xref: /openbmc/linux/drivers/nfc/trf7970a.c (revision 2c684d89)
1 /*
2  * TI TRF7970a RFID/NFC Transceiver Driver
3  *
4  * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Author: Erick Macias <emacias@ti.com>
7  * Author: Felipe Balbi <balbi@ti.com>
8  * Author: Mark A. Greer <mgreer@animalcreek.com>
9  *
10  * This program is free software: you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2  of
12  * the License as published by the Free Software Foundation.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/netdevice.h>
18 #include <linux/interrupt.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/nfc.h>
21 #include <linux/skbuff.h>
22 #include <linux/delay.h>
23 #include <linux/gpio.h>
24 #include <linux/of.h>
25 #include <linux/of_gpio.h>
26 #include <linux/spi/spi.h>
27 #include <linux/regulator/consumer.h>
28 
29 #include <net/nfc/nfc.h>
30 #include <net/nfc/digital.h>
31 
32 /* There are 3 ways the host can communicate with the trf7970a:
33  * parallel mode, SPI with Slave Select (SS) mode, and SPI without
34  * SS mode.  The driver only supports the two SPI modes.
35  *
36  * The trf7970a is very timing sensitive and the VIN, EN2, and EN
37  * pins must asserted in that order and with specific delays in between.
38  * The delays used in the driver were provided by TI and have been
39  * confirmed to work with this driver.  There is a bug with the current
40  * version of the trf7970a that requires that EN2 remain low no matter
41  * what.  If it goes high, it will generate an RF field even when in
42  * passive target mode.  TI has indicated that the chip will work okay
43  * when EN2 is left low.  The 'en2-rf-quirk' device tree property
44  * indicates that trf7970a currently being used has the erratum and
45  * that EN2 must be kept low.
46  *
47  * Timeouts are implemented using the delayed workqueue kernel facility.
48  * Timeouts are required so things don't hang when there is no response
49  * from the trf7970a (or tag).  Using this mechanism creates a race with
50  * interrupts, however.  That is, an interrupt and a timeout could occur
51  * closely enough together that one is blocked by the mutex while the other
52  * executes.  When the timeout handler executes first and blocks the
53  * interrupt handler, it will eventually set the state to IDLE so the
54  * interrupt handler will check the state and exit with no harm done.
55  * When the interrupt handler executes first and blocks the timeout handler,
56  * the cancel_delayed_work() call will know that it didn't cancel the
57  * work item (i.e., timeout) and will return zero.  That return code is
58  * used by the timer handler to indicate that it should ignore the timeout
59  * once its unblocked.
60  *
61  * Aborting an active command isn't as simple as it seems because the only
62  * way to abort a command that's already been sent to the tag is so turn
63  * off power to the tag.  If we do that, though, we'd have to go through
64  * the entire anticollision procedure again but the digital layer doesn't
65  * support that.  So, if an abort is received before trf7970a_send_cmd()
66  * has sent the command to the tag, it simply returns -ECANCELED.  If the
67  * command has already been sent to the tag, then the driver continues
68  * normally and recieves the response data (or error) but just before
69  * sending the data upstream, it frees the rx_skb and sends -ECANCELED
70  * upstream instead.  If the command failed, that error will be sent
71  * upstream.
72  *
73  * When recieving data from a tag and the interrupt status register has
74  * only the SRX bit set, it means that all of the data has been received
75  * (once what's in the fifo has been read).  However, depending on timing
76  * an interrupt status with only the SRX bit set may not be recived.  In
77  * those cases, the timeout mechanism is used to wait 20 ms in case more
78  * data arrives.  After 20 ms, it is assumed that all of the data has been
79  * received and the accumulated rx data is sent upstream.  The
80  * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
81  * (i.e., it indicates that some data has been received but we're not sure
82  * if there is more coming so a timeout in this state means all data has
83  * been received and there isn't an error).  The delay is 20 ms since delays
84  * of ~16 ms have been observed during testing.
85  *
86  * When transmitting a frame larger than the FIFO size (127 bytes), the
87  * driver will wait 20 ms for the FIFO to drain past the low-watermark
88  * and generate an interrupt.  The low-watermark set to 32 bytes so the
89  * interrupt should fire after 127 - 32 = 95 bytes have been sent.  At
90  * the lowest possible bit rate (6.62 kbps for 15693), it will take up
91  * to ~14.35 ms so 20 ms is used for the timeout.
92  *
93  * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
94  * Having only 4 bits in the FIFO won't normally generate an interrupt so
95  * driver enables the '4_bit_RX' bit of the Special Functions register 1
96  * to cause an interrupt in that case.  Leaving that bit for a read command
97  * messes up the data returned so it is only enabled when the framing is
98  * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
99  * Unfortunately, that means that the driver has to peek into tx frames
100  * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'.  This is done by
101  * the trf7970a_per_cmd_config() routine.
102  *
103  * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
104  * frequencies and whether to use low or high data rates in the flags byte
105  * of the frame.  This means that the driver has to peek at all 15693 frames
106  * to determine what speed to set the communication to.  In addition, write
107  * and lock commands use the OPTION flag to indicate that an EOF must be
108  * sent to the tag before it will send its response.  So the driver has to
109  * examine all frames for that reason too.
110  *
111  * It is unclear how long to wait before sending the EOF.  According to the
112  * Note under Table 1-1 in section 1.6 of
113  * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
114  * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
115  * enough so 20 ms is used.  So the timer is set to 40 ms - 20 ms to drain
116  * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
117  * ensure the wait is long enough before sending the EOF.  This seems to work
118  * reliably.
119  */
120 
121 #define TRF7970A_SUPPORTED_PROTOCOLS \
122 		(NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK |	\
123 		 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
124 		 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
125 
126 #define TRF7970A_AUTOSUSPEND_DELAY		30000 /* 30 seconds */
127 
128 #define TRF7970A_RX_SKB_ALLOC_SIZE		256
129 
130 #define TRF7970A_FIFO_SIZE			127
131 
132 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
133 #define TRF7970A_TX_MAX				(4096 - 1)
134 
135 #define TRF7970A_WAIT_FOR_TX_IRQ		20
136 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT	20
137 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT	20
138 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF	40
139 
140 /* Guard times for various RF technologies (in us) */
141 #define TRF7970A_GUARD_TIME_NFCA		5000
142 #define TRF7970A_GUARD_TIME_NFCB		5000
143 #define TRF7970A_GUARD_TIME_NFCF		20000
144 #define TRF7970A_GUARD_TIME_15693		1000
145 
146 /* Quirks */
147 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
148  * read continuous command for IRQ Status and Collision Position registers.
149  */
150 #define TRF7970A_QUIRK_IRQ_STATUS_READ		BIT(0)
151 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW	BIT(1)
152 #define TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE	BIT(2)
153 
154 /* Direct commands */
155 #define TRF7970A_CMD_IDLE			0x00
156 #define TRF7970A_CMD_SOFT_INIT			0x03
157 #define TRF7970A_CMD_RF_COLLISION		0x04
158 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N	0x05
159 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0	0x06
160 #define TRF7970A_CMD_FIFO_RESET			0x0f
161 #define TRF7970A_CMD_TRANSMIT_NO_CRC		0x10
162 #define TRF7970A_CMD_TRANSMIT			0x11
163 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC	0x12
164 #define TRF7970A_CMD_DELAY_TRANSMIT		0x13
165 #define TRF7970A_CMD_EOF			0x14
166 #define TRF7970A_CMD_CLOSE_SLOT			0x15
167 #define TRF7970A_CMD_BLOCK_RX			0x16
168 #define TRF7970A_CMD_ENABLE_RX			0x17
169 #define TRF7970A_CMD_TEST_INT_RF		0x18
170 #define TRF7970A_CMD_TEST_EXT_RF		0x19
171 #define TRF7970A_CMD_RX_GAIN_ADJUST		0x1a
172 
173 /* Bits determining whether its a direct command or register R/W,
174  * whether to use a continuous SPI transaction or not, and the actual
175  * direct cmd opcode or regster address.
