xref: /openbmc/linux/drivers/nfc/trf7970a.c (revision b737eecd)
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, 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, struct sk_buff *skb)
1391 {
1392 	u8 *req = skb->data;
1393 	u8 special_fcn_reg1, iso_ctrl;
1394 	int ret;
1395 
1396 	trf->issue_eof = false;
1397 
1398 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1399 	 * special functions register 1 is cleared; otherwise, its a write or
1400 	 * sector select command and '4_bit_RX' must be set.
1401 	 *
1402 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1403 	 * what speed to use.  Also, remember if the OPTION flag is set on
1404 	 * a Type 5 write or lock command so the driver will know that it
1405 	 * has to send an EOF in order to get a response.
1406 	 */
1407 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1408 	    (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1409 		if (req[0] == NFC_T2T_CMD_READ)
1410 			special_fcn_reg1 = 0;
1411 		else
1412 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1413 
1414 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1415 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1416 					     special_fcn_reg1);
1417 			if (ret)
1418 				return ret;
1419 
1420 			trf->special_fcn_reg1 = special_fcn_reg1;
1421 		}
1422 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1423 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1424 
1425 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1426 		case 0x00:
1427 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1428 			break;
1429 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1430 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1431 			break;
1432 		case ISO15693_REQ_FLAG_DATA_RATE:
1433 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1434 			break;
1435 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1436 		      ISO15693_REQ_FLAG_DATA_RATE):
1437 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1438 			break;
1439 		}
1440 
1441 		if (iso_ctrl != trf->iso_ctrl) {
1442 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1443 			if (ret)
1444 				return ret;
1445 
1446 			trf->iso_ctrl = iso_ctrl;
1447 		}
1448 
1449 		if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1450 		    trf7970a_is_iso15693_write_or_lock(req[1]) &&
1451 		    (req[0] & ISO15693_REQ_FLAG_OPTION))
1452 			trf->issue_eof = true;
1453 	}
1454 
1455 	return 0;
1456 }
1457 
1458 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1459 			     struct sk_buff *skb, u16 timeout,
1460 			     nfc_digital_cmd_complete_t cb, void *arg)
1461 {
1462 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1463 	u8 prefix[5];
1464 	unsigned int len;
1465 	int ret;
1466 	u8 status;
1467 
1468 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1469 		trf->state, timeout, skb->len);
1470 
1471 	if (skb->len > TRF7970A_TX_MAX)
1472 		return -EINVAL;
1473 
1474 	mutex_lock(&trf->lock);
1475 
1476 	if ((trf->state != TRF7970A_ST_IDLE) &&
1477 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1478 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1479 			trf->state);
1480 		ret = -EIO;
1481 		goto out_err;
1482 	}
1483 
1484 	if (trf->aborting) {
1485 		dev_dbg(trf->dev, "Abort process complete\n");
1486 		trf->aborting = false;
1487 		ret = -ECANCELED;
1488 		goto out_err;
1489 	}
1490 
1491 	if (timeout) {
1492 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1493 						 GFP_KERNEL);
1494 		if (!trf->rx_skb) {
1495 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1496 			ret = -ENOMEM;
1497 			goto out_err;
1498 		}
1499 	}
1500 
1501 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1502 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1503 		if (ret)
1504 			goto out_err;
1505 
1506 		trf->state = TRF7970A_ST_IDLE;
1507 	}
1508 
1509 	if (trf->is_initiator) {
1510 		ret = trf7970a_per_cmd_config(trf, skb);
1511 		if (ret)
1512 			goto out_err;
1513 	}
1514 
1515 	trf->ddev = ddev;
1516 	trf->tx_skb = skb;
1517 	trf->cb = cb;
1518 	trf->cb_arg = arg;
1519 	trf->timeout = timeout;
1520 	trf->ignore_timeout = false;
1521 
1522 	len = skb->len;
1523 
1524 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1525 	 * on what the current framing is, the address of the TX length byte 1
1526 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1527 	 * That totals 5 bytes.
