xref: /linux/drivers/nfc/trf7970a.c (revision d34e48d6a62a06eb7f72c7dc534c4c318a163dad)
1 /*
2  * TI TRF7970a RFID/NFC Transceiver Driver
3  *
4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Author: Erick Macias <emacias@ti.com>
7  * Author: Felipe Balbi <balbi@ti.com>
8  * Author: Mark A. Greer <mgreer@animalcreek.com>
9  *
10  * This program is free software: you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2  of
12  * the License as published by the Free Software Foundation.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/netdevice.h>
18 #include <linux/interrupt.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/nfc.h>
21 #include <linux/skbuff.h>
22 #include <linux/delay.h>
23 #include <linux/gpio/consumer.h>
24 #include <linux/of.h>
25 #include <linux/spi/spi.h>
26 #include <linux/regulator/consumer.h>
27 
28 #include <net/nfc/nfc.h>
29 #include <net/nfc/digital.h>
30 
31 /* There are 3 ways the host can communicate with the trf7970a:
32  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
33  * SS mode.  The driver only supports the two SPI modes.
34  *
35  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
36  * pins must asserted in that order and with specific delays in between.
37  * The delays used in the driver were provided by TI and have been
38  * confirmed to work with this driver.  There is a bug with the current
39  * version of the trf7970a that requires that EN2 remain low no matter
40  * what.  If it goes high, it will generate an RF field even when in
41  * passive target mode.  TI has indicated that the chip will work okay
42  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
43  * indicates that trf7970a currently being used has the erratum and
44  * that EN2 must be kept low.
45  *
46  * Timeouts are implemented using the delayed workqueue kernel facility.
47  * Timeouts are required so things don't hang when there is no response
48  * from the trf7970a (or tag).  Using this mechanism creates a race with
49  * interrupts, however.  That is, an interrupt and a timeout could occur
50  * closely enough together that one is blocked by the mutex while the other
51  * executes.  When the timeout handler executes first and blocks the
52  * interrupt handler, it will eventually set the state to IDLE so the
53  * interrupt handler will check the state and exit with no harm done.
54  * When the interrupt handler executes first and blocks the timeout handler,
55  * the cancel_delayed_work() call will know that it didn't cancel the
56  * work item (i.e., timeout) and will return zero.  That return code is
57  * used by the timer handler to indicate that it should ignore the timeout
58  * once its unblocked.
59  *
60  * Aborting an active command isn't as simple as it seems because the only
61  * way to abort a command that's already been sent to the tag is so turn
62  * off power to the tag.  If we do that, though, we'd have to go through
63  * the entire anticollision procedure again but the digital layer doesn't
64  * support that.  So, if an abort is received before trf7970a_send_cmd()
65  * has sent the command to the tag, it simply returns -ECANCELED.  If the
66  * command has already been sent to the tag, then the driver continues
67  * normally and recieves the response data (or error) but just before
68  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
69  * upstream instead.  If the command failed, that error will be sent
70  * upstream.
71  *
72  * When recieving data from a tag and the interrupt status register has
73  * only the SRX bit set, it means that all of the data has been received
74  * (once what's in the fifo has been read).  However, depending on timing
75  * an interrupt status with only the SRX bit set may not be recived.  In
76  * those cases, the timeout mechanism is used to wait 20 ms in case more
77  * data arrives.  After 20 ms, it is assumed that all of the data has been
78  * received and the accumulated rx data is sent upstream.  The
79  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
80  * (i.e., it indicates that some data has been received but we're not sure
81  * if there is more coming so a timeout in this state means all data has
82  * been received and there isn't an error).  The delay is 20 ms since delays
83  * of ~16 ms have been observed during testing.
84  *
85  * When transmitting a frame larger than the FIFO size (127 bytes), the
86  * driver will wait 20 ms for the FIFO to drain past the low-watermark
87  * and generate an interrupt.  The low-watermark set to 32 bytes so the
88  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
89  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
90  * to ~14.35 ms so 20 ms is used for the timeout.
91  *
92  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
93  * Having only 4 bits in the FIFO won't normally generate an interrupt so
94  * driver enables the '4_bit_RX' bit of the Special Functions register 1
95  * to cause an interrupt in that case.  Leaving that bit for a read command
96  * messes up the data returned so it is only enabled when the framing is
97  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
98  * Unfortunately, that means that the driver has to peek into tx frames
99  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
100  * the trf7970a_per_cmd_config() routine.
101  *
102  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
103  * frequencies and whether to use low or high data rates in the flags byte
104  * of the frame.  This means that the driver has to peek at all 15693 frames
105  * to determine what speed to set the communication to.  In addition, write
106  * and lock commands use the OPTION flag to indicate that an EOF must be
107  * sent to the tag before it will send its response.  So the driver has to
108  * examine all frames for that reason too.
109  *
110  * It is unclear how long to wait before sending the EOF.  According to the
111  * Note under Table 1-1 in section 1.6 of
112  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
113  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
114  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
115  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
116  * ensure the wait is long enough before sending the EOF.  This seems to work
117  * reliably.
118  */
119 
120 #define TRF7970A_SUPPORTED_PROTOCOLS \
121 		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\
122 		 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
123 		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
124 
125 #define TRF7970A_AUTOSUSPEND_DELAY		30000 /* 30 seconds */
126 #define TRF7970A_13MHZ_CLOCK_FREQUENCY		13560000
127 #define TRF7970A_27MHZ_CLOCK_FREQUENCY		27120000
128 
129 
130 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
131 
132 #define TRF7970A_FIFO_SIZE			127
133 
134 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
135 #define TRF7970A_TX_MAX				(4096 - 1)
136 
137 #define TRF7970A_WAIT_FOR_TX_IRQ		20
138 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
139 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
140 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
141 
142 /* Guard times for various RF technologies (in us) */
143 #define TRF7970A_GUARD_TIME_NFCA		5000
144 #define TRF7970A_GUARD_TIME_NFCB		5000
145 #define TRF7970A_GUARD_TIME_NFCF		20000
146 #define TRF7970A_GUARD_TIME_15693		1000
147 
148 /* Quirks */
149 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
150  * read continuous command for IRQ Status and Collision Position registers.
151  */
152 #define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
153 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
154 #define TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE	BIT(2)
155 
156 /* Direct commands */
157 #define TRF7970A_CMD_IDLE			0x00
158 #define TRF7970A_CMD_SOFT_INIT			0x03
159 #define TRF7970A_CMD_RF_COLLISION		0x04
160 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
161 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
162 #define TRF7970A_CMD_FIFO_RESET			0x0f
163 #define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
164 #define TRF7970A_CMD_TRANSMIT			0x11
165 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
166 #define TRF7970A_CMD_DELAY_TRANSMIT		0x13
167 #define TRF7970A_CMD_EOF			0x14
168 #define TRF7970A_CMD_CLOSE_SLOT			0x15
169 #define TRF7970A_CMD_BLOCK_RX			0x16
170 #define TRF7970A_CMD_ENABLE_RX			0x17
171 #define TRF7970A_CMD_TEST_INT_RF		0x18
172 #define TRF7970A_CMD_TEST_EXT_RF		0x19
173 #define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
174 
175 /* Bits determining whether its a direct command or register R/W,
176  * whether to use a continuous SPI transaction or not, and the actual
177  * direct cmd opcode or regster address.
