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e329113c BG |
1 | /* |
2 | * AMD CS5535/CS5536 GPIO driver. | |
3 | * Allows a user space process to play with the GPIO pins. | |
4 | * | |
5 | * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the smems of the GNU General Public License as published by | |
9 | * the Free Software Foundation; version 2 of the License. | |
10 | */ | |
11 | ||
12 | #include <linux/fs.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/errno.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/cdev.h> | |
18 | #include <linux/ioport.h> | |
19 | #include <linux/pci.h> | |
20 | #include <asm/uaccess.h> | |
21 | #include <asm/io.h> | |
22 | ||
23 | ||
24 | #define NAME "cs5535_gpio" | |
25 | ||
26 | MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); | |
27 | MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO Pin Driver"); | |
28 | MODULE_LICENSE("GPL"); | |
29 | ||
30 | static int major; | |
31 | module_param(major, int, 0); | |
32 | MODULE_PARM_DESC(major, "Major device number"); | |
33 | ||
34 | static ulong mask; | |
35 | module_param(mask, ulong, 0); | |
36 | MODULE_PARM_DESC(mask, "GPIO channel mask"); | |
37 | ||
38 | #define MSR_LBAR_GPIO 0x5140000C | |
39 | ||
40 | static u32 gpio_base; | |
41 | ||
42 | static struct pci_device_id divil_pci[] = { | |
43 | { PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) }, | |
44 | { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) }, | |
45 | { } /* NULL entry */ | |
46 | }; | |
524e6752 | 47 | MODULE_DEVICE_TABLE(pci, divil_pci); |
e329113c BG |
48 | |
49 | static struct cdev cs5535_gpio_cdev; | |
50 | ||
51 | /* reserve 32 entries even though some aren't usable */ | |
52 | #define CS5535_GPIO_COUNT 32 | |
53 | ||
54 | /* IO block size */ | |
55 | #define CS5535_GPIO_SIZE 256 | |
56 | ||
57 | struct gpio_regmap { | |
58 | u32 rd_offset; | |
59 | u32 wr_offset; | |
60 | char on; | |
61 | char off; | |
62 | }; | |
63 | static struct gpio_regmap rm[] = | |
64 | { | |
65 | { 0x30, 0x00, '1', '0' }, /* GPIOx_READ_BACK / GPIOx_OUT_VAL */ | |
66 | { 0x20, 0x20, 'I', 'i' }, /* GPIOx_IN_EN */ | |
67 | { 0x04, 0x04, 'O', 'o' }, /* GPIOx_OUT_EN */ | |
68 | { 0x08, 0x08, 't', 'T' }, /* GPIOx_OUT_OD_EN */ | |
69 | { 0x18, 0x18, 'P', 'p' }, /* GPIOx_OUT_PU_EN */ | |
70 | { 0x1c, 0x1c, 'D', 'd' }, /* GPIOx_OUT_PD_EN */ | |
71 | }; | |
72 | ||
73 | ||
74 | /** | |
75 | * Gets the register offset for the GPIO bank. | |
76 | * Low (0-15) starts at 0x00, high (16-31) starts at 0x80 | |
77 | */ | |
78 | static inline u32 cs5535_lowhigh_base(int reg) | |
79 | { | |
80 | return (reg & 0x10) << 3; | |
81 | } | |
82 | ||
83 | static ssize_t cs5535_gpio_write(struct file *file, const char __user *data, | |
84 | size_t len, loff_t *ppos) | |
85 | { | |
a7113a96 | 86 | u32 m = iminor(file->f_path.dentry->d_inode); |
e329113c BG |
87 | int i, j; |
88 | u32 base = gpio_base + cs5535_lowhigh_base(m); | |
89 | u32 m0, m1; | |
90 | char c; | |
91 | ||
92 | /** | |
93 | * Creates the mask for atomic bit programming. | |
94 | * The high 16 bits and the low 16 bits are used to set the mask. | |
95 | * For example, GPIO 15 maps to 31,15: 0,1 => On; 1,0=> Off | |
96 | */ | |
97 | m1 = 1 << (m & 0x0F); | |
98 | m0 = m1 << 16; | |
99 | ||
100 | for (i = 0; i < len; ++i) { | |
101 | if (get_user(c, data+i)) | |
102 | return -EFAULT; | |
103 | ||
104 | for (j = 0; j < ARRAY_SIZE(rm); j++) { | |
105 | if (c == rm[j].on) { | |
106 | outl(m1, base + rm[j].wr_offset); | |
4670df83 BG |
107 | /* If enabling output, turn off AUX 1 and AUX 2 */ |
108 | if (c == 'O') { | |
109 | outl(m0, base + 0x10); | |
110 | outl(m0, base + 0x14); | |
111 | } | |
e329113c BG |
112 | break; |
113 | } else if (c == rm[j].off) { | |
114 | outl(m0, base + rm[j].wr_offset); | |
115 | break; | |
116 | } | |
117 | } | |
118 | } | |
119 | *ppos = 0; | |
120 | return len; | |
121 | } | |
122 | ||
123 | static ssize_t cs5535_gpio_read(struct file *file, char __user *buf, | |
124 | size_t len, loff_t *ppos) | |
125 | { | |
a7113a96 | 126 | u32 m = iminor(file->f_path.dentry->d_inode); |
e329113c BG |
