--- /dev/null
+/*
+ * i2c-pca-isa.c driver for PCA9564 on ISA boards
+ * Copyright (C) 2004 Arcom Control Systems
+ * Copyright (C) 2008 Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/isa.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-pca.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+
+#define DRIVER "i2c-pca-isa"
+#define IO_SIZE 4
+
+static unsigned long base;
+static int irq = -1;
+
+/* Data sheet recommends 59kHz for 100kHz operation due to variation
+ * in the actual clock rate */
+static int clock = 59000;
+
+static struct i2c_adapter pca_isa_ops;
+static wait_queue_head_t pca_wait;
+
+static void pca_isa_writebyte(void *pd, int reg, int val)
+{
+#ifdef DEBUG_IO
+ static char *names[] = { "T/O", "DAT", "ADR", "CON" };
+ printk(KERN_DEBUG "*** write %s at %#lx <= %#04x\n", names[reg],
+ base+reg, val);
+#endif
+ outb(val, base+reg);
+}
+
+static int pca_isa_readbyte(void *pd, int reg)
+{
+ int res = inb(base+reg);
+#ifdef DEBUG_IO
+ {
+ static char *names[] = { "STA", "DAT", "ADR", "CON" };
+ printk(KERN_DEBUG "*** read %s => %#04x\n", names[reg], res);
+ }
+#endif
+ return res;
+}
+
+static int pca_isa_waitforcompletion(void *pd)
+{
+ unsigned long timeout;
+ long ret;
+
+ if (irq > -1) {
+ ret = wait_event_timeout(pca_wait,
+ pca_isa_readbyte(pd, I2C_PCA_CON)
+ & I2C_PCA_CON_SI, pca_isa_ops.timeout);
+ } else {
+ /* Do polling */
+ timeout = jiffies + pca_isa_ops.timeout;
+ do {
+ ret = time_before(jiffies, timeout);
+ if (pca_isa_readbyte(pd, I2C_PCA_CON)
+ & I2C_PCA_CON_SI)
+ break;
+ udelay(100);
+ } while (ret);
+ }
+
+ return ret > 0;
+}
+
+static void pca_isa_resetchip(void *pd)
+{
+ /* apparently only an external reset will do it. not a lot can be done */
+ printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n");
+}
+
+static irqreturn_t pca_handler(int this_irq, void *dev_id) {
+ wake_up(&pca_wait);
+ return IRQ_HANDLED;
+}
+
+static struct i2c_algo_pca_data pca_isa_data = {
+ /* .data intentionally left NULL, not needed with ISA */
+ .write_byte = pca_isa_writebyte,
+ .read_byte = pca_isa_readbyte,
+ .wait_for_completion = pca_isa_waitforcompletion,
+ .reset_chip = pca_isa_resetchip,
+};
+
+static struct i2c_adapter pca_isa_ops = {
+ .owner = THIS_MODULE,
+ .algo_data = &pca_isa_data,
+ .name = "PCA9564/PCA9665 ISA Adapter",
+ .timeout = HZ,
+};
+
+static int pca_isa_match(struct device *dev, unsigned int id)
+{
+ int match = base != 0;
+
+ if (match) {
+ if (irq <= -1)
+ dev_warn(dev, "Using polling mode (specify irq)\n");
+ } else
+ dev_err(dev, "Please specify I/O base\n");
+
+ return match;
+}
+
+static int pca_isa_probe(struct device *dev, unsigned int id)
+{
+ init_waitqueue_head(&pca_wait);
+
+ dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq);
+
+#ifdef CONFIG_PPC
+ if (check_legacy_ioport(base)) {
+ dev_err(dev, "I/O address %#08lx is not available\n", base);
+ goto out;
+ }
+#endif
+
+ if (!request_region(base, IO_SIZE, "i2c-pca-isa")) {
+ dev_err(dev, "I/O address %#08lx is in use\n", base);
+ goto out;
+ }
+
+ if (irq > -1) {
+ if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) {
+ dev_err(dev, "Request irq%d failed\n", irq);
+ goto out_region;
+ }
+ }
+
+ pca_isa_data.i2c_clock = clock;
+ if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
+ dev_err(dev, "Failed to add i2c bus\n");
+ goto out_irq;
+ }
+
+ return 0;
+
+ out_irq:
+ if (irq > -1)
+ free_irq(irq, &pca_isa_ops);
+ out_region:
+ release_region(base, IO_SIZE);
+ out:
+ return -ENODEV;
+}
+
+static int pca_isa_remove(struct device *dev, unsigned int id)
+{
+ i2c_del_adapter(&pca_isa_ops);
+
+ if (irq > -1) {
+ disable_irq(irq);
+ free_irq(irq, &pca_isa_ops);
+ }
+ release_region(base, IO_SIZE);
+
+ return 0;
+}
+
+static struct isa_driver pca_isa_driver = {
+ .match = pca_isa_match,
+ .probe = pca_isa_probe,
+ .remove = pca_isa_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRIVER,
+ }
+};
+
+static int __init pca_isa_init(void)
+{
+ return isa_register_driver(&pca_isa_driver, 1);
+}
+
+static void __exit pca_isa_exit(void)
+{
+ isa_unregister_driver(&pca_isa_driver);
+}
+
+MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
+MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver");
+MODULE_LICENSE("GPL");
+
+module_param(base, ulong, 0);
+MODULE_PARM_DESC(base, "I/O base address");
+
+module_param(irq, int, 0);
+MODULE_PARM_DESC(irq, "IRQ");
+module_param(clock, int, 0);
+MODULE_PARM_DESC(clock, "Clock rate in hertz.\n\t\t"
+ "For PCA9564: 330000,288000,217000,146000,"
+ "88000,59000,44000,36000\n"
+ "\t\tFor PCA9665:\tStandard: 60300 - 100099\n"
+ "\t\t\t\tFast: 100100 - 400099\n"
+ "\t\t\t\tFast+: 400100 - 10000099\n"
+ "\t\t\t\tTurbo: Up to 1265800");
+
+module_init(pca_isa_init);
+module_exit(pca_isa_exit);
Code Review / kvmfornfv.git / blobdiff