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/errno.h> 34 #include <linux/sched.h> 35 #include <linux/err.h> 36 #include <linux/interrupt.h> 37 #include <linux/of.h> 38 #include <linux/platform_device.h> 39 #include <linux/pm.h> 40 #include <linux/pm_runtime.h> 41 #include <linux/io.h> 42 #include <linux/slab.h> 43 #include <linux/acpi.h> 44 #include "i2c-designware-core.h" 45 46 static struct i2c_algorithm i2c_dw_algo = { 47 .master_xfer = i2c_dw_xfer, 48 .functionality = i2c_dw_func, 49 }; 50 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 51 { 52 return clk_get_rate(dev->clk)/1000; 53 } 54 55 #ifdef CONFIG_ACPI 56 static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], 57 u16 *hcnt, u16 *lcnt, u32 *sda_hold) 58 { 59 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; 60 acpi_handle handle = ACPI_HANDLE(&pdev->dev); 61 union acpi_object *obj; 62 63 if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) 64 return; 65 66 obj = (union acpi_object *)buf.pointer; 67 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { 68 const union acpi_object *objs = obj->package.elements; 69 70 *hcnt = (u16)objs[0].integer.value; 71 *lcnt = (u16)objs[1].integer.value; 72 if (sda_hold) 73 *sda_hold = (u32)objs[2].integer.value; 74 } 75 76 kfree(buf.pointer); 77 } 78 79 static int dw_i2c_acpi_configure(struct platform_device *pdev) 80 { 81 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 82 bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST; 83 84 if (!ACPI_HANDLE(&pdev->dev)) 85 return -ENODEV; 86 87 dev->adapter.nr = -1; 88 dev->tx_fifo_depth = 32; 89 dev->rx_fifo_depth = 32; 90 91 /* 92 * Try to get SDA hold time and *CNT values from an ACPI method if 93 * it exists for both supported speed modes. 94 */ 95 dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, 96 fs_mode ? NULL : &dev->sda_hold_time); 97 dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, 98 fs_mode ? &dev->sda_hold_time : NULL); 99 100 return 0; 101 } 102 103 static const struct acpi_device_id dw_i2c_acpi_match[] = { 104 { "INT33C2", 0 }, 105 { "INT33C3", 0 }, 106 { "INT3432", 0 }, 107 { "INT3433", 0 }, 108 { "80860F41", 0 }, 109 { } 110 }; 111 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 112 #else 113 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 114 { 115 return -ENODEV; 116 } 117 #endif 118 119 static int dw_i2c_probe(struct platform_device *pdev) 120 { 121 struct dw_i2c_dev *dev; 122 struct i2c_adapter *adap; 123 struct resource *mem; 124 int irq, r; 125 126 irq = platform_get_irq(pdev, 0); 127 if (irq < 0) { 128 dev_err(&pdev->dev, "no irq resource?\n"); 129 return irq; /* -ENXIO */ 130 } 131 132 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 133 if (!dev) 134 return -ENOMEM; 135 136 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 137 dev->base = devm_ioremap_resource(&pdev->dev, mem); 138 if (IS_ERR(dev->base)) 139 return PTR_ERR(dev->base); 140 141 init_completion(&dev->cmd_complete); 142 mutex_init(&dev->lock); 143 dev->dev = &pdev->dev; 144 dev->irq = irq; 145 platform_set_drvdata(pdev, dev); 146 147 dev->clk = devm_clk_get(&pdev->dev, NULL); 148 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 149 150 if (IS_ERR(dev->clk)) 151 return PTR_ERR(dev->clk); 152 clk_prepare_enable(dev->clk); 153 154 if (pdev->dev.of_node) { 155 u32 ht = 0; 156 u32 ic_clk = dev->get_clk_rate_khz(dev); 157 158 of_property_read_u32(pdev->dev.of_node, 159 "i2c-sda-hold-time-ns", &ht); 160 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 161 1000000); 162 163 of_property_read_u32(pdev->dev.of_node, 164 "i2c-sda-falling-time-ns", 165 &dev->sda_falling_time); 166 of_property_read_u32(pdev->dev.of_node, 167 "i2c-scl-falling-time-ns", 