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