xref: /openbmc/linux/drivers/nfc/trf7970a.c (revision 9aa2cba7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * TI TRF7970a RFID/NFC Transceiver Driver
4  *
5  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
6  *
7  * Author: Erick Macias <emacias@ti.com>
8  * Author: Felipe Balbi <balbi@ti.com>
9  * Author: Mark A. Greer <mgreer@animalcreek.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/netdevice.h>
15 #include <linux/interrupt.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/nfc.h>
18 #include <linux/skbuff.h>
19 #include <linux/delay.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/of.h>
22 #include <linux/spi/spi.h>
23 #include <linux/regulator/consumer.h>
24 
25 #include <net/nfc/nfc.h>
26 #include <net/nfc/digital.h>
27 
28 /* There are 3 ways the host can communicate with the trf7970a:
29  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
30  * SS mode.  The driver only supports the two SPI modes.
31  *
32  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
33  * pins must asserted in that order and with specific delays in between.
34  * The delays used in the driver were provided by TI and have been
35  * confirmed to work with this driver.  There is a bug with the current
36  * version of the trf7970a that requires that EN2 remain low no matter
37  * what.  If it goes high, it will generate an RF field even when in
38  * passive target mode.  TI has indicated that the chip will work okay
39  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
40  * indicates that trf7970a currently being used has the erratum and
41  * that EN2 must be kept low.
42  *
43  * Timeouts are implemented using the delayed workqueue kernel facility.
44  * Timeouts are required so things don't hang when there is no response
45  * from the trf7970a (or tag).  Using this mechanism creates a race with
46  * interrupts, however.  That is, an interrupt and a timeout could occur
47  * closely enough together that one is blocked by the mutex while the other
48  * executes.  When the timeout handler executes first and blocks the
49  * interrupt handler, it will eventually set the state to IDLE so the
50  * interrupt handler will check the state and exit with no harm done.
51  * When the interrupt handler executes first and blocks the timeout handler,
52  * the cancel_delayed_work() call will know that it didn't cancel the
53  * work item (i.e., timeout) and will return zero.  That return code is
54  * used by the timer handler to indicate that it should ignore the timeout
55  * once its unblocked.
56  *
57  * Aborting an active command isn't as simple as it seems because the only
58  * way to abort a command that's already been sent to the tag is so turn
59  * off power to the tag.  If we do that, though, we'd have to go through
60  * the entire anticollision procedure again but the digital layer doesn't
61  * support that.  So, if an abort is received before trf7970a_send_cmd()
62  * has sent the command to the tag, it simply returns -ECANCELED.  If the
63  * command has already been sent to the tag, then the driver continues
64  * normally and recieves the response data (or error) but just before
65  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
66  * upstream instead.  If the command failed, that error will be sent
67  * upstream.
68  *
69  * When recieving data from a tag and the interrupt status register has
70  * only the SRX bit set, it means that all of the data has been received
71  * (once what's in the fifo has been read).  However, depending on timing
72  * an interrupt status with only the SRX bit set may not be recived.  In
73  * those cases, the timeout mechanism is used to wait 20 ms in case more
74  * data arrives.  After 20 ms, it is assumed that all of the data has been
75  * received and the accumulated rx data is sent upstream.  The
76  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
77  * (i.e., it indicates that some data has been received but we're not sure
78  * if there is more coming so a timeout in this state means all data has
79  * been received and there isn't an error).  The delay is 20 ms since delays
80  * of ~16 ms have been observed during testing.
81  *
82  * When transmitting a frame larger than the FIFO size (127 bytes), the
83  * driver will wait 20 ms for the FIFO to drain past the low-watermark
84  * and generate an interrupt.  The low-watermark set to 32 bytes so the
85  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
86  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
87  * to ~14.35 ms so 20 ms is used for the timeout.
88  *
89  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
90  * Having only 4 bits in the FIFO won't normally generate an interrupt so
91  * driver enables the '4_bit_RX' bit of the Special Functions register 1
92  * to cause an interrupt in that case.  Leaving that bit for a read command
93  * messes up the data returned so it is only enabled when the framing is
94  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
95  * Unfortunately, that means that the driver has to peek into tx frames
96  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
97  * the trf7970a_per_cmd_config() routine.
98  *
99  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
100  * frequencies and whether to use low or high data rates in the flags byte
101  * of the frame.  This means that the driver has to peek at all 15693 frames
102  * to determine what speed to set the communication to.  In addition, write
103  * and lock commands use the OPTION flag to indicate that an EOF must be
104  * sent to the tag before it will send its response.  So the driver has to
105  * examine all frames for that reason too.
106  *
107  * It is unclear how long to wait before sending the EOF.  According to the
108  * Note under Table 1-1 in section 1.6 of
109  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
110  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
111  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
112  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
113  * ensure the wait is long enough before sending the EOF.  This seems to work
114  * reliably.
115  */
116 
117 #define TRF7970A_SUPPORTED_PROTOCOLS \
118 		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\
119 		 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
120 		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
121 
122 #define TRF7970A_AUTOSUSPEND_DELAY		30000	/* 30 seconds */
123 #define TRF7970A_13MHZ_CLOCK_FREQUENCY		13560000
124 #define TRF7970A_27MHZ_CLOCK_FREQUENCY		27120000
125 
126 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
127 
128 #define TRF7970A_FIFO_SIZE			127
129 
130 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
131 #define TRF7970A_TX_MAX				(4096 - 1)
132 
133 #define TRF7970A_WAIT_FOR_TX_IRQ		20
134 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
135 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
136 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
137 
138 /* Guard times for various RF technologies (in us) */
139 #define TRF7970A_GUARD_TIME_NFCA		5000
140 #define TRF7970A_GUARD_TIME_NFCB		5000
141 #define TRF7970A_GUARD_TIME_NFCF		20000
142 #define TRF7970A_GUARD_TIME_15693		1000
143 
144 /* Quirks */
145 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
146  * read continuous command for IRQ Status and Collision Position registers.
147  */
148 #define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
149 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
150 
151 /* Direct commands */
152 #define TRF7970A_CMD_IDLE			0x00
153 #define TRF7970A_CMD_SOFT_INIT			0x03
154 #define TRF7970A_CMD_RF_COLLISION		0x04
155 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
156 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
157 #define TRF7970A_CMD_FIFO_RESET			0x0f
158 #define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
159 #define TRF7970A_CMD_TRANSMIT			0x11
160 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
161 #define TRF7970A_CMD_DELAY_TRANSMIT		0x13
162 #define TRF7970A_CMD_EOF			0x14
163 #define TRF7970A_CMD_CLOSE_SLOT			0x15
164 #define TRF7970A_CMD_BLOCK_RX			0x16
165 #define TRF7970A_CMD_ENABLE_RX			0x17
166 #define TRF7970A_CMD_TEST_INT_RF		0x18
167 #define TRF7970A_CMD_TEST_EXT_RF		0x19
168 #define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
169 
170 /* Bits determining whether its a direct command or register R/W,
171  * whether to use a continuous SPI transaction or not, and the actual
172  * direct cmd opcode or register address.
