xref: /linux/drivers/nfc/trf7970a.c (revision d257f9bf06129613de539ea71ecea60848b662cd)
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 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
130 
131 #define TRF7970A_FIFO_SIZE			127
132 
133 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
134 #define TRF7970A_TX_MAX				(4096 - 1)
135 
136 #define TRF7970A_WAIT_FOR_TX_IRQ		20
137 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
138 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
139 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
140 
141 /* Guard times for various RF technologies (in us) */
142 #define TRF7970A_GUARD_TIME_NFCA		5000
143 #define TRF7970A_GUARD_TIME_NFCB		5000
144 #define TRF7970A_GUARD_TIME_NFCF		20000
145 #define TRF7970A_GUARD_TIME_15693		1000
146 
147 /* Quirks */
148 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
149  * read continuous command for IRQ Status and Collision Position registers.
150  */
151 #define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
152 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
153 
154 /* Direct commands */
155 #define TRF7970A_CMD_IDLE			0x00
156 #define TRF7970A_CMD_SOFT_INIT			0x03
157 #define TRF7970A_CMD_RF_COLLISION		0x04
158 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
159 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
160 #define TRF7970A_CMD_FIFO_RESET			0x0f
161 #define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
162 #define TRF7970A_CMD_TRANSMIT			0x11
163 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
164 #define TRF7970A_CMD_DELAY_TRANSMIT		0x13
165 #define TRF7970A_CMD_EOF			0x14
166 #define TRF7970A_CMD_CLOSE_SLOT			0x15
167 #define TRF7970A_CMD_BLOCK_RX			0x16
168 #define TRF7970A_CMD_ENABLE_RX			0x17
169 #define TRF7970A_CMD_TEST_INT_RF		0x18
170 #define TRF7970A_CMD_TEST_EXT_RF		0x19
171 #define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
172 
173 /* Bits determining whether its a direct command or register R/W,
174  * whether to use a continuous SPI transaction or not, and the actual
175  * direct cmd opcode or regster address.
176  */
177 #define TRF7970A_CMD_BIT_CTRL			BIT(7)
178 #define TRF7970A_CMD_BIT_RW			BIT(6)
179 #define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
180 #define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
181 
182 /* Registers addresses */
183 #define TRF7970A_CHIP_STATUS_CTRL		0x00
184 #define TRF7970A_ISO_CTRL			0x01
185 #define TRF7970A_ISO14443B_TX_OPTIONS		0x02
186 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
187 #define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
188 #define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
189 #define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
190 #define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
191 #define TRF7970A_RX_WAIT_TIME			0x08
192 #define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
193 #define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
194 #define TRF7970A_REG_IO_CTRL			0x0b
195 #define TRF7970A_IRQ_STATUS			0x0c
196 #define TRF7970A_COLLISION_IRQ_MASK		0x0d
197 #define TRF7970A_COLLISION_POSITION		0x0e
198 #define TRF7970A_RSSI_OSC_STATUS		0x0f
199 #define TRF7970A_SPECIAL_FCN_REG1		0x10
200 #define TRF7970A_SPECIAL_FCN_REG2		0x11
201 #define TRF7970A_RAM1				0x12
202 #define TRF7970A_RAM2				0x13
203 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
204 #define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
205 #define TRF7970A_NFCID1				0x17
206 #define TRF7970A_NFC_TARGET_LEVEL		0x18
207 #define TRF79070A_NFC_TARGET_PROTOCOL		0x19
208 #define TRF7970A_TEST_REGISTER1			0x1a
209 #define TRF7970A_TEST_REGISTER2			0x1b
210 #define TRF7970A_FIFO_STATUS			0x1c
211 #define TRF7970A_TX_LENGTH_BYTE1		0x1d
212 #define TRF7970A_TX_LENGTH_BYTE2		0x1e
213 #define TRF7970A_FIFO_IO_REGISTER		0x1f
214 
215 /* Chip Status Control Register Bits */
216 #define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
217 #define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
218 #define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
219 #define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
220 #define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
221 #define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
222 #define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
223 #define TRF7970A_CHIP_STATUS_STBY		BIT(7)
224 
225 /* ISO Control Register Bits */
226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
227 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
228 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
231 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
232 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
234 #define TRF7970A_ISO_CTRL_14443A_106		0x08
235 #define TRF7970A_ISO_CTRL_14443A_212		0x09
236 #define TRF7970A_ISO_CTRL_14443A_424		0x0a
237 #define TRF7970A_ISO_CTRL_14443A_848		0x0b
238 #define TRF7970A_ISO_CTRL_14443B_106		0x0c
239 #define TRF7970A_ISO_CTRL_14443B_212		0x0d
240 #define TRF7970A_ISO_CTRL_14443B_424		0x0e
241 #define TRF7970A_ISO_CTRL_14443B_848		0x0f
242 #define TRF7970A_ISO_CTRL_FELICA_212		0x1a
243 #define TRF7970A_ISO_CTRL_FELICA_424		0x1b
244 #define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
245 #define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
246 #define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
247 #define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
248 #define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
249 #define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
250 #define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
251 #define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
252 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
253 #define TRF7970A_ISO_CTRL_RFID			BIT(5)
254 #define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
255 #define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
256 
257 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
258 
259 /* Modulator and SYS_CLK Control Register Bits */
260 #define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
261 #define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
262 #define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
263 #define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
264 #define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
265 #define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
266 #define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
267 #define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
268 #define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
269 #define TRF7970A_MODULATOR_EN_ANA		BIT(3)
270 #define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
271 #define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
272 #define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
273 #define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
274 #define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
275 #define TRF7970A_MODULATOR_EN_OOK		BIT(6)
276 #define TRF7970A_MODULATOR_27MHZ		BIT(7)
277 
278 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
279 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
281 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
282 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
285 #define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
286 #define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
287 #define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
288 
289 #define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
290 #define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
291 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
292 #define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
293 
294 /* IRQ Status Register Bits */
295 #define TRF7970A_IRQ_STATUS_NORESP		BIT(0)	/* ISO15693 only */
296 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
297 #define TRF7970A_IRQ_STATUS_COL			BIT(1)
298 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
299 #define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
300 #define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
301 #define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