176  */
177 #define TRF7970A_CMD_BIT_CTRL			BIT(7)
178 #define TRF7970A_CMD_BIT_RW			BIT(6)
179 #define TRF7970A_CMD_BIT_CONTINUOUS		BIT(5)
180 #define TRF7970A_CMD_BIT_OPCODE(opcode)		((opcode) & 0x1f)
181 
182 /* Registers addresses */
183 #define TRF7970A_CHIP_STATUS_CTRL		0x00
184 #define TRF7970A_ISO_CTRL			0x01
185 #define TRF7970A_ISO14443B_TX_OPTIONS		0x02
186 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS	0x03
187 #define TRF7970A_TX_TIMER_SETTING_H_BYTE	0x04
188 #define TRF7970A_TX_TIMER_SETTING_L_BYTE	0x05
189 #define TRF7970A_TX_PULSE_LENGTH_CTRL		0x06
190 #define TRF7970A_RX_NO_RESPONSE_WAIT		0x07
191 #define TRF7970A_RX_WAIT_TIME			0x08
192 #define TRF7970A_MODULATOR_SYS_CLK_CTRL		0x09
193 #define TRF7970A_RX_SPECIAL_SETTINGS		0x0a
194 #define TRF7970A_REG_IO_CTRL			0x0b
195 #define TRF7970A_IRQ_STATUS			0x0c
196 #define TRF7970A_COLLISION_IRQ_MASK		0x0d
197 #define TRF7970A_COLLISION_POSITION		0x0e
198 #define TRF7970A_RSSI_OSC_STATUS		0x0f
199 #define TRF7970A_SPECIAL_FCN_REG1		0x10
200 #define TRF7970A_SPECIAL_FCN_REG2		0x11
201 #define TRF7970A_RAM1				0x12
202 #define TRF7970A_RAM2				0x13
203 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS	0x14
204 #define TRF7970A_NFC_LOW_FIELD_LEVEL		0x16
205 #define TRF7970A_NFCID1				0x17
206 #define TRF7970A_NFC_TARGET_LEVEL		0x18
207 #define TRF79070A_NFC_TARGET_PROTOCOL		0x19
208 #define TRF7970A_TEST_REGISTER1			0x1a
209 #define TRF7970A_TEST_REGISTER2			0x1b
210 #define TRF7970A_FIFO_STATUS			0x1c
211 #define TRF7970A_TX_LENGTH_BYTE1		0x1d
212 #define TRF7970A_TX_LENGTH_BYTE2		0x1e
213 #define TRF7970A_FIFO_IO_REGISTER		0x1f
214 
215 /* Chip Status Control Register Bits */
216 #define TRF7970A_CHIP_STATUS_VRS5_3		BIT(0)
217 #define TRF7970A_CHIP_STATUS_REC_ON		BIT(1)
218 #define TRF7970A_CHIP_STATUS_AGC_ON		BIT(2)
219 #define TRF7970A_CHIP_STATUS_PM_ON		BIT(3)
220 #define TRF7970A_CHIP_STATUS_RF_PWR		BIT(4)
221 #define TRF7970A_CHIP_STATUS_RF_ON		BIT(5)
222 #define TRF7970A_CHIP_STATUS_DIRECT		BIT(6)
223 #define TRF7970A_CHIP_STATUS_STBY		BIT(7)
224 
225 /* ISO Control Register Bits */
226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662	0x00
227 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662	0x01
228 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648	0x02
229 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648	0x03
230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a	0x04
231 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667	0x05
232 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669	0x06
233 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669	0x07
234 #define TRF7970A_ISO_CTRL_14443A_106		0x08
235 #define TRF7970A_ISO_CTRL_14443A_212		0x09
236 #define TRF7970A_ISO_CTRL_14443A_424		0x0a
237 #define TRF7970A_ISO_CTRL_14443A_848		0x0b
238 #define TRF7970A_ISO_CTRL_14443B_106		0x0c
239 #define TRF7970A_ISO_CTRL_14443B_212		0x0d
240 #define TRF7970A_ISO_CTRL_14443B_424		0x0e
241 #define TRF7970A_ISO_CTRL_14443B_848		0x0f
242 #define TRF7970A_ISO_CTRL_FELICA_212		0x1a
243 #define TRF7970A_ISO_CTRL_FELICA_424		0x1b
244 #define TRF7970A_ISO_CTRL_NFC_NFCA_106		0x01
245 #define TRF7970A_ISO_CTRL_NFC_NFCF_212		0x02
246 #define TRF7970A_ISO_CTRL_NFC_NFCF_424		0x03
247 #define TRF7970A_ISO_CTRL_NFC_CE_14443A		0x00
248 #define TRF7970A_ISO_CTRL_NFC_CE_14443B		0x01
249 #define TRF7970A_ISO_CTRL_NFC_CE		BIT(2)
250 #define TRF7970A_ISO_CTRL_NFC_ACTIVE		BIT(3)
251 #define TRF7970A_ISO_CTRL_NFC_INITIATOR		BIT(4)
252 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE	BIT(5)
253 #define TRF7970A_ISO_CTRL_RFID			BIT(5)
254 #define TRF7970A_ISO_CTRL_DIR_MODE		BIT(6)
255 #define TRF7970A_ISO_CTRL_RX_CRC_N		BIT(7)	/* true == No CRC */
256 
257 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK	0x1f
258 
259 /* Modulator and SYS_CLK Control Register Bits */
260 #define TRF7970A_MODULATOR_DEPTH(n)		((n) & 0x7)
261 #define TRF7970A_MODULATOR_DEPTH_ASK10		(TRF7970A_MODULATOR_DEPTH(0))
262 #define TRF7970A_MODULATOR_DEPTH_OOK		(TRF7970A_MODULATOR_DEPTH(1))
263 #define TRF7970A_MODULATOR_DEPTH_ASK7		(TRF7970A_MODULATOR_DEPTH(2))
264 #define TRF7970A_MODULATOR_DEPTH_ASK8_5		(TRF7970A_MODULATOR_DEPTH(3))
265 #define TRF7970A_MODULATOR_DEPTH_ASK13		(TRF7970A_MODULATOR_DEPTH(4))
266 #define TRF7970A_MODULATOR_DEPTH_ASK16		(TRF7970A_MODULATOR_DEPTH(5))
267 #define TRF7970A_MODULATOR_DEPTH_ASK22		(TRF7970A_MODULATOR_DEPTH(6))
268 #define TRF7970A_MODULATOR_DEPTH_ASK30		(TRF7970A_MODULATOR_DEPTH(7))
269 #define TRF7970A_MODULATOR_EN_ANA		BIT(3)
270 #define TRF7970A_MODULATOR_CLK(n)		(((n) & 0x3) << 4)
271 #define TRF7970A_MODULATOR_CLK_DISABLED		(TRF7970A_MODULATOR_CLK(0))
272 #define TRF7970A_MODULATOR_CLK_3_6		(TRF7970A_MODULATOR_CLK(1))
273 #define TRF7970A_MODULATOR_CLK_6_13		(TRF7970A_MODULATOR_CLK(2))
274 #define TRF7970A_MODULATOR_CLK_13_27		(TRF7970A_MODULATOR_CLK(3))
275 #define TRF7970A_MODULATOR_EN_OOK		BIT(6)
276 #define TRF7970A_MODULATOR_27MHZ		BIT(7)
277 
278 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM	BIT(0)
279 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR	BIT(1)
280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB	(0x0 << 2)
281 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB	(0x1 << 2)
282 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB	(0x2 << 2)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB	(0x3 << 2)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT	BIT(4)
285 #define TRF7970A_RX_SPECIAL_SETTINGS_M848	BIT(5)
286 #define TRF7970A_RX_SPECIAL_SETTINGS_C424	BIT(6)
287 #define TRF7970A_RX_SPECIAL_SETTINGS_C212	BIT(7)
288 
289 #define TRF7970A_REG_IO_CTRL_VRS(v)		((v) & 0x07)
290 #define TRF7970A_REG_IO_CTRL_IO_LOW		BIT(5)
291 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA		BIT(6)
292 #define TRF7970A_REG_IO_CTRL_AUTO_REG		BIT(7)
293 
294 /* IRQ Status Register Bits */
295 #define TRF7970A_IRQ_STATUS_NORESP		BIT(0) /* ISO15693 only */
296 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR	BIT(0)
297 #define TRF7970A_IRQ_STATUS_COL			BIT(1)
298 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR	BIT(2)
299 #define TRF7970A_IRQ_STATUS_NFC_RF		BIT(2)
300 #define TRF7970A_IRQ_STATUS_PARITY_ERROR	BIT(3)
301 #define TRF7970A_IRQ_STATUS_NFC_SDD		BIT(3)
302 #define TRF7970A_IRQ_STATUS_CRC_ERROR		BIT(4)
303 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR	BIT(4)
304 #define TRF7970A_IRQ_STATUS_FIFO		BIT(5)
305 #define TRF7970A_IRQ_STATUS_SRX			BIT(6)
306 #define TRF7970A_IRQ_STATUS_TX			BIT(7)
307 
308 #define TRF7970A_IRQ_STATUS_ERROR				\
309 		(TRF7970A_IRQ_STATUS_COL |			\
310 		 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR |	\
311 		 TRF7970A_IRQ_STATUS_PARITY_ERROR |		\
312 		 TRF7970A_IRQ_STATUS_CRC_ERROR)
313 
314 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK	(BIT(2) | BIT(1) | BIT(0))
315 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK	(BIT(5) | BIT(4) | BIT(3))
316 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK	BIT(6)
317 
318 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6		BIT(0)
319 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL		BIT(1)
320 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX		BIT(2)
321 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE		BIT(3)
322 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US	BIT(4)
323 #define TRF7970A_SPECIAL_FCN_REG1_PAR43			BIT(5)
324 
325 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124	(0x0 << 2)
326 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120	(0x1 << 2)
327 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112	(0x2 << 2)
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96	(0x3 << 2)
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4	0x0
330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8	0x1
