xref: /linux/drivers/nfc/trf7970a.c (revision a34631c2723797dd31e6f83538899eeb4c03b753)
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.h>
24 #include <linux/of.h>
25 #include <linux/of_gpio.h>
26 #include <linux/spi/spi.h>
27 #include <linux/regulator/consumer.h>
28 
29 #include <net/nfc/nfc.h>
30 #include <net/nfc/digital.h>
31 
32 /* There are 3 ways the host can communicate with the trf7970a:
33  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
34  * SS mode.  The driver only supports the two SPI modes.
35  *
36  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
37  * pins must asserted in that order and with specific delays in between.
38  * The delays used in the driver were provided by TI and have been
39  * confirmed to work with this driver.  There is a bug with the current
40  * version of the trf7970a that requires that EN2 remain low no matter
41  * what.  If it goes high, it will generate an RF field even when in
42  * passive target mode.  TI has indicated that the chip will work okay
43  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
44  * indicates that trf7970a currently being used has the erratum and
45  * that EN2 must be kept low.
46  *
47  * Timeouts are implemented using the delayed workqueue kernel facility.
48  * Timeouts are required so things don't hang when there is no response
49  * from the trf7970a (or tag).  Using this mechanism creates a race with
50  * interrupts, however.  That is, an interrupt and a timeout could occur
51  * closely enough together that one is blocked by the mutex while the other
52  * executes.  When the timeout handler executes first and blocks the
53  * interrupt handler, it will eventually set the state to IDLE so the
54  * interrupt handler will check the state and exit with no harm done.
55  * When the interrupt handler executes first and blocks the timeout handler,
56  * the cancel_delayed_work() call will know that it didn't cancel the
57  * work item (i.e., timeout) and will return zero.  That return code is
58  * used by the timer handler to indicate that it should ignore the timeout
59  * once its unblocked.
60  *
61  * Aborting an active command isn't as simple as it seems because the only
62  * way to abort a command that's already been sent to the tag is so turn
63  * off power to the tag.  If we do that, though, we'd have to go through
64  * the entire anticollision procedure again but the digital layer doesn't
65  * support that.  So, if an abort is received before trf7970a_send_cmd()
66  * has sent the command to the tag, it simply returns -ECANCELED.  If the
67  * command has already been sent to the tag, then the driver continues
68  * normally and recieves the response data (or error) but just before
69  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
70  * upstream instead.  If the command failed, that error will be sent
71  * upstream.
72  *
73  * When recieving data from a tag and the interrupt status register has
74  * only the SRX bit set, it means that all of the data has been received
75  * (once what's in the fifo has been read).  However, depending on timing
76  * an interrupt status with only the SRX bit set may not be recived.  In
77  * those cases, the timeout mechanism is used to wait 20 ms in case more
78  * data arrives.  After 20 ms, it is assumed that all of the data has been
79  * received and the accumulated rx data is sent upstream.  The
80  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
81  * (i.e., it indicates that some data has been received but we're not sure
82  * if there is more coming so a timeout in this state means all data has
83  * been received and there isn't an error).  The delay is 20 ms since delays
84  * of ~16 ms have been observed during testing.
85  *
86  * When transmitting a frame larger than the FIFO size (127 bytes), the
87  * driver will wait 20 ms for the FIFO to drain past the low-watermark
88  * and generate an interrupt.  The low-watermark set to 32 bytes so the
89  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
90  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
91  * to ~14.35 ms so 20 ms is used for the timeout.
92  *
93  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
94  * Having only 4 bits in the FIFO won't normally generate an interrupt so
95  * driver enables the '4_bit_RX' bit of the Special Functions register 1
96  * to cause an interrupt in that case.  Leaving that bit for a read command
97  * messes up the data returned so it is only enabled when the framing is
98  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
99  * Unfortunately, that means that the driver has to peek into tx frames
100  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
101  * the trf7970a_per_cmd_config() routine.
102  *
103  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
104  * frequencies and whether to use low or high data rates in the flags byte
105  * of the frame.  This means that the driver has to peek at all 15693 frames
106  * to determine what speed to set the communication to.  In addition, write
107  * and lock commands use the OPTION flag to indicate that an EOF must be
108  * sent to the tag before it will send its response.  So the driver has to
109  * examine all frames for that reason too.
110  *
111  * It is unclear how long to wait before sending the EOF.  According to the
112  * Note under Table 1-1 in section 1.6 of
113  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
114  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
115  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
116  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
117  * ensure the wait is long enough before sending the EOF.  This seems to work
118  * reliably.
119  */
120 
121 #define TRF7970A_SUPPORTED_PROTOCOLS \
122 		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\
123 		 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
124 		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
125 
126 #define TRF7970A_AUTOSUSPEND_DELAY		30000 /* 30 seconds */
127 #define TRF7970A_13MHZ_CLOCK_FREQUENCY		13560000
128 #define TRF7970A_27MHZ_CLOCK_FREQUENCY		27120000
129 
130 
131 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
132 
133 #define TRF7970A_FIFO_SIZE			127
134 
135 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
136 #define TRF7970A_TX_MAX				(4096 - 1)
137 
138 #define TRF7970A_WAIT_FOR_TX_IRQ		20
139 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
140 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
141 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
142 
143 /* Guard times for various RF technologies (in us) */
144 #define TRF7970A_GUARD_TIME_NFCA		5000
145 #define TRF7970A_GUARD_TIME_NFCB		5000
146 #define TRF7970A_GUARD_TIME_NFCF		20000
147 #define TRF7970A_GUARD_TIME_15693		1000
148 
149 /* Quirks */
150 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
151  * read continuous command for IRQ Status and Collision Position registers.
152  */
153 #define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
154 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
155 #define TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE	BIT(2)
156 
157 /* Direct commands */
158 #define TRF7970A_CMD_IDLE			0x00
159 #define TRF7970A_CMD_SOFT_INIT			0x03
160 #define TRF7970A_CMD_RF_COLLISION		0x04
161 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
162 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
163 #define TRF7970A_CMD_FIFO_RESET			0x0f
164 #define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
165 #define TRF7970A_CMD_TRANSMIT			0x11
166 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
167 #define TRF7970A_CMD_DELAY_TRANSMIT		0x13
168 #define TRF7970A_CMD_EOF			0x14
169 #define TRF7970A_CMD_CLOSE_SLOT			0x15
170 #define TRF7970A_CMD_BLOCK_RX			0x16
171 #define TRF7970A_CMD_ENABLE_RX			0x17
172 #define TRF7970A_CMD_TEST_INT_RF		0x18
173 #define TRF7970A_CMD_TEST_EXT_RF		0x19
174 #define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
175 
176 /* Bits determining whether its a direct command or register R/W,
177  * whether to use a continuous SPI transaction or not, and the actual
178  * direct cmd opcode or regster address.
