203 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * matrox_w1.c4 *5 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>6 */7 8#include <asm/types.h>9#include <linux/atomic.h>10#include <linux/io.h>11 12#include <linux/delay.h>13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/list.h>16#include <linux/interrupt.h>17#include <linux/spinlock.h>18#include <linux/timer.h>19#include <linux/slab.h>20#include <linux/pci_ids.h>21#include <linux/pci.h>22 23#include <linux/w1.h>24 25/*26 * Matrox G400 DDC registers.27 */28 29#define MATROX_G400_DDC_CLK (1<<4)30#define MATROX_G400_DDC_DATA (1<<1)31 32#define MATROX_BASE 0x3C0033#define MATROX_STATUS 0x1e1434 35#define MATROX_PORT_INDEX_OFFSET 0x0036#define MATROX_PORT_DATA_OFFSET 0x0A37 38#define MATROX_GET_CONTROL 0x2A39#define MATROX_GET_DATA 0x2B40#define MATROX_CURSOR_CTL 0x0641 42struct matrox_device {43 void __iomem *base_addr;44 void __iomem *port_index;45 void __iomem *port_data;46 u8 data_mask;47 48 unsigned long phys_addr;49 void __iomem *virt_addr;50 unsigned long found;51 52 struct w1_bus_master *bus_master;53};54 55/*56 * These functions read and write DDC Data bit.57 *58 * Using tristate pins, since i can't find any open-drain pin in whole motherboard.59 * Unfortunately we can't connect to Intel's 82801xx IO controller60 * since we don't know motherboard schema, which has pretty unused(may be not) GPIO.61 *62 * I've heard that PIIX also has open drain pin.63 *64 * Port mapping.65 */66static inline u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg)67{68 u8 ret;69 70 writeb(reg, dev->port_index);71 ret = readb(dev->port_data);72 barrier();73 74 return ret;75}76 77static inline void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val)78{79 writeb(reg, dev->port_index);80 writeb(val, dev->port_data);81 wmb();82}83 84static void matrox_w1_write_ddc_bit(void *data, u8 bit)85{86 u8 ret;87 struct matrox_device *dev = data;88 89 if (bit)90 bit = 0;91 else92 bit = dev->data_mask;93 94 ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL);95 matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit));96 matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00);97}98 99static u8 matrox_w1_read_ddc_bit(void *data)100{101 u8 ret;102 struct matrox_device *dev = data;103 104 ret = matrox_w1_read_reg(dev, MATROX_GET_DATA);105 106 return ret;107}108 109static void matrox_w1_hw_init(struct matrox_device *dev)110{111 matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF);112 matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00);113}114 115static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent)116{117 struct matrox_device *dev;118 int err;119 120 if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400)121 return -ENODEV;122 123 dev = kzalloc(sizeof(struct matrox_device) +124 sizeof(struct w1_bus_master), GFP_KERNEL);125 if (!dev)126 return -ENOMEM;127 128 dev->bus_master = (struct w1_bus_master *)(dev + 1);129 130 /*131 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c132 */133 134 dev->phys_addr = pci_resource_start(pdev, 1);135 136 dev->virt_addr = ioremap(dev->phys_addr, 16384);137 if (!dev->virt_addr) {138 dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n",139 __func__, dev->phys_addr, 16384);140 err = -EIO;141 goto err_out_free_device;142 }143 144 dev->base_addr = dev->virt_addr + MATROX_BASE;145 dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET;146 dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET;147 dev->data_mask = (MATROX_G400_DDC_DATA);148 149 matrox_w1_hw_init(dev);150 151 dev->bus_master->data = dev;152 dev->bus_master->read_bit = &matrox_w1_read_ddc_bit;153 dev->bus_master->write_bit = &matrox_w1_write_ddc_bit;154 155 err = w1_add_master_device(dev->bus_master);156 if (err)157 goto err_out_free_device;158 159 pci_set_drvdata(pdev, dev);160 161 dev->found = 1;162 163 dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n");164 165 return 0;166 167err_out_free_device:168 if (dev->virt_addr)169 iounmap(dev->virt_addr);170 kfree(dev);171 172 return err;173}174 175static void matrox_w1_remove(struct pci_dev *pdev)176{177 struct matrox_device *dev = pci_get_drvdata(pdev);178 179 if (dev->found) {180 w1_remove_master_device(dev->bus_master);181 iounmap(dev->virt_addr);182 }183 kfree(dev);184}185 186static struct pci_device_id matrox_w1_tbl[] = {187 { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) },188 { },189};190MODULE_DEVICE_TABLE(pci, matrox_w1_tbl);191 192static struct pci_driver matrox_w1_pci_driver = {193 .name = "matrox_w1",194 .id_table = matrox_w1_tbl,195 .probe = matrox_w1_probe,196 .remove = matrox_w1_remove,197};198module_pci_driver(matrox_w1_pci_driver);199 200MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");201MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio).");202MODULE_LICENSE("GPL");203