302 #define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
303 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
304 #define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
305 #define TRF7970A_IRQ_STATUS_SRX			BIT(6)
306 #define TRF7970A_IRQ_STATUS_TX			BIT(7)
307 
308 #define TRF7970A_IRQ_STATUS_ERROR				\
309 		(TRF7970A_IRQ_STATUS_COL |			\
310 		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
311 		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
312 		 TRF7970A_IRQ_STATUS_CRC_ERROR)
313 
314 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
315 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
316 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
317 
318 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
319 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
320 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
321 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
322 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
323 #define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
324 
325 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
326 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
333 
334 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
335 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
336 
337 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
338 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
339 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
340 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
341 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
342 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
343 
344 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
345 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
346 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
347 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
349 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
350 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
351 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
352 
353 #define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
354 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
355 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
356 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
357 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
358 
359 #define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
360 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
361 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
362 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
363 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
364 
365 #define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
366 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
367 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
368 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
369 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
370 
371 #define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
372 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
373 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
374 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
375 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
376 
377 #define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
378 
379 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
380 #define NFC_T2T_CMD_READ			0x30
381 
382 /* ISO 15693 commands codes */
383 #define ISO15693_CMD_INVENTORY			0x01
384 #define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
385 #define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
386 #define ISO15693_CMD_LOCK_BLOCK			0x22
387 #define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
388 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
389 #define ISO15693_CMD_SELECT			0x25
390 #define ISO15693_CMD_RESET_TO_READY		0x26
391 #define ISO15693_CMD_WRITE_AFI			0x27
392 #define ISO15693_CMD_LOCK_AFI			0x28
393 #define ISO15693_CMD_WRITE_DSFID		0x29
394 #define ISO15693_CMD_LOCK_DSFID			0x2a
395 #define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
396 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
397 
398 /* ISO 15693 request and response flags */
399 #define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
400 #define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
401 #define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
402 #define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
403 #define ISO15693_REQ_FLAG_SELECT		BIT(4)
404 #define ISO15693_REQ_FLAG_AFI			BIT(4)
405 #define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
406 #define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
407 #define ISO15693_REQ_FLAG_OPTION		BIT(6)
408 
409 #define ISO15693_REQ_FLAG_SPEED_MASK \
410 		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
411 
412 enum trf7970a_state {
413 	TRF7970A_ST_PWR_OFF,
414 	TRF7970A_ST_RF_OFF,
415 	TRF7970A_ST_IDLE,
416 	TRF7970A_ST_IDLE_RX_BLOCKED,
417 	TRF7970A_ST_WAIT_FOR_TX_FIFO,
418 	TRF7970A_ST_WAIT_FOR_RX_DATA,
419 	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
420 	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
421 	TRF7970A_ST_LISTENING,
422 	TRF7970A_ST_LISTENING_MD,
423 	TRF7970A_ST_MAX
424 };
425 
426 struct trf7970a {
427 	enum trf7970a_state		state;
428 	struct device			*dev;
429 	struct spi_device		*spi;
430 	struct regulator		*regulator;
431 	struct nfc_digital_dev		*ddev;
432 	u32				quirks;
433 	bool				is_initiator;
434 	bool				aborting;
435 	struct sk_buff			*tx_skb;
436 	struct sk_buff			*rx_skb;
437 	nfc_digital_cmd_complete_t	cb;
438 	void				*cb_arg;
439 	u8				chip_status_ctrl;
440 	u8				iso_ctrl;
441 	u8				iso_ctrl_tech;
442 	u8				modulator_sys_clk_ctrl;
443 	u8				special_fcn_reg1;
444 	u8				io_ctrl;
445 	unsigned int			guard_time;
446 	int				technology;
447 	int				framing;
448 	u8				md_rf_tech;
449 	u8				tx_cmd;
450 	bool				issue_eof;
451 	struct gpio_desc		*en_gpiod;
452 	struct gpio_desc		*en2_gpiod;
453 	struct mutex			lock;
454 	unsigned int			timeout;
455 	bool				ignore_timeout;
456 	struct delayed_work		timeout_work;
457 };
458 
459 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
460 {
461 	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
462 	int ret;
463 
464 	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
465 
466 	ret = spi_write(trf->spi, &cmd, 1);
467 	if (ret)
468 		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
469 			ret);
470 	return ret;
471 }
472 
473 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
474 {
475 	u8 addr = TRF7970A_CMD_BIT_RW | reg;
476 	int ret;
477 
478 	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
479 	if (ret)
480 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
481 			ret);
482 
483 	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
484 
485 	return ret;
486 }
487 
488 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
489 			      size_t len)
490 {
491 	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
492 	struct spi_transfer t[2];
493 	struct spi_message m;
494 	int ret;
495 
496 	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
497 
498 	spi_message_init(&m);
499 
500 	memset(&t, 0, sizeof(t));
501 
502 	t[0].tx_buf = &addr;
503 	t[0].len = sizeof(addr);
504 	spi_message_add_tail(&t[0], &m);
505 
506 	t[1].rx_buf = buf;
507 	t[1].len = len;
508 	spi_message_add_tail(&t[1], &m);
509 
510 	ret = spi_sync(trf->spi, &m);
511 	if (ret)
512 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
513 			ret);
514 	return ret;
515 }
516 
517 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
518 {
519 	u8 buf[2] = { reg, val };
520 	int ret;
521 
522 	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
523 
524 	ret = spi_write(trf->spi, buf, 2);
525 	if (ret)
526 		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
527 			buf[0], buf[1], ret);
528 
529 	return ret;
530 }
531 
532 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
533 {
534 	int ret;
535 	u8 buf[2];
536 	u8 addr;
537 
538 	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
539 
540 	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
541 		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
542 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