178  */
179 #define TRF7970A_CMD_BIT_CTRL			BIT(7)
180 #define TRF7970A_CMD_BIT_RW			BIT(6)
181 #define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
182 #define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
183 
184 /* Registers addresses */
185 #define TRF7970A_CHIP_STATUS_CTRL		0x00
186 #define TRF7970A_ISO_CTRL			0x01
187 #define TRF7970A_ISO14443B_TX_OPTIONS		0x02
188 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
189 #define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
190 #define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
191 #define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
192 #define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
193 #define TRF7970A_RX_WAIT_TIME			0x08
194 #define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
195 #define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
196 #define TRF7970A_REG_IO_CTRL			0x0b
197 #define TRF7970A_IRQ_STATUS			0x0c
198 #define TRF7970A_COLLISION_IRQ_MASK		0x0d
199 #define TRF7970A_COLLISION_POSITION		0x0e
200 #define TRF7970A_RSSI_OSC_STATUS		0x0f
201 #define TRF7970A_SPECIAL_FCN_REG1		0x10
202 #define TRF7970A_SPECIAL_FCN_REG2		0x11
203 #define TRF7970A_RAM1				0x12
204 #define TRF7970A_RAM2				0x13
205 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
206 #define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
207 #define TRF7970A_NFCID1				0x17
208 #define TRF7970A_NFC_TARGET_LEVEL		0x18
209 #define TRF79070A_NFC_TARGET_PROTOCOL		0x19
210 #define TRF7970A_TEST_REGISTER1			0x1a
211 #define TRF7970A_TEST_REGISTER2			0x1b
212 #define TRF7970A_FIFO_STATUS			0x1c
213 #define TRF7970A_TX_LENGTH_BYTE1		0x1d
214 #define TRF7970A_TX_LENGTH_BYTE2		0x1e
215 #define TRF7970A_FIFO_IO_REGISTER		0x1f
216 
217 /* Chip Status Control Register Bits */
218 #define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
219 #define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
220 #define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
221 #define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
222 #define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
223 #define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
224 #define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
225 #define TRF7970A_CHIP_STATUS_STBY		BIT(7)
226 
227 /* ISO Control Register Bits */
228 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
230 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
231 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
232 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
234 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
235 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
236 #define TRF7970A_ISO_CTRL_14443A_106		0x08
237 #define TRF7970A_ISO_CTRL_14443A_212		0x09
238 #define TRF7970A_ISO_CTRL_14443A_424		0x0a
239 #define TRF7970A_ISO_CTRL_14443A_848		0x0b
240 #define TRF7970A_ISO_CTRL_14443B_106		0x0c
241 #define TRF7970A_ISO_CTRL_14443B_212		0x0d
242 #define TRF7970A_ISO_CTRL_14443B_424		0x0e
243 #define TRF7970A_ISO_CTRL_14443B_848		0x0f
244 #define TRF7970A_ISO_CTRL_FELICA_212		0x1a
245 #define TRF7970A_ISO_CTRL_FELICA_424		0x1b
246 #define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
247 #define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
248 #define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
249 #define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
250 #define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
251 #define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
252 #define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
253 #define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
254 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
255 #define TRF7970A_ISO_CTRL_RFID			BIT(5)
256 #define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
257 #define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
258 
259 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
260 
261 /* Modulator and SYS_CLK Control Register Bits */
262 #define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
263 #define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
264 #define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
265 #define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
266 #define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
267 #define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
268 #define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
269 #define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
270 #define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
271 #define TRF7970A_MODULATOR_EN_ANA		BIT(3)
272 #define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
273 #define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
274 #define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
275 #define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
276 #define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
277 #define TRF7970A_MODULATOR_EN_OOK		BIT(6)
278 #define TRF7970A_MODULATOR_27MHZ		BIT(7)
279 
280 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
281 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
282 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
285 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
286 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
287 #define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
288 #define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
289 #define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
290 
291 #define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
292 #define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
293 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
294 #define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
295 
296 /* IRQ Status Register Bits */
297 #define TRF7970A_IRQ_STATUS_NORESP		BIT(0) /* ISO15693 only */
298 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
299 #define TRF7970A_IRQ_STATUS_COL			BIT(1)
300 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
301 #define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
302 #define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
303 #define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
304 #define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
305 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
306 #define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
307 #define TRF7970A_IRQ_STATUS_SRX			BIT(6)
308 #define TRF7970A_IRQ_STATUS_TX			BIT(7)
309 
310 #define TRF7970A_IRQ_STATUS_ERROR				\
311 		(TRF7970A_IRQ_STATUS_COL |			\
312 		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
313 		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
314 		 TRF7970A_IRQ_STATUS_CRC_ERROR)
315 
316 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
317 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
318 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
319 
320 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
321 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
322 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
323 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
324 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
325 #define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
326 
327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
333 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
334 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
335 
336 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
337 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
338 
339 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
340 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
341 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
342 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
343 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
344 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
345 
346 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
347 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
349 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
350 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
351 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
352 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
353 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
354 
355 #define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
356 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
357 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
358 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
359 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
360 
361 #define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
362 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
363 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
364 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
365 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
366 
367 #define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
368 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
369 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
370 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
371 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
372 
373 #define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
374 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
375 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
376 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
377 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
378 
379 #define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
380 
381 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
382 #define NFC_T2T_CMD_READ			0x30
383 
384 /* ISO 15693 commands codes */
385 #define ISO15693_CMD_INVENTORY			0x01
386 #define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
387 #define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
388 #define ISO15693_CMD_LOCK_BLOCK			0x22
389 #define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
390 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
391 #define ISO15693_CMD_SELECT			0x25
392 #define ISO15693_CMD_RESET_TO_READY		0x26
393 #define ISO15693_CMD_WRITE_AFI			0x27
394 #define ISO15693_CMD_LOCK_AFI			0x28
395 #define ISO15693_CMD_WRITE_DSFID		0x29
396 #define ISO15693_CMD_LOCK_DSFID			0x2a
397 #define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
398 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
399 
400 /* ISO 15693 request and response flags */
401 #define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
402 #define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
403 #define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
404 #define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
