1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2021, Stephan Gerhold <stephan@gerhold.net> */ 3 #include <linux/kernel.h> 4 #include <linux/mod_devicetable.h> 5 #include <linux/module.h> 6 #include <linux/platform_device.h> 7 #include <linux/rpmsg.h> 8 #include <linux/wwan.h> 9 10 struct rpmsg_wwan_dev { 11 /* Lower level is a rpmsg dev, upper level is a wwan port */ 12 struct rpmsg_device *rpdev; 13 struct wwan_port *wwan_port; 14 struct rpmsg_endpoint *ept; 15 }; 16 17 static int rpmsg_wwan_ctrl_callback(struct rpmsg_device *rpdev, 18 void *buf, int len, void *priv, u32 src) 19 { 20 struct rpmsg_wwan_dev *rpwwan = priv; 21 struct sk_buff *skb; 22 23 skb = alloc_skb(len, GFP_ATOMIC); 24 if (!skb) 25 return -ENOMEM; 26 27 skb_put_data(skb, buf, len); 28 wwan_port_rx(rpwwan->wwan_port, skb); 29 return 0; 30 } 31 32 static int rpmsg_wwan_ctrl_start(struct wwan_port *port) 33 { 34 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); 35 struct rpmsg_channel_info chinfo = { 36 .src = rpwwan->rpdev->src, 37 .dst = RPMSG_ADDR_ANY, 38 }; 39 40 strscpy(chinfo.name, rpwwan->rpdev->id.name, sizeof(chinfo.name)); 41 rpwwan->ept = rpmsg_create_ept(rpwwan->rpdev, rpmsg_wwan_ctrl_callback, 42 rpwwan, chinfo); 43 if (!rpwwan->ept) 44 return -EREMOTEIO; 45 46 return 0; 47 } 48 49 static void rpmsg_wwan_ctrl_stop(struct wwan_port *port) 50 { 51 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); 52 53 rpmsg_destroy_ept(rpwwan->ept); 54 rpwwan->ept = NULL; 55 } 56 57 static int rpmsg_wwan_ctrl_tx(struct wwan_port *port, struct sk_buff *skb) 58 { 59 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); 60 int ret; 61 62 ret = rpmsg_trysend(rpwwan->ept, skb->data, skb->len); 63 if (ret) 64 return ret; 65 66 consume_skb(skb); 67 return 0; 68 } 69 70 static int rpmsg_wwan_ctrl_tx_blocking(struct wwan_port *port, struct sk_buff *skb) 71 { 72 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); 73 int ret; 74 75 ret = rpmsg_send(rpwwan->ept, skb->data, skb->len); 76 if (ret) 77 return ret; 78 79 consume_skb(skb); 80 return 0; 81 } 82 83 static __poll_t rpmsg_wwan_ctrl_tx_poll(struct wwan_port *port, 84 struct file *filp, poll_table *wait) 85 { 86 struct rpmsg_wwan_dev *rpwwan = wwan_port_get_drvdata(port); 87 88 return rpmsg_poll(rpwwan->ept, filp, wait); 89 } 90 91 static const struct wwan_port_ops rpmsg_wwan_pops = { 92 .start = rpmsg_wwan_ctrl_start, 93 .stop = rpmsg_wwan_ctrl_stop, 94 .tx = rpmsg_wwan_ctrl_tx, 95 .tx_blocking = rpmsg_wwan_ctrl_tx_blocking, 96 .tx_poll = rpmsg_wwan_ctrl_tx_poll, 97 }; 98 99 static struct device *rpmsg_wwan_find_parent(struct device *dev) 100 { 101 /* Select first platform device as parent for the WWAN ports. 102 * On Qualcomm platforms this is usually the platform device that 103 * represents the modem remote processor. This might need to be 104 * adjusted when adding device IDs for other platforms. 105 */ 106 for (dev = dev->parent; dev; dev = dev->parent) { 107 if (dev_is_platform(dev)) 108 return dev; 109 } 110 return NULL; 111 } 112 113 static int rpmsg_wwan_ctrl_probe(struct rpmsg_device *rpdev) 114 { 115 struct rpmsg_wwan_dev *rpwwan; 116 struct wwan_port *port; 117 struct device *parent; 118 119 parent = rpmsg_wwan_find_parent(&rpdev->dev); 120 if (!parent) 121 return -ENODEV; 122 123 rpwwan = devm_kzalloc(&rpdev->dev, sizeof(*rpwwan), GFP_KERNEL); 124 if (!rpwwan) 125 return -ENOMEM; 126 127 rpwwan->rpdev = rpdev; 128 dev_set_drvdata(&rpdev->dev, rpwwan); 129 130 /* Register as a wwan port, id.driver_data contains wwan port type */ 131 port = wwan_create_port(parent, rpdev->id.driver_data, 132 &rpmsg_wwan_pops, NULL, rpwwan); 133 if (IS_ERR(port)) 134 return PTR_ERR(port); 135 136 rpwwan->wwan_port = port; 137 138 return 0; 139 }; 140 141 static void rpmsg_wwan_ctrl_remove(struct rpmsg_device *rpdev) 142 { 143 struct rpmsg_wwan_dev *rpwwan = dev_get_drvdata(&rpdev->dev); 144 145 wwan_remove_port(rpwwan->wwan_port); 146 } 147 148 static const struct rpmsg_device_id rpmsg_wwan_ctrl_id_table[] = { 149 /* RPMSG channels for Qualcomm SoCs with integrated modem */ 150 { .name = "DATA5_CNTL", .driver_data = WWAN_PORT_QMI }, 151 { .name = "DATA4", .driver_data = WWAN_PORT_AT }, 152 { .name = "DATA1", .driver_data = WWAN_PORT_AT }, 153 {}, 154 }; 155 MODULE_DEVICE_TABLE(rpmsg, rpmsg_wwan_ctrl_id_table); 156 157 static struct rpmsg_driver rpmsg_wwan_ctrl_driver = { 158 .drv.name = "rpmsg_wwan_ctrl", 159 .id_table = rpmsg_wwan_ctrl_id_table, 160 .probe = rpmsg_wwan_ctrl_probe, 161 .remove = rpmsg_wwan_ctrl_remove, 162 }; 163 module_rpmsg_driver(rpmsg_wwan_ctrl_driver); 164 165 MODULE_LICENSE("GPL v2"); 166 MODULE_DESCRIPTION("RPMSG WWAN CTRL Driver"); 167 MODULE_AUTHOR("Stephan Gerhold <stephan@gerhold.net>"); 168