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1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License version 2 as | |
4 | * published by the Free Software Foundation. | |
5 | * | |
6 | * This program is distributed in the hope that it will be useful, | |
7 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
8 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
9 | * GNU General Public License for more details. | |
10 | * | |
11 | * Copyright (C) 2014 ARM Limited | |
12 | */ | |
13 | ||
14 | #include <linux/delay.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/io.h> | |
17 | #include <linux/of.h> | |
18 | #include <linux/platform_device.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/syscore_ops.h> | |
22 | #include <linux/vexpress.h> | |
23 | ||
24 | ||
25 | #define SYS_CFGDATA 0x0 | |
26 | ||
27 | #define SYS_CFGCTRL 0x4 | |
28 | #define SYS_CFGCTRL_START (1 << 31) | |
29 | #define SYS_CFGCTRL_WRITE (1 << 30) | |
30 | #define SYS_CFGCTRL_DCC(n) (((n) & 0xf) << 26) | |
31 | #define SYS_CFGCTRL_FUNC(n) (((n) & 0x3f) << 20) | |
32 | #define SYS_CFGCTRL_SITE(n) (((n) & 0x3) << 16) | |
33 | #define SYS_CFGCTRL_POSITION(n) (((n) & 0xf) << 12) | |
34 | #define SYS_CFGCTRL_DEVICE(n) (((n) & 0xfff) << 0) | |
35 | ||
36 | #define SYS_CFGSTAT 0x8 | |
37 | #define SYS_CFGSTAT_ERR (1 << 1) | |
38 | #define SYS_CFGSTAT_COMPLETE (1 << 0) | |
39 | ||
40 | ||
41 | struct vexpress_syscfg { | |
42 | struct device *dev; | |
43 | void __iomem *base; | |
44 | struct list_head funcs; | |
45 | }; | |
46 | ||
47 | struct vexpress_syscfg_func { | |
48 | struct list_head list; | |
49 | struct vexpress_syscfg *syscfg; | |
50 | struct regmap *regmap; | |
51 | int num_templates; | |
52 | u32 template[0]; /* Keep it last! */ | |
53 | }; | |
54 | ||
55 | ||
56 | static int vexpress_syscfg_exec(struct vexpress_syscfg_func *func, | |
57 | int index, bool write, u32 *data) | |
58 | { | |
59 | struct vexpress_syscfg *syscfg = func->syscfg; | |
60 | u32 command, status; | |
61 | int tries; | |
62 | long timeout; | |
63 | ||
64 | if (WARN_ON(index > func->num_templates)) | |
65 | return -EINVAL; | |
66 | ||
67 | command = readl(syscfg->base + SYS_CFGCTRL); | |
68 | if (WARN_ON(command & SYS_CFGCTRL_START)) | |
69 | return -EBUSY; | |
70 | ||
71 | command = func->template[index]; | |
72 | command |= SYS_CFGCTRL_START; | |
73 | command |= write ? SYS_CFGCTRL_WRITE : 0; | |
74 | ||
75 | /* Use a canary for reads */ | |
76 | if (!write) | |
77 | *data = 0xdeadbeef; | |
78 | ||
79 | dev_dbg(syscfg->dev, "func %p, command %x, data %x\n", | |
80 | func, command, *data); | |
81 | writel(*data, syscfg->base + SYS_CFGDATA); | |
82 | writel(0, syscfg->base + SYS_CFGSTAT); | |
83 | writel(command, syscfg->base + SYS_CFGCTRL); | |
84 | mb(); | |
85 | ||
86 | /* The operation can take ages... Go to sleep, 100us initially */ | |
87 | tries = 100; | |
88 | timeout = 100; | |
89 | do { | |
90 | if (!irqs_disabled()) { | |
91 | set_current_state(TASK_INTERRUPTIBLE); | |
92 | schedule_timeout(usecs_to_jiffies(timeout)); | |
93 | if (signal_pending(current)) | |
94 | return -EINTR; | |
95 | } else { | |
96 | udelay(timeout); | |
97 | } | |
98 | ||
99 | status = readl(syscfg->base + SYS_CFGSTAT); | |
100 | if (status & SYS_CFGSTAT_ERR) | |
101 | return -EFAULT; | |
102 | ||
103 | if (timeout > 20) | |
104 | timeout -= 20; | |
105 | } while (--tries && !(status & SYS_CFGSTAT_COMPLETE)); | |
106 | if (WARN_ON_ONCE(!tries)) | |
107 | return -ETIMEDOUT; | |
108 | ||