173  */
174 #define TRF7970A_CMD_BIT_CTRL			BIT(7)
175 #define TRF7970A_CMD_BIT_RW			BIT(6)
176 #define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
177 #define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
178 
179 /* Registers addresses */
180 #define TRF7970A_CHIP_STATUS_CTRL		0x00
181 #define TRF7970A_ISO_CTRL			0x01
182 #define TRF7970A_ISO14443B_TX_OPTIONS		0x02
183 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
184 #define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
185 #define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
186 #define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
187 #define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
188 #define TRF7970A_RX_WAIT_TIME			0x08
189 #define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
190 #define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
191 #define TRF7970A_REG_IO_CTRL			0x0b
192 #define TRF7970A_IRQ_STATUS			0x0c
193 #define TRF7970A_COLLISION_IRQ_MASK		0x0d
194 #define TRF7970A_COLLISION_POSITION		0x0e
195 #define TRF7970A_RSSI_OSC_STATUS		0x0f
196 #define TRF7970A_SPECIAL_FCN_REG1		0x10
197 #define TRF7970A_SPECIAL_FCN_REG2		0x11
198 #define TRF7970A_RAM1				0x12
199 #define TRF7970A_RAM2				0x13
200 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
201 #define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
202 #define TRF7970A_NFCID1				0x17
203 #define TRF7970A_NFC_TARGET_LEVEL		0x18
204 #define TRF79070A_NFC_TARGET_PROTOCOL		0x19
205 #define TRF7970A_TEST_REGISTER1			0x1a
206 #define TRF7970A_TEST_REGISTER2			0x1b
207 #define TRF7970A_FIFO_STATUS			0x1c
208 #define TRF7970A_TX_LENGTH_BYTE1		0x1d
209 #define TRF7970A_TX_LENGTH_BYTE2		0x1e
210 #define TRF7970A_FIFO_IO_REGISTER		0x1f
211 
212 /* Chip Status Control Register Bits */
213 #define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
214 #define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
215 #define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
216 #define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
217 #define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
218 #define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
219 #define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
220 #define TRF7970A_CHIP_STATUS_STBY		BIT(7)
221 
222 /* ISO Control Register Bits */
223 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
224 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
225 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
227 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
228 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
229 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
231 #define TRF7970A_ISO_CTRL_14443A_106		0x08
232 #define TRF7970A_ISO_CTRL_14443A_212		0x09
233 #define TRF7970A_ISO_CTRL_14443A_424		0x0a
234 #define TRF7970A_ISO_CTRL_14443A_848		0x0b
235 #define TRF7970A_ISO_CTRL_14443B_106		0x0c
236 #define TRF7970A_ISO_CTRL_14443B_212		0x0d
237 #define TRF7970A_ISO_CTRL_14443B_424		0x0e
238 #define TRF7970A_ISO_CTRL_14443B_848		0x0f
239 #define TRF7970A_ISO_CTRL_FELICA_212		0x1a
240 #define TRF7970A_ISO_CTRL_FELICA_424		0x1b
241 #define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
242 #define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
243 #define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
244 #define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
245 #define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
246 #define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
247 #define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
248 #define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
249 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
250 #define TRF7970A_ISO_CTRL_RFID			BIT(5)
251 #define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
252 #define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
253 
254 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
255 
256 /* Modulator and SYS_CLK Control Register Bits */
257 #define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
258 #define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
259 #define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
260 #define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
261 #define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
262 #define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
263 #define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
264 #define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
265 #define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
266 #define TRF7970A_MODULATOR_EN_ANA		BIT(3)
267 #define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
268 #define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
269 #define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
270 #define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
271 #define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
272 #define TRF7970A_MODULATOR_EN_OOK		BIT(6)
273 #define TRF7970A_MODULATOR_27MHZ		BIT(7)
274 
275 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
276 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
277 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
278 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
279 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
281 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
282 #define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
285 
286 #define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
287 #define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
288 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
289 #define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
290 
291 /* IRQ Status Register Bits */
292 #define TRF7970A_IRQ_STATUS_NORESP		BIT(0)	/* ISO15693 only */
293 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
294 #define TRF7970A_IRQ_STATUS_COL			BIT(1)
295 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
296 #define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
297 #define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
298 #define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
299 #define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
300 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
301 #define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
302 #define TRF7970A_IRQ_STATUS_SRX			BIT(6)
303 #define TRF7970A_IRQ_STATUS_TX			BIT(7)
304 
305 #define TRF7970A_IRQ_STATUS_ERROR				\
306 		(TRF7970A_IRQ_STATUS_COL |			\
307 		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
308 		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
309 		 TRF7970A_IRQ_STATUS_CRC_ERROR)
310 
311 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
312 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
313 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
314 
315 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
316 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
317 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
318 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
319 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
320 #define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
321 
322 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
323 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
324 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
325 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
326 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
330 
331 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
332 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
333 
334 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
335 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
336 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
337 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
338 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
339 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
340 
341 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
342 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
343 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
344 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
345 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
346 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
347 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
349 
350 #define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
351 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
352 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
353 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
354 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
355 
356 #define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
357 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
358 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
359 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
360 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
361 
362 #define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
363 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
364 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
365 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
366 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
367 
368 #define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
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_424)
373 
374 #define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
375 
376 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
377 #define NFC_T2T_CMD_READ			0x30
378 
379 /* ISO 15693 commands codes */
380 #define ISO15693_CMD_INVENTORY			0x01
381 #define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
382 #define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
383 #define ISO15693_CMD_LOCK_BLOCK			0x22
384 #define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
385 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
386 #define ISO15693_CMD_SELECT			0x25
387 #define ISO15693_CMD_RESET_TO_READY		0x26
388 #define ISO15693_CMD_WRITE_AFI			0x27
389 #define ISO15693_CMD_LOCK_AFI			0x28
390 #define ISO15693_CMD_WRITE_DSFID		0x29
391 #define ISO15693_CMD_LOCK_DSFID			0x2a
392 #define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
393 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
394 
395 /* ISO 15693 request and response flags */
396 #define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
397 #define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
398 #define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
399 #define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
