blob: f9f33496cee98de96e64f0e5b1818a42137b5dc5 [file] [log] [blame]
Michal Simek64b889b2013-03-27 12:37:53 +01001/*
2 * Xilinx SLCR driver
3 *
4 * Copyright (c) 2011-2013 Xilinx Inc.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * You should have received a copy of the GNU General Public
12 * License along with this program; if not, write to the Free
13 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
14 * 02139, USA.
15 */
16
17#include <linux/export.h>
18#include <linux/io.h>
19#include <linux/fs.h>
20#include <linux/interrupt.h>
21#include <linux/init.h>
22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/of_address.h>
25#include <linux/uaccess.h>
26#include <linux/platform_device.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/clk/zynq.h>
30#include "common.h"
31
32#define SLCR_UNLOCK_MAGIC 0xDF0D
33#define SLCR_UNLOCK 0x8 /* SCLR unlock register */
34
35void __iomem *zynq_slcr_base;
36
37/**
38 * zynq_slcr_init
39 * Returns 0 on success, negative errno otherwise.
40 *
41 * Called early during boot from platform code to remap SLCR area.
42 */
43int __init zynq_slcr_init(void)
44{
45 struct device_node *np;
46
47 np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr");
48 if (!np) {
49 pr_err("%s: no slcr node found\n", __func__);
50 BUG();
51 }
52
53 zynq_slcr_base = of_iomap(np, 0);
54 if (!zynq_slcr_base) {
55 pr_err("%s: Unable to map I/O memory\n", __func__);
56 BUG();
57 }
58
59 /* unlock the SLCR so that registers can be changed */
60 writel(SLCR_UNLOCK_MAGIC, zynq_slcr_base + SLCR_UNLOCK);
61
62 pr_info("%s mapped to %p\n", np->name, zynq_slcr_base);
63
64 xilinx_zynq_clocks_init(zynq_slcr_base);
65
66 of_node_put(np);
67
68 return 0;
69}