543 	} else {
544 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
545 	}
546 
547 	if (ret)
548 		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
549 			__func__, ret);
550 	else
551 		*status = buf[0];
552 
553 	return ret;
554 }
555 
556 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
557 {
558 	int ret;
559 	u8 buf[2];
560 	u8 addr;
561 
562 	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
563 	       TRF7970A_CMD_BIT_CONTINUOUS;
564 
565 	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
566 	if (ret)
567 		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
568 			__func__, ret);
569 	else
570 		*target_proto = buf[0];
571 
572 	return ret;
573 }
574 
575 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
576 {
577 	int ret;
578 	u8 target_proto, tech;
579 
580 	ret = trf7970a_read_target_proto(trf, &target_proto);
581 	if (ret)
582 		return ret;
583 
584 	switch (target_proto) {
585 	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
586 		tech = NFC_DIGITAL_RF_TECH_106A;
587 		break;
588 	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
589 		tech = NFC_DIGITAL_RF_TECH_106B;
590 		break;
591 	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
592 		tech = NFC_DIGITAL_RF_TECH_212F;
593 		break;
594 	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
595 		tech = NFC_DIGITAL_RF_TECH_424F;
596 		break;
597 	default:
598 		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
599 			__func__, target_proto);
600 		return -EIO;
601 	}
602 
603 	*rf_tech = tech;
604 
605 	return ret;
606 }
607 
608 static void trf7970a_send_upstream(struct trf7970a *trf)
609 {
610 	dev_kfree_skb_any(trf->tx_skb);
611 	trf->tx_skb = NULL;
612 
613 	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
614 		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
615 				     16, 1, trf->rx_skb->data, trf->rx_skb->len,
616 				     false);
617 
618 	trf->state = TRF7970A_ST_IDLE;
619 
620 	if (trf->aborting) {
621 		dev_dbg(trf->dev, "Abort process complete\n");
622 
623 		if (!IS_ERR(trf->rx_skb)) {
624 			kfree_skb(trf->rx_skb);
625 			trf->rx_skb = ERR_PTR(-ECANCELED);
626 		}
627 
628 		trf->aborting = false;
629 	}
630 
631 	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
632 
633 	trf->rx_skb = NULL;
634 }
635 
636 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
637 {
638 	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
639 
640 	cancel_delayed_work(&trf->timeout_work);
641 
642 	kfree_skb(trf->rx_skb);
643 	trf->rx_skb = ERR_PTR(errno);
644 
645 	trf7970a_send_upstream(trf);
646 }
647 
648 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
649 			     unsigned int len, u8 *prefix,
650 			     unsigned int prefix_len)
651 {
652 	struct spi_transfer t[2];
653 	struct spi_message m;
654 	unsigned int timeout;
655 	int ret;
656 
657 	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
658 			     16, 1, skb->data, len, false);
659 
660 	spi_message_init(&m);
661 
662 	memset(&t, 0, sizeof(t));
663 
664 	t[0].tx_buf = prefix;
665 	t[0].len = prefix_len;
666 	spi_message_add_tail(&t[0], &m);
667 
668 	t[1].tx_buf = skb->data;
669 	t[1].len = len;
670 	spi_message_add_tail(&t[1], &m);
671 
672 	ret = spi_sync(trf->spi, &m);
673 	if (ret) {
674 		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
675 			ret);
676 		return ret;
677 	}
678 
679 	skb_pull(skb, len);
680 
681 	if (skb->len > 0) {
682 		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
683 		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
684 	} else {
685 		if (trf->issue_eof) {
686 			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
687 			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
688 		} else {
689 			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
690 
691 			if (!trf->timeout)
692 				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
693 			else
694 				timeout = trf->timeout;
695 		}
696 	}
697 
698 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
699 		trf->state);
700 
701 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
702 
703 	return 0;
704 }
705 
706 static void trf7970a_fill_fifo(struct trf7970a *trf)
707 {
708 	struct sk_buff *skb = trf->tx_skb;
709 	unsigned int len;
710 	int ret;
711 	u8 fifo_bytes;
712 	u8 prefix;
713 
714 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
715 	if (ret) {
716 		trf7970a_send_err_upstream(trf, ret);
717 		return;
718 	}
719 
720 	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
721 
722 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
723 
724 	/* Calculate how much more data can be written to the fifo */
725 	len = TRF7970A_FIFO_SIZE - fifo_bytes;
726 	if (!len) {
727 		schedule_delayed_work(&trf->timeout_work,
728 			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
729 		return;
730 	}
731 
732 	len = min(skb->len, len);
733 
734 	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
735 
736 	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
737 	if (ret)
738 		trf7970a_send_err_upstream(trf, ret);
739 }
740 
741 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
742 {
743 	struct sk_buff *skb = trf->rx_skb;
744 	int ret;
745 	u8 fifo_bytes;
746 
747 	if (status & TRF7970A_IRQ_STATUS_ERROR) {
748 		trf7970a_send_err_upstream(trf, -EIO);
749 		return;
750 	}
751 
752 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
753 	if (ret) {
754 		trf7970a_send_err_upstream(trf, ret);
755 		return;
756 	}
757 
758 	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
759 
760 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
761 
762 	if (!fifo_bytes)
763 		goto no_rx_data;
764 
765 	if (fifo_bytes > skb_tailroom(skb)) {
766 		skb = skb_copy_expand(skb, skb_headroom(skb),
767 				      max_t(int, fifo_bytes,
768 					    TRF7970A_RX_SKB_ALLOC_SIZE),
769 				      GFP_KERNEL);
770 		if (!skb) {
771 			trf7970a_send_err_upstream(trf, -ENOMEM);
772 			return;
773 		}
774 
775 		kfree_skb(trf->rx_skb);
776 		trf->rx_skb = skb;
777 	}
778 
779 	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
780 				 skb_put(skb, fifo_bytes), fifo_bytes);
781 	if (ret) {
782 		trf7970a_send_err_upstream(trf, ret);
783 		return;
784 	}
785 
786 	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
787 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
788 	    (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
789 		skb->data[0] >>= 4;
790 		status = TRF7970A_IRQ_STATUS_SRX;
791 	} else {
792 		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
793 
794 		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
795 		if (ret) {
796 			trf7970a_send_err_upstream(trf, ret);
797 			return;
798 		}
799 
800 		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
801 
802 		/* If there are bytes in the FIFO, set status to '0' so
803 		 * the if stmt below doesn't fire and the driver will wait
804 		 * for the trf7970a to generate another RX interrupt.
805 		 */
806 		if (fifo_bytes)
807 			status = 0;
808 	}
809 
810 no_rx_data:
811 	if (status == TRF7970A_IRQ_STATUS_SRX) {	/* Receive complete */
812 		trf7970a_send_upstream(trf);
813 		return;
814 	}
815 
816 	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
817 		TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
818 
819 	schedule_delayed_work(&trf->timeout_work,
820 			   msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
821 }
822 
823 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
824 {
825 	struct trf7970a *trf = dev_id;
826 	int ret;
827 	u8 status, fifo_bytes, iso_ctrl;
828 
829 	mutex_lock(&trf->lock);
830 
831 	if (trf->state == TRF7970A_ST_RF_OFF) {
832 		mutex_unlock(&trf->lock);
833 		return IRQ_NONE;
834 	}
835 
836 	ret = trf7970a_read_irqstatus(trf, &status);
837 	if (ret) {
838 		mutex_unlock(&trf->lock);
839 		return IRQ_NONE;
840 	}
841 
842 	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
843 		status);
844 
845 	if (!status) {
846 		mutex_unlock(&trf->lock);
847 		return IRQ_NONE;
848 	}
849 
850 	switch (trf->state) {
851 	case TRF7970A_ST_IDLE:
852 	case TRF7970A_ST_IDLE_RX_BLOCKED:
853 		/* If initiator and getting interrupts caused by RF noise,
854 		 * turn off the receiver to avoid unnecessary interrupts.
855 		 * It will be turned back on in trf7970a_send_cmd() when
856 		 * the next command is issued.
