source: mainline/uspace/srv/hid/kbd/port/niagara.c@ b1bdc7a4

/*
 * Copyright (c) 2008 Pavel Rimsky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup kbd_port
 * @ingroup  kbd
 * @{
 */ 
/** @file
 * @brief       Niagara console keyboard port driver.
 */

#include <as.h>
#include <ddi.h>
#include <async.h>
#include <kbd.h>
#include <kbd_port.h>
#include <sysinfo.h>
#include <stdio.h>
#include <thread.h>
#include <bool.h>
#include <errno.h>

static int niagara_port_init(void);
static void niagara_port_yield(void);
static void niagara_port_reclaim(void);
static void niagara_port_write(uint8_t data);

kbd_port_ops_t niagara_port = {
        .init = niagara_port_init,
        .yield = niagara_port_yield,
        .reclaim = niagara_port_reclaim,
        .write = niagara_port_write
};

#define POLL_INTERVAL  10000

/**
 * Virtual address mapped to the buffer shared with the kernel counterpart.
 */
static uintptr_t input_buffer_addr;

/*
 * Kernel counterpart of the driver pushes characters (it has read) here.
 * Keep in sync with the definition from
 * kernel/arch/sparc64/src/drivers/niagara.c.
 */
#define INPUT_BUFFER_SIZE  ((PAGE_SIZE) - 2 * 8)

typedef volatile struct {
        uint64_t write_ptr;
        uint64_t read_ptr;
        char data[INPUT_BUFFER_SIZE];
}
        __attribute__ ((packed))
        __attribute__ ((aligned(PAGE_SIZE)))
        *input_buffer_t;

/* virtual address of the shared buffer */
static input_buffer_t input_buffer;

static volatile bool polling_disabled = false;
static void niagara_thread_impl(void *arg);

/**
 * Initializes the Niagara driver.
 * Maps the shared buffer and creates the polling thread. 
 */
static int niagara_port_init(void)
{
        sysarg_t paddr;
        if (sysinfo_get_value("niagara.inbuf.address", &paddr) != EOK)
                return -1;
        
        input_buffer_addr = (uintptr_t) as_get_mappable_page(PAGE_SIZE);
        int rc = physmem_map((void *) paddr, (void *) input_buffer_addr,
            1, AS_AREA_READ | AS_AREA_WRITE);
        
        if (rc != 0) {
                printf("Niagara: uspace driver couldn't map physical memory: %d\n",
                    rc);
                return rc;
        }
        
        input_buffer = (input_buffer_t) input_buffer_addr;
        
        thread_id_t tid;
        rc = thread_create(niagara_thread_impl, NULL, "kbd_poll", &tid);
        if (rc != 0)
                return rc;
        
        return 0;
}

static void niagara_port_yield(void)
{
        polling_disabled = true;
}

static void niagara_port_reclaim(void)
{
        polling_disabled = false;
}

static void niagara_port_write(uint8_t data)
{
        (void) data;
}

/**
 * Called regularly by the polling thread. Reads codes of all the
 * pressed keys from the buffer. 
 */
static void niagara_key_pressed(void)
{
        char c;
        
        while (input_buffer->read_ptr != input_buffer->write_ptr) {
                c = input_buffer->data[input_buffer->read_ptr];
                input_buffer->read_ptr =
                        ((input_buffer->read_ptr) + 1) % INPUT_BUFFER_SIZE;
                kbd_push_scancode(c);
        }
}

/**
 * Thread to poll SGCN for keypresses.
 */
static void niagara_thread_impl(void *arg)
{
        (void) arg;

        while (1) {
                if (polling_disabled == false)
                        niagara_key_pressed();
                usleep(POLL_INTERVAL);
        }
}
/** @}
 */