LXR linux/arch/x86/platform/scx200/scx200

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
   4 *
   5 *  National Semiconductor SCx200 support.
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/errno.h>
  10#include <linux/kernel.h>
  11#include <linux/init.h>
  12#include <linux/mutex.h>
  13#include <linux/pci.h>
  14
  15#include <linux/scx200.h>
  16#include <linux/scx200_gpio.h>
  17
  18/* Verify that the configuration block really is there */
  19#define scx200_cb_probe(base) (inw((base) + SCx200_CBA) == (base))
  20
  21MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
  22MODULE_DESCRIPTION("NatSemi SCx200 Driver");
  23MODULE_LICENSE("GPL");
  24
  25unsigned scx200_gpio_base = 0;
  26unsigned long scx200_gpio_shadow[2];
  27
  28unsigned scx200_cb_base = 0;
  29
  30static struct pci_device_id scx200_tbl[] = {
  31        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
  32        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
  33        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_XBUS)   },
  34        { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SC1100_XBUS)   },
  35        { },
  36};
  37MODULE_DEVICE_TABLE(pci,scx200_tbl);
  38
  39static int scx200_probe(struct pci_dev *, const struct pci_device_id *);
  40
  41static struct pci_driver scx200_pci_driver = {
  42        .name = "scx200",
  43        .id_table = scx200_tbl,
  44        .probe = scx200_probe,
  45};
  46
  47static DEFINE_MUTEX(scx200_gpio_config_lock);
  48
  49static void scx200_init_shadow(void)
  50{
  51        int bank;
  52
  53        /* read the current values driven on the GPIO signals */
  54        for (bank = 0; bank < 2; ++bank)
  55                scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
  56}
  57
  58static int scx200_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
  59{
  60        unsigned base;
  61
  62        if (pdev->device == PCI_DEVICE_ID_NS_SCx200_BRIDGE ||
  63            pdev->device == PCI_DEVICE_ID_NS_SC1100_BRIDGE) {
  64                base = pci_resource_start(pdev, 0);
  65                pr_info("GPIO base 0x%x\n", base);
  66
  67                if (!request_region(base, SCx200_GPIO_SIZE,
  68                                    "NatSemi SCx200 GPIO")) {
  69                        pr_err("can't allocate I/O for GPIOs\n");
  70                        return -EBUSY;
  71                }
  72
  73                scx200_gpio_base = base;
  74                scx200_init_shadow();
  75
  76        } else {
  77                /* find the base of the Configuration Block */
  78                if (scx200_cb_probe(SCx200_CB_BASE_FIXED)) {
  79                        scx200_cb_base = SCx200_CB_BASE_FIXED;
  80                } else {
  81                        pci_read_config_dword(pdev, SCx200_CBA_SCRATCH, &base);
  82                        if (scx200_cb_probe(base)) {
  83                                scx200_cb_base = base;
  84                        } else {
  85                                pr_warn("Configuration Block not found\n");
  86                                return -ENODEV;
  87                        }
  88                }
  89                pr_info("Configuration Block base 0x%x\n", scx200_cb_base);
  90        }
  91
  92        return 0;
  93}
  94
  95u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
  96{
  97        u32 config, new_config;
  98
  99        mutex_lock(&scx200_gpio_config_lock);
 100
 101        outl(index, scx200_gpio_base + 0x20);
 102        config = inl(scx200_gpio_base + 0x24);
 103
 104        new_config = (config & mask) | bits;
 105        outl(new_config, scx200_gpio_base + 0x24);
 106
 107        mutex_unlock(&scx200_gpio_config_lock);
 108
 109        return config;
 110}
 111
 112static int __init scx200_init(void)
 113{
 114        pr_info("NatSemi SCx200 Driver\n");
 115        return pci_register_driver(&scx200_pci_driver);
 116}
 117
 118static void __exit scx200_cleanup(void)
 119{
 120        pci_unregister_driver(&scx200_pci_driver);
 121        release_region(scx200_gpio_base, SCx200_GPIO_SIZE);
 122}
 123
 124module_init(scx200_init);
 125module_exit(scx200_cleanup);
 126
 127EXPORT_SYMBOL(scx200_gpio_base);
 128EXPORT_SYMBOL(scx200_gpio_shadow);
 129EXPORT_SYMBOL(scx200_gpio_configure);
 130EXPORT_SYMBOL(scx200_cb_base);
 131