179  */
180 #define TRF7970A_CMD_BIT_CTRL			BIT(7)
181 #define TRF7970A_CMD_BIT_RW			BIT(6)
182 #define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
183 #define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
184 
185 /* Registers addresses */
186 #define TRF7970A_CHIP_STATUS_CTRL		0x00
187 #define TRF7970A_ISO_CTRL			0x01
188 #define TRF7970A_ISO14443B_TX_OPTIONS		0x02
189 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
190 #define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
191 #define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
192 #define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
193 #define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
194 #define TRF7970A_RX_WAIT_TIME			0x08
195 #define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
196 #define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
197 #define TRF7970A_REG_IO_CTRL			0x0b
198 #define TRF7970A_IRQ_STATUS			0x0c
199 #define TRF7970A_COLLISION_IRQ_MASK		0x0d
200 #define TRF7970A_COLLISION_POSITION		0x0e
201 #define TRF7970A_RSSI_OSC_STATUS		0x0f
202 #define TRF7970A_SPECIAL_FCN_REG1		0x10
203 #define TRF7970A_SPECIAL_FCN_REG2		0x11
204 #define TRF7970A_RAM1				0x12
205 #define TRF7970A_RAM2				0x13
206 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
207 #define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
208 #define TRF7970A_NFCID1				0x17
209 #define TRF7970A_NFC_TARGET_LEVEL		0x18
210 #define TRF79070A_NFC_TARGET_PROTOCOL		0x19
211 #define TRF7970A_TEST_REGISTER1			0x1a
212 #define TRF7970A_TEST_REGISTER2			0x1b
213 #define TRF7970A_FIFO_STATUS			0x1c
214 #define TRF7970A_TX_LENGTH_BYTE1		0x1d
215 #define TRF7970A_TX_LENGTH_BYTE2		0x1e
216 #define TRF7970A_FIFO_IO_REGISTER		0x1f
217 
218 /* Chip Status Control Register Bits */
219 #define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
220 #define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
221 #define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
222 #define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
223 #define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
224 #define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
225 #define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
226 #define TRF7970A_CHIP_STATUS_STBY		BIT(7)
227 
228 /* ISO Control Register Bits */
229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
230 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
231 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
232 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
234 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
235 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
236 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
237 #define TRF7970A_ISO_CTRL_14443A_106		0x08
238 #define TRF7970A_ISO_CTRL_14443A_212		0x09
239 #define TRF7970A_ISO_CTRL_14443A_424		0x0a
240 #define TRF7970A_ISO_CTRL_14443A_848		0x0b
241 #define TRF7970A_ISO_CTRL_14443B_106		0x0c
242 #define TRF7970A_ISO_CTRL_14443B_212		0x0d
243 #define TRF7970A_ISO_CTRL_14443B_424		0x0e
244 #define TRF7970A_ISO_CTRL_14443B_848		0x0f
245 #define TRF7970A_ISO_CTRL_FELICA_212		0x1a
246 #define TRF7970A_ISO_CTRL_FELICA_424		0x1b
247 #define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
248 #define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
249 #define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
250 #define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
251 #define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
252 #define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
253 #define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
254 #define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
255 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
256 #define TRF7970A_ISO_CTRL_RFID			BIT(5)
257 #define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
258 #define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
259 
260 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
261 
262 /* Modulator and SYS_CLK Control Register Bits */
263 #define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
264 #define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
265 #define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
266 #define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
267 #define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
268 #define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
269 #define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
270 #define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
271 #define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
272 #define TRF7970A_MODULATOR_EN_ANA		BIT(3)
273 #define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
274 #define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
275 #define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
276 #define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
277 #define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
278 #define TRF7970A_MODULATOR_EN_OOK		BIT(6)
279 #define TRF7970A_MODULATOR_27MHZ		BIT(7)
280 
281 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
282 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
285 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
286 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
287 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
288 #define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
289 #define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
290 #define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
291 
292 #define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
293 #define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
294 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
295 #define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
296 
297 /* IRQ Status Register Bits */
298 #define TRF7970A_IRQ_STATUS_NORESP		BIT(0) /* ISO15693 only */
299 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
300 #define TRF7970A_IRQ_STATUS_COL			BIT(1)
301 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
302 #define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
303 #define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
304 #define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
305 #define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
306 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
307 #define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
308 #define TRF7970A_IRQ_STATUS_SRX			BIT(6)
309 #define TRF7970A_IRQ_STATUS_TX			BIT(7)
310 
311 #define TRF7970A_IRQ_STATUS_ERROR				\
312 		(TRF7970A_IRQ_STATUS_COL |			\
313 		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
314 		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
315 		 TRF7970A_IRQ_STATUS_CRC_ERROR)
316 
317 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
318 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
319 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
320 
321 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
322 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
323 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
324 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
325 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
326 #define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
327 
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
333 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
334 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
335 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
336 
337 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
338 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
339 
340 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
341 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
342 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
343 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
344 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
345 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
346 
347 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
349 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
350 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
351 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
352 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
353 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
354 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
355 
356 #define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
357 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
358 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
359 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
360 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
361 
362 #define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
363 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
364 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
365 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
366 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
367 
368 #define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
369 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
370 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
371 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
372 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
373 
374 #define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
375 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
376 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
377 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
378 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
379 
380 #define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
381 
382 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
383 #define NFC_T2T_CMD_READ			0x30
384 
385 /* ISO 15693 commands codes */
386 #define ISO15693_CMD_INVENTORY			0x01
387 #define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
388 #define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
389 #define ISO15693_CMD_LOCK_BLOCK			0x22
390 #define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
391 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
392 #define ISO15693_CMD_SELECT			0x25
393 #define ISO15693_CMD_RESET_TO_READY		0x26
394 #define ISO15693_CMD_WRITE_AFI			0x27
395 #define ISO15693_CMD_LOCK_AFI			0x28
396 #define ISO15693_CMD_WRITE_DSFID		0x29
397 #define ISO15693_CMD_LOCK_DSFID			0x2a
398 #define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
399 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
400 
401 /* ISO 15693 request and response flags */
402 #define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
403 #define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
404 #define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
