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1 | /* |
2 | * Copyright 2017 IBM Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <linux/mfd/syscon.h> | |
11 | #include <linux/miscdevice.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/of_address.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/poll.h> | |
17 | #include <linux/regmap.h> | |
18 | ||
19 | #include <linux/aspeed-lpc-ctrl.h> | |
20 | ||
21 | #define DEVICE_NAME "aspeed-lpc-ctrl" | |
22 | ||
23 | #define HICR7 0x8 | |
24 | #define HICR8 0xc | |
25 | ||
26 | struct aspeed_lpc_ctrl { | |
27 | struct miscdevice miscdev; | |
28 | struct regmap *regmap; | |
29 | phys_addr_t mem_base; | |
30 | resource_size_t mem_size; | |
31 | u32 pnor_size; | |
32 | u32 pnor_base; | |
33 | }; | |
34 | ||
35 | static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) | |
36 | { | |
37 | return container_of(file->private_data, struct aspeed_lpc_ctrl, | |
38 | miscdev); | |
39 | } | |
40 | ||
41 | static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) | |
42 | { | |
43 | struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); | |
44 | unsigned long vsize = vma->vm_end - vma->vm_start; | |
45 | pgprot_t prot = vma->vm_page_prot; | |
46 | ||
47 | if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) | |
48 | return -EINVAL; | |
49 | ||
50 | /* ast2400/2500 AHB accesses are not cache coherent */ | |
132c93d4 | 51 | prot = pgprot_noncached(prot); |
6c4e9767 CB |
52 | |
53 | if (remap_pfn_range(vma, vma->vm_start, | |
54 | (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, | |
55 | vsize, prot)) | |
56 | return -EAGAIN; | |
57 | ||
58 | return 0; | |
59 | } | |
60 | ||
61 | static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, | |
62 | unsigned long param) | |
63 | { | |
64 | struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); | |
65 | void __user *p = (void __user *)param; | |
66 | struct aspeed_lpc_ctrl_mapping map; | |
67 | u32 addr; | |
68 | u32 size; | |
69 | long rc; | |
70 | ||
71 | if (copy_from_user(&map, p, sizeof(map))) | |
72 | return -EFAULT; | |
73 | ||
74 | if (map.flags != 0) | |
75 | return -EINVAL; | |
76 | ||
77 | switch (cmd) { | |
78 | case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: | |
79 | /* The flash windows don't report their size */ | |
80 | if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) | |
81 | return -EINVAL; | |
82 | ||
83 | /* Support more than one window id in the future */ | |
84 | if (map.window_id != 0) | |
85 | return -EINVAL; | |
86 | ||
87 | map.size = lpc_ctrl->mem_size; | |
88 | ||
89 | return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; | |
90 | case ASPEED_LPC_CTRL_IOCTL_MAP: | |
91 | ||
92 | /* | |
93 | * The top half of HICR7 is the MSB of the BMC address of the | |
94 | * mapping. | |
95 | * The bottom half of HICR7 is the MSB of the HOST LPC | |
96 | * firmware space address of the mapping. | |
97 | * | |
98 | * The 1 bits in the top of half of HICR8 represent the bits | |
99 | * (in the requested address) that should be ignored and | |
100 | * replaced with those from the top half of HICR7. | |
101 | * The 1 bits in the bottom half of HICR8 represent the bits | |
102 | * (in the requested address) that should be kept and pass | |
103 | * into the BMC address space. | |
104 | */ | |
105 | ||
106 | /* | |
107 | * It doesn't make sense to talk about a size or offset with | |
108 | * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 | |
109 | * bits of addresses and sizes. | |
110 | */ | |
111 | ||
112 | if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) | |
113 | return -EINVAL; | |
114 | ||
115 | /* | |
116 | * Because of the way the masks work in HICR8 offset has to | |
117 | * be a multiple of size. | |
118 | */ | |
119 | if (map.offset & (map.size - 1)) | |
120 | return -EINVAL; | |
121 | ||
122 | if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { | |
123 | addr = lpc_ctrl->pnor_base; | |
124 | size = lpc_ctrl->pnor_size; | |
125 | } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { | |
126 | addr = lpc_ctrl->mem_base; | |
127 | size = lpc_ctrl->mem_size; | |
128 | } else { | |
129 | return -EINVAL; | |
130 | } | |
131 | ||
132 | /* Check overflow first! */ | |
133 | if (map.offset + map.size < map.offset || | |
134 | map.offset + map.size > size) | |
135 | return -EINVAL; | |
136 | ||
137 | if (map.size == 0 || map.size > size) | |