331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16	0x2
332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32	0x3
333 
334 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v)	((v) & 0x07)
335 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS	BIT(7)
336 
337 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v)	((v) & 0x07)
338 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF		BIT(3)
339 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN	BIT(5)
340 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES	(0x0 << 6)
341 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES	(0x1 << 6)
342 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES	(0x2 << 6)
343 
344 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106		BIT(0)
345 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212		BIT(1)
346 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424		(BIT(0) | BIT(1))
347 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B	BIT(2)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106		BIT(3)
349 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA		BIT(4)
350 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L		BIT(6)
351 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H		BIT(7)
352 
353 #define TRF79070A_NFC_TARGET_PROTOCOL_106A		\
354 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
355 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
356 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 |	\
357 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
358 
359 #define TRF79070A_NFC_TARGET_PROTOCOL_106B		\
360 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
361 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
362 	  TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B |	\
363 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
364 
365 #define TRF79070A_NFC_TARGET_PROTOCOL_212F		\
366 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
367 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
368 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
369 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
370 
371 #define TRF79070A_NFC_TARGET_PROTOCOL_424F		\
372 	 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H |		\
373 	  TRF79070A_NFC_TARGET_PROTOCOL_RF_L |		\
374 	  TRF79070A_NFC_TARGET_PROTOCOL_FELICA |	\
375 	  TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
376 
377 #define TRF7970A_FIFO_STATUS_OVERFLOW		BIT(7)
378 
379 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
380 #define NFC_T2T_CMD_READ			0x30
381 
382 /* ISO 15693 commands codes */
383 #define ISO15693_CMD_INVENTORY			0x01
384 #define ISO15693_CMD_READ_SINGLE_BLOCK		0x20
385 #define ISO15693_CMD_WRITE_SINGLE_BLOCK		0x21
386 #define ISO15693_CMD_LOCK_BLOCK			0x22
387 #define ISO15693_CMD_READ_MULTIPLE_BLOCK	0x23
388 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK	0x24
389 #define ISO15693_CMD_SELECT			0x25
390 #define ISO15693_CMD_RESET_TO_READY		0x26
391 #define ISO15693_CMD_WRITE_AFI			0x27
392 #define ISO15693_CMD_LOCK_AFI			0x28
393 #define ISO15693_CMD_WRITE_DSFID		0x29
394 #define ISO15693_CMD_LOCK_DSFID			0x2a
395 #define ISO15693_CMD_GET_SYSTEM_INFO		0x2b
396 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS	0x2c
397 
398 /* ISO 15693 request and response flags */
399 #define ISO15693_REQ_FLAG_SUB_CARRIER		BIT(0)
400 #define ISO15693_REQ_FLAG_DATA_RATE		BIT(1)
401 #define ISO15693_REQ_FLAG_INVENTORY		BIT(2)
402 #define ISO15693_REQ_FLAG_PROTOCOL_EXT		BIT(3)
403 #define ISO15693_REQ_FLAG_SELECT		BIT(4)
404 #define ISO15693_REQ_FLAG_AFI			BIT(4)
405 #define ISO15693_REQ_FLAG_ADDRESS		BIT(5)
406 #define ISO15693_REQ_FLAG_NB_SLOTS		BIT(5)
407 #define ISO15693_REQ_FLAG_OPTION		BIT(6)
408 
409 #define ISO15693_REQ_FLAG_SPEED_MASK \
410 		(ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
411 
412 enum trf7970a_state {
413 	TRF7970A_ST_PWR_OFF,
414 	TRF7970A_ST_RF_OFF,
415 	TRF7970A_ST_IDLE,
416 	TRF7970A_ST_IDLE_RX_BLOCKED,
417 	TRF7970A_ST_WAIT_FOR_TX_FIFO,
418 	TRF7970A_ST_WAIT_FOR_RX_DATA,
419 	TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
420 	TRF7970A_ST_WAIT_TO_ISSUE_EOF,
421 	TRF7970A_ST_LISTENING,
422 	TRF7970A_ST_LISTENING_MD,
423 	TRF7970A_ST_MAX
424 };
425 
426 struct trf7970a {
427 	enum trf7970a_state		state;
428 	struct device			*dev;
429 	struct spi_device		*spi;
430 	struct regulator		*regulator;
431 	struct nfc_digital_dev		*ddev;
432 	u32				quirks;
433 	bool				is_initiator;
434 	bool				aborting;
435 	struct sk_buff			*tx_skb;
436 	struct sk_buff			*rx_skb;
437 	nfc_digital_cmd_complete_t	cb;
438 	void				*cb_arg;
439 	u8				chip_status_ctrl;
440 	u8				iso_ctrl;
441 	u8				iso_ctrl_tech;
442 	u8				modulator_sys_clk_ctrl;
443 	u8				special_fcn_reg1;
444 	unsigned int			guard_time;
445 	int				technology;
446 	int				framing;
447 	u8				md_rf_tech;
448 	u8				tx_cmd;
449 	bool				issue_eof;
450 	bool				adjust_resp_len;
451 	int				en2_gpio;
452 	int				en_gpio;
453 	struct mutex			lock;
454 	unsigned int			timeout;
455 	bool				ignore_timeout;
456 	struct delayed_work		timeout_work;
457 };
458 
459 
460 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
461 {
462 	u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
463 	int ret;
464 
465 	dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
466 
467 	ret = spi_write(trf->spi, &cmd, 1);
468 	if (ret)
469 		dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
470 				ret);
471 	return ret;
472 }
473 
474 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
475 {
476 	u8 addr = TRF7970A_CMD_BIT_RW | reg;
477 	int ret;
478 
479 	ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
480 	if (ret)
481 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
482 				ret);
483 
484 	dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
485 
486 	return ret;
487 }
488 
489 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf, size_t len)
490 {
491 	u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
492 	struct spi_transfer t[2];
493 	struct spi_message m;
494 	int ret;
495 
496 	dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
497 
498 	spi_message_init(&m);
499 
500 	memset(&t, 0, sizeof(t));
501 
502 	t[0].tx_buf = &addr;
503 	t[0].len = sizeof(addr);
504 	spi_message_add_tail(&t[0], &m);
505 
506 	t[1].rx_buf = buf;
507 	t[1].len = len;
508 	spi_message_add_tail(&t[1], &m);
509 
510 	ret = spi_sync(trf->spi, &m);
511 	if (ret)
512 		dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
513 				ret);
514 	return ret;
515 }
516 
517 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
518 {
519 	u8 buf[2] = { reg, val };
520 	int ret;
521 
522 	dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
523 
524 	ret = spi_write(trf->spi, buf, 2);
525 	if (ret)
526 		dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
527 				buf[0], buf[1], ret);
528 
529 	return ret;
530 }
531 
532 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
533 {
534 	int ret;
535 	u8 buf[2];
536 	u8 addr;
537 
538 	addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
539 
540 	if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
541 		addr |= TRF7970A_CMD_BIT_CONTINUOUS;
542 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
543 	} else {
544 		ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
545 	}
546 
547 	if (ret)
548 		dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
549 				__func__, ret);
550 	else
551 		*status = buf[0];
552 
553 	return ret;
554 }
555 
556 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
557 {
558 	int ret;
559 	u8 buf[2];
560 	u8 addr;
561 
562 	addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
563 		TRF7970A_CMD_BIT_CONTINUOUS;
564 
565 	ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
566 	if (ret)
567 		dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