405 #define ISO15693_REQ_FLAG_SELECT		BIT(4)
406 #define ISO15693_REQ_FLAG_AFI			BIT(4)
407 #define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
408 #define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
409 #define ISO15693_REQ_FLAG_OPTION		BIT(6)
410 
411 #define ISO15693_REQ_FLAG_SPEED_MASK \
412 		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
413 
414 enum trf7970a_state {
415 	TRF7970A_ST_PWR_OFF,
416 	TRF7970A_ST_RF_OFF,
417 	TRF7970A_ST_IDLE,
418 	TRF7970A_ST_IDLE_RX_BLOCKED,
419 	TRF7970A_ST_WAIT_FOR_TX_FIFO,
420 	TRF7970A_ST_WAIT_FOR_RX_DATA,
421 	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
422 	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
423 	TRF7970A_ST_LISTENING,
424 	TRF7970A_ST_LISTENING_MD,
425 	TRF7970A_ST_MAX
426 };
427 
428 struct trf7970a {
429 	enum trf7970a_state		state;
430 	struct device			*dev;
431 	struct spi_device		*spi;
432 	struct regulator		*regulator;
433 	struct nfc_digital_dev		*ddev;
434 	u32				quirks;
435 	bool				is_initiator;
436 	bool				aborting;
437 	struct sk_buff			*tx_skb;
438 	struct sk_buff			*rx_skb;
439 	nfc_digital_cmd_complete_t	cb;
440 	void				*cb_arg;
441 	u8				chip_status_ctrl;
442 	u8				iso_ctrl;
443 	u8				iso_ctrl_tech;
444 	u8				modulator_sys_clk_ctrl;
445 	u8				special_fcn_reg1;
446 	u8				io_ctrl;
447 	unsigned int			guard_time;
448 	int				technology;
449 	int				framing;
450 	u8				md_rf_tech;
451 	u8				tx_cmd;
452 	bool				issue_eof;
453 	bool				adjust_resp_len;
454 	struct gpio_desc		*en_gpiod;
455 	struct gpio_desc		*en2_gpiod;
456 	struct mutex			lock;
457 	unsigned int			timeout;
458 	bool				ignore_timeout;
459 	struct delayed_work		timeout_work;
460 };
461 
462 
463 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
464 {
465 	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
466 	int ret;
467 
468 	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
469 
470 	ret = spi_write(trf->spi, &cmd, 1);
471 	if (ret)
472 		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
473 				ret);
474 	return ret;
475 }
476 
477 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
478 {
479 	u8 addr = TRF7970A_CMD_BIT_RW | reg;
480 	int ret;
481 
482 	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
483 	if (ret)
484 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
485 				ret);
486 
487 	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
488 
489 	return ret;
490 }
491 
492 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, size_t len)
493 {
494 	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
495 	struct spi_transfer t[2];
496 	struct spi_message m;
497 	int ret;
498 
499 	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
500 
501 	spi_message_init(&m);
502 
503 	memset(&t, 0, sizeof(t));
504 
505 	t[0].tx_buf = &addr;
506 	t[0].len = sizeof(addr);
507 	spi_message_add_tail(&t[0], &m);
508 
509 	t[1].rx_buf = buf;
510 	t[1].len = len;
511 	spi_message_add_tail(&t[1], &m);
512 
513 	ret = spi_sync(trf->spi, &m);
514 	if (ret)
515 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
516 				ret);
517 	return ret;
518 }
519 
520 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
521 {
522 	u8 buf[2] = { reg, val };
523 	int ret;
524 
525 	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
526 
527 	ret = spi_write(trf->spi, buf, 2);
528 	if (ret)
529 		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
530 				buf[0], buf[1], ret);
531 
532 	return ret;
533 }
534 
535 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
536 {
537 	int ret;
538 	u8 buf[2];
539 	u8 addr;
540 
541 	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
542 
543 	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
544 		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
545 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
546 	} else {
547 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
548 	}
549 
550 	if (ret)
551 		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
552 				__func__, ret);
553 	else
554 		*status = buf[0];
555 
556 	return ret;
557 }
558 
559 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
560 {
561 	int ret;
562 	u8 buf[2];
563 	u8 addr;
564 
565 	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
566 		TRF7970A_CMD_BIT_CONTINUOUS;
567 
568 	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
569 	if (ret)
570 		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
571 				__func__, ret);
572 	else
573 		*target_proto = buf[0];
574 
575 	return ret;
576 }
577 
578 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
579 {
580 	int ret;
581 	u8 target_proto, tech;
582 
583 	ret = trf7970a_read_target_proto(trf, &target_proto);
584 	if (ret)
585 		return ret;
586 
587 	switch (target_proto) {
588 	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
589 		tech = NFC_DIGITAL_RF_TECH_106A;
590 		break;
591 	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
592 		tech = NFC_DIGITAL_RF_TECH_106B;
593 		break;
594 	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
595 		tech = NFC_DIGITAL_RF_TECH_212F;
596 		break;
597 	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
598 		tech = NFC_DIGITAL_RF_TECH_424F;
599 		break;
600 	default:
601 		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
602 				__func__, target_proto);
603 		return -EIO;
604 	}
605 
606 	*rf_tech = tech;
607 
608 	return ret;
609 }
610 
611 static void trf7970a_send_upstream(struct trf7970a *trf)
612 {
613 	dev_kfree_skb_any(trf->tx_skb);
614 	trf->tx_skb = NULL;
615 
616 	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
617 		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
618 				16, 1, trf->rx_skb->data, trf->rx_skb->len,
619 				false);
620 
621 	trf->state = TRF7970A_ST_IDLE;
622 
623 	if (trf->aborting) {
624 		dev_dbg(trf->dev, "Abort process complete\n");
625 
626 		if (!IS_ERR(trf->rx_skb)) {
627 			kfree_skb(trf->rx_skb);
628 			trf->rx_skb = ERR_PTR(-ECANCELED);
629 		}
630 
631 		trf->aborting = false;
632 	}
633 
634 	if (trf->adjust_resp_len) {
635 		if (trf->rx_skb)
636 			skb_trim(trf->rx_skb, trf->rx_skb->len - 1);
637 
638 		trf->adjust_resp_len = false;
639 	}
640 
641 	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
642 
643 	trf->rx_skb = NULL;
644 }
645 
646 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
647 {
648 	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
649 
650 	cancel_delayed_work(&trf->timeout_work);
651 
652 	kfree_skb(trf->rx_skb);
653 	trf->rx_skb = ERR_PTR(errno);
654 
655 	trf7970a_send_upstream(trf);
656 }
657 
658 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
659 		unsigned int len, u8 *prefix, unsigned int prefix_len)
660 {
661 	struct spi_transfer t[2];
662 	struct spi_message m;
663 	unsigned int timeout;
664 	int ret;
665 
666 	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
667 			16, 1, skb->data, len, false);
668 
669 	spi_message_init(&m);
670 
671 	memset(&t, 0, sizeof(t));
672 
673 	t[0].tx_buf = prefix;
674 	t[0].len = prefix_len;
675 	spi_message_add_tail(&t[0], &m);
676 
677 	t[1].tx_buf = skb->data;
678 	t[1].len = len;
679 	spi_message_add_tail(&t[1], &m);
680 
681 	ret = spi_sync(trf->spi, &m);
682 	if (ret) {
683 		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
684 				ret);
685 		return ret;
686 	}
687 
688 	skb_pull(skb, len);
689 
690 	if (skb->len > 0) {
691 		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
692 		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
693 	} else {
694 		if (trf->issue_eof) {
695 			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
696 			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
697 		} else {
698 			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
699 
700 			if (!trf->timeout)
701 				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
702 			else
703 				timeout = trf->timeout;
704 		}
705 	}
706 
707 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
708 			trf->state);
709 
710 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
711 
712 	return 0;
713 }
714 
715 static void trf7970a_fill_fifo(struct trf7970a *trf)
716 {
717 	struct sk_buff *skb = trf->tx_skb;
718 	unsigned int len;
719 	int ret;
720 	u8 fifo_bytes;
721 	u8 prefix;
722 
723 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
724 	if (ret) {
725 		trf7970a_send_err_upstream(trf, ret);
726 		return;
727 	}
728 
729 	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
730 
731 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
732 
733 	/* Calculate how much more data can be written to the fifo */
734 	len = TRF7970A_FIFO_SIZE - fifo_bytes;
735 	if (!len) {
736 		schedule_delayed_work(&trf->timeout_work,
737 			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
738 		return;
739 	}
740 
741 	len = min(skb->len, len);
742 
743 	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
744 
745 	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
746 	if (ret)
747 		trf7970a_send_err_upstream(trf, ret);
748 }
749 
750 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
751 {
752 	struct sk_buff *skb = trf->rx_skb;
753 	int ret;
754 	u8 fifo_bytes;
755 
756 	if (status & TRF7970A_IRQ_STATUS_ERROR) {
757 		trf7970a_send_err_upstream(trf, -EIO);
758 		return;
759 	}
760 
761 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
762 	if (ret) {
763 		trf7970a_send_err_upstream(trf, ret);
764 		return;
765 	}
766 
767 	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
768 
769 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
770 
771 	if (!fifo_bytes)
772 		goto no_rx_data;
773 
774 	if (fifo_bytes > skb_tailroom(skb)) {
775 		skb = skb_copy_expand(skb, skb_headroom(skb),
776 				max_t(int, fifo_bytes,
777 					TRF7970A_RX_SKB_ALLOC_SIZE),
778 				GFP_KERNEL);
779 		if (!skb) {
780 			trf7970a_send_err_upstream(trf, -ENOMEM);
781 			return;
782 		}
783 
784 		kfree_skb(trf->rx_skb);
785 		trf->rx_skb = skb;
786 	}
787 
788 	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
789 			skb_put(skb, fifo_bytes), fifo_bytes);
790 	if (ret) {
791 		trf7970a_send_err_upstream(trf, ret);
792 		return;
793 	}
794 
795 	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
796 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
797 			(trf->special_fcn_reg1 ==
798 				 TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
799 		skb->data[0] >>= 4;
800 		status = TRF7970A_IRQ_STATUS_SRX;
801 	} else {
802 		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
803 
804 		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
805 		if (ret) {
806 			trf7970a_send_err_upstream(trf, ret);
807 			return;
808 		}
809 
810 		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
811 
812 		/* If there are bytes in the FIFO, set status to '0' so
813 		 * the if stmt below doesn't fire and the driver will wait
814 		 * for the trf7970a to generate another RX interrupt.
