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 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 25 * ---------------------------------------------------------------------------- 26 * 27 */ 28 #include <linux/kernel.h> 29 #include <linux/module.h> 30 #include <linux/delay.h> 31 #include <linux/i2c.h> 32 #include <linux/clk.h> 33 #include <linux/clk-provider.h> 34 #include <linux/errno.h> 35 #include <linux/sched.h> 36 #include <linux/err.h> 37 #include <linux/interrupt.h> 38 #include <linux/of.h> 39 #include <linux/platform_device.h> 40 #include <linux/pm.h> 41 #include <linux/pm_runtime.h> 42 #include <linux/io.h> 43 #include <linux/slab.h> 44 #include <linux/acpi.h> 45 #include <linux/platform_data/i2c-designware.h> 46 #include "i2c-designware-core.h" 47 48 static struct i2c_algorithm i2c_dw_algo = { 49 .master_xfer = i2c_dw_xfer, 50 .functionality = i2c_dw_func, 51 }; 52 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 53 { 54 return clk_get_rate(dev->clk)/1000; 55 } 56 57 #ifdef CONFIG_ACPI 58 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 59 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 60 { 61 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 62 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 63 union acpi_object *obj; 64 65 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 66 return; 67 68 obj = (union acpi_object *)buf.pointer; 69 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 70 const union acpi_object *objs = obj->package.elements; 71 72 *hcnt = (u16)objs[0].integer.value; 73 *lcnt = (u16)objs[1].integer.value; 74 if (sda_hold) 75 *sda_hold = (u32)objs[2].integer.value; 76 } 77 78 kfree(buf.pointer); 79 } 80 81 static int dw_i2c_acpi_configure(struct platform_device *pdev) 82 { 83 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 84 const struct acpi_device_id *id; 85 86 dev->adapter.nr = -1; 87 dev->tx_fifo_depth = 32; 88 dev->rx_fifo_depth = 32; 89 90 /* 91 * Try to get SDA hold time and *CNT values from an ACPI method if 92 * it exists for both supported speed modes. 93 */ 94 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, NULL); 95 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 96 &dev->sda_hold_time); 97 98 /* 99 * Provide a way for Designware I2C host controllers that are not 100 * based on Intel LPSS to specify their input clock frequency via 101 * id->driver_data. 102 */ 103 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 104 if (id && id->driver_data) 105 clk_register_fixed_rate(&pdev->dev, dev_name(&pdev->dev), NULL, 106 CLK_IS_ROOT, id->driver_data); 107 108 return 0; 109 } 110 111 static void dw_i2c_acpi_unconfigure(struct platform_device *pdev) 112 { 113 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 114 const struct acpi_device_id *id; 115 116 id = acpi_match_device(pdev->dev.driver->acpi_match_table, &pdev->dev); 117 if (id && id->driver_data) 118 clk_unregister(dev->clk); 119 } 120 121 static const struct acpi_device_id dw_i2c_acpi_match[] = { 122 { "INT33C2", 0 }, 123 { "INT33C3", 0 }, 124 { "INT3432", 0 }, 125 { "INT3433", 0 }, 126 { "80860F41", 0 }, 127 { "808622C1", 0 }, 128 { "AMD0010", 133 * 1000 * 1000 }, 129 { } 130 }; 131 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 132 #else 133 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 134 { 135 return -ENODEV; 136 } 137 static inline void dw_i2c_acpi_unconfigure(struct platform_device *pdev) { } 138 #endif 139 140 static int dw_i2c_probe(struct platform_device *pdev) 141 { 142 struct dw_i2c_dev *dev; 143 struct i2c_adapter *adap; 144 struct resource *mem; 145 struct dw_i2c_platform_data *pdata; 146 int irq, r; 147 u32 clk_freq, ht = 0; 148 149 irq = platform_get_irq(pdev, 0); 150 if (irq < 0) { 151 dev_err(&pdev->dev, "no irq resource?