568 				__func__, ret);
569 	else
570 		*target_proto = buf[0];
571 
572 	return ret;
573 }
574 
575 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
576 {
577 	int ret;
578 	u8 target_proto, tech;
579 
580 	ret = trf7970a_read_target_proto(trf, &target_proto);
581 	if (ret)
582 		return ret;
583 
584 	switch (target_proto) {
585 	case TRF79070A_NFC_TARGET_PROTOCOL_106A:
586 		tech = NFC_DIGITAL_RF_TECH_106A;
587 		break;
588 	case TRF79070A_NFC_TARGET_PROTOCOL_106B:
589 		tech = NFC_DIGITAL_RF_TECH_106B;
590 		break;
591 	case TRF79070A_NFC_TARGET_PROTOCOL_212F:
592 		tech = NFC_DIGITAL_RF_TECH_212F;
593 		break;
594 	case TRF79070A_NFC_TARGET_PROTOCOL_424F:
595 		tech = NFC_DIGITAL_RF_TECH_424F;
596 		break;
597 	default:
598 		dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
599 				__func__, target_proto);
600 		return -EIO;
601 	}
602 
603 	*rf_tech = tech;
604 
605 	return ret;
606 }
607 
608 static void trf7970a_send_upstream(struct trf7970a *trf)
609 {
610 	dev_kfree_skb_any(trf->tx_skb);
611 	trf->tx_skb = NULL;
612 
613 	if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
614 		print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
615 				16, 1, trf->rx_skb->data, trf->rx_skb->len,
616 				false);
617 
618 	trf->state = TRF7970A_ST_IDLE;
619 
620 	if (trf->aborting) {
621 		dev_dbg(trf->dev, "Abort process complete\n");
622 
623 		if (!IS_ERR(trf->rx_skb)) {
624 			kfree_skb(trf->rx_skb);
625 			trf->rx_skb = ERR_PTR(-ECANCELED);
626 		}
627 
628 		trf->aborting = false;
629 	}
630 
631 	if (trf->adjust_resp_len) {
632 		if (trf->rx_skb)
633 			skb_trim(trf->rx_skb, trf->rx_skb->len - 1);
634 
635 		trf->adjust_resp_len = false;
636 	}
637 
638 	trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
639 
640 	trf->rx_skb = NULL;
641 }
642 
643 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
644 {
645 	dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
646 
647 	cancel_delayed_work(&trf->timeout_work);
648 
649 	kfree_skb(trf->rx_skb);
650 	trf->rx_skb = ERR_PTR(errno);
651 
652 	trf7970a_send_upstream(trf);
653 }
654 
655 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
656 		unsigned int len, u8 *prefix, unsigned int prefix_len)
657 {
658 	struct spi_transfer t[2];
659 	struct spi_message m;
660 	unsigned int timeout;
661 	int ret;
662 
663 	print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
664 			16, 1, skb->data, len, false);
665 
666 	spi_message_init(&m);
667 
668 	memset(&t, 0, sizeof(t));
669 
670 	t[0].tx_buf = prefix;
671 	t[0].len = prefix_len;
672 	spi_message_add_tail(&t[0], &m);
673 
674 	t[1].tx_buf = skb->data;
675 	t[1].len = len;
676 	spi_message_add_tail(&t[1], &m);
677 
678 	ret = spi_sync(trf->spi, &m);
679 	if (ret) {
680 		dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
681 				ret);
682 		return ret;
683 	}
684 
685 	skb_pull(skb, len);
686 
687 	if (skb->len > 0) {
688 		trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
689 		timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
690 	} else {
691 		if (trf->issue_eof) {
692 			trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
693 			timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
694 		} else {
695 			trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
696 
697 			if (!trf->timeout)
698 				timeout = TRF7970A_WAIT_FOR_TX_IRQ;
699 			else
700 				timeout = trf->timeout;
701 		}
702 	}
703 
704 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
705 			trf->state);
706 
707 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
708 
709 	return 0;
710 }
711 
712 static void trf7970a_fill_fifo(struct trf7970a *trf)
713 {
714 	struct sk_buff *skb = trf->tx_skb;
715 	unsigned int len;
716 	int ret;
717 	u8 fifo_bytes;
718 	u8 prefix;
719 
720 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
721 	if (ret) {
722 		trf7970a_send_err_upstream(trf, ret);
723 		return;
724 	}
725 
726 	dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
727 
728 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
729 
730 	/* Calculate how much more data can be written to the fifo */
731 	len = TRF7970A_FIFO_SIZE - fifo_bytes;
732 	if (!len) {
733 		schedule_delayed_work(&trf->timeout_work,
734 			msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
735 		return;
736 	}
737 
738 	len = min(skb->len, len);
739 
740 	prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
741 
742 	ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
743 	if (ret)
744 		trf7970a_send_err_upstream(trf, ret);
745 }
746 
747 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
748 {
749 	struct sk_buff *skb = trf->rx_skb;
750 	int ret;
751 	u8 fifo_bytes;
752 
753 	if (status & TRF7970A_IRQ_STATUS_ERROR) {
754 		trf7970a_send_err_upstream(trf, -EIO);
755 		return;
756 	}
757 
758 	ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
759 	if (ret) {
760 		trf7970a_send_err_upstream(trf, ret);
761 		return;
762 	}
763 
764 	dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
765 
766 	fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
767 
768 	if (!fifo_bytes)
769 		goto no_rx_data;
770 
771 	if (fifo_bytes > skb_tailroom(skb)) {
772 		skb = skb_copy_expand(skb, skb_headroom(skb),
773 				max_t(int, fifo_bytes,
774 					TRF7970A_RX_SKB_ALLOC_SIZE),
775 				GFP_KERNEL);
776 		if (!skb) {
777 			trf7970a_send_err_upstream(trf, -ENOMEM);
778 			return;
779 		}
780 
781 		kfree_skb(trf->rx_skb);
782 		trf->rx_skb = skb;
783 	}
784 
785 	ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
786 			skb_put(skb, fifo_bytes), fifo_bytes);
787 	if (ret) {
788 		trf7970a_send_err_upstream(trf, ret);
789 		return;
790 	}
791 
792 	/* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
793 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
794 			(trf->special_fcn_reg1 ==
795 				 TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
796 		skb->data[0] >>= 4;
797 		status = TRF7970A_IRQ_STATUS_SRX;
798 	} else {
799 		trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
800 
801 		ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
802 		if (ret) {
803 			trf7970a_send_err_upstream(trf, ret);
804 			return;
805 		}
806 
807 		fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
808 
809 		/* If there are bytes in the FIFO, set status to '0' so
810 		 * the if stmt below doesn't fire and the driver will wait
811 		 * for the trf7970a to generate another RX interrupt.
812 		 */
813 		if (fifo_bytes)
814 			status = 0;
815 	}
816 
817 no_rx_data:
818 	if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
819 		trf7970a_send_upstream(trf);
820 		return;
821 	}
822 
823 	dev_dbg(trf->dev, "Setting timeout for %d ms\n",
824 			TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
825 
826 	schedule_delayed_work(&trf->timeout_work,
827 			msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
828 }
829 
830 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
831 {
832 	struct trf7970a *trf = dev_id;
833 	int ret;
834 	u8 status, fifo_bytes, iso_ctrl;
835 
836 	mutex_lock(&trf->lock);
837 
838 	if (trf->state == TRF7970A_ST_RF_OFF) {
839 		mutex_unlock(&trf->lock);
840 		return IRQ_NONE;
841 	}
842 
843 	ret = trf7970a_read_irqstatus(trf, &status);
844 	if (ret) {
845 		mutex_unlock(&trf->lock);
846 		return IRQ_NONE;
847 	}
848 
849 	dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
850 			status);
851 
852 	if (!status) {
853 		mutex_unlock(&trf->lock);
854 		return IRQ_NONE;
855 	}
856 
857 	switch (trf->state) {
858 	case TRF7970A_ST_IDLE:
859 	case TRF7970A_ST_IDLE_RX_BLOCKED:
860 		/* If initiator and getting interrupts caused by RF noise,
861 		 * turn off the receiver to avoid unnecessary interrupts.
862 		 * It will be turned back on in trf7970a_send_cmd() when
863 		 * the next command is issued.
