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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* matrox_w1.c
*
* Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
*/
#include <asm/types.h>
#include <linux/atomic.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/pci_ids.h>
#include <linux/pci.h>
#include <linux/w1.h>
/*
* Matrox G400 DDC registers.
*/
#define MATROX_G400_DDC_CLK (1<<4)
#define MATROX_G400_DDC_DATA (1<<1)
#define MATROX_BASE 0x3C00
#define MATROX_STATUS 0x1e14
#define MATROX_PORT_INDEX_OFFSET 0x00
#define MATROX_PORT_DATA_OFFSET 0x0A
#define MATROX_GET_CONTROL 0x2A
#define MATROX_GET_DATA 0x2B
#define MATROX_CURSOR_CTL 0x06
struct matrox_device {
void __iomem *base_addr;
void __iomem *port_index;
void __iomem *port_data;
u8 data_mask;
unsigned long phys_addr;
void __iomem *virt_addr;
unsigned long found;
struct w1_bus_master *bus_master;
};
/*
* These functions read and write DDC Data bit.
*
* Using tristate pins, since i can't find any open-drain pin in whole motherboard.
* Unfortunately we can't connect to Intel's 82801xx IO controller
* since we don't know motherboard schema, which has pretty unused(may be not) GPIO.
*
* I've heard that PIIX also has open drain pin.
*
* Port mapping.
*/
static inline u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)
{
u8 ret;
writeb(reg, dev->port_index);
ret = readb(dev->port_data);
barrier();
return ret;
}
static inline void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)
{
writeb(reg, dev->port_index);
writeb(val, dev->port_data);
wmb();
}
static void matrox_w1_write_ddc_bit(void *data, u8 bit)
{
u8 ret;
struct matrox_device *dev = data;
if (bit)
bit = 0;
else
bit = dev->data_mask;
ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);
matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));
matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);
}
static u8 matrox_w1_read_ddc_bit(void *data)
{
u8 ret;
struct matrox_device *dev = data;
ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);
return ret;
}
static void matrox_w1_hw_init(struct matrox_device *dev)
{
matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);
matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);
}
static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
struct matrox_device *dev;
int err;
if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)
return -ENODEV;
dev = kzalloc(sizeof(struct matrox_device) +
sizeof(struct w1_bus_master), GFP_KERNEL);
if (!dev)
return -ENOMEM;
dev->bus_master = (struct w1_bus_master *)(dev + 1);
/*
* True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c
*/
dev->phys_addr = pci_resource_start(pdev, 1);
dev->virt_addr = ioremap(dev->phys_addr, 16384);
if (!dev->virt_addr) {
dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",
__func__, dev->phys_addr, 16384);
err = -EIO;
goto err_out_free_device;
}
dev->base_addr = dev->virt_addr + MATROX_BASE;
dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;
dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;
dev->data_mask = (MATROX_G400_DDC_DATA);
matrox_w1_hw_init(dev);
dev->bus_master->data = dev;
dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;
dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;
err = w1_add_master_device(dev->bus_master);
if (err)
goto err_out_free_device;
pci_set_drvdata(pdev, dev);
dev->found = 1;
dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");
return 0;
err_out_free_device:
if (dev->virt_addr)
iounmap(dev->virt_addr);
kfree(dev);
return err;
}
static void matrox_w1_remove(struct pci_dev *pdev)
{
struct matrox_device *dev = pci_get_drvdata(pdev);
if (dev->found) {
w1_remove_master_device(dev->bus_master);
iounmap(dev->virt_addr);
}
kfree(dev);
}
static struct pci_device_id matrox_w1_tbl[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },
{ },
};
MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);
static struct pci_driver matrox_w1_pci_driver = {
.name = "matrox_w1",
.id_table = matrox_w1_tbl,
.probe = matrox_w1_probe,
.remove = matrox_w1_remove,
};
module_pci_driver(matrox_w1_pci_driver);
MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");
MODULE_LICENSE("GPL");
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