xref: /openbmc/linux/drivers/soc/sunxi/sunxi_sram.c (revision 110e6f26) 
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 };
27 
28 struct sunxi_sram_data {
29 	char			*name;
30 	u8			reg;
31 	u8			offset;
32 	u8			width;
33 	struct sunxi_sram_func	*func;
34 	struct list_head	list;
35 };
36 
37 struct sunxi_sram_desc {
38 	struct sunxi_sram_data	data;
39 	bool			claimed;
40 };
41 
42 #define SUNXI_SRAM_MAP(_val, _func)				\
43 	{							\
44 		.func = _func,					\
45 		.val = _val,					\
46 	}
47 
48 #define SUNXI_SRAM_DATA(_name, _reg, _off, _width, ...)		\
49 	{							\
50 		.name = _name,					\
51 		.reg = _reg,					\
52 		.offset = _off,					\
53 		.width = _width,				\
54 		.func = (struct sunxi_sram_func[]){		\
55 			__VA_ARGS__, { } },			\
56 	}
57 
58 static struct sunxi_sram_desc sun4i_a10_sram_a3_a4 = {
59 	.data	= SUNXI_SRAM_DATA("A3-A4", 0x4, 0x4, 2,
60 				  SUNXI_SRAM_MAP(0, "cpu"),
61 				  SUNXI_SRAM_MAP(1, "emac")),
62 };
63 
64 static struct sunxi_sram_desc sun4i_a10_sram_d = {
65 	.data	= SUNXI_SRAM_DATA("D", 0x4, 0x0, 1,
66 				  SUNXI_SRAM_MAP(0, "cpu"),
67 				  SUNXI_SRAM_MAP(1, "usb-otg")),
68 };
69 
70 static const struct of_device_id sunxi_sram_dt_ids[] = {
71 	{
72 		.compatible	= "allwinner,sun4i-a10-sram-a3-a4",
73 		.data		= &sun4i_a10_sram_a3_a4.data,
74 	},
75 	{
76 		.compatible	= "allwinner,sun4i-a10-sram-d",
77 		.data		= &sun4i_a10_sram_d.data,
78 	},
79 	{}
80 };
81 
82 static struct device *sram_dev;
83 static LIST_HEAD(claimed_sram);
84 static DEFINE_SPINLOCK(sram_lock);
85 static void __iomem *base;
86 
87 static int sunxi_sram_show(struct seq_file *s, void *data)
88 {
89 	struct device_node *sram_node, *section_node;
90 	const struct sunxi_sram_data *sram_data;
91 	const struct of_device_id *match;
92 	struct sunxi_sram_func *func;
93 	const __be32 *sram_addr_p, *section_addr_p;
94 	u32 val;
95 
96 	seq_puts(s, "Allwinner sunXi SRAM\n");
97 	seq_puts(s, "--------------------\n\n");
98 
99 	for_each_child_of_node(sram_dev->of_node, sram_node) {
100 		sram_addr_p = of_get_address(sram_node, 0, NULL, NULL);
101 
102 		seq_printf(s, "sram@%08x\n",
103 			   be32_to_cpu(*sram_addr_p));
104 
105 		for_each_child_of_node(sram_node, section_node) {
106 			match = of_match_node(sunxi_sram_dt_ids, section_node);
107 			if (!match)
108 				continue;
109 			sram_data = match->data;
110 
111 			section_addr_p = of_get_address(section_node, 0,
112 							NULL, NULL);
113 
114 			seq_printf(s, "\tsection@%04x\t(%s)\n",
115 				   be32_to_cpu(*section_addr_p),
116 				   sram_data->name);
117 
118 			val = readl(base + sram_data->reg);
119 			val >>= sram_data->offset;
120 			val &= GENMASK(sram_data->width - 1, 0);
121 
122 			for (func = sram_data->func; func->func; func++) {
123 				seq_printf(s, "\t\t%s%c\n", func->func,
124 					   func->val == val ? '*' : ' ');
125 			}
126 		}
127 
128 		seq_puts(s, "\n");
129 	}
130 
131 	return 0;
132 }
133 
134 static int sunxi_sram_open(struct inode *inode, struct file *file)
135 {
136 	return single_open(file, sunxi_sram_show, inode->i_private);
137 }
138 
139 static const struct file_operations sunxi_sram_fops = {
140 	.open = sunxi_sram_open,
141 	.read = seq_read,
142 	.llseek = seq_lseek,
143 	.release = single_release,
144 };
145 
146 static inline struct sunxi_sram_desc *to_sram_desc(const struct sunxi_sram_data *data)
147 {
148 	return container_of(data, struct sunxi_sram_desc, data);