864 		 */
865 		if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
866 			trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
867 			trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
868 		}
869 
870 		trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
871 		break;
872 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
873 		if (status & TRF7970A_IRQ_STATUS_TX) {
874 			trf->ignore_timeout =
875 				!cancel_delayed_work(&trf->timeout_work);
876 			trf7970a_fill_fifo(trf);
877 		} else {
878 			trf7970a_send_err_upstream(trf, -EIO);
879 		}
880 		break;
881 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
882 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
883 		if (status & TRF7970A_IRQ_STATUS_SRX) {
884 			trf->ignore_timeout =
885 				!cancel_delayed_work(&trf->timeout_work);
886 			trf7970a_drain_fifo(trf, status);
887 		} else if (status & TRF7970A_IRQ_STATUS_FIFO) {
888 			ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
889 					&fifo_bytes);
890 
891 			fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
892 
893 			if (ret)
894 				trf7970a_send_err_upstream(trf, ret);
895 			else if (!fifo_bytes)
896 				trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
897 		} else if ((status == TRF7970A_IRQ_STATUS_TX) ||
898 				(!trf->is_initiator &&
899 				 (status == (TRF7970A_IRQ_STATUS_TX |
900 					     TRF7970A_IRQ_STATUS_NFC_RF)))) {
901 			trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
902 
903 			if (!trf->timeout) {
904 				trf->ignore_timeout = !cancel_delayed_work(
905 						&trf->timeout_work);
906 				trf->rx_skb = ERR_PTR(0);
907 				trf7970a_send_upstream(trf);
908 				break;
909 			}
910 
911 			if (trf->is_initiator)
912 				break;
913 
914 			iso_ctrl = trf->iso_ctrl;
915 
916 			switch (trf->framing) {
917 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
918 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
919 				iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
920 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
921 				break;
922 			case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
923 				trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
924 				iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
925 				trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
926 				break;
927 			case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
928 				ret = trf7970a_write(trf,
929 					TRF7970A_SPECIAL_FCN_REG1,
930 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
931 				if (ret)
932 					goto err_unlock_exit;
933 
934 				trf->special_fcn_reg1 =
935 					TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
936 				break;
937 			default:
938 				break;
939 			}
940 
941 			if (iso_ctrl != trf->iso_ctrl) {
942 				ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
943 						iso_ctrl);
944 				if (ret)
945 					goto err_unlock_exit;
946 
947 				trf->iso_ctrl = iso_ctrl;
948 			}
949 		} else {
950 			trf7970a_send_err_upstream(trf, -EIO);
951 		}
952 		break;
953 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
954 		if (status != TRF7970A_IRQ_STATUS_TX)
955 			trf7970a_send_err_upstream(trf, -EIO);
956 		break;
957 	case TRF7970A_ST_LISTENING:
958 		if (status & TRF7970A_IRQ_STATUS_SRX) {
959 			trf->ignore_timeout =
960 				!cancel_delayed_work(&trf->timeout_work);
961 			trf7970a_drain_fifo(trf, status);
962 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
963 			trf7970a_send_err_upstream(trf, -EIO);
964 		}
965 		break;
966 	case TRF7970A_ST_LISTENING_MD:
967 		if (status & TRF7970A_IRQ_STATUS_SRX) {
968 			trf->ignore_timeout =
969 				!cancel_delayed_work(&trf->timeout_work);
970 
971 			ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
972 			if (ret) {
973 				trf7970a_send_err_upstream(trf, ret);
974 			} else {
975 				trf->state = TRF7970A_ST_LISTENING;
976 				trf7970a_drain_fifo(trf, status);
977 			}
978 		} else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
979 			trf7970a_send_err_upstream(trf, -EIO);
980 		}
981 		break;
982 	default:
983 		dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
984 				__func__, trf->state);
985 	}
986 
987 err_unlock_exit:
988 	mutex_unlock(&trf->lock);
989 	return IRQ_HANDLED;
990 }
991 
992 static void trf7970a_issue_eof(struct trf7970a *trf)
993 {
994 	int ret;
995 
996 	dev_dbg(trf->dev, "Issuing EOF\n");
997 
998 	ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
999 	if (ret)
1000 		trf7970a_send_err_upstream(trf, ret);
1001 
1002 	ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1003 	if (ret)
1004 		trf7970a_send_err_upstream(trf, ret);
1005 
1006 	trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1007 
1008 	dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1009 			trf->timeout, trf->state);
1010 
1011 	schedule_delayed_work(&trf->timeout_work,
1012 			msecs_to_jiffies(trf->timeout));
1013 }
1014 
1015 static void trf7970a_timeout_work_handler(struct work_struct *work)
1016 {
1017 	struct trf7970a *trf = container_of(work, struct trf7970a,
1018 			timeout_work.work);
1019 
1020 	dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1021 			trf->state, trf->ignore_timeout);
1022 
1023 	mutex_lock(&trf->lock);
1024 
1025 	if (trf->ignore_timeout)
1026 		trf->ignore_timeout = false;
1027 	else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1028 		trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1029 	else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1030 		trf7970a_issue_eof(trf);
1031 	else
1032 		trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1033 
1034 	mutex_unlock(&trf->lock);
1035 }
1036 
1037 static int trf7970a_init(struct trf7970a *trf)
1038 {
1039 	int ret;
1040 
1041 	dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1042 
1043 	ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1044 	if (ret)
1045 		goto err_out;
1046 
1047 	ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1048 	if (ret)
1049 		goto err_out;
1050 
1051 	usleep_range(1000, 2000);
1052 
1053 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1054 
1055 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0);
1056 	if (ret)
1057 		goto err_out;
1058 
1059 	trf->modulator_sys_clk_ctrl = 0;
1060 
1061 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1062 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1063 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1064 	if (ret)
1065 		goto err_out;
1066 
1067 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1068 	if (ret)
1069 		goto err_out;
1070 
1071 	trf->special_fcn_reg1 = 0;
1072 
1073 	trf->iso_ctrl = 0xff;
1074 	return 0;
1075 
1076 err_out:
1077 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1078 	return ret;
1079 }
1080 
1081 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1082 {
1083 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1084 			(trf->state == TRF7970A_ST_RF_OFF))
1085 		return;
1086 
1087 	dev_dbg(trf->dev, "Switching rf off\n");
1088 
1089 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1090 
1091 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1092 
1093 	trf->aborting = false;
1094 	trf->state = TRF7970A_ST_RF_OFF;
1095 
1096 	pm_runtime_mark_last_busy(trf->dev);
1097 	pm_runtime_put_autosuspend(trf->dev);
1098 }
1099 
1100 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1101 {
1102 	int ret;
1103 
1104 	dev_dbg(trf->dev, "Switching rf on\n");
1105 
1106 	pm_runtime_get_sync(trf->dev);
1107 
1108 	if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1109 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1110 				trf->state);
1111 		return -EINVAL;
1112 	}
1113 
1114 	ret = trf7970a_init(trf);
1115 	if (ret) {
1116 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1117 		return ret;
1118 	}
1119 
1120 	trf->state = TRF7970A_ST_IDLE;
1121 
1122 	return 0;
1123 }
1124 
1125 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1126 {
1127 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1128 	int ret = 0;
1129 
1130 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1131 
1132 	mutex_lock(&trf->lock);
1133 
1134 	if (on) {
1135 		switch (trf->state) {
1136 		case TRF7970A_ST_PWR_OFF:
1137 		case TRF7970A_ST_RF_OFF:
1138 			ret = trf7970a_switch_rf_on(trf);
1139 			break;
1140 		case TRF7970A_ST_IDLE:
1141 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1142 			break;
1143 		default:
1144 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1145 					__func__, trf->state, on);
1146 			trf7970a_switch_rf_off(trf);
1147 			ret = -EINVAL;
1148 		}
1149 	} else {
1150 		switch (trf->state) {
1151 		case TRF7970A_ST_PWR_OFF:
1152 		case TRF7970A_ST_RF_OFF:
1153 			break;
1154 		default:
1155 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1156 					__func__, trf->state, on);
1157 			ret = -EINVAL;
1158 			/* FALLTHROUGH */
1159 		case TRF7970A_ST_IDLE:
1160 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1161 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1162 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1163 			trf7970a_switch_rf_off(trf);
1164 		}
1165 	}
1166 
1167 	mutex_unlock(&trf->lock);
1168 	return ret;
1169 }
1170 
1171 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1172 {
1173 	int ret = 0;
1174 
1175 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1176 
1177 	switch (tech) {
1178 	case NFC_DIGITAL_RF_TECH_106A:
1179 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1180 		trf->modulator_sys_clk_ctrl = 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 = TRF7970A_MODULATOR_DEPTH_ASK10;
1186 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1187 		break;
1188 	case NFC_DIGITAL_RF_TECH_212F:
1189 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1190 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1191 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1192 		break;
1193 	case NFC_DIGITAL_RF_TECH_424F:
1194 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1195 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1196 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1197 		break;
1198 	case NFC_DIGITAL_RF_TECH_ISO15693:
1199 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1200 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
1201 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1202 		break;
1203 	default:
1204 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1205 		return -EINVAL;
1206 	}
1207 
1208 	trf->technology = tech;
1209 
1210 	/* If in initiator mode and not changing the RF tech due to a
1211 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1212 	 * trf7970a_init()), clear the NFC Target Detection Level register
1213 	 * due to erratum.
