ARM: mmp: fix potential NULL dereference
[linux/fpc-iii.git] / arch / x86 / platform / scx200 / scx200_32.c
blob7a9ad30d6c9f60b47623fcd9b9e72291e7e9a8fd
1 /*
2 * Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
4 * National Semiconductor SCx200 support.
5 */
7 #include <linux/module.h>
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/mutex.h>
12 #include <linux/pci.h>
14 #include <linux/scx200.h>
15 #include <linux/scx200_gpio.h>
17 /* Verify that the configuration block really is there */
18 #define scx200_cb_probe(base) (inw((base) + SCx200_CBA) == (base))
20 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
21 MODULE_DESCRIPTION("NatSemi SCx200 Driver");
22 MODULE_LICENSE("GPL");
24 unsigned scx200_gpio_base = 0;
25 unsigned long scx200_gpio_shadow[2];
27 unsigned scx200_cb_base = 0;
29 static struct pci_device_id scx200_tbl[] = {
30 { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_BRIDGE) },
31 { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SC1100_BRIDGE) },
32 { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SCx200_XBUS) },
33 { PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_SC1100_XBUS) },
34 { },
36 MODULE_DEVICE_TABLE(pci,scx200_tbl);
38 static int __devinit scx200_probe(struct pci_dev *, const struct pci_device_id *);
40 static struct pci_driver scx200_pci_driver = {
41 .name = "scx200",
42 .id_table = scx200_tbl,
43 .probe = scx200_probe,
46 static DEFINE_MUTEX(scx200_gpio_config_lock);
48 static void __devinit scx200_init_shadow(void)
50 int bank;
52 /* read the current values driven on the GPIO signals */
53 for (bank = 0; bank < 2; ++bank)
54 scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
57 static int __devinit scx200_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
59 unsigned base;
61 if (pdev->device == PCI_DEVICE_ID_NS_SCx200_BRIDGE ||
62 pdev->device == PCI_DEVICE_ID_NS_SC1100_BRIDGE) {
63 base = pci_resource_start(pdev, 0);
64 pr_info("GPIO base 0x%x\n", base);
66 if (!request_region(base, SCx200_GPIO_SIZE,
67 "NatSemi SCx200 GPIO")) {
68 pr_err("can't allocate I/O for GPIOs\n");
69 return -EBUSY;
72 scx200_gpio_base = base;
73 scx200_init_shadow();
75 } else {
76 /* find the base of the Configuration Block */
77 if (scx200_cb_probe(SCx200_CB_BASE_FIXED)) {
78 scx200_cb_base = SCx200_CB_BASE_FIXED;
79 } else {
80 pci_read_config_dword(pdev, SCx200_CBA_SCRATCH, &base);
81 if (scx200_cb_probe(base)) {
82 scx200_cb_base = base;
83 } else {
84 pr_warn("Configuration Block not found\n");
85 return -ENODEV;
88 pr_info("Configuration Block base 0x%x\n", scx200_cb_base);
91 return 0;
94 u32 scx200_gpio_configure(unsigned index, u32 mask, u32 bits)
96 u32 config, new_config;
98 mutex_lock(&scx200_gpio_config_lock);
100 outl(index, scx200_gpio_base + 0x20);
101 config = inl(scx200_gpio_base + 0x24);
103 new_config = (config & mask) | bits;
104 outl(new_config, scx200_gpio_base + 0x24);
106 mutex_unlock(&scx200_gpio_config_lock);
108 return config;
111 static int __init scx200_init(void)
113 pr_info("NatSemi SCx200 Driver\n");
114 return pci_register_driver(&scx200_pci_driver);
117 static void __exit scx200_cleanup(void)
119 pci_unregister_driver(&scx200_pci_driver);
120 release_region(scx200_gpio_base, SCx200_GPIO_SIZE);
123 module_init(scx200_init);
124 module_exit(scx200_cleanup);
126 EXPORT_SYMBOL(scx200_gpio_base);
127 EXPORT_SYMBOL(scx200_gpio_shadow);
128 EXPORT_SYMBOL(scx200_gpio_configure);
129 EXPORT_SYMBOL(scx200_cb_base);