xref: /openbmc/linux/drivers/soc/sunxi/sunxi_sram.c (revision f220d3eb)
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 #include <linux/regmap.h>
21 
22 #include <linux/soc/sunxi/sunxi_sram.h>
23 
24 struct sunxi_sram_func {
25 	char	*func;
26 	u8	val;
27 	u32	reg_val;
28 };
29 
30 struct sunxi_sram_data {
31 	char			*name;
32 	u8			reg;
33 	u8			offset;
34 	u8			width;
35 	struct sunxi_sram_func	*func;
36 	struct list_head	list;
37 };
38 
39 struct sunxi_sram_desc {
40 	struct sunxi_sram_data	data;
41 	bool			claimed;
42 };
43 
44 #define SUNXI_SRAM_MAP(_reg_val, _val, _func)			\
45 	{							\
46 		.func = _func,					\
47 		.val = _val,					\
48 		.reg_val = _reg_val,				\
49 	}
50 
51 #define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...)		\
52 	{							\
53 		.name = _name,					\
54 		.reg = _reg,					\
55 		.offset = _off,					\
56 		.width = _width,				\
57 		.func = (struct sunxi_sram_func[]){		\
58 			__VA_ARGS__, { } },			\
59 	}
60 
61 static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
62 	.data	= SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
63 				  SUNXI_SRAM_MAP(0, 0, "cpu"),
64 				  SUNXI_SRAM_MAP(1, 1, "emac")),
65 };
66 
67 static struct sunxi_sram_desc sun4i_a10_sram_c1 = {
68 	.data	= SUNXI_SRAM_DATA("C1", 0x0, 0x0, 31,
69 				  SUNXI_SRAM_MAP(0, 0, "cpu"),
70 				  SUNXI_SRAM_MAP(0x7fffffff, 1, "ve")),
71 };
72 
73 static struct sunxi_sram_desc sun4i_a10_sram_d = {
74 	.data	= SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
75 				  SUNXI_SRAM_MAP(0, 0, "cpu"),
76 				  SUNXI_SRAM_MAP(1, 1, "usb-otg")),
77 };
78 
79 static struct sunxi_sram_desc sun50i_a64_sram_c = {
80 	.data	= SUNXI_SRAM_DATA("C", 0x4, 24, 1,
81 				  SUNXI_SRAM_MAP(0, 1, "cpu"),
82 				  SUNXI_SRAM_MAP(1, 0, "de2")),
83 };
84 
85 static const struct of_device_id sunxi_sram_dt_ids[] = {
86 	{
87 		.compatible	= "allwinner,sun4i-a10-sram-a3-a4",
88 		.data		= &sun4i_a10_sram_a3_a4.data,
89 	},
90 	{
91 		.compatible	= "allwinner,sun4i-a10-sram-c1",
92 		.data		= &sun4i_a10_sram_c1.data,
93 	},
94 	{
95 		.compatible	= "allwinner,sun4i-a10-sram-d",
96 		.data		= &sun4i_a10_sram_d.data,
97 	},
98 	{
99 		.compatible	= "allwinner,sun50i-a64-sram-c",
100 		.data		= &sun50i_a64_sram_c.data,
101 	},
102 	{}
103 };
104 
105 static struct device *sram_dev;
106 static LIST_HEAD(claimed_sram);
107 static DEFINE_SPINLOCK(sram_lock);
108 static void __iomem *base;
109 
110 static int sunxi_sram_show(struct seq_file *s, void *data)
111 {
112 	struct device_node *sram_node, *section_node;
113 	const struct sunxi_sram_data *sram_data;
114 	const struct of_device_id *match;
115 	struct sunxi_sram_func *func;
116 	const __be32 *sram_addr_p, *section_addr_p;
117 	u32 val;
118 
119 	seq_puts(s, "Allwinner sunXi SRAM\n");
120 	seq_puts(s, "--------------------\n\n");
121 
122 	for_each_child_of_node(sram_dev->of_node, sram_node) {
123 		sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
124 
125 		seq_printf(s, "sram@%08x\n",
126 			   be32_to_cpu(*sram_addr_p));
127 
128 		for_each_child_of_node(sram_node, section_node) {
129 			match = of_match_node(sunxi_sram_dt_ids, section_node);
130 			if (!match)
131 				continue;
132 			sram_data = match->data;
133 
134 			section_addr_p = of_get_address(section_node, 0,
135 							NULL, NULL);
136 
137 			seq_printf(s, "\tsection@%04x\t(%s)\n",
138 				   be32_to_cpu(*section_addr_p),
139 				   sram_data->name);
140 
141 			val = readl(base + sram_data->reg);
142 			val >>= sram_data->offset;
143 			val &= GENMASK(sram_data->width - 1, 0);
144 
145 			for (func = sram_data->func; func->func; func++) {
146 				seq_printf(s, "\t\t%s%c\n", func->func,
147 					   func->reg_val == val ?
