source: mainline/kernel/arch/arm32/src/mach/gta02/gta02.c

/*
 * Copyright (c) 2010 Jiri Svoboda
 * 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_gta02
 * @{
 */
/** @file
 *  @brief Openmoko GTA02 (Neo FreeRunner) platform driver.
 */

#include <arch/exception.h>
#include <arch/mach/gta02/gta02.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/drivers/s3c24xx/uart.h>
#include <genarch/drivers/s3c24xx/irqc.h>
#include <genarch/drivers/s3c24xx/timer.h>
#include <genarch/srln/srln.h>
#include <sysinfo/sysinfo.h>
#include <interrupt.h>
#include <ddi/ddi.h>
#include <log.h>

#define GTA02_MEMORY_START      0x30000000      /* physical */
#define GTA02_MEMORY_SIZE       0x08000000      /* 128 MB */
#define GTA02_MEMORY_SKIP       0x8000

/** GTA02 serial console UART address (UART S3C24XX CPU UART channel 2). */
#define GTA02_SCONS_BASE        0x50008000

/** GTA02 framebuffer base address */
#define GTA02_FB_BASE           0x08800000

/** IRQ number used for clock */
#define GTA02_TIMER_IRQ         S3C24XX_INT_TIMER0

static void gta02_init(void);
static void gta02_timer_irq_start(void);
static void gta02_cpu_halt(void);
static void gta02_get_memory_extents(uintptr_t *start, size_t *size);
static void gta02_irq_exception(unsigned int exc_no, istate_t *istate);
static void gta02_frame_init(void);
static void gta02_output_init(void);
static void gta02_input_init(void);
static size_t gta02_get_irq_count(void);
static const char *gta02_get_platform_name(void);

static void gta02_timer_irq_init(void);
static void gta02_timer_start(void);
static irq_ownership_t gta02_timer_irq_claim(irq_t *irq);
static void gta02_timer_irq_handler(irq_t *irq);

static outdev_t *gta02_scons_dev;
static s3c24xx_irqc_t gta02_irqc;
static s3c24xx_timer_t *gta02_timer;

static irq_t gta02_timer_irq;

struct arm_machine_ops gta02_machine_ops = {
        gta02_init,
        gta02_timer_irq_start,
        gta02_cpu_halt,
        gta02_get_memory_extents,
        gta02_irq_exception,
        gta02_frame_init,
        gta02_output_init,
        gta02_input_init,
        gta02_get_irq_count,
        gta02_get_platform_name
};

static void gta02_init(void)
{
        s3c24xx_irqc_regs_t *irqc_regs;

        gta02_timer = (void *) km_map(S3C24XX_TIMER_ADDRESS, PAGE_SIZE,
            PAGE_SIZE, PAGE_NOT_CACHEABLE);
        irqc_regs = (void *) km_map(S3C24XX_IRQC_ADDRESS, PAGE_SIZE, PAGE_SIZE,
            PAGE_NOT_CACHEABLE);

        /* Initialize interrupt controller. */
        s3c24xx_irqc_init(&gta02_irqc, irqc_regs);
}

static void gta02_timer_irq_start(void)
{
        gta02_timer_irq_init();
        gta02_timer_start();
}

static void gta02_cpu_halt(void)
{
}

/** Get extents of available memory.
 *
 * @param start         Place to store memory start address (physical).
 * @param size          Place to store memory size.
 */
static void gta02_get_memory_extents(uintptr_t *start, size_t *size)
{
        *start = GTA02_MEMORY_START + GTA02_MEMORY_SKIP;
        *size  = GTA02_MEMORY_SIZE - GTA02_MEMORY_SKIP;
}

static void gta02_irq_exception(unsigned int exc_no, istate_t *istate)
{
        uint32_t inum;

        /* Determine IRQ number. */
        inum = s3c24xx_irqc_inum_get(&gta02_irqc);

        /* Clear interrupt condition in the interrupt controller. */
        s3c24xx_irqc_clear(&gta02_irqc, inum);

        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 {
                /* Spurious interrupt. */
                log(LF_ARCH, LVL_DEBUG, "cpu%d: spurious interrupt (inum=%d)",
                    CPU->id, inum);
        }
}

static void gta02_frame_init(void)
{
}

static void gta02_output_init(void)
{
#ifdef CONFIG_FB
        fb_properties_t prop = {
                .addr = GTA02_FB_BASE,
                .offset = 0,
                .x = 480,
                .y = 640,
                .scan = 960,
                .visual = VISUAL_RGB_5_6_5_LE
        };

        outdev_t *fb_dev = fb_init(&prop);
        if (fb_dev)
                stdout_wire(fb_dev);
#endif

