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201 lines
4.6 KiB
201 lines
4.6 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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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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#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/jiffies.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 <linux/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 = 59000; |
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static struct i2c_adapter pca_isa_ops; |
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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(KERN_DEBUG "*** write %s at %#lx <= %#04x\n", names[reg], |
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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(KERN_DEBUG "*** 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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unsigned long timeout; |
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long ret; |
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if (irq > -1) { |
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ret = wait_event_timeout(pca_wait, |
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pca_isa_readbyte(pd, I2C_PCA_CON) |
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& I2C_PCA_CON_SI, pca_isa_ops.timeout); |
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} else { |
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/* Do polling */ |
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timeout = jiffies + pca_isa_ops.timeout; |
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do { |
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ret = time_before(jiffies, timeout); |
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if (pca_isa_readbyte(pd, I2C_PCA_CON) |
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& I2C_PCA_CON_SI) |
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break; |
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udelay(100); |
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} while (ret); |
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} |
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return ret > 0; |
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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(&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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.algo_data = &pca_isa_data, |
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.name = "PCA9564/PCA9665 ISA Adapter", |
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.timeout = HZ, |
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}; |
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static int 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 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 |
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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 void 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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} |
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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 = 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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MODULE_AUTHOR("Ian Campbell <[email protected]>"); |
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MODULE_DESCRIPTION("ISA base PCA9564/PCA9665 driver"); |
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MODULE_LICENSE("GPL"); |
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module_param_hw(base, ulong, ioport, 0); |
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MODULE_PARM_DESC(base, "I/O base address"); |
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module_param_hw(irq, int, irq, 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 in hertz.\n\t\t" |
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"For PCA9564: 330000,288000,217000,146000," |
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"88000,59000,44000,36000\n" |
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"\t\tFor PCA9665:\tStandard: 60300 - 100099\n" |
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"\t\t\t\tFast: 100100 - 400099\n" |
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"\t\t\t\tFast+: 400100 - 10000099\n" |
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"\t\t\t\tTurbo: Up to 1265800"); |
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module_isa_driver(pca_isa_driver, 1);
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