148 					   '*' : ' ');
149 			}
150 		}
151 
152 		seq_puts(s, "\n");
153 	}
154 
155 	return 0;
156 }
157 
158 static int sunxi_sram_open(struct inode *inode, struct file *file)
159 {
160 	return single_open(file, sunxi_sram_show, inode->i_private);
161 }
162 
163 static const struct file_operations sunxi_sram_fops = {
164 	.open = sunxi_sram_open,
165 	.read = seq_read,
166 	.llseek = seq_lseek,
167 	.release = single_release,
168 };
169 
170 static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
171 {
172 	return container_of(data, struct sunxi_sram_desc, data);
173 }
174 
175 static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
176 							 unsigned int *reg_value)
177 {
178 	const struct of_device_id *match;
179 	const struct sunxi_sram_data *data;
180 	struct sunxi_sram_func *func;
181 	struct of_phandle_args args;
182 	u8 val;
183 	int ret;
184 
185 	ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
186 					       &args);
187 	if (ret)
188 		return ERR_PTR(ret);
189 
190 	if (!of_device_is_available(args.np)) {
191 		ret = -EBUSY;
192 		goto err;
193 	}
194 
195 	val = args.args[0];
196 
197 	match = of_match_node(sunxi_sram_dt_ids, args.np);
198 	if (!match) {
199 		ret = -EINVAL;
200 		goto err;
201 	}
202 
203 	data = match->data;
204 	if (!data) {
205 		ret = -EINVAL;
206 		goto err;
207 	};
208 
209 	for (func = data->func; func->func; func++) {
210 		if (val == func->val) {
211 			if (reg_value)
212 				*reg_value = func->reg_val;
213 
214 			break;
215 		}
216 	}
217 
218 	if (!func->func) {
219 		ret = -EINVAL;
220 		goto err;
221 	}
222 
223 	of_node_put(args.np);
224 	return match->data;
225 
226 err:
227 	of_node_put(args.np);
228 	return ERR_PTR(ret);
229 }
230 
231 int sunxi_sram_claim(struct device *dev)
232 {
233 	const struct sunxi_sram_data *sram_data;
234 	struct sunxi_sram_desc *sram_desc;
235 	unsigned int device;
236 	u32 val, mask;
237 
238 	if (IS_ERR(base))
239 		return PTR_ERR(base);
240 
241 	if (!base)
242 		return -EPROBE_DEFER;
243 
244 	if (!dev || !dev->of_node)
245 		return -EINVAL;
246 
247 	sram_data = sunxi_sram_of_parse(dev->of_node, &device);
248 	if (IS_ERR(sram_data))
249 		return PTR_ERR(sram_data);
250 
251 	sram_desc = to_sram_desc(sram_data);
252 
253 	spin_lock(&sram_lock);
254 
255 	if (sram_desc->claimed) {
256 		spin_unlock(&sram_lock);
257 		return -EBUSY;
258 	}
259 
260 	mask = GENMASK(sram_data->offset + sram_data->width - 1,
261 		       sram_data->offset);
262 	val = readl(base + sram_data->reg);
263 	val &= ~mask;
264 	writel(val | ((device << sram_data->offset) & mask),
265 	       base + sram_data->reg);
266 
267 	spin_unlock(&sram_lock);
268 
269 	return 0;
270 }
271 EXPORT_SYMBOL(sunxi_sram_claim);
272 
273 int sunxi_sram_release(struct device *dev)
274 {
275 	const struct sunxi_sram_data *sram_data;
276 	struct sunxi_sram_desc *sram_desc;
277 
278 	if (!dev || !dev->of_node)
279 		return -EINVAL;
280 
281 	sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
282 	if (IS_ERR(sram_data))
283 		return -EINVAL;
284 
285 	sram_desc = to_sram_desc(sram_data);
286 
287 	spin_lock(&sram_lock);
288 	sram_desc->claimed = false;
289 	spin_unlock(&sram_lock);
290 
291 	return 0;
292 }
293 EXPORT_SYMBOL(sunxi_sram_release);