857 		 */
858 		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
859 			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
860 			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
861 		}
862 
863 		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
864 		break;
865 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
866 		if (status & TRF7970A_IRQ_STATUS_TX) {
867 			trf->ignore_timeout =
868 			    !cancel_delayed_work(&trf->timeout_work);
869 			trf7970a_fill_fifo(trf);
870 		} else {
871 			trf7970a_send_err_upstream(trf, -EIO);
872 		}
873 		break;
874 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
875 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
876 		if (status & TRF7970A_IRQ_STATUS_SRX) {
877 			trf->ignore_timeout =
878 			    !cancel_delayed_work(&trf->timeout_work);
879 			trf7970a_drain_fifo(trf, status);
880 		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
881 			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
882 					    &fifo_bytes);
883 
884 			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
885 
886 			if (ret)
887 				trf7970a_send_err_upstream(trf, ret);
888 			else if (!fifo_bytes)
889 				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
890 		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
891 			   (!trf->is_initiator &&
892 			    (status == (TRF7970A_IRQ_STATUS_TX |
893 					TRF7970A_IRQ_STATUS_NFC_RF)))) {
894 			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
895 
896 			if (!trf->timeout) {
897 				trf->ignore_timeout =
898 				    !cancel_delayed_work(&trf->timeout_work);
899 				trf->rx_skb = ERR_PTR(0);
900 				trf7970a_send_upstream(trf);
901 				break;
902 			}
903 
904 			if (trf->is_initiator)
905 				break;
906 
907 			iso_ctrl = trf->iso_ctrl;
908 
909 			switch (trf->framing) {
910 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
911 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
912 				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
913 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
914 				break;
915 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
916 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
917 				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
918 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
919 				break;
920 			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
921 				ret = trf7970a_write(trf,
922 					 TRF7970A_SPECIAL_FCN_REG1,
923 					 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
924 				if (ret)
925 					goto err_unlock_exit;
926 
927 				trf->special_fcn_reg1 =
928 				    TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
929 				break;
930 			default:
931 				break;
932 			}
933 
934 			if (iso_ctrl != trf->iso_ctrl) {
935 				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
936 						     iso_ctrl);
937 				if (ret)
938 					goto err_unlock_exit;
939 
940 				trf->iso_ctrl = iso_ctrl;
941 			}
942 		} else {
943 			trf7970a_send_err_upstream(trf, -EIO);
944 		}
945 		break;
946 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
947 		if (status != TRF7970A_IRQ_STATUS_TX)
948 			trf7970a_send_err_upstream(trf, -EIO);
949 		break;
950 	case TRF7970A_ST_LISTENING:
951 		if (status & TRF7970A_IRQ_STATUS_SRX) {
952 			trf->ignore_timeout =
953 			    !cancel_delayed_work(&trf->timeout_work);
954 			trf7970a_drain_fifo(trf, status);
955 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
956 			trf7970a_send_err_upstream(trf, -EIO);
957 		}
958 		break;
959 	case TRF7970A_ST_LISTENING_MD:
960 		if (status & TRF7970A_IRQ_STATUS_SRX) {
961 			trf->ignore_timeout =
962 			    !cancel_delayed_work(&trf->timeout_work);
963 
964 			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
965 			if (ret) {
966 				trf7970a_send_err_upstream(trf, ret);
967 			} else {
968 				trf->state = TRF7970A_ST_LISTENING;
969 				trf7970a_drain_fifo(trf, status);
970 			}
971 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
972 			trf7970a_send_err_upstream(trf, -EIO);
973 		}
974 		break;
975 	default:
976 		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
977 			__func__, trf->state);
978 	}
979 
980 err_unlock_exit:
981 	mutex_unlock(&trf->lock);
982 	return IRQ_HANDLED;
983 }
984 
985 static void trf7970a_issue_eof(struct trf7970a *trf)
986 {
987 	int ret;
988 
989 	dev_dbg(trf->dev, "Issuing EOF\n");
990 
991 	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
992 	if (ret)
993 		trf7970a_send_err_upstream(trf, ret);
994 
995 	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
996 	if (ret)
997 		trf7970a_send_err_upstream(trf, ret);
998 
999 	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1000 
1001 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1002 		trf->timeout, trf->state);
1003 
1004 	schedule_delayed_work(&trf->timeout_work,
1005 			      msecs_to_jiffies(trf->timeout));
1006 }
1007 
1008 static void trf7970a_timeout_work_handler(struct work_struct *work)
1009 {
1010 	struct trf7970a *trf = container_of(work, struct trf7970a,
1011 					    timeout_work.work);
1012 
1013 	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1014 		trf->state, trf->ignore_timeout);
1015 
1016 	mutex_lock(&trf->lock);
1017 
1018 	if (trf->ignore_timeout)
1019 		trf->ignore_timeout = false;
1020 	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1021 		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1022 	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1023 		trf7970a_issue_eof(trf);
1024 	else
1025 		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1026 
1027 	mutex_unlock(&trf->lock);
1028 }
1029 
1030 static int trf7970a_init(struct trf7970a *trf)
1031 {
1032 	int ret;
1033 
1034 	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1035 
1036 	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1037 	if (ret)
1038 		goto err_out;
1039 
1040 	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1041 	if (ret)
1042 		goto err_out;
1043 
1044 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1045 			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1046 	if (ret)
1047 		goto err_out;
1048 
1049 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1050 	if (ret)
1051 		goto err_out;
1052 
1053 	usleep_range(1000, 2000);
1054 
1055 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1056 
1057 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1058 			     trf->modulator_sys_clk_ctrl);
1059 	if (ret)
1060 		goto err_out;
1061 
1062 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1063 			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1064 			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1065 	if (ret)
1066 		goto err_out;
1067 
1068 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1069 	if (ret)
1070 		goto err_out;
1071 
1072 	trf->special_fcn_reg1 = 0;
1073 
1074 	trf->iso_ctrl = 0xff;
1075 	return 0;
1076 
1077 err_out:
1078 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1079 	return ret;
1080 }
1081 
1082 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1083 {
1084 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1085 	    (trf->state == TRF7970A_ST_RF_OFF))
1086 		return;
1087 
1088 	dev_dbg(trf->dev, "Switching rf off\n");
1089 
1090 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1091 
1092 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1093 
1094 	trf->aborting = false;
1095 	trf->state = TRF7970A_ST_RF_OFF;
1096 
1097 	pm_runtime_mark_last_busy(trf->dev);
1098 	pm_runtime_put_autosuspend(trf->dev);
1099 }
1100 
1101 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1102 {
1103 	int ret;
1104 
1105 	dev_dbg(trf->dev, "Switching rf on\n");
1106 
1107 	pm_runtime_get_sync(trf->dev);
1108 
1109 	if (trf->state != TRF7970A_ST_RF_OFF) {	/* Power on, RF off */
1110 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1111 			trf->state);
1112 		return -EINVAL;
1113 	}
1114 
1115 	ret = trf7970a_init(trf);
1116 	if (ret) {
1117 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1118 		return ret;
1119 	}
1120 
1121 	trf->state = TRF7970A_ST_IDLE;
1122 
1123 	return 0;
1124 }
1125 
1126 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1127 {
1128 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1129 	int ret = 0;
1130 
1131 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1132 
1133 	mutex_lock(&trf->lock);
1134 
1135 	if (on) {
1136 		switch (trf->state) {
1137 		case TRF7970A_ST_PWR_OFF:
1138 		case TRF7970A_ST_RF_OFF:
1139 			ret = trf7970a_switch_rf_on(trf);
1140 			break;
1141 		case TRF7970A_ST_IDLE:
1142 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1143 			break;
1144 		default:
1145 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1146 				__func__, trf->state, on);
1147 			trf7970a_switch_rf_off(trf);
1148 			ret = -EINVAL;
1149 		}
1150 	} else {
1151 		switch (trf->state) {
1152 		case TRF7970A_ST_PWR_OFF:
1153 		case TRF7970A_ST_RF_OFF:
1154 			break;
1155 		default:
1156 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1157 				__func__, trf->state, on);
1158 			ret = -EINVAL;
1159 			/* FALLTHROUGH */
1160 		case TRF7970A_ST_IDLE:
1161 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1162 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1163 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1164 			trf7970a_switch_rf_off(trf);
1165 		}
1166 	}
1167 
1168 	mutex_unlock(&trf->lock);
1169 	return ret;
1170 }
1171 
1172 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1173 {
1174 	int ret = 0;
1175 
1176 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1177 
1178 	switch (tech) {
1179 	case NFC_DIGITAL_RF_TECH_106A:
1180 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1181 		trf->modulator_sys_clk_ctrl =
1182 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1183 		    TRF7970A_MODULATOR_DEPTH_OOK;
1184 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1185 		break;
1186 	case NFC_DIGITAL_RF_TECH_106B:
1187 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1188 		trf->modulator_sys_clk_ctrl =
1189 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1190 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1191 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1192 		break;
1193 	case NFC_DIGITAL_RF_TECH_212F:
1194 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1195 		trf->modulator_sys_clk_ctrl =
1196 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1197 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1198 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1199 		break;
1200 	case NFC_DIGITAL_RF_TECH_424F:
1201 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1202 		trf->modulator_sys_clk_ctrl =
1203 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1204 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1205 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1206 		break;
1207 	case NFC_DIGITAL_RF_TECH_ISO15693:
1208 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1209 		trf->modulator_sys_clk_ctrl =
1210 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1211 		    TRF7970A_MODULATOR_DEPTH_OOK;
1212 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1213 		break;
1214 	default:
1215 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1216 		return -EINVAL;
1217 	}
1218 
1219 	trf->technology = tech;
1220 
1221 	/* If in initiator mode and not changing the RF tech due to a
1222 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1223 	 * trf7970a_init()), clear the NFC Target Detection Level register
1224 	 * due to erratum.