1214 	 */
1215 	if (trf->iso_ctrl == 0xff)
1216 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1217 
1218 	return ret;
1219 }
1220 
1221 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1222 {
1223 	int ret;
1224 	u8 rssi;
1225 
1226 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1227 			trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
1228 	if (ret)
1229 		return ret;
1230 
1231 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1232 	if (ret)
1233 		return ret;
1234 
1235 	usleep_range(50, 60);
1236 
1237 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1238 	if (ret)
1239 		return ret;
1240 
1241 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1242 			trf->chip_status_ctrl);
1243 	if (ret)
1244 		return ret;
1245 
1246 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1247 		*is_rf_field = true;
1248 	else
1249 		*is_rf_field = false;
1250 
1251 	return 0;
1252 }
1253 
1254 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1255 {
1256 	u8 iso_ctrl = trf->iso_ctrl_tech;
1257 	bool is_rf_field = false;
1258 	int ret;
1259 
1260 	dev_dbg(trf->dev, "framing: %d\n", framing);
1261 
1262 	switch (framing) {
1263 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1264 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1265 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1266 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1267 		break;
1268 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1269 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1270 	case NFC_DIGITAL_FRAMING_NFCB:
1271 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1272 	case NFC_DIGITAL_FRAMING_NFCF:
1273 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1274 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1275 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1276 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1277 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1278 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1279 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1280 		break;
1281 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1282 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1283 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1284 		break;
1285 	default:
1286 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1287 		return -EINVAL;
1288 	}
1289 
1290 	trf->framing = framing;
1291 
1292 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1293 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1294 		if (ret)
1295 			return ret;
1296 
1297 		if (is_rf_field)
1298 			return -EBUSY;
1299 	}
1300 
1301 	if (iso_ctrl != trf->iso_ctrl) {
1302 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1303 		if (ret)
1304 			return ret;
1305 
1306 		trf->iso_ctrl = iso_ctrl;
1307 
1308 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1309 				trf->modulator_sys_clk_ctrl);
1310 		if (ret)
1311 			return ret;
1312 	}
1313 
1314 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1315 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1316 				trf->chip_status_ctrl |
1317 					TRF7970A_CHIP_STATUS_RF_ON);
1318 		if (ret)
1319 			return ret;
1320 
1321 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1322 
1323 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1324 	}
1325 
1326 	return 0;
1327 }
1328 
1329 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1330 		int param)
1331 {
1332 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1333 	int ret;
1334 
1335 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1336 
1337 	mutex_lock(&trf->lock);
1338 
1339 	trf->is_initiator = true;
1340 
1341 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1342 			(trf->state == TRF7970A_ST_RF_OFF)) {
1343 		ret = trf7970a_switch_rf_on(trf);
1344 		if (ret)
1345 			goto err_unlock;
1346 	}
1347 
1348 	switch (type) {
1349 	case NFC_DIGITAL_CONFIG_RF_TECH:
1350 		ret = trf7970a_in_config_rf_tech(trf, param);
1351 		break;
1352 	case NFC_DIGITAL_CONFIG_FRAMING:
1353 		ret = trf7970a_in_config_framing(trf, param);
1354 		break;
1355 	default:
1356 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1357 		ret = -EINVAL;
1358 	}
1359 
1360 err_unlock:
1361 	mutex_unlock(&trf->lock);
1362 	return ret;
1363 }
1364 
1365 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1366 {
1367 	switch (cmd) {
1368 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1369 	case ISO15693_CMD_LOCK_BLOCK:
1370 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1371 	case ISO15693_CMD_WRITE_AFI:
1372 	case ISO15693_CMD_LOCK_AFI:
1373 	case ISO15693_CMD_WRITE_DSFID:
1374 	case ISO15693_CMD_LOCK_DSFID:
1375 		return 1;
1376 		break;
1377 	default:
1378 		return 0;
1379 	}
1380 }
1381 
1382 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1383 {
1384 	u8 *req = skb->data;
1385 	u8 special_fcn_reg1, iso_ctrl;
1386 	int ret;
1387 
1388 	trf->issue_eof = false;
1389 
1390 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1391 	 * special functions register 1 is cleared; otherwise, its a write or
1392 	 * sector select command and '4_bit_RX' must be set.
1393 	 *
1394 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1395 	 * what speed to use.  Also, remember if the OPTION flag is set on
1396 	 * a Type 5 write or lock command so the driver will know that it
1397 	 * has to send an EOF in order to get a response.
1398 	 */
1399 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1400 			(trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1401 		if (req[0] == NFC_T2T_CMD_READ)
1402 			special_fcn_reg1 = 0;
1403 		else
1404 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1405 
1406 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1407 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1408 					special_fcn_reg1);
1409 			if (ret)
1410 				return ret;
1411 
1412 			trf->special_fcn_reg1 = special_fcn_reg1;
1413 		}
1414 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1415 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1416 
1417 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1418 		case 0x00:
1419 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1420 			break;
1421 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1422 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1423 			break;
1424 		case ISO15693_REQ_FLAG_DATA_RATE:
1425 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1426 			break;
1427 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1428 				ISO15693_REQ_FLAG_DATA_RATE):
1429 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1430 			break;
1431 		}
1432 
1433 		if (iso_ctrl != trf->iso_ctrl) {
1434 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1435 			if (ret)
1436 				return ret;
1437 
1438 			trf->iso_ctrl = iso_ctrl;
1439 		}
1440 
1441 		if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
1442 			if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
1443 					(req[0] & ISO15693_REQ_FLAG_OPTION))
1444 				trf->issue_eof = true;
1445 			else if ((trf->quirks &
1446 					TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
1447 				 (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
1448 				trf->adjust_resp_len = true;
1449 		}
1450 	}
1451 
1452 	return 0;
1453 }
1454 
1455 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1456 		struct sk_buff *skb, u16 timeout,
1457 		nfc_digital_cmd_complete_t cb, void *arg)
1458 {
1459 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1460 	u8 prefix[5];
1461 	unsigned int len;
1462 	int ret;
1463 	u8 status;
1464 
1465 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1466 			trf->state, timeout, skb->len);
1467 
1468 	if (skb->len > TRF7970A_TX_MAX)
1469 		return -EINVAL;
1470 
1471 	mutex_lock(&trf->lock);
1472 
1473 	if ((trf->state != TRF7970A_ST_IDLE) &&
1474 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1475 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1476 				trf->state);
1477 		ret = -EIO;
1478 		goto out_err;
1479 	}
1480 
1481 	if (trf->aborting) {
1482 		dev_dbg(trf->dev, "Abort process complete\n");
1483 		trf->aborting = false;
1484 		ret = -ECANCELED;
1485 		goto out_err;
1486 	}
1487 
1488 	if (timeout) {
1489 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1490 				GFP_KERNEL);
1491 		if (!trf->rx_skb) {
1492 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1493 			ret = -ENOMEM;
1494 			goto out_err;
1495 		}
1496 	}
1497 
1498 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1499 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1500 		if (ret)
1501 			goto out_err;
1502 
1503 		trf->state = TRF7970A_ST_IDLE;
1504 	}
1505 
1506 	if (trf->is_initiator) {
1507 		ret = trf7970a_per_cmd_config(trf, skb);
1508 		if (ret)
1509 			goto out_err;
1510 	}
1511 
1512 	trf->ddev = ddev;
1513 	trf->tx_skb = skb;
1514 	trf->cb = cb;
1515 	trf->cb_arg = arg;
1516 	trf->timeout = timeout;
1517 	trf->ignore_timeout = false;
1518 
1519 	len = skb->len;
1520 
1521 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1522 	 * on what the current framing is, the address of the TX length byte 1
1523 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1524 	 * That totals 5 bytes.
1525 	 */
1526 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1527 			TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1528 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1529 			TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1530 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1531 
1532 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1533 		prefix[3] = 0x00;
1534 		prefix[4] = 0x0f; /* 7 bits */
1535 	} else {
1536 		prefix[3] = (len & 0xf00) >> 4;
1537 		prefix[3] |= ((len & 0xf0) >> 4);
1538 		prefix[4] = ((len & 0x0f) << 4);
1539 	}
1540 
1541 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1542 
1543 	/* Clear possible spurious interrupt */
1544 	ret = trf7970a_read_irqstatus(trf, &status);
1545 	if (ret)
1546 		goto out_err;
1547 
1548 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1549 	if (ret) {
1550 		kfree_skb(trf->rx_skb);
1551 		trf->rx_skb = NULL;
1552 	}
1553 
1554 out_err:
1555 	mutex_unlock(&trf->lock);
1556 	return ret;
1557 }
1558 
1559 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1560 {
1561 	int ret = 0;
1562 
1563 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1564 
1565 	switch (tech) {
1566 	case NFC_DIGITAL_RF_TECH_106A:
1567 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1568 			TRF7970A_ISO_CTRL_NFC_CE |
1569 			TRF7970A_ISO_CTRL_NFC_CE_14443A;
1570 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
1571 		break;
1572 	case NFC_DIGITAL_RF_TECH_212F:
1573 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1574 			TRF7970A_ISO_CTRL_NFC_NFCF_212;
1575 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1576 		break;
1577 	case NFC_DIGITAL_RF_TECH_424F:
1578 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1579 			TRF7970A_ISO_CTRL_NFC_NFCF_424;
1580 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1581 		break;
1582 	default:
1583 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1584 		return -EINVAL;
1585 	}
1586 
1587 	trf->technology = tech;
1588 
1589 	/* Normally we write the ISO_CTRL register in
1590 	 * trf7970a_tg_config_framing() because the framing can change
1591 	 * the value written.  However, when sending a PSL RES,
1592 	 * digital_tg_send_psl_res_complete() doesn't call
1593 	 * trf7970a_tg_config_framing() so we must write the register
1594 	 * here.
