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
23struct sunxi_sram_func {
24	char	*func;
25	u8	val;
26};
27
28struct 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
37struct 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
58static 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
64static 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
70static 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
82static struct device *sram_dev;
83static LIST_HEAD(claimed_sram);
84static DEFINE_SPINLOCK(sram_lock);
85static void __iomem *base;
86
87static 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 &= sram_data->width;
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
134static int sunxi_sram_open(struct inode *inode, struct file *file)
135{
136	return single_open(file, sunxi_sram_show, inode->i_private);
137}
138
139static 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
146static 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
151static 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
180err:
181	of_node_put(args.np);
182	return ERR_PTR(ret);
183}
184
185int 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, sram_data->offset);
212	val = readl(base + sram_data->reg);
213	val &= ~mask;
214	writel(val | ((device << sram_data->offset) & mask),
215	       base + sram_data->reg);
216
217	spin_unlock(&sram_lock);
218
219	return 0;
220}
221EXPORT_SYMBOL(sunxi_sram_claim);
222
223int sunxi_sram_release(struct device *dev)
224{
225	const struct sunxi_sram_data *sram_data;
226	struct sunxi_sram_desc *sram_desc;
227
228	if (!dev || !dev->of_node)
229		return -EINVAL;
230
231	sram_data = sunxi_sram_of_parse(dev->of_node, NULL);
232	if (IS_ERR(sram_data))
233		return -EINVAL;
234
235	sram_desc = to_sram_desc(sram_data);
236
237	spin_lock(&sram_lock);
238	sram_desc->claimed = false;
239	spin_unlock(&sram_lock);
240
241	return 0;
242}
243EXPORT_SYMBOL(sunxi_sram_release);
244
245static int sunxi_sram_probe(struct platform_device *pdev)
246{
247	struct resource *res;
248	struct dentry *d;
249
250	sram_dev = &pdev->dev;
251
252	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
253	base = devm_ioremap_resource(&pdev->dev, res);
254	if (IS_ERR(base))
255		return PTR_ERR(base);
256
257	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
258
259	d = debugfs_create_file("sram", S_IRUGO, NULL, NULL,
260				&sunxi_sram_fops);
261	if (!d)
262		return -ENOMEM;
263
264	return 0;
265}
266
267static const struct of_device_id sunxi_sram_dt_match[] = {
268	{ .compatible = "allwinner,sun4i-a10-sram-controller" },
269	{ },
270};
271MODULE_DEVICE_TABLE(of, sunxi_sram_dt_match);
272
273static struct platform_driver sunxi_sram_driver = {
274	.driver = {
275		.name		= "sunxi-sram",
276		.of_match_table	= sunxi_sram_dt_match,
277	},
278	.probe	= sunxi_sram_probe,
279};
280module_platform_driver(sunxi_sram_driver);
281
282MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
283MODULE_DESCRIPTION("Allwinner sunXi SRAM Controller Driver");
284MODULE_LICENSE("GPL");
285