815 		 */
816 		if (fifo_bytes)
817 			status = 0;
818 	}
819 
820 no_rx_data:
821 	if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
822 		trf7970a_send_upstream(trf);
823 		return;
824 	}
825 
826 	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
827 			TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
828 
829 	schedule_delayed_work(&trf->timeout_work,
830 			msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
831 }
832 
833 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
834 {
835 	struct trf7970a *trf = dev_id;
836 	int ret;
837 	u8 status, fifo_bytes, iso_ctrl;
838 
839 	mutex_lock(&trf->lock);
840 
841 	if (trf->state == TRF7970A_ST_RF_OFF) {
842 		mutex_unlock(&trf->lock);
843 		return IRQ_NONE;
844 	}
845 
846 	ret = trf7970a_read_irqstatus(trf, &status);
847 	if (ret) {
848 		mutex_unlock(&trf->lock);
849 		return IRQ_NONE;
850 	}
851 
852 	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
853 			status);
854 
855 	if (!status) {
856 		mutex_unlock(&trf->lock);
857 		return IRQ_NONE;
858 	}
859 
860 	switch (trf->state) {
861 	case TRF7970A_ST_IDLE:
862 	case TRF7970A_ST_IDLE_RX_BLOCKED:
863 		/* If initiator and getting interrupts caused by RF noise,
864 		 * turn off the receiver to avoid unnecessary interrupts.
865 		 * It will be turned back on in trf7970a_send_cmd() when
866 		 * the next command is issued.
867 		 */
868 		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
869 			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
870 			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
871 		}
872 
873 		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
874 		break;
875 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
876 		if (status & TRF7970A_IRQ_STATUS_TX) {
877 			trf->ignore_timeout =
878 				!cancel_delayed_work(&trf->timeout_work);
879 			trf7970a_fill_fifo(trf);
880 		} else {
881 			trf7970a_send_err_upstream(trf, -EIO);
882 		}
883 		break;
884 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
885 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
886 		if (status & TRF7970A_IRQ_STATUS_SRX) {
887 			trf->ignore_timeout =
888 				!cancel_delayed_work(&trf->timeout_work);
889 			trf7970a_drain_fifo(trf, status);
890 		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
891 			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
892 					&fifo_bytes);
893 
894 			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
895 
896 			if (ret)
897 				trf7970a_send_err_upstream(trf, ret);
898 			else if (!fifo_bytes)
899 				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
900 		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
901 				(!trf->is_initiator &&
902 				 (status == (TRF7970A_IRQ_STATUS_TX |
903 					     TRF7970A_IRQ_STATUS_NFC_RF)))) {
904 			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
905 
906 			if (!trf->timeout) {
907 				trf->ignore_timeout = !cancel_delayed_work(
908 						&trf->timeout_work);
909 				trf->rx_skb = ERR_PTR(0);
910 				trf7970a_send_upstream(trf);
911 				break;
912 			}
913 
914 			if (trf->is_initiator)
915 				break;
916 
917 			iso_ctrl = trf->iso_ctrl;
918 
919 			switch (trf->framing) {
920 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
921 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
922 				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
923 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
924 				break;
925 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
926 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
927 				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
928 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
929 				break;
930 			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
931 				ret = trf7970a_write(trf,
932 					TRF7970A_SPECIAL_FCN_REG1,
933 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
934 				if (ret)
935 					goto err_unlock_exit;
936 
937 				trf->special_fcn_reg1 =
938 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
939 				break;
940 			default:
941 				break;
942 			}
943 
944 			if (iso_ctrl != trf->iso_ctrl) {
945 				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
946 						iso_ctrl);
947 				if (ret)
948 					goto err_unlock_exit;
949 
950 				trf->iso_ctrl = iso_ctrl;
951 			}
952 		} else {
953 			trf7970a_send_err_upstream(trf, -EIO);
954 		}
955 		break;
956 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
957 		if (status != TRF7970A_IRQ_STATUS_TX)
958 			trf7970a_send_err_upstream(trf, -EIO);
959 		break;
960 	case TRF7970A_ST_LISTENING:
961 		if (status & TRF7970A_IRQ_STATUS_SRX) {
962 			trf->ignore_timeout =
963 				!cancel_delayed_work(&trf->timeout_work);
964 			trf7970a_drain_fifo(trf, status);
965 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
966 			trf7970a_send_err_upstream(trf, -EIO);
967 		}
968 		break;
969 	case TRF7970A_ST_LISTENING_MD:
970 		if (status & TRF7970A_IRQ_STATUS_SRX) {
971 			trf->ignore_timeout =
972 				!cancel_delayed_work(&trf->timeout_work);
973 
974 			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
975 			if (ret) {
976 				trf7970a_send_err_upstream(trf, ret);
977 			} else {
978 				trf->state = TRF7970A_ST_LISTENING;
979 				trf7970a_drain_fifo(trf, status);
980 			}
981 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
982 			trf7970a_send_err_upstream(trf, -EIO);
983 		}
984 		break;
985 	default:
986 		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
987 				__func__, trf->state);
988 	}
989 
990 err_unlock_exit:
991 	mutex_unlock(&trf->lock);
992 	return IRQ_HANDLED;
993 }
994 
995 static void trf7970a_issue_eof(struct trf7970a *trf)
996 {
997 	int ret;
998 
999 	dev_dbg(trf->dev, "Issuing EOF\n");
1000 
1001 	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
1002 	if (ret)
1003 		trf7970a_send_err_upstream(trf, ret);
1004 
1005 	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1006 	if (ret)
1007 		trf7970a_send_err_upstream(trf, ret);
1008 
1009 	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1010 
1011 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1012 			trf->timeout, trf->state);
1013 
1014 	schedule_delayed_work(&trf->timeout_work,
1015 			msecs_to_jiffies(trf->timeout));
1016 }
1017 
1018 static void trf7970a_timeout_work_handler(struct work_struct *work)
1019 {
1020 	struct trf7970a *trf = container_of(work, struct trf7970a,
1021 			timeout_work.work);
1022 
1023 	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1024 			trf->state, trf->ignore_timeout);
1025 
1026 	mutex_lock(&trf->lock);
1027 
1028 	if (trf->ignore_timeout)
1029 		trf->ignore_timeout = false;
1030 	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1031 		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1032 	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1033 		trf7970a_issue_eof(trf);
1034 	else
1035 		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1036 
1037 	mutex_unlock(&trf->lock);
1038 }
1039 
1040 static int trf7970a_init(struct trf7970a *trf)
1041 {
1042 	int ret;
1043 
1044 	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1045 
1046 	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1047 	if (ret)
1048 		goto err_out;
1049 
1050 	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1051 	if (ret)
1052 		goto err_out;
1053 
1054 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1055 			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1056 	if (ret)
1057 		goto err_out;
1058 
1059 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1060 	if (ret)
1061 		goto err_out;
1062 
1063 	usleep_range(1000, 2000);
1064 
1065 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1066 
1067 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1068 			trf->modulator_sys_clk_ctrl);
1069 	if (ret)
1070 		goto err_out;
1071 
1072 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1073 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1074 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1075 	if (ret)
1076 		goto err_out;
1077 
1078 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1079 	if (ret)
1080 		goto err_out;
1081 
1082 	trf->special_fcn_reg1 = 0;
1083 
1084 	trf->iso_ctrl = 0xff;
1085 	return 0;
1086 
1087 err_out:
1088 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1089 	return ret;
1090 }
1091 
1092 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1093 {
1094 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1095 			(trf->state == TRF7970A_ST_RF_OFF))
1096 		return;
1097 
1098 	dev_dbg(trf->dev, "Switching rf off\n");
1099 
1100 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1101 
1102 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1103 
1104 	trf->aborting = false;
1105 	trf->state = TRF7970A_ST_RF_OFF;
1106 
1107 	pm_runtime_mark_last_busy(trf->dev);
1108 	pm_runtime_put_autosuspend(trf->dev);
1109 }
1110 
1111 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1112 {
1113 	int ret;
1114 