400 #define ISO15693_REQ_FLAG_SELECT		BIT(4)
401 #define ISO15693_REQ_FLAG_AFI			BIT(4)
402 #define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
403 #define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
404 #define ISO15693_REQ_FLAG_OPTION		BIT(6)
405 
406 #define ISO15693_REQ_FLAG_SPEED_MASK \
407 		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
408 
409 enum trf7970a_state {
410 	TRF7970A_ST_PWR_OFF,
411 	TRF7970A_ST_RF_OFF,
412 	TRF7970A_ST_IDLE,
413 	TRF7970A_ST_IDLE_RX_BLOCKED,
414 	TRF7970A_ST_WAIT_FOR_TX_FIFO,
415 	TRF7970A_ST_WAIT_FOR_RX_DATA,
416 	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
417 	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
418 	TRF7970A_ST_LISTENING,
419 	TRF7970A_ST_LISTENING_MD,
420 	TRF7970A_ST_MAX
421 };
422 
423 struct trf7970a {
424 	enum trf7970a_state		state;
425 	struct device			*dev;
426 	struct spi_device		*spi;
427 	struct regulator		*regulator;
428 	struct nfc_digital_dev		*ddev;
429 	u32				quirks;
430 	bool				is_initiator;
431 	bool				aborting;
432 	struct sk_buff			*tx_skb;
433 	struct sk_buff			*rx_skb;
434 	nfc_digital_cmd_complete_t	cb;
435 	void				*cb_arg;
436 	u8				chip_status_ctrl;
437 	u8				iso_ctrl;
438 	u8				iso_ctrl_tech;
439 	u8				modulator_sys_clk_ctrl;
440 	u8				special_fcn_reg1;
441 	u8				io_ctrl;
442 	unsigned int			guard_time;
443 	int				technology;
444 	int				framing;
445 	u8				md_rf_tech;
446 	u8				tx_cmd;
447 	bool				issue_eof;
448 	struct gpio_desc		*en_gpiod;
449 	struct gpio_desc		*en2_gpiod;
450 	struct mutex			lock;
451 	unsigned int			timeout;
452 	bool				ignore_timeout;
453 	struct delayed_work		timeout_work;
454 };
455 
456 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
457 {
458 	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
459 	int ret;
460 
461 	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
462 
463 	ret = spi_write(trf->spi, &cmd, 1);
464 	if (ret)
465 		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
466 			ret);
467 	return ret;
468 }
469 
470 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
471 {
472 	u8 addr = TRF7970A_CMD_BIT_RW | reg;
473 	int ret;
474 
475 	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
476 	if (ret)
477 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
478 			ret);
479 
480 	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
481 
482 	return ret;
483 }
484 
485 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
486 			      size_t len)
487 {
488 	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
489 	struct spi_transfer t[2];
490 	struct spi_message m;
491 	int ret;
492 
493 	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
494 
495 	spi_message_init(&m);
496 
497 	memset(&t, 0, sizeof(t));
498 
499 	t[0].tx_buf = &addr;
500 	t[0].len = sizeof(addr);
501 	spi_message_add_tail(&t[0], &m);
502 
503 	t[1].rx_buf = buf;
504 	t[1].len = len;
505 	spi_message_add_tail(&t[1], &m);
506 
507 	ret = spi_sync(trf->spi, &m);
508 	if (ret)
509 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
510 			ret);
511 	return ret;
512 }
513 
514 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
515 {
516 	u8 buf[2] = { reg, val };
517 	int ret;
518 
519 	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
520 
521 	ret = spi_write(trf->spi, buf, 2);
522 	if (ret)
523 		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
524 			buf[0], buf[1], ret);
525 
526 	return ret;
527 }
528 
529 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
530 {
531 	int ret;
532 	u8 buf[2];
533 	u8 addr;
534 
535 	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
536 
537 	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
538 		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
539 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
540 	} else {
541 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
542 	}
543 
544 	if (ret)
545 		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
546 			__func__, ret);
547 	else
548 		*status = buf[0];
549 
550 	return ret;
551 }
552 
553 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
554 {
555 	int ret;
556 	u8 buf[2];
557 	u8 addr;
558 
559 	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
560 	       TRF7970A_CMD_BIT_CONTINUOUS;
561 
562 	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
563 	if (ret)
564 		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
565 			__func__, ret);
566 	else
567 		*target_proto = buf[0];
568 
569 	return ret;
570 }
571 
572 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
573 {
574 	int ret;
575 	u8 target_proto, tech;
576 
577 	ret = trf7970a_read_target_proto(trf, &target_proto);
578 	if (ret)
579 		return ret;
580 
581 	switch (target_proto) {
582 	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
583 		tech = NFC_DIGITAL_RF_TECH_106A;
584 		break;
585 	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
586 		tech = NFC_DIGITAL_RF_TECH_106B;
587 		break;
588 	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
589 		tech = NFC_DIGITAL_RF_TECH_212F;
590 		break;
591 	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
592 		tech = NFC_DIGITAL_RF_TECH_424F;
593 		break;
594 	default:
595 		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
596 			__func__, target_proto);
597 		return -EIO;
598 	}
599 
600 	*rf_tech = tech;
601 
602 	return ret;
603 }
604 
605 static void trf7970a_send_upstream(struct trf7970a *trf)
606 {
607 	dev_kfree_skb_any(trf->tx_skb);
608 	trf->tx_skb = NULL;
609 
610 	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
611 		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
612 				     16, 1, trf->rx_skb->data, trf->rx_skb->len,
613 				     false);
614 
615 	trf->state = TRF7970A_ST_IDLE;
616 
617 	if (trf->aborting) {
618 		dev_dbg(trf->dev, "Abort process complete\n");
619 
620 		if (!IS_ERR(trf->rx_skb)) {
621 			kfree_skb(trf->rx_skb);
622 			trf->rx_skb = ERR_PTR(-ECANCELED);
623 		}
624 
625 		trf->aborting = false;
626 	}
627 
628 	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
629 
630 	trf->rx_skb = NULL;
631 }
632 
633 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
634 {
635 	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
636 
637 	cancel_delayed_work(&trf->timeout_work);
638 
639 	kfree_skb(trf->rx_skb);
640 	trf->rx_skb = ERR_PTR(errno);
641 
642 	trf7970a_send_upstream(trf);
643 }
644 
645 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
646 			     unsigned int len, const u8 *prefix,
647 			     unsigned int prefix_len)
648 {
649 	struct spi_transfer t[2];
650 	struct spi_message m;
651 	unsigned int timeout;
652 	int ret;
653 
654 	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
655 			     16, 1, skb->data, len, false);
656 
657 	spi_message_init(&m);
658 
659 	memset(&t, 0, sizeof(t));
660 
661 	t[0].tx_buf = prefix;
662 	t[0].len = prefix_len;
663 	spi_message_add_tail(&t[0], &m);
664 
665 	t[1].tx_buf = skb->data;
666 	t[1].len = len;
667 	spi_message_add_tail(&t[1], &m);
668 
669 	ret = spi_sync(trf->spi, &m);
670 	if (ret) {
671 		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
672 			ret);
673 		return ret;
674 	}
675 
676 	skb_pull(skb, len);
677 
678 	if (skb->len > 0) {
679 		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
680 		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
681 	} else {
682 		if (trf->issue_eof) {
683 			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
684 			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
685 		} else {
686 			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
687 
688 			if (!trf->timeout)
689 				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
690 			else
691 				timeout = trf->timeout;
692 		}
693 	}
694 
695 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
696 		trf->state);
697 
698 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
699 
700 	return 0;
701 }
702 
703 static void trf7970a_fill_fifo(struct trf7970a *trf)
704 {
705 	struct sk_buff *skb = trf->tx_skb;
706 	unsigned int len;
707 	int ret;
708 	u8 fifo_bytes;
709 	u8 prefix;
710 
711 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
712 	if (ret) {
713 		trf7970a_send_err_upstream(trf, ret);
714 		return;
715 	}
716 
717 	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
718 
719 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
720 
721 	/* Calculate how much more data can be written to the fifo */
722 	len = TRF7970A_FIFO_SIZE - fifo_bytes;
723 	if (!len) {
724 		schedule_delayed_work(&trf->timeout_work,
725 			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
726 		return;
727 	}
728 
729 	len = min(skb->len, len);
730 
731 	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
732 
733 	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
734 	if (ret)
735 		trf7970a_send_err_upstream(trf, ret);
736 }
737 
738 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
739 {
740 	struct sk_buff *skb = trf->rx_skb;
741 	int ret;
742 	u8 fifo_bytes;
743 
744 	if (status & TRF7970A_IRQ_STATUS_ERROR) {
745 		trf7970a_send_err_upstream(trf, -EIO);
746 		return;
747 	}
748 
749 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
750 	if (ret) {
751 		trf7970a_send_err_upstream(trf, ret);
752 		return;
753 	}
754 
755 	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
756 
757 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
758 
759 	if (!fifo_bytes)
760 		goto no_rx_data;
761 
762 	if (fifo_bytes > skb_tailroom(skb)) {
763 		skb = skb_copy_expand(skb, skb_headroom(skb),
764 				      max_t(int, fifo_bytes,
765 					    TRF7970A_RX_SKB_ALLOC_SIZE),
766 				      GFP_KERNEL);
767 		if (!skb) {
768 			trf7970a_send_err_upstream(trf, -ENOMEM);
769 			return;
770 		}
771 
772 		kfree_skb(trf->rx_skb);
773 		trf->rx_skb = skb;
774 	}
775 
776 	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
777 				 skb_put(skb, fifo_bytes), fifo_bytes);
778 	if (ret) {
779 		trf7970a_send_err_upstream(trf, ret);
780 		return;
781 	}
782 
783 	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
784 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
785 	    (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
786 		skb->data[0] >>= 4;
787 		status = TRF7970A_IRQ_STATUS_SRX;
788 	} else {
789 		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
790 
791 		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
792 		if (ret) {
793 			trf7970a_send_err_upstream(trf, ret);
794 			return;
795 		}
796 
797 		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
798 
799 		/* If there are bytes in the FIFO, set status to '0' so
800 		 * the if stmt below doesn't fire and the driver will wait
801 		 * for the trf7970a to generate another RX interrupt.