294 
295 struct sunxi_sramc_variant {
296 	bool has_emac_clock;
297 };
298 
299 static const struct sunxi_sramc_variant sun4i_a10_sramc_variant = {
300 	/* Nothing special */
301 };
302 
303 static const struct sunxi_sramc_variant sun50i_a64_sramc_variant = {
304 	.has_emac_clock = true,
305 };
306 
307 #define SUNXI_SRAM_EMAC_CLOCK_REG	0x30
308 static bool sunxi_sram_regmap_accessible_reg(struct device *dev,
309 					     unsigned int reg)
310 {
311 	if (reg == SUNXI_SRAM_EMAC_CLOCK_REG)
312 		return true;
313 	return false;
314 }
315 
316 static struct regmap_config sunxi_sram_emac_clock_regmap = {
317 	.reg_bits       = 32,
318 	.val_bits       = 32,
319 	.reg_stride     = 4,
320 	/* last defined register */
321 	.max_register   = SUNXI_SRAM_EMAC_CLOCK_REG,
322 	/* other devices have no business accessing other registers */
323 	.readable_reg	= sunxi_sram_regmap_accessible_reg,
324 	.writeable_reg	= sunxi_sram_regmap_accessible_reg,
325 };
326 
327 static int sunxi_sram_probe(struct platform_device *pdev)
328 {
329 	struct resource *res;
330 	struct dentry *d;
331 	struct regmap *emac_clock;
332 	const struct sunxi_sramc_variant *variant;
333 
334 	sram_dev = &pdev->dev;
335 
336 	variant = of_device_get_match_data(&pdev->dev);
337 	if (!variant)
338 		return -EINVAL;
339 
340 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
341 	base = devm_ioremap_resource(&pdev->dev, res);
342 	if (IS_ERR(base))
343 		return PTR_ERR(base);
344 
345 	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
346 
347 	d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
348 				&sunxi_sram_fops);
349 	if (!d)
350 		return -ENOMEM;
351 
352 	if (variant->has_emac_clock) {
353 		emac_clock = devm_regmap_init_mmio(&pdev->dev, base,
354 						   &sunxi_sram_emac_clock_regmap);
355 
356 		if (IS_ERR(emac_clock))
357 			return PTR_ERR(emac_clock);
358 	}
359 
360 	return 0;
361 }
362 
363 static const struct of_device_id sunxi_sram_dt_match[] = {
364 	{
365 		.compatible = "allwinner,sun4i-a10-sram-controller",
366 		.data = &sun4i_a10_sramc_variant,
367 	},
368 	{
369 		.compatible = "allwinner,sun4i-a10-system-control",
370 		.data = &sun4i_a10_sramc_variant,
371 	},
372 	{
373 		.compatible = "allwinner,sun5i-a13-system-control",
374 		.data = &sun4i_a10_sramc_variant,
375 	},
376 	{
377 		.compatible = "allwinner,sun8i-a23-system-control",
378 		.data = &sun4i_a10_sramc_variant,
379 	},
380 	{
381 		.compatible = "allwinner,sun8i-h3-system-control",
382 		.data = &sun4i_a10_sramc_variant,
383 	},
384 	{
385 		.compatible = "allwinner,sun50i-a64-sram-controller",
386 		.data = &sun50i_a64_sramc_variant,
387 	},
388 	{
389 		.compatible = "allwinner,sun50i-a64-system-control",
390 		.data = &sun50i_a64_sramc_variant,
391 	},
392 	{ },
393 };
394 MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
395 
396 static struct platform_driver sunxi_sram_driver = {
397 	.driver = {
398 		.name		= "sunxi-sram",
399 		.of_match_table	= sunxi_sram_dt_match,
400 	},
401 	.probe	= sunxi_sram_probe,
402 };
403 module_platform_driver(sunxi_sram_driver);
404 
405 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
406 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
407 MODULE_LICENSE("GPL");
408