linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 *  Shared Transport Line discipline driver Core

 *  Init Manager module responsible for GPIO control

 *  and firmware download

 *  Copyright (C) 2009-2010 Texas Instruments

 *  Author: Pavan Savoy <pavan_savoy@ti.com>

 */

​

#define pr_fmt(fmt) "(stk) :" fmt

#include <linux/platform_device.h>

#include <linux/jiffies.h>

#include <linux/firmware.h>

#include <linux/delay.h>

#include <linux/wait.h>

#include <linux/gpio.h>

#include <linux/debugfs.h>

#include <linux/seq_file.h>

#include <linux/sched.h>

#include <linux/sysfs.h>

#include <linux/tty.h>

​

#include <linux/skbuff.h>

#include <linux/ti_wilink_st.h>

#include <linux/module.h>

​

#define MAX_ST_DEVICES  3   /* Imagine 1 on each UART for now */

static struct platform_device *st_kim_devices[MAX_ST_DEVICES];

​

/**********************************************************************/

/* internal functions */

​

/**

 * st_get_plat_device -

 *  function which returns the reference to the platform device

 *  requested by id. As of now only 1 such device exists (id=0)

 *  the context requesting for reference can get the id to be

 *  requested by a. The protocol driver which is registering or

 *  b. the tty device which is opened.

 */

static struct platform_device *st_get_plat_device(int id)

{

    return st_kim_devices[id];

}

​

/**

 * validate_firmware_response -

 *  function to return whether the firmware response was proper

 *  in case of error don't complete so that waiting for proper

 *  response times out

 */

static void validate_firmware_response(struct kim_data_s *kim_gdata)

{

    struct sk_buff *skb = kim_gdata->rx_skb;

    if (!skb)

        return;

​

    /* these magic numbers are the position in the response buffer which

     * allows us to distinguish whether the response is for the read

     * version info. command

     */

    if (skb->data[2] == 0x01 && skb->data[3] == 0x01 &&

            skb->data[4] == 0x10 && skb->data[5] == 0x00) {

        /* fw version response */

        memcpy(kim_gdata->resp_buffer,

                kim_gdata->rx_skb->data,

                kim_gdata->rx_skb->len);

        kim_gdata->rx_state = ST_W4_PACKET_TYPE;

        kim_gdata->rx_skb = NULL;

        kim_gdata->rx_count = 0;

    } else if (unlikely(skb->data[5] != 0)) {

        pr_err("no proper response during fw download");

        pr_err("data6 %x", skb->data[5]);

        kfree_skb(skb);

        return;     /* keep waiting for the proper response */

    }

    /* becos of all the script being downloaded */

    complete_all(&kim_gdata->kim_rcvd);

    kfree_skb(skb);

}

​

/* check for data len received inside kim_int_recv

 * most often hit the last case to update state to waiting for data

 */

static inline int kim_check_data_len(struct kim_data_s *kim_gdata, int len)

{

    register int room = skb_tailroom(kim_gdata->rx_skb);

​

    pr_debug("len %d room %d", len, room);

​

    if (!len) {

        validate_firmware_response(kim_gdata);