xref: /openbmc/linux/drivers/nfc/trf7970a.c (revision 80483c3a)
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 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1052 	if (ret)
1053 		goto err_out;
1054 
1055 	usleep_range(1000, 2000);
1056 
1057 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1058 
1059 	ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0);
1060 	if (ret)
1061 		goto err_out;
1062 
1063 	trf->modulator_sys_clk_ctrl = 0;
1064 
1065 	ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1066 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1067 			TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1068 	if (ret)
1069 		goto err_out;
1070 
1071 	ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1072 	if (ret)
1073 		goto err_out;
1074 
1075 	trf->special_fcn_reg1 = 0;
1076 
1077 	trf->iso_ctrl = 0xff;
1078 	return 0;
1079 
1080 err_out:
1081 	dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1082 	return ret;
1083 }
1084 
1085 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1086 {
1087 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1088 			(trf->state == TRF7970A_ST_RF_OFF))
1089 		return;
1090 
1091 	dev_dbg(trf->dev, "Switching rf off\n");
1092 
1093 	trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1094 
1095 	trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1096 
1097 	trf->aborting = false;
1098 	trf->state = TRF7970A_ST_RF_OFF;
1099 
1100 	pm_runtime_mark_last_busy(trf->dev);
1101 	pm_runtime_put_autosuspend(trf->dev);
1102 }
1103 
1104 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1105 {
1106 	int ret;
1107 
1108 	dev_dbg(trf->dev, "Switching rf on\n");
1109 
1110 	pm_runtime_get_sync(trf->dev);
1111 
1112 	if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1113 		dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1114 				trf->state);
1115 		return -EINVAL;
1116 	}
1117 
1118 	ret = trf7970a_init(trf);
1119 	if (ret) {
1120 		dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1121 		return ret;
1122 	}
1123 
1124 	trf->state = TRF7970A_ST_IDLE;
1125 
1126 	return 0;
1127 }
1128 
1129 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1130 {
1131 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1132 	int ret = 0;
1133 
1134 	dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1135 
1136 	mutex_lock(&trf->lock);
1137 
1138 	if (on) {
1139 		switch (trf->state) {
1140 		case TRF7970A_ST_PWR_OFF:
1141 		case TRF7970A_ST_RF_OFF:
1142 			ret = trf7970a_switch_rf_on(trf);
1143 			break;
1144 		case TRF7970A_ST_IDLE:
1145 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1146 			break;
1147 		default:
1148 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1149 					__func__, trf->state, on);
1150 			trf7970a_switch_rf_off(trf);
1151 			ret = -EINVAL;
1152 		}
1153 	} else {
1154 		switch (trf->state) {
1155 		case TRF7970A_ST_PWR_OFF:
1156 		case TRF7970A_ST_RF_OFF:
1157 			break;
1158 		default:
1159 			dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1160 					__func__, trf->state, on);
1161 			ret = -EINVAL;
1162 			/* FALLTHROUGH */
1163 		case TRF7970A_ST_IDLE:
1164 		case TRF7970A_ST_IDLE_RX_BLOCKED:
1165 		case TRF7970A_ST_WAIT_FOR_RX_DATA:
1166 		case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1167 			trf7970a_switch_rf_off(trf);
1168 		}
1169 	}
1170 
1171 	mutex_unlock(&trf->lock);
1172 	return ret;
1173 }
1174 
1175 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1176 {
1177 	int ret = 0;
1178 
1179 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1180 
1181 	switch (tech) {
1182 	case NFC_DIGITAL_RF_TECH_106A:
1183 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1184 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
1185 		trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1186 		break;
1187 	case NFC_DIGITAL_RF_TECH_106B:
1188 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1189 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1190 		trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1191 		break;
1192 	case NFC_DIGITAL_RF_TECH_212F:
1193 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1194 		trf->modulator_sys_clk_ctrl = 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 = TRF7970A_MODULATOR_DEPTH_ASK10;
1200 		trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1201 		break;
1202 	case NFC_DIGITAL_RF_TECH_ISO15693:
1203 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1204 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_OOK;
1205 		trf->guard_time = TRF7970A_GUARD_TIME_15693;
1206 		break;
1207 	default:
1208 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1209 		return -EINVAL;
1210 	}
1211 
1212 	trf->technology = tech;
1213 
1214 	/* If in initiator mode and not changing the RF tech due to a
1215 	 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1216 	 * trf7970a_init()), clear the NFC Target Detection Level register
1217 	 * due to erratum.
