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/pci.h> 29 #include <linux/wait.h> 30 31 #include <linux/isa.h> 32 #include <linux/i2c.h> 33 #include <linux/i2c-algo-pca.h> 34 35 #include <asm/io.h> 36 #include <asm/irq.h> 37 38 #include "../algos/i2c-algo-pca.h" 39 40 #define IO_SIZE 4 41 42 #undef DEBUG_IO 43 //#define DEBUG_IO 44 45 static unsigned long base = 0x330; 46 static int irq = 10; 47 48 /* Data sheet recommends 59kHz for 100kHz operation due to variation 49 * in the actual clock rate */ 50 static int clock = I2C_PCA_CON_59kHz; 51 52 static int own = 0x55; 53 54 static wait_queue_head_t pca_wait; 55 56 static int pca_isa_getown(struct i2c_algo_pca_data *adap) 57 { 58 return (own); 59 } 60 61 static int pca_isa_getclock(struct i2c_algo_pca_data *adap) 62 { 63 return (clock); 64 } 65 66 static void 67 pca_isa_writebyte(struct i2c_algo_pca_data *adap, int reg, int val) 68 { 69 #ifdef DEBUG_IO 70 static char *names[] = { "T/O", "DAT", "ADR", "CON" }; 71 printk("*** write %s at %#lx <= %#04x\n", names[reg], base+reg, val); 72 #endif 73 outb(val, base+reg); 74 } 75 76 static int 77 pca_isa_readbyte(struct i2c_algo_pca_data *adap, int reg) 78 { 79 int res = inb(base+reg); 80 #ifdef DEBUG_IO 81 { 82 static char *names[] = { "STA", "DAT", "ADR", "CON" }; 83 printk("*** read %s => %#04x\n", names[reg], res); 84 } 85 #endif 86 return res; 87 } 88 89 static int pca_isa_waitforinterrupt(struct i2c_algo_pca_data *adap) 90 { 91 int ret = 0; 92 93 if (irq > -1) { 94 ret = wait_event_interruptible(pca_wait, 95 pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI); 96 } else { 97 while ((pca_isa_readbyte(adap, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0) 98 udelay(100); 99 } 100 return ret; 101 } 102 103 static irqreturn_t pca_handler(int this_irq, void *dev_id) { 104 wake_up_interruptible(&pca_wait); 105 return IRQ_HANDLED; 106 } 107 108 static struct i2c_algo_pca_data pca_isa_data = { 109 .get_own = pca_isa_getown, 110 .get_clock = pca_isa_getclock, 111 .write_byte = pca_isa_writebyte, 112 .read_byte = pca_isa_readbyte, 113 .wait_for_interrupt = pca_isa_waitforinterrupt, 114 }; 115 116 static struct i2c_adapter pca_isa_ops = { 117 .owner = THIS_MODULE, 118 .id = I2C_HW_A_ISA, 119 .algo_data = &pca_isa_data, 120 .name = "PCA9564 ISA Adapter", 121 }; 122 123 static int __devinit pca_isa_probe(struct device *dev, unsigned int id) 124 { 125 init_waitqueue_head(&pca_wait); 126 127 dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq); 128 129 if (!request_region(base, IO_SIZE, "i2c-pca-isa")) { 130 dev_err(dev, "I/O address %#08lx is in use\n", base); 131 goto out; 132 } 133 134 if (irq > -1) { 135 if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) { 136 dev_err(dev, "Request irq%d failed\n", irq); 137 goto out_region; 138 } 139 } 140 141 if (i2c_pca_add_bus(&pca_isa_ops) < 0) { 142 dev_err(dev, "Failed to add i2c bus\n"); 143 goto out_irq; 144 } 145 146 return 0; 147 148 out_irq: 149 if (irq > -1) 150 free_irq(irq, &pca_isa_ops); 151 out_region: 152 release_region(base, IO_SIZE); 153 out: 154 return -ENODEV; 155 } 156 157 static int __devexit pca_isa_remove(struct device *dev, unsigned int id) 158 { 159 i2c_del_adapter(&pca_isa_ops); 160 161 if (irq > 0) { 162 disable_irq(irq); 163 free_irq(irq, &pca_isa_ops); 164 } 165 release_region(base, IO_SIZE); 166 167 return 0; 168 } 169 170 static struct isa_driver pca_isa_driver = { 171 .probe = pca_isa_probe, 172 .remove = __devexit_p(pca_isa_remove), 173 .driver = { 174 .owner = THIS_MODULE, 175 .name = "i2c-pca-isa", 176 } 177 }; 178 179 static int __init pca_isa_init(void) 180 { 181 return isa_register_driver(&pca_isa_driver, 1); 182 } 183 184 static void __exit pca_isa_exit(void) 185 { 186 isa_unregister_driver(&pca_isa_driver); 187 } 188 189 MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>"); 190 MODULE_DESCRIPTION("ISA base PCA9564 driver"); 191 MODULE_LICENSE("GPL"); 192 193 module_param(base, ulong, 0); 194 MODULE_PARM_DESC(base, "I/O base address"); 195 196 module_param(irq, int, 0); 197 MODULE_PARM_DESC(irq, "IRQ"); 198 module_param(clock, int, 0); 199 MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet"); 200 201 module_param(own, int, 0); /* the driver can't do slave mode, so there's no real point in this */ 202 203 module_init(pca_isa_init); 204 module_exit(pca_isa_exit); 205