1115 	dev_dbg(trf->dev, "Switching rf on\n");
1116 
1117 	pm_runtime_get_sync(trf->dev);
1118 
1119 	if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1120 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1121 				trf->state);
1122 		return -EINVAL;
1123 	}
1124 
1125 	ret = trf7970a_init(trf);
1126 	if (ret) {
1127 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1128 		return ret;
1129 	}
1130 
1131 	trf->state = TRF7970A_ST_IDLE;
1132 
1133 	return 0;
1134 }
1135 
1136 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1137 {
1138 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1139 	int ret = 0;
1140 
1141 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1142 
1143 	mutex_lock(&trf->lock);
1144 
1145 	if (on) {
1146 		switch (trf->state) {
1147 		case TRF7970A_ST_PWR_OFF:
1148 		case TRF7970A_ST_RF_OFF:
1149 			ret = trf7970a_switch_rf_on(trf);
1150 			break;
1151 		case TRF7970A_ST_IDLE:
1152 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1153 			break;
1154 		default:
1155 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1156 					__func__, trf->state, on);
1157 			trf7970a_switch_rf_off(trf);
1158 			ret = -EINVAL;
1159 		}
1160 	} else {
1161 		switch (trf->state) {
1162 		case TRF7970A_ST_PWR_OFF:
1163 		case TRF7970A_ST_RF_OFF:
1164 			break;
1165 		default:
1166 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1167 					__func__, trf->state, on);
1168 			ret = -EINVAL;
1169 			/* FALLTHROUGH */
1170 		case TRF7970A_ST_IDLE:
1171 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1172 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1173 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1174 			trf7970a_switch_rf_off(trf);
1175 		}
1176 	}
1177 
1178 	mutex_unlock(&trf->lock);
1179 	return ret;
1180 }
1181 
1182 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1183 {
1184 	int ret = 0;
1185 
1186 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1187 
1188 	switch (tech) {
1189 	case NFC_DIGITAL_RF_TECH_106A:
1190 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1191 		trf->modulator_sys_clk_ctrl =
1192 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1193 			TRF7970A_MODULATOR_DEPTH_OOK;
1194 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1195 		break;
1196 	case NFC_DIGITAL_RF_TECH_106B:
1197 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1198 		trf->modulator_sys_clk_ctrl =
1199 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1200 			TRF7970A_MODULATOR_DEPTH_ASK10;
1201 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1202 		break;
1203 	case NFC_DIGITAL_RF_TECH_212F:
1204 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1205 		trf->modulator_sys_clk_ctrl =
1206 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1207 			TRF7970A_MODULATOR_DEPTH_ASK10;
1208 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1209 		break;
1210 	case NFC_DIGITAL_RF_TECH_424F:
1211 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1212 		trf->modulator_sys_clk_ctrl =
1213 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1214 			TRF7970A_MODULATOR_DEPTH_ASK10;
1215 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1216 		break;
1217 	case NFC_DIGITAL_RF_TECH_ISO15693:
1218 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1219 		trf->modulator_sys_clk_ctrl =
1220 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1221 			TRF7970A_MODULATOR_DEPTH_OOK;
1222 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1223 		break;
1224 	default:
1225 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1226 		return -EINVAL;
1227 	}
1228 
1229 	trf->technology = tech;
1230 
1231 	/* If in initiator mode and not changing the RF tech due to a
1232 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1233 	 * trf7970a_init()), clear the NFC Target Detection Level register
1234 	 * due to erratum.
1235 	 */
1236 	if (trf->iso_ctrl == 0xff)
1237 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1238 
1239 	return ret;
1240 }
1241 
1242 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1243 {
1244 	int ret;
1245 	u8 rssi;
1246 
1247 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1248 			trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
1249 	if (ret)
1250 		return ret;
1251 
1252 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1253 	if (ret)
1254 		return ret;
1255 
1256 	usleep_range(50, 60);
1257 
1258 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1259 	if (ret)
1260 		return ret;
1261 
1262 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1263 			trf->chip_status_ctrl);
1264 	if (ret)
1265 		return ret;
1266 
1267 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1268 		*is_rf_field = true;
1269 	else
1270 		*is_rf_field = false;
1271 
1272 	return 0;
1273 }
1274 
1275 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1276 {
1277 	u8 iso_ctrl = trf->iso_ctrl_tech;
1278 	bool is_rf_field = false;
1279 	int ret;
1280 
1281 	dev_dbg(trf->dev, "framing: %d\n", framing);
1282 
1283 	switch (framing) {
1284 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1285 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1286 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1287 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1288 		break;
1289 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1290 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1291 	case NFC_DIGITAL_FRAMING_NFCB:
1292 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1293 	case NFC_DIGITAL_FRAMING_NFCF:
1294 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1295 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1296 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1297 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1298 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1299 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1300 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1301 		break;
1302 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1303 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1304 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1305 		break;
1306 	default:
1307 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1308 		return -EINVAL;
1309 	}
1310 
1311 	trf->framing = framing;
1312 
1313 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1314 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1315 		if (ret)
1316 			return ret;
1317 
1318 		if (is_rf_field)
1319 			return -EBUSY;
1320 	}
1321 
1322 	if (iso_ctrl != trf->iso_ctrl) {
1323 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1324 		if (ret)
1325 			return ret;
1326 
1327 		trf->iso_ctrl = iso_ctrl;
1328 
1329 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1330 				trf->modulator_sys_clk_ctrl);
1331 		if (ret)
1332 			return ret;
1333 	}
1334 
1335 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1336 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1337 				trf->chip_status_ctrl |
1338 					TRF7970A_CHIP_STATUS_RF_ON);
1339 		if (ret)
1340 			return ret;
1341 
1342 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1343 
1344 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1345 	}
1346 
1347 	return 0;
1348 }
1349 
1350 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1351 		int param)
1352 {
1353 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1354 	int ret;
1355 
1356 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1357 
1358 	mutex_lock(&trf->lock);
1359 
1360 	trf->is_initiator = true;
1361 
1362 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1363 			(trf->state == TRF7970A_ST_RF_OFF)) {
1364 		ret = trf7970a_switch_rf_on(trf);
1365 		if (ret)
1366 			goto err_unlock;
1367 	}
1368 
1369 	switch (type) {
1370 	case NFC_DIGITAL_CONFIG_RF_TECH:
1371 		ret = trf7970a_in_config_rf_tech(trf, param);
1372 		break;
1373 	case NFC_DIGITAL_CONFIG_FRAMING:
1374 		ret = trf7970a_in_config_framing(trf, param);
1375 		break;
1376 	default:
1377 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1378 		ret = -EINVAL;
1379 	}
1380 
1381 err_unlock:
1382 	mutex_unlock(&trf->lock);
1383 	return ret;
1384 }
1385 
1386 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1387 {
1388 	switch (cmd) {
1389 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1390 	case ISO15693_CMD_LOCK_BLOCK:
1391 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1392 	case ISO15693_CMD_WRITE_AFI:
1393 	case ISO15693_CMD_LOCK_AFI:
1394 	case ISO15693_CMD_WRITE_DSFID:
1395 	case ISO15693_CMD_LOCK_DSFID:
1396 		return 1;
1397 		break;
1398 	default:
1399 		return 0;
1400 	}
1401 }
1402 
1403 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1404 {
1405 	u8 *req = skb->data;
1406 	u8 special_fcn_reg1, iso_ctrl;
1407 	int ret;
1408 
1409 	trf->issue_eof = false;
1410 
1411 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1412 	 * special functions register 1 is cleared; otherwise, its a write or
1413 	 * sector select command and '4_bit_RX' must be set.
