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 <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 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 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 controller 60 * 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 */ 66 static 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 77 static 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 84 static 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 else 92 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 99 static 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 } 108 109 static 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 } 114 115 static 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.c 132 */ 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; 166 167 err_out_free_device: 168 if (dev->virt_addr) 169 iounmap(dev->virt_addr); 170 kfree(dev); 171 172 return err; 173 } 174 175 static 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 } 185 186 static struct pci_device_id matrox_w1_tbl[] = { 187 { PCI_DEVICE(PCI_VENDOR_ID_MATROX, PCI_DEVICE_ID_MATROX_G400) }, 188 { }, 189 }; 190 MODULE_DEVICE_TABLE(pci, matrox_w1_tbl); 191 192 static 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 }; 198 module_pci_driver(matrox_w1_pci_driver); 199 200 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); 201 MODULE_DESCRIPTION("Driver for transport(Dallas 1-wire protocol) over VGA DDC(matrox gpio)."); 202 MODULE_LICENSE("GPL"); 203