drivers/mfd/vx855.c

   1 /*
   2  * Linux multi-function-device driver (MFD) for the integrated peripherals
   3  * of the VIA VX855 chipset
   4  *
   5  * Copyright (C) 2009 VIA Technologies, Inc.
   6  * Copyright (C) 2010 One Laptop per Child
   7  * Author: Harald Welte <HaraldWelte@viatech.com>
   8  * All rights reserved.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  *
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/device.h>
  30 #include <linux/platform_device.h>
  31 #include <linux/pci.h>
  32 #include <linux/mfd/core.h>
  33
  34 /* offset into pci config space indicating the 16bit register containing
  35  * the power management IO space base */
  36 #define VX855_CFG_PMIO_OFFSET   0x88
  37
  38 /* ACPI I/O Space registers */
  39 #define VX855_PMIO_ACPI         0x00
  40 #define VX855_PMIO_ACPI_LEN     0x0b
  41
  42 /* Processor Power Management */
  43 #define VX855_PMIO_PPM          0x10
  44 #define VX855_PMIO_PPM_LEN      0x08
  45
  46 /* General Purpose Power Management */
  47 #define VX855_PMIO_GPPM         0x20
  48 #define VX855_PMIO_R_GPI        0x48
  49 #define VX855_PMIO_R_GPO        0x4c
  50 #define VX855_PMIO_GPPM_LEN     0x33
  51
  52 #define VSPIC_MMIO_SIZE 0x1000
  53
  54 static struct resource vx855_gpio_resources[] = {
  55         {
  56                 .flags = IORESOURCE_IO,
  57         },
  58         {
  59                 .flags = IORESOURCE_IO,
  60         },
  61 };
  62
  63 static const struct mfd_cell vx855_cells[] = {
  64         {
  65                 .name = "vx855_gpio",
  66                 .num_resources = ARRAY_SIZE(vx855_gpio_resources),
  67                 .resources = vx855_gpio_resources,
  68
  69                 /* we must ignore resource conflicts, for reasons outlined in
  70                  * the vx855_gpio driver */
  71                 .ignore_resource_conflicts = true,
  72         },
  73 };
  74
  75 static int vx855_probe(struct pci_dev *pdev,
  76                                  const struct pci_device_id *id)
  77 {
  78         int ret;
  79         u16 gpio_io_offset;
  80
  81         ret = pci_enable_device(pdev);
  82         if (ret)
  83                 return -ENODEV;
  84
  85         pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
  86         if (!gpio_io_offset) {
  87                 dev_warn(&pdev->dev,
  88                         "BIOS did not assign PMIO base offset?!?\n");
  89                 ret = -ENODEV;
  90                 goto out;
  91         }
  92
  93         /* mask out the lowest seven bits, as they are always zero, but
  94          * hardware returns them as 0x01 */
  95         gpio_io_offset &= 0xff80;
  96
  97         /* As the region identified here includes many non-GPIO things, we
  98          * only work with the specific registers that concern us. */
  99         vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
 100         vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
 101         vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
 102         vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;
 103
 104         ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
 105                         NULL, 0, NULL);
 106
 107         /* we always return -ENODEV here in order to enable other
 108          * drivers like old, not-yet-platform_device ported i2c-viapro */
 109         return -ENODEV;
 110 out:
 111         pci_disable_device(pdev);
 112         return ret;
 113 }
 114
 115 static void vx855_remove(struct pci_dev *pdev)
 116 {
 117         mfd_remove_devices(&pdev->dev);
 118         pci_disable_device(pdev);
 119 }
 120
 121 static const struct pci_device_id vx855_pci_tbl[] = {
 122         { PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
 123         { 0, }
 124 };
 125 MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);
 126
 127 static struct pci_driver vx855_pci_driver = {
 128         .name           = "vx855",
 129         .id_table       = vx855_pci_tbl,
 130         .probe          = vx855_probe,
 131         .remove         = vx855_remove,
 132 };
 133
 134 module_pci_driver(vx855_pci_driver);
 135
 136 MODULE_LICENSE("GPL");
 137 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
 138 MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");