1528 	 */
1529 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1530 	    TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1531 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1532 	    TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1533 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1534 
1535 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1536 		prefix[3] = 0x00;
1537 		prefix[4] = 0x0f;	/* 7 bits */
1538 	} else {
1539 		prefix[3] = (len & 0xf00) >> 4;
1540 		prefix[3] |= ((len & 0xf0) >> 4);
1541 		prefix[4] = ((len & 0x0f) << 4);
1542 	}
1543 
1544 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1545 
1546 	/* Clear possible spurious interrupt */
1547 	ret = trf7970a_read_irqstatus(trf, &status);
1548 	if (ret)
1549 		goto out_err;
1550 
1551 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1552 	if (ret) {
1553 		kfree_skb(trf->rx_skb);
1554 		trf->rx_skb = NULL;
1555 	}
1556 
1557 out_err:
1558 	mutex_unlock(&trf->lock);
1559 	return ret;
1560 }
1561 
1562 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1563 {
1564 	int ret = 0;
1565 
1566 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1567 
1568 	switch (tech) {
1569 	case NFC_DIGITAL_RF_TECH_106A:
1570 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1571 		    TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1572 		trf->modulator_sys_clk_ctrl =
1573 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1574 		    TRF7970A_MODULATOR_DEPTH_OOK;
1575 		break;
1576 	case NFC_DIGITAL_RF_TECH_212F:
1577 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1578 		    TRF7970A_ISO_CTRL_NFC_NFCF_212;
1579 		trf->modulator_sys_clk_ctrl =
1580 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1581 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1582 		break;
1583 	case NFC_DIGITAL_RF_TECH_424F:
1584 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1585 		    TRF7970A_ISO_CTRL_NFC_NFCF_424;
1586 		trf->modulator_sys_clk_ctrl =
1587 		    (trf->modulator_sys_clk_ctrl & 0xf8) |
1588 		    TRF7970A_MODULATOR_DEPTH_ASK10;
1589 		break;
1590 	default:
1591 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1592 		return -EINVAL;
1593 	}
1594 
1595 	trf->technology = tech;
1596 
1597 	/* Normally we write the ISO_CTRL register in
1598 	 * trf7970a_tg_config_framing() because the framing can change
1599 	 * the value written.  However, when sending a PSL RES,
1600 	 * digital_tg_send_psl_res_complete() doesn't call
1601 	 * trf7970a_tg_config_framing() so we must write the register
1602 	 * here.
1603 	 */
1604 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1605 	    (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1606 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1607 				     trf->iso_ctrl_tech);
1608 
1609 		trf->iso_ctrl = trf->iso_ctrl_tech;
1610 	}
1611 
1612 	return ret;
1613 }
1614 
1615 /* Since this is a target routine, several of the framing calls are
1616  * made between receiving the request and sending the response so they
1617  * should take effect until after the response is sent.  This is accomplished
1618  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1619  * handler.
1620  */
1621 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1622 {
1623 	u8 iso_ctrl = trf->iso_ctrl_tech;
1624 	int ret;
1625 
1626 	dev_dbg(trf->dev, "framing: %d\n", framing);
1627 
1628 	switch (framing) {
1629 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1630 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1631 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1632 		break;
1633 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1634 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1635 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1636 		/* These ones are applied in the interrupt handler */
1637 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1638 		break;
1639 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1640 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1641 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1642 		break;
1643 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1644 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1645 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1646 		break;
1647 	default:
1648 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1649 		return -EINVAL;
1650 	}
1651 
