1/*
2 * Copyright (C) 2015 Atmel
3 *
4 * Alexandre Belloni <alexandre.belloni@free-electrons.com
5 * Boris Brezillon <boris.brezillon@free-electrons.com
6 *
7 * This file is licensed under the terms of the GNU General Public
8 * License version 2.  This program is licensed "as is" without any
9 * warranty of any kind, whether express or implied.
10 *
11 */
12
13#define pr_fmt(fmt)	"AT91: " fmt
14
15#include <linux/io.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/of_platform.h>
19#include <linux/slab.h>
20#include <linux/sys_soc.h>
21
22#include "soc.h"
23
24#define AT91_DBGU_CIDR			0x40
25#define AT91_DBGU_CIDR_VERSION(x)	((x) & 0x1f)
26#define AT91_DBGU_CIDR_EXT		BIT(31)
27#define AT91_DBGU_CIDR_MATCH_MASK	0x7fffffe0
28#define AT91_DBGU_EXID			0x44
29
30struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
31{
32	struct soc_device_attribute *soc_dev_attr;
33	const struct at91_soc *soc;
34	struct soc_device *soc_dev;
35	struct device_node *np;
36	void __iomem *regs;
37	u32 cidr, exid;
38
39	np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
40	if (!np)
41		np = of_find_compatible_node(NULL, NULL,
42					     "atmel,at91sam9260-dbgu");
43
44	if (!np) {
45		pr_warn("Could not find DBGU node");
46		return NULL;
47	}
48
49	regs = of_iomap(np, 0);
50	of_node_put(np);
51
52	if (!regs) {
53		pr_warn("Could not map DBGU iomem range");
54		return NULL;
55	}
56
57	cidr = readl(regs + AT91_DBGU_CIDR);
58	exid = readl(regs + AT91_DBGU_EXID);
59
60	iounmap(regs);
61
62	for (soc = socs; soc->name; soc++) {
63		if (soc->cidr_match != (cidr & AT91_DBGU_CIDR_MATCH_MASK))
64			continue;
65
66		if (!(cidr & AT91_DBGU_CIDR_EXT) || soc->exid_match == exid)
67			break;
68	}
69
70	if (!soc->name) {
71		pr_warn("Could not find matching SoC description\n");
72		return NULL;
73	}
74
75	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
76	if (!soc_dev_attr)
77		return NULL;
78
79	soc_dev_attr->family = soc->family;
80	soc_dev_attr->soc_id = soc->name;
81	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
82					   AT91_DBGU_CIDR_VERSION(cidr));
83	soc_dev = soc_device_register(soc_dev_attr);
84	if (IS_ERR(soc_dev)) {
85		kfree(soc_dev_attr->revision);
86		kfree(soc_dev_attr);
87		pr_warn("Could not register SoC device\n");
88		return NULL;
89	}
90
91	if (soc->family)
92		pr_info("Detected SoC family: %s\n", soc->family);
93	pr_info("Detected SoC: %s, revision %X\n", soc->name,
94		AT91_DBGU_CIDR_VERSION(cidr));
95
96	return soc_dev;
97}
98