1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * matrox_w1.c 4 * 5 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> 6 */ 7 8 #include <asm/types.h> 9 #include <linux/atomic.h> 10 #include <asm/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 0x3C00 33 #define MATROX_STATUS 0x1e14 34 35 #define MATROX_PORT_INDEX_OFFSET 0x00 36 #define MATROX_PORT_DATA_OFFSET 0x0A 37 38 #define MATROX_GET_CONTROL 0x2A 39 #define MATROX_GET_DATA 0x2B 40 #define MATROX_CURSOR_CTL 0x06 41 42 struct matrox_device 43 { 44 void __iomem *base_addr; 45 void __iomem *port_index; 46 void __iomem *port_data; 47 u8 data_mask; 48 49 unsigned long phys_addr; 50 void __iomem *virt_addr; 51 unsigned long found; 52 53 struct w1_bus_master *bus_master; 54 }; 55 56 /* 57 * These functions read and write DDC Data bit. 58 * 59 * Using tristate pins, since i can't find any open-drain pin in whole motherboard. 60 * Unfortunately we can't connect to Intel's 82801xx IO controller 61 * since we don't know motherboard schema, which has pretty unused(may be not) GPIO. 62 * 63 * I've heard that PIIX also has open drain pin. 64 * 65 * Port mapping. 66 */ 67 static __inline__ u8 matrox_w1_read_reg(struct matrox_device *dev, u8 reg) 68 { 69 u8 ret; 70 71 writeb(reg, dev->port_index); 72 ret = readb(dev->port_data); 73 barrier(); 74 75 return ret; 76 } 77 78 static __inline__ void matrox_w1_write_reg(struct matrox_device *dev, u8 reg, u8 val) 79 { 80 writeb(reg, dev->port_index); 81 writeb(val, dev->port_data); 82 wmb(); 83 } 84 85 static void matrox_w1_write_ddc_bit(void *data, u8 bit) 86 { 87 u8 ret; 88 struct matrox_device *dev = data; 89 90 if (bit) 91 bit = 0; 92 else 93 bit = dev->data_mask; 94 95 ret = matrox_w1_read_reg(dev, MATROX_GET_CONTROL); 96 matrox_w1_write_reg(dev, MATROX_GET_CONTROL, ((ret & ~dev->data_mask) | bit)); 97 matrox_w1_write_reg(dev, MATROX_GET_DATA, 0x00); 98 } 99 100 static u8 matrox_w1_read_ddc_bit(void *data) 101 { 102 u8 ret; 103 struct matrox_device *dev = data; 104 105 ret = matrox_w1_read_reg(dev, MATROX_GET_DATA); 106 107 return ret; 108 } 109 110 static void matrox_w1_hw_init(struct matrox_device *dev) 111 { 112 matrox_w1_write_reg(dev, MATROX_GET_DATA, 0xFF); 113 matrox_w1_write_reg(dev, MATROX_GET_CONTROL, 0x00); 114 } 115 116 static int matrox_w1_probe(struct pci_dev *pdev, const struct pci_device_id *ent) 117 { 118 struct matrox_device *dev; 119 int err; 120 121 if (pdev->vendor != PCI_VENDOR_ID_MATROX || pdev->device != PCI_DEVICE_ID_MATROX_G400) 122 return -ENODEV; 123 124 dev = kzalloc(sizeof(struct matrox_device) + 125 sizeof(struct w1_bus_master), GFP_KERNEL); 126 if (!dev) { 127 dev_err(&pdev->dev, 128 "%s: Failed to create new matrox_device object.\n", 129 __func__); 130 return -ENOMEM; 131 } 132 133 134 dev->bus_master = (struct w1_bus_master *)(dev + 1); 135 136 /* 137 * True for G400, for some other we need resource 0, see drivers/video/matrox/matroxfb_base.c 138 */ 139 140 dev->phys_addr = pci_resource_start(pdev, 1); 141 142 dev->virt_addr = ioremap_nocache(dev->phys_addr, 16384); 143 if (!dev->virt_addr) { 144 dev_err(&pdev->dev, "%s: failed to ioremap(0x%lx, %d).\n", 145 __func__, dev->phys_addr, 16384); 146 err = -EIO; 147 goto err_out_free_device; 148 } 149 150 dev->base_addr = dev->virt_addr + MATROX_BASE; 151 dev->port_index = dev->base_addr + MATROX_PORT_INDEX_OFFSET; 152 dev->port_data = dev->base_addr + MATROX_PORT_DATA_OFFSET; 153 dev->data_mask = (MATROX_G400_DDC_DATA); 154 155 matrox_w1_hw_init(dev); 156 157 dev->bus_master->data = dev; 158 dev->bus_master->read_bit = &matrox_w1_read_ddc_bit; 159 dev->bus_master->write_bit = &matrox_w1_write_ddc_bit; 160 161 err = w1_add_master_device(dev->bus_master); 162 if (err) 163 goto err_out_free_device; 164 165 pci_set_drvdata(pdev, dev); 166 167 dev->found = 1; 168 169 dev_info(&pdev->dev, "Matrox G400 GPIO transport layer for 1-wire.\n"); 170 171 return 0; 172 173 err_out_free_device: 174 if (dev->virt_addr) 175 iounmap(dev->virt_addr); 176 kfree(dev); 177 178 return err; 179 } 180 181 static void matrox_w1_remove(struct pci_dev *pdev) 182 { 183 struct matrox_device *dev = pci_get_drvdata(pdev); 184 185 if (dev->found) { 186 w1_remove_master_device(dev->bus_master); 187 iounmap(dev->virt_addr); 188 } 189 kfree(dev); 190 } 191 192 static struct pci_device_id matrox_w1_tbl[] = { 193 { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) }, 194 { }, 195 }; 196 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl); 197 198 static struct pci_driver matrox_w1_pci_driver = { 199 .name = "matrox_w1", 200 .id_table = matrox_w1_tbl, 201 .probe = matrox_w1_probe, 202 .remove = matrox_w1_remove, 203 }; 204 module_pci_driver(matrox_w1_pci_driver); 205 206 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 207 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio)."); 208 MODULE_LICENSE("GPL"); 209