1 /* 2 * i2c-pca-isa.c driver for PCA9564 on ISA boards 3 * Copyright (C) 2004 Arcom Control Systems 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/ioport.h> 22 #include <linux/module.h> 23 #include <linux/moduleparam.h> 24 #include <linux/delay.h> 25 #include <linux/slab.h> 26 #include <linux/init.h> 27 #include <linux/interrupt.h> 28 #include <linux/wait.h> 29 30 #include <linux/isa.h> 31 #include <linux/i2c.h> 32 #include <linux/i2c-algo-pca.h> 33 34 #include <asm/io.h> 35 #include <asm/irq.h> 36 37 #include "../algos/i2c-algo-pca.h" 38 39 #define IO_SIZE 4 40 41 #undef DEBUG_IO 42 //#define DEBUG_IO 43 44 static unsigned long base = 0x330; 45 static int irq = 10; 46 47 /* Data sheet recommends 59kHz for 100kHz operation due to variation 48 * in the actual clock rate */ 49 static int clock = I2C_PCA_CON_59kHz; 50 51 static int own = 0x55; 52 53 static wait_queue_head_t pca_wait; 54 55 static int pca_isa_getown(struct i2c_algo_pca_data *adap) 56 { 57 return (own); 58 } 59 60 static int pca_isa_getclock(struct i2c_algo_pca_data *adap) 61 { 62 return (clock); 63 } 64 65 static void 66 pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val) 67 { 68 #ifdef DEBUG_IO 69 static char *names[] = { "T/O", "DAT", "ADR", "CON" }; 70 printk("*** write %s at %#lx <= %#04x\n", names[reg], base+reg, val); 71 #endif 72 outb(val, base+reg); 73 } 74 75 static int 76 pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) 77 { 78 int res = inb(base+reg); 79 #ifdef DEBUG_IO 80 { 81 static char *names[] = { "STA", "DAT", "ADR", "CON" }; 82 printk("*** read %s => %#04x\n", names[reg], res); 83 } 84 #endif 85 return res; 86 } 87 88 static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap) 89 { 90 int ret = 0; 91 92 if (irq > -1) { 93 ret = wait_event_interruptible(pca_wait, 94 pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI); 95 } else { 96 while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 97 udelay(100); 98 } 99 return ret; 100 } 101 102 static irqreturn_t pca_handler(int this_irq, void *dev_id) { 103 wake_up_interruptible(&pca_wait); 104 return IRQ_HANDLED; 105 } 106 107 static struct i2c_algo_pca_data pca_isa_data = { 108 .get_own = pca_isa_getown, 109 .get_clock = pca_isa_getclock, 110 .write_byte = pca_isa_writebyte, 111 .read_byte = pca_isa_readbyte, 112 .wait_for_interrupt = pca_isa_waitforinterrupt, 113 }; 114 115 static struct i2c_adapter pca_isa_ops = { 116 .owner = THIS_MODULE, 117 .id = I2C_HW_A_ISA, 118 .algo_data = &pca_isa_data, 119 .name = "PCA9564 ISA Adapter", 120 }; 121 122 static int __devinit pca_isa_probe(struct device *dev, unsigned int id) 123 { 124 init_waitqueue_head(&pca_wait); 125 126 dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq); 127 128 #ifdef CONFIG_PPC_MERGE 129 if (check_legacy_ioport(base)) { 130 dev_err(dev, "I/O address %#08lx is not available\n", base); 131 goto out; 132 } 133 #endif 134 135 if (!request_region(base, IO_SIZE, "i2c-pca-isa")) { 136 dev_err(dev, "I/O address %#08lx is in use\n", base); 137 goto out; 138 } 139 140 if (irq > -1) { 141 if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) { 142 dev_err(dev, "Request irq%d failed\n", irq); 143 goto out_region; 144 } 145 } 146 147 if (i2c_pca_add_bus(&pca_isa_ops) < 0) { 148 dev_err(dev, "Failed to add i2c bus\n"); 149 goto out_irq; 150 } 151 152 return 0; 153 154 out_irq: 155 if (irq > -1) 156 free_irq(irq, &pca_isa_ops); 157 out_region: 158 release_region(base, IO_SIZE); 159 out: 160 return -ENODEV; 161 } 162 163 static int __devexit pca_isa_remove(struct device *dev, unsigned int id) 164 { 165 i2c_del_adapter(&pca_isa_ops); 166 167 if (irq > 0) { 168 disable_irq(irq); 169 free_irq(irq, &pca_isa_ops); 170 } 171 release_region(base, IO_SIZE); 172 173 return 0; 174 } 175 176 static struct isa_driver pca_isa_driver = { 177 .probe = pca_isa_probe, 178 .remove = __devexit_p(pca_isa_remove), 179 .driver = { 180 .owner = THIS_MODULE, 181 .name = "i2c-pca-isa", 182 } 183 }; 184 185 static int __init pca_isa_init(void) 186 { 187 return isa_register_driver(&pca_isa_driver, 1); 188 } 189 190 static void __exit pca_isa_exit(void) 191 { 192 isa_unregister_driver(&pca_isa_driver); 193 } 194 195 MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>"); 196 MODULE_DESCRIPTION("ISA base PCA9564 driver"); 197 MODULE_LICENSE("GPL"); 198 199 module_param(base, ulong, 0); 200 MODULE_PARM_DESC(base, "I/O base address"); 201 202 module_param(irq, int, 0); 203 MODULE_PARM_DESC(irq, "IRQ"); 204 module_param(clock, int, 0); 205 MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet"); 206 207 module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */ 208 209 module_init(pca_isa_init); 210 module_exit(pca_isa_exit); 211