405 #define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
406 #define ISO15693_REQ_FLAG_SELECT		BIT(4)
407 #define ISO15693_REQ_FLAG_AFI			BIT(4)
408 #define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
409 #define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
410 #define ISO15693_REQ_FLAG_OPTION		BIT(6)
411 
412 #define ISO15693_REQ_FLAG_SPEED_MASK \
413 		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
414 
415 enum trf7970a_state {
416 	TRF7970A_ST_PWR_OFF,
417 	TRF7970A_ST_RF_OFF,
418 	TRF7970A_ST_IDLE,
419 	TRF7970A_ST_IDLE_RX_BLOCKED,
420 	TRF7970A_ST_WAIT_FOR_TX_FIFO,
421 	TRF7970A_ST_WAIT_FOR_RX_DATA,
422 	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
423 	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
424 	TRF7970A_ST_LISTENING,
425 	TRF7970A_ST_LISTENING_MD,
426 	TRF7970A_ST_MAX
427 };
428 
429 struct trf7970a {
430 	enum trf7970a_state		state;
431 	struct device			*dev;
432 	struct spi_device		*spi;
433 	struct regulator		*regulator;
434 	struct nfc_digital_dev		*ddev;
435 	u32				quirks;
436 	bool				is_initiator;
437 	bool				aborting;
438 	struct sk_buff			*tx_skb;
439 	struct sk_buff			*rx_skb;
440 	nfc_digital_cmd_complete_t	cb;
441 	void				*cb_arg;
442 	u8				chip_status_ctrl;
443 	u8				iso_ctrl;
444 	u8				iso_ctrl_tech;
445 	u8				modulator_sys_clk_ctrl;
446 	u8				special_fcn_reg1;
447 	u8				io_ctrl;
448 	unsigned int			guard_time;
449 	int				technology;
450 	int				framing;
451 	u8				md_rf_tech;
452 	u8				tx_cmd;
453 	bool				issue_eof;
454 	bool				adjust_resp_len;
455 	int				en2_gpio;
456 	int				en_gpio;
457 	struct mutex			lock;
458 	unsigned int			timeout;
459 	bool				ignore_timeout;
460 	struct delayed_work		timeout_work;
461 };
462 
463 
464 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
465 {
466 	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
467 	int ret;
468 
469 	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
470 
471 	ret = spi_write(trf->spi, &cmd, 1);
472 	if (ret)
473 		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
474 				ret);
475 	return ret;
476 }
477 
478 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
479 {
480 	u8 addr = TRF7970A_CMD_BIT_RW | reg;
481 	int ret;
482 
483 	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
484 	if (ret)
485 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
486 				ret);
487 
488 	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
489 
490 	return ret;
491 }
492 
493 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, size_t len)
494 {
495 	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
496 	struct spi_transfer t[2];
497 	struct spi_message m;
498 	int ret;
499 
500 	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
501 
502 	spi_message_init(&m);
503 
504 	memset(&t, 0, sizeof(t));
505 
506 	t[0].tx_buf = &addr;
507 	t[0].len = sizeof(addr);
508 	spi_message_add_tail(&t[0], &m);
509 
510 	t[1].rx_buf = buf;
511 	t[1].len = len;
512 	spi_message_add_tail(&t[1], &m);
513 
514 	ret = spi_sync(trf->spi, &m);
515 	if (ret)
516 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
517 				ret);
518 	return ret;
519 }
520 
521 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
522 {
523 	u8 buf[2] = { reg, val };
524 	int ret;
525 
526 	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
527 
528 	ret = spi_write(trf->spi, buf, 2);
529 	if (ret)
530 		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
531 				buf[0], buf[1], ret);
532 
533 	return ret;
534 }
535 
536 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
537 {
538 	int ret;
539 	u8 buf[2];
540 	u8 addr;
541 
542 	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
543 
544 	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
545 		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
546 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
547 	} else {
548 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
549 	}
550 
551 	if (ret)
552 		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
553 				__func__, ret);
554 	else
555 		*status = buf[0];
556 
557 	return ret;
558 }
559 
560 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
561 {
562 	int ret;
563 	u8 buf[2];
564 	u8 addr;
565 
566 	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
567 		TRF7970A_CMD_BIT_CONTINUOUS;
568 
569 	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
570 	if (ret)
571 		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
572 				__func__, ret);
573 	else
574 		*target_proto = buf[0];
575 
576 	return ret;
577 }
578 
579 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
580 {
581 	int ret;
582 	u8 target_proto, tech;
583 
584 	ret = trf7970a_read_target_proto(trf, &target_proto);
585 	if (ret)
586 		return ret;
587 
588 	switch (target_proto) {
589 	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
590 		tech = NFC_DIGITAL_RF_TECH_106A;
591 		break;
592 	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
593 		tech = NFC_DIGITAL_RF_TECH_106B;
594 		break;
595 	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
596 		tech = NFC_DIGITAL_RF_TECH_212F;
597 		break;
598 	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
599 		tech = NFC_DIGITAL_RF_TECH_424F;
600 		break;
601 	default:
602 		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
603 				__func__, target_proto);
604 		return -EIO;
605 	}
606 
607 	*rf_tech = tech;
608 
609 	return ret;
610 }
611 
612 static void trf7970a_send_upstream(struct trf7970a *trf)
613 {
614 	dev_kfree_skb_any(trf->tx_skb);
615 	trf->tx_skb = NULL;
616 
617 	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
618 		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
619 				16, 1, trf->rx_skb->data, trf->rx_skb->len,
620 				false);
621 
622 	trf->state = TRF7970A_ST_IDLE;
623 
624 	if (trf->aborting) {
625 		dev_dbg(trf->dev, "Abort process complete\n");
626 
627 		if (!IS_ERR(trf->rx_skb)) {
628 			kfree_skb(trf->rx_skb);
629 			trf->rx_skb = ERR_PTR(-ECANCELED);
630 		}
631 
632 		trf->aborting = false;
633 	}
634 
635 	if (trf->adjust_resp_len) {
636 		if (trf->rx_skb)
637 			skb_trim(trf->rx_skb, trf->rx_skb->len - 1);
638 
639 		trf->adjust_resp_len = false;
640 	}
641 
642 	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
643 
644 	trf->rx_skb = NULL;
645 }
646 
647 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
648 {
649 	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
650 
651 	cancel_delayed_work(&trf->timeout_work);
652 
653 	kfree_skb(trf->rx_skb);
654 	trf->rx_skb = ERR_PTR(errno);
655 
656 	trf7970a_send_upstream(trf);
657 }
658 
659 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
660 		unsigned int len, u8 *prefix, unsigned int prefix_len)
661 {
662 	struct spi_transfer t[2];
663 	struct spi_message m;
664 	unsigned int timeout;
665 	int ret;
666 
667 	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
668 			16, 1, skb->data, len, false);
669 
670 	spi_message_init(&m);
671 
672 	memset(&t, 0, sizeof(t));
673 
674 	t[0].tx_buf = prefix;
675 	t[0].len = prefix_len;
676 	spi_message_add_tail(&t[0], &m);
677 
678 	t[1].tx_buf = skb->data;
679 	t[1].len = len;
680 	spi_message_add_tail(&t[1], &m);
681 
682 	ret = spi_sync(trf->spi, &m);
683 	if (ret) {
684 		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
685 				ret);
686 		return ret;
687 	}
688 
689 	skb_pull(skb, len);
690 
691 	if (skb->len > 0) {
692 		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
693 		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
694 	} else {
695 		if (trf->issue_eof) {
696 			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
697 			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
698 		} else {
699 			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
700 
701 			if (!trf->timeout)
702 				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
703 			else
704 				timeout = trf->timeout;
705 		}
706 	}
707 
708 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
709 			trf->state);
710 
711 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
712 
713 	return 0;
714 }
715 
716 static void trf7970a_fill_fifo(struct trf7970a *trf)
717 {
718 	struct sk_buff *skb = trf->tx_skb;
719 	unsigned int len;
720 	int ret;
721 	u8 fifo_bytes;
722 	u8 prefix;
723 
724 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
725 	if (ret) {
726 		trf7970a_send_err_upstream(trf, ret);
727 		return;
728 	}
729 
730 	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
731 
732 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
733 
734 	/* Calculate how much more data can be written to the fifo */
735 	len = TRF7970A_FIFO_SIZE - fifo_bytes;
736 	if (!len) {
737 		schedule_delayed_work(&trf->timeout_work,
738 			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
739 		return;
740 	}
741 
742 	len = min(skb->len, len);
743 
744 	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
745 
746 	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
747 	if (ret)
748 		trf7970a_send_err_upstream(trf, ret);
749 }
750 
751 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
752 {
753 	struct sk_buff *skb = trf->rx_skb;
754 	int ret;
755 	u8 fifo_bytes;
756 
757 	if (status & TRF7970A_IRQ_STATUS_ERROR) {
758 		trf7970a_send_err_upstream(trf, -EIO);
759 		return;
760 	}
761 
762 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
763 	if (ret) {
764 		trf7970a_send_err_upstream(trf, ret);
765 		return;
766 	}
767 
768 	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
769 
770 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
771 
772 	if (!fifo_bytes)
773 		goto no_rx_data;
774 
775 	if (fifo_bytes > skb_tailroom(skb)) {
776 		skb = skb_copy_expand(skb, skb_headroom(skb),
777 				max_t(int, fifo_bytes,
778 					TRF7970A_RX_SKB_ALLOC_SIZE),
779 				GFP_KERNEL);
780 		if (!skb) {
781 			trf7970a_send_err_upstream(trf, -ENOMEM);
782 			return;
783 		}
784 
785 		kfree_skb(trf->rx_skb);
786 		trf->rx_skb = skb;
787 	}
788 
789 	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
790 			skb_put(skb, fifo_bytes), fifo_bytes);
791 	if (ret) {
792 		trf7970a_send_err_upstream(trf, ret);
793 		return;
794 	}
795 
796 	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
797 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
798 			(trf->special_fcn_reg1 ==
799 				 TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
800 		skb->data[0] >>= 4;
801 		status = TRF7970A_IRQ_STATUS_SRX;
802 	} else {
803 		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
804 
805 		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
806 		if (ret) {
807 			trf7970a_send_err_upstream(trf, ret);
808 			return;
809 		}
810 
811 		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
812 
813 		/* If there are bytes in the FIFO, set status to '0' so
814 		 * the if stmt below doesn't fire and the driver will wait
815 		 * for the trf7970a to generate another RX interrupt.
