source: mainline/kernel/arch/arm32/src/mach/beaglebone/beaglebone.c@ b67ce1ff

/*
 * Copyright (c) 2012 Matteo Facchinetti
 * Copyright (c) 2012 Maurizio Lombardi
 * 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_beaglebone
 * @{
 */
/** @file
 *  @brief BeagleBone platform driver.
 */

#include <arch/exception.h>
#include <arch/mach/beaglebone/beaglebone.h>
#include <assert.h>
#include <genarch/drivers/am335x/irc.h>
#include <genarch/drivers/am335x/uart.h>
#include <genarch/drivers/am335x/timer.h>
#include <genarch/drivers/am335x/cm_per.h>
#include <genarch/drivers/am335x/cm_dpll.h>
#include <genarch/drivers/am335x/ctrl_module.h>
#include <genarch/srln/srln.h>
#include <interrupt.h>
#include <ddi/ddi.h>
#include <mm/km.h>
#include <stdbool.h>

#define BBONE_MEMORY_START       0x80000000      /* physical */
#define BBONE_MEMORY_SIZE        0x10000000      /* 256 MB */

static void bbone_init(void);
static void bbone_timer_irq_start(void);
static void bbone_cpu_halt(void);
static void bbone_get_memory_extents(uintptr_t *start, size_t *size);
static void bbone_irq_exception(unsigned int exc_no, istate_t *istate);
static void bbone_frame_init(void);
static void bbone_output_init(void);
static void bbone_input_init(void);
static size_t bbone_get_irq_count(void);
static const char *bbone_get_platform_name(void);

static struct beaglebone {
        omap_irc_regs_t *irc_addr;
        am335x_cm_per_regs_t *cm_per_addr;
        am335x_cm_dpll_regs_t *cm_dpll_addr;
        am335x_ctrl_module_t  *ctrl_module;
        am335x_timer_t timer;
        omap_uart_t uart;
} bbone;

struct arm_machine_ops bbone_machine_ops = {
        .machine_init = bbone_init,
        .machine_timer_irq_start = bbone_timer_irq_start,
        .machine_cpu_halt = bbone_cpu_halt,
        .machine_get_memory_extents = bbone_get_memory_extents,
        .machine_irq_exception = bbone_irq_exception,
        .machine_frame_init = bbone_frame_init,
        .machine_output_init = bbone_output_init,
        .machine_input_init = bbone_input_init,
        .machine_get_irq_count = bbone_get_irq_count,
        .machine_get_platform_name = bbone_get_platform_name,
};

static void bbone_init(void)
{
        bbone.irc_addr = (void *) km_map(AM335x_IRC_BASE_ADDRESS,
            AM335x_IRC_SIZE, KM_NATURAL_ALIGNMENT, PAGE_NOT_CACHEABLE);

        bbone.cm_per_addr = (void *) km_map(AM335x_CM_PER_BASE_ADDRESS,
            AM335x_CM_PER_SIZE, KM_NATURAL_ALIGNMENT, PAGE_NOT_CACHEABLE);

        bbone.cm_dpll_addr = (void *) km_map(AM335x_CM_DPLL_BASE_ADDRESS,
            AM335x_CM_DPLL_SIZE, KM_NATURAL_ALIGNMENT, PAGE_NOT_CACHEABLE);

        bbone.ctrl_module = (void *) km_map(AM335x_CTRL_MODULE_BASE_ADDRESS,
            AM335x_CTRL_MODULE_SIZE, KM_NATURAL_ALIGNMENT,
            PAGE_NOT_CACHEABLE);

        assert(bbone.irc_addr != NULL);
        assert(bbone.cm_per_addr != NULL);
        assert(bbone.cm_dpll_addr != NULL);
        assert(bbone.ctrl_module != NULL);

        /* Initialize the interrupt controller */
        omap_irc_init(bbone.irc_addr);
}

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

static void bbone_timer_irq_handler(irq_t *irq)
{
        am335x_timer_intr_ack(&bbone.timer);
        irq_spinlock_unlock(&irq->lock, false);
        clock();
        irq_spinlock_lock(&irq->lock, false);
}

static void bbone_timer_irq_start(void)
{
        unsigned sysclk_freq;
        errno_t rc;

        /* Initialize the IRQ */
        static irq_t timer_irq;
        irq_initialize(&timer_irq);
        timer_irq.inr = AM335x_DMTIMER2_IRQ;
        timer_irq.claim = bbone_timer_irq_claim;
        timer_irq.handler = bbone_timer_irq_handler;
        irq_register(&timer_irq);

        /* Enable the DMTIMER2 clock module */
        am335x_clock_module_enable(bbone.cm_per_addr, DMTIMER2);
        /* Select the SYSCLK as the clock source for the dmtimer2 module */
        am335x_clock_source_select(bbone.cm_dpll_addr, DMTIMER2,
            CLK_SRC_M_OSC);
        /* Initialize the DMTIMER2 */
        if (am335x_ctrl_module_clock_freq_get(bbone.ctrl_module,
            &sysclk_freq) != EOK) {
                printf("Cannot get the system clock frequency!\n");
                return;
        } else
                printf("system clock running at %u hz\n", sysclk_freq);

        rc = am335x_timer_init(&bbone.timer, DMTIMER2, HZ, sysclk_freq);
        if (rc != EOK) {
                printf("Timer initialization failed\n");
                return;
        }
        /* Enable the interrupt */
        omap_irc_enable(bbone.irc_addr, AM335x_DMTIMER2_IRQ);
        /* Start the timer */
        am335x_timer_start(&bbone.timer);
}

static void bbone_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 bbone_get_memory_extents(uintptr_t *start, size_t *size)
{
        *start = BBONE_MEMORY_START;
        *size  = BBONE_MEMORY_SIZE;
}

static void bbone_irq_exception(unsigned int exc_no, istate_t *istate)
{
        const unsigned inum = omap_irc_inum_get(bbone.irc_addr);

        irq_t *irq = irq_dispatch_and_lock(inum);
        if (irq) {
                /* The IRQ handler was found. */
                irq->handler(irq);
                irq_spinlock_unlock(&irq->lock, false);
        } else {
                printf("Spurious interrupt\n");
        }

        omap_irc_irq_ack(bbone.irc_addr);
}

static void bbone_frame_init(void)
{
}

static void bbone_output_init(void)
{
#ifdef CONFIG_OMAP_UART
        const bool ok = omap_uart_init(&bbone.uart,
            AM335x_UART0_IRQ, AM335x_UART0_BASE_ADDRESS,
            AM335x_UART0_SIZE);

        if (ok)
                stdout_wire(&bbone.uart.outdev);
#endif
}

static void bbone_input_init(void)
{
#ifdef CONFIG_OMAP_UART
        srln_instance_t *srln_instance = srln_init();
        if (srln_instance) {
                indev_t *sink = stdin_wire();
                indev_t *srln = srln_wire(srln_instance, sink);
                omap_uart_input_wire(&bbone.uart, srln);
                omap_irc_enable(bbone.irc_addr, AM335x_UART0_IRQ);
        }
#endif
}

size_t bbone_get_irq_count(void)
{
        return AM335x_IRC_IRQ_COUNT;
}

const char *bbone_get_platform_name(void)
{
        return "beaglebone";
}

/**
 * @}
 */