1652 	trf->framing = framing;
1653 
1654 	if (iso_ctrl != trf->iso_ctrl) {
1655 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1656 		if (ret)
1657 			return ret;
1658 
1659 		trf->iso_ctrl = iso_ctrl;
1660 
1661 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1662 				     trf->modulator_sys_clk_ctrl);
1663 		if (ret)
1664 			return ret;
1665 	}
1666 
1667 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1668 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1669 				     trf->chip_status_ctrl |
1670 				     TRF7970A_CHIP_STATUS_RF_ON);
1671 		if (ret)
1672 			return ret;
1673 
1674 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1675 	}
1676 
1677 	return 0;
1678 }
1679 
1680 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1681 				    int param)
1682 {
1683 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1684 	int ret;
1685 
1686 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1687 
1688 	mutex_lock(&trf->lock);
1689 
1690 	trf->is_initiator = false;
1691 
1692 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1693 	    (trf->state == TRF7970A_ST_RF_OFF)) {
1694 		ret = trf7970a_switch_rf_on(trf);
1695 		if (ret)
1696 			goto err_unlock;
1697 	}
1698 
1699 	switch (type) {
1700 	case NFC_DIGITAL_CONFIG_RF_TECH:
1701 		ret = trf7970a_tg_config_rf_tech(trf, param);
1702 		break;
1703 	case NFC_DIGITAL_CONFIG_FRAMING:
1704 		ret = trf7970a_tg_config_framing(trf, param);
1705 		break;
1706 	default:
1707 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1708 		ret = -EINVAL;
1709 	}
1710 
1711 err_unlock:
1712 	mutex_unlock(&trf->lock);
1713 	return ret;
1714 }
1715 
1716 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1717 			       nfc_digital_cmd_complete_t cb, void *arg,
1718 			       bool mode_detect)
1719 {
1720 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1721 	int ret;
1722 
1723 	mutex_lock(&trf->lock);
1724 
1725 	if ((trf->state != TRF7970A_ST_IDLE) &&
1726 	    (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1727 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1728 			trf->state);
1729 		ret = -EIO;
1730 		goto out_err;
1731 	}
1732 
1733 	if (trf->aborting) {
1734 		dev_dbg(trf->dev, "Abort process complete\n");
1735 		trf->aborting = false;
1736 		ret = -ECANCELED;
1737 		goto out_err;
1738 	}
1739 
1740 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1741 					 GFP_KERNEL);
1742 	if (!trf->rx_skb) {
1743 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1744 		ret = -ENOMEM;
1745 		goto out_err;
1746 	}
1747 
1748 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1749 			     TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1750 			     TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1751 			     TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1752 			     TRF7970A_RX_SPECIAL_SETTINGS_C212);
1753 	if (ret)
1754 		goto out_err;
1755 
1756 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1757 			     trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1758 	if (ret)
1759 		goto out_err;
1760 
1761 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1762 			     TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1763 	if (ret)
1764 		goto out_err;
1765 
1766 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1767 			     TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1768 	if (ret)
1769 		goto out_err;
1770 
1771 	trf->ddev = ddev;
1772 	trf->cb = cb;
1773 	trf->cb_arg = arg;
1774 	trf->timeout = timeout;
1775 	trf->ignore_timeout = false;
1776 
1777 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1778 	if (ret)
1779 		goto out_err;
1780 
1781 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1782 				   TRF7970A_ST_LISTENING;
1783 
1784 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1785 
1786 out_err:
1787 	mutex_unlock(&trf->lock);
1788 	return ret;
1789 }
1790 
1791 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1792 			      nfc_digital_cmd_complete_t cb, void *arg)
1793 {
1794 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1795 
1796 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1797 		trf->state, timeout);
1798 
1799 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1800 }
1801 
1802 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1803 				 u16 timeout, nfc_digital_cmd_complete_t cb,
1804 				 void *arg)
1805 {
