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 { "80860F41", 0 }, 107 { } 108 }; 109 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 110 #else 111 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 112 { 113 return -ENODEV; 114 } 115 #endif 116 117 static int dw_i2c_probe(struct platform_device *pdev) 118 { 119 struct dw_i2c_dev *dev; 120 struct i2c_adapter *adap; 121 struct resource *mem; 122 int irq, r; 123 124 irq = platform_get_irq(pdev, 0); 125 if (irq < 0) { 126 dev_err(&pdev->dev, "no irq resource?\n"); 127 return irq; /* -ENXIO */ 128 } 129 130 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 131 if (!dev) 132 return -ENOMEM; 133 134 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 135 dev->base = devm_ioremap_resource(&pdev->dev, mem); 136 if (IS_ERR(dev->base)) 137 return PTR_ERR(dev->base); 138 139 init_completion(&dev->cmd_complete); 140 mutex_init(&dev->lock); 141 dev->dev = &pdev->dev; 142 dev->irq = irq; 143 platform_set_drvdata(pdev, dev); 144 145 dev->clk = devm_clk_get(&pdev->dev, NULL); 146 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 147 148 if (IS_ERR(dev->clk)) 149 return PTR_ERR(dev->clk); 150 clk_prepare_enable(dev->clk); 151 152 if (pdev->dev.of_node) { 153 u32 ht = 0; 154 u32 ic_clk = dev->get_clk_rate_khz(dev); 155 156 of_property_read_u32(pdev->dev.of_node, 157 "i2c-sda-hold-time-ns", &ht); 158 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 159 1000000); 160 } 161 162 dev->functionality = 163 I2C_FUNC_I2C | 164 I2C_FUNC_10BIT_ADDR | 165 I2C_FUNC_SMBUS_BYTE | 166 I2C_FUNC_SMBUS_BYTE_DATA | 167 I2C_FUNC_SMBUS_WORD_DATA | 168 I2C_FUNC_SMBUS_I2C_BLOCK; 169 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 170 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 171 172 /* Try first if we can configure the device from ACPI */ 173 r = dw_i2c_acpi_configure(pdev); 174 if (r) { 175 u32 param1 = i2c_dw_read_comp_param(dev); 176 177 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 178 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 179 dev->adapter.nr = pdev->id; 180 } 181 r = i2c_dw_init(dev); 182 if (r) 183 return r; 184 185 i2c_dw_disable_int(dev); 186 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 187 pdev->name, dev); 188 if (r) { 189 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 190 return r; 191 } 192 193 adap = &dev->adapter; 194 i2c_set_adapdata(adap, dev); 195 adap->owner = THIS_MODULE; 196 adap->class = I2C_CLASS_HWMON; 197 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 198 sizeof(adap->name)); 199 adap->algo = &i2c_dw_algo; 200 adap->dev.parent = &pdev->dev; 201 adap->dev.of_node = pdev->dev.of_node; 202 203 r = i2c_add_numbered_adapter(adap); 204 if (r) { 205 dev_err(&pdev->dev, "failure adding adapter\n"); 206 return r; 207 } 208 209 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 210 pm_runtime_use_autosuspend(&pdev->dev); 211 pm_runtime_set_active(&pdev->dev); 212 pm_runtime_enable(&pdev->dev); 213 214 return 0; 215 } 216 217 static int dw_i2c_remove(struct platform_device *pdev) 218 { 219 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 220 221 pm_runtime_get_sync(&pdev->dev); 222 223 i2c_del_adapter(&dev->adapter); 224 225 i2c_dw_disable(dev); 226 227 pm_runtime_put(&pdev->dev); 228 pm_runtime_disable(&pdev->dev); 229 230 return 0; 231 } 232 233 #ifdef CONFIG_OF 234 static const struct of_device_id dw_i2c_of_match[] = { 235 { .compatible = "snps,designware-i2c", }, 236 {}, 237 }; 238 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 239 #endif 240 241 #ifdef CONFIG_PM_SLEEP 242 static int dw_i2c_suspend(struct device *dev) 243 { 244 struct platform_device *pdev = to_platform_device(dev); 245 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 246 247 clk_disable_unprepare(i_dev->clk); 248 249 return 0; 250 } 251 252 static int dw_i2c_resume(struct device *dev) 253 { 254 struct platform_device *pdev = to_platform_device(dev); 255 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 256 257 clk_prepare_enable(i_dev->clk); 258 i2c_dw_init(i_dev); 259 260 return 0; 261 } 262 263 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume); 264 #define DW_I2C_DEV_PM_OPS (&dw_i2c_dev_pm_ops) 265 #else 266 #define DW_I2C_DEV_PM_OPS NULL 267 #endif 268 269 /* work with hotplug and coldplug */ 270 MODULE_ALIAS("platform:i2c_designware"); 271 272 static struct platform_driver dw_i2c_driver = { 273 .probe = dw_i2c_probe, 274 .remove = dw_i2c_remove, 275 .driver = { 276 .name = "i2c_designware", 277 .owner = THIS_MODULE, 278 .of_match_table = of_match_ptr(dw_i2c_of_match), 279 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 280 .pm = DW_I2C_DEV_PM_OPS, 281 }, 282 }; 283 284 static int __init dw_i2c_init_driver(void) 285 { 286 return platform_driver_register(&dw_i2c_driver); 287 } 288 subsys_initcall(dw_i2c_init_driver); 289 290 static void __exit dw_i2c_exit_driver(void) 291 { 292 platform_driver_unregister(&dw_i2c_driver); 293 } 294 module_exit(dw_i2c_exit_driver); 295 296 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 297 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 298 MODULE_LICENSE("GPL"); 299