forked from luck/tmp_suning_uos_patched
ce5640330b
Grabbing ISA bus resources without anything or anyone telling us we should can break boot on randconfig/allyesconfig builds by keeping resources that are in fact owned by different hardware busy and does as reported by Ingo Molnar. Generally it's also dangerous to just poke at random I/O ports and especially those in the range where other old easily confused ISA hardware might live. For this specialized I2C bus driver, insist that the user specifies the resources before grabbing them. The^WA user of this driver is a one time echo "options i2c-pca-isa base=0x330 irq=10" >> /etc/modprobe.conf away from the old behaviour. Signed-off-by: Rene Herman <rene.herman@gmail.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
212 lines
5.0 KiB
C
212 lines
5.0 KiB
C
/*
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* i2c-pca-isa.c driver for PCA9564 on ISA boards
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* Copyright (C) 2004 Arcom Control Systems
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* Copyright (C) 2008 Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/kernel.h>
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#include <linux/ioport.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/wait.h>
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#include <linux/isa.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-pca.h>
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#include <asm/io.h>
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#include <asm/irq.h>
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#define DRIVER "i2c-pca-isa"
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#define IO_SIZE 4
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static unsigned long base;
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static int irq = -1;
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/* Data sheet recommends 59kHz for 100kHz operation due to variation
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* in the actual clock rate */
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static int clock = I2C_PCA_CON_59kHz;
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static wait_queue_head_t pca_wait;
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static void pca_isa_writebyte(void *pd, int reg, int val)
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{
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#ifdef DEBUG_IO
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static char *names[] = { "T/O", "DAT", "ADR", "CON" };
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printk("*** write %s at %#lx <= %#04x\n", names[reg], base+reg, val);
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#endif
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outb(val, base+reg);
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}
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static int pca_isa_readbyte(void *pd, int reg)
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{
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int res = inb(base+reg);
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#ifdef DEBUG_IO
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{
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static char *names[] = { "STA", "DAT", "ADR", "CON" };
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printk("*** read %s => %#04x\n", names[reg], res);
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}
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#endif
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return res;
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}
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static int pca_isa_waitforcompletion(void *pd)
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{
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int ret = 0;
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if (irq > -1) {
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ret = wait_event_interruptible(pca_wait,
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pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI);
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} else {
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while ((pca_isa_readbyte(pd, I2C_PCA_CON) & I2C_PCA_CON_SI) == 0)
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udelay(100);
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}
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return ret;
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}
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static void pca_isa_resetchip(void *pd)
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{
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/* apparently only an external reset will do it. not a lot can be done */
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printk(KERN_WARNING DRIVER ": Haven't figured out how to do a reset yet\n");
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}
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static irqreturn_t pca_handler(int this_irq, void *dev_id) {
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wake_up_interruptible(&pca_wait);
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return IRQ_HANDLED;
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}
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static struct i2c_algo_pca_data pca_isa_data = {
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/* .data intentionally left NULL, not needed with ISA */
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.write_byte = pca_isa_writebyte,
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.read_byte = pca_isa_readbyte,
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.wait_for_completion = pca_isa_waitforcompletion,
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.reset_chip = pca_isa_resetchip,
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};
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static struct i2c_adapter pca_isa_ops = {
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.owner = THIS_MODULE,
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.id = I2C_HW_A_ISA,
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.algo_data = &pca_isa_data,
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.name = "PCA9564 ISA Adapter",
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.timeout = 100,
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};
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static int __devinit pca_isa_match(struct device *dev, unsigned int id)
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{
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int match = base != 0;
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if (match) {
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if (irq <= -1)
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dev_warn(dev, "Using polling mode (specify irq)\n");
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} else
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dev_err(dev, "Please specify I/O base\n");
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return match;
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}
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static int __devinit pca_isa_probe(struct device *dev, unsigned int id)
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{
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init_waitqueue_head(&pca_wait);
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dev_info(dev, "i/o base %#08lx. irq %d\n", base, irq);
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#ifdef CONFIG_PPC_MERGE
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if (check_legacy_ioport(base)) {
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dev_err(dev, "I/O address %#08lx is not available\n", base);
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goto out;
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}
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#endif
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if (!request_region(base, IO_SIZE, "i2c-pca-isa")) {
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dev_err(dev, "I/O address %#08lx is in use\n", base);
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goto out;
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}
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if (irq > -1) {
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if (request_irq(irq, pca_handler, 0, "i2c-pca-isa", &pca_isa_ops) < 0) {
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dev_err(dev, "Request irq%d failed\n", irq);
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goto out_region;
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}
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}
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pca_isa_data.i2c_clock = clock;
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if (i2c_pca_add_bus(&pca_isa_ops) < 0) {
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dev_err(dev, "Failed to add i2c bus\n");
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goto out_irq;
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}
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return 0;
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out_irq:
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if (irq > -1)
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free_irq(irq, &pca_isa_ops);
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out_region:
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release_region(base, IO_SIZE);
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out:
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return -ENODEV;
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}
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static int __devexit pca_isa_remove(struct device *dev, unsigned int id)
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{
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i2c_del_adapter(&pca_isa_ops);
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if (irq > -1) {
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disable_irq(irq);
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free_irq(irq, &pca_isa_ops);
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}
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release_region(base, IO_SIZE);
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return 0;
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}
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static struct isa_driver pca_isa_driver = {
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.match = pca_isa_match,
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.probe = pca_isa_probe,
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.remove = __devexit_p(pca_isa_remove),
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.driver = {
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.owner = THIS_MODULE,
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.name = DRIVER,
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}
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};
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static int __init pca_isa_init(void)
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{
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return isa_register_driver(&pca_isa_driver, 1);
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}
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static void __exit pca_isa_exit(void)
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{
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isa_unregister_driver(&pca_isa_driver);
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}
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MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
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MODULE_DESCRIPTION("ISA base PCA9564 driver");
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MODULE_LICENSE("GPL");
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module_param(base, ulong, 0);
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MODULE_PARM_DESC(base, "I/O base address");
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module_param(irq, int, 0);
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MODULE_PARM_DESC(irq, "IRQ");
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module_param(clock, int, 0);
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MODULE_PARM_DESC(clock, "Clock rate as described in table 1 of PCA9564 datasheet");
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module_init(pca_isa_init);
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module_exit(pca_isa_exit);
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