109 | if (!write) { | |
110 | *data = readl(syscfg->base + SYS_CFGDATA); | |
111 | dev_dbg(syscfg->dev, "func %p, read data %x\n", func, *data); | |
112 | } | |
113 | ||
114 | return 0; | |
115 | } | |
116 | ||
117 | static int vexpress_syscfg_read(void *context, unsigned int index, | |
118 | unsigned int *val) | |
119 | { | |
120 | struct vexpress_syscfg_func *func = context; | |
121 | ||
122 | return vexpress_syscfg_exec(func, index, false, val); | |
123 | } | |
124 | ||
125 | static int vexpress_syscfg_write(void *context, unsigned int index, | |
126 | unsigned int val) | |
127 | { | |
128 | struct vexpress_syscfg_func *func = context; | |
129 | ||
130 | return vexpress_syscfg_exec(func, index, true, &val); | |
131 | } | |
132 | ||
133 | struct regmap_config vexpress_syscfg_regmap_config = { | |
134 | .lock = vexpress_config_lock, | |
135 | .unlock = vexpress_config_unlock, | |
136 | .reg_bits = 32, | |
137 | .val_bits = 32, | |
138 | .reg_read = vexpress_syscfg_read, | |
139 | .reg_write = vexpress_syscfg_write, | |
140 | .reg_format_endian = REGMAP_ENDIAN_LITTLE, | |
141 | .val_format_endian = REGMAP_ENDIAN_LITTLE, | |
142 | }; | |
143 | ||
144 | ||
145 | static struct regmap *vexpress_syscfg_regmap_init(struct device *dev, | |
146 | void *context) | |
147 | { | |
148 | struct platform_device *pdev = to_platform_device(dev); | |
149 | struct vexpress_syscfg *syscfg = context; | |
150 | struct vexpress_syscfg_func *func; | |
151 | struct property *prop; | |
152 | const __be32 *val = NULL; | |
153 | __be32 energy_quirk[4]; | |
154 | int num; | |
155 | u32 site, position, dcc; | |
156 | int i; | |
157 | ||
158 | if (dev->of_node) { | |
159 | int err = vexpress_config_get_topo(dev->of_node, &site, | |
160 | &position, &dcc); | |
161 | ||
162 | if (err) | |
163 | return ERR_PTR(err); | |
164 | ||
165 | prop = of_find_property(dev->of_node, | |
166 | "arm,vexpress-sysreg,func", NULL); | |
167 | if (!prop) | |
168 | return ERR_PTR(-EINVAL); | |
169 | ||
170 | num = prop->length / sizeof(u32) / 2; | |
171 | val = prop->value; | |
172 | } else { | |
173 | if (pdev->num_resources != 1 || | |
174 | pdev->resource[0].flags != IORESOURCE_BUS) | |
175 | return ERR_PTR(-EFAULT); | |
176 | ||
177 | site = pdev->resource[0].start; | |
178 | if (site == VEXPRESS_SITE_MASTER) | |
179 | site = vexpress_config_get_master(); | |
180 | position = 0; | |
181 | dcc = 0; | |
182 | num = 1; | |
183 | } | |
184 | ||
185 | /* | |
186 | * "arm,vexpress-energy" function used to be described | |
187 | * by its first device only, now it requires both | |
188 | */ | |
189 | if (num == 1 && of_device_is_compatible(dev->of_node, | |
190 | "arm,vexpress-energy")) { | |
191 | num = 2; | |
192 | energy_quirk[0] = *val; | |
193 | energy_quirk[2] = *val++; | |
194 | energy_quirk[1] = *val; | |
195 | energy_quirk[3] = cpu_to_be32(be32_to_cpup(val) + 1); | |
196 | val = energy_quirk; | |
197 | } | |
198 | ||
199 | func = kzalloc(sizeof(*func) + sizeof(*func->template) * num, | |
200 | GFP_KERNEL); | |
201 | if (!func) | |
202 | return NULL; | |
203 | ||
204 | func->syscfg = syscfg; | |
205 | func->num_templates = num; | |
206 | ||
207 | for (i = 0; i < num; i++) { | |
208 | u32 function, device; | |
209 | ||
210 | if (dev->of_node) { | |
211 | function = be32_to_cpup(val++); | |
212 | device = be32_to_cpup(val++); | |
213 | } else { | |
214 | function = pdev->resource[0].end; | |
215 | device = pdev->id; | |
216 | } | |
217 | ||
218 | dev_dbg(dev, "func %p: %u/%u/%u/%u/%u\n", | |