1218 	 */
1219 	if (trf->iso_ctrl == 0xff)
1220 		ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1221 
1222 	return ret;
1223 }
1224 
1225 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1226 {
1227 	int ret;
1228 	u8 rssi;
1229 
1230 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1231 			trf->chip_status_ctrl | TRF7970A_CHIP_STATUS_REC_ON);
1232 	if (ret)
1233 		return ret;
1234 
1235 	ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1236 	if (ret)
1237 		return ret;
1238 
1239 	usleep_range(50, 60);
1240 
1241 	ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1242 	if (ret)
1243 		return ret;
1244 
1245 	ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1246 			trf->chip_status_ctrl);
1247 	if (ret)
1248 		return ret;
1249 
1250 	if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1251 		*is_rf_field = true;
1252 	else
1253 		*is_rf_field = false;
1254 
1255 	return 0;
1256 }
1257 
1258 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1259 {
1260 	u8 iso_ctrl = trf->iso_ctrl_tech;
1261 	bool is_rf_field = false;
1262 	int ret;
1263 
1264 	dev_dbg(trf->dev, "framing: %d\n", framing);
1265 
1266 	switch (framing) {
1267 	case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1268 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1269 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1270 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1271 		break;
1272 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1273 	case NFC_DIGITAL_FRAMING_NFCA_T4T:
1274 	case NFC_DIGITAL_FRAMING_NFCB:
1275 	case NFC_DIGITAL_FRAMING_NFCB_T4T:
1276 	case NFC_DIGITAL_FRAMING_NFCF:
1277 	case NFC_DIGITAL_FRAMING_NFCF_T3T:
1278 	case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1279 	case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1280 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1281 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1282 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1283 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1284 		break;
1285 	case NFC_DIGITAL_FRAMING_NFCA_T2T:
1286 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1287 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1288 		break;
1289 	default:
1290 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1291 		return -EINVAL;
1292 	}
1293 
1294 	trf->framing = framing;
1295 
1296 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1297 		ret = trf7970a_is_rf_field(trf, &is_rf_field);
1298 		if (ret)
1299 			return ret;
1300 
1301 		if (is_rf_field)
1302 			return -EBUSY;
1303 	}
1304 
1305 	if (iso_ctrl != trf->iso_ctrl) {
1306 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1307 		if (ret)
1308 			return ret;
1309 
1310 		trf->iso_ctrl = iso_ctrl;
1311 
1312 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1313 				trf->modulator_sys_clk_ctrl);
1314 		if (ret)
1315 			return ret;
1316 	}
1317 
1318 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1319 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1320 				trf->chip_status_ctrl |
1321 					TRF7970A_CHIP_STATUS_RF_ON);
1322 		if (ret)
1323 			return ret;
1324 
1325 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1326 
1327 		usleep_range(trf->guard_time, trf->guard_time + 1000);
1328 	}
1329 
1330 	return 0;
1331 }
1332 
1333 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1334 		int param)
1335 {
1336 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1337 	int ret;
1338 
1339 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1340 
1341 	mutex_lock(&trf->lock);
1342 
1343 	trf->is_initiator = true;
1344 
1345 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1346 			(trf->state == TRF7970A_ST_RF_OFF)) {
1347 		ret = trf7970a_switch_rf_on(trf);
1348 		if (ret)
1349 			goto err_unlock;
1350 	}
1351 
1352 	switch (type) {
1353 	case NFC_DIGITAL_CONFIG_RF_TECH:
1354 		ret = trf7970a_in_config_rf_tech(trf, param);
1355 		break;
1356 	case NFC_DIGITAL_CONFIG_FRAMING:
1357 		ret = trf7970a_in_config_framing(trf, param);
