linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (C) 2007 Google, Inc.

 * Copyright (C) 2012 Intel, Inc.

 * Copyright (C) 2017 Imagination Technologies Ltd.

 */

​

#include <linux/console.h>

#include <linux/interrupt.h>

#include <linux/platform_device.h>

#include <linux/tty.h>

#include <linux/tty_flip.h>

#include <linux/slab.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/mod_devicetable.h>

#include <linux/goldfish.h>

#include <linux/mm.h>

#include <linux/dma-mapping.h>

#include <linux/serial_core.h>

​

/* Goldfish tty register's offsets */

#define GOLDFISH_TTY_REG_BYTES_READY    0x04

#define GOLDFISH_TTY_REG_CMD        0x08

#define GOLDFISH_TTY_REG_DATA_PTR   0x10

#define GOLDFISH_TTY_REG_DATA_LEN   0x14

#define GOLDFISH_TTY_REG_DATA_PTR_HIGH  0x18

#define GOLDFISH_TTY_REG_VERSION    0x20

​

/* Goldfish tty commands */

#define GOLDFISH_TTY_CMD_INT_DISABLE    0

#define GOLDFISH_TTY_CMD_INT_ENABLE 1

#define GOLDFISH_TTY_CMD_WRITE_BUFFER   2

#define GOLDFISH_TTY_CMD_READ_BUFFER    3

​

struct goldfish_tty {

    struct tty_port port;

    spinlock_t lock;

    void __iomem *base;

    u32 irq;

    int opencount;

    struct console console;

    u32 version;

    struct device *dev;

};

​

static DEFINE_MUTEX(goldfish_tty_lock);

static struct tty_driver *goldfish_tty_driver;

static u32 goldfish_tty_line_count = 8;

static u32 goldfish_tty_current_line_count;

static struct goldfish_tty *goldfish_ttys;

​

static void do_rw_io(struct goldfish_tty *qtty,

             unsigned long address,

             unsigned int count,

             int is_write)

{

    unsigned long irq_flags;

    void __iomem *base = qtty->base;

​

    spin_lock_irqsave(&qtty->lock, irq_flags);

    gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,

             base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);

    writel(count, base + GOLDFISH_TTY_REG_DATA_LEN);

​

    if (is_write)

        writel(GOLDFISH_TTY_CMD_WRITE_BUFFER,

               base + GOLDFISH_TTY_REG_CMD);

    else

        writel(GOLDFISH_TTY_CMD_READ_BUFFER,

               base + GOLDFISH_TTY_REG_CMD);

​

    spin_unlock_irqrestore(&qtty->lock, irq_flags);

}

​

static void goldfish_tty_rw(struct goldfish_tty *qtty,

                unsigned long addr,

                unsigned int count,

                int is_write)

{

    dma_addr_t dma_handle;

    enum dma_data_direction dma_dir;

​

    dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);

    if (qtty->version > 0) {

        /*

         * Goldfish TTY for Ranchu platform uses

         * physical addresses and DMA for read/write operations

         */

        unsigned long addr_end = addr + count;

​

        while (addr < addr_end) {