1 /*
2 * Allwinner SoCs SRAM Controller Driver
3 *
4 * Copyright (C) 2015 Maxime Ripard
5 *
6 * Author: Maxime Ripard <maxime.ripard@free-electrons.com>
7 *
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
11 */
12
13 #include <linux/debugfs.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_device.h>
19 #include <linux/platform_device.h>
20
21 #include <linux/soc/sunxi/sunxi_sram.h>
22
23 struct sunxi_sram_func {
24 char *func;
25 u8 val;
26 u32 reg_val;
27 };
28
29 struct sunxi_sram_data {
30 char *name;
31 u8 reg;
32 u8 offset;
33 u8 width;
34 struct sunxi_sram_func *func;
35 struct list_head list;
36 };
37
38 struct sunxi_sram_desc {
39 struct sunxi_sram_data data;
40 bool claimed;
41 };
42
43 #define SUNXI_SRAM_MAP(_reg_val, _val, _func) \
44 { \
45 .func = _func, \
46 .val = _val, \
47 .reg_val = _reg_val, \
48 }
49
50 #define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...) \
51 { \
52 .name = _name, \
53 .reg = _reg, \
54 .offset = _off, \
55 .width = _width, \
56 .func = (struct sunxi_sram_func[]){ \
57 __VA_ARGS__, { } }, \
58 }
59
60 static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
61 .data = SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
62 SUNXI_SRAM_MAP(0, 0, "cpu"),
63 SUNXI_SRAM_MAP(1, 1, "emac")),
64 };
65
66 static struct sunxi_sram_desc sun4i_a10_sram_d = {
67 .data = SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
68 SUNXI_SRAM_MAP(0, 0, "cpu"),
69 SUNXI_SRAM_MAP(1, 1, "usb-otg")),
70 };
71
72 static struct sunxi_sram_desc sun50i_a64_sram_c = {
73 .data = SUNXI_SRAM_DATA("C", 0x4, 24, 1,
74 SUNXI_SRAM_MAP(0, 1, "cpu"),
75 SUNXI_SRAM_MAP(1, 0, "de2")),
76 };
77
78 static const struct of_device_id sunxi_sram_dt_ids[] = {
79 {
80 .compatible = "allwinner,sun4i-a10-sram-a3-a4",
81 .data = &sun4i_a10_sram_a3_a4.data,
82 },
83 {
84 .compatible = "allwinner,sun4i-a10-sram-d",
85 .data = &sun4i_a10_sram_d.data,
86 },
87 {
88 .compatible = "allwinner,sun50i-a64-sram-c",
89 .data = &sun50i_a64_sram_c.data,
90 },
91 {}
92 };
93
94 static struct device *sram_dev;
95 static LIST_HEAD(claimed_sram);
96 static DEFINE_SPINLOCK(sram_lock);
97 static void __iomem *base;
98
sunxi_sram_show(struct seq_file * s,void * data)99 static int sunxi_sram_show(struct seq_file *s, void *data)
100 {
101 struct device_node *sram_node, *section_node;
102 const struct sunxi_sram_data *sram_data;
103 const struct of_device_id *match;
104 struct sunxi_sram_func *func;
105 const __be32 *sram_addr_p, *section_addr_p;
106 u32 val;
107
108 seq_puts(s, "Allwinner sunXi SRAM\n");
109 seq_puts(s, "--------------------\n\n");
110
111 for_each_child_of_node(sram_dev->of_node, sram_node) {
112 sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
113
114 seq_printf(s, "sram@%08x\n",
115 be32_to_cpu(*sram_addr_p));
116
117 for_each_child_of_node(sram_node, section_node) {
118 match = of_match_node(sunxi_sram_dt_ids, section_node);
119 if (!match)
120 continue;
121 sram_data = match->data;
122
123 section_addr_p = of_get_address(section_node, 0,
124 NULL, NULL);
125
126 seq_printf(s, "\tsection@%04x\t(%s)\n",
127 be32_to_cpu(*section_addr_p),
128 sram_data->name);
129
130 val = readl(base + sram_data->reg);
131 val >>= sram_data->offset;
132 val &= GENMASK(sram_data->width - 1, 0);
133
134 for (func = sram_data->func; func->func; func++) {
135 seq_printf(s, "\t\t%s%c\n", func->func,
136 func->reg_val == val ?