1358 		break;
1359 	default:
1360 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1361 		ret = -EINVAL;
1362 	}
1363 
1364 err_unlock:
1365 	mutex_unlock(&trf->lock);
1366 	return ret;
1367 }
1368 
1369 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1370 {
1371 	switch (cmd) {
1372 	case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1373 	case ISO15693_CMD_LOCK_BLOCK:
1374 	case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1375 	case ISO15693_CMD_WRITE_AFI:
1376 	case ISO15693_CMD_LOCK_AFI:
1377 	case ISO15693_CMD_WRITE_DSFID:
1378 	case ISO15693_CMD_LOCK_DSFID:
1379 		return 1;
1380 		break;
1381 	default:
1382 		return 0;
1383 	}
1384 }
1385 
1386 static int trf7970a_per_cmd_config(struct trf7970a *trf, struct sk_buff *skb)
1387 {
1388 	u8 *req = skb->data;
1389 	u8 special_fcn_reg1, iso_ctrl;
1390 	int ret;
1391 
1392 	trf->issue_eof = false;
1393 
1394 	/* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1395 	 * special functions register 1 is cleared; otherwise, its a write or
1396 	 * sector select command and '4_bit_RX' must be set.
1397 	 *
1398 	 * When issuing an ISO 15693 command, inspect the flags byte to see
1399 	 * what speed to use.  Also, remember if the OPTION flag is set on
1400 	 * a Type 5 write or lock command so the driver will know that it
1401 	 * has to send an EOF in order to get a response.
1402 	 */
1403 	if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1404 			(trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1405 		if (req[0] == NFC_T2T_CMD_READ)
1406 			special_fcn_reg1 = 0;
1407 		else
1408 			special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1409 
1410 		if (special_fcn_reg1 != trf->special_fcn_reg1) {
1411 			ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1412 					special_fcn_reg1);
1413 			if (ret)
1414 				return ret;
1415 
1416 			trf->special_fcn_reg1 = special_fcn_reg1;
1417 		}
1418 	} else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1419 		iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1420 
1421 		switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1422 		case 0x00:
1423 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1424 			break;
1425 		case ISO15693_REQ_FLAG_SUB_CARRIER:
1426 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1427 			break;
1428 		case ISO15693_REQ_FLAG_DATA_RATE:
1429 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1430 			break;
1431 		case (ISO15693_REQ_FLAG_SUB_CARRIER |
1432 				ISO15693_REQ_FLAG_DATA_RATE):
1433 			iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1434 			break;
1435 		}
1436 
1437 		if (iso_ctrl != trf->iso_ctrl) {
1438 			ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1439 			if (ret)
1440 				return ret;
1441 
1442 			trf->iso_ctrl = iso_ctrl;
1443 		}
1444 
1445 		if (trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) {
1446 			if (trf7970a_is_iso15693_write_or_lock(req[1]) &&
1447 					(req[0] & ISO15693_REQ_FLAG_OPTION))
1448 				trf->issue_eof = true;
1449 			else if ((trf->quirks &
1450 					TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE) &&
1451 				 (req[1] == ISO15693_CMD_READ_MULTIPLE_BLOCK))
1452 				trf->adjust_resp_len = true;
1453 		}
1454 	}
1455 
1456 	return 0;
1457 }
1458 
1459 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1460 		struct sk_buff *skb, u16 timeout,
1461 		nfc_digital_cmd_complete_t cb, void *arg)
1462 {
1463 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1464 	u8 prefix[5];
1465 	unsigned int len;
1466 	int ret;
1467 	u8 status;
1468 
1469 	dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1470 			trf->state, timeout, skb->len);
1471 
1472 	if (skb->len > TRF7970A_TX_MAX)
1473 		return -EINVAL;
1474 
1475 	mutex_lock(&trf->lock);
1476 
1477 	if ((trf->state != TRF7970A_ST_IDLE) &&
1478 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1479 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1480 				trf->state);
1481 		ret = -EIO;
1482 		goto out_err;
1483 	}
1484 
1485 	if (trf->aborting) {
