1 /* 2 * i2c_pca_platform.c 3 * 4 * Platform driver for the PCA9564 I2C controller. 5 * 6 * Copyright (C) 2008 Pengutronix 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 12 */ 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/slab.h> 17 #include <linux/delay.h> 18 #include <linux/jiffies.h> 19 #include <linux/errno.h> 20 #include <linux/i2c.h> 21 #include <linux/interrupt.h> 22 #include <linux/platform_device.h> 23 #include <linux/i2c-algo-pca.h> 24 #include <linux/i2c-pca-platform.h> 25 #include <linux/gpio.h> 26 #include <linux/io.h> 27 28 #include <asm/irq.h> 29 30 struct i2c_pca_pf_data { 31 void __iomem *reg_base; 32 int irq; /* if 0, use polling */ 33 int gpio; 34 wait_queue_head_t wait; 35 struct i2c_adapter adap; 36 struct i2c_algo_pca_data algo_data; 37 unsigned long io_base; 38 unsigned long io_size; 39 }; 40 41 /* Read/Write functions for different register alignments */ 42 43 static int i2c_pca_pf_readbyte8(void *pd, int reg) 44 { 45 struct i2c_pca_pf_data *i2c = pd; 46 return ioread8(i2c->reg_base + reg); 47 } 48 49 static int i2c_pca_pf_readbyte16(void *pd, int reg) 50 { 51 struct i2c_pca_pf_data *i2c = pd; 52 return ioread8(i2c->reg_base + reg * 2); 53 } 54 55 static int i2c_pca_pf_readbyte32(void *pd, int reg) 56 { 57 struct i2c_pca_pf_data *i2c = pd; 58 return ioread8(i2c->reg_base + reg * 4); 59 } 60 61 static void i2c_pca_pf_writebyte8(void *pd, int reg, int val) 62 { 63 struct i2c_pca_pf_data *i2c = pd; 64 iowrite8(val, i2c->reg_base + reg); 65 } 66 67 static void i2c_pca_pf_writebyte16(void *pd, int reg, int val) 68 { 69 struct i2c_pca_pf_data *i2c = pd; 70 iowrite8(val, i2c->reg_base + reg * 2); 71 } 72 73 static void i2c_pca_pf_writebyte32(void *pd, int reg, int val) 74 { 75 struct i2c_pca_pf_data *i2c = pd; 76 iowrite8(val, i2c->reg_base + reg * 4); 77 } 78 79 80 static int i2c_pca_pf_waitforcompletion(void *pd) 81 { 82 struct i2c_pca_pf_data *i2c = pd; 83 unsigned long timeout; 84 long ret; 85 86 if (i2c->irq) { 87 ret = wait_event_timeout(i2c->wait, 88 i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 89 & I2C_PCA_CON_SI, i2c->adap.timeout); 90 } else { 91 /* Do polling */ 92 timeout = jiffies + i2c->adap.timeout; 93 do { 94 ret = time_before(jiffies, timeout); 95 if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 96 & I2C_PCA_CON_SI) 97 break; 98 udelay(100); 99 } while (ret); 100 } 101 102 return ret > 0; 103 } 104 105 static void i2c_pca_pf_dummyreset(void *pd) 106 { 107 struct i2c_pca_pf_data *i2c = pd; 108 printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n", 109 i2c->adap.name); 110 } 111 112 static void i2c_pca_pf_resetchip(void *pd) 113 { 114 struct i2c_pca_pf_data *i2c = pd; 115 116 gpio_set_value(i2c->gpio, 0); 117 ndelay(100); 118 gpio_set_value(i2c->gpio, 1); 119 } 120 121 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id) 122 { 123 struct i2c_pca_pf_data *i2c = dev_id; 124 125 if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 126 return IRQ_NONE; 127 128 wake_up(&i2c->wait); 129 130 return IRQ_HANDLED; 131 } 132 133 134 static int __devinit i2c_pca_pf_probe(struct platform_device *pdev) 135 { 136 struct i2c_pca_pf_data *i2c; 137 struct resource *res; 138 struct i2c_pca9564_pf_platform_data *platform_data = 139 pdev->dev.platform_data; 140 int ret = 0; 141 int irq; 142 143 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 144 irq = platform_get_irq(pdev, 0); 145 /* If irq is 0, we do polling. */ 146 147 if (res == NULL) { 148 ret = -ENODEV; 149 goto e_print; 150 } 151 152 if (!request_mem_region(res->start, resource_size(res), res->name)) { 153 ret = -ENOMEM; 154 goto e_print; 155 } 156 157 i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL); 158 if (!i2c) { 159 ret = -ENOMEM; 160 goto e_alloc; 161 } 162 163 init_waitqueue_head(&i2c->wait); 