arch/arm/mach-omap1/ocpi.c

   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
  24 #include <mach/hardware.h>
  25
  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_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(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);