1486 		dev_dbg(trf->dev, "Abort process complete\n");
1487 		trf->aborting = false;
1488 		ret = -ECANCELED;
1489 		goto out_err;
1490 	}
1491 
1492 	if (timeout) {
1493 		trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1494 				GFP_KERNEL);
1495 		if (!trf->rx_skb) {
1496 			dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1497 			ret = -ENOMEM;
1498 			goto out_err;
1499 		}
1500 	}
1501 
1502 	if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1503 		ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1504 		if (ret)
1505 			goto out_err;
1506 
1507 		trf->state = TRF7970A_ST_IDLE;
1508 	}
1509 
1510 	if (trf->is_initiator) {
1511 		ret = trf7970a_per_cmd_config(trf, skb);
1512 		if (ret)
1513 			goto out_err;
1514 	}
1515 
1516 	trf->ddev = ddev;
1517 	trf->tx_skb = skb;
1518 	trf->cb = cb;
1519 	trf->cb_arg = arg;
1520 	trf->timeout = timeout;
1521 	trf->ignore_timeout = false;
1522 
1523 	len = skb->len;
1524 
1525 	/* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1526 	 * on what the current framing is, the address of the TX length byte 1
1527 	 * register (0x1d), and the 2 byte length of the data to be transmitted.
1528 	 * That totals 5 bytes.
1529 	 */
1530 	prefix[0] = TRF7970A_CMD_BIT_CTRL |
1531 			TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1532 	prefix[1] = TRF7970A_CMD_BIT_CTRL |
1533 			TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1534 	prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1535 
1536 	if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1537 		prefix[3] = 0x00;
1538 		prefix[4] = 0x0f; /* 7 bits */
1539 	} else {
1540 		prefix[3] = (len & 0xf00) >> 4;
1541 		prefix[3] |= ((len & 0xf0) >> 4);
1542 		prefix[4] = ((len & 0x0f) << 4);
1543 	}
1544 
1545 	len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1546 
1547 	/* Clear possible spurious interrupt */
1548 	ret = trf7970a_read_irqstatus(trf, &status);
1549 	if (ret)
1550 		goto out_err;
1551 
1552 	ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1553 	if (ret) {
1554 		kfree_skb(trf->rx_skb);
1555 		trf->rx_skb = NULL;
1556 	}
1557 
1558 out_err:
1559 	mutex_unlock(&trf->lock);
1560 	return ret;
1561 }
1562 
1563 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1564 {
1565 	int ret = 0;
1566 
1567 	dev_dbg(trf->dev, "rf technology: %d\n", tech);
1568 
1569 	switch (tech) {
1570 	case NFC_DIGITAL_RF_TECH_106A:
1571 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1572 			TRF7970A_ISO_CTRL_NFC_CE |
1573 			TRF7970A_ISO_CTRL_NFC_CE_14443A;
1574 		trf->modulator_sys_clk_ctrl = 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 = TRF7970A_MODULATOR_DEPTH_ASK10;
1580 		break;
1581 	case NFC_DIGITAL_RF_TECH_424F:
1582 		trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1583 			TRF7970A_ISO_CTRL_NFC_NFCF_424;
1584 		trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_DEPTH_ASK10;
1585 		break;
1586 	default:
1587 		dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1588 		return -EINVAL;
1589 	}
1590 
1591 	trf->technology = tech;
1592 
1593 	/* Normally we write the ISO_CTRL register in
1594 	 * trf7970a_tg_config_framing() because the framing can change
1595 	 * the value written.  However, when sending a PSL RES,
1596 	 * digital_tg_send_psl_res_complete() doesn't call
1597 	 * trf7970a_tg_config_framing() so we must write the register
1598 	 * here.
1599 	 */
1600 	if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1601 			(trf->iso_ctrl_tech != trf->iso_ctrl)) {
1602 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL,
1603 				trf->iso_ctrl_tech);
1604 
1605 		trf->iso_ctrl = trf->iso_ctrl_tech;
1606 	}
1607 
1608 	return ret;
1609 }
1610 
1611 /* Since this is a target routine, several of the framing calls are
1612  * made between receiving the request and sending the response so they
1613  * should take effect until after the response is sent.  This is accomplished
1614  * by skipping the ISO_CTRL register write here and doing it in the interrupt
1615  * handler.
