1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * NFC Digital Protocol stack
4  * Copyright (c) 2013, Intel Corporation.
5  */
6 
7 #ifndef __NFC_DIGITAL_H
8 #define __NFC_DIGITAL_H
9 
10 #include <linux/skbuff.h>
11 #include <net/nfc/nfc.h>
12 
13 /**
14  * Configuration types for in_configure_hw and tg_configure_hw.
15  */
16 enum {
17 	NFC_DIGITAL_CONFIG_RF_TECH = 0,
18 	NFC_DIGITAL_CONFIG_FRAMING,
19 };
20 
21 /**
22  * RF technology values passed as param argument to in_configure_hw and
23  * tg_configure_hw for NFC_DIGITAL_CONFIG_RF_TECH configuration type.
24  */
25 enum {
26 	NFC_DIGITAL_RF_TECH_106A = 0,
27 	NFC_DIGITAL_RF_TECH_212F,
28 	NFC_DIGITAL_RF_TECH_424F,
29 	NFC_DIGITAL_RF_TECH_ISO15693,
30 	NFC_DIGITAL_RF_TECH_106B,
31 
32 	NFC_DIGITAL_RF_TECH_LAST,
33 };
34 
35 /**
36  * Framing configuration passed as param argument to in_configure_hw and
37  * tg_configure_hw for NFC_DIGITAL_CONFIG_FRAMING configuration type.
38  */
39 enum {
40 	NFC_DIGITAL_FRAMING_NFCA_SHORT = 0,
41 	NFC_DIGITAL_FRAMING_NFCA_STANDARD,
42 	NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A,
43 	NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE,
44 
45 	NFC_DIGITAL_FRAMING_NFCA_T1T,
46 	NFC_DIGITAL_FRAMING_NFCA_T2T,
47 	NFC_DIGITAL_FRAMING_NFCA_T4T,
48 	NFC_DIGITAL_FRAMING_NFCA_NFC_DEP,
49 
50 	NFC_DIGITAL_FRAMING_NFCF,
51 	NFC_DIGITAL_FRAMING_NFCF_T3T,
52 	NFC_DIGITAL_FRAMING_NFCF_NFC_DEP,
53 	NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED,
54 
55 	NFC_DIGITAL_FRAMING_ISO15693_INVENTORY,
56 	NFC_DIGITAL_FRAMING_ISO15693_T5T,
57 
58 	NFC_DIGITAL_FRAMING_NFCB,
59 	NFC_DIGITAL_FRAMING_NFCB_T4T,
60 
61 	NFC_DIGITAL_FRAMING_LAST,
62 };
63 
64 #define DIGITAL_MDAA_NFCID1_SIZE 3
65 
66 struct digital_tg_mdaa_params {
67 	u16 sens_res;
68 	u8 nfcid1[DIGITAL_MDAA_NFCID1_SIZE];
69 	u8 sel_res;
70 
71 	u8 nfcid2[NFC_NFCID2_MAXSIZE];
72 	u16 sc;
73 };
74 
75 struct nfc_digital_dev;
76 
77 /**
78  * nfc_digital_cmd_complete_t - Definition of command result callback
79  *
80  * @ddev: nfc_digital_device ref
81  * @arg: user data
82  * @resp: response data
83  *
84  * resp pointer can be an error code and will be checked with IS_ERR() macro.
85  * The callback is responsible for freeing resp sk_buff.
86  */
87 typedef void (*nfc_digital_cmd_complete_t)(struct nfc_digital_dev *ddev,
88 					   void *arg, struct sk_buff *resp);
89 
90 /**
91  * Device side NFC Digital operations
92  *
93  * Initiator mode:
94  * @in_configure_hw: Hardware configuration for RF technology and communication
95  *	framing in initiator mode. This is a synchronous function.
96  * @in_send_cmd: Initiator mode data exchange using RF technology and framing
97  *	previously set with in_configure_hw. The peer response is returned
98  *	through callback cb. If an io error occurs or the peer didn't reply
99  *	within the specified timeout (ms), the error code is passed back through
100  *	the resp pointer. This is an asynchronous function.
