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 dev_err(&pdev->dev, "no irq resource?\n"); 148 return irq; /* -ENXIO */ 149 } 150 151 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 152 if (!dev) 153 return -ENOMEM; 154 155 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 156 dev->base = devm_ioremap_resource(&pdev->dev, mem); 157 if (IS_ERR(dev->base)) 158 return PTR_ERR(dev->base); 159 160 init_completion(&dev->cmd_complete); 161 mutex_init(&dev->lock); 162 dev->dev = &pdev->dev; 163 dev->irq = irq; 164 platform_set_drvdata(pdev, dev); 165 166 /* fast mode by default because of legacy reasons */ 167 clk_freq = 400000; 168 169 if (ACPI_COMPANION(&pdev->dev)) { 170 dw_i2c_acpi_configure(pdev); 171 } else if (pdev->dev.of_node) { 172 of_property_read_u32(pdev->dev.of_node, 173 "i2c-sda-hold-time-ns", &ht); 174 175 of_property_read_u32(pdev->dev.of_node, 176 "i2c-sda-falling-time-ns", 177 &dev->sda_falling_time); 178 of_property_read_u32(pdev->dev.of_node, 179 "i2c-scl-falling-time-ns", 180 &dev->scl_falling_time); 181 182 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 183 &clk_freq); 184 185 /* Only standard mode at 100kHz and fast mode at 400kHz 186 * are supported. 187 */ 188 if (clk_freq != 100000 && clk_freq != 400000) { 189 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 190 return -EINVAL; 191 } 192 } else { 193 pdata = dev_get_platdata(&pdev->dev); 194 if (pdata) 195 clk_freq = pdata->i2c_scl_freq; 196 } 197 198 r = i2c_dw_eval_lock_support(dev); 199 if (r) 200 return r; 201 202 dev->functionality = 203 I2C_FUNC_I2C | 204 I2C_FUNC_10BIT_ADDR | 205 I2C_FUNC_SMBUS_BYTE | 206 I2C_FUNC_SMBUS_BYTE_DATA | 207 I2C_FUNC_SMBUS_WORD_DATA | 208 I2C_FUNC_SMBUS_I2C_BLOCK; 209 if (clk_freq == 100000) 210 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 211 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_STD; 212 else 213 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 214 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 215 216 dev->clk = devm_clk_get(&pdev->dev, NULL); 217 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 218 if (IS_ERR(dev->clk)) 219 return PTR_ERR(dev->clk); 220 clk_prepare_enable(dev->clk); 221 222 if (!dev->sda_hold_time && ht) { 223 u32 ic_clk = dev->get_clk_rate_khz(dev); 224 225 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 226 1000000); 227 } 228 229 if (!dev->tx_fifo_depth) { 230 u32 param1 = i2c_dw_read_comp_param(dev); 231 232 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 233 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 234 dev->adapter.nr = pdev->id; 235 } 236 r = i2c_dw_init(dev); 237 if (r) 238 return r; 239 240 i2c_dw_disable_int(dev); 241 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 242 pdev->name, dev); 243 if (r) { 244 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 245 return r; 246 } 247 248 adap = &dev->adapter; 249 i2c_set_adapdata(adap, dev); 250 adap->owner = THIS_MODULE; 251 adap->class = I2C_CLASS_DEPRECATED; 252 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 253 sizeof(adap->name)); 254 adap->algo = &i2c_dw_algo; 255 adap->dev.parent = &pdev->dev; 256 adap->dev.of_node = pdev->dev.of_node; 257 258 r = i2c_add_numbered_adapter(adap); 259 if (r) { 260 dev_err(&pdev->dev, "failure adding adapter\n"); 261 return r; 262 } 263 264 if (dev->pm_runtime_disabled) { 265 pm_runtime_forbid(&pdev->dev); 266 } else { 267 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 268 pm_runtime_use_autosuspend(&pdev->dev); 269 pm_runtime_set_active(&pdev->dev); 270 pm_runtime_enable(&pdev->dev); 271 } 272 273 return 0; 274 } 275 276 static int dw_i2c_remove(struct platform_device *pdev) 277 { 278 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 279 280 pm_runtime_get_sync(&pdev->dev); 281 282 i2c_del_adapter(&dev->adapter); 283 284 i2c_dw_disable(dev); 285 286 pm_runtime_put(&pdev->dev); 287 pm_runtime_disable(&pdev->dev); 288 289 if (ACPI_COMPANION(&pdev->dev)) 290 dw_i2c_acpi_unconfigure(pdev); 291 292 return 0; 293 } 294 295 #ifdef CONFIG_OF 296 static const struct of_device_id dw_i2c_of_match[] = { 297 { .compatible = "snps,designware-i2c", }, 298 {}, 299 }; 300 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 301 #endif 302 303 #ifdef CONFIG_PM 304 static int dw_i2c_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 clk_disable_unprepare(i_dev->clk); 311 312 return 0; 313 } 314 315 static int dw_i2c_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 clk_prepare_enable(i_dev->clk); 321 322 if (!i_dev->pm_runtime_disabled) 323 i2c_dw_init(i_dev); 324 325 return 0; 326 } 327 #endif 328 329 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, 330 dw_i2c_resume, NULL); 331 332 /* work with hotplug and coldplug */ 333 MODULE_ALIAS("platform:i2c_designware"); 334 335 static struct platform_driver dw_i2c_driver = { 336 .probe = dw_i2c_probe, 337 .remove = dw_i2c_remove, 338 .driver = { 339 .name = "i2c_designware", 340 .of_match_table = of_match_ptr(dw_i2c_of_match), 341 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 342 .pm = &dw_i2c_dev_pm_ops, 343 }, 344 }; 345 346 static int __init dw_i2c_init_driver(void) 347 { 348 return platform_driver_register(&dw_i2c_driver); 349 } 350 subsys_initcall(dw_i2c_init_driver); 351 352 static void __exit dw_i2c_exit_driver(void) 353 { 354 platform_driver_unregister(&dw_i2c_driver); 355 } 356 module_exit(dw_i2c_exit_driver); 357 358 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 359 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 360 MODULE_LICENSE("GPL"); 361