\n"); 152 return irq; /* -ENXIO */ 153 } 154 155 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 156 if (!dev) 157 return -ENOMEM; 158 159 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 160 dev->base = devm_ioremap_resource(&pdev->dev, mem); 161 if (IS_ERR(dev->base)) 162 return PTR_ERR(dev->base); 163 164 init_completion(&dev->cmd_complete); 165 mutex_init(&dev->lock); 166 dev->dev = &pdev->dev; 167 dev->irq = irq; 168 platform_set_drvdata(pdev, dev); 169 170 /* fast mode by default because of legacy reasons */ 171 clk_freq = 400000; 172 173 if (ACPI_COMPANION(&pdev->dev)) { 174 dw_i2c_acpi_configure(pdev); 175 } else if (pdev->dev.of_node) { 176 of_property_read_u32(pdev->dev.of_node, 177 "i2c-sda-hold-time-ns", &ht); 178 179 of_property_read_u32(pdev->dev.of_node, 180 "i2c-sda-falling-time-ns", 181 &dev->sda_falling_time); 182 of_property_read_u32(pdev->dev.of_node, 183 "i2c-scl-falling-time-ns", 184 &dev->scl_falling_time); 185 186 of_property_read_u32(pdev->dev.of_node, "clock-frequency", 187 &clk_freq); 188 189 /* Only standard mode at 100kHz and fast mode at 400kHz 190 * are supported. 191 */ 192 if (clk_freq != 100000 && clk_freq != 400000) { 193 dev_err(&pdev->dev, "Only 100kHz and 400kHz supported"); 194 return -EINVAL; 195 } 196 } else { 197 pdata = dev_get_platdata(&pdev->dev); 198 if (pdata) 199 clk_freq = pdata->i2c_scl_freq; 200 } 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 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 265 pm_runtime_use_autosuspend(&pdev->dev); 266 pm_runtime_set_active(&pdev->dev); 267 pm_runtime_enable(&pdev->dev); 268 269 return 0; 270 } 271 272 static int dw_i2c_remove(struct platform_device *pdev) 273 { 274 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 275 276 pm_runtime_get_sync(&pdev->dev); 277 278 i2c_del_adapter(&dev->adapter); 279 280 i2c_dw_disable(dev); 281 282 pm_runtime_put(&pdev->dev); 283 pm_runtime_disable(&pdev->dev); 284 285 if (ACPI_COMPANION(&pdev->dev)) 286 dw_i2c_acpi_unconfigure(pdev); 287 288 return 0; 289 } 290 291 #ifdef CONFIG_OF 292 static const struct of_device_id dw_i2c_of_match[] = { 293 { .compatible = "snps,designware-i2c", }, 294 {}, 295 }; 296 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 297 #endif 298 299 #ifdef CONFIG_PM 300 static int dw_i2c_suspend(struct device *dev) 301 { 302 struct platform_device *pdev = to_platform_device(dev); 303 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 304 305 i2c_dw_disable(i_dev); 306 clk_disable_unprepare(i_dev->clk); 307 308 return 0; 309 } 310 311 static int dw_i2c_resume(struct device *dev) 312 { 313 struct platform_device *pdev = to_platform_device(dev); 314 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 315 316 clk_prepare_enable(i_dev->clk); 317 i2c_dw_init(i_dev); 318 319 return 0; 320 } 321 #endif 322 323 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, 324 dw_i2c_resume, NULL); 325 326 /* work with hotplug and coldplug */ 327 MODULE_ALIAS("platform:i2c_designware"); 328 329 static struct platform_driver dw_i2c_driver = { 330 .probe = dw_i2c_probe, 331 .remove = dw_i2c_remove, 332 .driver = { 333 .name = "i2c_designware", 334 .owner = THIS_MODULE, 335 .of_match_table = of_match_ptr(dw_i2c_of_match), 336 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 337 .pm = &dw_i2c_dev_pm_ops, 338 }, 339 }; 340 341 static int __init dw_i2c_init_driver(void) 342 { 343 return platform_driver_register(&dw_i2c_driver); 344 } 345 subsys_initcall(dw_i2c_init_driver); 346 347 static void __exit dw_i2c_exit_driver(void) 348 { 349 platform_driver_unregister(&dw_i2c_driver); 350 } 351 module_exit(dw_i2c_exit_driver); 352 353 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 354 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 355 MODULE_LICENSE("GPL"); 356