101  *
102  * Target mode: Only NFC-DEP protocol is supported in target mode.
103  * @tg_configure_hw: Hardware configuration for RF technology and communication
104  *	framing in target mode. This is a synchronous function.
105  * @tg_send_cmd: Target mode data exchange using RF technology and framing
106  *	previously set with tg_configure_hw. The peer next command is returned
107  *	through callback cb. If an io error occurs or the peer didn't reply
108  *	within the specified timeout (ms), the error code is passed back through
109  *	the resp pointer. This is an asynchronous function.
110  * @tg_listen: Put the device in listen mode waiting for data from the peer
111  *	device. This is an asynchronous function.
112  * @tg_listen_mdaa: If supported, put the device in automatic listen mode with
113  *	mode detection and automatic anti-collision. In this mode, the device
114  *	automatically detects the RF technology and executes the anti-collision
115  *	detection using the command responses specified in mdaa_params. The
116  *	mdaa_params structure contains SENS_RES, NFCID1, and SEL_RES for 106A RF
117  *	tech. NFCID2 and system code (sc) for 212F and 424F. The driver returns
118  *	the NFC-DEP ATR_REQ command through cb. The digital stack deducts the RF
119  *	tech by analyzing the SoD of the frame containing the ATR_REQ command.
120  *	This is an asynchronous function.
121  * @tg_listen_md: If supported, put the device in automatic listen mode with
122  *	mode detection but without automatic anti-collision. In this mode, the
123  *	device automatically detects the RF technology.  What the actual
124  *	RF technology is can be retrieved by calling @tg_get_rf_tech.
125  *	The digital stack will then perform the appropriate anti-collision
126  *	sequence.  This is an asynchronous function.
127  * @tg_get_rf_tech: Required when @tg_listen_md is supported, unused otherwise.
128  *	Return the RF Technology that was detected by the @tg_listen_md call.
129  *	This is a synchronous function.
130  *
131  * @switch_rf: Turns device radio on or off. The stack does not call explicitly
132  *	switch_rf to turn the radio on. A call to in|tg_configure_hw must turn
133  *	the device radio on.
134  * @abort_cmd: Discard the last sent command.
135  *
136  * Notes: Asynchronous functions have a timeout parameter. It is the driver
137  *	responsibility to call the digital stack back through the
138  *	nfc_digital_cmd_complete_t callback when no RF respsonse has been
139  *	received within the specified time (in milliseconds). In that case the
140  *	driver must set the resp sk_buff to ERR_PTR(-ETIMEDOUT).
141  *	Since the digital stack serializes commands to be sent, it's mandatory
142  *	for the driver to handle the timeout correctly. Otherwise the stack
143  *	would not be able to send new commands, waiting for the reply of the
144  *	current one.
145  */
146 struct nfc_digital_ops {
147 	int (*in_configure_hw)(struct nfc_digital_dev *ddev, int type,
148 			       int param);
149 	int (*in_send_cmd)(struct nfc_digital_dev *ddev, struct sk_buff *skb,
150 			   u16 timeout, nfc_digital_cmd_complete_t cb,
151 			   void *arg);
152 
153 	int (*tg_configure_hw)(struct nfc_digital_dev *ddev, int type,
154 			       int param);
155 	int (*tg_send_cmd)(struct nfc_digital_dev *ddev, struct sk_buff *skb,
156 			   u16 timeout, nfc_digital_cmd_complete_t cb,
157 			   void *arg);
158 	int (*tg_listen)(struct nfc_digital_dev *ddev, u16 timeout,
159 			 nfc_digital_cmd_complete_t cb, void *arg);
160 	int (*tg_listen_mdaa)(struct nfc_digital_dev *ddev,
161 			      struct digital_tg_mdaa_params *mdaa_params,
162 			      u16 timeout, nfc_digital_cmd_complete_t cb,
163 			      void *arg);
164 	int (*tg_listen_md)(struct nfc_digital_dev *ddev, u16 timeout,
165 			    nfc_digital_cmd_complete_t cb, void *arg);
166 	int (*tg_get_rf_tech)(struct nfc_digital_dev *ddev, u8 *rf_tech);
167 
168 	int (*switch_rf)(struct nfc_digital_dev *ddev, bool on);
169 	void (*abort_cmd)(struct nfc_digital_dev *ddev);
170 };
171 
172 #define NFC_DIGITAL_POLL_MODE_COUNT_MAX	6 /* 106A, 212F, and 424F in & tg */
173 
174 typedef int (*digital_poll_t)(struct nfc_digital_dev *ddev, u8 rf_tech);
175 
176 struct digital_poll_tech {
177 	u8 rf_tech;
178 	digital_poll_t poll_func;
179 };
180 
181 /**
182  * Driver capabilities - bit mask made of the following values
183  *
184  * @NFC_DIGITAL_DRV_CAPS_IN_CRC: The driver handles CRC calculation in initiator
185  *	mode.