1225 	 */
1226 	if (trf->iso_ctrl == 0xff)
1227 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1228 
1229 	return ret;
1230 }
1231 
1232 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1233 {
1234 	int ret;
1235 	u8 rssi;
1236 
1237 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1238 			     trf->chip_status_ctrl |
1239 			     TRF7970A_CHIP_STATUS_REC_ON);
1240 	if (ret)
1241 		return ret;
1242 
1243 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1244 	if (ret)
1245 		return ret;
1246 
1247 	usleep_range(50, 60);
1248 
1249 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1250 	if (ret)
1251 		return ret;
1252 
1253 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1254 			     trf->chip_status_ctrl);
1255 	if (ret)
1256 		return ret;
1257 
1258 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1259 		*is_rf_field = true;
1260 	else
1261 		*is_rf_field = false;
1262 
1263 	return 0;
1264 }
1265 
1266 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1267 {
1268 	u8 iso_ctrl = trf->iso_ctrl_tech;
1269 	bool is_rf_field = false;
1270 	int ret;
1271 
1272 	dev_dbg(trf->dev, "framing: %d\n", framing);
1273 
1274 	switch (framing) {
1275 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1276 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1277 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1278 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1279 		break;
1280 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1281 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1282 	case NFC_DIGITAL_FRAMING_NFCB:
1283 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1284 	case NFC_DIGITAL_FRAMING_NFCF:
1285 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1286 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1287 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1288 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1289 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1290 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1291 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1292 		break;
1293 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1294 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1295 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1296 		break;
1297 	default:
1298 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1299 		return -EINVAL;
1300 	}
1301 
1302 	trf->framing = framing;
1303 
1304 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1305 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1306 		if (ret)
1307 			return ret;
1308 
1309 		if (is_rf_field)
1310 			return -EBUSY;
1311 	}
1312 
1313 	if (iso_ctrl != trf->iso_ctrl) {
1314 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1315 		if (ret)
1316 			return ret;
1317 
1318 		trf->iso_ctrl = iso_ctrl;
1319 
1320 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1321 				     trf->modulator_sys_clk_ctrl);
1322 		if (ret)
1323 			return ret;
1324 	}
1325 
1326 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1327 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1328 				     trf->chip_status_ctrl |
1329 				     TRF7970A_CHIP_STATUS_RF_ON);
1330 		if (ret)
1331 			return ret;
1332 
1333 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1334 
1335 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1336 	}
1337 
1338 	return 0;
1339 }
1340 
1341 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1342 				    int param)
1343 {
1344 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1345 	int ret;
1346 
1347 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1348 
1349 	mutex_lock(&trf->lock);
1350 
1351 	trf->is_initiator = true;
1352 
1353 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1354 	    (trf->state == TRF7970A_ST_RF_OFF)) {
1355 		ret = trf7970a_switch_rf_on(trf);
1356 		if (ret)
1357 			goto err_unlock;
1358 	}
1359 
1360 	switch (type) {
1361 	case NFC_DIGITAL_CONFIG_RF_TECH:
1362 		ret = trf7970a_in_config_rf_tech(trf, param);
1363 		break;
1364 	case NFC_DIGITAL_CONFIG_FRAMING:
1365 		ret = trf7970a_in_config_framing(trf, param);
1366 		break;
1367 	default:
1368 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1369 		ret = -EINVAL;
1370 	}
1371 
1372 err_unlock:
1373 	mutex_unlock(&trf->lock);
1374 	return ret;
1375 }
1376 
1377 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1378 {
1379 	switch (cmd) {
1380 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1381 	case ISO15693_CMD_LOCK_BLOCK:
1382 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1383 	case ISO15693_CMD_WRITE_AFI:
1384 	case ISO15693_CMD_LOCK_AFI:
1385 	case ISO15693_CMD_WRITE_DSFID:
1386 	case ISO15693_CMD_LOCK_DSFID:
1387 		return 1;
1388 		break;
1389 	default:
1390 		return 0;
1391 	}
1392 }
1393 
1394 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1395 {
1396 	u8 *req = skb->data;
1397 	u8 special_fcn_reg1, iso_ctrl;
1398 	int ret;
1399 
1400 	trf->issue_eof = false;
1401 
1402 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1403 	 * special functions register 1 is cleared; otherwise, its a write or
1404 	 * sector select command and '4_bit_RX' must be set.
1405 	 *
1406 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1407 	 * what speed to use.  Also, remember if the OPTION flag is set on
1408 	 * a Type 5 write or lock command so the driver will know that it
1409 	 * has to send an EOF in order to get a response.
1410 	 */
1411 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1412 	    (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1413 		if (req[0] == NFC_T2T_CMD_READ)
1414 			special_fcn_reg1 = 0;
1415 		else
1416 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1417 
1418 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1419 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1420 					     special_fcn_reg1);
1421 			if (ret)
1422 				return ret;
1423 
1424 			trf->special_fcn_reg1 = special_fcn_reg1;
1425 		}
1426 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1427 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1428 
1429 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1430 		case 0x00:
1431 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1432 			break;
1433 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1434 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1435 			break;
1436 		case ISO15693_REQ_FLAG_DATA_RATE:
1437 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1438 			break;
1439 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1440 		      ISO15693_REQ_FLAG_DATA_RATE):
1441 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1442 			break;
1443 		}
1444 
1445 		if (iso_ctrl != trf->iso_ctrl) {
1446 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1447 			if (ret)
1448 				return ret;
1449 
1450 			trf->iso_ctrl = iso_ctrl;
1451 		}
1452 
1453 		if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1454 		    trf7970a_is_iso15693_write_or_lock(req[1]) &&
1455 		    (req[0] & ISO15693_REQ_FLAG_OPTION))
1456 			trf->issue_eof = true;
1457 	}
1458 
1459 	return 0;
1460 }
1461 
1462 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1463 			     struct sk_buff *skb, u16 timeout,
1464 			     nfc_digital_cmd_complete_t cb, void *arg)
1465 {
1466 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1467 	u8 prefix[5];
1468 	unsigned int len;
1469 	int ret;
1470 	u8 status;
1471 
1472 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1473 		trf->state, timeout, skb->len);
1474 
1475 	if (skb->len > TRF7970A_TX_MAX)
1476 		return -EINVAL;
1477 
1478 	mutex_lock(&trf->lock);
1479 
1480 	if ((trf->state != TRF7970A_ST_IDLE) &&
1481 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1482 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1483 			trf->state);
1484 		ret = -EIO;
1485 		goto out_err;
1486 	}
1487 
1488 	if (trf->aborting) {
1489 		dev_dbg(trf->dev, "Abort process complete\n");
1490 		trf->aborting = false;
1491 		ret = -ECANCELED;
1492 		goto out_err;
1493 	}
1494 
1495 	if (timeout) {
1496 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1497 						 GFP_KERNEL);
1498 		if (!trf->rx_skb) {
1499 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1500 			ret = -ENOMEM;
1501 			goto out_err;
1502 		}
1503 	}
1504 
1505 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1506 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1507 		if (ret)
1508 			goto out_err;
1509 
1510 		trf->state = TRF7970A_ST_IDLE;
1511 	}
1512 
1513 	if (trf->is_initiator) {
1514 		ret = trf7970a_per_cmd_config(trf, skb);
1515 		if (ret)
1516 			goto out_err;
1517 	}
1518 
1519 	trf->ddev = ddev;
1520 	trf->tx_skb = skb;
1521 	trf->cb = cb;
1522 	trf->cb_arg = arg;
1523 	trf->timeout = timeout;
1524 	trf->ignore_timeout = false;
1525 
1526 	len = skb->len;
1527 
1528 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1529 	 * on what the current framing is, the address of the TX length byte 1
1530 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1531 	 * That totals 5 bytes.