1414 	 *
1415 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1416 	 * what speed to use.  Also, remember if the OPTION flag is set on
1417 	 * a Type 5 write or lock command so the driver will know that it
1418 	 * has to send an EOF in order to get a response.
1419 	 */
1420 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1421 			(trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1422 		if (req[0] == NFC_T2T_CMD_READ)
1423 			special_fcn_reg1 = 0;
1424 		else
1425 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1426 
1427 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1428 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1429 					special_fcn_reg1);
1430 			if (ret)
1431 				return ret;
1432 
1433 			trf->special_fcn_reg1 = special_fcn_reg1;
1434 		}
1435 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1436 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1437 
1438 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1439 		case 0x00:
1440 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1441 			break;
1442 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1443 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1444 			break;
1445 		case ISO15693_REQ_FLAG_DATA_RATE:
1446 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1447 			break;
1448 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1449 				ISO15693_REQ_FLAG_DATA_RATE):
1450 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1451 			break;
1452 		}
1453 
1454 		if (iso_ctrl != trf->iso_ctrl) {
1455 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1456 			if (ret)
1457 				return ret;
1458 
1459 			trf->iso_ctrl = iso_ctrl;
1460 		}
1461 
1462 		if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
1463 			if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
1464 					(req[0] & ISO15693_REQ_FLAG_OPTION))
1465 				trf->issue_eof = true;
1466 			else if ((trf->quirks &
1467 					TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
1468 				 (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
1469 				trf->adjust_resp_len = true;
1470 		}
1471 	}
1472 
1473 	return 0;
1474 }
1475 
1476 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1477 		struct sk_buff *skb, u16 timeout,
1478 		nfc_digital_cmd_complete_t cb, void *arg)
1479 {
1480 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1481 	u8 prefix[5];
1482 	unsigned int len;
1483 	int ret;
1484 	u8 status;
1485 
1486 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1487 			trf->state, timeout, skb->len);
1488 
1489 	if (skb->len > TRF7970A_TX_MAX)
1490 		return -EINVAL;
1491 
1492 	mutex_lock(&trf->lock);
1493 
1494 	if ((trf->state != TRF7970A_ST_IDLE) &&
1495 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1496 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1497 				trf->state);
1498 		ret = -EIO;
1499 		goto out_err;
1500 	}
1501 
1502 	if (trf->aborting) {
1503 		dev_dbg(trf->dev, "Abort process complete\n");
1504 		trf->aborting = false;
1505 		ret = -ECANCELED;
1506 		goto out_err;
1507 	}
1508 
1509 	if (timeout) {
1510 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1511 				GFP_KERNEL);
1512 		if (!trf->rx_skb) {
1513 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1514 			ret = -ENOMEM;
1515 			goto out_err;
1516 		}
1517 	}
1518 
1519 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1520 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1521 		if (ret)
1522 			goto out_err;
1523 
1524 		trf->state = TRF7970A_ST_IDLE;
1525 	}
1526 
1527 	if (trf->is_initiator) {
1528 		ret = trf7970a_per_cmd_config(trf, skb);
1529 		if (ret)
1530 			goto out_err;
1531 	}
1532 
1533 	trf->ddev = ddev;
1534 	trf->tx_skb = skb;
1535 	trf->cb = cb;
1536 	trf->cb_arg = arg;
1537 	trf->timeout = timeout;
1538 	trf->ignore_timeout = false;
1539 
1540 	len = skb->len;
1541 
1542 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1543 	 * on what the current framing is, the address of the TX length byte 1
1544 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1545 	 * That totals 5 bytes.
1546 	 */
1547 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1548 			TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1549 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1550 			TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1551 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1552 
1553 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1554 		prefix[3] = 0x00;
1555 		prefix[4] = 0x0f; /* 7 bits */
1556 	} else {
1557 		prefix[3] = (len & 0xf00) >> 4;
1558 		prefix[3] |= ((len & 0xf0) >> 4);
1559 		prefix[4] = ((len & 0x0f) << 4);
1560 	}
1561 
1562 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1563 
1564 	/* Clear possible spurious interrupt */
1565 	ret = trf7970a_read_irqstatus(trf, &status);
1566 	if (ret)
1567 		goto out_err;
1568 
1569 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1570 	if (ret) {
1571 		kfree_skb(trf->rx_skb);
1572 		trf->rx_skb = NULL;
1573 	}
1574 
1575 out_err:
1576 	mutex_unlock(&trf->lock);
1577 	return ret;
1578 }
1579 
1580 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1581 {
1582 	int ret = 0;
1583 
1584 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1585 
1586 	switch (tech) {
1587 	case NFC_DIGITAL_RF_TECH_106A:
1588 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1589 			TRF7970A_ISO_CTRL_NFC_CE |
1590 			TRF7970A_ISO_CTRL_NFC_CE_14443A;
1591 		trf->modulator_sys_clk_ctrl =
1592 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1593 			TRF7970A_MODULATOR_DEPTH_OOK;
1594 		break;
1595 	case NFC_DIGITAL_RF_TECH_212F:
1596 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1597 			TRF7970A_ISO_CTRL_NFC_NFCF_212;
1598 		trf->modulator_sys_clk_ctrl =
1599 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1600 			TRF7970A_MODULATOR_DEPTH_ASK10;
1601 		break;
1602 	case NFC_DIGITAL_RF_TECH_424F:
1603 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1604 			TRF7970A_ISO_CTRL_NFC_NFCF_424;
1605 		trf->modulator_sys_clk_ctrl =
1606 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1607 			TRF7970A_MODULATOR_DEPTH_ASK10;
1608 		break;
1609 	default:
1610 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1611 		return -EINVAL;
1612 	}
1613 
1614 	trf->technology = tech;
1615 
1616 	/* Normally we write the ISO_CTRL register in
1617 	 * trf7970a_tg_config_framing() because the framing can change
1618 	 * the value written.  However, when sending a PSL RES,
1619 	 * digital_tg_send_psl_res_complete() doesn't call
1620 	 * trf7970a_tg_config_framing() so we must write the register
1621 	 * here.
1622 	 */
1623 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1624 			(trf->iso_ctrl_tech != trf->iso_ctrl)) {
1625 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1626 				trf->iso_ctrl_tech);
1627 
1628 		trf->iso_ctrl = trf->iso_ctrl_tech;
1629 	}
1630 
1631 	return ret;
1632 }
1633 
1634 /* Since this is a target routine, several of the framing calls are
1635  * made between receiving the request and sending the response so they
1636  * should take effect until after the response is sent.  This is accomplished
1637  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1638  * handler.