1616  */
1617 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1618 {
1619 	u8 iso_ctrl = trf->iso_ctrl_tech;
1620 	int ret;
1621 
1622 	dev_dbg(trf->dev, "framing: %d\n", framing);
1623 
1624 	switch (framing) {
1625 	case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1626 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1627 		iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1628 		break;
1629 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1630 	case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1631 	case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1632 		/* These ones are applied in the interrupt handler */
1633 		iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1634 		break;
1635 	case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1636 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1637 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1638 		break;
1639 	case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1640 		trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1641 		iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1642 		break;
1643 	default:
1644 		dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1645 		return -EINVAL;
1646 	}
1647 
1648 	trf->framing = framing;
1649 
1650 	if (iso_ctrl != trf->iso_ctrl) {
1651 		ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
1652 		if (ret)
1653 			return ret;
1654 
1655 		trf->iso_ctrl = iso_ctrl;
1656 
1657 		ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1658 				trf->modulator_sys_clk_ctrl);
1659 		if (ret)
1660 			return ret;
1661 	}
1662 
1663 	if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1664 		ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1665 				trf->chip_status_ctrl |
1666 					TRF7970A_CHIP_STATUS_RF_ON);
1667 		if (ret)
1668 			return ret;
1669 
1670 		trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1671 	}
1672 
1673 	return 0;
1674 }
1675 
1676 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1677 		int param)
1678 {
1679 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1680 	int ret;
1681 
1682 	dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1683 
1684 	mutex_lock(&trf->lock);
1685 
1686 	trf->is_initiator = false;
1687 
1688 	if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1689 			(trf->state == TRF7970A_ST_RF_OFF)) {
1690 		ret = trf7970a_switch_rf_on(trf);
1691 		if (ret)
1692 			goto err_unlock;
1693 	}
1694 
1695 	switch (type) {
1696 	case NFC_DIGITAL_CONFIG_RF_TECH:
1697 		ret = trf7970a_tg_config_rf_tech(trf, param);
1698 		break;
1699 	case NFC_DIGITAL_CONFIG_FRAMING:
1700 		ret = trf7970a_tg_config_framing(trf, param);
1701 		break;
1702 	default:
1703 		dev_dbg(trf->dev, "Unknown type: %d\n", type);
1704 		ret = -EINVAL;
1705 	}
1706 
1707 err_unlock:
1708 	mutex_unlock(&trf->lock);
1709 	return ret;
1710 }
1711 
1712 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1713 		nfc_digital_cmd_complete_t cb, void *arg, bool mode_detect)
1714 {
1715 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1716 	int ret;
1717 
1718 	mutex_lock(&trf->lock);
1719 
1720 	if ((trf->state != TRF7970A_ST_IDLE) &&
1721 			(trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1722 		dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1723 				trf->state);
1724 		ret = -EIO;
1725 		goto out_err;
1726 	}
1727 
1728 	if (trf->aborting) {
1729 		dev_dbg(trf->dev, "Abort process complete\n");
1730 		trf->aborting = false;
1731 		ret = -ECANCELED;
1732 		goto out_err;
1733 	}
1734 
1735 	trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1736 			GFP_KERNEL);
1737 	if (!trf->rx_skb) {
1738 		dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1739 		ret = -ENOMEM;
1740 		goto out_err;
1741 	}
1742 
