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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | // SPDX-License-Identifier: GPL-2.0-or-later /* i2c Support for Via Technologies 82C586B South Bridge Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi> */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/ioport.h> #include <linux/i2c.h> #include <linux/i2c-algo-bit.h> #include <linux/io.h> /* Power management registers */ #define PM_CFG_REVID 0x08 /* silicon revision code */ #define PM_CFG_IOBASE0 0x20 #define PM_CFG_IOBASE1 0x48 #define I2C_DIR (pm_io_base+0x40) #define I2C_OUT (pm_io_base+0x42) #define I2C_IN (pm_io_base+0x44) #define I2C_SCL 0x02 /* clock bit in DIR/OUT/IN register */ #define I2C_SDA 0x04 /* io-region reservation */ #define IOSPACE 0x06 static struct pci_driver vt586b_driver; static u16 pm_io_base; /* It does not appear from the datasheet that the GPIO pins are open drain. So a we set a low value by setting the direction to output and a high value by setting the direction to input and relying on the required I2C pullup. The data value is initialized to 0 in via_init() and never changed. */ static void bit_via_setscl(void *data, int state) { outb(state ? inb(I2C_DIR) & ~I2C_SCL : inb(I2C_DIR) | I2C_SCL, I2C_DIR); } static void bit_via_setsda(void *data, int state) { outb(state ? inb(I2C_DIR) & ~I2C_SDA : inb(I2C_DIR) | I2C_SDA, I2C_DIR); } static int bit_via_getscl(void *data) { return (0 != (inb(I2C_IN) & I2C_SCL)); } static int bit_via_getsda(void *data) { return (0 != (inb(I2C_IN) & I2C_SDA)); } static struct i2c_algo_bit_data bit_data = { .setsda = bit_via_setsda, .setscl = bit_via_setscl, .getsda = bit_via_getsda, .getscl = bit_via_getscl, .udelay = 5, .timeout = HZ }; static struct i2c_adapter vt586b_adapter = { .owner = THIS_MODULE, .class = I2C_CLASS_HWMON, .name = "VIA i2c", .algo_data = &bit_data, }; static const struct pci_device_id vt586b_ids[] = { { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_3) }, { 0, } }; MODULE_DEVICE_TABLE (pci, vt586b_ids); static int vt586b_probe(struct pci_dev *dev, const struct pci_device_id *id) { u16 base; u8 rev; int res; if (pm_io_base) { dev_err(&dev->dev, "i2c-via: Will only support one host\n"); return -ENODEV; } pci_read_config_byte(dev, PM_CFG_REVID, &rev); switch (rev) { case 0x00: base = PM_CFG_IOBASE0; break; case 0x01: case 0x10: base = PM_CFG_IOBASE1; break; default: base = PM_CFG_IOBASE1; /* later revision */ } pci_read_config_word(dev, base, &pm_io_base); pm_io_base &= (0xff << 8); if (!request_region(I2C_DIR, IOSPACE, vt586b_driver.name)) { dev_err(&dev->dev, "IO 0x%x-0x%x already in use\n", I2C_DIR, I2C_DIR + IOSPACE); return -ENODEV; } outb(inb(I2C_DIR) & ~(I2C_SDA | I2C_SCL), I2C_DIR); outb(inb(I2C_OUT) & ~(I2C_SDA | I2C_SCL), I2C_OUT); /* set up the sysfs linkage to our parent device */ vt586b_adapter.dev.parent = &dev->dev; res = i2c_bit_add_bus(&vt586b_adapter); if ( res < 0 ) { release_region(I2C_DIR, IOSPACE); pm_io_base = 0; return res; } return 0; } static void vt586b_remove(struct pci_dev *dev) { i2c_del_adapter(&vt586b_adapter); release_region(I2C_DIR, IOSPACE); pm_io_base = 0; } static struct pci_driver vt586b_driver = { .name = "vt586b_smbus", .id_table = vt586b_ids, .probe = vt586b_probe, .remove = vt586b_remove, }; module_pci_driver(vt586b_driver); MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>"); MODULE_DESCRIPTION("i2c for Via vt82c586b southbridge"); MODULE_LICENSE("GPL"); |