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 #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 } __attribute__((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("MEI_PHY: Could not enable device\n"); 64 return r; 65 } 66 67 phy->powered = 1; 68 69 return 0; 70 } 71 EXPORT_SYMBOL_GPL(nfc_mei_phy_enable); 72 73 void nfc_mei_phy_disable(void *phy_id) 74 { 75 struct nfc_mei_phy *phy = phy_id; 76 77 pr_info("%s\n", __func__); 78 79 mei_cl_disable_device(phy->device); 80 81 phy->powered = 0; 82 } 83 EXPORT_SYMBOL_GPL(nfc_mei_phy_disable); 84 85 /* 86 * Writing a frame must not return the number of written bytes. 87 * It must return either zero for success, or <0 for error. 88 * In addition, it must not alter the skb 89 */ 90 static int nfc_mei_phy_write(void *phy_id, struct sk_buff *skb) 91 { 92 struct nfc_mei_phy *phy = phy_id; 93 int r; 94 95 MEI_DUMP_SKB_OUT("mei frame sent", skb); 96 97 r = mei_cl_send(phy->device, skb->data, skb->len); 98 if (r > 0) 99 r = 0; 100 101 return r; 102 } 103 104 void nfc_mei_event_cb(struct mei_cl_device *device, u32 events, void *context) 105 { 106 struct nfc_mei_phy *phy = context; 107 108 if (phy->hard_fault != 0) 109 return; 110 111 if (events & BIT(MEI_CL_EVENT_RX)) { 112 struct sk_buff *skb; 113 int reply_size; 114 115 skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL); 116 if (!skb) 117 return; 118 119 reply_size = mei_cl_recv(device, skb->data, MEI_NFC_MAX_READ); 120 if (reply_size < MEI_NFC_HEADER_SIZE) { 121 kfree(skb); 122 return; 123 } 124 125 skb_put(skb, reply_size); 126 skb_pull(skb, MEI_NFC_HEADER_SIZE); 127 128 MEI_DUMP_SKB_IN("mei frame read", skb); 129 130 nfc_hci_recv_frame(phy->hdev, skb); 131 } 132 } 133 EXPORT_SYMBOL_GPL(nfc_mei_event_cb); 134 135 struct nfc_phy_ops mei_phy_ops = { 136 .write = nfc_mei_phy_write, 137 .enable = nfc_mei_phy_enable, 138 .disable = nfc_mei_phy_disable, 139 }; 140 EXPORT_SYMBOL_GPL(mei_phy_ops); 141 142 struct nfc_mei_phy *nfc_mei_phy_alloc(struct mei_cl_device *device) 143 { 144 struct nfc_mei_phy *phy; 145 146 phy = kzalloc(sizeof(struct nfc_mei_phy), GFP_KERNEL); 147 if (!phy) 148 return NULL; 149 150 phy->device = device; 151 mei_cl_set_drvdata(device, phy); 152 153 return phy; 154 } 155 EXPORT_SYMBOL_GPL(nfc_mei_phy_alloc); 156 157 void nfc_mei_phy_free(struct nfc_mei_phy *phy) 158 { 159 kfree(phy); 160 } 161 EXPORT_SYMBOL_GPL(nfc_mei_phy_free); 162 163 MODULE_LICENSE("GPL"); 164 MODULE_DESCRIPTION("mei bus NFC device interface"); 165