802 		 */
803 		if (fifo_bytes)
804 			status = 0;
805 	}
806 
807 no_rx_data:
808 	if (status == TRF7970A_IRQ_STATUS_SRX) {	/* Receive complete */
809 		trf7970a_send_upstream(trf);
810 		return;
811 	}
812 
813 	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
814 		TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
815 
816 	schedule_delayed_work(&trf->timeout_work,
817 			   msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
818 }
819 
820 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
821 {
822 	struct trf7970a *trf = dev_id;
823 	int ret;
824 	u8 status, fifo_bytes, iso_ctrl;
825 
826 	mutex_lock(&trf->lock);
827 
828 	if (trf->state == TRF7970A_ST_RF_OFF) {
829 		mutex_unlock(&trf->lock);
830 		return IRQ_NONE;
831 	}
832 
833 	ret = trf7970a_read_irqstatus(trf, &status);
834 	if (ret) {
835 		mutex_unlock(&trf->lock);
836 		return IRQ_NONE;
837 	}
838 
839 	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
840 		status);
841 
842 	if (!status) {
843 		mutex_unlock(&trf->lock);
844 		return IRQ_NONE;
845 	}
846 
847 	switch (trf->state) {
848 	case TRF7970A_ST_IDLE:
849 	case TRF7970A_ST_IDLE_RX_BLOCKED:
850 		/* If initiator and getting interrupts caused by RF noise,
851 		 * turn off the receiver to avoid unnecessary interrupts.
852 		 * It will be turned back on in trf7970a_send_cmd() when
853 		 * the next command is issued.
854 		 */
855 		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
856 			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
857 			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
858 		}
859 
860 		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
861 		break;
862 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
863 		if (status & TRF7970A_IRQ_STATUS_TX) {
864 			trf->ignore_timeout =
865 			    !cancel_delayed_work(&trf->timeout_work);
866 			trf7970a_fill_fifo(trf);
867 		} else {
868 			trf7970a_send_err_upstream(trf, -EIO);
869 		}
870 		break;
871 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
872 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
873 		if (status & TRF7970A_IRQ_STATUS_SRX) {
874 			trf->ignore_timeout =
875 			    !cancel_delayed_work(&trf->timeout_work);
876 			trf7970a_drain_fifo(trf, status);
877 		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
878 			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
879 					    &fifo_bytes);
880 
881 			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
882 
883 			if (ret)
884 				trf7970a_send_err_upstream(trf, ret);
885 			else if (!fifo_bytes)
886 				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
887 		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
888 			   (!trf->is_initiator &&
889 			    (status == (TRF7970A_IRQ_STATUS_TX |
890 					TRF7970A_IRQ_STATUS_NFC_RF)))) {
891 			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
892 
893 			if (!trf->timeout) {
894 				trf->ignore_timeout =
895 				    !cancel_delayed_work(&trf->timeout_work);
896 				trf->rx_skb = ERR_PTR(0);
897 				trf7970a_send_upstream(trf);
898 				break;
899 			}
900 
901 			if (trf->is_initiator)
902 				break;
903 
904 			iso_ctrl = trf->iso_ctrl;
905 
906 			switch (trf->framing) {
907 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
908 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
909 				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
910 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
911 				break;
912 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
913 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
914 				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
915 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
916 				break;
917 			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
918 				ret = trf7970a_write(trf,
919 					 TRF7970A_SPECIAL_FCN_REG1,
920 					 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
921 				if (ret)
922 					goto err_unlock_exit;
923 
924 				trf->special_fcn_reg1 =
925 				    TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
926 				break;
927 			default:
928 				break;
929 			}
930 
931 			if (iso_ctrl != trf->iso_ctrl) {
932 				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
933 						     iso_ctrl);
934 				if (ret)
935 					goto err_unlock_exit;
936 
937 				trf->iso_ctrl = iso_ctrl;
938 			}
939 		} else {
940 			trf7970a_send_err_upstream(trf, -EIO);
941 		}
942 		break;
943 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
944 		if (status != TRF7970A_IRQ_STATUS_TX)
945 			trf7970a_send_err_upstream(trf, -EIO);
946 		break;
947 	case TRF7970A_ST_LISTENING:
948 		if (status & TRF7970A_IRQ_STATUS_SRX) {
949 			trf->ignore_timeout =
950 			    !cancel_delayed_work(&trf->timeout_work);
951 			trf7970a_drain_fifo(trf, status);
952 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
953 			trf7970a_send_err_upstream(trf, -EIO);
954 		}
955 		break;
956 	case TRF7970A_ST_LISTENING_MD:
957 		if (status & TRF7970A_IRQ_STATUS_SRX) {
958 			trf->ignore_timeout =
959 			    !cancel_delayed_work(&trf->timeout_work);
960 
961 			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
962 			if (ret) {
963 				trf7970a_send_err_upstream(trf, ret);
964 			} else {
965 				trf->state = TRF7970A_ST_LISTENING;
966 				trf7970a_drain_fifo(trf, status);
967 			}
968 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
969 			trf7970a_send_err_upstream(trf, -EIO);
970 		}
971 		break;
972 	default:
973 		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
974 			__func__, trf->state);
975 	}
976 
977 err_unlock_exit:
978 	mutex_unlock(&trf->lock);
979 	return IRQ_HANDLED;
980 }
981 
982 static void trf7970a_issue_eof(struct trf7970a *trf)
983 {
984 	int ret;
985 
986 	dev_dbg(trf->dev, "Issuing EOF\n");
987 
988 	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
989 	if (ret)
990 		trf7970a_send_err_upstream(trf, ret);
991 
992 	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
993 	if (ret)
994 		trf7970a_send_err_upstream(trf, ret);
995 
996 	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
997 
998 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
999 		trf->timeout, trf->state);
1000 
1001 	schedule_delayed_work(&trf->timeout_work,
1002 			      msecs_to_jiffies(trf->timeout));
1003 }
1004 
1005 static void trf7970a_timeout_work_handler(struct work_struct *work)
1006 {
1007 	struct trf7970a *trf = container_of(work, struct trf7970a,
1008 					    timeout_work.work);
1009 
1010 	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1011 		trf->state, trf->ignore_timeout);
1012 
1013 	mutex_lock(&trf->lock);
1014 
1015 	if (trf->ignore_timeout)
1016 		trf->ignore_timeout = false;
1017 	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1018 		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1019 	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1020 		trf7970a_issue_eof(trf);
1021 	else
1022 		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1023 
1024 	mutex_unlock(&trf->lock);
1025 }
1026 
1027 static int trf7970a_init(struct trf7970a *trf)
1028 {
1029 	int ret;
1030 
1031 	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1032 
1033 	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1034 	if (ret)
1035 		goto err_out;
1036 
1037 	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1038 	if (ret)
1039 		goto err_out;
1040 
1041 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1042 			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1043 	if (ret)
1044 		goto err_out;
1045 
1046 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1047 	if (ret)
1048 		goto err_out;
1049 
1050 	usleep_range(1000, 2000);
1051 
1052 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1053 
1054 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1055 			     trf->modulator_sys_clk_ctrl);
1056 	if (ret)
1057 		goto err_out;
1058 
1059 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1060 			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1061 			     TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1062 	if (ret)
1063 		goto err_out;
1064 
1065 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1066 	if (ret)
1067 		goto err_out;
1068 
1069 	trf->special_fcn_reg1 = 0;
1070 
1071 	trf->iso_ctrl = 0xff;
1072 	return 0;
1073 
1074 err_out:
1075 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1076 	return ret;
1077 }
1078 
1079 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1080 {
1081 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1082 	    (trf->state == TRF7970A_ST_RF_OFF))
1083 		return;
1084 
1085 	dev_dbg(trf->dev, "Switching rf off\n");
1086 
1087 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1088 
1089 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1090 
1091 	trf->aborting = false;
1092 	trf->state = TRF7970A_ST_RF_OFF;
1093 
1094 	pm_runtime_mark_last_busy(trf->dev);
1095 	pm_runtime_put_autosuspend(trf->dev);
1096 }
1097 
1098 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1099 {