138 | return -EINVAL; | |
139 | ||
140 | addr += map.offset; | |
141 | ||
142 | /* | |
143 | * addr (host lpc address) is safe regardless of values. This | |
144 | * simply changes the address the host has to request on its | |
145 | * side of the LPC bus. This cannot impact the hosts own | |
146 | * memory space by surprise as LPC specific accessors are | |
147 | * required. The only strange thing that could be done is | |
148 | * setting the lower 16 bits but the shift takes care of that. | |
149 | */ | |
150 | ||
151 | rc = regmap_write(lpc_ctrl->regmap, HICR7, | |
152 | (addr | (map.addr >> 16))); | |
153 | if (rc) | |
154 | return rc; | |
155 | ||
156 | return regmap_write(lpc_ctrl->regmap, HICR8, | |
157 | (~(map.size - 1)) | ((map.size >> 16) - 1)); | |
158 | } | |
159 | ||
160 | return -EINVAL; | |
161 | } | |
162 | ||
163 | static const struct file_operations aspeed_lpc_ctrl_fops = { | |
164 | .owner = THIS_MODULE, | |
165 | .mmap = aspeed_lpc_ctrl_mmap, | |
166 | .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, | |
167 | }; | |
168 | ||
169 | static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) | |
170 | { | |
171 | struct aspeed_lpc_ctrl *lpc_ctrl; | |
172 | struct device_node *node; | |
173 | struct resource resm; | |
174 | struct device *dev; | |
175 | int rc; | |
176 | ||
177 | dev = &pdev->dev; | |
178 | ||
179 | lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); | |
180 | if (!lpc_ctrl) | |
181 | return -ENOMEM; | |
182 | ||
183 | node = of_parse_phandle(dev->of_node, "flash", 0); | |
184 | if (!node) { | |
185 | dev_err(dev, "Didn't find host pnor flash node\n"); | |
186 | return -ENODEV; | |
187 | } | |
188 | ||
189 | rc = of_address_to_resource(node, 1, &resm); | |
190 | of_node_put(node); | |
191 | if (rc) { | |
192 | dev_err(dev, "Couldn't address to resource for flash\n"); | |
193 | return rc; | |
194 | } | |
195 | ||
196 | lpc_ctrl->pnor_size = resource_size(&resm); | |
197 | lpc_ctrl->pnor_base = resm.start; | |
198 | ||
199 | dev_set_drvdata(&pdev->dev, lpc_ctrl); | |
200 | ||
201 | node = of_parse_phandle(dev->of_node, "memory-region", 0); | |
202 | if (!node) { | |
203 | dev_err(dev, "Didn't find reserved memory\n"); | |
204 | return -EINVAL; | |
205 | } | |
206 | ||
207 | rc = of_address_to_resource(node, 0, &resm); | |
208 | of_node_put(node); | |
209 | if (rc) { | |
210 | dev_err(dev, "Couldn't address to resource for reserved memory\n"); | |
211 | return -ENOMEM; | |
212 | } | |
213 | ||
214 | lpc_ctrl->mem_size = resource_size(&resm); | |
215 | lpc_ctrl->mem_base = resm.start; | |
216 | ||
217 | lpc_ctrl->regmap = syscon_node_to_regmap( | |
218 | pdev->dev.parent->of_node); | |
219 | if (IS_ERR(lpc_ctrl->regmap)) { | |
220 | dev_err(dev, "Couldn't get regmap\n"); | |
221 | return -ENODEV; | |
222 | } | |
223 | ||
224 | lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; | |
225 | lpc_ctrl->miscdev.name = DEVICE_NAME; | |
226 | lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; | |
227 | lpc_ctrl->miscdev.parent = dev; | |
228 | rc = misc_register(&lpc_ctrl->miscdev); | |
229 | if (rc) | |
230 | dev_err(dev, "Unable to register device\n"); | |
231 | else | |
8ff0c566 | 232 | dev_info(dev, "Loaded at %pr\n", &resm); |
6c4e9767 CB |
233 | |
234 | return rc; | |
235 | } | |
236 | ||
237 | static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) | |
238 | { | |
239 | struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); | |
240 | ||
241 | misc_deregister(&lpc_ctrl->miscdev); | |
242 | ||
243 | return 0; | |
244 | } | |
245 | ||
246 | static const struct of_device_id aspeed_lpc_ctrl_match[] = { | |
247 | { .compatible = "aspeed,ast2400-lpc-ctrl" }, | |
248 | { .compatible = "aspeed,ast2500-lpc-ctrl" }, | |
249 | { }, | |
250 | }; | |
251 | ||
252 | static struct platform_driver aspeed_lpc_ctrl_driver = { | |
253 | .driver = { | |
254 | .name = DEVICE_NAME, | |
255 | .of_match_table = aspeed_lpc_ctrl_match, | |
256 | }, | |
257 | .probe = aspeed_lpc_ctrl_probe, | |
258 | .remove = aspeed_lpc_ctrl_remove, | |
259 | }; | |
260 | ||
261 | module_platform_driver(aspeed_lpc_ctrl_driver); | |
262 | ||
263 | MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); | |
264 | MODULE_LICENSE("GPL"); | |
265 | MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); | |
266 | MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings"); |