1743 	ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1744 			TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1745 			TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1746 			TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1747 			TRF7970A_RX_SPECIAL_SETTINGS_C212);
1748 	if (ret)
1749 		goto out_err;
1750 
1751 	ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1752 			TRF7970A_REG_IO_CTRL_VRS(0x1));
1753 	if (ret)
1754 		goto out_err;
1755 
1756 	ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1757 			TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1758 	if (ret)
1759 		goto out_err;
1760 
1761 	ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1762 			TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1763 	if (ret)
1764 		goto out_err;
1765 
1766 	trf->ddev = ddev;
1767 	trf->cb = cb;
1768 	trf->cb_arg = arg;
1769 	trf->timeout = timeout;
1770 	trf->ignore_timeout = false;
1771 
1772 	ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1773 	if (ret)
1774 		goto out_err;
1775 
1776 	trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1777 				   TRF7970A_ST_LISTENING;
1778 
1779 	schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1780 
1781 out_err:
1782 	mutex_unlock(&trf->lock);
1783 	return ret;
1784 }
1785 
1786 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1787 		nfc_digital_cmd_complete_t cb, void *arg)
1788 {
1789 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1790 
1791 	dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1792 			trf->state, timeout);
1793 
1794 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1795 }
1796 
1797 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1798 		u16 timeout, nfc_digital_cmd_complete_t cb, void *arg)
1799 {
1800 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1801 	int ret;
1802 
1803 	dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1804 			trf->state, timeout);
1805 
1806 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1807 			NFC_DIGITAL_RF_TECH_106A);
1808 	if (ret)
1809 		return ret;
1810 
1811 	ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1812 			NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1813 	if (ret)
1814 		return ret;
1815 
1816 	return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1817 }
1818 
1819 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1820 {
1821 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1822 
1823 	dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1824 			trf->state, trf->md_rf_tech);
1825 
1826 	*rf_tech = trf->md_rf_tech;
1827 
1828 	return 0;
1829 }
1830 
1831 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1832 {
1833 	struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1834 
1835 	dev_dbg(trf->dev, "Abort process initiated\n");
1836 
1837 	mutex_lock(&trf->lock);
1838 
1839 	switch (trf->state) {
1840 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1841 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1842 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1843 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1844 		trf->aborting = true;
1845 		break;
1846 	case TRF7970A_ST_LISTENING:
1847 		trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1848 		trf7970a_send_err_upstream(trf, -ECANCELED);
1849 		dev_dbg(trf->dev, "Abort process complete\n");
1850 		break;
1851 	default:
1852 		break;
1853 	}
1854 
1855 	mutex_unlock(&trf->lock);
1856 }
1857 
1858 static struct nfc_digital_ops trf7970a_nfc_ops = {
1859 	.in_configure_hw	= trf7970a_in_configure_hw,
1860 	.in_send_cmd		= trf7970a_send_cmd,
1861 	.tg_configure_hw	= trf7970a_tg_configure_hw,
1862 	.tg_send_cmd		= trf7970a_send_cmd,
1863 	.tg_listen		= trf7970a_tg_listen,
1864 	.tg_listen_md		= trf7970a_tg_listen_md,
1865 	.tg_get_rf_tech		= trf7970a_tg_get_rf_tech,
1866 	.switch_rf		= trf7970a_switch_rf,
1867 	.abort_cmd		= trf7970a_abort_cmd,
