3ds_debugboard.c

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/*
 * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
 * Copyright (C) 2010 Jason Wang <[email protected]>
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/smsc911x.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/fixed.h>

#include <mach/hardware.h>

/* LAN9217 ethernet base address */
#define LAN9217_BASE_ADDR(n)    (n + 0x0)
/* External UART */
#define UARTA_BASE_ADDR(n)  (n + 0x8000)
#define UARTB_BASE_ADDR(n)  (n + 0x10000)

#define BOARD_IO_ADDR(n)    (n + 0x20000)
/* LED switchs */
#define LED_SWITCH_REG      0x00
/* buttons */
#define SWITCH_BUTTONS_REG  0x08
/* status, interrupt */
#define INTR_STATUS_REG 0x10
#define INTR_MASK_REG       0x38
#define INTR_RESET_REG      0x20
/* magic word for debug CPLD */
#define MAGIC_NUMBER1_REG   0x40
#define MAGIC_NUMBER2_REG   0x48
/* CPLD code version */
#define CPLD_CODE_VER_REG   0x50
/* magic word for debug CPLD */
#define MAGIC_NUMBER3_REG   0x58
/* module reset register*/
#define MODULE_RESET_REG    0x60
/* CPU ID and Personality ID */
#define MCU_BOARD_ID_REG    0x68

#define MXC_MAX_EXP_IO_LINES    16

/* interrupts like external uart , external ethernet etc*/
#define EXPIO_INT_ENET      0
#define EXPIO_INT_XUART_A   1
#define EXPIO_INT_XUART_B   2
#define EXPIO_INT_BUTTON_A  3
#define EXPIO_INT_BUTTON_B  4

static void __iomem *brd_io;
static struct irq_domain *domain;

static struct resource smsc911x_resources[] = {
    {
        .flags = IORESOURCE_MEM,
    } , {
        .flags = IORESOURCE_IRQ,
    },
};

static struct smsc911x_platform_config smsc911x_config = {
    .irq_polarity = SMSC911X_IRQ_POLARITY_ACTIVE_LOW,
    .flags = SMSC911X_USE_32BIT | SMSC911X_FORCE_INTERNAL_PHY,
};

static struct platform_device smsc_lan9217_device = {
    .name = "smsc911x",
    .id = -1,
    .dev = {
        .platform_data = &smsc911x_config,
    },
    .num_resources = ARRAY_SIZE(smsc911x_resources),
    .resource = smsc911x_resources,
};

static void mxc_expio_irq_handler(u32 irq, struct irq_desc *desc)
{
    u32 imr_val;
    u32 int_valid;
    u32 expio_irq;

    /* irq = gpio irq number */
    desc->irq_data.chip->irq_mask(&desc->irq_data);

    imr_val = __raw_readw(brd_io + INTR_MASK_REG);
    int_valid = __raw_readw(brd_io + INTR_STATUS_REG) & ~imr_val;

    expio_irq = 0;
    for (; int_valid != 0; int_valid >>= 1, expio_irq++) {
        if ((int_valid & 1) == 0)
            continue;
        generic_handle_irq(irq_find_mapping(domain, expio_irq));
    }

    desc->irq_data.chip->irq_ack(&desc->irq_data);
    desc->irq_data.chip->irq_unmask(&desc->irq_data);
}

/*
 * Disable an expio pin's interrupt by setting the bit in the imr.
 * Irq is an expio virtual irq number
 */
static void expio_mask_irq(struct irq_data *d)
{
    u16 reg;
    u32 expio = d->hwirq;

    reg = __raw_readw(brd_io + INTR_MASK_REG);
    reg |= (1 << expio);
    __raw_writew(reg, brd_io + INTR_MASK_REG);
}

static void expio_ack_irq(struct irq_data *d)
{
    u32 expio = d->hwirq;

    __raw_writew(1 << expio, brd_io + INTR_RESET_REG);
    __raw_writew(0, brd_io + INTR_RESET_REG);
    expio_mask_irq(d);
}

static void expio_unmask_irq(struct irq_data *d)
{
    u16 reg;
    u32 expio = d->hwirq;

    reg = __raw_readw(brd_io + INTR_MASK_REG);
    reg &= ~(1 << expio);
    __raw_writew(reg, brd_io + INTR_MASK_REG);
}

static struct irq_chip expio_irq_chip = {
    .irq_ack = expio_ack_irq,
    .irq_mask = expio_mask_irq,
    .irq_unmask = expio_unmask_irq,
};

static struct regulator_consumer_supply dummy_supplies[] = {
    REGULATOR_SUPPLY("vdd33a", "smsc911x"),
    REGULATOR_SUPPLY("vddvario", "smsc911x"),
};

int __init mxc_expio_init(u32 base, u32 intr_gpio)
{
    u32 p_irq = gpio_to_irq(intr_gpio);
    int irq_base;
    int i;

    brd_io = ioremap(BOARD_IO_ADDR(base), SZ_4K);
    if (brd_io == NULL)
        return -ENOMEM;

    if ((__raw_readw(brd_io + MAGIC_NUMBER1_REG) != 0xAAAA) ||
        (__raw_readw(brd_io + MAGIC_NUMBER2_REG) != 0x5555) ||
        (__raw_readw(brd_io + MAGIC_NUMBER3_REG) != 0xCAFE)) {
        pr_info("3-Stack Debug board not detected\n");
        iounmap(brd_io);
        brd_io = NULL;
        return -ENODEV;
    }

    pr_info("3-Stack Debug board detected, rev = 0x%04X\n",
        readw(brd_io + CPLD_CODE_VER_REG));

    /*
     * Configure INT line as GPIO input
     */
    gpio_request(intr_gpio, "expio_pirq");
    gpio_direction_input(intr_gpio);

    /* disable the interrupt and clear the status */
    __raw_writew(0, brd_io + INTR_MASK_REG);
    __raw_writew(0xFFFF, brd_io + INTR_RESET_REG);
    __raw_writew(0, brd_io + INTR_RESET_REG);
    __raw_writew(0x1F, brd_io + INTR_MASK_REG);

    irq_base = irq_alloc_descs(-1, 0, MXC_MAX_EXP_IO_LINES, numa_node_id());
    WARN_ON(irq_base < 0);

    domain = irq_domain_add_legacy(NULL, MXC_MAX_EXP_IO_LINES, irq_base, 0,
                       &irq_domain_simple_ops, NULL);
    WARN_ON(!domain);

    for (i = irq_base; i < irq_base + MXC_MAX_EXP_IO_LINES; i++) {
        irq_set_chip_and_handler(i, &expio_irq_chip, handle_level_irq);
        set_irq_flags(i, IRQF_VALID);
    }
    irq_set_irq_type(p_irq, IRQF_TRIGGER_LOW);
    irq_set_chained_handler(p_irq, mxc_expio_irq_handler);

    /* Register Lan device on the debugboard */
    regulator_register_fixed(0, dummy_supplies, ARRAY_SIZE(dummy_supplies));

    smsc911x_resources[0].start = LAN9217_BASE_ADDR(base);
    smsc911x_resources[0].end = LAN9217_BASE_ADDR(base) + 0x100 - 1;
    smsc911x_resources[1].start = irq_find_mapping(domain, EXPIO_INT_ENET);
    smsc911x_resources[1].end = irq_find_mapping(domain, EXPIO_INT_ENET);
    platform_device_register(&smsc_lan9217_device);

    return 0;
}