c-sda-falling-time-ns", 167 &dev->sda_falling_time); 168 of_property_read_u32(pdev->dev.of_node, 169 "i2c-scl-falling-time-ns", 170 &dev->scl_falling_time); 171 172 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 173 &clk_freq); 174 175 /* Only standard mode at 100kHz and fast mode at 400kHz 176 * are supported. 177 */ 178 if (clk_freq != 100000 && clk_freq != 400000) { 179 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 180 return -EINVAL; 181 } 182 } else { 183 pdata = dev_get_platdata(&pdev->dev); 184 if (pdata) 185 clk_freq = pdata->i2c_scl_freq; 186 } 187 188 r = i2c_dw_eval_lock_support(dev); 189 if (r) 190 return r; 191 192 dev->functionality = 193 I2C_FUNC_I2C | 194 I2C_FUNC_10BIT_ADDR | 195 I2C_FUNC_SMBUS_BYTE | 196 I2C_FUNC_SMBUS_BYTE_DATA | 197 I2C_FUNC_SMBUS_WORD_DATA | 198 I2C_FUNC_SMBUS_I2C_BLOCK; 199 if (clk_freq == 100000) 200 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 201 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 202 else 203 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 204 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 205 206 dev->clk = devm_clk_get(&pdev->dev, NULL); 207 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 208 if (IS_ERR(dev->clk)) 209 return PTR_ERR(dev->clk); 210 clk_prepare_enable(dev->clk); 211 212 if (!dev->sda_hold_time && ht) { 213 u32 ic_clk = dev->get_clk_rate_khz(dev); 214 215 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 216 1000000); 217 } 218 219 if (!dev->tx_fifo_depth) { 220 u32 param1 = i2c_dw_read_comp_param(dev); 221 222 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 223 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 224 dev->adapter.nr = pdev->id; 225 } 226 227 adap = &dev->adapter; 228 adap->owner = THIS_MODULE; 229 adap->class = I2C_CLASS_DEPRECATED; 230 ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev)); 231 adap->dev.of_node = pdev->dev.of_node; 232 233 if (dev->pm_runtime_disabled) { 234 pm_runtime_forbid(&pdev->dev); 235 } else { 236 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 237 pm_runtime_use_autosuspend(&pdev->dev); 238 pm_runtime_set_active(&pdev->dev); 239 pm_runtime_enable(&pdev->dev); 240 } 241 242 r = i2c_dw_probe(dev); 243 if (r) { 244 pm_runtime_disable(&pdev->dev); 245 return r; 246 } 247 248 return 0; 249 } 250 251 static int dw_i2c_plat_remove(struct platform_device *pdev) 252 { 253 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 254 255 pm_runtime_get_sync(&pdev->dev); 256 257 i2c_del_adapter(&dev->adapter); 258 259 i2c_dw_disable(dev); 260 261 pm_runtime_dont_use_autosuspend(&pdev->dev); 262 pm_runtime_put_sync(&pdev->dev); 263 pm_runtime_disable(&pdev->dev); 264 265 return 0; 266 } 267 268 #ifdef CONFIG_OF 269 static const struct of_device_id dw_i2c_of_match[] = { 270 { .compatible = "snps,designware-i2c", }, 271 {}, 272 }; 273 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 274 #endif 275 276 #ifdef CONFIG_PM_SLEEP 277 static int dw_i2c_plat_prepare(struct device *dev) 278 { 279 return pm_runtime_suspended(dev); 280 } 281 282 static void dw_i2c_plat_complete(struct device *dev) 283 { 284 if (dev->power.direct_complete) 285 pm_request_resume(dev); 286 } 287 #else 288 #define dw_i2c_plat_prepare NULL 289 #define dw_i2c_plat_complete NULL 290 #endif 291 292 #ifdef CONFIG_PM 293 static int dw_i2c_plat_suspend(struct device *dev) 294 { 295 struct platform_device *pdev = to_platform_device(dev); 296 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 297 298 i2c_dw_disable(i_dev); 299 clk_disable_unprepare(i_dev->clk); 300 301 return 0; 302 } 303 304 static int dw_i2c_plat_resume(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 clk_prepare_enable(i_dev->clk); 310 311 if (!i_dev->pm_runtime_disabled) 312 i2c_dw_init(i_dev); 313 314 return 0; 315 } 316 317 static const struct dev_pm_ops dw_i2c_dev_pm_ops = { 318 .prepare = dw_i2c_plat_prepare, 319 .complete = dw_i2c_plat_complete, 320 SET_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume) 321 SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL) 322 }; 323 324 #define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops) 325 #else 326 #define DW_I2C_DEV_PMOPS NULL 327 #endif 328 329 /* work with hotplug and coldplug */ 330 MODULE_ALIAS("platform:i2c_designware"); 331 332 static struct platform_driver dw_i2c_driver = { 333 .probe = dw_i2c_plat_probe, 334 .remove = dw_i2c_plat_remove, 335 .driver = { 336 .name = "i2c_designware", 337 .of_match_table = of_match_ptr(dw_i2c_of_match), 338 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 339 .pm = DW_I2C_DEV_PMOPS, 340 }, 341 }; 342 343 static int __init dw_i2c_init_driver(void) 344 { 345 return platform_driver_register(&dw_i2c_driver); 346 } 347 subsys_initcall(dw_i2c_init_driver); 348 349 static void __exit dw_i2c_exit_driver(void) 350 { 351 platform_driver_unregister(&dw_i2c_driver); 352 } 353 module_exit(dw_i2c_exit_driver); 354 355 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 356 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 357 MODULE_LICENSE("GPL"); 358