1868 };
1869 
1870 static int trf7970a_power_up(struct trf7970a *trf)
1871 {
1872 	int ret;
1873 
1874 	dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1875 
1876 	if (trf->state != TRF7970A_ST_PWR_OFF)
1877 		return 0;
1878 
1879 	ret = regulator_enable(trf->regulator);
1880 	if (ret) {
1881 		dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1882 		return ret;
1883 	}
1884 
1885 	usleep_range(5000, 6000);
1886 
1887 	if (!(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1888 		gpio_set_value(trf->en2_gpio, 1);
1889 		usleep_range(1000, 2000);
1890 	}
1891 
1892 	gpio_set_value(trf->en_gpio, 1);
1893 
1894 	usleep_range(20000, 21000);
1895 
1896 	trf->state = TRF7970A_ST_RF_OFF;
1897 
1898 	return 0;
1899 }
1900 
1901 static int trf7970a_power_down(struct trf7970a *trf)
1902 {
1903 	int ret;
1904 
1905 	dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1906 
1907 	if (trf->state == TRF7970A_ST_PWR_OFF)
1908 		return 0;
1909 
1910 	if (trf->state != TRF7970A_ST_RF_OFF) {
1911 		dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1912 				trf->state);
1913 		return -EBUSY;
1914 	}
1915 
1916 	gpio_set_value(trf->en_gpio, 0);
1917 	gpio_set_value(trf->en2_gpio, 0);
1918 
1919 	ret = regulator_disable(trf->regulator);
1920 	if (ret)
1921 		dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1922 				ret);
1923 
1924 	trf->state = TRF7970A_ST_PWR_OFF;
1925 
1926 	return ret;
1927 }
1928 
1929 static int trf7970a_startup(struct trf7970a *trf)
1930 {
1931 	int ret;
1932 
1933 	ret = trf7970a_power_up(trf);
1934 	if (ret)
1935 		return ret;
1936 
1937 	pm_runtime_set_active(trf->dev);
1938 	pm_runtime_enable(trf->dev);
1939 	pm_runtime_mark_last_busy(trf->dev);
1940 
1941 	return 0;
1942 }
1943 
1944 static void trf7970a_shutdown(struct trf7970a *trf)
1945 {
1946 	switch (trf->state) {
1947 	case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1948 	case TRF7970A_ST_WAIT_FOR_RX_DATA:
1949 	case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1950 	case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1951 	case TRF7970A_ST_LISTENING:
1952 		trf7970a_send_err_upstream(trf, -ECANCELED);
1953 		/* FALLTHROUGH */
1954 	case TRF7970A_ST_IDLE:
1955 	case TRF7970A_ST_IDLE_RX_BLOCKED:
1956 		trf7970a_switch_rf_off(trf);
1957 		break;
1958 	default:
1959 		break;
1960 	}
1961 
1962 	pm_runtime_disable(trf->dev);
1963 	pm_runtime_set_suspended(trf->dev);
1964 
1965 	trf7970a_power_down(trf);
1966 }
1967 
1968 static int trf7970a_get_autosuspend_delay(struct device_node *np)
1969 {
1970 	int autosuspend_delay, ret;
1971 
1972 	ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
1973 	if (ret)
1974 		autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
1975 
1976 	return autosuspend_delay;
1977 }
1978 
1979 static int trf7970a_get_vin_voltage_override(struct device_node *np,
1980 		u32 *vin_uvolts)
1981 {
1982 	return of_property_read_u32(np, "vin-voltage-override", vin_uvolts);
1983 }
1984 
1985 static int trf7970a_probe(struct spi_device *spi)
1986 {
1987 	struct device_node *np = spi->dev.of_node;
1988 	struct trf7970a *trf;
1989 	int uvolts, autosuspend_delay, ret;
1990 
1991 	if (!np) {
1992 		dev_err(&spi->dev, "No Device Tree entry\n");
1993 		return -EINVAL;
1994 	}
1995 
1996 	trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
1997 	if (!trf)
1998 		return -ENOMEM;
1999 
2000 	trf->state = TRF7970A_ST_PWR_OFF;
2001 	trf->dev = &spi->dev;
2002 	trf->spi = spi;
2003 
2004 	spi->mode = SPI_MODE_1;
2005 	spi->bits_per_word = 8;
2006 
2007 	ret = spi_setup(spi);
2008 	if (ret < 0) {
2009 		dev_err(trf->dev, "Can't set up SPI Communication\n");
2010 		return ret;
2011 	}
2012 
2013 	if (of_property_read_bool(np, "t5t-rmb-extra-byte-quirk"))
2014 		trf->quirks |= TRF7970A_QUIRK_T5T_RMB_EXTRA_BYTE;
2015 
