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, write to the 17 * Free Software Foundation, Inc., 18 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 19 */ 20 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/module.h> 24 #include <linux/slab.h> 25 #include <linux/nfc.h> 26 27 #include "mei_phy.h" 28 29 struct mei_nfc_hdr { 30 u8 cmd; 31 u8 status; 32 u16 req_id; 33 u32 reserved; 34 u16 data_size; 35 } __packed; 36 37 #define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD) 38 39 #define MEI_DUMP_SKB_IN(info, skb) \ 40 do { \ 41 pr_debug("%s:\n", info); \ 42 print_hex_dump_debug("mei in : ", DUMP_PREFIX_OFFSET, \ 43 16, 1, (skb)->data, (skb)->len, false); \ 44 } while (0) 45 46 #define MEI_DUMP_SKB_OUT(info, skb) \ 47 do { \ 48 pr_debug("%s:\n", info); \ 49 print_hex_dump_debug("mei out: ", DUMP_PREFIX_OFFSET, \ 50 16, 1, (skb)->data, (skb)->len, false); \ 51 } while (0) 52 53 int nfc_mei_phy_enable(void *phy_id) 54 { 55 int r; 56 struct nfc_mei_phy *phy = phy_id; 57 58 pr_info("%s\n", __func__); 59 60 if (phy->powered == 1) 61 return 0; 62 63 r = mei_cl_enable_device(phy->device); 64 if (r < 0) { 65 pr_err("Could not enable device\n"); 66 return r; 67 } 68 69 r = mei_cl_register_event_cb(phy->device, nfc_mei_event_cb, phy); 70 if (r) { 71 pr_err("Event cb registration failed\n"); 72 mei_cl_disable_device(phy->device); 73 phy->powered = 0; 74 75 return r; 76 } 77 78 phy->powered = 1; 79 80 return 0; 81 } 82 EXPORT_SYMBOL_GPL(nfc_mei_phy_enable); 83 84 void nfc_mei_phy_disable(void *phy_id) 85 { 86 struct nfc_mei_phy *phy = phy_id; 87 88 pr_info("%s\n", __func__); 89 90 mei_cl_disable_device(phy->device); 91 92 phy->powered = 0; 93 } 94 EXPORT_SYMBOL_GPL(nfc_mei_phy_disable); 95 96 /* 97 * Writing a frame must not return the number of written bytes. 98 * It must return either zero for success, or <0 for error. 99 * In addition, it must not alter the skb 100 */ 101 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb) 102 { 103 struct nfc_mei_phy *phy = phy_id; 104 int r; 105 106 MEI_DUMP_SKB_OUT("mei frame sent", skb); 107 108 r = mei_cl_send(phy->device, skb->data, skb->len); 109 if (r > 0) 110 r = 0; 111 112 return r; 113 } 114 115 void nfc_mei_event_cb(struct mei_cl_device *device, u32 events, void *context) 116 { 117 struct nfc_mei_phy *phy = context; 118 119 if (phy->hard_fault != 0) 120 return; 121 122 if (events & BIT(MEI_CL_EVENT_RX)) { 123 struct sk_buff *skb; 124 int reply_size; 125 126 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL); 127 if (!skb) 128 return; 129 130 reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ); 131 if (reply_size < MEI_NFC_HEADER_SIZE) { 132 kfree(skb); 133 return; 134 } 135 136 skb_put(skb, reply_size); 137 skb_pull(skb, MEI_NFC_HEADER_SIZE); 138 139 MEI_DUMP_SKB_IN("mei frame read", skb); 140 141 nfc_hci_recv_frame(phy->hdev, skb); 142 } 143 } 144 EXPORT_SYMBOL_GPL(nfc_mei_event_cb); 145 146 struct nfc_phy_ops mei_phy_ops = { 147 .write = nfc_mei_phy_write, 148 .enable = nfc_mei_phy_enable, 149 .disable = nfc_mei_phy_disable, 150 }; 151 EXPORT_SYMBOL_GPL(mei_phy_ops); 152 153 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device) 154 { 155 struct nfc_mei_phy *phy; 156 157 phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL); 158 if (!phy) 159 return NULL; 160 161 phy->device = device; 162 mei_cl_set_drvdata(device, phy); 163 164 return phy; 165 } 166 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc); 167 168 void nfc_mei_phy_free(struct nfc_mei_phy *phy) 169 { 170 kfree(phy); 171 } 172 EXPORT_SYMBOL_GPL(nfc_mei_phy_free); 173 174 MODULE_LICENSE("GPL"); 175 MODULE_DESCRIPTION("mei bus NFC device interface"); 176