// SPDX-License-Identifier: GPL-2.0-only
/* jazz_esp.c: ESP front-end for MIPS JAZZ systems.
 *
 * Copyright (C) 2007 Thomas Bogendörfer (tsbogend@alpha.frankende)
 */

#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>

#include <asm/irq.h>
#include <asm/io.h>
#include <asm/dma.h>

#include <asm/jazz.h>
#include <asm/jazzdma.h>

#include <scsi/scsi_host.h>

#include "esp_scsi.h"

#define DRV_MODULE_NAME         "jazz_esp"
#define PFX DRV_MODULE_NAME     ": "
#define DRV_VERSION             "1.000"
#define DRV_MODULE_RELDATE      "May 19, 2007"

static void jazz_esp_write8(struct esp *esp, u8 val, unsigned long reg)
{
        *(volatile u8 *)(esp->regs + reg) = val;
}

static u8 jazz_esp_read8(struct esp *esp, unsigned long reg)
{
        return *(volatile u8 *)(esp->regs + reg);
}

static int jazz_esp_irq_pending(struct esp *esp)
{
        if (jazz_esp_read8(esp, ESP_STATUS) & ESP_STAT_INTR)
                return 1;
        return 0;
}

static void jazz_esp_reset_dma(struct esp *esp)
{
        vdma_disable ((int)esp->dma_regs);
}

static void jazz_esp_dma_drain(struct esp *esp)
{
        /* nothing to do */
}

static void jazz_esp_dma_invalidate(struct esp *esp)
{
        vdma_disable ((int)esp->dma_regs);
}

static void jazz_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
                                  u32 dma_count, int write, u8 cmd)
{
        BUG_ON(!(cmd & ESP_CMD_DMA));

        jazz_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
        jazz_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
        vdma_disable ((int)esp->dma_regs);
        if (write)
                vdma_set_mode ((int)esp->dma_regs, DMA_MODE_READ);
        else
                vdma_set_mode ((int)esp->dma_regs, DMA_MODE_WRITE);

        vdma_set_addr ((int)esp->dma_regs, addr);
        vdma_set_count ((int)esp->dma_regs, dma_count);
        vdma_enable ((int)esp->dma_regs);

        scsi_esp_cmd(esp, cmd);
}

static int jazz_esp_dma_error(struct esp *esp)
{
        u32 enable = vdma_get_enable((int)esp->dma_regs);

        if (enable & (R4030_MEM_INTR|R4030_ADDR_INTR))
                return 1;

        return 0;
}

static const struct esp_driver_ops jazz_esp_ops = {
        .esp_write8     =       jazz_esp_write8,
        .esp_read8      =       jazz_esp_read8,
        .irq_pending    =       jazz_esp_irq_pending,
        .reset_dma      =       jazz_esp_reset_dma,
        .dma_drain      =       jazz_esp_dma_drain,
        .dma_invalidate =       jazz_esp_dma_invalidate,
        .send_dma_cmd   =       jazz_esp_send_dma_cmd,
        .dma_error      =       jazz_esp_dma_error,
};

static int esp_jazz_probe(struct platform_device *dev)
{
        const struct scsi_host_template *tpnt = &scsi_esp_template;
        struct Scsi_Host *host;
        struct esp *esp;
        struct resource *res;
        int err;

        host = scsi_host_alloc(tpnt, sizeof(struct esp));

        err = -ENOMEM;
        if (!host)
                goto fail;

        host->max_id = 8;
        esp = shost_priv(host);

        esp->host = host;
        esp->dev = &dev->dev;
        esp->ops = &jazz_esp_ops;

        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
        if (!res)
                goto fail_unlink;

        esp->regs = (void __iomem *)res->start;
        if (!esp->regs)
                goto fail_unlink;

        res = platform_get_resource(dev, IORESOURCE_MEM, 1);
        if (!res)
                goto fail_unlink;

        esp->dma_regs = (void __iomem *)res->start;

        esp->command_block = dma_alloc_coherent(esp->dev, 16,
                                                &esp->command_block_dma,
                                                GFP_KERNEL);
        if (!esp->command_block)
                goto fail_unmap_regs;

        host->irq = err = platform_get_irq(dev, 0);
        if (err < 0)
                goto fail_unmap_command_block;
        err = request_irq(host->irq, scsi_esp_intr, IRQF_SHARED, "ESP", esp);
        if (err < 0)
                goto fail_unmap_command_block;

        esp->scsi_id = 7;
        esp->host->this_id = esp->scsi_id;
        esp->scsi_id_mask = (1 << esp->scsi_id);
        esp->cfreq = 40000000;

        dev_set_drvdata(&dev->dev, esp);

        err = scsi_esp_register(esp);
        if (err)
                goto fail_free_irq;

        return 0;

fail_free_irq:
        free_irq(host->irq, esp);
fail_unmap_command_block:
        dma_free_coherent(esp->dev, 16,
                          esp->command_block,
                          esp->command_block_dma);
fail_unmap_regs:
fail_unlink:
        scsi_host_put(host);
fail:
        return err;
}

static void esp_jazz_remove(struct platform_device *dev)
{
        struct esp *esp = dev_get_drvdata(&dev->dev);
        unsigned int irq = esp->host->irq;

        scsi_esp_unregister(esp);

        free_irq(irq, esp);
        dma_free_coherent(esp->dev, 16,
                          esp->command_block,
                          esp->command_block_dma);

        scsi_host_put(esp->host);
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:jazz_esp");

static struct platform_driver esp_jazz_driver = {
        .probe          = esp_jazz_probe,
        .remove         = esp_jazz_remove,
        .driver = {
                .name   = "jazz_esp",
        },
};
module_platform_driver(esp_jazz_driver);

MODULE_DESCRIPTION("JAZZ ESP SCSI driver");
MODULE_AUTHOR("Thomas Bogendoerfer <tsbogend@alpha.franken.de>");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);