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/of_i2c.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 "i2c-designware-core.h" 46 47 static struct i2c_algorithm i2c_dw_algo = { 48 .master_xfer = i2c_dw_xfer, 49 .functionality = i2c_dw_func, 50 }; 51 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 52 { 53 return clk_get_rate(dev->clk)/1000; 54 } 55 56 #ifdef CONFIG_ACPI 57 static int dw_i2c_acpi_configure(struct platform_device *pdev) 58 { 59 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 60 61 if (!ACPI_HANDLE(&pdev->dev)) 62 return -ENODEV; 63 64 dev->adapter.nr = -1; 65 dev->tx_fifo_depth = 32; 66 dev->rx_fifo_depth = 32; 67 return 0; 68 } 69 70 static const struct acpi_device_id dw_i2c_acpi_match[] = { 71 { "INT33C2", 0 }, 72 { "INT33C3", 0 }, 73 { "80860F41", 0 }, 74 { } 75 }; 76 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); 77 #else 78 static inline int dw_i2c_acpi_configure(struct platform_device *pdev) 79 { 80 return -ENODEV; 81 } 82 #endif 83 84 static int dw_i2c_probe(struct platform_device *pdev) 85 { 86 struct dw_i2c_dev *dev; 87 struct i2c_adapter *adap; 88 struct resource *mem; 89 int irq, r; 90 91 irq = platform_get_irq(pdev, 0); 92 if (irq < 0) { 93 dev_err(&pdev->dev, "no irq resource?\n"); 94 return irq; /* -ENXIO */ 95 } 96 97 dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); 98 if (!dev) 99 return -ENOMEM; 100 101 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 102 dev->base = devm_ioremap_resource(&pdev->dev, mem); 103 if (IS_ERR(dev->base)) 104 return PTR_ERR(dev->base); 105 106 init_completion(&dev->cmd_complete); 107 mutex_init(&dev->lock); 108 dev->dev = &pdev->dev; 109 dev->irq = irq; 110 platform_set_drvdata(pdev, dev); 111 112 dev->clk = devm_clk_get(&pdev->dev, NULL); 113 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 114 115 if (IS_ERR(dev->clk)) 116 return PTR_ERR(dev->clk); 117 clk_prepare_enable(dev->clk); 118 119 if (pdev->dev.of_node) { 120 u32 ht = 0; 121 u32 ic_clk = dev->get_clk_rate_khz(dev); 122 123 of_property_read_u32(pdev->dev.of_node, 124 "i2c-sda-hold-time-ns", &ht); 125 dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, 126 1000000); 127 } 128 129 dev->functionality = 130 I2C_FUNC_I2C | 131 I2C_FUNC_10BIT_ADDR | 132 I2C_FUNC_SMBUS_BYTE | 133 I2C_FUNC_SMBUS_BYTE_DATA | 134 I2C_FUNC_SMBUS_WORD_DATA | 135 I2C_FUNC_SMBUS_I2C_BLOCK; 136 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 137 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 138 139 /* Try first if we can configure the device from ACPI */ 140 r = dw_i2c_acpi_configure(pdev); 141 if (r) { 142 u32 param1 = i2c_dw_read_comp_param(dev); 143 144 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 145 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 146 dev->adapter.nr = pdev->id; 147 } 148 r = i2c_dw_init(dev); 149 if (r) 150 return r; 151 152 i2c_dw_disable_int(dev); 153 r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, 154 pdev->name, dev); 155 if (r) { 156 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 157 return r; 158 } 159 160 adap = &dev->adapter; 161 i2c_set_adapdata(adap, dev); 162 adap->owner = THIS_MODULE; 163 adap->class = I2C_CLASS_HWMON; 164 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 165 sizeof(adap->name)); 166 adap->algo = &i2c_dw_algo; 167 adap->dev.parent = &pdev->dev; 168 adap->dev.of_node = pdev->dev.of_node; 169 170 r = i2c_add_numbered_adapter(adap); 171 if (r) { 172 dev_err(&pdev->dev, "failure adding adapter\n"); 173 return r; 174 } 175 of_i2c_register_devices(adap); 176 acpi_i2c_register_devices(adap); 177 178 pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); 179 pm_runtime_use_autosuspend(&pdev->dev); 180 pm_runtime_set_active(&pdev->dev); 181 pm_runtime_enable(&pdev->dev); 182 183 return 0; 184 } 185 186 static int dw_i2c_remove(struct platform_device *pdev) 187 { 188 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 189 190 pm_runtime_get_sync(&pdev->dev); 191 192 i2c_del_adapter(&dev->adapter); 193 194 i2c_dw_disable(dev); 195 196 pm_runtime_put(&pdev->dev); 197 pm_runtime_disable(&pdev->dev); 198 199 return 0; 200 } 201 202 #ifdef CONFIG_OF 203 static const struct of_device_id dw_i2c_of_match[] = { 204 { .compatible = "snps,designware-i2c", }, 205 {}, 206 }; 207 MODULE_DEVICE_TABLE(of, dw_i2c_of_match); 208 #endif 209 210 #ifdef CONFIG_PM 211 static int dw_i2c_suspend(struct device *dev) 212 { 213 struct platform_device *pdev = to_platform_device(dev); 214 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 215 216 clk_disable_unprepare(i_dev->clk); 217 218 return 0; 219 } 220 221 static int dw_i2c_resume(struct device *dev) 222 { 223 struct platform_device *pdev = to_platform_device(dev); 224 struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); 225 226 clk_prepare_enable(i_dev->clk); 227 i2c_dw_init(i_dev); 228 229 return 0; 230 } 231 #endif 232 233 static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume); 234 235 /* work with hotplug and coldplug */ 236 MODULE_ALIAS("platform:i2c_designware"); 237 238 static struct platform_driver dw_i2c_driver = { 239 .remove = dw_i2c_remove, 240 .driver = { 241 .name = "i2c_designware", 242 .owner = THIS_MODULE, 243 .of_match_table = of_match_ptr(dw_i2c_of_match), 244 .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), 245 .pm = &dw_i2c_dev_pm_ops, 246 }, 247 }; 248 249 static int __init dw_i2c_init_driver(void) 250 { 251 return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe); 252 } 253 subsys_initcall(dw_i2c_init_driver); 254 255 static void __exit dw_i2c_exit_driver(void) 256 { 257 platform_driver_unregister(&dw_i2c_driver); 258 } 259 module_exit(dw_i2c_exit_driver); 260 261 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 262 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 263 MODULE_LICENSE("GPL"); 264