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