warp.c

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/*
 * PIKA Warp(tm) board specific routines
 *
 * Copyright (c) 2008-2009 PIKA Technologies
 *   Sean MacLennan <[email protected]>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */
#include <linux/init.h>
#include <linux/of_platform.h>
#include <linux/kthread.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/of_gpio.h>
#include <linux/of_i2c.h>
#include <linux/slab.h>
#include <linux/export.h>

#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/udbg.h>
#include <asm/time.h>
#include <asm/uic.h>
#include <asm/ppc4xx.h>


static __initdata struct of_device_id warp_of_bus[] = {
    { .compatible = "ibm,plb4", },
    { .compatible = "ibm,opb", },
    { .compatible = "ibm,ebc", },
    {},
};

static int __init warp_device_probe(void)
{
    of_platform_bus_probe(NULL, warp_of_bus, NULL);
    return 0;
}
machine_device_initcall(warp, warp_device_probe);

static int __init warp_probe(void)
{
    unsigned long root = of_get_flat_dt_root();

    if (!of_flat_dt_is_compatible(root, "pika,warp"))
        return 0;

    /* For __dma_alloc_coherent */
    ISA_DMA_THRESHOLD = ~0L;

    return 1;
}

define_machine(warp) {
    .name       = "Warp",
    .probe      = warp_probe,
    .progress   = udbg_progress,
    .init_IRQ   = uic_init_tree,
    .get_irq    = uic_get_irq,
    .restart    = ppc4xx_reset_system,
    .calibrate_decr = generic_calibrate_decr,
};


static int __init warp_post_info(void)
{
    struct device_node *np;
    void __iomem *fpga;
    u32 post1, post2;

    /* Sighhhh... POST information is in the sd area. */
    np = of_find_compatible_node(NULL, NULL, "pika,fpga-sd");
    if (np == NULL)
        return -ENOENT;

    fpga = of_iomap(np, 0);
    of_node_put(np);
    if (fpga == NULL)
        return -ENOENT;

    post1 = in_be32(fpga + 0x40);
    post2 = in_be32(fpga + 0x44);

    iounmap(fpga);

    if (post1 || post2)
        printk(KERN_INFO "Warp POST %08x %08x\n", post1, post2);
    else
        printk(KERN_INFO "Warp POST OK\n");

    return 0;
}


#ifdef CONFIG_SENSORS_AD7414

static LIST_HEAD(dtm_shutdown_list);
static void __iomem *dtm_fpga;
static unsigned green_led, red_led;


struct dtm_shutdown {
    struct list_head list;
    void (*func)(void *arg);
    void *arg;
};


int pika_dtm_register_shutdown(void (*func)(void *arg), void *arg)
{
    struct dtm_shutdown *shutdown;

    shutdown = kmalloc(sizeof(struct dtm_shutdown), GFP_KERNEL);
    if (shutdown == NULL)
        return -ENOMEM;

    shutdown->func = func;
    shutdown->arg = arg;

    list_add(&shutdown->list, &dtm_shutdown_list);

    return 0;
}

int pika_dtm_unregister_shutdown(void (*func)(void *arg), void *arg)
{
    struct dtm_shutdown *shutdown;

    list_for_each_entry(shutdown, &dtm_shutdown_list, list)
        if (shutdown->func == func && shutdown->arg == arg) {
            list_del(&shutdown->list);
            kfree(shutdown);
            return 0;
        }

    return -EINVAL;
}

static irqreturn_t temp_isr(int irq, void *context)
{
    struct dtm_shutdown *shutdown;
    int value = 1;

    local_irq_disable();

    gpio_set_value(green_led, 0);

