diff options
Diffstat (limited to 'drivers/nfc/microread/mei.c')
| -rw-r--r-- | drivers/nfc/microread/mei.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/nfc/microread/mei.c b/drivers/nfc/microread/mei.c new file mode 100644 index 00000000000..eef38cfd812 --- /dev/null +++ b/drivers/nfc/microread/mei.c @@ -0,0 +1,246 @@ +/* + * HCI based Driver for Inside Secure microread NFC Chip + * + * Copyright (C) 2013 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/interrupt.h> +#include <linux/gpio.h> +#include <linux/mei_bus.h> + +#include <linux/nfc.h> +#include <net/nfc/hci.h> +#include <net/nfc/llc.h> + +#include "microread.h" + +#define MICROREAD_DRIVER_NAME "microread" + +#define MICROREAD_UUID UUID_LE(0x0bb17a78, 0x2a8e, 0x4c50, 0x94, \ + 0xd4, 0x50, 0x26, 0x67, 0x23, 0x77, 0x5c) + +struct mei_nfc_hdr { + u8 cmd; + u8 status; + u16 req_id; + u32 reserved; + u16 data_size; +} __attribute__((packed)); + +#define MEI_NFC_HEADER_SIZE 10 +#define MEI_NFC_MAX_HCI_PAYLOAD 300 +#define MEI_NFC_MAX_READ (MEI_NFC_HEADER_SIZE + MEI_NFC_MAX_HCI_PAYLOAD) + +struct microread_mei_phy { + struct mei_device *mei_device; + struct nfc_hci_dev *hdev; + + int powered; + + int hard_fault; /* + * < 0 if hardware error occured (e.g. i2c err) + * and prevents normal operation. + */ +}; + +#define MEI_DUMP_SKB_IN(info, skb) \ +do { \ + pr_debug("%s:\n", info); \ + print_hex_dump(KERN_DEBUG, "mei in : ", DUMP_PREFIX_OFFSET, \ + 16, 1, (skb)->data, (skb)->len, 0); \ +} while (0) + +#define MEI_DUMP_SKB_OUT(info, skb) \ +do { \ + pr_debug("%s:\n", info); \ + print_hex_dump(KERN_DEBUG, "mei out: ", DUMP_PREFIX_OFFSET, \ + 16, 1, (skb)->data, (skb)->len, 0); \ +} while (0) + +static int microread_mei_enable(void *phy_id) +{ + struct microread_mei_phy *phy = phy_id; + + pr_info(DRIVER_DESC ": %s\n", __func__); + + phy->powered = 1; + + return 0; +} + +static void microread_mei_disable(void *phy_id) +{ + struct microread_mei_phy *phy = phy_id; + + pr_info(DRIVER_DESC ": %s\n", __func__); + + phy->powered = 0; +} + +/* + * Writing a frame must not return the number of written bytes. + * It must return either zero for success, or <0 for error. + * In addition, it must not alter the skb + */ +static int microread_mei_write(void *phy_id, struct sk_buff *skb) +{ + struct microread_mei_phy *phy = phy_id; + int r; + + MEI_DUMP_SKB_OUT("mei frame sent", skb); + + r = mei_send(phy->device, skb->data, skb->len); + if (r > 0) + r = 0; + + return r; +} + +static void microread_event_cb(struct mei_device *device, u32 events, + void *context) +{ + struct microread_mei_phy *phy = context; + + if (phy->hard_fault != 0) + return; + + if (events & BIT(MEI_EVENT_RX)) { + struct sk_buff *skb; + int reply_size; + + skb = alloc_skb(MEI_NFC_MAX_READ, GFP_KERNEL); + if (!skb) + return; + + reply_size = mei_recv(device, skb->data, MEI_NFC_MAX_READ); + if (reply_size < MEI_NFC_HEADER_SIZE) { + kfree(skb); + return; + } + + skb_put(skb, reply_size); + skb_pull(skb, MEI_NFC_HEADER_SIZE); + + MEI_DUMP_SKB_IN("mei frame read", skb); + + nfc_hci_recv_frame(phy->hdev, skb); + } +} + +static struct nfc_phy_ops mei_phy_ops = { + .write = microread_mei_write, + .enable = microread_mei_enable, + .disable = microread_mei_disable, +}; + +static int microread_mei_probe(struct mei_device *device, + const struct mei_id *id) +{ + struct microread_mei_phy *phy; + int r; + + pr_info("Probing NFC microread\n"); + + phy = kzalloc(sizeof(struct microread_mei_phy), GFP_KERNEL); + if (!phy) { + pr_err("Cannot allocate memory for microread mei phy.\n"); + return -ENOMEM; + } + + phy->device = device; + mei_set_clientdata(device, phy); + + r = mei_register_event_cb(device, microread_event_cb, phy); + if (r) { + pr_err(MICROREAD_DRIVER_NAME ": event cb registration failed\n"); + goto err_out; + } + + r = microread_probe(phy, &mei_phy_ops, LLC_NOP_NAME, + MEI_NFC_HEADER_SIZE, 0, MEI_NFC_MAX_HCI_PAYLOAD, + &phy->hdev); + if (r < 0) + goto err_out; + + return 0; + +err_out: + kfree(phy); + + return r; +} + +static int microread_mei_remove(struct mei_device *device) +{ + struct microread_mei_phy *phy = mei_get_clientdata(device); + + pr_info("Removing microread\n"); + + microread_remove(phy->hdev); + + if (phy->powered) + microread_mei_disable(phy); + + kfree(phy); + + return 0; +} + +static struct mei_id microread_mei_tbl[] = { + { MICROREAD_DRIVER_NAME, MICROREAD_UUID }, + + /* required last entry */ + { } +}; + +MODULE_DEVICE_TABLE(mei, microread_mei_tbl); + +static struct mei_driver microread_driver = { + .id_table = microread_mei_tbl, + .name = MICROREAD_DRIVER_NAME, + + .probe = microread_mei_probe, + .remove = microread_mei_remove, +}; + +static int microread_mei_init(void) +{ + int r; + + pr_debug(DRIVER_DESC ": %s\n", __func__); + + r = mei_driver_register(µread_driver); + if (r) { + pr_err(MICROREAD_DRIVER_NAME ": driver registration failed\n"); + return r; + } + + return 0; +} + +static void microread_mei_exit(void) +{ + mei_driver_unregister(µread_driver); +} + +module_init(microread_mei_init); +module_exit(microread_mei_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION(DRIVER_DESC); |