816 		 */
817 		if (fifo_bytes)
818 			status = 0;
819 	}
820 
821 no_rx_data:
822 	if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
823 		trf7970a_send_upstream(trf);
824 		return;
825 	}
826 
827 	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
828 			TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
829 
830 	schedule_delayed_work(&trf->timeout_work,
831 			msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
832 }
833 
834 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
835 {
836 	struct trf7970a *trf = dev_id;
837 	int ret;
838 	u8 status, fifo_bytes, iso_ctrl;
839 
840 	mutex_lock(&trf->lock);
841 
842 	if (trf->state == TRF7970A_ST_RF_OFF) {
843 		mutex_unlock(&trf->lock);
844 		return IRQ_NONE;
845 	}
846 
847 	ret = trf7970a_read_irqstatus(trf, &status);
848 	if (ret) {
849 		mutex_unlock(&trf->lock);
850 		return IRQ_NONE;
851 	}
852 
853 	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
854 			status);
855 
856 	if (!status) {
857 		mutex_unlock(&trf->lock);
858 		return IRQ_NONE;
859 	}
860 
861 	switch (trf->state) {
862 	case TRF7970A_ST_IDLE:
863 	case TRF7970A_ST_IDLE_RX_BLOCKED:
864 		/* If initiator and getting interrupts caused by RF noise,
865 		 * turn off the receiver to avoid unnecessary interrupts.
866 		 * It will be turned back on in trf7970a_send_cmd() when
867 		 * the next command is issued.
868 		 */
869 		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
870 			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
871 			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
872 		}
873 
874 		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
875 		break;
876 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
877 		if (status & TRF7970A_IRQ_STATUS_TX) {
878 			trf->ignore_timeout =
879 				!cancel_delayed_work(&trf->timeout_work);
880 			trf7970a_fill_fifo(trf);
881 		} else {
882 			trf7970a_send_err_upstream(trf, -EIO);
883 		}
884 		break;
885 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
886 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
887 		if (status & TRF7970A_IRQ_STATUS_SRX) {
888 			trf->ignore_timeout =
889 				!cancel_delayed_work(&trf->timeout_work);
890 			trf7970a_drain_fifo(trf, status);
891 		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
892 			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
893 					&fifo_bytes);
894 
895 			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
896 
897 			if (ret)
898 				trf7970a_send_err_upstream(trf, ret);
899 			else if (!fifo_bytes)
900 				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
901 		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
902 				(!trf->is_initiator &&
903 				 (status == (TRF7970A_IRQ_STATUS_TX |
904 					     TRF7970A_IRQ_STATUS_NFC_RF)))) {
905 			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
906 
907 			if (!trf->timeout) {
908 				trf->ignore_timeout = !cancel_delayed_work(
909 						&trf->timeout_work);
910 				trf->rx_skb = ERR_PTR(0);
911 				trf7970a_send_upstream(trf);
912 				break;
913 			}
914 
915 			if (trf->is_initiator)
916 				break;
917 
918 			iso_ctrl = trf->iso_ctrl;
919 
920 			switch (trf->framing) {
921 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
922 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
923 				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
924 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
925 				break;
926 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
927 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
928 				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
929 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
930 				break;
931 			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
932 				ret = trf7970a_write(trf,
933 					TRF7970A_SPECIAL_FCN_REG1,
934 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
935 				if (ret)
936 					goto err_unlock_exit;
937 
938 				trf->special_fcn_reg1 =
939 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
940 				break;
941 			default:
942 				break;
943 			}
944 
945 			if (iso_ctrl != trf->iso_ctrl) {
946 				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
947 						iso_ctrl);
948 				if (ret)
949 					goto err_unlock_exit;
950 
951 				trf->iso_ctrl = iso_ctrl;
952 			}
953 		} else {
954 			trf7970a_send_err_upstream(trf, -EIO);
955 		}
956 		break;
957 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
958 		if (status != TRF7970A_IRQ_STATUS_TX)
959 			trf7970a_send_err_upstream(trf, -EIO);
960 		break;
961 	case TRF7970A_ST_LISTENING:
962 		if (status & TRF7970A_IRQ_STATUS_SRX) {
963 			trf->ignore_timeout =
964 				!cancel_delayed_work(&trf->timeout_work);
965 			trf7970a_drain_fifo(trf, status);
966 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
967 			trf7970a_send_err_upstream(trf, -EIO);
968 		}
969 		break;
970 	case TRF7970A_ST_LISTENING_MD:
971 		if (status & TRF7970A_IRQ_STATUS_SRX) {
972 			trf->ignore_timeout =
973 				!cancel_delayed_work(&trf->timeout_work);
974 
975 			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
976 			if (ret) {
977 				trf7970a_send_err_upstream(trf, ret);
978 			} else {
979 				trf->state = TRF7970A_ST_LISTENING;
980 				trf7970a_drain_fifo(trf, status);
981 			}
982 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
983 			trf7970a_send_err_upstream(trf, -EIO);
984 		}
985 		break;
986 	default:
987 		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
988 				__func__, trf->state);
989 	}
990 
991 err_unlock_exit:
992 	mutex_unlock(&trf->lock);
993 	return IRQ_HANDLED;
994 }
995 
996 static void trf7970a_issue_eof(struct trf7970a *trf)
997 {
998 	int ret;
999 
1000 	dev_dbg(trf->dev, "Issuing EOF\n");
1001 
1002 	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
1003 	if (ret)
1004 		trf7970a_send_err_upstream(trf, ret);
1005 
1006 	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1007 	if (ret)
1008 		trf7970a_send_err_upstream(trf, ret);
1009 
1010 	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1011 
1012 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1013 			trf->timeout, trf->state);
1014 
1015 	schedule_delayed_work(&trf->timeout_work,
1016 			msecs_to_jiffies(trf->timeout));
1017 }
1018 
1019 static void trf7970a_timeout_work_handler(struct work_struct *work)
1020 {
1021 	struct trf7970a *trf = container_of(work, struct trf7970a,
1022 			timeout_work.work);
1023 
1024 	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1025 			trf->state, trf->ignore_timeout);
1026 
1027 	mutex_lock(&trf->lock);
1028 
1029 	if (trf->ignore_timeout)
1030 		trf->ignore_timeout = false;
1031 	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1032 		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1033 	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1034 		trf7970a_issue_eof(trf);
1035 	else
1036 		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1037 
1038 	mutex_unlock(&trf->lock);
1039 }
1040 
1041 static int trf7970a_init(struct trf7970a *trf)
1042 {
1043 	int ret;
1044 
1045 	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1046 
1047 	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1048 	if (ret)
1049 		goto err_out;
1050 
1051 	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1052 	if (ret)
1053 		goto err_out;
1054 
1055 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1056 			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1057 	if (ret)
1058 		goto err_out;
1059 
1060 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1061 	if (ret)
1062 		goto err_out;
1063 
1064 	usleep_range(1000, 2000);
1065 
1066 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1067 
1068 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1069 			trf->modulator_sys_clk_ctrl);
1070 	if (ret)
1071 		goto err_out;
1072 
1073 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1074 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1075 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1076 	if (ret)
1077 		goto err_out;
1078 
1079 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1080 	if (ret)
1081 		goto err_out;
1082 
1083 	trf->special_fcn_reg1 = 0;
1084 
1085 	trf->iso_ctrl = 0xff;
1086 	return 0;
1087 
1088 err_out:
1089 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1090 	return ret;
1091 }
1092 
1093 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1094 {
1095 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1096 			(trf->state == TRF7970A_ST_RF_OFF))
1097 		return;
1098 
1099 	dev_dbg(trf->dev, "Switching rf off\n");
1100 
1101 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1102 
1103 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1104 
1105 	trf->aborting = false;
1106 	trf->state = TRF7970A_ST_RF_OFF;
1107 
1108 	pm_runtime_mark_last_busy(trf->dev);
1109 	pm_runtime_put_autosuspend(trf->dev);
1110 }
1111 
1112 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1113 {
1114 	int ret;
1115 
1116 	dev_dbg(trf->dev, "Switching rf on\n");
1117 
1118 	pm_runtime_get_sync(trf->dev);
1119 