1100 	int ret;
1101 
1102 	dev_dbg(trf->dev, "Switching rf on\n");
1103 
1104 	pm_runtime_get_sync(trf->dev);
1105 
1106 	if (trf->state != TRF7970A_ST_RF_OFF) {	/* Power on, RF off */
1107 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1108 			trf->state);
1109 		return -EINVAL;
1110 	}
1111 
1112 	ret = trf7970a_init(trf);
1113 	if (ret) {
1114 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1115 		return ret;
1116 	}
1117 
1118 	trf->state = TRF7970A_ST_IDLE;
1119 
1120 	return 0;
1121 }
1122 
1123 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1124 {
1125 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1126 	int ret = 0;
1127 
1128 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1129 
1130 	mutex_lock(&trf->lock);
1131 
1132 	if (on) {
1133 		switch (trf->state) {
1134 		case TRF7970A_ST_PWR_OFF:
1135 		case TRF7970A_ST_RF_OFF:
1136 			ret = trf7970a_switch_rf_on(trf);
1137 			break;
1138 		case TRF7970A_ST_IDLE:
1139 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1140 			break;
1141 		default:
1142 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1143 				__func__, trf->state, on);
1144 			trf7970a_switch_rf_off(trf);
1145 			ret = -EINVAL;
1146 		}
1147 	} else {
1148 		switch (trf->state) {
1149 		case TRF7970A_ST_PWR_OFF:
1150 		case TRF7970A_ST_RF_OFF:
1151 			break;
1152 		default:
1153 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1154 				__func__, trf->state, on);
1155 			ret = -EINVAL;
1156 			fallthrough;
1157 		case TRF7970A_ST_IDLE:
1158 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1159 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1160 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1161 			trf7970a_switch_rf_off(trf);
1162 		}
1163 	}
1164 
1165 	mutex_unlock(&trf->lock);
1166 	return ret;
1167 }
1168 
1169 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1170 {
1171 	int ret = 0;
1172 
1173 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1174 
1175 	switch (tech) {
1176 	case NFC_DIGITAL_RF_TECH_106A:
1177 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1178 		trf->modulator_sys_clk_ctrl =
1179 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1180 		    TRF7970A_MODULATOR_DEPTH_OOK;
1181 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1182 		break;
1183 	case NFC_DIGITAL_RF_TECH_106B:
1184 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1185 		trf->modulator_sys_clk_ctrl =
1186 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1187 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1188 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1189 		break;
1190 	case NFC_DIGITAL_RF_TECH_212F:
1191 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1192 		trf->modulator_sys_clk_ctrl =
1193 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1194 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1195 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1196 		break;
1197 	case NFC_DIGITAL_RF_TECH_424F:
1198 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
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_NFCF;
1203 		break;
1204 	case NFC_DIGITAL_RF_TECH_ISO15693:
1205 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1206 		trf->modulator_sys_clk_ctrl =
1207 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1208 		    TRF7970A_MODULATOR_DEPTH_OOK;
1209 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1210 		break;
1211 	default:
1212 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1213 		return -EINVAL;
1214 	}
1215 
1216 	trf->technology = tech;
1217 
1218 	/* If in initiator mode and not changing the RF tech due to a
1219 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1220 	 * trf7970a_init()), clear the NFC Target Detection Level register
1221 	 * due to erratum.
1222 	 */
1223 	if (trf->iso_ctrl == 0xff)
1224 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1225 
1226 	return ret;
1227 }
1228 
1229 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1230 {
1231 	int ret;
1232 	u8 rssi;
1233 
1234 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1235 			     trf->chip_status_ctrl |
1236 			     TRF7970A_CHIP_STATUS_REC_ON);
1237 	if (ret)
1238 		return ret;
1239 
1240 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1241 	if (ret)
1242 		return ret;
1243 
1244 	usleep_range(50, 60);
1245 
1246 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1247 	if (ret)
1248 		return ret;
1249 
1250 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1251 			     trf->chip_status_ctrl);
1252 	if (ret)
1253 		return ret;
1254 
1255 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1256 		*is_rf_field = true;
1257 	else
1258 		*is_rf_field = false;
1259 
1260 	return 0;
1261 }
1262 
1263 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1264 {
1265 	u8 iso_ctrl = trf->iso_ctrl_tech;
1266 	bool is_rf_field = false;
1267 	int ret;
1268 
1269 	dev_dbg(trf->dev, "framing: %d\n", framing);
1270 
1271 	switch (framing) {
1272 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1273 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1274 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1275 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1276 		break;
1277 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1278 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1279 	case NFC_DIGITAL_FRAMING_NFCB:
1280 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1281 	case NFC_DIGITAL_FRAMING_NFCF:
1282 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1283 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1284 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1285 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1286 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1287 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1288 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1289 		break;
1290 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1291 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1292 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1293 		break;
1294 	default:
1295 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1296 		return -EINVAL;
1297 	}
1298 
1299 	trf->framing = framing;
1300 
1301 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1302 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1303 		if (ret)
1304 			return ret;
1305 
1306 		if (is_rf_field)
1307 			return -EBUSY;
1308 	}
1309 
1310 	if (iso_ctrl != trf->iso_ctrl) {
1311 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1312 		if (ret)
1313 			return ret;
1314 
1315 		trf->iso_ctrl = iso_ctrl;
1316 
1317 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1318 				     trf->modulator_sys_clk_ctrl);
1319 		if (ret)
1320 			return ret;
1321 	}
1322 
1323 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1324 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1325 				     trf->chip_status_ctrl |
1326 				     TRF7970A_CHIP_STATUS_RF_ON);
1327 		if (ret)
1328 			return ret;
1329 
1330 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1331 
1332 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1333 	}
1334 
1335 	return 0;
1336 }
1337 
1338 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1339 				    int param)
1340 {
1341 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1342 	int ret;
1343 
1344 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1345 
1346 	mutex_lock(&trf->lock);
1347 
1348 	trf->is_initiator = true;
1349 
1350 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1351 	    (trf->state == TRF7970A_ST_RF_OFF)) {
1352 		ret = trf7970a_switch_rf_on(trf);
1353 		if (ret)
1354 			goto err_unlock;
1355 	}
1356 
1357 	switch (type) {
1358 	case NFC_DIGITAL_CONFIG_RF_TECH:
1359 		ret = trf7970a_in_config_rf_tech(trf, param);
1360 		break;
1361 	case NFC_DIGITAL_CONFIG_FRAMING:
1362 		ret = trf7970a_in_config_framing(trf, param);
1363 		break;
1364 	default:
1365 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1366 		ret = -EINVAL;
1367 	}
1368 
1369 err_unlock:
1370 	mutex_unlock(&trf->lock);
1371 	return ret;
1372 }
1373 
1374 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1375 {
1376 	switch (cmd) {
1377 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1378 	case ISO15693_CMD_LOCK_BLOCK:
1379 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1380 	case ISO15693_CMD_WRITE_AFI:
1381 	case ISO15693_CMD_LOCK_AFI:
1382 	case ISO15693_CMD_WRITE_DSFID:
1383 	case ISO15693_CMD_LOCK_DSFID:
1384 		return 1;
1385 	default:
1386 		return 0;
1387 	}
1388 }
1389 
1390 static int trf7970a_per_cmd_config(struct trf7970a *trf,
1391 				   const struct sk_buff *skb)
1392 {
1393 	const u8 *req = skb->data;
1394 	u8 special_fcn_reg1, iso_ctrl;
1395 	int ret;
1396 
1397 	trf->issue_eof = false;
1398 
1399 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1400 	 * special functions register 1 is cleared; otherwise, its a write or
1401 	 * sector select command and '4_bit_RX' must be set.