1532 	 */
1533 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1534 	    TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1535 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1536 	    TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1537 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1538 
1539 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1540 		prefix[3] = 0x00;
1541 		prefix[4] = 0x0f;	/* 7 bits */
1542 	} else {
1543 		prefix[3] = (len & 0xf00) >> 4;
1544 		prefix[3] |= ((len & 0xf0) >> 4);
1545 		prefix[4] = ((len & 0x0f) << 4);
1546 	}
1547 
1548 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1549 
1550 	/* Clear possible spurious interrupt */
1551 	ret = trf7970a_read_irqstatus(trf, &status);
1552 	if (ret)
1553 		goto out_err;
1554 
1555 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1556 	if (ret) {
1557 		kfree_skb(trf->rx_skb);
1558 		trf->rx_skb = NULL;
1559 	}
1560 
1561 out_err:
1562 	mutex_unlock(&trf->lock);
1563 	return ret;
1564 }
1565 
1566 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1567 {
1568 	int ret = 0;
1569 
1570 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1571 
1572 	switch (tech) {
1573 	case NFC_DIGITAL_RF_TECH_106A:
1574 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1575 		    TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1576 		trf->modulator_sys_clk_ctrl =
1577 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1578 		    TRF7970A_MODULATOR_DEPTH_OOK;
1579 		break;
1580 	case NFC_DIGITAL_RF_TECH_212F:
1581 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1582 		    TRF7970A_ISO_CTRL_NFC_NFCF_212;
1583 		trf->modulator_sys_clk_ctrl =
1584 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1585 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1586 		break;
1587 	case NFC_DIGITAL_RF_TECH_424F:
1588 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1589 		    TRF7970A_ISO_CTRL_NFC_NFCF_424;
1590 		trf->modulator_sys_clk_ctrl =
1591 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1592 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1593 		break;
1594 	default:
1595 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1596 		return -EINVAL;
1597 	}
1598 
1599 	trf->technology = tech;
1600 
1601 	/* Normally we write the ISO_CTRL register in
1602 	 * trf7970a_tg_config_framing() because the framing can change
1603 	 * the value written.  However, when sending a PSL RES,
1604 	 * digital_tg_send_psl_res_complete() doesn't call
1605 	 * trf7970a_tg_config_framing() so we must write the register
1606 	 * here.
1607 	 */
1608 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1609 	    (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1610 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1611 				     trf->iso_ctrl_tech);
1612 
1613 		trf->iso_ctrl = trf->iso_ctrl_tech;
1614 	}
1615 
1616 	return ret;
1617 }
1618 
1619 /* Since this is a target routine, several of the framing calls are
1620  * made between receiving the request and sending the response so they
1621  * should take effect until after the response is sent.  This is accomplished
1622  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1623  * handler.
1624  */
1625 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1626 {
1627 	u8 iso_ctrl = trf->iso_ctrl_tech;
1628 	int ret;
1629 
1630 	dev_dbg(trf->dev, "framing: %d\n", framing);
1631 
1632 	switch (framing) {
1633 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1634 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1635 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1636 		break;
1637 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1638 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1639 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1640 		/* These ones are applied in the interrupt handler */
1641 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1642 		break;
1643 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1644 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1645 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1646 		break;
1647 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1648 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1649 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1650 		break;
1651 	default:
1652 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1653 		return -EINVAL;
1654 	}
1655 
1656 	trf->framing = framing;
1657 
1658 	if (iso_ctrl != trf->iso_ctrl) {
1659 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1660 		if (ret)
1661 			return ret;
1662 
1663 		trf->iso_ctrl = iso_ctrl;
1664 
1665 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1666 				     trf->modulator_sys_clk_ctrl);
1667 		if (ret)
1668 			return ret;
1669 	}
1670 
1671 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1672 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1673 				     trf->chip_status_ctrl |
1674 				     TRF7970A_CHIP_STATUS_RF_ON);
1675 		if (ret)
1676 			return ret;
1677 
1678 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1679 	}
1680 
1681 	return 0;
1682 }
1683 
1684 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1685 				    int param)
1686 {
1687 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1688 	int ret;
1689 
1690 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1691 
1692 	mutex_lock(&trf->lock);
1693 
1694 	trf->is_initiator = false;
1695 
1696 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1697 	    (trf->state == TRF7970A_ST_RF_OFF)) {
1698 		ret = trf7970a_switch_rf_on(trf);
1699 		if (ret)
1700 			goto err_unlock;
1701 	}
1702 
1703 	switch (type) {
1704 	case NFC_DIGITAL_CONFIG_RF_TECH:
1705 		ret = trf7970a_tg_config_rf_tech(trf, param);
1706 		break;
1707 	case NFC_DIGITAL_CONFIG_FRAMING:
1708 		ret = trf7970a_tg_config_framing(trf, param);
1709 		break;
1710 	default:
1711 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1712 		ret = -EINVAL;
1713 	}
1714 
1715 err_unlock:
1716 	mutex_unlock(&trf->lock);
1717 	return ret;
1718 }
1719 
1720 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1721 			       nfc_digital_cmd_complete_t cb, void *arg,
1722 			       bool mode_detect)
1723 {
1724 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1725 	int ret;
1726 
1727 	mutex_lock(&trf->lock);
1728 
1729 	if ((trf->state != TRF7970A_ST_IDLE) &&
1730 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1731 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1732 			trf->state);
1733 		ret = -EIO;
1734 		goto out_err;
1735 	}
1736 
1737 	if (trf->aborting) {
1738 		dev_dbg(trf->dev, "Abort process complete\n");
1739 		trf->aborting = false;
1740 		ret = -ECANCELED;
1741 		goto out_err;
1742 	}
1743 
1744 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1745 					 GFP_KERNEL);
1746 	if (!trf->rx_skb) {
1747 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1748 		ret = -ENOMEM;
1749 		goto out_err;
1750 	}
1751 
1752 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1753 			     TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1754 			     TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1755 			     TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1756 			     TRF7970A_RX_SPECIAL_SETTINGS_C212);
1757 	if (ret)
1758 		goto out_err;
1759 
