linux-imx

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * IBM Real-Time Linux driver

 *

 * Copyright (C) IBM Corporation, 2010

 *

 * Author: Keith Mannthey <kmannth@us.ibm.com>

 *         Vernon Mauery <vernux@us.ibm.com>

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/kernel.h>

#include <linux/delay.h>

#include <linux/module.h>

#include <linux/io.h>

#include <linux/dmi.h>

#include <linux/efi.h>

#include <linux/mutex.h>

#include <asm/bios_ebda.h>

​

#include <linux/io-64-nonatomic-lo-hi.h>

​

static bool force;

module_param(force, bool, 0);

MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");

​

static bool debug;

module_param(debug, bool, 0644);

MODULE_PARM_DESC(debug, "Show debug output");

​

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");

MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");

​

#define RTL_ADDR_TYPE_IO    1

#define RTL_ADDR_TYPE_MMIO  2

​

#define RTL_CMD_ENTER_PRTM  1

#define RTL_CMD_EXIT_PRTM   2

​

/* The RTL table as presented by the EBDA: */

struct ibm_rtl_table {

    char signature[5]; /* signature should be "_RTL_" */

    u8 version;

    u8 rt_status;

    u8 command;

    u8 command_status;

    u8 cmd_address_type;

    u8 cmd_granularity;

    u8 cmd_offset;

    u16 reserve1;

    u32 cmd_port_address; /* platform dependent address */

    u32 cmd_port_value;   /* platform dependent value */

} __attribute__((packed));

​

/* to locate "_RTL_" signature do a masked 5-byte integer compare */

#define RTL_SIGNATURE 0x0000005f4c54525fULL

#define RTL_MASK      0x000000ffffffffffULL

​

#define RTL_DEBUG(fmt, ...)             \

do {                            \

    if (debug)                  \

        pr_info(fmt, ##__VA_ARGS__);        \

} while (0)

​

static DEFINE_MUTEX(rtl_lock);

static struct ibm_rtl_table __iomem *rtl_table;

static void __iomem *ebda_map;

static void __iomem *rtl_cmd_addr;

static u8 rtl_cmd_type;

static u8 rtl_cmd_width;

​

static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)

{

    if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)

        return ioremap(addr, len);

    return ioport_map(addr, len);

}

​

static void rtl_port_unmap(void __iomem *addr)

{

    if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)

        iounmap(addr);

    else

        ioport_unmap(addr);

}

​

static int ibm_rtl_write(u8 value)

{

    int ret = 0, count = 0;

    u32 cmd_port_val;