1806 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1807 	int ret;
1808 
1809 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1810 		trf->state, timeout);
1811 
1812 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1813 				       NFC_DIGITAL_RF_TECH_106A);
1814 	if (ret)
1815 		return ret;
1816 
1817 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1818 				       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1819 	if (ret)
1820 		return ret;
1821 
1822 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1823 }
1824 
1825 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1826 {
1827 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1828 
1829 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1830 		trf->state, trf->md_rf_tech);
1831 
1832 	*rf_tech = trf->md_rf_tech;
1833 
1834 	return 0;
1835 }
1836 
1837 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1838 {
1839 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1840 
1841 	dev_dbg(trf->dev, "Abort process initiated\n");
1842 
1843 	mutex_lock(&trf->lock);
1844 
1845 	switch (trf->state) {
1846 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1847 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1848 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1849 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1850 		trf->aborting = true;
1851 		break;
1852 	case TRF7970A_ST_LISTENING:
1853 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1854 		trf7970a_send_err_upstream(trf, -ECANCELED);
1855 		dev_dbg(trf->dev, "Abort process complete\n");
1856 		break;
1857 	default:
1858 		break;
1859 	}
1860 
1861 	mutex_unlock(&trf->lock);
1862 }
1863 
1864 static struct nfc_digital_ops trf7970a_nfc_ops = {
1865 	.in_configure_hw	= trf7970a_in_configure_hw,
1866 	.in_send_cmd		= trf7970a_send_cmd,
1867 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1868 	.tg_send_cmd		= trf7970a_send_cmd,
1869 	.tg_listen		= trf7970a_tg_listen,
1870 	.tg_listen_md		= trf7970a_tg_listen_md,
1871 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1872 	.switch_rf		= trf7970a_switch_rf,
1873 	.abort_cmd		= trf7970a_abort_cmd,
1874 };
1875 
1876 static int trf7970a_power_up(struct trf7970a *trf)
1877 {
1878 	int ret;
1879 
1880 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1881 
1882 	if (trf->state != TRF7970A_ST_PWR_OFF)
1883 		return 0;
1884 
1885 	ret = regulator_enable(trf->regulator);
1886 	if (ret) {
1887 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1888 		return ret;
1889 	}
1890 
1891 	usleep_range(5000, 6000);
1892 
1893 	if (trf->en2_gpiod &&
1894 	    !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1895 		gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1896 		usleep_range(1000, 2000);
1897 	}
1898 
1899 	gpiod_set_value_cansleep(trf->en_gpiod, 1);
1900 
1901 	usleep_range(20000, 21000);
1902 
1903 	trf->state = TRF7970A_ST_RF_OFF;
1904 
1905 	return 0;
1906 }
1907 
1908 static int trf7970a_power_down(struct trf7970a *trf)
1909 {
1910 	int ret;
1911 
1912 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1913 
1914 	if (trf->state == TRF7970A_ST_PWR_OFF)
1915 		return 0;
1916 
1917 	if (trf->state != TRF7970A_ST_RF_OFF) {
1918 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1919 			trf->state);
1920 		return -EBUSY;
1921 	}
1922 
1923 	gpiod_set_value_cansleep(trf->en_gpiod, 0);
1924 
1925 	if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1926 		gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1927 
1928 	ret = regulator_disable(trf->regulator);
1929 	if (ret)
1930 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1931 			ret);
1932 
1933 	trf->state = TRF7970A_ST_PWR_OFF;
1934 
1935 	return ret;
1936 }
1937 
1938 static int trf7970a_startup(struct trf7970a *trf)
1939 {
1940 	int ret;
1941 
1942 	ret = trf7970a_power_up(trf);
1943 	if (ret)
1944 		return ret;
1945 
1946 	pm_runtime_set_active(trf->dev);
1947 	pm_runtime_enable(trf->dev);
1948 	pm_runtime_mark_last_busy(trf->dev);
1949 
1950 	return 0;
1951 }
1952 
1953 static void trf7970a_shutdown(struct trf7970a *trf)
1954 {
1955 	switch (trf->state) {
1956 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1957 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1958 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1959 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1960 	case TRF7970A_ST_LISTENING:
1961 		trf7970a_send_err_upstream(trf, -ECANCELED);
1962 		fallthrough;
1963 	case TRF7970A_ST_IDLE:
1964 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1965 		trf7970a_switch_rf_off(trf);
1966 		break;
1967 	default:
1968 		break;
1969 	}
1970 
1971 	pm_runtime_disable(trf->dev);
1972 	pm_runtime_set_suspended(trf->dev);
1973 
1974 	trf7970a_power_down(trf);
1975 }
1976 
1977 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1978 {
1979 	int autosuspend_delay, ret;
1980 
1981 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1982 	if (ret)
1983 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1984 
1985 	return autosuspend_delay;
1986 }
1987 
1988 static int trf7970a_probe(struct spi_device *spi)
1989 {
1990 	struct device_node *np = spi->dev.of_node;
1991 	struct trf7970a *trf;
1992 	int uvolts, autosuspend_delay, ret;
1993 	u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
1994 
1995 	if (!np) {
1996 		dev_err(&spi->dev, "No Device Tree entry\n");
1997 		return -EINVAL;
1998 	}
1999 
2000 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2001 	if (!trf)
2002 		return -ENOMEM;
2003 
2004 	trf->state = TRF7970A_ST_PWR_OFF;
2005 	trf->dev = &spi->dev;
2006 	trf->spi = spi;
2007 
2008 	spi->mode = SPI_MODE_1;
2009 	spi->bits_per_word = 8;
2010 
2011 	ret = spi_setup(spi);
2012 	if (ret < 0) {
2013 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2014 		return ret;
2015 	}
2016 
2017 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2018 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2019 
2020 	/* There are two enable pins - only EN must be present in the DT */
2021 	trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2022 					     GPIOD_OUT_LOW);
2023 	if (IS_ERR(trf->en_gpiod)) {
2024 		dev_err(trf->dev, "No EN GPIO property\n");
2025 		return PTR_ERR(trf->en_gpiod);
2026 	}
2027 
2028 	trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2029 						       GPIOD_OUT_LOW);
2030 	if (!trf->en2_gpiod) {
2031 		dev_info(trf->dev, "No EN2 GPIO property\n");
2032 	} else if (IS_ERR(trf->en2_gpiod)) {
2033 		dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2034 			PTR_ERR(trf->en2_gpiod));
2035 		return PTR_ERR(trf->en2_gpiod);
2036 	} else if (of_property_read_bool(np, "en2-rf-quirk")) {
2037 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2038 	}
2039 
2040 	of_property_read_u32(np, "clock-frequency", &clk_freq);
2041 	if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2042 	    (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2043 		dev_err(trf->dev,
2044 			"clock-frequency (%u Hz) unsupported\n", clk_freq);
2045 		return -EINVAL;
2046 	}
2047 
2048 	if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2049 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2050 		dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2051 	} else {
2052 		trf->modulator_sys_clk_ctrl = 0;
2053 	}
2054 
2055 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2056 					trf7970a_irq,
2057 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2058 					"trf7970a", trf);
2059 	if (ret) {
2060 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2061 		return ret;
2062 	}
2063 
2064 	mutex_init(&trf->lock);
2065 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2066 
2067 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2068 	if (IS_ERR(trf->regulator)) {
2069 		ret = PTR_ERR(trf->regulator);
2070 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2071 		goto err_destroy_lock;
2072 	}
2073 
2074 	ret = regulator_enable(trf->regulator);
2075 	if (ret) {
2076 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2077 		goto err_destroy_lock;
2078 	}
2079 
2080 	uvolts = regulator_get_voltage(trf->regulator);
2081 	if (uvolts > 4000000)
2082 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2083 
2084 	trf->regulator = devm_regulator_get(&spi->dev, "vdd-io");
2085 	if (IS_ERR(trf->regulator)) {
2086 		ret = PTR_ERR(trf->regulator);
2087 		dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2088 		goto err_destroy_lock;
2089 	}
2090 
2091 	ret = regulator_enable(trf->regulator);
2092 	if (ret) {
2093 		dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2094 		goto err_destroy_lock;
2095 	}
2096 
2097 	if (regulator_get_voltage(trf->regulator) == 1800000) {
2098 		trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2099 		dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2100 	}