    /* Run through the shutdown list. */
    list_for_each_entry(shutdown, &dtm_shutdown_list, list)
        shutdown->func(shutdown->arg);

    printk(KERN_EMERG "\n\nCritical Temperature Shutdown\n\n");

    while (1) {
        if (dtm_fpga) {
            unsigned reset = in_be32(dtm_fpga + 0x14);
            out_be32(dtm_fpga + 0x14, reset);
        }

        gpio_set_value(red_led, value);
        value ^= 1;
        mdelay(500);
    }

    /* Not reached */
    return IRQ_HANDLED;
}

static int pika_setup_leds(void)
{
    struct device_node *np, *child;

    np = of_find_compatible_node(NULL, NULL, "gpio-leds");
    if (!np) {
        printk(KERN_ERR __FILE__ ": Unable to find leds\n");
        return -ENOENT;
    }

    for_each_child_of_node(np, child)
        if (strcmp(child->name, "green") == 0)
            green_led = of_get_gpio(child, 0);
        else if (strcmp(child->name, "red") == 0)
            red_led = of_get_gpio(child, 0);

    of_node_put(np);

    return 0;
}

static void pika_setup_critical_temp(struct device_node *np,
                     struct i2c_client *client)
{
    int irq, rc;

    /* Do this before enabling critical temp interrupt since we
     * may immediately interrupt.
     */
    pika_setup_leds();

    /* These registers are in 1 degree increments. */
    i2c_smbus_write_byte_data(client, 2, 65); /* Thigh */
    i2c_smbus_write_byte_data(client, 3,  0); /* Tlow */

    irq = irq_of_parse_and_map(np, 0);
    if (irq  == NO_IRQ) {
        printk(KERN_ERR __FILE__ ": Unable to get ad7414 irq\n");
        return;
    }

    rc = request_irq(irq, temp_isr, 0, "ad7414", NULL);
    if (rc) {
        printk(KERN_ERR __FILE__
               ": Unable to request ad7414 irq %d = %d\n", irq, rc);
        return;
    }
}

static inline void pika_dtm_check_fan(void __iomem *fpga)
{
    static int fan_state;
    u32 fan = in_be32(fpga + 0x34) & (1 << 14);

    if (fan_state != fan) {
        fan_state = fan;
        if (fan)
            printk(KERN_WARNING "Fan rotation error detected."
                   " Please check hardware.\n");
    }
}

static int pika_dtm_thread(void __iomem *fpga)
{
    struct device_node *np;
    struct i2c_client *client;

    np = of_find_compatible_node(NULL, NULL, "adi,ad7414");
    if (np == NULL)
        return -ENOENT;

    client = of_find_i2c_device_by_node(np);
    if (client == NULL) {
        of_node_put(np);
        return -ENOENT;
    }

    pika_setup_critical_temp(np, client);

    of_node_put(np);

    printk(KERN_INFO "Warp DTM thread running.\n");

    while (!kthread_should_stop()) {
        int val;

        val = i2c_smbus_read_word_data(client, 0);
        if (val < 0)
            dev_dbg(&client->dev, "DTM read temp failed.\n");
        else {
            s16 temp = swab16(val);
            out_be32(fpga + 0x20, temp);
        }

        pika_dtm_check_fan(fpga);

        set_current_state(TASK_INTERRUPTIBLE);
        schedule_timeout(HZ);
    }

    return 0;
}

static int __init pika_dtm_start(void)
{
    struct task_struct *dtm_thread;
    struct device_node *np;

    np = of_find_compatible_node(NULL, NULL, "pika,fpga");
    if (np == NULL)
        return -ENOENT;

    dtm_fpga = of_iomap(np, 0);
    of_node_put(np);
    if (dtm_fpga == NULL)
        return -ENOENT;

    /* Must get post info before thread starts. */
    warp_post_info();

    dtm_thread = kthread_run(pika_dtm_thread, dtm_fpga, "pika-dtm");
    if (IS_ERR(dtm_thread)) {
        iounmap(dtm_fpga);
        return PTR_ERR(dtm_thread);
    }

    return 0;
}
machine_late_initcall(warp, pika_dtm_start);

#else /* !CONFIG_SENSORS_AD7414 */

int pika_dtm_register_shutdown(void (*func)(void *arg), void *arg)
{
    return 0;
}

int pika_dtm_unregister_shutdown(void (*func)(void *arg), void *arg)
{
    return 0;
}

machine_late_initcall(warp, warp_post_info);

#endif

EXPORT_SYMBOL(pika_dtm_register_shutdown);
EXPORT_SYMBOL(pika_dtm_unregister_shutdown);