168 &dev->scl_falling_time); 169 } 170 171 dev->functionality = 172 I2C_FUNC_I2C | 173 I2C_FUNC_10BIT_ADDR | 174 I2C_FUNC_SMBUS_BYTE | 175 I2C_FUNC_SMBUS_BYTE_DATA | 176 I2C_FUNC_SMBUS_WORD_DATA | 177 I2C_FUNC_SMBUS_I2C_BLOCK; 178 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 179 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 180 181 /* Try first if we can configure the device from ACPI */ 182 r = dw_i2c_acpi_configure(pdev); 183 if (r) { 184 u32 param1 = i2c_dw_read_comp_param(dev); 185 186 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 187 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 188 dev->adapter.nr = pdev->id; 189 } 190 r = i2c_dw_init(dev); 191 if (r) 192 return r; 193 194 i2c_dw_disable_int(dev); 195 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 196 pdev->name, dev); 197 if (r) { 198 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 199 return r; 200 } 201 202 adap = &dev->adapter; 203 i2c_set_adapdata(adap, dev); 204 adap->owner = THIS_MODULE; 205 adap->class = I2C_CLASS_HWMON | I2C_CLASS_DEPRECATED; 206 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 207 sizeof(adap->name)); 208 adap->algo = &i2c_dw_algo; 209 adap->dev.parent = &pdev->dev; 210 adap->dev.of_node = pdev->dev.of_node; 211 212 r = i2c_add_numbered_adapter(adap); 213 if (r) { 214 dev_err(&pdev->dev, "failure adding adapter\n"); 215 return r; 216 } 217 218 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 219 pm_runtime_use_autosuspend(&pdev->dev); 220 pm_runtime_set_active(&pdev->dev); 221 pm_runtime_enable(&pdev->dev); 222 223 return 0; 224 } 225 226 static int dw_i2c_remove(struct platform_device *pdev) 227 { 228 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 229 230 pm_runtime_get_sync(&pdev->dev); 231 232 i2c_del_adapter(&dev->adapter); 233 234 i2c_dw_disable(dev); 235 236 pm_runtime_put(&pdev->dev); 237 pm_runtime_disable(&pdev->dev); 238 239 return 0; 240 } 241 242 #ifdef CONFIG_OF 243 static const struct of_device_id dw_i2c_of_match[] = { 244 { .compatible = "snps,designware-i2c", }, 245 {}, 246 }; 247 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 248 #endif 249 250 #ifdef CONFIG_PM 251 static int dw_i2c_suspend(struct device *dev) 252 { 253 struct platform_device *pdev = to_platform_device(dev); 254 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 255 256 i2c_dw_disable(i_dev); 257 clk_disable_unprepare(i_dev->clk); 258 259 return 0; 260 } 261 262 static int dw_i2c_resume(struct device *dev) 263 { 264 struct platform_device *pdev = to_platform_device(dev); 265 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 266 267 clk_prepare_enable(i_dev->clk); 268 i2c_dw_init(i_dev); 269 270 return 0; 271 } 272 #endif 273 274 static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, 275 dw_i2c_resume, NULL); 276 277 /* work with hotplug and coldplug */ 278 MODULE_ALIAS("platform:i2c_designware"); 279 280 static struct platform_driver dw_i2c_driver = { 281 .probe = dw_i2c_probe, 282 .remove = dw_i2c_remove, 283 .driver = { 284 .name = "i2c_designware", 285 .owner = THIS_MODULE, 286 .of_match_table = of_match_ptr(dw_i2c_of_match), 287 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 288 .pm = &dw_i2c_dev_pm_ops, 289 }, 290 }; 291 292 static int __init dw_i2c_init_driver(void) 293 { 294 return platform_driver_register(&dw_i2c_driver); 295 } 296 subsys_initcall(dw_i2c_init_driver); 297 298 static void __exit dw_i2c_exit_driver(void) 299 { 300 platform_driver_unregister(&dw_i2c_driver); 301 } 302 module_exit(dw_i2c_exit_driver); 303 304 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 305 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 306 MODULE_LICENSE("GPL"); 307