1639  */
1640 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1641 {
1642 	u8 iso_ctrl = trf->iso_ctrl_tech;
1643 	int ret;
1644 
1645 	dev_dbg(trf->dev, "framing: %d\n", framing);
1646 
1647 	switch (framing) {
1648 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1649 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1650 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1651 		break;
1652 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1653 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1654 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1655 		/* These ones are applied in the interrupt handler */
1656 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1657 		break;
1658 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1659 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1660 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1661 		break;
1662 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1663 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1664 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1665 		break;
1666 	default:
1667 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1668 		return -EINVAL;
1669 	}
1670 
1671 	trf->framing = framing;
1672 
1673 	if (iso_ctrl != trf->iso_ctrl) {
1674 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1675 		if (ret)
1676 			return ret;
1677 
1678 		trf->iso_ctrl = iso_ctrl;
1679 
1680 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1681 				trf->modulator_sys_clk_ctrl);
1682 		if (ret)
1683 			return ret;
1684 	}
1685 
1686 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1687 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1688 				trf->chip_status_ctrl |
1689 					TRF7970A_CHIP_STATUS_RF_ON);
1690 		if (ret)
1691 			return ret;
1692 
1693 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1694 	}
1695 
1696 	return 0;
1697 }
1698 
1699 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1700 		int param)
1701 {
1702 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1703 	int ret;
1704 
1705 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1706 
1707 	mutex_lock(&trf->lock);
1708 
1709 	trf->is_initiator = false;
1710 
1711 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1712 			(trf->state == TRF7970A_ST_RF_OFF)) {
1713 		ret = trf7970a_switch_rf_on(trf);
1714 		if (ret)
1715 			goto err_unlock;
1716 	}
1717 
1718 	switch (type) {
1719 	case NFC_DIGITAL_CONFIG_RF_TECH:
1720 		ret = trf7970a_tg_config_rf_tech(trf, param);
1721 		break;
1722 	case NFC_DIGITAL_CONFIG_FRAMING:
1723 		ret = trf7970a_tg_config_framing(trf, param);
1724 		break;
1725 	default:
1726 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1727 		ret = -EINVAL;
1728 	}
1729 
1730 err_unlock:
1731 	mutex_unlock(&trf->lock);
1732 	return ret;
1733 }
1734 
1735 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1736 		nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
1737 {
1738 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1739 	int ret;
1740 
1741 	mutex_lock(&trf->lock);
1742 
1743 	if ((trf->state != TRF7970A_ST_IDLE) &&
1744 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1745 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1746 				trf->state);
1747 		ret = -EIO;
1748 		goto out_err;
1749 	}
1750 
1751 	if (trf->aborting) {
1752 		dev_dbg(trf->dev, "Abort process complete\n");
1753 		trf->aborting = false;
1754 		ret = -ECANCELED;
1755 		goto out_err;
1756 	}
1757 
1758 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1759 			GFP_KERNEL);
1760 	if (!trf->rx_skb) {
1761 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1762 		ret = -ENOMEM;
1763 		goto out_err;
1764 	}
1765 
1766 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1767 			TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1768 			TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1769 			TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1770 			TRF7970A_RX_SPECIAL_SETTINGS_C212);
1771 	if (ret)
1772 		goto out_err;
1773 
1774 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1775 			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1776 	if (ret)
1777 		goto out_err;
1778 
1779 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1780 			TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1781 	if (ret)
1782 		goto out_err;
1783 
1784 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1785 			TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1786 	if (ret)
1787 		goto out_err;
1788 
1789 	trf->ddev = ddev;
1790 	trf->cb = cb;
1791 	trf->cb_arg = arg;
1792 	trf->timeout = timeout;
1793 	trf->ignore_timeout = false;
1794 
1795 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1796 	if (ret)
1797 		goto out_err;
1798 
1799 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1800 				   TRF7970A_ST_LISTENING;
1801 
1802 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1803 
1804 out_err:
1805 	mutex_unlock(&trf->lock);
1806 	return ret;
1807 }
1808 
1809 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1810 		nfc_digital_cmd_complete_t cb, void *arg)
1811 {
1812 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1813 
1814 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1815 			trf->state, timeout);
1816 
1817 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1818 }
1819 
1820 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1821 		u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1822 {
1823 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1824 	int ret;
1825 
1826 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1827 			trf->state, timeout);
1828 
1829 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1830 			NFC_DIGITAL_RF_TECH_106A);
1831 	if (ret)
1832 		return ret;
1833 
1834 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1835 			NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1836 	if (ret)
1837 		return ret;
1838 
1839 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1840 }
1841 
1842 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1843 {
1844 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1845 
1846 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1847 			trf->state, trf->md_rf_tech);
1848 
1849 	*rf_tech = trf->md_rf_tech;
1850 
1851 	return 0;
1852 }
1853 
1854 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1855 {
1856 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1857 
1858 	dev_dbg(trf->dev, "Abort process initiated\n");
1859 
1860 	mutex_lock(&trf->lock);
1861 
1862 	switch (trf->state) {
1863 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1864 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1865 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1866 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1867 		trf->aborting = true;
1868 		break;
1869 	case TRF7970A_ST_LISTENING:
1870 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1871 		trf7970a_send_err_upstream(trf, -ECANCELED);
1872 		dev_dbg(trf->dev, "Abort process complete\n");
1873 		break;
1874 	default:
1875 		break;
1876 	}
1877 
1878 	mutex_unlock(&trf->lock);
1879 }
1880 
1881 static struct nfc_digital_ops trf7970a_nfc_ops = {
1882 	.in_configure_hw	= trf7970a_in_configure_hw,
1883 	.in_send_cmd		= trf7970a_send_cmd,
1884 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1885 	.tg_send_cmd		= trf7970a_send_cmd,
1886 	.tg_listen		= trf7970a_tg_listen,
1887 	.tg_listen_md		= trf7970a_tg_listen_md,
1888 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1889 	.switch_rf		= trf7970a_switch_rf,
1890 	.abort_cmd		= trf7970a_abort_cmd,
1891 };
1892 
1893 static int trf7970a_power_up(struct trf7970a *trf)
1894 {
1895 	int ret;
1896 
1897 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1898 
1899 	if (trf->state != TRF7970A_ST_PWR_OFF)
1900 		return 0;
1901 
1902 	ret = regulator_enable(trf->regulator);
1903 	if (ret) {
1904 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1905 		return ret;
1906 	}
1907 
1908 	usleep_range(5000, 6000);
1909 
1910 	if (trf->en2_gpiod &&
1911 	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1912 		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1913 		usleep_range(1000, 2000);
1914 	}
1915 
1916 	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1917 
1918 	usleep_range(20000, 21000);
1919 
1920 	trf->state = TRF7970A_ST_RF_OFF;
1921 
1922 	return 0;
1923 }
1924 
1925 static int trf7970a_power_down(struct trf7970a *trf)
1926 {
1927 	int ret;
1928 
1929 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1930 
1931 	if (trf->state == TRF7970A_ST_PWR_OFF)
1932 		return 0;
1933 
1934 	if (trf->state != TRF7970A_ST_RF_OFF) {
1935 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1936 				trf->state);
1937 		return -EBUSY;
1938 	}
1939 
1940 	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1941 
1942 	if (trf->en2_gpiod &&
1943 	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1944 		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1945 
1946 	ret = regulator_disable(trf->regulator);
1947 	if (ret)
1948 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1949 				ret);
1950 
1951 	trf->state = TRF7970A_ST_PWR_OFF;
1952 
1953 	return ret;
1954 }
1955 