        /* Initialize serial port of the debugging console. */
        gta02_scons_dev =
            s3c24xx_uart_init(GTA02_SCONS_BASE, S3C24XX_INT_UART2);

        if (gta02_scons_dev) {
                /* Create output device. */
                stdout_wire(gta02_scons_dev);
        }

        /*
         * This is the necessary evil until the userspace driver is entirely
         * self-sufficient.
         */
        sysinfo_set_item_val("s3c24xx_uart", NULL, true);
        sysinfo_set_item_val("s3c24xx_uart.inr", NULL, S3C24XX_INT_UART2);
        sysinfo_set_item_val("s3c24xx_uart.address.physical", NULL,
            (uintptr_t) GTA02_SCONS_BASE);

}

static void gta02_input_init(void)
{
        s3c24xx_uart_t *scons_inst;

        if (gta02_scons_dev) {
                /* Create input device. */
                scons_inst = (void *) gta02_scons_dev->data;

                srln_instance_t *srln_instance = srln_init();
                if (srln_instance) {
                        indev_t *sink = stdin_wire();
                        indev_t *srln = srln_wire(srln_instance, sink);
                        s3c24xx_uart_input_wire(scons_inst, srln);

                        /* Enable interrupts from UART2 */
                        s3c24xx_irqc_src_enable(&gta02_irqc,
                            S3C24XX_INT_UART2);

                        /* Enable interrupts from UART2 RXD */
                        s3c24xx_irqc_subsrc_enable(&gta02_irqc,
                            S3C24XX_SUBINT_RXD2);
                }
        }

        /* Enable interrupts from ADC */
        s3c24xx_irqc_src_enable(&gta02_irqc, S3C24XX_INT_ADC);

        /* Enable interrupts from ADC sub-sources */
        s3c24xx_irqc_subsrc_enable(&gta02_irqc, S3C24XX_SUBINT_ADC_S);
        s3c24xx_irqc_subsrc_enable(&gta02_irqc, S3C24XX_SUBINT_TC);
}

size_t gta02_get_irq_count(void)
{
        return GTA02_IRQ_COUNT;
}

const char *gta02_get_platform_name(void)
{
        return "gta02";
}

static void gta02_timer_irq_init(void)
{
        irq_initialize(&gta02_timer_irq);
        gta02_timer_irq.inr = GTA02_TIMER_IRQ;
        gta02_timer_irq.claim = gta02_timer_irq_claim;
        gta02_timer_irq.handler = gta02_timer_irq_handler;

        irq_register(&gta02_timer_irq);
}

static irq_ownership_t gta02_timer_irq_claim(irq_t *irq)
{
        return IRQ_ACCEPT;
}

static void gta02_timer_irq_handler(irq_t *irq)
{
        /*
         * We are holding a lock which prevents preemption.
         * Release the lock, call clock() and reacquire the lock again.
         */
        irq_spinlock_unlock(&irq->lock, false);
        clock();
        irq_spinlock_lock(&irq->lock, false);
}

static void gta02_timer_start(void)
{
        s3c24xx_timer_t *timer = gta02_timer;

        /*
         * See S3C2442B user manual chapter 10 (PWM Timer) for description
         * of timer operation. Starting a timer is described in the
         * section 'Timer initialization using manual update bit and
         * inverter bit'.
         */

        /*
         * GTA02 PCLK should be 100 MHz.
         * Timer input freq. = PCLK / divider / (1+prescaler)
         * 100 MHz / 2 / (1+7) / 62500 ~= 100 Hz
         */
#if HZ != 100
#warning Other HZ than 100 not suppored.
#endif

        /* Set prescaler values. No pre-divison, no dead zone. */
        pio_write_32(&timer->tcfg0, 7); /* prescale 1/8 */

        /* No DMA request, divider value = 2 for all timers. */
        pio_write_32(&timer->tcfg1, 0);

        /* Stop all timers. */
        pio_write_32(&timer->tcon, 0);

        /* Start counting from 64k-1. Compare value is irrelevant. */
        pio_write_32(&timer->timer[0].cntb, 62500);
        pio_write_32(&timer->timer[0].cmpb, 0);

        /* Enable interrupts from timer0 */
        s3c24xx_irqc_src_enable(&gta02_irqc, S3C24XX_INT_TIMER0);

        /* Load data from tcntb0/tcmpb0 into tcnt0/tcmp0. */
        pio_write_32(&timer->tcon, TCON_T0_AUTO_RLD | TCON_T0_MUPDATE);

        /* Start timer 0. Inverter is off. */
        pio_write_32(&timer->tcon, TCON_T0_AUTO_RLD | TCON_T0_START);
}

/** @}
 */