1120 	if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1121 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1122 				trf->state);
1123 		return -EINVAL;
1124 	}
1125 
1126 	ret = trf7970a_init(trf);
1127 	if (ret) {
1128 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1129 		return ret;
1130 	}
1131 
1132 	trf->state = TRF7970A_ST_IDLE;
1133 
1134 	return 0;
1135 }
1136 
1137 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1138 {
1139 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1140 	int ret = 0;
1141 
1142 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1143 
1144 	mutex_lock(&trf->lock);
1145 
1146 	if (on) {
1147 		switch (trf->state) {
1148 		case TRF7970A_ST_PWR_OFF:
1149 		case TRF7970A_ST_RF_OFF:
1150 			ret = trf7970a_switch_rf_on(trf);
1151 			break;
1152 		case TRF7970A_ST_IDLE:
1153 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1154 			break;
1155 		default:
1156 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1157 					__func__, trf->state, on);
1158 			trf7970a_switch_rf_off(trf);
1159 			ret = -EINVAL;
1160 		}
1161 	} else {
1162 		switch (trf->state) {
1163 		case TRF7970A_ST_PWR_OFF:
1164 		case TRF7970A_ST_RF_OFF:
1165 			break;
1166 		default:
1167 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1168 					__func__, trf->state, on);
1169 			ret = -EINVAL;
1170 			/* FALLTHROUGH */
1171 		case TRF7970A_ST_IDLE:
1172 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1173 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1174 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1175 			trf7970a_switch_rf_off(trf);
1176 		}
1177 	}
1178 
1179 	mutex_unlock(&trf->lock);
1180 	return ret;
1181 }
1182 
1183 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1184 {
1185 	int ret = 0;
1186 
1187 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1188 
1189 	switch (tech) {
1190 	case NFC_DIGITAL_RF_TECH_106A:
1191 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1192 		trf->modulator_sys_clk_ctrl =
1193 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1194 			TRF7970A_MODULATOR_DEPTH_OOK;
1195 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1196 		break;
1197 	case NFC_DIGITAL_RF_TECH_106B:
1198 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1199 		trf->modulator_sys_clk_ctrl =
1200 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1201 			TRF7970A_MODULATOR_DEPTH_ASK10;
1202 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1203 		break;
1204 	case NFC_DIGITAL_RF_TECH_212F:
1205 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1206 		trf->modulator_sys_clk_ctrl =
1207 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1208 			TRF7970A_MODULATOR_DEPTH_ASK10;
1209 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1210 		break;
1211 	case NFC_DIGITAL_RF_TECH_424F:
1212 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1213 		trf->modulator_sys_clk_ctrl =
1214 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1215 			TRF7970A_MODULATOR_DEPTH_ASK10;
1216 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1217 		break;
1218 	case NFC_DIGITAL_RF_TECH_ISO15693:
1219 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1220 		trf->modulator_sys_clk_ctrl =
1221 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1222 			TRF7970A_MODULATOR_DEPTH_OOK;
1223 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1224 		break;
1225 	default:
1226 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1227 		return -EINVAL;
1228 	}
1229 
1230 	trf->technology = tech;
1231 
1232 	/* If in initiator mode and not changing the RF tech due to a
1233 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1234 	 * trf7970a_init()), clear the NFC Target Detection Level register
1235 	 * due to erratum.
1236 	 */
1237 	if (trf->iso_ctrl == 0xff)
1238 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1239 
1240 	return ret;
1241 }
1242 
1243 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1244 {
1245 	int ret;
1246 	u8 rssi;
1247 
1248 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1249 			trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
1250 	if (ret)
1251 		return ret;
1252 
1253 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1254 	if (ret)
1255 		return ret;
1256 
1257 	usleep_range(50, 60);
1258 
1259 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1260 	if (ret)
1261 		return ret;
1262 
1263 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1264 			trf->chip_status_ctrl);
1265 	if (ret)
1266 		return ret;
1267 
1268 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1269 		*is_rf_field = true;
1270 	else
1271 		*is_rf_field = false;
1272 
1273 	return 0;
1274 }
1275 
1276 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1277 {
1278 	u8 iso_ctrl = trf->iso_ctrl_tech;
1279 	bool is_rf_field = false;
1280 	int ret;
1281 
1282 	dev_dbg(trf->dev, "framing: %d\n", framing);
1283 
1284 	switch (framing) {
1285 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1286 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1287 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1288 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1289 		break;
1290 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1291 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1292 	case NFC_DIGITAL_FRAMING_NFCB:
1293 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1294 	case NFC_DIGITAL_FRAMING_NFCF:
1295 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1296 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1297 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1298 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1299 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1300 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1301 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1302 		break;
1303 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1304 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1305 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1306 		break;
1307 	default:
1308 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1309 		return -EINVAL;
1310 	}
1311 
1312 	trf->framing = framing;
1313 
1314 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1315 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1316 		if (ret)
1317 			return ret;
1318 
1319 		if (is_rf_field)
1320 			return -EBUSY;
1321 	}
1322 
1323 	if (iso_ctrl != trf->iso_ctrl) {
1324 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1325 		if (ret)
1326 			return ret;
1327 
1328 		trf->iso_ctrl = iso_ctrl;
1329 
1330 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1331 				trf->modulator_sys_clk_ctrl);
1332 		if (ret)
1333 			return ret;
1334 	}
1335 
1336 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1337 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1338 				trf->chip_status_ctrl |
1339 					TRF7970A_CHIP_STATUS_RF_ON);
1340 		if (ret)
1341 			return ret;
1342 
1343 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1344 
1345 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1346 	}
1347 
1348 	return 0;
1349 }
1350 
1351 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1352 		int param)
1353 {
1354 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1355 	int ret;
1356 
1357 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1358 
1359 	mutex_lock(&trf->lock);
1360 
1361 	trf->is_initiator = true;
1362 
1363 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1364 			(trf->state == TRF7970A_ST_RF_OFF)) {
1365 		ret = trf7970a_switch_rf_on(trf);
1366 		if (ret)
1367 			goto err_unlock;
1368 	}
1369 
1370 	switch (type) {
1371 	case NFC_DIGITAL_CONFIG_RF_TECH:
1372 		ret = trf7970a_in_config_rf_tech(trf, param);
1373 		break;
1374 	case NFC_DIGITAL_CONFIG_FRAMING:
1375 		ret = trf7970a_in_config_framing(trf, param);
1376 		break;
1377 	default:
1378 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1379 		ret = -EINVAL;
1380 	}
1381 
1382 err_unlock:
1383 	mutex_unlock(&trf->lock);
1384 	return ret;
1385 }
1386 
1387 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1388 {
1389 	switch (cmd) {
1390 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1391 	case ISO15693_CMD_LOCK_BLOCK:
1392 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1393 	case ISO15693_CMD_WRITE_AFI:
1394 	case ISO15693_CMD_LOCK_AFI:
1395 	case ISO15693_CMD_WRITE_DSFID:
1396 	case ISO15693_CMD_LOCK_DSFID:
1397 		return 1;
1398 		break;
1399 	default:
1400 		return 0;
1401 	}
1402 }
1403 
1404 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1405 {
1406 	u8 *req = skb->data;
1407 	u8 special_fcn_reg1, iso_ctrl;
1408 	int ret;
1409 
1410 	trf->issue_eof = false;
1411 
1412 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1413 	 * special functions register 1 is cleared; otherwise, its a write or
1414 	 * sector select command and '4_bit_RX' must be set.
1415 	 *
1416 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1417 	 * what speed to use.  Also, remember if the OPTION flag is set on
1418 	 * a Type 5 write or lock command so the driver will know that it
1419 	 * has to send an EOF in order to get a response.