2101 
2102 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2103 						TRF7970A_SUPPORTED_PROTOCOLS,
2104 						NFC_DIGITAL_DRV_CAPS_IN_CRC |
2105 						NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2106 						0);
2107 	if (!trf->ddev) {
2108 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2109 		ret = -ENOMEM;
2110 		goto err_disable_regulator;
2111 	}
2112 
2113 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2114 	nfc_digital_set_drvdata(trf->ddev, trf);
2115 	spi_set_drvdata(spi, trf);
2116 
2117 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2118 
2119 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2120 	pm_runtime_use_autosuspend(trf->dev);
2121 
2122 	ret = trf7970a_startup(trf);
2123 	if (ret)
2124 		goto err_free_ddev;
2125 
2126 	ret = nfc_digital_register_device(trf->ddev);
2127 	if (ret) {
2128 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2129 			ret);
2130 		goto err_shutdown;
2131 	}
2132 
2133 	return 0;
2134 
2135 err_shutdown:
2136 	trf7970a_shutdown(trf);
2137 err_free_ddev:
2138 	nfc_digital_free_device(trf->ddev);
2139 err_disable_regulator:
2140 	regulator_disable(trf->regulator);
2141 err_destroy_lock:
2142 	mutex_destroy(&trf->lock);
2143 	return ret;
2144 }
2145 
2146 static int trf7970a_remove(struct spi_device *spi)
2147 {
2148 	struct trf7970a *trf = spi_get_drvdata(spi);
2149 
2150 	mutex_lock(&trf->lock);
2151 
2152 	trf7970a_shutdown(trf);
2153 
2154 	mutex_unlock(&trf->lock);
2155 
2156 	nfc_digital_unregister_device(trf->ddev);
2157 	nfc_digital_free_device(trf->ddev);
2158 
2159 	regulator_disable(trf->regulator);
2160 
2161 	mutex_destroy(&trf->lock);
2162 
2163 	return 0;
2164 }
2165 
2166 #ifdef CONFIG_PM_SLEEP
2167 static int trf7970a_suspend(struct device *dev)
2168 {
2169 	struct spi_device *spi = to_spi_device(dev);
2170 	struct trf7970a *trf = spi_get_drvdata(spi);
2171 
2172 	dev_dbg(dev, "Suspend\n");
2173 
2174 	mutex_lock(&trf->lock);
2175 
2176 	trf7970a_shutdown(trf);
2177 
2178 	mutex_unlock(&trf->lock);
2179 
2180 	return 0;
2181 }
2182 
2183 static int trf7970a_resume(struct device *dev)
2184 {
2185 	struct spi_device *spi = to_spi_device(dev);
2186 	struct trf7970a *trf = spi_get_drvdata(spi);
2187 	int ret;
2188 
2189 	dev_dbg(dev, "Resume\n");
2190 
2191 	mutex_lock(&trf->lock);
2192 
2193 	ret = trf7970a_startup(trf);
2194 
2195 	mutex_unlock(&trf->lock);
2196 
2197 	return ret;
2198 }
2199 #endif
2200 
2201 #ifdef CONFIG_PM
2202 static int trf7970a_pm_runtime_suspend(struct device *dev)
2203 {
2204 	struct spi_device *spi = to_spi_device(dev);
2205 	struct trf7970a *trf = spi_get_drvdata(spi);
2206 	int ret;
2207 
2208 	dev_dbg(dev, "Runtime suspend\n");
2209 
2210 	mutex_lock(&trf->lock);
2211 
2212 	ret = trf7970a_power_down(trf);
2213 
2214 	mutex_unlock(&trf->lock);
2215 
2216 	return ret;
2217 }
2218 
2219 static int trf7970a_pm_runtime_resume(struct device *dev)
2220 {
2221 	struct spi_device *spi = to_spi_device(dev);
2222 	struct trf7970a *trf = spi_get_drvdata(spi);
2223 	int ret;
2224 
2225 	dev_dbg(dev, "Runtime resume\n");
2226 
2227 	ret = trf7970a_power_up(trf);
2228 	if (!ret)
2229 		pm_runtime_mark_last_busy(dev);
2230 
2231 	return ret;
2232 }
2233 #endif
2234 
2235 static const struct dev_pm_ops trf7970a_pm_ops = {
2236 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2237 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2238 			   trf7970a_pm_runtime_resume, NULL)
2239 };
2240 
2241 static const struct of_device_id trf7970a_of_match[] = {
2242 	{.compatible = "ti,trf7970a",},
2243 	{},
2244 };
2245 
2246 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2247 
2248 static const struct spi_device_id trf7970a_id_table[] = {
2249 	{"trf7970a", 0},
2250 	{}
2251 };
2252 
2253 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2254 
2255 static struct spi_driver trf7970a_spi_driver = {
2256 	.probe		= trf7970a_probe,
2257 	.remove		= trf7970a_remove,
2258 	.id_table	= trf7970a_id_table,
2259 	.driver	= {
2260 		.name		= "trf7970a",
2261 		.of_match_table	= of_match_ptr(trf7970a_of_match),
2262 		.pm		= &trf7970a_pm_ops,
2263 	},
2264 };
2265 
2266 module_spi_driver(trf7970a_spi_driver);
2267 
2268 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2269 MODULE_LICENSE("GPL v2");
2270 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2271