// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PIKA Warp(tm) board specific routines
 *
 * Copyright (c) 2008-2009 PIKA Technologies
 *   Sean MacLennan <smaclennan@pikatech.com>
 */
#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/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>
#include <asm/dma.h>


static const struct of_device_id warp_of_bus[] __initconst = {
        { .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)
{
        if (!of_machine_is_compatible("pika,warp"))
                return 0;

        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 (of_node_name_eq(child, "green"))
                        green_led = of_get_gpio(child, 0);
                else if (of_node_name_eq(child, "red"))
                        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) {
                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);