1402 	 *
1403 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1404 	 * what speed to use.  Also, remember if the OPTION flag is set on
1405 	 * a Type 5 write or lock command so the driver will know that it
1406 	 * has to send an EOF in order to get a response.
1407 	 */
1408 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1409 	    (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1410 		if (req[0] == NFC_T2T_CMD_READ)
1411 			special_fcn_reg1 = 0;
1412 		else
1413 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1414 
1415 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1416 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1417 					     special_fcn_reg1);
1418 			if (ret)
1419 				return ret;
1420 
1421 			trf->special_fcn_reg1 = special_fcn_reg1;
1422 		}
1423 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1424 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1425 
1426 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1427 		case 0x00:
1428 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1429 			break;
1430 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1431 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1432 			break;
1433 		case ISO15693_REQ_FLAG_DATA_RATE:
1434 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1435 			break;
1436 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1437 		      ISO15693_REQ_FLAG_DATA_RATE):
1438 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1439 			break;
1440 		}
1441 
1442 		if (iso_ctrl != trf->iso_ctrl) {
1443 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1444 			if (ret)
1445 				return ret;
1446 
1447 			trf->iso_ctrl = iso_ctrl;
1448 		}
1449 
1450 		if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1451 		    trf7970a_is_iso15693_write_or_lock(req[1]) &&
1452 		    (req[0] & ISO15693_REQ_FLAG_OPTION))
1453 			trf->issue_eof = true;
1454 	}
1455 
1456 	return 0;
1457 }
1458 
1459 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1460 			     struct sk_buff *skb, u16 timeout,
1461 			     nfc_digital_cmd_complete_t cb, void *arg)
1462 {
1463 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1464 	u8 prefix[5];
1465 	unsigned int len;
1466 	int ret;
1467 	u8 status;
1468 
1469 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1470 		trf->state, timeout, skb->len);
1471 
1472 	if (skb->len > TRF7970A_TX_MAX)
1473 		return -EINVAL;
1474 
1475 	mutex_lock(&trf->lock);
1476 
1477 	if ((trf->state != TRF7970A_ST_IDLE) &&
1478 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1479 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1480 			trf->state);
1481 		ret = -EIO;
1482 		goto out_err;
1483 	}
1484 
1485 	if (trf->aborting) {
1486 		dev_dbg(trf->dev, "Abort process complete\n");
1487 		trf->aborting = false;
1488 		ret = -ECANCELED;
1489 		goto out_err;
1490 	}
1491 
1492 	if (timeout) {
1493 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1494 						 GFP_KERNEL);
1495 		if (!trf->rx_skb) {
1496 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1497 			ret = -ENOMEM;
1498 			goto out_err;
1499 		}
1500 	}
1501 
1502 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1503 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1504 		if (ret)
1505 			goto out_err;
1506 
1507 		trf->state = TRF7970A_ST_IDLE;
1508 	}
1509 
1510 	if (trf->is_initiator) {
1511 		ret = trf7970a_per_cmd_config(trf, skb);
1512 		if (ret)
1513 			goto out_err;
1514 	}
1515 
1516 	trf->ddev = ddev;
1517 	trf->tx_skb = skb;
1518 	trf->cb = cb;
1519 	trf->cb_arg = arg;
1520 	trf->timeout = timeout;
1521 	trf->ignore_timeout = false;
1522 
1523 	len = skb->len;
1524 
1525 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1526 	 * on what the current framing is, the address of the TX length byte 1
1527 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1528 	 * That totals 5 bytes.
1529 	 */
1530 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1531 	    TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1532 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1533 	    TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1534 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1535 
1536 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1537 		prefix[3] = 0x00;
1538 		prefix[4] = 0x0f;	/* 7 bits */
1539 	} else {
1540 		prefix[3] = (len & 0xf00) >> 4;
1541 		prefix[3] |= ((len & 0xf0) >> 4);
1542 		prefix[4] = ((len & 0x0f) << 4);
1543 	}
1544 
1545 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1546 
1547 	/* Clear possible spurious interrupt */
1548 	ret = trf7970a_read_irqstatus(trf, &status);
1549 	if (ret)
1550 		goto out_err;
1551 
1552 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1553 	if (ret) {
1554 		kfree_skb(trf->rx_skb);
1555 		trf->rx_skb = NULL;
1556 	}
1557 
1558 out_err:
1559 	mutex_unlock(&trf->lock);
1560 	return ret;
1561 }
1562 
1563 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1564 {
1565 	int ret = 0;
1566 
1567 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1568 
1569 	switch (tech) {
1570 	case NFC_DIGITAL_RF_TECH_106A:
1571 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1572 		    TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1573 		trf->modulator_sys_clk_ctrl =
1574 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1575 		    TRF7970A_MODULATOR_DEPTH_OOK;
1576 		break;
1577 	case NFC_DIGITAL_RF_TECH_212F:
1578 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1579 		    TRF7970A_ISO_CTRL_NFC_NFCF_212;
1580 		trf->modulator_sys_clk_ctrl =
1581 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1582 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1583 		break;
1584 	case NFC_DIGITAL_RF_TECH_424F:
1585 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1586 		    TRF7970A_ISO_CTRL_NFC_NFCF_424;
1587 		trf->modulator_sys_clk_ctrl =
1588 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1589 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1590 		break;
1591 	default:
1592 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1593 		return -EINVAL;
1594 	}
1595 
1596 	trf->technology = tech;
1597 
1598 	/* Normally we write the ISO_CTRL register in
1599 	 * trf7970a_tg_config_framing() because the framing can change
1600 	 * the value written.  However, when sending a PSL RES,
1601 	 * digital_tg_send_psl_res_complete() doesn't call
1602 	 * trf7970a_tg_config_framing() so we must write the register
1603 	 * here.
1604 	 */
1605 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1606 	    (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1607 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1608 				     trf->iso_ctrl_tech);
1609 
1610 		trf->iso_ctrl = trf->iso_ctrl_tech;
1611 	}
1612 
1613 	return ret;
1614 }
1615 
1616 /* Since this is a target routine, several of the framing calls are
1617  * made between receiving the request and sending the response so they
1618  * should take effect until after the response is sent.  This is accomplished
1619  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1620  * handler.