149 }
150 
151 static const struct sunxi_sram_data *sunxi_sram_of_parse(struct device_node *node,
152 							 unsigned int *value)
153 {
154 	const struct of_device_id *match;
155 	struct of_phandle_args args;
156 	int ret;
157 
158 	ret = of_parse_phandle_with_fixed_args(node, "allwinner,sram", 1, 0,
159 					       &args);
160 	if (ret)
161 		return ERR_PTR(ret);
162 
163 	if (!of_device_is_available(args.np)) {
164 		ret = -EBUSY;
165 		goto err;
166 	}
167 
168 	if (value)
169 		*value = args.args[0];
170 
171 	match = of_match_node(sunxi_sram_dt_ids, args.np);
172 	if (!match) {
173 		ret = -EINVAL;
174 		goto err;
175 	}
176 
177 	of_node_put(args.np);
178 	return match->data;
179 
180 err:
181 	of_node_put(args.np);
182 	return ERR_PTR(ret);
183 }
184 
185 int sunxi_sram_claim(struct device *dev)
186 {
187 	const struct sunxi_sram_data *sram_data;
188 	struct sunxi_sram_desc *sram_desc;
189 	unsigned int device;
190 	u32 val, mask;
191 
192 	if (IS_ERR(base))
193 		return -EPROBE_DEFER;
194 
195 	if (!dev || !dev->of_node)
196 		return -EINVAL;
197 
198 	sram_data = sunxi_sram_of_parse(dev->of_node, &device);
199 	if (IS_ERR(sram_data))
200 		return PTR_ERR(sram_data);
201 
202 	sram_desc = to_sram_desc(sram_data);
203 
204 	spin_lock(&sram_lock);
205 
206 	if (sram_desc->claimed) {
207 		spin_unlock(&sram_lock);
208 		return -EBUSY;
209 	}
210 
211 	mask = GENMASK(sram_data->offset + sram_data->width - 1,
212 		       sram_data->offset);
213 	val = readl(base + sram_data->reg);
214 	val &= ~mask;
215 	writel(val | ((device << sram_data->offset) & mask),
216 	       base + sram_data->reg);
217 
218 	spin_unlock(&sram_lock);
219 
220 	return 0;
221 }
222 EXPORT_SYMBOL(sunxi_sram_claim);
223 
224 int sunxi_sram_release(struct device *dev)
225 {
226 	const struct sunxi_sram_data *sram_data;
227 	struct sunxi_sram_desc *sram_desc;
228 
229 	if (!dev || !dev->of_node)
230 		return -EINVAL;
231 
232 	sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
233 	if (IS_ERR(sram_data))
234 		return -EINVAL;
235 
236 	sram_desc = to_sram_desc(sram_data);
237 
238 	spin_lock(&sram_lock);
239 	sram_desc->claimed = false;
240 	spin_unlock(&sram_lock);
241 
242 	return 0;
243 }
244 EXPORT_SYMBOL(sunxi_sram_release);
245 
246 static int sunxi_sram_probe(struct platform_device *pdev)
247 {
248 	struct resource *res;
249 	struct dentry *d;
250 
251 	sram_dev = &pdev->dev;
252 
253 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
254 	base = devm_ioremap_resource(&pdev->dev, res);
255 	if (IS_ERR(base))
256 		return PTR_ERR(base);
257 
258 	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
259 
260 	d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
261 				&sunxi_sram_fops);
262 	if (!d)
263 		return -ENOMEM;
264 
265 	return 0;
266 }
267 
268 static const struct of_device_id sunxi_sram_dt_match[] = {
269 	{ .compatible = "allwinner,sun4i-a10-sram-controller" },
270 	{ },
271 };
272 MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
273 
274 static struct platform_driver sunxi_sram_driver = {
275 	.driver = {
276 		.name		= "sunxi-sram",
277 		.of_match_table	= sunxi_sram_dt_match,
278 	},
279 	.probe	= sunxi_sram_probe,
280 };
281 module_platform_driver(sunxi_sram_driver);
282 
283 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
284 MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
285 MODULE_LICENSE("GPL");
286