137 '*' : ' ');
138 }
139 }
140
141 seq_puts(s, "\n");
142 }
143
144 return 0;
145 }
146
sunxi_sram_open(struct inode * inode,struct file * file)147 static int sunxi_sram_open(struct inode *inode, struct file *file)
148 {
149 return single_open(file, sunxi_sram_show, inode->i_private);
150 }
151
152 static const struct file_operations sunxi_sram_fops = {
153 .open = sunxi_sram_open,
154 .read = seq_read,
155 .llseek = seq_lseek,
156 .release = single_release,
157 };
158
to_sram_desc(const struct sunxi_sram_data * data)159 static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
160 {
161 return container_of(data, struct sunxi_sram_desc, data);
162 }
163
sunxi_sram_of_parse(struct device_node * node,unsigned int * reg_value)164 static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
165 unsigned int *reg_value)
166 {
167 const struct of_device_id *match;
168 const struct sunxi_sram_data *data;
169 struct sunxi_sram_func *func;
170 struct of_phandle_args args;
171 u8 val;
172 int ret;
173
174 ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
175 &args);
176 if (ret)
177 return ERR_PTR(ret);
178
179 if (!of_device_is_available(args.np)) {
180 ret = -EBUSY;
181 goto err;
182 }
183
184 val = args.args[0];
185
186 match = of_match_node(sunxi_sram_dt_ids, args.np);
187 if (!match) {
188 ret = -EINVAL;
189 goto err;
190 }
191
192 data = match->data;
193 if (!data) {
194 ret = -EINVAL;
195 goto err;
196 };
197
198 for (func = data->func; func->func; func++) {
199 if (val == func->val) {
200 if (reg_value)
201 *reg_value = func->reg_val;
202
203 break;
204 }
205 }
206
207 if (!func->func) {
208 ret = -EINVAL;
209 goto err;
210 }
211
212 of_node_put(args.np);
213 return match->data;
214
215 err:
216 of_node_put(args.np);
217 return ERR_PTR(ret);
218 }
219
sunxi_sram_claim(struct device * dev)220 int sunxi_sram_claim(struct device *dev)
221 {
222 const struct sunxi_sram_data *sram_data;
223 struct sunxi_sram_desc *sram_desc;
224 unsigned int device;
225 u32 val, mask;
226
227 if (IS_ERR(base))
228 return PTR_ERR(base);
229
230 if (!base)
231 return -EPROBE_DEFER;
232
233 if (!dev || !dev->of_node)
234 return -EINVAL;
235
236 sram_data = sunxi_sram_of_parse(dev->of_node, &device);
237 if (IS_ERR(sram_data))
238 return PTR_ERR(sram_data);
239
240 sram_desc = to_sram_desc(sram_data);
241
242 spin_lock(&sram_lock);
243
244 if (sram_desc->claimed) {
245 spin_unlock(&sram_lock);
246 return -EBUSY;
247 }
248
249 mask = GENMASK(sram_data->offset + sram_data->width - 1,
250 sram_data->offset);
251 val = readl(base + sram_data->reg);
252 val &= ~mask;
253 writel(val | ((device << sram_data->offset) & mask),
254 base + sram_data->reg);
255
256 spin_unlock(&sram_lock);
257
258 return 0;
259 }
260 EXPORT_SYMBOL(sunxi_sram_claim);
261
sunxi_sram_release(struct device * dev)262 int sunxi_sram_release(struct device *dev)
263 {
264 const struct sunxi_sram_data *sram_data;
265 struct sunxi_sram_desc *sram_desc;
266
267 if (!dev || !dev->of_node)
268 return -EINVAL;
269
270 sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
271 if (IS_ERR(sram_data))
272 return -EINVAL;
273
274 sram_desc = to_sram_desc(sram_data);
275
276 spin_lock(&sram_lock);
277 sram_desc->claimed = false;
278 spin_unlock(&sram_lock);
279
280 return 0;
281 }
282 EXPORT_SYMBOL(sunxi_sram_release);
283
sunxi_sram_probe(struct platform_device * pdev)284 static int sunxi_sram_probe(struct platform_device *pdev)
285 {
286 struct resource *res;
287 struct dentry *d;
288
289 sram_dev = &pdev->dev;
290
291 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
292 base = devm_ioremap_resource(&pdev->dev, res);
293 if (IS_ERR(base))
294 return PTR_ERR(base);
295
296 of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
297
298 d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
299 &sunxi_sram_fops);
300 if (!d)
301 return -ENOMEM;
302
303 return 0;
304 }
305
306 static const struct of_device_id sunxi_sram_dt_match[] = {
307 { .compatible = "allwinner,sun4i-a10-sram-controller" },
308 { .compatible = "allwinner,sun50i-a64-sram-controller" },
309 { },
310 };
311 MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
312
313 static struct platform_driver sunxi_sram_driver = {
314 .driver = {
315 .name = "sunxi-sram",
316 .of_match_table = sunxi_sram_dt_match,
317 },
318 .probe = sunxi_sram_probe,
319 };
320 module_platform_driver(sunxi_sram_driver);
321
322 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
323 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
324 MODULE_LICENSE("GPL");
325