xref: /openbmc/linux/arch/arm/mach-omap1/ocpi.c (revision e65e175b)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * linux/arch/arm/plat-omap/ocpi.c
4  *
5  * Minimal OCP bus support for omap16xx
6  *
7  * Copyright (C) 2003 - 2005 Nokia Corporation
8  * Copyright (C) 2012 Texas Instruments, Inc.
9  * Written by Tony Lindgren <tony@atomide.com>
10  *
11  * Modified for clock framework by Paul Mundt <paul.mundt@nokia.com>.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/types.h>
16 #include <linux/errno.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/err.h>
21 #include <linux/clk.h>
22 #include <linux/io.h>
23 #include <linux/soc/ti/omap1-io.h>
24 
25 #include "hardware.h"
26 #include "common.h"
27 
28 #define OCPI_BASE		0xfffec320
29 #define OCPI_FAULT		(OCPI_BASE + 0x00)
30 #define OCPI_CMD_FAULT		(OCPI_BASE + 0x04)
31 #define OCPI_SINT0		(OCPI_BASE + 0x08)
32 #define OCPI_TABORT		(OCPI_BASE + 0x0c)
33 #define OCPI_SINT1		(OCPI_BASE + 0x10)
34 #define OCPI_PROT		(OCPI_BASE + 0x14)
35 #define OCPI_SEC		(OCPI_BASE + 0x18)
36 
37 /* USB OHCI OCPI access error registers */
38 #define HOSTUEADDR	0xfffba0e0
39 #define HOSTUESTATUS	0xfffba0e4
40 
41 static struct clk *ocpi_ck;
42 
43 /*
44  * Enables device access to OMAP buses via the OCPI bridge
45  */
46 int ocpi_enable(void)
47 {
48 	unsigned int val;
49 
50 	if (!cpu_is_omap16xx())
51 		return -ENODEV;
52 
53 	/* Enable access for OHCI in OCPI */
54 	val = omap_readl(OCPI_PROT);
55 	val &= ~0xff;
56 	/* val &= (1 << 0);	 Allow access only to EMIFS */
57 	omap_writel(val, OCPI_PROT);
58 
59 	val = omap_readl(OCPI_SEC);
60 	val &= ~0xff;
61 	omap_writel(val, OCPI_SEC);
62 
63 	return 0;
64 }
65 EXPORT_SYMBOL(ocpi_enable);
66 
67 static int __init omap_ocpi_init(void)
68 {
69 	if (!cpu_is_omap16xx())
70 		return -ENODEV;
71 
72 	ocpi_ck = clk_get(NULL, "l3_ocpi_ck");
73 	if (IS_ERR(ocpi_ck))
74 		return PTR_ERR(ocpi_ck);
75 
76 	clk_prepare_enable(ocpi_ck);
77 	ocpi_enable();
78 	pr_info("OMAP OCPI interconnect driver loaded\n");
79 
80 	return 0;
81 }
82 
83 static void __exit omap_ocpi_exit(void)
84 {
85 	/* REVISIT: Disable OCPI */
86 
87 	if (!cpu_is_omap16xx())
88 		return;
89 
90 	clk_disable_unprepare(ocpi_ck);
91 	clk_put(ocpi_ck);
92 }
93 
94 MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
95 MODULE_DESCRIPTION("OMAP OCPI bus controller module");
96 MODULE_LICENSE("GPL");
97 module_init(omap_ocpi_init);
98 module_exit(omap_ocpi_exit);
99