1595 	 */
1596 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1597 			(trf->iso_ctrl_tech != trf->iso_ctrl)) {
1598 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1599 				trf->iso_ctrl_tech);
1600 
1601 		trf->iso_ctrl = trf->iso_ctrl_tech;
1602 	}
1603 
1604 	return ret;
1605 }
1606 
1607 /* Since this is a target routine, several of the framing calls are
1608  * made between receiving the request and sending the response so they
1609  * should take effect until after the response is sent.  This is accomplished
1610  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1611  * handler.
1612  */
1613 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1614 {
1615 	u8 iso_ctrl = trf->iso_ctrl_tech;
1616 	int ret;
1617 
1618 	dev_dbg(trf->dev, "framing: %d\n", framing);
1619 
1620 	switch (framing) {
1621 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1622 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1623 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1624 		break;
1625 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1626 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1627 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1628 		/* These ones are applied in the interrupt handler */
1629 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1630 		break;
1631 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1632 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1633 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1634 		break;
1635 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1636 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1637 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1638 		break;
1639 	default:
1640 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1641 		return -EINVAL;
1642 	}
1643 
1644 	trf->framing = framing;
1645 
1646 	if (iso_ctrl != trf->iso_ctrl) {
1647 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1648 		if (ret)
1649 			return ret;
1650 
1651 		trf->iso_ctrl = iso_ctrl;
1652 
1653 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1654 				trf->modulator_sys_clk_ctrl);
1655 		if (ret)
1656 			return ret;
1657 	}
1658 
1659 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1660 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1661 				trf->chip_status_ctrl |
1662 					TRF7970A_CHIP_STATUS_RF_ON);
1663 		if (ret)
1664 			return ret;
1665 
1666 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1667 	}
1668 
1669 	return 0;
1670 }
1671 
1672 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1673 		int param)
1674 {
1675 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1676 	int ret;
1677 
1678 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1679 
1680 	mutex_lock(&trf->lock);
1681 
1682 	trf->is_initiator = false;
1683 
1684 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1685 			(trf->state == TRF7970A_ST_RF_OFF)) {
1686 		ret = trf7970a_switch_rf_on(trf);
1687 		if (ret)
1688 			goto err_unlock;
1689 	}
1690 
1691 	switch (type) {
1692 	case NFC_DIGITAL_CONFIG_RF_TECH:
1693 		ret = trf7970a_tg_config_rf_tech(trf, param);
1694 		break;
1695 	case NFC_DIGITAL_CONFIG_FRAMING:
1696 		ret = trf7970a_tg_config_framing(trf, param);
1697 		break;
1698 	default:
1699 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1700 		ret = -EINVAL;
1701 	}
1702 
1703 err_unlock:
1704 	mutex_unlock(&trf->lock);
1705 	return ret;
1706 }
1707 
1708 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1709 		nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
1710 {
1711 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1712 	int ret;
1713 
1714 	mutex_lock(&trf->lock);
1715 
1716 	if ((trf->state != TRF7970A_ST_IDLE) &&
1717 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1718 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1719 				trf->state);
1720 		ret = -EIO;
1721 		goto out_err;
1722 	}
1723 
1724 	if (trf->aborting) {
1725 		dev_dbg(trf->dev, "Abort process complete\n");
1726 		trf->aborting = false;
1727 		ret = -ECANCELED;
1728 		goto out_err;
1729 	}
1730 
1731 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1732 			GFP_KERNEL);
1733 	if (!trf->rx_skb) {
1734 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1735 		ret = -ENOMEM;
1736 		goto out_err;
1737 	}
1738 
1739 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1740 			TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1741 			TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1742 			TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1743 			TRF7970A_RX_SPECIAL_SETTINGS_C212);
1744 	if (ret)
1745 		goto out_err;
1746 
1747 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1748 			TRF7970A_REG_IO_CTRL_VRS(0x1));
1749 	if (ret)
1750 		goto out_err;
1751 
1752 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1753 			TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1754 	if (ret)
1755 		goto out_err;
1756 
1757 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1758 			TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1759 	if (ret)
1760 		goto out_err;
1761 
1762 	trf->ddev = ddev;
1763 	trf->cb = cb;
1764 	trf->cb_arg = arg;
1765 	trf->timeout = timeout;
1766 	trf->ignore_timeout = false;
1767 
1768 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1769 	if (ret)
1770 		goto out_err;
1771 
1772 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1773 				   TRF7970A_ST_LISTENING;
1774 
1775 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1776 
1777 out_err:
1778 	mutex_unlock(&trf->lock);
1779 	return ret;
1780 }
1781 
1782 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1783 		nfc_digital_cmd_complete_t cb, void *arg)
1784 {
1785 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1786 
1787 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1788 			trf->state, timeout);
1789 
1790 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1791 }
1792 
1793 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1794 		u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1795 {
1796 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1797 	int ret;
1798 
1799 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1800 			trf->state, timeout);
1801 
1802 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1803 			NFC_DIGITAL_RF_TECH_106A);
1804 	if (ret)
1805 		return ret;
1806 
1807 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1808 			NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1809 	if (ret)
1810 		return ret;
1811 
1812 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1813 }
1814 
1815 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1816 {
1817 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1818 
1819 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1820 			trf->state, trf->md_rf_tech);
1821 
1822 	*rf_tech = trf->md_rf_tech;
1823 
1824 	return 0;
1825 }
1826 
1827 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1828 {
1829 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1830 
1831 	dev_dbg(trf->dev, "Abort process initiated\n");
1832 
1833 	mutex_lock(&trf->lock);
1834 
1835 	switch (trf->state) {
1836 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1837 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1838 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1839 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1840 		trf->aborting = true;
1841 		break;
1842 	case TRF7970A_ST_LISTENING:
1843 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1844 		trf7970a_send_err_upstream(trf, -ECANCELED);
1845 		dev_dbg(trf->dev, "Abort process complete\n");
1846 		break;
1847 	default:
1848 		break;
1849 	}
1850 
1851 	mutex_unlock(&trf->lock);
1852 }
1853 
1854 static struct nfc_digital_ops trf7970a_nfc_ops = {
1855 	.in_configure_hw	= trf7970a_in_configure_hw,
1856 	.in_send_cmd		= trf7970a_send_cmd,
1857 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1858 	.tg_send_cmd		= trf7970a_send_cmd,
1859 	.tg_listen		= trf7970a_tg_listen,
1860 	.tg_listen_md		= trf7970a_tg_listen_md,
1861 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1862 	.switch_rf		= trf7970a_switch_rf,
1863 	.abort_cmd		= trf7970a_abort_cmd,
1864 };
1865 
1866 static int trf7970a_power_up(struct trf7970a *trf)
1867 {
1868 	int ret;
1869 
1870 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1871 
1872 	if (trf->state != TRF7970A_ST_PWR_OFF)
1873 		return 0;
1874 
1875 	ret = regulator_enable(trf->regulator);
1876 	if (ret) {
1877 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1878 		return ret;
1879 	}
1880 
1881 	usleep_range(5000, 6000);
1882 
1883 	if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1884 		gpio_set_value(trf->en2_gpio, 1);
1885 		usleep_range(1000, 2000);
1886 	}
1887 
1888 	gpio_set_value(trf->en_gpio, 1);
1889 
1890 	usleep_range(20000, 21000);
1891 
1892 	trf->state = TRF7970A_ST_RF_OFF;
1893 
1894 	return 0;
1895 }
1896 
1897 static int trf7970a_power_down(struct trf7970a *trf)
1898 {
1899 	int ret;
1900 
1901 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1902 
1903 	if (trf->state == TRF7970A_ST_PWR_OFF)
1904 		return 0;
1905 
1906 	if (trf->state != TRF7970A_ST_RF_OFF) {
1907 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1908 				trf->state);