127 | u32 base = gpio_base + cs5535_lowhigh_base(m); |
128 | int rd_bit = 1 << (m & 0x0f); | |
129 | int i; | |
130 | char ch; | |
131 | ssize_t count = 0; | |
132 | ||
133 | if (*ppos >= ARRAY_SIZE(rm)) | |
134 | return 0; | |
135 | ||
136 | for (i = *ppos; (i < (*ppos + len)) && (i < ARRAY_SIZE(rm)); i++) { | |
137 | ch = (inl(base + rm[i].rd_offset) & rd_bit) ? | |
138 | rm[i].on : rm[i].off; | |
139 | ||
140 | if (put_user(ch, buf+count)) | |
141 | return -EFAULT; | |
142 | ||
143 | count++; | |
144 | } | |
145 | ||
146 | /* add a line-feed if there is room */ | |
147 | if ((i == ARRAY_SIZE(rm)) && (count < len)) { | |
148 | put_user('\n', buf + count); | |
149 | count++; | |
150 | } | |
151 | ||
152 | *ppos += count; | |
153 | return count; | |
154 | } | |
155 | ||
d21c95c5 JC |
156 | /* No BKL needed here - "mask" is the only global resource used |
157 | here and it's a boot-time parameter */ | |
e329113c BG |
158 | static int cs5535_gpio_open(struct inode *inode, struct file *file) |
159 | { | |
160 | u32 m = iminor(inode); | |
161 | ||
162 | /* the mask says which pins are usable by this driver */ | |
163 | if ((mask & (1 << m)) == 0) | |
164 | return -EINVAL; | |
165 | ||
166 | return nonseekable_open(inode, file); | |
167 | } | |
168 | ||
62322d25 | 169 | static const struct file_operations cs5535_gpio_fops = { |
e329113c BG |
170 | .owner = THIS_MODULE, |
171 | .write = cs5535_gpio_write, | |
172 | .read = cs5535_gpio_read, | |
173 | .open = cs5535_gpio_open | |
174 | }; | |
175 | ||
176 | static int __init cs5535_gpio_init(void) | |
177 | { | |
178 | dev_t dev_id; | |
179 | u32 low, hi; | |
180 | int retval; | |
181 | ||
182 | if (pci_dev_present(divil_pci) == 0) { | |
183 | printk(KERN_WARNING NAME ": DIVIL not found\n"); | |
184 | return -ENODEV; | |
185 | } | |
186 | ||
187 | /* Grab the GPIO I/O range */ | |
188 | rdmsr(MSR_LBAR_GPIO, low, hi); | |
189 | ||
190 | /* Check the mask and whether GPIO is enabled (sanity check) */ | |
191 | if (hi != 0x0000f001) { | |
192 | printk(KERN_WARNING NAME ": GPIO not enabled\n"); | |
193 | return -ENODEV; | |
194 | } | |
195 | ||
196 | /* Mask off the IO base address */ | |
197 | gpio_base = low & 0x0000ff00; | |
198 | ||
199 | /** | |
200 | * Some GPIO pins | |
201 | * 31-29,23 : reserved (always mask out) | |
202 | * 28 : Power Button | |
203 | * 26 : PME# | |
204 | * 22-16 : LPC | |
205 | * 14,15 : SMBus | |
206 | * 9,8 : UART1 | |
207 | * 7 : PCI INTB | |
208 | * 3,4 : UART2/DDC | |
209 | * 2 : IDE_IRQ0 | |
210 | * 0 : PCI INTA | |
211 | * | |
212 | * If a mask was not specified, be conservative and only allow: | |
213 | * 1,2,5,6,10-13,24,25,27 | |
214 | */ | |
215 | if (mask != 0) | |
216 | mask &= 0x1f7fffff; | |
217 | else | |
218 | mask = 0x0b003c66; | |
219 | ||
a01e035e | 220 | if (!request_region(gpio_base, CS5535_GPIO_SIZE, NAME)) { |
e329113c BG |
221 | printk(KERN_ERR NAME ": can't allocate I/O for GPIO\n"); |
222 | return -ENODEV; | |
223 | } | |
224 | ||
225 | if (major) { | |
226 | dev_id = MKDEV(major, 0); | |
227 | retval = register_chrdev_region(dev_id, CS5535_GPIO_COUNT, | |
228 | NAME); | |
229 | } else { | |
230 | retval = alloc_chrdev_region(&dev_id, 0, CS5535_GPIO_COUNT, | |
231 | NAME); | |
232 | major = MAJOR(dev_id); | |
233 | } | |
234 | ||
235 | if (retval) { | |
236 | release_region(gpio_base, CS5535_GPIO_SIZE); | |
237 | return -1; | |
238 | } | |
239 | ||
240 | printk(KERN_DEBUG NAME ": base=%#x mask=%#lx major=%d\n", | |
241 | gpio_base, mask, major); | |
242 | ||
243 | cdev_init(&cs5535_gpio_cdev, &cs5535_gpio_fops); | |
244 | cdev_add(&cs5535_gpio_cdev, dev_id, CS5535_GPIO_COUNT); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | static void __exit cs5535_gpio_cleanup(void) | |
250 | { | |
251 | dev_t dev_id = MKDEV(major, 0); | |
03246800 TS |
252 | |
253 | cdev_del(&cs5535_gpio_cdev); | |
e329113c | 254 | unregister_chrdev_region(dev_id, CS5535_GPIO_COUNT); |
03246800 | 255 | release_region(gpio_base, CS5535_GPIO_SIZE); |
e329113c BG |
256 | } |
257 | ||
258 | module_init(cs5535_gpio_init); | |
259 | module_exit(cs5535_gpio_cleanup); |