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