1909 		return -EBUSY;
1910 	}
1911 
1912 	gpio_set_value(trf->en_gpio, 0);
1913 	gpio_set_value(trf->en2_gpio, 0);
1914 
1915 	ret = regulator_disable(trf->regulator);
1916 	if (ret)
1917 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1918 				ret);
1919 
1920 	trf->state = TRF7970A_ST_PWR_OFF;
1921 
1922 	return ret;
1923 }
1924 
1925 static int trf7970a_startup(struct trf7970a *trf)
1926 {
1927 	int ret;
1928 
1929 	ret = trf7970a_power_up(trf);
1930 	if (ret)
1931 		return ret;
1932 
1933 	pm_runtime_set_active(trf->dev);
1934 	pm_runtime_enable(trf->dev);
1935 	pm_runtime_mark_last_busy(trf->dev);
1936 
1937 	return 0;
1938 }
1939 
1940 static void trf7970a_shutdown(struct trf7970a *trf)
1941 {
1942 	switch (trf->state) {
1943 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1944 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1945 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1946 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1947 	case TRF7970A_ST_LISTENING:
1948 		trf7970a_send_err_upstream(trf, -ECANCELED);
1949 		/* FALLTHROUGH */
1950 	case TRF7970A_ST_IDLE:
1951 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1952 		trf7970a_switch_rf_off(trf);
1953 		break;
1954 	default:
1955 		break;
1956 	}
1957 
1958 	pm_runtime_disable(trf->dev);
1959 	pm_runtime_set_suspended(trf->dev);
1960 
1961 	trf7970a_power_down(trf);
1962 }
1963 
1964 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1965 {
1966 	int autosuspend_delay, ret;
1967 
1968 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1969 	if (ret)
1970 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1971 
1972 	return autosuspend_delay;
1973 }
1974 
1975 static int trf7970a_get_vin_voltage_override(struct device_node *np,
1976 		u32 *vin_uvolts)
1977 {
1978 	return of_property_read_u32(np, "vin-voltage-override", vin_uvolts);
1979 }
1980 
1981 static int trf7970a_probe(struct spi_device *spi)
1982 {
1983 	struct device_node *np = spi->dev.of_node;
1984 	struct trf7970a *trf;
1985 	int uvolts, autosuspend_delay, ret;
1986 
1987 	if (!np) {
1988 		dev_err(&spi->dev, "No Device Tree entry\n");
1989 		return -EINVAL;
1990 	}
1991 
1992 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
1993 	if (!trf)
1994 		return -ENOMEM;
1995 
1996 	trf->state = TRF7970A_ST_PWR_OFF;
1997 	trf->dev = &spi->dev;
1998 	trf->spi = spi;
1999 
2000 	spi->mode = SPI_MODE_1;
2001 	spi->bits_per_word = 8;
2002 
2003 	ret = spi_setup(spi);
2004 	if (ret < 0) {
2005 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2006 		return ret;
2007 	}
2008 
2009 	if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
2010 		trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
2011 
2012 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2013 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2014 
2015 	/* There are two enable pins - both must be present */
2016 	trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
2017 	if (!gpio_is_valid(trf->en_gpio)) {
2018 		dev_err(trf->dev, "No EN GPIO property\n");
2019 		return trf->en_gpio;
2020 	}
2021 
2022 	ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
2023 			GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN");
2024 	if (ret) {
2025 		dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
2026 		return ret;
2027 	}
2028 
2029 	trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
2030 	if (!gpio_is_valid(trf->en2_gpio)) {
2031 		dev_err(trf->dev, "No EN2 GPIO property\n");
2032 		return trf->en2_gpio;
2033 	}
2034 
2035 	ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
2036 			GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
2037 	if (ret) {
2038 		dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
2039 		return ret;
2040 	}
2041 
2042 	if (of_property_read_bool(np, "en2-rf-quirk"))
2043 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2044 
2045 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2046 			trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2047 			"trf7970a", trf);
2048 	if (ret) {
2049 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2050 		return ret;
2051 	}
2052 
2053 	mutex_init(&trf->lock);
2054 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2055 
2056 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2057 	if (IS_ERR(trf->regulator)) {
2058 		ret = PTR_ERR(trf->regulator);
2059 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2060 		goto err_destroy_lock;
2061 	}
2062 
2063 	ret = regulator_enable(trf->regulator);
2064 	if (ret) {
2065 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2066 		goto err_destroy_lock;
2067 	}
2068 
2069 	ret = trf7970a_get_vin_voltage_override(np, &uvolts);
2070 	if (ret)
2071 		uvolts = regulator_get_voltage(trf->regulator);
2072 
2073 	if (uvolts > 4000000)
2074 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2075 
2076 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2077 			TRF7970A_SUPPORTED_PROTOCOLS,
2078 			NFC_DIGITAL_DRV_CAPS_IN_CRC |
2079 				NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
2080 	if (!trf->ddev) {
2081 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2082 		ret = -ENOMEM;
2083 		goto err_disable_regulator;
2084 	}
2085 
2086 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2087 	nfc_digital_set_drvdata(trf->ddev, trf);
2088 	spi_set_drvdata(spi, trf);
2089 
2090 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2091 
2092 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2093 	pm_runtime_use_autosuspend(trf->dev);
2094 
2095 	ret = trf7970a_startup(trf);
2096 	if (ret)
2097 		goto err_free_ddev;
2098 
2099 	ret = nfc_digital_register_device(trf->ddev);
2100 	if (ret) {
2101 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2102 				ret);
2103 		goto err_shutdown;
2104 	}
2105 
2106 	return 0;
2107 
2108 err_shutdown:
2109 	trf7970a_shutdown(trf);
2110 err_free_ddev:
2111 	nfc_digital_free_device(trf->ddev);
2112 err_disable_regulator:
2113 	regulator_disable(trf->regulator);
2114 err_destroy_lock:
2115 	mutex_destroy(&trf->lock);
2116 	return ret;
2117 }
2118 
2119 static int trf7970a_remove(struct spi_device *spi)
2120 {
2121 	struct trf7970a *trf = spi_get_drvdata(spi);
2122 
2123 	mutex_lock(&trf->lock);
2124 
2125 	trf7970a_shutdown(trf);
2126 
2127 	mutex_unlock(&trf->lock);
2128 
2129 	nfc_digital_unregister_device(trf->ddev);
2130 	nfc_digital_free_device(trf->ddev);
2131 
2132 	regulator_disable(trf->regulator);
2133 
2134 	mutex_destroy(&trf->lock);
2135 
2136 	return 0;
2137 }
2138 
2139 #ifdef CONFIG_PM_SLEEP
2140 static int trf7970a_suspend(struct device *dev)
2141 {
2142 	struct spi_device *spi = container_of(dev, struct spi_device, dev);
2143 	struct trf7970a *trf = spi_get_drvdata(spi);
2144 
2145 	dev_dbg(dev, "Suspend\n");
2146 
2147 	mutex_lock(&trf->lock);
2148 
2149 	trf7970a_shutdown(trf);
2150 
2151 	mutex_unlock(&trf->lock);
2152 
2153 	return 0;
2154 }
2155 
2156 static int trf7970a_resume(struct device *dev)
2157 {
2158 	struct spi_device *spi = container_of(dev, struct spi_device, dev);
2159 	struct trf7970a *trf = spi_get_drvdata(spi);
2160 	int ret;
2161 
2162 	dev_dbg(dev, "Resume\n");
2163 
2164 	mutex_lock(&trf->lock);
2165 
2166 	ret = trf7970a_startup(trf);
2167 
2168 	mutex_unlock(&trf->lock);
2169 
2170 	return ret;
2171 }
2172 #endif
2173 
2174 #ifdef CONFIG_PM
2175 static int trf7970a_pm_runtime_suspend(struct device *dev)
2176 {
2177 	struct spi_device *spi = container_of(dev, struct spi_device, dev);
2178 	struct trf7970a *trf = spi_get_drvdata(spi);
2179 	int ret;
2180 
2181 	dev_dbg(dev, "Runtime suspend\n");
2182 
2183 	mutex_lock(&trf->lock);
2184 
2185 	ret = trf7970a_power_down(trf);
2186 
2187 	mutex_unlock(&trf->lock);
2188 
2189 	return ret;
2190 }
2191 
2192 static int trf7970a_pm_runtime_resume(struct device *dev)
2193 {
2194 	struct spi_device *spi = container_of(dev, struct spi_device, dev);
2195 	struct trf7970a *trf = spi_get_drvdata(spi);
2196 	int ret;
2197 
2198 	dev_dbg(dev, "Runtime resume\n");
2199 
2200 	ret = trf7970a_power_up(trf);
2201 	if (!ret)
2202 		pm_runtime_mark_last_busy(dev);
2203 
2204 	return ret;
2205 }
2206 #endif
2207 
2208 static const struct dev_pm_ops trf7970a_pm_ops = {
2209 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2210 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2211 			trf7970a_pm_runtime_resume, NULL)
2212 };
2213 
2214 static const struct of_device_id trf7970a_of_match[] = {
2215 	{ .compatible = "ti,trf7970a", },
2216 	{ /* sentinel */ },
2217 };
2218 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2219 
2220 static const struct spi_device_id trf7970a_id_table[] = {
2221 	{ "trf7970a", 0 },
2222 	{ }
2223 };
2224 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2225 
2226 static struct spi_driver trf7970a_spi_driver = {
2227 	.probe		= trf7970a_probe,
2228 	.remove		= trf7970a_remove,
2229 	.id_table	= trf7970a_id_table,
2230 	.driver		= {
2231 		.name	= "trf7970a",
2232 		.of_match_table = of_match_ptr(trf7970a_of_match),
2233 		.pm	= &trf7970a_pm_ops,
2234 	},
2235 };
2236 
2237 module_spi_driver(trf7970a_spi_driver);
2238 
2239 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2240 MODULE_LICENSE("GPL v2");
2241 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2242