source: mainline/kernel/arch/arm32/src/mach/raspberrypi/raspberrypi.c@ c5429fe

/*
 * Copyright (c) 2013 Beniamino Galvani
 * 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 kernel_arm32_raspberrypi
 * @{
 */
/** @file
 *  @brief Raspberry PI platform driver.
 */

#include <arch/exception.h>
#include <arch/mach/raspberrypi/raspberrypi.h>
#include <assert.h>
#include <genarch/drivers/pl011/pl011.h>
#include <genarch/drivers/bcm2835/irc.h>
#include <genarch/drivers/bcm2835/timer.h>
#include <genarch/drivers/bcm2835/mbox.h>
#include <arch/mm/page.h>
#include <mm/page.h>
#include <mm/km.h>
#include <genarch/fb/fb.h>
#include <abi/fb/visuals.h>
#include <genarch/srln/srln.h>
#include <stdbool.h>
#include <sysinfo/sysinfo.h>
#include <interrupt.h>
#include <ddi/ddi.h>

#define RPI_DEFAULT_MEMORY_START        0
#define RPI_DEFAULT_MEMORY_SIZE         0x08000000
#define RPI_MEMORY_SKIP                 0x8000

static void raspberrypi_init(void);
static void raspberrypi_timer_irq_start(void);
static void raspberrypi_cpu_halt(void);
static void raspberrypi_get_memory_extents(uintptr_t *start, size_t *size);
static void raspberrypi_irq_exception(unsigned int exc_no, istate_t *istate);
static void raspberrypi_frame_init(void);
static void raspberrypi_output_init(void);
static void raspberrypi_input_init(void);
static size_t raspberrypi_get_irq_count(void);
static const char *raspberrypi_get_platform_name(void);

static struct {
        pl011_uart_t    uart;
        bcm2835_irc_t   *irc;
        bcm2835_timer_t *timer;
} raspi;

struct arm_machine_ops raspberrypi_machine_ops = {
        raspberrypi_init,
        raspberrypi_timer_irq_start,
        raspberrypi_cpu_halt,
        raspberrypi_get_memory_extents,
        raspberrypi_irq_exception,
        raspberrypi_frame_init,
        raspberrypi_output_init,
        raspberrypi_input_init,
        raspberrypi_get_irq_count,
        raspberrypi_get_platform_name
};

static irq_ownership_t raspberrypi_timer_irq_claim(irq_t *irq)
{
        return IRQ_ACCEPT;
}

static void raspberrypi_timer_irq_handler(irq_t *irq)
{
        bcm2835_timer_irq_ack(raspi.timer);
        spinlock_unlock(&irq->lock);
        clock();
        spinlock_lock(&irq->lock);
}

static void raspberrypi_init(void)
{
        /* Initialize interrupt controller */
        raspi.irc = (void *) km_map(BCM2835_IRC_ADDR, sizeof(bcm2835_irc_t),
            KM_NATURAL_ALIGNMENT, PAGE_NOT_CACHEABLE);
        assert(raspi.irc);
        bcm2835_irc_init(raspi.irc);

        /* Initialize system timer */
        raspi.timer = (void *) km_map(BCM2835_TIMER_ADDR,
            sizeof(bcm2835_timer_t), KM_NATURAL_ALIGNMENT, PAGE_NOT_CACHEABLE);
}

static void raspberrypi_timer_irq_start(void)
{
        /* Initialize timer IRQ */
        static irq_t timer_irq;
        irq_initialize(&timer_irq);
        timer_irq.inr = BCM2835_TIMER1_IRQ;
        timer_irq.claim = raspberrypi_timer_irq_claim;
        timer_irq.handler = raspberrypi_timer_irq_handler;
        irq_register(&timer_irq);

        bcm2835_irc_enable(raspi.irc, BCM2835_TIMER1_IRQ);
        bcm2835_timer_start(raspi.timer);
}

static void raspberrypi_cpu_halt(void)
{
        while (true)
                ;
}

/** Get extents of available memory.
 *
 * @param start         Place to store memory start address (physical).
 * @param size          Place to store memory size.
 */
static void raspberrypi_get_memory_extents(uintptr_t *start, size_t *size)
{
        uint32_t mbase, msize;

        if (bcm2835_prop_get_memory(&mbase, &msize)) {
                *start = mbase + RPI_MEMORY_SKIP;
                *size  = msize - RPI_MEMORY_SKIP;
        } else {
                /* Stick to safe default values */
                *start = RPI_DEFAULT_MEMORY_START + RPI_MEMORY_SKIP;
                *size  = RPI_DEFAULT_MEMORY_SIZE - RPI_MEMORY_SKIP;
        }
}

static void raspberrypi_irq_exception(unsigned int exc_no, istate_t *istate)
{
        const unsigned inum = bcm2835_irc_inum_get(raspi.irc);

        irq_t *irq = irq_dispatch_and_lock(inum);
        if (irq) {
                /* The IRQ handler was found. */
                irq->handler(irq);
                spinlock_unlock(&irq->lock);
        } else {
                /* Spurious interrupt.*/
                printf("cpu%d: spurious interrupt (inum=%d)\n", CPU->id, inum);
                bcm2835_irc_disable(raspi.irc, inum);
        }
}

static void raspberrypi_frame_init(void)
{
}

static void raspberrypi_output_init(void)
{
#ifdef CONFIG_FB
        fb_properties_t prop;
        if (bcm2835_fb_init(&prop)) {
                outdev_t *fb_dev = fb_init(&prop);
                if (fb_dev)
                        stdout_wire(fb_dev);
        }
#endif

#ifdef CONFIG_PL011_UART
        if (pl011_uart_init(&raspi.uart, BCM2835_UART_IRQ,
            BCM2835_UART0_BASE_ADDRESS))
                stdout_wire(&raspi.uart.outdev);
#endif
}

static void raspberrypi_input_init(void)
{
        srln_instance_t *srln_instance = srln_init();
        if (srln_instance) {
                indev_t *sink = stdin_wire();
                indev_t *srln = srln_wire(srln_instance, sink);

                pl011_uart_input_wire(&raspi.uart, srln);
                bcm2835_irc_enable(raspi.irc, BCM2835_UART_IRQ);
        }
}

size_t raspberrypi_get_irq_count(void)
{
        return BCM2835_IRQ_COUNT;
}

const char *raspberrypi_get_platform_name(void)
{
        return "raspberrypi";
}

/** @}
 */