164 165 i2c->reg_base = ioremap(res->start, resource_size(res)); 166 if (!i2c->reg_base) { 167 ret = -ENOMEM; 168 goto e_remap; 169 } 170 i2c->io_base = res->start; 171 i2c->io_size = resource_size(res); 172 i2c->irq = irq; 173 174 i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0; 175 i2c->adap.owner = THIS_MODULE; 176 snprintf(i2c->adap.name, sizeof(i2c->adap.name), 177 "PCA9564/PCA9665 at 0x%08lx", 178 (unsigned long) res->start); 179 i2c->adap.algo_data = &i2c->algo_data; 180 i2c->adap.dev.parent = &pdev->dev; 181 182 if (platform_data) { 183 i2c->adap.timeout = platform_data->timeout; 184 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; 185 i2c->gpio = platform_data->gpio; 186 } else { 187 i2c->adap.timeout = HZ; 188 i2c->algo_data.i2c_clock = 59000; 189 i2c->gpio = -1; 190 } 191 192 i2c->algo_data.data = i2c; 193 i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; 194 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; 195 196 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) { 197 case IORESOURCE_MEM_32BIT: 198 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32; 199 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32; 200 break; 201 case IORESOURCE_MEM_16BIT: 202 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16; 203 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16; 204 break; 205 case IORESOURCE_MEM_8BIT: 206 default: 207 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8; 208 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8; 209 break; 210 } 211 212 /* Use gpio_is_valid() when in mainline */ 213 if (i2c->gpio > -1) { 214 ret = gpio_request(i2c->gpio, i2c->adap.name); 215 if (ret == 0) { 216 gpio_direction_output(i2c->gpio, 1); 217 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip; 218 } else { 219 printk(KERN_WARNING "%s: Registering gpio failed!\n", 220 i2c->adap.name); 221 i2c->gpio = ret; 222 } 223 } 224 225 if (irq) { 226 ret = request_irq(irq, i2c_pca_pf_handler, 227 IRQF_TRIGGER_FALLING, pdev->name, i2c); 228 if (ret) 229 goto e_reqirq; 230 } 231 232 if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) { 233 ret = -ENODEV; 234 goto e_adapt; 235 } 236 237 platform_set_drvdata(pdev, i2c); 238 239 printk(KERN_INFO "%s registered.\n", i2c->adap.name); 240 241 return 0; 242 243 e_adapt: 244 if (irq) 245 free_irq(irq, i2c); 246 e_reqirq: 247 if (i2c->gpio > -1) 248 gpio_free(i2c->gpio); 249 250 iounmap(i2c->reg_base); 251 e_remap: 252 kfree(i2c); 253 e_alloc: 254 release_mem_region(res->start, resource_size(res)); 255 e_print: 256 printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); 257 return ret; 258 } 259 260 static int __devexit i2c_pca_pf_remove(struct platform_device *pdev) 261 { 262 struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); 263 platform_set_drvdata(pdev, NULL); 264 265 i2c_del_adapter(&i2c->adap); 266 267 if (i2c->irq) 268 free_irq(i2c->irq, i2c); 269 270 if (i2c->gpio > -1) 271 gpio_free(i2c->gpio); 272 273 iounmap(i2c->reg_base); 274 release_mem_region(i2c->io_base, i2c->io_size); 275 kfree(i2c); 276 277 return 0; 278 } 279 280 static struct platform_driver i2c_pca_pf_driver = { 281 .probe = i2c_pca_pf_probe, 282 .remove = __devexit_p(i2c_pca_pf_remove), 283 .driver = { 284 .name = "i2c-pca-platform", 285 .owner = THIS_MODULE, 286 }, 287 }; 288 289 static int __init i2c_pca_pf_init(void) 290 { 291 return platform_driver_register(&i2c_pca_pf_driver); 292 } 293 294 static void __exit i2c_pca_pf_exit(void) 295 { 296 platform_driver_unregister(&i2c_pca_pf_driver); 297 } 298 299 MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); 300 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); 301 MODULE_LICENSE("GPL"); 302 303 module_init(i2c_pca_pf_init); 304 module_exit(i2c_pca_pf_exit); 305 306