1 /* 2 * MEI Library for mei bus nfc device access 3 * 4 * Copyright (C) 2013 Intel Corporation. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/module.h> 22 #include <linux/slab.h> 23 #include <linux/nfc.h> 24 25 #include "mei_phy.h" 26 27 struct mei_nfc_hdr { 28 u8 cmd; 29 u8 status; 30 u16 req_id; 31 u32 reserved; 32 u16 data_size; 33 } __packed; 34 35 #define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD) 36 37 #define MEI_DUMP_SKB_IN(info, skb) \ 38 do { \ 39 pr_debug("%s:\n", info); \ 40 print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET, \ 41 16, 1, (skb)->data, (skb)->len, false); \ 42 } while (0) 43 44 #define MEI_DUMP_SKB_OUT(info, skb) \ 45 do { \ 46 pr_debug("%s:\n", info); \ 47 print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET, \ 48 16, 1, (skb)->data, (skb)->len, false); \ 49 } while (0) 50 51 int nfc_mei_phy_enable(void *phy_id) 52 { 53 int r; 54 struct nfc_mei_phy *phy = phy_id; 55 56 pr_info("%s\n", __func__); 57 58 if (phy->powered == 1) 59 return 0; 60 61 r = mei_cl_enable_device(phy->device); 62 if (r < 0) { 63 pr_err("Could not enable device\n"); 64 return r; 65 } 66 67 r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy); 68 if (r) { 69 pr_err("Event cb registration failed\n"); 70 mei_cl_disable_device(phy->device); 71 phy->powered = 0; 72 73 return r; 74 } 75 76 phy->powered = 1; 77 78 return 0; 79 } 80 EXPORT_SYMBOL_GPL(nfc_mei_phy_enable); 81 82 void nfc_mei_phy_disable(void *phy_id) 83 { 84 struct nfc_mei_phy *phy = phy_id; 85 86 pr_info("%s\n", __func__); 87 88 mei_cl_disable_device(phy->device); 89 90 phy->powered = 0; 91 } 92 EXPORT_SYMBOL_GPL(nfc_mei_phy_disable); 93 94 /* 95 * Writing a frame must not return the number of written bytes. 96 * It must return either zero for success, or <0 for error. 97 * In addition, it must not alter the skb 98 */ 99 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb) 100 { 101 struct nfc_mei_phy *phy = phy_id; 102 int r; 103 104 MEI_DUMP_SKB_OUT("mei frame sent", skb); 105 106 r = mei_cl_send(phy->device, skb->data, skb->len); 107 if (r > 0) 108 r = 0; 109 110 return r; 111 } 112 113 void nfc_mei_event_cb(struct mei_cl_device *device, u32 events, void *context) 114 { 115 struct nfc_mei_phy *phy = context; 116 117 if (phy->hard_fault != 0) 118 return; 119 120 if (events & BIT(MEI_CL_EVENT_RX)) { 121 struct sk_buff *skb; 122 int reply_size; 123 124 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL); 125 if (!skb) 126 return; 127 128 reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ); 129 if (reply_size < MEI_NFC_HEADER_SIZE) { 130 kfree_skb(skb); 131 return; 132 } 133 134 skb_put(skb, reply_size); 135 skb_pull(skb, MEI_NFC_HEADER_SIZE); 136 137 MEI_DUMP_SKB_IN("mei frame read", skb); 138 139 nfc_hci_recv_frame(phy->hdev, skb); 140 } 141 } 142 EXPORT_SYMBOL_GPL(nfc_mei_event_cb); 143 144 struct nfc_phy_ops mei_phy_ops = { 145 .write = nfc_mei_phy_write, 146 .enable = nfc_mei_phy_enable, 147 .disable = nfc_mei_phy_disable, 148 }; 149 EXPORT_SYMBOL_GPL(mei_phy_ops); 150 151 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device) 152 { 153 struct nfc_mei_phy *phy; 154 155 phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL); 156 if (!phy) 157 return NULL; 158 159 phy->device = device; 160 mei_cl_set_drvdata(device, phy); 161 162 return phy; 163 } 164 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc); 165 166 void nfc_mei_phy_free(struct nfc_mei_phy *phy) 167 { 168 kfree(phy); 169 } 170 EXPORT_SYMBOL_GPL(nfc_mei_phy_free); 171 172 MODULE_LICENSE("GPL"); 173 MODULE_DESCRIPTION("mei bus NFC device interface"); 174