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 27 #include <asm/irq.h> 28 #include <asm/io.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 long ret = ~0; 84 unsigned long timeout; 85 86 if (i2c->irq) { 87 ret = wait_event_interruptible_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 while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) 94 & I2C_PCA_CON_SI) == 0) 95 && (ret = time_before(jiffies, timeout))) 96 udelay(100); 97 } 98 99 return ret > 0; 100 } 101 102 static void i2c_pca_pf_dummyreset(void *pd) 103 { 104 struct i2c_pca_pf_data *i2c = pd; 105 printk(KERN_WARNING "%s: No reset-pin found. Chip may get stuck!\n", 106 i2c->adap.name); 107 } 108 109 static void i2c_pca_pf_resetchip(void *pd) 110 { 111 struct i2c_pca_pf_data *i2c = pd; 112 113 gpio_set_value(i2c->gpio, 0); 114 ndelay(100); 115 gpio_set_value(i2c->gpio, 1); 116 } 117 118 static irqreturn_t i2c_pca_pf_handler(int this_irq, void *dev_id) 119 { 120 struct i2c_pca_pf_data *i2c = dev_id; 121 122 if ((i2c->algo_data.read_byte(i2c, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 123 return IRQ_NONE; 124 125 wake_up_interruptible(&i2c->wait); 126 127 return IRQ_HANDLED; 128 } 129 130 131 static int __devinit i2c_pca_pf_probe(struct platform_device *pdev) 132 { 133 struct i2c_pca_pf_data *i2c; 134 struct resource *res; 135 struct i2c_pca9564_pf_platform_data *platform_data = 136 pdev->dev.platform_data; 137 int ret = 0; 138 int irq; 139 140 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 141 irq = platform_get_irq(pdev, 0); 142 /* If irq is 0, we do polling. */ 143 144 if (res == NULL) { 145 ret = -ENODEV; 146 goto e_print; 147 } 148 149 if (!request_mem_region(res->start, resource_size(res), res->name)) { 150 ret = -ENOMEM; 151 goto e_print; 152 } 153 154 i2c = kzalloc(sizeof(struct i2c_pca_pf_data), GFP_KERNEL); 155 if (!i2c) { 156 ret = -ENOMEM; 157 goto e_alloc; 158 } 159 160 init_waitqueue_head(&i2c->wait); 161 162 i2c->reg_base = ioremap(res->start, resource_size(res)); 163 if (!i2c->reg_base) { 164 ret = -ENOMEM; 165 goto e_remap; 166 } 167 i2c->io_base = res->start; 168 i2c->io_size = resource_size(res); 169 i2c->irq = irq; 170 171 i2c->adap.nr = pdev->id >= 0 ? pdev->id : 0; 172 i2c->adap.owner = THIS_MODULE; 173 snprintf(i2c->adap.name, sizeof(i2c->adap.name), 174 "PCA9564/PCA9665 at 0x%08lx", 175 (unsigned long) res->start); 176 i2c->adap.algo_data = &i2c->algo_data; 177 i2c->adap.dev.parent = &pdev->dev; 178 179 if (platform_data) { 180 i2c->adap.timeout = platform_data->timeout; 181 i2c->algo_data.i2c_clock = platform_data->i2c_clock_speed; 182 i2c->gpio = platform_data->gpio; 183 } else { 184 i2c->adap.timeout = HZ; 185 i2c->algo_data.i2c_clock = 59000; 186 i2c->gpio = -1; 187 } 188 189 i2c->algo_data.data = i2c; 190 i2c->algo_data.wait_for_completion = i2c_pca_pf_waitforcompletion; 191 i2c->algo_data.reset_chip = i2c_pca_pf_dummyreset; 192 193 switch (res->flags & IORESOURCE_MEM_TYPE_MASK) { 194 case IORESOURCE_MEM_32BIT: 195 i2c->algo_data.write_byte = i2c_pca_pf_writebyte32; 196 i2c->algo_data.read_byte = i2c_pca_pf_readbyte32; 197 break; 198 case IORESOURCE_MEM_16BIT: 199 i2c->algo_data.write_byte = i2c_pca_pf_writebyte16; 200 i2c->algo_data.read_byte = i2c_pca_pf_readbyte16; 201 break; 202 case IORESOURCE_MEM_8BIT: 203 default: 204 i2c->algo_data.write_byte = i2c_pca_pf_writebyte8; 205 i2c->algo_data.read_byte = i2c_pca_pf_readbyte8; 206 break; 207 } 208 209 /* Use gpio_is_valid() when in mainline */ 210 if (i2c->gpio > -1) { 211 ret = gpio_request(i2c->gpio, i2c->adap.name); 212 if (ret == 0) { 213 gpio_direction_output(i2c->gpio, 1); 214 i2c->algo_data.reset_chip = i2c_pca_pf_resetchip; 215 } else { 216 printk(KERN_WARNING "%s: Registering gpio failed!\n", 217 i2c->adap.name); 218 i2c->gpio = ret; 219 } 220 } 221 222 if (irq) { 223 ret = request_irq(irq, i2c_pca_pf_handler, 224 IRQF_TRIGGER_FALLING, i2c->adap.name, i2c); 225 if (ret) 226 goto e_reqirq; 227 } 228 229 if (i2c_pca_add_numbered_bus(&i2c->adap) < 0) { 230 ret = -ENODEV; 231 goto e_adapt; 232 } 233 234 platform_set_drvdata(pdev, i2c); 235 236 printk(KERN_INFO "%s registered.\n", i2c->adap.name); 237 238 return 0; 239 240 e_adapt: 241 if (irq) 242 free_irq(irq, i2c); 243 e_reqirq: 244 if (i2c->gpio > -1) 245 gpio_free(i2c->gpio); 246 247 iounmap(i2c->reg_base); 248 e_remap: 249 kfree(i2c); 250 e_alloc: 251 release_mem_region(res->start, resource_size(res)); 252 e_print: 253 printk(KERN_ERR "Registering PCA9564/PCA9665 FAILED! (%d)\n", ret); 254 return ret; 255 } 256 257 static int __devexit i2c_pca_pf_remove(struct platform_device *pdev) 258 { 259 struct i2c_pca_pf_data *i2c = platform_get_drvdata(pdev); 260 platform_set_drvdata(pdev, NULL); 261 262 i2c_del_adapter(&i2c->adap); 263 264 if (i2c->irq) 265 free_irq(i2c->irq, i2c); 266 267 if (i2c->gpio > -1) 268 gpio_free(i2c->gpio); 269 270 iounmap(i2c->reg_base); 271 release_mem_region(i2c->io_base, i2c->io_size); 272 kfree(i2c); 273 274 return 0; 275 } 276 277 static struct platform_driver i2c_pca_pf_driver = { 278 .probe = i2c_pca_pf_probe, 279 .remove = __devexit_p(i2c_pca_pf_remove), 280 .driver = { 281 .name = "i2c-pca-platform", 282 .owner = THIS_MODULE, 283 }, 284 }; 285 286 static int __init i2c_pca_pf_init(void) 287 { 288 return platform_driver_register(&i2c_pca_pf_driver); 289 } 290 291 static void __exit i2c_pca_pf_exit(void) 292 { 293 platform_driver_unregister(&i2c_pca_pf_driver); 294 } 295 296 MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>"); 297 MODULE_DESCRIPTION("I2C-PCA9564/PCA9665 platform driver"); 298 MODULE_LICENSE("GPL"); 299 300 module_init(i2c_pca_pf_init); 301 module_exit(i2c_pca_pf_exit); 302 303