drivers/mfd/vx855.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Linux multi-function-device driver (MFD) for the integrated peripherals
   4  * of the VIA VX855 chipset
   5  *
   6  * Copyright (C) 2009 VIA Technologies, Inc.
   7  * Copyright (C) 2010 One Laptop per Child
   8  * Author: Harald Welte <HaraldWelte@viatech.com>
   9  * All rights reserved.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/device.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pci.h>
  17 #include <linux/mfd/core.h>
  18
  19 /* offset into pci config space indicating the 16bit register containing
  20  * the power management IO space base */
  21 #define VX855_CFG_PMIO_OFFSET   0x88
  22
  23 /* ACPI I/O Space registers */
  24 #define VX855_PMIO_ACPI         0x00
  25 #define VX855_PMIO_ACPI_LEN     0x0b
  26
  27 /* Processor Power Management */
  28 #define VX855_PMIO_PPM          0x10
  29 #define VX855_PMIO_PPM_LEN      0x08
  30
  31 /* General Purpose Power Management */
  32 #define VX855_PMIO_GPPM         0x20
  33 #define VX855_PMIO_R_GPI        0x48
  34 #define VX855_PMIO_R_GPO        0x4c
  35 #define VX855_PMIO_GPPM_LEN     0x33
  36
  37 #define VSPIC_MMIO_SIZE 0x1000
  38
  39 static struct resource vx855_gpio_resources[] = {
  40         {
  41                 .flags = IORESOURCE_IO,
  42         },
  43         {
  44                 .flags = IORESOURCE_IO,
  45         },
  46 };
  47
  48 static const struct mfd_cell vx855_cells[] = {
  49         {
  50                 .name = "vx855_gpio",
  51                 .num_resources = ARRAY_SIZE(vx855_gpio_resources),
  52                 .resources = vx855_gpio_resources,
  53
  54                 /* we must ignore resource conflicts, for reasons outlined in
  55                  * the vx855_gpio driver */
  56                 .ignore_resource_conflicts = true,
  57         },
  58 };
  59
  60 static int vx855_probe(struct pci_dev *pdev,
  61                                  const struct pci_device_id *id)
  62 {
  63         int ret;
  64         u16 gpio_io_offset;
  65
  66         ret = pci_enable_device(pdev);
  67         if (ret)
  68                 return -ENODEV;
  69
  70         pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
  71         if (!gpio_io_offset) {
  72                 dev_warn(&pdev->dev,
  73                         "BIOS did not assign PMIO base offset?!?\n");
  74                 ret = -ENODEV;
  75                 goto out;
  76         }
  77
  78         /* mask out the lowest seven bits, as they are always zero, but
  79          * hardware returns them as 0x01 */
  80         gpio_io_offset &= 0xff80;
  81
  82         /* As the region identified here includes many non-GPIO things, we
  83          * only work with the specific registers that concern us. */
  84         vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
  85         vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
  86         vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
  87         vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;
  88
  89         ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
  90                         NULL, 0, NULL);
  91
  92         /* we always return -ENODEV here in order to enable other
  93          * drivers like old, not-yet-platform_device ported i2c-viapro */
  94         return -ENODEV;
  95 out:
  96         pci_disable_device(pdev);
  97         return ret;
  98 }
  99
 100 static void vx855_remove(struct pci_dev *pdev)
 101 {
 102         mfd_remove_devices(&pdev->dev);
 103         pci_disable_device(pdev);
 104 }
 105
 106 static const struct pci_device_id vx855_pci_tbl[] = {
 107         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
 108         { 0, }
 109 };
 110 MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);
 111
 112 static struct pci_driver vx855_pci_driver = {
 113         .name           = "vx855",
 114         .id_table       = vx855_pci_tbl,
 115         .probe          = vx855_probe,
 116         .remove         = vx855_remove,
 117 };
 118
 119 module_pci_driver(vx855_pci_driver);
 120
 121 MODULE_LICENSE("GPL");
 122 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 123 MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");