1420 	 */
1421 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1422 			(trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1423 		if (req[0] == NFC_T2T_CMD_READ)
1424 			special_fcn_reg1 = 0;
1425 		else
1426 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1427 
1428 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1429 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1430 					special_fcn_reg1);
1431 			if (ret)
1432 				return ret;
1433 
1434 			trf->special_fcn_reg1 = special_fcn_reg1;
1435 		}
1436 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1437 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1438 
1439 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1440 		case 0x00:
1441 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1442 			break;
1443 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1444 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1445 			break;
1446 		case ISO15693_REQ_FLAG_DATA_RATE:
1447 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1448 			break;
1449 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1450 				ISO15693_REQ_FLAG_DATA_RATE):
1451 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1452 			break;
1453 		}
1454 
1455 		if (iso_ctrl != trf->iso_ctrl) {
1456 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1457 			if (ret)
1458 				return ret;
1459 
1460 			trf->iso_ctrl = iso_ctrl;
1461 		}
1462 
1463 		if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
1464 			if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
1465 					(req[0] & ISO15693_REQ_FLAG_OPTION))
1466 				trf->issue_eof = true;
1467 			else if ((trf->quirks &
1468 					TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
1469 				 (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
1470 				trf->adjust_resp_len = true;
1471 		}
1472 	}
1473 
1474 	return 0;
1475 }
1476 
1477 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1478 		struct sk_buff *skb, u16 timeout,
1479 		nfc_digital_cmd_complete_t cb, void *arg)
1480 {
1481 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1482 	u8 prefix[5];
1483 	unsigned int len;
1484 	int ret;
1485 	u8 status;
1486 
1487 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1488 			trf->state, timeout, skb->len);
1489 
1490 	if (skb->len > TRF7970A_TX_MAX)
1491 		return -EINVAL;
1492 
1493 	mutex_lock(&trf->lock);
1494 
1495 	if ((trf->state != TRF7970A_ST_IDLE) &&
1496 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1497 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1498 				trf->state);
1499 		ret = -EIO;
1500 		goto out_err;
1501 	}
1502 
1503 	if (trf->aborting) {
1504 		dev_dbg(trf->dev, "Abort process complete\n");
1505 		trf->aborting = false;
1506 		ret = -ECANCELED;
1507 		goto out_err;
1508 	}
1509 
1510 	if (timeout) {
1511 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1512 				GFP_KERNEL);
1513 		if (!trf->rx_skb) {
1514 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1515 			ret = -ENOMEM;
1516 			goto out_err;
1517 		}
1518 	}
1519 
1520 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1521 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1522 		if (ret)
1523 			goto out_err;
1524 
1525 		trf->state = TRF7970A_ST_IDLE;
1526 	}
1527 
1528 	if (trf->is_initiator) {
1529 		ret = trf7970a_per_cmd_config(trf, skb);
1530 		if (ret)
1531 			goto out_err;
1532 	}
1533 
1534 	trf->ddev = ddev;
1535 	trf->tx_skb = skb;
1536 	trf->cb = cb;
1537 	trf->cb_arg = arg;
1538 	trf->timeout = timeout;
1539 	trf->ignore_timeout = false;
1540 
1541 	len = skb->len;
1542 
1543 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1544 	 * on what the current framing is, the address of the TX length byte 1
1545 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1546 	 * That totals 5 bytes.
1547 	 */
1548 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1549 			TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1550 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1551 			TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1552 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1553 
1554 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1555 		prefix[3] = 0x00;
1556 		prefix[4] = 0x0f; /* 7 bits */
1557 	} else {
1558 		prefix[3] = (len & 0xf00) >> 4;
1559 		prefix[3] |= ((len & 0xf0) >> 4);
1560 		prefix[4] = ((len & 0x0f) << 4);
1561 	}
1562 
1563 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1564 
1565 	/* Clear possible spurious interrupt */
1566 	ret = trf7970a_read_irqstatus(trf, &status);
1567 	if (ret)
1568 		goto out_err;
1569 
1570 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1571 	if (ret) {
1572 		kfree_skb(trf->rx_skb);
1573 		trf->rx_skb = NULL;
1574 	}
1575 
1576 out_err:
1577 	mutex_unlock(&trf->lock);
1578 	return ret;
1579 }
1580 
1581 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1582 {
1583 	int ret = 0;
1584 
1585 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1586 
1587 	switch (tech) {
1588 	case NFC_DIGITAL_RF_TECH_106A:
1589 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1590 			TRF7970A_ISO_CTRL_NFC_CE |
1591 			TRF7970A_ISO_CTRL_NFC_CE_14443A;
1592 		trf->modulator_sys_clk_ctrl =
1593 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1594 			TRF7970A_MODULATOR_DEPTH_OOK;
1595 		break;
1596 	case NFC_DIGITAL_RF_TECH_212F:
1597 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1598 			TRF7970A_ISO_CTRL_NFC_NFCF_212;
1599 		trf->modulator_sys_clk_ctrl =
1600 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1601 			TRF7970A_MODULATOR_DEPTH_ASK10;
1602 		break;
1603 	case NFC_DIGITAL_RF_TECH_424F:
1604 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1605 			TRF7970A_ISO_CTRL_NFC_NFCF_424;
1606 		trf->modulator_sys_clk_ctrl =
1607 			(trf->modulator_sys_clk_ctrl & 0xf8) |
1608 			TRF7970A_MODULATOR_DEPTH_ASK10;
1609 		break;
1610 	default:
1611 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1612 		return -EINVAL;
1613 	}
1614 
1615 	trf->technology = tech;
1616 
1617 	/* Normally we write the ISO_CTRL register in
1618 	 * trf7970a_tg_config_framing() because the framing can change
1619 	 * the value written.  However, when sending a PSL RES,
1620 	 * digital_tg_send_psl_res_complete() doesn't call
1621 	 * trf7970a_tg_config_framing() so we must write the register
1622 	 * here.
1623 	 */
1624 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1625 			(trf->iso_ctrl_tech != trf->iso_ctrl)) {
1626 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1627 				trf->iso_ctrl_tech);
1628 
1629 		trf->iso_ctrl = trf->iso_ctrl_tech;
1630 	}
1631 
1632 	return ret;
1633 }
1634 
1635 /* Since this is a target routine, several of the framing calls are
1636  * made between receiving the request and sending the response so they
1637  * should take effect until after the response is sent.  This is accomplished
1638  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1639  * handler.