186  * @NFC_DIGITAL_DRV_CAPS_TG_CRC: The driver handles CRC calculation in target
187  *	mode.
188  */
189 #define NFC_DIGITAL_DRV_CAPS_IN_CRC	0x0001
190 #define NFC_DIGITAL_DRV_CAPS_TG_CRC	0x0002
191 
192 struct nfc_digital_dev {
193 	struct nfc_dev *nfc_dev;
194 	const struct nfc_digital_ops *ops;
195 
196 	u32 protocols;
197 
198 	int tx_headroom;
199 	int tx_tailroom;
200 
201 	u32 driver_capabilities;
202 	void *driver_data;
203 
204 	struct digital_poll_tech poll_techs[NFC_DIGITAL_POLL_MODE_COUNT_MAX];
205 	u8 poll_tech_count;
206 	u8 poll_tech_index;
207 	struct mutex poll_lock;
208 
209 	struct work_struct cmd_work;
210 	struct work_struct cmd_complete_work;
211 	struct list_head cmd_queue;
212 	struct mutex cmd_lock;
213 
214 	struct delayed_work poll_work;
215 
216 	u8 curr_protocol;
217 	u8 curr_rf_tech;
218 	u8 curr_nfc_dep_pni;
219 	u8 did;
220 	u16 dep_rwt;
221 
222 	u8 local_payload_max;
223 	u8 remote_payload_max;
224 
225 	struct sk_buff *chaining_skb;
226 	struct digital_data_exch *data_exch;
227 
228 	int atn_count;
229 	int nack_count;
230 
231 	struct sk_buff *saved_skb;
232 
233 	u16 target_fsc;
234 
235 	int (*skb_check_crc)(struct sk_buff *skb);
236 	void (*skb_add_crc)(struct sk_buff *skb);
237 };
238 
239 struct nfc_digital_dev *nfc_digital_allocate_device(const struct nfc_digital_ops *ops,
240 						    __u32 supported_protocols,
241 						    __u32 driver_capabilities,
242 						    int tx_headroom,
243 						    int tx_tailroom);
244 void nfc_digital_free_device(struct nfc_digital_dev *ndev);
245 int nfc_digital_register_device(struct nfc_digital_dev *ndev);
246 void nfc_digital_unregister_device(struct nfc_digital_dev *ndev);
247 
nfc_digital_set_parent_dev(struct nfc_digital_dev * ndev,struct device * dev)248 static inline void nfc_digital_set_parent_dev(struct nfc_digital_dev *ndev,
249 					      struct device *dev)
250 {
251 	nfc_set_parent_dev(ndev->nfc_dev, dev);
252 }
253 
nfc_digital_set_drvdata(struct nfc_digital_dev * dev,void * data)254 static inline void nfc_digital_set_drvdata(struct nfc_digital_dev *dev,
255 					   void *data)
256 {
257 	dev->driver_data = data;
258 }
259 
nfc_digital_get_drvdata(struct nfc_digital_dev * dev)260 static inline void *nfc_digital_get_drvdata(struct nfc_digital_dev *dev)
261 {
262 	return dev->driver_data;
263 }
264 
265 #endif /* __NFC_DIGITAL_H */
266