drivers/net/wwan/t7xx/t7xx_port_wwan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2021, MediaTek Inc.
   4  * Copyright (c) 2021-2022, Intel Corporation.
   5  *
   6  * Authors:
   7  *  Amir Hanania <amir.hanania@intel.com>
   8  *  Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
   9  *  Haijun Liu <haijun.liu@mediatek.com>
  10  *  Moises Veleta <moises.veleta@intel.com>
  11  *  Ricardo Martinez <ricardo.martinez@linux.intel.com>
  12  *
  13  * Contributors:
  14  *  Andy Shevchenko <andriy.shevchenko@linux.intel.com>
  15  *  Chiranjeevi Rapolu <chiranjeevi.rapolu@intel.com>
  16  *  Eliot Lee <eliot.lee@intel.com>
  17  *  Sreehari Kancharla <sreehari.kancharla@intel.com>
  18  */
  19
  20 #include <linux/atomic.h>
  21 #include <linux/bitfield.h>
  22 #include <linux/dev_printk.h>
  23 #include <linux/err.h>
  24 #include <linux/gfp.h>
  25 #include <linux/minmax.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/string.h>
  30 #include <linux/wwan.h>
  31
  32 #include "t7xx_port.h"
  33 #include "t7xx_port_proxy.h"
  34 #include "t7xx_state_monitor.h"
  35
  36 static int t7xx_port_ctrl_start(struct wwan_port *port)
  37 {
  38         struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
  39
  40         if (atomic_read(&port_mtk->usage_cnt))
  41                 return -EBUSY;
  42
  43         atomic_inc(&port_mtk->usage_cnt);
  44         return 0;
  45 }
  46
  47 static void t7xx_port_ctrl_stop(struct wwan_port *port)
  48 {
  49         struct t7xx_port *port_mtk = wwan_port_get_drvdata(port);
  50
  51         atomic_dec(&port_mtk->usage_cnt);
  52 }
  53
  54 static int t7xx_port_ctrl_tx(struct wwan_port *port, struct sk_buff *skb)
  55 {
  56         struct t7xx_port *port_private = wwan_port_get_drvdata(port);
  57         const struct t7xx_port_conf *port_conf;
  58         struct sk_buff *cur = skb, *cloned;
  59         struct t7xx_fsm_ctl *ctl;
  60         enum md_state md_state;
  61         int cnt = 0, ret;
  62
  63         if (!port_private->chan_enable)
  64                 return -EINVAL;
  65
  66         port_conf = port_private->port_conf;
  67         ctl = port_private->t7xx_dev->md->fsm_ctl;
  68         md_state = t7xx_fsm_get_md_state(ctl);
  69         if (md_state == MD_STATE_WAITING_FOR_HS1 || md_state == MD_STATE_WAITING_FOR_HS2) {
  70                 dev_warn(port_private->dev, "Cannot write to %s port when md_state=%d\n",
  71                          port_conf->name, md_state);
  72                 return -ENODEV;
  73         }
  74
  75         while (cur) {
  76                 cloned = skb_clone(cur, GFP_KERNEL);
  77                 cloned->len = skb_headlen(cur);
  78                 ret = t7xx_port_send_skb(port_private, cloned, 0, 0);
  79                 if (ret) {
  80                         dev_kfree_skb(cloned);
  81                         dev_err(port_private->dev, "Write error on %s port, %d\n",
  82                                 port_conf->name, ret);
  83                         return cnt ? cnt + ret : ret;
  84                 }
  85                 cnt += cur->len;
  86                 if (cur == skb)
  87                         cur = skb_shinfo(skb)->frag_list;
  88                 else
  89                         cur = cur->next;
  90         }
  91
  92         dev_kfree_skb(skb);
  93         return 0;
  94 }
  95
  96 static const struct wwan_port_ops wwan_ops = {
  97         .start = t7xx_port_ctrl_start,
  98         .stop = t7xx_port_ctrl_stop,
  99         .tx = t7xx_port_ctrl_tx,
 100 };
 101
 102 static int t7xx_port_wwan_init(struct t7xx_port *port)
 103 {
 104         port->rx_length_th = RX_QUEUE_MAXLEN;
 105         return 0;
 106 }
 107
 108 static void t7xx_port_wwan_uninit(struct t7xx_port *port)
 109 {
 110         if (!port->wwan.wwan_port)
 111                 return;
 112
 113         port->rx_length_th = 0;
 114         wwan_remove_port(port->wwan.wwan_port);
 115         port->wwan.wwan_port = NULL;
 116 }
 117
 118 static int t7xx_port_wwan_recv_skb(struct t7xx_port *port, struct sk_buff *skb)
 119 {
 120         if (!atomic_read(&port->usage_cnt) || !port->chan_enable) {
 121                 const struct t7xx_port_conf *port_conf = port->port_conf;
 122
 123                 dev_kfree_skb_any(skb);
 124                 dev_err_ratelimited(port->dev, "Port %s is not opened, drop packets\n",
 125                                     port_conf->name);
 126                 /* Dropping skb, caller should not access skb.*/
 127                 return 0;
 128         }
 129
 130         wwan_port_rx(port->wwan.wwan_port, skb);
 131         return 0;
 132 }
 133
 134 static int t7xx_port_wwan_enable_chl(struct t7xx_port *port)
 135 {
 136         spin_lock(&port->port_update_lock);
 137         port->chan_enable = true;
 138         spin_unlock(&port->port_update_lock);
 139
 140         return 0;
 141 }
 142
 143 static int t7xx_port_wwan_disable_chl(struct t7xx_port *port)
 144 {
 145         spin_lock(&port->port_update_lock);
 146         port->chan_enable = false;
 147         spin_unlock(&port->port_update_lock);
 148
 149         return 0;
 150 }
 151
 152 static void t7xx_port_wwan_md_state_notify(struct t7xx_port *port, unsigned int state)
 153 {
 154         const struct t7xx_port_conf *port_conf = port->port_conf;
 155         unsigned int header_len = sizeof(struct ccci_header);
 156         struct wwan_port_caps caps;
 157
 158         if (state != MD_STATE_READY)
 159                 return;
 160
 161         if (!port->wwan.wwan_port) {
 162                 caps.frag_len = CLDMA_MTU - header_len;
 163                 caps.headroom_len = header_len;
 164                 port->wwan.wwan_port = wwan_create_port(port->dev, port_conf->port_type,
 165                                                         &wwan_ops, &caps, port);
 166                 if (IS_ERR(port->wwan.wwan_port))
 167                         dev_err(port->dev, "Unable to create WWWAN port %s", port_conf->name);
 168         }
 169 }
 170
 171 struct port_ops wwan_sub_port_ops = {
 172         .init = t7xx_port_wwan_init,
 173         .recv_skb = t7xx_port_wwan_recv_skb,
 174         .uninit = t7xx_port_wwan_uninit,
 175         .enable_chl = t7xx_port_wwan_enable_chl,
 176         .disable_chl = t7xx_port_wwan_disable_chl,
 177         .md_state_notify = t7xx_port_wwan_md_state_notify,
 178 };