1640  */
1641 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1642 {
1643 	u8 iso_ctrl = trf->iso_ctrl_tech;
1644 	int ret;
1645 
1646 	dev_dbg(trf->dev, "framing: %d\n", framing);
1647 
1648 	switch (framing) {
1649 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1650 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1651 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1652 		break;
1653 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1654 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1655 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1656 		/* These ones are applied in the interrupt handler */
1657 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1658 		break;
1659 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1660 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1661 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1662 		break;
1663 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1664 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1665 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1666 		break;
1667 	default:
1668 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1669 		return -EINVAL;
1670 	}
1671 
1672 	trf->framing = framing;
1673 
1674 	if (iso_ctrl != trf->iso_ctrl) {
1675 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1676 		if (ret)
1677 			return ret;
1678 
1679 		trf->iso_ctrl = iso_ctrl;
1680 
1681 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1682 				trf->modulator_sys_clk_ctrl);
1683 		if (ret)
1684 			return ret;
1685 	}
1686 
1687 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1688 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1689 				trf->chip_status_ctrl |
1690 					TRF7970A_CHIP_STATUS_RF_ON);
1691 		if (ret)
1692 			return ret;
1693 
1694 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1695 	}
1696 
1697 	return 0;
1698 }
1699 
1700 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1701 		int param)
1702 {
1703 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1704 	int ret;
1705 
1706 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1707 
1708 	mutex_lock(&trf->lock);
1709 
1710 	trf->is_initiator = false;
1711 
1712 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1713 			(trf->state == TRF7970A_ST_RF_OFF)) {
1714 		ret = trf7970a_switch_rf_on(trf);
1715 		if (ret)
1716 			goto err_unlock;
1717 	}
1718 
1719 	switch (type) {
1720 	case NFC_DIGITAL_CONFIG_RF_TECH:
1721 		ret = trf7970a_tg_config_rf_tech(trf, param);
1722 		break;
1723 	case NFC_DIGITAL_CONFIG_FRAMING:
1724 		ret = trf7970a_tg_config_framing(trf, param);
1725 		break;
1726 	default:
1727 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1728 		ret = -EINVAL;
1729 	}
1730 
1731 err_unlock:
1732 	mutex_unlock(&trf->lock);
1733 	return ret;
1734 }
1735 
1736 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1737 		nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
1738 {
1739 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1740 	int ret;
1741 
1742 	mutex_lock(&trf->lock);
1743 
1744 	if ((trf->state != TRF7970A_ST_IDLE) &&
1745 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1746 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1747 				trf->state);
1748 		ret = -EIO;
1749 		goto out_err;
1750 	}
1751 
1752 	if (trf->aborting) {
1753 		dev_dbg(trf->dev, "Abort process complete\n");
1754 		trf->aborting = false;
1755 		ret = -ECANCELED;
1756 		goto out_err;
1757 	}
1758 
1759 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1760 			GFP_KERNEL);
1761 	if (!trf->rx_skb) {
1762 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1763 		ret = -ENOMEM;
1764 		goto out_err;
1765 	}
1766 
1767 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1768 			TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1769 			TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1770 			TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1771 			TRF7970A_RX_SPECIAL_SETTINGS_C212);
1772 	if (ret)
1773 		goto out_err;
1774 
1775 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1776 			trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1777 	if (ret)
1778 		goto out_err;
1779 
1780 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1781 			TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1782 	if (ret)
1783 		goto out_err;
1784 
1785 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1786 			TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1787 	if (ret)
1788 		goto out_err;
1789 
1790 	trf->ddev = ddev;
1791 	trf->cb = cb;
1792 	trf->cb_arg = arg;
1793 	trf->timeout = timeout;
1794 	trf->ignore_timeout = false;
1795 
1796 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1797 	if (ret)
1798 		goto out_err;
1799 
1800 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1801 				   TRF7970A_ST_LISTENING;
1802 
1803 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1804 
1805 out_err:
1806 	mutex_unlock(&trf->lock);
1807 	return ret;
1808 }
1809 
1810 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1811 		nfc_digital_cmd_complete_t cb, void *arg)
1812 {
1813 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1814 
1815 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1816 			trf->state, timeout);
1817 
1818 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1819 }
1820 
1821 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1822 		u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1823 {
1824 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1825 	int ret;
1826 
1827 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1828 			trf->state, timeout);
1829 
1830 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1831 			NFC_DIGITAL_RF_TECH_106A);
1832 	if (ret)
1833 		return ret;
1834 
1835 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1836 			NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1837 	if (ret)
1838 		return ret;
1839 
1840 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1841 }
1842 
1843 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1844 {
1845 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1846 
1847 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1848 			trf->state, trf->md_rf_tech);
1849 
1850 	*rf_tech = trf->md_rf_tech;
1851 
1852 	return 0;
1853 }
1854 
1855 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1856 {
1857 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1858 
1859 	dev_dbg(trf->dev, "Abort process initiated\n");
1860 
1861 	mutex_lock(&trf->lock);
1862 
1863 	switch (trf->state) {
1864 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1865 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1866 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1867 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1868 		trf->aborting = true;
1869 		break;
1870 	case TRF7970A_ST_LISTENING:
1871 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1872 		trf7970a_send_err_upstream(trf, -ECANCELED);
1873 		dev_dbg(trf->dev, "Abort process complete\n");
1874 		break;
1875 	default:
1876 		break;
1877 	}
1878 
1879 	mutex_unlock(&trf->lock);
1880 }
1881 
1882 static struct nfc_digital_ops trf7970a_nfc_ops = {
1883 	.in_configure_hw	= trf7970a_in_configure_hw,
1884 	.in_send_cmd		= trf7970a_send_cmd,
1885 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1886 	.tg_send_cmd		= trf7970a_send_cmd,
1887 	.tg_listen		= trf7970a_tg_listen,
1888 	.tg_listen_md		= trf7970a_tg_listen_md,
1889 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1890 	.switch_rf		= trf7970a_switch_rf,
1891 	.abort_cmd		= trf7970a_abort_cmd,
1892 };
1893 
1894 static int trf7970a_power_up(struct trf7970a *trf)
1895 {
1896 	int ret;
1897 
1898 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1899 
1900 	if (trf->state != TRF7970A_ST_PWR_OFF)
1901 		return 0;
1902 
1903 	ret = regulator_enable(trf->regulator);
1904 	if (ret) {
1905 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1906 		return ret;
1907 	}
1908 
1909 	usleep_range(5000, 6000);
1910 
1911 	if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1912 		if (gpio_is_valid(trf->en2_gpio)) {
1913 			gpio_set_value(trf->en2_gpio, 1);
1914 			usleep_range(1000, 2000);
1915 		}
1916 	}
1917 
1918 	gpio_set_value(trf->en_gpio, 1);
1919 
1920 	usleep_range(20000, 21000);
1921 
1922 	trf->state = TRF7970A_ST_RF_OFF;
1923 
1924 	return 0;
1925 }
1926 
1927 static int trf7970a_power_down(struct trf7970a *trf)
1928 {
1929 	int ret;
1930 
1931 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1932 
1933 	if (trf->state == TRF7970A_ST_PWR_OFF)
1934 		return 0;
1935 
1936 	if (trf->state != TRF7970A_ST_RF_OFF) {
1937 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1938 				trf->state);
1939 		return -EBUSY;
1940 	}
1941 
1942 	gpio_set_value(trf->en_gpio, 0);
1943 
1944 	if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1945 		if (gpio_is_valid(trf->en2_gpio))
1946 			gpio_set_value(trf->en2_gpio, 0);
1947 
1948 	ret = regulator_disable(trf->regulator);
1949 	if (ret)
1950 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1951 				ret);
1952 
1953 	trf->state = TRF7970A_ST_PWR_OFF;
1954 
1955 	return ret;
1956 }
1957 
1958 static int trf7970a_startup(struct trf7970a *trf)
1959 {
1960 	int ret;
1961 
1962 	ret = trf7970a_power_up(trf);
1963 	if (ret)
1964 		return ret;
1965 