1956 static int trf7970a_startup(struct trf7970a *trf)
1957 {
1958 	int ret;
1959 
1960 	ret = trf7970a_power_up(trf);
1961 	if (ret)
1962 		return ret;
1963 
1964 	pm_runtime_set_active(trf->dev);
1965 	pm_runtime_enable(trf->dev);
1966 	pm_runtime_mark_last_busy(trf->dev);
1967 
1968 	return 0;
1969 }
1970 
1971 static void trf7970a_shutdown(struct trf7970a *trf)
1972 {
1973 	switch (trf->state) {
1974 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1975 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1976 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1977 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1978 	case TRF7970A_ST_LISTENING:
1979 		trf7970a_send_err_upstream(trf, -ECANCELED);
1980 		/* FALLTHROUGH */
1981 	case TRF7970A_ST_IDLE:
1982 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1983 		trf7970a_switch_rf_off(trf);
1984 		break;
1985 	default:
1986 		break;
1987 	}
1988 
1989 	pm_runtime_disable(trf->dev);
1990 	pm_runtime_set_suspended(trf->dev);
1991 
1992 	trf7970a_power_down(trf);
1993 }
1994 
1995 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1996 {
1997 	int autosuspend_delay, ret;
1998 
1999 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
2000 	if (ret)
2001 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
2002 
2003 	return autosuspend_delay;
2004 }
2005 
2006 static int trf7970a_probe(struct spi_device *spi)
2007 {
2008 	struct device_node *np = spi->dev.of_node;
2009 	struct trf7970a *trf;
2010 	int uvolts, autosuspend_delay, ret;
2011 	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
2012 
2013 	if (!np) {
2014 		dev_err(&spi->dev, "No Device Tree entry\n");
2015 		return -EINVAL;
2016 	}
2017 
2018 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2019 	if (!trf)
2020 		return -ENOMEM;
2021 
2022 	trf->state = TRF7970A_ST_PWR_OFF;
2023 	trf->dev = &spi->dev;
2024 	trf->spi = spi;
2025 
2026 	spi->mode = SPI_MODE_1;
2027 	spi->bits_per_word = 8;
2028 
2029 	ret = spi_setup(spi);
2030 	if (ret < 0) {
2031 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2032 		return ret;
2033 	}
2034 
2035 	if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
2036 		trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
2037 
2038 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2039 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2040 
2041 	/* There are two enable pins - only EN must be present in the DT */
2042 	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2043 					     GPIOD_OUT_LOW);
2044 	if (IS_ERR(trf->en_gpiod)) {
2045 		dev_err(trf->dev, "No EN GPIO property\n");
2046 		return PTR_ERR(trf->en_gpiod);
2047 	}
2048 
2049 	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2050 						       GPIOD_OUT_LOW);
2051 	if (!trf->en2_gpiod) {
2052 		dev_info(trf->dev, "No EN2 GPIO property\n");
2053 	} else if (IS_ERR(trf->en2_gpiod)) {
2054 		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2055 			PTR_ERR(trf->en2_gpiod));
2056 		return PTR_ERR(trf->en2_gpiod);
2057 	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2058 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2059 	}
2060 
2061 	of_property_read_u32(np, "clock-frequency", &clk_freq);
2062 	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
2063 		(clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2064 		dev_err(trf->dev,
2065 			"clock-frequency (%u Hz) unsupported\n",
2066 			clk_freq);
2067 		return -EINVAL;
2068 	}
2069 
2070 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2071 			trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2072 			"trf7970a", trf);
2073 	if (ret) {
2074 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2075 		return ret;
2076 	}
2077 
2078 	mutex_init(&trf->lock);
2079 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2080 
2081 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2082 	if (IS_ERR(trf->regulator)) {
2083 		ret = PTR_ERR(trf->regulator);
2084 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2085 		goto err_destroy_lock;
2086 	}
2087 
2088 	ret = regulator_enable(trf->regulator);
2089 	if (ret) {
2090 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2091 		goto err_destroy_lock;
2092 	}
2093 
2094 	uvolts = regulator_get_voltage(trf->regulator);
2095 	if (uvolts > 4000000)
2096 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2097 
2098 	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2099 	if (IS_ERR(trf->regulator)) {
2100 		ret = PTR_ERR(trf->regulator);
2101 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2102 		goto err_destroy_lock;
2103 	}
2104 
2105 	ret = regulator_enable(trf->regulator);
2106 	if (ret) {
2107 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2108 		goto err_destroy_lock;
2109 	}
2110 
2111 	if (regulator_get_voltage(trf->regulator) == 1800000) {
2112 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2113 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2114 	}
2115 
2116 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2117 			TRF7970A_SUPPORTED_PROTOCOLS,
2118 			NFC_DIGITAL_DRV_CAPS_IN_CRC |
2119 				NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
2120 	if (!trf->ddev) {
2121 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2122 		ret = -ENOMEM;
2123 		goto err_disable_regulator;
2124 	}
2125 
2126 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2127 	nfc_digital_set_drvdata(trf->ddev, trf);
2128 	spi_set_drvdata(spi, trf);
2129 
2130 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2131 
2132 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2133 	pm_runtime_use_autosuspend(trf->dev);
2134 
2135 	ret = trf7970a_startup(trf);
2136 	if (ret)
2137 		goto err_free_ddev;
2138 
2139 	ret = nfc_digital_register_device(trf->ddev);
2140 	if (ret) {
2141 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2142 				ret);
2143 		goto err_shutdown;
2144 	}
2145 
2146 	return 0;
2147 
2148 err_shutdown:
2149 	trf7970a_shutdown(trf);
2150 err_free_ddev:
2151 	nfc_digital_free_device(trf->ddev);
2152 err_disable_regulator:
2153 	regulator_disable(trf->regulator);
2154 err_destroy_lock:
2155 	mutex_destroy(&trf->lock);
2156 	return ret;
2157 }
2158 
2159 static int trf7970a_remove(struct spi_device *spi)
2160 {
2161 	struct trf7970a *trf = spi_get_drvdata(spi);
2162 
2163 	mutex_lock(&trf->lock);
2164 
2165 	trf7970a_shutdown(trf);
2166 
2167 	mutex_unlock(&trf->lock);
2168 
2169 	nfc_digital_unregister_device(trf->ddev);
2170 	nfc_digital_free_device(trf->ddev);
2171 
2172 	regulator_disable(trf->regulator);
2173 
2174 	mutex_destroy(&trf->lock);
2175 
2176 	return 0;
2177 }
2178 
2179 #ifdef CONFIG_PM_SLEEP
2180 static int trf7970a_suspend(struct device *dev)
2181 {
2182 	struct spi_device *spi = to_spi_device(dev);
2183 	struct trf7970a *trf = spi_get_drvdata(spi);
2184 
2185 	dev_dbg(dev, "Suspend\n");
2186 
2187 	mutex_lock(&trf->lock);
2188 
2189 	trf7970a_shutdown(trf);
2190 
2191 	mutex_unlock(&trf->lock);
2192 
2193 	return 0;
2194 }
2195 
2196 static int trf7970a_resume(struct device *dev)
2197 {
2198 	struct spi_device *spi = to_spi_device(dev);
2199 	struct trf7970a *trf = spi_get_drvdata(spi);
2200 	int ret;
2201 
2202 	dev_dbg(dev, "Resume\n");
2203 
2204 	mutex_lock(&trf->lock);
2205 
2206 	ret = trf7970a_startup(trf);
2207 
2208 	mutex_unlock(&trf->lock);
2209 
2210 	return ret;
2211 }
2212 #endif
2213 
2214 #ifdef CONFIG_PM
2215 static int trf7970a_pm_runtime_suspend(struct device *dev)
2216 {
2217 	struct spi_device *spi = to_spi_device(dev);
2218 	struct trf7970a *trf = spi_get_drvdata(spi);
2219 	int ret;
2220 
2221 	dev_dbg(dev, "Runtime suspend\n");
2222 
2223 	mutex_lock(&trf->lock);
2224 
2225 	ret = trf7970a_power_down(trf);
2226 
2227 	mutex_unlock(&trf->lock);
2228 
2229 	return ret;
2230 }
2231 
2232 static int trf7970a_pm_runtime_resume(struct device *dev)
2233 {
2234 	struct spi_device *spi = to_spi_device(dev);
2235 	struct trf7970a *trf = spi_get_drvdata(spi);
2236 	int ret;
2237 
2238 	dev_dbg(dev, "Runtime resume\n");
2239 
2240 	ret = trf7970a_power_up(trf);
2241 	if (!ret)
2242 		pm_runtime_mark_last_busy(dev);
2243 
2244 	return ret;
2245 }
2246 #endif
2247 
2248 static const struct dev_pm_ops trf7970a_pm_ops = {
2249 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2250 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2251 			trf7970a_pm_runtime_resume, NULL)
2252 };
2253 
2254 static const struct of_device_id trf7970a_of_match[] = {
2255 	{ .compatible = "ti,trf7970a", },
2256 	{},
2257 };
2258 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2259 
2260 static const struct spi_device_id trf7970a_id_table[] = {
2261 	{ "trf7970a", 0 },
2262 	{ }
2263 };
2264 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2265 
2266 static struct spi_driver trf7970a_spi_driver = {
2267 	.probe		= trf7970a_probe,
2268 	.remove		= trf7970a_remove,
2269 	.id_table	= trf7970a_id_table,
2270 	.driver		= {
2271 		.name	= "trf7970a",
2272 		.of_match_table = of_match_ptr(trf7970a_of_match),
2273 		.pm	= &trf7970a_pm_ops,
2274 	},
2275 };
2276 
2277 module_spi_driver(trf7970a_spi_driver);
2278 
2279 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2280 MODULE_LICENSE("GPL v2");
2281 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2282