219 | func, site, position, dcc, | |
220 | function, device); | |
221 | ||
222 | func->template[i] = SYS_CFGCTRL_DCC(dcc); | |
223 | func->template[i] |= SYS_CFGCTRL_SITE(site); | |
224 | func->template[i] |= SYS_CFGCTRL_POSITION(position); | |
225 | func->template[i] |= SYS_CFGCTRL_FUNC(function); | |
226 | func->template[i] |= SYS_CFGCTRL_DEVICE(device); | |
227 | } | |
228 | ||
229 | vexpress_syscfg_regmap_config.max_register = num - 1; | |
230 | ||
231 | func->regmap = regmap_init(dev, NULL, func, | |
232 | &vexpress_syscfg_regmap_config); | |
233 | ||
234 | if (IS_ERR(func->regmap)) | |
235 | kfree(func); | |
236 | else | |
237 | list_add(&func->list, &syscfg->funcs); | |
238 | ||
239 | return func->regmap; | |
240 | } | |
241 | ||
242 | static void vexpress_syscfg_regmap_exit(struct regmap *regmap, void *context) | |
243 | { | |
244 | struct vexpress_syscfg *syscfg = context; | |
245 | struct vexpress_syscfg_func *func, *tmp; | |
246 | ||
247 | regmap_exit(regmap); | |
248 | ||
249 | list_for_each_entry_safe(func, tmp, &syscfg->funcs, list) { | |
250 | if (func->regmap == regmap) { | |
251 | list_del(&syscfg->funcs); | |
252 | kfree(func); | |
253 | break; | |
254 | } | |
255 | } | |
256 | } | |
257 | ||
258 | static struct vexpress_config_bridge_ops vexpress_syscfg_bridge_ops = { | |
259 | .regmap_init = vexpress_syscfg_regmap_init, | |
260 | .regmap_exit = vexpress_syscfg_regmap_exit, | |
261 | }; | |
262 | ||
263 | ||
264 | /* Non-DT hack, to be gone... */ | |
265 | static struct device *vexpress_syscfg_bridge; | |
266 | ||
267 | int vexpress_syscfg_device_register(struct platform_device *pdev) | |
268 | { | |
269 | pdev->dev.parent = vexpress_syscfg_bridge; | |
270 | ||
271 | return platform_device_register(pdev); | |
272 | } | |
273 | ||
274 | ||
275 | int vexpress_syscfg_probe(struct platform_device *pdev) | |
276 | { | |
277 | struct vexpress_syscfg *syscfg; | |
278 | struct resource *res; | |
279 | struct device *bridge; | |
280 | ||
281 | syscfg = devm_kzalloc(&pdev->dev, sizeof(*syscfg), GFP_KERNEL); | |
282 | if (!syscfg) | |
283 | return -ENOMEM; | |
284 | syscfg->dev = &pdev->dev; | |
285 | INIT_LIST_HEAD(&syscfg->funcs); | |
286 | ||
287 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
288 | if (!devm_request_mem_region(&pdev->dev, res->start, | |
289 | resource_size(res), pdev->name)) | |
290 | return -EBUSY; | |
291 | ||
292 | syscfg->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); | |
293 | if (!syscfg->base) | |
294 | return -EFAULT; | |
295 | ||
296 | /* Must use dev.parent (MFD), as that's where DT phandle points at... */ | |
297 | bridge = vexpress_config_bridge_register(pdev->dev.parent, | |
298 | &vexpress_syscfg_bridge_ops, syscfg); | |
299 | if (IS_ERR(bridge)) | |
300 | return PTR_ERR(bridge); | |
301 | ||
302 | /* Non-DT case */ | |
303 | if (!pdev->dev.of_node) | |
304 | vexpress_syscfg_bridge = bridge; | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
309 | static const struct platform_device_id vexpress_syscfg_id_table[] = { | |
310 | { "vexpress-syscfg", }, | |
311 | {}, | |
312 | }; | |
313 | ||
314 | static struct platform_driver vexpress_syscfg_driver = { | |
315 | .driver.name = "vexpress-syscfg", | |
316 | .id_table = vexpress_syscfg_id_table, | |
317 | .probe = vexpress_syscfg_probe, | |
318 | }; | |
319 | ||
320 | static int __init vexpress_syscfg_init(void) | |
321 | { | |
322 | return platform_driver_register(&vexpress_syscfg_driver); | |
323 | } | |
324 | core_initcall(vexpress_syscfg_init); |