1966 	pm_runtime_set_active(trf->dev);
1967 	pm_runtime_enable(trf->dev);
1968 	pm_runtime_mark_last_busy(trf->dev);
1969 
1970 	return 0;
1971 }
1972 
1973 static void trf7970a_shutdown(struct trf7970a *trf)
1974 {
1975 	switch (trf->state) {
1976 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1977 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1978 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1979 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1980 	case TRF7970A_ST_LISTENING:
1981 		trf7970a_send_err_upstream(trf, -ECANCELED);
1982 		/* FALLTHROUGH */
1983 	case TRF7970A_ST_IDLE:
1984 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1985 		trf7970a_switch_rf_off(trf);
1986 		break;
1987 	default:
1988 		break;
1989 	}
1990 
1991 	pm_runtime_disable(trf->dev);
1992 	pm_runtime_set_suspended(trf->dev);
1993 
1994 	trf7970a_power_down(trf);
1995 }
1996 
1997 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1998 {
1999 	int autosuspend_delay, ret;
2000 
2001 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
2002 	if (ret)
2003 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
2004 
2005 	return autosuspend_delay;
2006 }
2007 
2008 static int trf7970a_probe(struct spi_device *spi)
2009 {
2010 	struct device_node *np = spi->dev.of_node;
2011 	struct trf7970a *trf;
2012 	int uvolts, autosuspend_delay, ret;
2013 	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
2014 
2015 	if (!np) {
2016 		dev_err(&spi->dev, "No Device Tree entry\n");
2017 		return -EINVAL;
2018 	}
2019 
2020 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2021 	if (!trf)
2022 		return -ENOMEM;
2023 
2024 	trf->state = TRF7970A_ST_PWR_OFF;
2025 	trf->dev = &spi->dev;
2026 	trf->spi = spi;
2027 
2028 	spi->mode = SPI_MODE_1;
2029 	spi->bits_per_word = 8;
2030 
2031 	ret = spi_setup(spi);
2032 	if (ret < 0) {
2033 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2034 		return ret;
2035 	}
2036 
2037 	if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
2038 		trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
2039 
2040 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2041 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2042 
2043 	/* There are two enable pins - only EN must be present in the DT */
2044 	trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
2045 	if (!gpio_is_valid(trf->en_gpio)) {
2046 		dev_err(trf->dev, "No EN GPIO property\n");
2047 		return trf->en_gpio;
2048 	}
2049 
2050 	ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
2051 			GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN");
2052 	if (ret) {
2053 		dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
2054 		return ret;
2055 	}
2056 
2057 	trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
2058 	if (!gpio_is_valid(trf->en2_gpio)) {
2059 		dev_info(trf->dev, "No EN2 GPIO property\n");
2060 	} else {
2061 		ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
2062 				GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
2063 		if (ret) {
2064 			dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
2065 			return ret;
2066 		}
2067 
2068 		if (of_property_read_bool(np, "en2-rf-quirk"))
2069 			trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2070 	}
2071 
2072 	of_property_read_u32(np, "clock-frequency", &clk_freq);
2073 	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
2074 		(clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2075 		dev_err(trf->dev,
2076 			"clock-frequency (%u Hz) unsupported\n",
2077 			clk_freq);
2078 		return -EINVAL;
2079 	}
2080 
2081 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2082 			trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2083 			"trf7970a", trf);
2084 	if (ret) {
2085 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2086 		return ret;
2087 	}
2088 
2089 	mutex_init(&trf->lock);
2090 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2091 
2092 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2093 	if (IS_ERR(trf->regulator)) {
2094 		ret = PTR_ERR(trf->regulator);
2095 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2096 		goto err_destroy_lock;
2097 	}
2098 
2099 	ret = regulator_enable(trf->regulator);
2100 	if (ret) {
2101 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2102 		goto err_destroy_lock;
2103 	}
2104 
2105 	uvolts = regulator_get_voltage(trf->regulator);
2106 	if (uvolts > 4000000)
2107 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2108 
2109 	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2110 	if (IS_ERR(trf->regulator)) {
2111 		ret = PTR_ERR(trf->regulator);
2112 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2113 		goto err_destroy_lock;
2114 	}
2115 
2116 	ret = regulator_enable(trf->regulator);
2117 	if (ret) {
2118 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2119 		goto err_destroy_lock;
2120 	}
2121 
2122 	if (regulator_get_voltage(trf->regulator) == 1800000) {
2123 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2124 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2125 	}
2126 
2127 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2128 			TRF7970A_SUPPORTED_PROTOCOLS,
2129 			NFC_DIGITAL_DRV_CAPS_IN_CRC |
2130 				NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
2131 	if (!trf->ddev) {
2132 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2133 		ret = -ENOMEM;
2134 		goto err_disable_regulator;
2135 	}
2136 
2137 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2138 	nfc_digital_set_drvdata(trf->ddev, trf);
2139 	spi_set_drvdata(spi, trf);
2140 
2141 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2142 
2143 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2144 	pm_runtime_use_autosuspend(trf->dev);
2145 
2146 	ret = trf7970a_startup(trf);
2147 	if (ret)
2148 		goto err_free_ddev;
2149 
2150 	ret = nfc_digital_register_device(trf->ddev);
2151 	if (ret) {
2152 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2153 				ret);
2154 		goto err_shutdown;
2155 	}
2156 
2157 	return 0;
2158 
2159 err_shutdown:
2160 	trf7970a_shutdown(trf);
2161 err_free_ddev:
2162 	nfc_digital_free_device(trf->ddev);
2163 err_disable_regulator:
2164 	regulator_disable(trf->regulator);
2165 err_destroy_lock:
2166 	mutex_destroy(&trf->lock);
2167 	return ret;
2168 }
2169 
2170 static int trf7970a_remove(struct spi_device *spi)
2171 {
2172 	struct trf7970a *trf = spi_get_drvdata(spi);
2173 
2174 	mutex_lock(&trf->lock);
2175 
2176 	trf7970a_shutdown(trf);
2177 
2178 	mutex_unlock(&trf->lock);
2179 
2180 	nfc_digital_unregister_device(trf->ddev);
2181 	nfc_digital_free_device(trf->ddev);
2182 
2183 	regulator_disable(trf->regulator);
2184 
2185 	mutex_destroy(&trf->lock);
2186 
2187 	return 0;
2188 }
2189 
2190 #ifdef CONFIG_PM_SLEEP
2191 static int trf7970a_suspend(struct device *dev)
2192 {
2193 	struct spi_device *spi = to_spi_device(dev);
2194 	struct trf7970a *trf = spi_get_drvdata(spi);
2195 
2196 	dev_dbg(dev, "Suspend\n");
2197 
2198 	mutex_lock(&trf->lock);
2199 
2200 	trf7970a_shutdown(trf);
2201 
2202 	mutex_unlock(&trf->lock);
2203 
2204 	return 0;
2205 }
2206 
2207 static int trf7970a_resume(struct device *dev)
2208 {
2209 	struct spi_device *spi = to_spi_device(dev);
2210 	struct trf7970a *trf = spi_get_drvdata(spi);
2211 	int ret;
2212 
2213 	dev_dbg(dev, "Resume\n");
2214 
2215 	mutex_lock(&trf->lock);
2216 
2217 	ret = trf7970a_startup(trf);
2218 
2219 	mutex_unlock(&trf->lock);
2220 
2221 	return ret;
2222 }
2223 #endif
2224 
2225 #ifdef CONFIG_PM
2226 static int trf7970a_pm_runtime_suspend(struct device *dev)
2227 {
2228 	struct spi_device *spi = to_spi_device(dev);
2229 	struct trf7970a *trf = spi_get_drvdata(spi);
2230 	int ret;
2231 
2232 	dev_dbg(dev, "Runtime suspend\n");
2233 
2234 	mutex_lock(&trf->lock);
2235 
2236 	ret = trf7970a_power_down(trf);
2237 
2238 	mutex_unlock(&trf->lock);
2239 
2240 	return ret;
2241 }
2242 
2243 static int trf7970a_pm_runtime_resume(struct device *dev)
2244 {
2245 	struct spi_device *spi = to_spi_device(dev);
2246 	struct trf7970a *trf = spi_get_drvdata(spi);
2247 	int ret;
2248 
2249 	dev_dbg(dev, "Runtime resume\n");
2250 
2251 	ret = trf7970a_power_up(trf);
2252 	if (!ret)
2253 		pm_runtime_mark_last_busy(dev);
2254 
2255 	return ret;
2256 }
2257 #endif
2258 
2259 static const struct dev_pm_ops trf7970a_pm_ops = {
2260 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2261 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2262 			trf7970a_pm_runtime_resume, NULL)
2263 };
2264 
2265 static const struct of_device_id trf7970a_of_match[] = {
2266 	{ .compatible = "ti,trf7970a", },
2267 	{},
2268 };
2269 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2270 
2271 static const struct spi_device_id trf7970a_id_table[] = {
2272 	{ "trf7970a", 0 },
2273 	{ }
2274 };
2275 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2276 
2277 static struct spi_driver trf7970a_spi_driver = {
2278 	.probe		= trf7970a_probe,
2279 	.remove		= trf7970a_remove,
2280 	.id_table	= trf7970a_id_table,
2281 	.driver		= {
2282 		.name	= "trf7970a",
2283 		.of_match_table = of_match_ptr(trf7970a_of_match),
2284 		.pm	= &trf7970a_pm_ops,
2285 	},
2286 };
2287 
2288 module_spi_driver(trf7970a_spi_driver);
2289 
2290 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2291 MODULE_LICENSE("GPL v2");
2292 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2293