1621  */
1622 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1623 {
1624 	u8 iso_ctrl = trf->iso_ctrl_tech;
1625 	int ret;
1626 
1627 	dev_dbg(trf->dev, "framing: %d\n", framing);
1628 
1629 	switch (framing) {
1630 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1631 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1632 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1633 		break;
1634 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1635 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1636 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1637 		/* These ones are applied in the interrupt handler */
1638 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1639 		break;
1640 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1641 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1642 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1643 		break;
1644 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1645 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1646 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1647 		break;
1648 	default:
1649 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1650 		return -EINVAL;
1651 	}
1652 
1653 	trf->framing = framing;
1654 
1655 	if (iso_ctrl != trf->iso_ctrl) {
1656 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1657 		if (ret)
1658 			return ret;
1659 
1660 		trf->iso_ctrl = iso_ctrl;
1661 
1662 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1663 				     trf->modulator_sys_clk_ctrl);
1664 		if (ret)
1665 			return ret;
1666 	}
1667 
1668 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1669 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1670 				     trf->chip_status_ctrl |
1671 				     TRF7970A_CHIP_STATUS_RF_ON);
1672 		if (ret)
1673 			return ret;
1674 
1675 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1676 	}
1677 
1678 	return 0;
1679 }
1680 
1681 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1682 				    int param)
1683 {
1684 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1685 	int ret;
1686 
1687 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1688 
1689 	mutex_lock(&trf->lock);
1690 
1691 	trf->is_initiator = false;
1692 
1693 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1694 	    (trf->state == TRF7970A_ST_RF_OFF)) {
1695 		ret = trf7970a_switch_rf_on(trf);
1696 		if (ret)
1697 			goto err_unlock;
1698 	}
1699 
1700 	switch (type) {
1701 	case NFC_DIGITAL_CONFIG_RF_TECH:
1702 		ret = trf7970a_tg_config_rf_tech(trf, param);
1703 		break;
1704 	case NFC_DIGITAL_CONFIG_FRAMING:
1705 		ret = trf7970a_tg_config_framing(trf, param);
1706 		break;
1707 	default:
1708 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1709 		ret = -EINVAL;
1710 	}
1711 
1712 err_unlock:
1713 	mutex_unlock(&trf->lock);
1714 	return ret;
1715 }
1716 
1717 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1718 			       nfc_digital_cmd_complete_t cb, void *arg,
1719 			       bool mode_detect)
1720 {
1721 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1722 	int ret;
1723 
1724 	mutex_lock(&trf->lock);
1725 
1726 	if ((trf->state != TRF7970A_ST_IDLE) &&
1727 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1728 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1729 			trf->state);
1730 		ret = -EIO;
1731 		goto out_err;
1732 	}
1733 
1734 	if (trf->aborting) {
1735 		dev_dbg(trf->dev, "Abort process complete\n");
1736 		trf->aborting = false;
1737 		ret = -ECANCELED;
1738 		goto out_err;
1739 	}
1740 
1741 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1742 					 GFP_KERNEL);
1743 	if (!trf->rx_skb) {
1744 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1745 		ret = -ENOMEM;
1746 		goto out_err;
1747 	}
1748 
1749 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1750 			     TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1751 			     TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1752 			     TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1753 			     TRF7970A_RX_SPECIAL_SETTINGS_C212);
1754 	if (ret)
1755 		goto out_err;
1756 
1757 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1758 			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1759 	if (ret)
1760 		goto out_err;
1761 
1762 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1763 			     TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1764 	if (ret)
1765 		goto out_err;
1766 
1767 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1768 			     TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1769 	if (ret)
1770 		goto out_err;
1771 
1772 	trf->ddev = ddev;
1773 	trf->cb = cb;
1774 	trf->cb_arg = arg;
1775 	trf->timeout = timeout;
1776 	trf->ignore_timeout = false;
1777 
1778 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1779 	if (ret)
1780 		goto out_err;
1781 
1782 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1783 				   TRF7970A_ST_LISTENING;
1784 
1785 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1786 
1787 out_err:
1788 	mutex_unlock(&trf->lock);
1789 	return ret;
1790 }
1791 
1792 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1793 			      nfc_digital_cmd_complete_t cb, void *arg)
1794 {
1795 	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1796 
1797 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1798 		trf->state, timeout);
1799 
1800 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1801 }
1802 
1803 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1804 				 u16 timeout, nfc_digital_cmd_complete_t cb,
1805 				 void *arg)
1806 {
1807 	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1808 	int ret;
1809 
1810 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1811 		trf->state, timeout);
1812 
1813 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1814 				       NFC_DIGITAL_RF_TECH_106A);
1815 	if (ret)
1816 		return ret;
1817 
1818 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1819 				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1820 	if (ret)
1821 		return ret;
1822 
1823 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1824 }
1825 
1826 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1827 {
1828 	const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1829 
1830 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1831 		trf->state, trf->md_rf_tech);
1832 
1833 	*rf_tech = trf->md_rf_tech;
1834 
1835 	return 0;
1836 }
1837 
1838 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1839 {
1840 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1841 
1842 	dev_dbg(trf->dev, "Abort process initiated\n");
1843 
1844 	mutex_lock(&trf->lock);
1845 
1846 	switch (trf->state) {
1847 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1848 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1849 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1850 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1851 		trf->aborting = true;
1852 		break;
1853 	case TRF7970A_ST_LISTENING:
1854 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1855 		trf7970a_send_err_upstream(trf, -ECANCELED);
1856 		dev_dbg(trf->dev, "Abort process complete\n");
1857 		break;
1858 	default:
1859 		break;
1860 	}
1861 
1862 	mutex_unlock(&trf->lock);
1863 }
1864 
1865 static const struct nfc_digital_ops trf7970a_nfc_ops = {
1866 	.in_configure_hw	= trf7970a_in_configure_hw,
1867 	.in_send_cmd		= trf7970a_send_cmd,
1868 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1869 	.tg_send_cmd		= trf7970a_send_cmd,
1870 	.tg_listen		= trf7970a_tg_listen,
1871 	.tg_listen_md		= trf7970a_tg_listen_md,
1872 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1873 	.switch_rf		= trf7970a_switch_rf,
1874 	.abort_cmd		= trf7970a_abort_cmd,
1875 };
1876 
1877 static int trf7970a_power_up(struct trf7970a *trf)
1878 {
1879 	int ret;
1880 
1881 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1882 
1883 	if (trf->state != TRF7970A_ST_PWR_OFF)
1884 		return 0;
1885 
1886 	ret = regulator_enable(trf->regulator);
1887 	if (ret) {
1888 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1889 		return ret;
1890 	}
1891 
1892 	usleep_range(5000, 6000);
1893 
1894 	if (trf->en2_gpiod &&
1895 	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1896 		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1897 		usleep_range(1000, 2000);
1898 	}
1899 
1900 	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1901 
1902 	usleep_range(20000, 21000);
1903 
1904 	trf->state = TRF7970A_ST_RF_OFF;
1905 
1906 	return 0;
1907 }
1908 
1909 static int trf7970a_power_down(struct trf7970a *trf)
1910 {
1911 	int ret;
1912 
1913 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1914 
1915 	if (trf->state == TRF7970A_ST_PWR_OFF)
1916 		return 0;
1917 
1918 	if (trf->state != TRF7970A_ST_RF_OFF) {
1919 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1920 			trf->state);
1921 		return -EBUSY;
1922 	}
1923 
1924 	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1925 
1926 	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1927 		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1928 
1929 	ret = regulator_disable(trf->regulator);
1930 	if (ret)
1931 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1932 			ret);
1933 
1934 	trf->state = TRF7970A_ST_PWR_OFF;
1935 
1936 	return ret;