1760 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1761 			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1762 	if (ret)
1763 		goto out_err;
1764 
1765 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1766 			     TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1767 	if (ret)
1768 		goto out_err;
1769 
1770 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1771 			     TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1772 	if (ret)
1773 		goto out_err;
1774 
1775 	trf->ddev = ddev;
1776 	trf->cb = cb;
1777 	trf->cb_arg = arg;
1778 	trf->timeout = timeout;
1779 	trf->ignore_timeout = false;
1780 
1781 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1782 	if (ret)
1783 		goto out_err;
1784 
1785 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1786 				   TRF7970A_ST_LISTENING;
1787 
1788 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1789 
1790 out_err:
1791 	mutex_unlock(&trf->lock);
1792 	return ret;
1793 }
1794 
1795 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1796 			      nfc_digital_cmd_complete_t cb, void *arg)
1797 {
1798 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1799 
1800 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1801 		trf->state, timeout);
1802 
1803 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1804 }
1805 
1806 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1807 				 u16 timeout, nfc_digital_cmd_complete_t cb,
1808 				 void *arg)
1809 {
1810 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1811 	int ret;
1812 
1813 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1814 		trf->state, timeout);
1815 
1816 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1817 				       NFC_DIGITAL_RF_TECH_106A);
1818 	if (ret)
1819 		return ret;
1820 
1821 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1822 				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1823 	if (ret)
1824 		return ret;
1825 
1826 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1827 }
1828 
1829 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1830 {
1831 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1832 
1833 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1834 		trf->state, trf->md_rf_tech);
1835 
1836 	*rf_tech = trf->md_rf_tech;
1837 
1838 	return 0;
1839 }
1840 
1841 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1842 {
1843 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1844 
1845 	dev_dbg(trf->dev, "Abort process initiated\n");
1846 
1847 	mutex_lock(&trf->lock);
1848 
1849 	switch (trf->state) {
1850 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1851 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1852 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1853 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1854 		trf->aborting = true;
1855 		break;
1856 	case TRF7970A_ST_LISTENING:
1857 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1858 		trf7970a_send_err_upstream(trf, -ECANCELED);
1859 		dev_dbg(trf->dev, "Abort process complete\n");
1860 		break;
1861 	default:
1862 		break;
1863 	}
1864 
1865 	mutex_unlock(&trf->lock);
1866 }
1867 
1868 static struct nfc_digital_ops trf7970a_nfc_ops = {
1869 	.in_configure_hw	= trf7970a_in_configure_hw,
1870 	.in_send_cmd		= trf7970a_send_cmd,
1871 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1872 	.tg_send_cmd		= trf7970a_send_cmd,
1873 	.tg_listen		= trf7970a_tg_listen,
1874 	.tg_listen_md		= trf7970a_tg_listen_md,
1875 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1876 	.switch_rf		= trf7970a_switch_rf,
1877 	.abort_cmd		= trf7970a_abort_cmd,
1878 };
1879 
1880 static int trf7970a_power_up(struct trf7970a *trf)
1881 {
1882 	int ret;
1883 
1884 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1885 
1886 	if (trf->state != TRF7970A_ST_PWR_OFF)
1887 		return 0;
1888 
1889 	ret = regulator_enable(trf->regulator);
1890 	if (ret) {
1891 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1892 		return ret;
1893 	}
1894 
1895 	usleep_range(5000, 6000);
1896 
1897 	if (trf->en2_gpiod &&
1898 	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1899 		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1900 		usleep_range(1000, 2000);
1901 	}
1902 
1903 	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1904 
1905 	usleep_range(20000, 21000);
1906 
1907 	trf->state = TRF7970A_ST_RF_OFF;
1908 
1909 	return 0;
1910 }
1911 
1912 static int trf7970a_power_down(struct trf7970a *trf)
1913 {
1914 	int ret;
1915 
1916 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1917 
1918 	if (trf->state == TRF7970A_ST_PWR_OFF)
1919 		return 0;
1920 
1921 	if (trf->state != TRF7970A_ST_RF_OFF) {
1922 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1923 			trf->state);
1924 		return -EBUSY;
1925 	}
1926 
1927 	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1928 
1929 	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1930 		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1931 
1932 	ret = regulator_disable(trf->regulator);
1933 	if (ret)
1934 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1935 			ret);
1936 
1937 	trf->state = TRF7970A_ST_PWR_OFF;
1938 
1939 	return ret;
1940 }
1941 
1942 static int trf7970a_startup(struct trf7970a *trf)
1943 {
1944 	int ret;
1945 
1946 	ret = trf7970a_power_up(trf);
1947 	if (ret)
1948 		return ret;
1949 
1950 	pm_runtime_set_active(trf->dev);
1951 	pm_runtime_enable(trf->dev);
1952 	pm_runtime_mark_last_busy(trf->dev);
1953 
1954 	return 0;
1955 }
1956 
1957 static void trf7970a_shutdown(struct trf7970a *trf)
1958 {
1959 	switch (trf->state) {
1960 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1961 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1962 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1963 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1964 	case TRF7970A_ST_LISTENING:
1965 		trf7970a_send_err_upstream(trf, -ECANCELED);
1966 		/* FALLTHROUGH */
1967 	case TRF7970A_ST_IDLE:
1968 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1969 		trf7970a_switch_rf_off(trf);
1970 		break;
1971 	default:
1972 		break;
1973 	}
1974 
1975 	pm_runtime_disable(trf->dev);
1976 	pm_runtime_set_suspended(trf->dev);
1977 
1978 	trf7970a_power_down(trf);
1979 }
1980 
1981 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1982 {
1983 	int autosuspend_delay, ret;
1984 
1985 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1986 	if (ret)
1987 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1988 
1989 	return autosuspend_delay;
1990 }
1991 
1992 static int trf7970a_probe(struct spi_device *spi)
1993 {
1994 	struct device_node *np = spi->dev.of_node;
1995 	struct trf7970a *trf;
1996 	int uvolts, autosuspend_delay, ret;
1997 	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1998 
1999 	if (!np) {
2000 		dev_err(&spi->dev, "No Device Tree entry\n");
2001 		return -EINVAL;
2002 	}
2003 
2004 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2005 	if (!trf)
2006 		return -ENOMEM;
2007 
2008 	trf->state = TRF7970A_ST_PWR_OFF;
2009 	trf->dev = &spi->dev;
2010 	trf->spi = spi;
2011 
2012 	spi->mode = SPI_MODE_1;
2013 	spi->bits_per_word = 8;
2014 
2015 	ret = spi_setup(spi);
2016 	if (ret < 0) {
2017 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2018 		return ret;
2019 	}
2020 
