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/platform_device.h> 38 #include <linux/io.h> 39 #include <linux/slab.h> 40 #include "i2c-designware-core.h" 41 42 static struct i2c_algorithm i2c_dw_algo = { 43 .master_xfer = i2c_dw_xfer, 44 .functionality = i2c_dw_func, 45 }; 46 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) 47 { 48 return clk_get_rate(dev->clk)/1000; 49 } 50 51 static int __devinit dw_i2c_probe(struct platform_device *pdev) 52 { 53 struct dw_i2c_dev *dev; 54 struct i2c_adapter *adap; 55 struct resource *mem, *ioarea; 56 int irq, r; 57 58 /* NOTE: driver uses the static register mapping */ 59 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 60 if (!mem) { 61 dev_err(&pdev->dev, "no mem resource?\n"); 62 return -EINVAL; 63 } 64 65 irq = platform_get_irq(pdev, 0); 66 if (irq < 0) { 67 dev_err(&pdev->dev, "no irq resource?\n"); 68 return irq; /* -ENXIO */ 69 } 70 71 ioarea = request_mem_region(mem->start, resource_size(mem), 72 pdev->name); 73 if (!ioarea) { 74 dev_err(&pdev->dev, "I2C region already claimed\n"); 75 return -EBUSY; 76 } 77 78 dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL); 79 if (!dev) { 80 r = -ENOMEM; 81 goto err_release_region; 82 } 83 84 init_completion(&dev->cmd_complete); 85 mutex_init(&dev->lock); 86 dev->dev = get_device(&pdev->dev); 87 dev->irq = irq; 88 platform_set_drvdata(pdev, dev); 89 90 dev->clk = clk_get(&pdev->dev, NULL); 91 dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; 92 93 if (IS_ERR(dev->clk)) { 94 r = -ENODEV; 95 goto err_free_mem; 96 } 97 clk_enable(dev->clk); 98 99 dev->functionality = 100 I2C_FUNC_I2C | 101 I2C_FUNC_10BIT_ADDR | 102 I2C_FUNC_SMBUS_BYTE | 103 I2C_FUNC_SMBUS_BYTE_DATA | 104 I2C_FUNC_SMBUS_WORD_DATA | 105 I2C_FUNC_SMBUS_I2C_BLOCK; 106 dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | 107 DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; 108 109 dev->base = ioremap(mem->start, resource_size(mem)); 110 if (dev->base == NULL) { 111 dev_err(&pdev->dev, "failure mapping io resources\n"); 112 r = -EBUSY; 113 goto err_unuse_clocks; 114 } 115 { 116 u32 param1 = i2c_dw_read_comp_param(dev); 117 118 dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; 119 dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; 120 } 121 r = i2c_dw_init(dev); 122 if (r) 123 goto err_iounmap; 124 125 i2c_dw_disable_int(dev); 126 r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev); 127 if (r) { 128 dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); 129 goto err_iounmap; 130 } 131 132 adap = &dev->adapter; 133 i2c_set_adapdata(adap, dev); 134 adap->owner = THIS_MODULE; 135 adap->class = I2C_CLASS_HWMON; 136 strlcpy(adap->name, "Synopsys DesignWare I2C adapter", 137 sizeof(adap->name)); 138 adap->algo = &i2c_dw_algo; 139 adap->dev.parent = &pdev->dev; 140 141 adap->nr = pdev->id; 142 r = i2c_add_numbered_adapter(adap); 143 if (r) { 144 dev_err(&pdev->dev, "failure adding adapter\n"); 145 goto err_free_irq; 146 } 147 148 return 0; 149 150 err_free_irq: 151 free_irq(dev->irq, dev); 152 err_iounmap: 153 iounmap(dev->base); 154 err_unuse_clocks: 155 clk_disable(dev->clk); 156 clk_put(dev->clk); 157 dev->clk = NULL; 158 err_free_mem: 159 platform_set_drvdata(pdev, NULL); 160 put_device(&pdev->dev); 161 kfree(dev); 162 err_release_region: 163 release_mem_region(mem->start, resource_size(mem)); 164 165 return r; 166 } 167 168 static int __devexit dw_i2c_remove(struct platform_device *pdev) 169 { 170 struct dw_i2c_dev *dev = platform_get_drvdata(pdev); 171 struct resource *mem; 172 173 platform_set_drvdata(pdev, NULL); 174 i2c_del_adapter(&dev->adapter); 175 put_device(&pdev->dev); 176 177 clk_disable(dev->clk); 178 clk_put(dev->clk); 179 dev->clk = NULL; 180 181 i2c_dw_disable(dev); 182 free_irq(dev->irq, dev); 183 kfree(dev); 184 185 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 186 release_mem_region(mem->start, resource_size(mem)); 187 return 0; 188 } 189 190 /* work with hotplug and coldplug */ 191 MODULE_ALIAS("platform:i2c_designware"); 192 193 static struct platform_driver dw_i2c_driver = { 194 .remove = __devexit_p(dw_i2c_remove), 195 .driver = { 196 .name = "i2c_designware", 197 .owner = THIS_MODULE, 198 }, 199 }; 200 201 static int __init dw_i2c_init_driver(void) 202 { 203 return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe); 204 } 205 module_init(dw_i2c_init_driver); 206 207 static void __exit dw_i2c_exit_driver(void) 208 { 209 platform_driver_unregister(&dw_i2c_driver); 210 } 211 module_exit(dw_i2c_exit_driver); 212 213 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); 214 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); 215 MODULE_LICENSE("GPL"); 216