1937 }
1938 
1939 static int trf7970a_startup(struct trf7970a *trf)
1940 {
1941 	int ret;
1942 
1943 	ret = trf7970a_power_up(trf);
1944 	if (ret)
1945 		return ret;
1946 
1947 	pm_runtime_set_active(trf->dev);
1948 	pm_runtime_enable(trf->dev);
1949 	pm_runtime_mark_last_busy(trf->dev);
1950 
1951 	return 0;
1952 }
1953 
1954 static void trf7970a_shutdown(struct trf7970a *trf)
1955 {
1956 	switch (trf->state) {
1957 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1958 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1959 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1960 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1961 	case TRF7970A_ST_LISTENING:
1962 		trf7970a_send_err_upstream(trf, -ECANCELED);
1963 		fallthrough;
1964 	case TRF7970A_ST_IDLE:
1965 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1966 		trf7970a_switch_rf_off(trf);
1967 		break;
1968 	default:
1969 		break;
1970 	}
1971 
1972 	pm_runtime_disable(trf->dev);
1973 	pm_runtime_set_suspended(trf->dev);
1974 
1975 	trf7970a_power_down(trf);
1976 }
1977 
1978 static int trf7970a_get_autosuspend_delay(const struct device_node *np)
1979 {
1980 	int autosuspend_delay, ret;
1981 
1982 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1983 	if (ret)
1984 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1985 
1986 	return autosuspend_delay;
1987 }
1988 
1989 static int trf7970a_probe(struct spi_device *spi)
1990 {
1991 	const struct device_node *np = spi->dev.of_node;
1992 	struct trf7970a *trf;
1993 	int uvolts, autosuspend_delay, ret;
1994 	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1995 
1996 	if (!np) {
1997 		dev_err(&spi->dev, "No Device Tree entry\n");
1998 		return -EINVAL;
1999 	}
2000 
2001 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2002 	if (!trf)
2003 		return -ENOMEM;
2004 
2005 	trf->state = TRF7970A_ST_PWR_OFF;
2006 	trf->dev = &spi->dev;
2007 	trf->spi = spi;
2008 
2009 	spi->mode = SPI_MODE_1;
2010 	spi->bits_per_word = 8;
2011 
2012 	ret = spi_setup(spi);
2013 	if (ret < 0) {
2014 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2015 		return ret;
2016 	}
2017 
2018 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2019 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2020 
2021 	/* There are two enable pins - only EN must be present in the DT */
2022 	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2023 					     GPIOD_OUT_LOW);
2024 	if (IS_ERR(trf->en_gpiod)) {
2025 		dev_err(trf->dev, "No EN GPIO property\n");
2026 		return PTR_ERR(trf->en_gpiod);
2027 	}
2028 
2029 	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2030 						       GPIOD_OUT_LOW);
2031 	if (!trf->en2_gpiod) {
2032 		dev_info(trf->dev, "No EN2 GPIO property\n");
2033 	} else if (IS_ERR(trf->en2_gpiod)) {
2034 		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2035 			PTR_ERR(trf->en2_gpiod));
2036 		return PTR_ERR(trf->en2_gpiod);
2037 	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2038 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2039 	}
2040 
2041 	of_property_read_u32(np, "clock-frequency", &clk_freq);
2042 	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2043 	    (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2044 		dev_err(trf->dev,
2045 			"clock-frequency (%u Hz) unsupported\n", clk_freq);
2046 		return -EINVAL;
2047 	}
2048 
2049 	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2050 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2051 		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2052 	} else {
2053 		trf->modulator_sys_clk_ctrl = 0;
2054 	}
2055 
2056 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2057 					trf7970a_irq,
2058 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2059 					"trf7970a", trf);
2060 	if (ret) {
2061 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2062 		return ret;
2063 	}
2064 
2065 	mutex_init(&trf->lock);
2066 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2067 
2068 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2069 	if (IS_ERR(trf->regulator)) {
2070 		ret = PTR_ERR(trf->regulator);
2071 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2072 		goto err_destroy_lock;
2073 	}
2074 
2075 	ret = regulator_enable(trf->regulator);
2076 	if (ret) {
2077 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2078 		goto err_destroy_lock;
2079 	}
2080 
2081 	uvolts = regulator_get_voltage(trf->regulator);
2082 	if (uvolts > 4000000)
2083 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2084 
2085 	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2086 	if (IS_ERR(trf->regulator)) {
2087 		ret = PTR_ERR(trf->regulator);
2088 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2089 		goto err_destroy_lock;
2090 	}
2091 
2092 	ret = regulator_enable(trf->regulator);
2093 	if (ret) {
2094 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2095 		goto err_destroy_lock;
2096 	}
2097 
2098 	if (regulator_get_voltage(trf->regulator) == 1800000) {
2099 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2100 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2101 	}
2102 
2103 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2104 						TRF7970A_SUPPORTED_PROTOCOLS,
2105 						NFC_DIGITAL_DRV_CAPS_IN_CRC |
2106 						NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2107 						0);
2108 	if (!trf->ddev) {
2109 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2110 		ret = -ENOMEM;
2111 		goto err_disable_regulator;
2112 	}
2113 
2114 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2115 	nfc_digital_set_drvdata(trf->ddev, trf);
2116 	spi_set_drvdata(spi, trf);
2117 
2118 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2119 
2120 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2121 	pm_runtime_use_autosuspend(trf->dev);
2122 
2123 	ret = trf7970a_startup(trf);
2124 	if (ret)
2125 		goto err_free_ddev;
2126 
2127 	ret = nfc_digital_register_device(trf->ddev);
2128 	if (ret) {
2129 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2130 			ret);
2131 		goto err_shutdown;
2132 	}
2133 
2134 	return 0;
2135 
2136 err_shutdown:
2137 	trf7970a_shutdown(trf);
2138 err_free_ddev:
2139 	nfc_digital_free_device(trf->ddev);
2140 err_disable_regulator:
2141 	regulator_disable(trf->regulator);
2142 err_destroy_lock:
2143 	mutex_destroy(&trf->lock);
2144 	return ret;
2145 }
2146 
2147 static void trf7970a_remove(struct spi_device *spi)
2148 {
2149 	struct trf7970a *trf = spi_get_drvdata(spi);
2150 
2151 	mutex_lock(&trf->lock);
2152 
2153 	trf7970a_shutdown(trf);
2154 
2155 	mutex_unlock(&trf->lock);
2156 
2157 	nfc_digital_unregister_device(trf->ddev);
2158 	nfc_digital_free_device(trf->ddev);
2159 
2160 	regulator_disable(trf->regulator);
2161 
2162 	mutex_destroy(&trf->lock);
2163 }
2164 
2165 #ifdef CONFIG_PM_SLEEP
2166 static int trf7970a_suspend(struct device *dev)
2167 {
2168 	struct spi_device *spi = to_spi_device(dev);
2169 	struct trf7970a *trf = spi_get_drvdata(spi);
2170 
2171 	mutex_lock(&trf->lock);
2172 
2173 	trf7970a_shutdown(trf);
2174 
2175 	mutex_unlock(&trf->lock);
2176 
2177 	return 0;
2178 }
2179 
2180 static int trf7970a_resume(struct device *dev)
2181 {
2182 	struct spi_device *spi = to_spi_device(dev);
2183 	struct trf7970a *trf = spi_get_drvdata(spi);
2184 	int ret;
2185 
2186 	mutex_lock(&trf->lock);
2187 
2188 	ret = trf7970a_startup(trf);
2189 
2190 	mutex_unlock(&trf->lock);
2191 
2192 	return ret;
2193 }
2194 #endif
2195 
2196 #ifdef CONFIG_PM
2197 static int trf7970a_pm_runtime_suspend(struct device *dev)
2198 {
2199 	struct spi_device *spi = to_spi_device(dev);
2200 	struct trf7970a *trf = spi_get_drvdata(spi);
2201 	int ret;
2202 
2203 	mutex_lock(&trf->lock);
2204 
2205 	ret = trf7970a_power_down(trf);
2206 
2207 	mutex_unlock(&trf->lock);
2208 
2209 	return ret;
2210 }
2211 
2212 static int trf7970a_pm_runtime_resume(struct device *dev)
2213 {
2214 	struct spi_device *spi = to_spi_device(dev);
2215 	struct trf7970a *trf = spi_get_drvdata(spi);
2216 	int ret;
2217 
2218 	ret = trf7970a_power_up(trf);
2219 	if (!ret)
2220 		pm_runtime_mark_last_busy(dev);
2221 
2222 	return ret;
2223 }
2224 #endif
2225 
2226 static const struct dev_pm_ops trf7970a_pm_ops = {
2227 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2228 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2229 			   trf7970a_pm_runtime_resume, NULL)
2230 };
2231 
2232 static const struct of_device_id trf7970a_of_match[] __maybe_unused = {
2233 	{.compatible = "ti,trf7970a",},
2234 	{},
2235 };
2236 
2237 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2238 
2239 static const struct spi_device_id trf7970a_id_table[] = {
2240 	{"trf7970a", 0},
2241 	{}
2242 };
2243 
2244 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2245 
2246 static struct spi_driver trf7970a_spi_driver = {
2247 	.probe		= trf7970a_probe,
2248 	.remove		= trf7970a_remove,
2249 	.id_table	= trf7970a_id_table,
2250 	.driver	= {
2251 		.name		= "trf7970a",
2252 		.of_match_table	= of_match_ptr(trf7970a_of_match),
2253 		.pm		= &trf7970a_pm_ops,
2254 	},
2255 };
2256 
2257 module_spi_driver(trf7970a_spi_driver);
2258 
2259 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2260 MODULE_LICENSE("GPL v2");
2261 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2262