2021 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2022 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2023 
2024 	/* There are two enable pins - only EN must be present in the DT */
2025 	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2026 					     GPIOD_OUT_LOW);
2027 	if (IS_ERR(trf->en_gpiod)) {
2028 		dev_err(trf->dev, "No EN GPIO property\n");
2029 		return PTR_ERR(trf->en_gpiod);
2030 	}
2031 
2032 	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2033 						       GPIOD_OUT_LOW);
2034 	if (!trf->en2_gpiod) {
2035 		dev_info(trf->dev, "No EN2 GPIO property\n");
2036 	} else if (IS_ERR(trf->en2_gpiod)) {
2037 		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2038 			PTR_ERR(trf->en2_gpiod));
2039 		return PTR_ERR(trf->en2_gpiod);
2040 	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2041 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2042 	}
2043 
2044 	of_property_read_u32(np, "clock-frequency", &clk_freq);
2045 	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2046 	    (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2047 		dev_err(trf->dev,
2048 			"clock-frequency (%u Hz) unsupported\n", clk_freq);
2049 		return -EINVAL;
2050 	}
2051 
2052 	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2053 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2054 		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2055 	} else {
2056 		trf->modulator_sys_clk_ctrl = 0;
2057 	}
2058 
2059 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2060 					trf7970a_irq,
2061 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2062 					"trf7970a", trf);
2063 	if (ret) {
2064 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2065 		return ret;
2066 	}
2067 
2068 	mutex_init(&trf->lock);
2069 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2070 
2071 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2072 	if (IS_ERR(trf->regulator)) {
2073 		ret = PTR_ERR(trf->regulator);
2074 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2075 		goto err_destroy_lock;
2076 	}
2077 
2078 	ret = regulator_enable(trf->regulator);
2079 	if (ret) {
2080 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2081 		goto err_destroy_lock;
2082 	}
2083 
2084 	uvolts = regulator_get_voltage(trf->regulator);
2085 	if (uvolts > 4000000)
2086 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2087 
2088 	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2089 	if (IS_ERR(trf->regulator)) {
2090 		ret = PTR_ERR(trf->regulator);
2091 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2092 		goto err_destroy_lock;
2093 	}
2094 
2095 	ret = regulator_enable(trf->regulator);
2096 	if (ret) {
2097 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2098 		goto err_destroy_lock;
2099 	}
2100 
2101 	if (regulator_get_voltage(trf->regulator) == 1800000) {
2102 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2103 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2104 	}
2105 
2106 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2107 						TRF7970A_SUPPORTED_PROTOCOLS,
2108 						NFC_DIGITAL_DRV_CAPS_IN_CRC |
2109 						NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2110 						0);
2111 	if (!trf->ddev) {
2112 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2113 		ret = -ENOMEM;
2114 		goto err_disable_regulator;
2115 	}
2116 
2117 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2118 	nfc_digital_set_drvdata(trf->ddev, trf);
2119 	spi_set_drvdata(spi, trf);
2120 
2121 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2122 
2123 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2124 	pm_runtime_use_autosuspend(trf->dev);
2125 
2126 	ret = trf7970a_startup(trf);
2127 	if (ret)
2128 		goto err_free_ddev;
2129 
2130 	ret = nfc_digital_register_device(trf->ddev);
2131 	if (ret) {
2132 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2133 			ret);
2134 		goto err_shutdown;
2135 	}
2136 
2137 	return 0;
2138 
2139 err_shutdown:
2140 	trf7970a_shutdown(trf);
2141 err_free_ddev:
2142 	nfc_digital_free_device(trf->ddev);
2143 err_disable_regulator:
2144 	regulator_disable(trf->regulator);
2145 err_destroy_lock:
2146 	mutex_destroy(&trf->lock);
2147 	return ret;
2148 }
2149 
2150 static int trf7970a_remove(struct spi_device *spi)
2151 {
2152 	struct trf7970a *trf = spi_get_drvdata(spi);
2153 
2154 	mutex_lock(&trf->lock);
2155 
2156 	trf7970a_shutdown(trf);
2157 
2158 	mutex_unlock(&trf->lock);
2159 
2160 	nfc_digital_unregister_device(trf->ddev);
2161 	nfc_digital_free_device(trf->ddev);
2162 
2163 	regulator_disable(trf->regulator);
2164 
2165 	mutex_destroy(&trf->lock);
2166 
2167 	return 0;
2168 }
2169 
2170 #ifdef CONFIG_PM_SLEEP
2171 static int trf7970a_suspend(struct device *dev)
2172 {
2173 	struct spi_device *spi = to_spi_device(dev);
2174 	struct trf7970a *trf = spi_get_drvdata(spi);
2175 
2176 	dev_dbg(dev, "Suspend\n");
2177 
2178 	mutex_lock(&trf->lock);
2179 
2180 	trf7970a_shutdown(trf);
2181 
2182 	mutex_unlock(&trf->lock);
2183 
2184 	return 0;
2185 }
2186 
2187 static int trf7970a_resume(struct device *dev)
2188 {
2189 	struct spi_device *spi = to_spi_device(dev);
2190 	struct trf7970a *trf = spi_get_drvdata(spi);
2191 	int ret;
2192 
2193 	dev_dbg(dev, "Resume\n");
2194 
2195 	mutex_lock(&trf->lock);
2196 
2197 	ret = trf7970a_startup(trf);
2198 
2199 	mutex_unlock(&trf->lock);
2200 
2201 	return ret;
2202 }
2203 #endif
2204 
2205 #ifdef CONFIG_PM
2206 static int trf7970a_pm_runtime_suspend(struct device *dev)
2207 {
2208 	struct spi_device *spi = to_spi_device(dev);
2209 	struct trf7970a *trf = spi_get_drvdata(spi);
2210 	int ret;
2211 
2212 	dev_dbg(dev, "Runtime suspend\n");
2213 
2214 	mutex_lock(&trf->lock);
2215 
2216 	ret = trf7970a_power_down(trf);
2217 
2218 	mutex_unlock(&trf->lock);
2219 
2220 	return ret;
2221 }
2222 
2223 static int trf7970a_pm_runtime_resume(struct device *dev)
2224 {
2225 	struct spi_device *spi = to_spi_device(dev);
2226 	struct trf7970a *trf = spi_get_drvdata(spi);
2227 	int ret;
2228 
2229 	dev_dbg(dev, "Runtime resume\n");
2230 
2231 	ret = trf7970a_power_up(trf);
2232 	if (!ret)
2233 		pm_runtime_mark_last_busy(dev);
2234 
2235 	return ret;
2236 }
2237 #endif
2238 
2239 static const struct dev_pm_ops trf7970a_pm_ops = {
2240 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2241 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2242 			   trf7970a_pm_runtime_resume, NULL)
2243 };
2244 
2245 static const struct of_device_id trf7970a_of_match[] = {
2246 	{.compatible = "ti,trf7970a",},
2247 	{},
2248 };
2249 
2250 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2251 
2252 static const struct spi_device_id trf7970a_id_table[] = {
2253 	{"trf7970a", 0},
2254 	{}
2255 };
2256 
2257 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2258 
2259 static struct spi_driver trf7970a_spi_driver = {
2260 	.probe		= trf7970a_probe,
2261 	.remove		= trf7970a_remove,
2262 	.id_table	= trf7970a_id_table,
2263 	.driver	= {
2264 		.name		= "trf7970a",
2265 		.of_match_table	= of_match_ptr(trf7970a_of_match),
2266 		.pm		= &trf7970a_pm_ops,
2267 	},
2268 };
2269 
2270 module_spi_driver(trf7970a_spi_driver);
2271 
2272 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2273 MODULE_LICENSE("GPL v2");
2274 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2275