2016 	if (of_property_read_bool(np, "irq-status-read-quirk"))
2017 		trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2018 
2019 	/* There are two enable pins - both must be present */
2020 	trf->en_gpio = of_get_named_gpio(np, "ti,enable-gpios", 0);
2021 	if (!gpio_is_valid(trf->en_gpio)) {
2022 		dev_err(trf->dev, "No EN GPIO property\n");
2023 		return trf->en_gpio;
2024 	}
2025 
2026 	ret = devm_gpio_request_one(trf->dev, trf->en_gpio,
2027 			GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN");
2028 	if (ret) {
2029 		dev_err(trf->dev, "Can't request EN GPIO: %d\n", ret);
2030 		return ret;
2031 	}
2032 
2033 	trf->en2_gpio = of_get_named_gpio(np, "ti,enable-gpios", 1);
2034 	if (!gpio_is_valid(trf->en2_gpio)) {
2035 		dev_err(trf->dev, "No EN2 GPIO property\n");
2036 		return trf->en2_gpio;
2037 	}
2038 
2039 	ret = devm_gpio_request_one(trf->dev, trf->en2_gpio,
2040 			GPIOF_DIR_OUT | GPIOF_INIT_LOW, "trf7970a EN2");
2041 	if (ret) {
2042 		dev_err(trf->dev, "Can't request EN2 GPIO: %d\n", ret);
2043 		return ret;
2044 	}
2045 
2046 	if (of_property_read_bool(np, "en2-rf-quirk"))
2047 		trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2048 
2049 	ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2050 			trf7970a_irq, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2051 			"trf7970a", trf);
2052 	if (ret) {
2053 		dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2054 		return ret;
2055 	}
2056 
2057 	mutex_init(&trf->lock);
2058 	INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2059 
2060 	trf->regulator = devm_regulator_get(&spi->dev, "vin");
2061 	if (IS_ERR(trf->regulator)) {
2062 		ret = PTR_ERR(trf->regulator);
2063 		dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2064 		goto err_destroy_lock;
2065 	}
2066 
2067 	ret = regulator_enable(trf->regulator);
2068 	if (ret) {
2069 		dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2070 		goto err_destroy_lock;
2071 	}
2072 
2073 	ret = trf7970a_get_vin_voltage_override(np, &uvolts);
2074 	if (ret)
2075 		uvolts = regulator_get_voltage(trf->regulator);
2076 
2077 	if (uvolts > 4000000)
2078 		trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2079 
2080 	trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2081 			TRF7970A_SUPPORTED_PROTOCOLS,
2082 			NFC_DIGITAL_DRV_CAPS_IN_CRC |
2083 				NFC_DIGITAL_DRV_CAPS_TG_CRC, 0, 0);
2084 	if (!trf->ddev) {
2085 		dev_err(trf->dev, "Can't allocate NFC digital device\n");
2086 		ret = -ENOMEM;
2087 		goto err_disable_regulator;
2088 	}
2089 
2090 	nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2091 	nfc_digital_set_drvdata(trf->ddev, trf);
2092 	spi_set_drvdata(spi, trf);
2093 
2094 	autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2095 
2096 	pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2097 	pm_runtime_use_autosuspend(trf->dev);
2098 
2099 	ret = trf7970a_startup(trf);
2100 	if (ret)
2101 		goto err_free_ddev;
2102 
2103 	ret = nfc_digital_register_device(trf->ddev);
2104 	if (ret) {
2105 		dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2106 				ret);
2107 		goto err_shutdown;
2108 	}
2109 
2110 	return 0;
2111 
2112 err_shutdown:
2113 	trf7970a_shutdown(trf);
2114 err_free_ddev:
2115 	nfc_digital_free_device(trf->ddev);
2116 err_disable_regulator:
2117 	regulator_disable(trf->regulator);
2118 err_destroy_lock:
2119 	mutex_destroy(&trf->lock);
2120 	return ret;
2121 }
2122 
2123 static int trf7970a_remove(struct spi_device *spi)
2124 {
2125 	struct trf7970a *trf = spi_get_drvdata(spi);
2126 
2127 	mutex_lock(&trf->lock);
2128 
2129 	trf7970a_shutdown(trf);
2130 
2131 	mutex_unlock(&trf->lock);
2132 
2133 	nfc_digital_unregister_device(trf->ddev);
2134 	nfc_digital_free_device(trf->ddev);
2135 
2136 	regulator_disable(trf->regulator);
2137 
2138 	mutex_destroy(&trf->lock);
2139 
2140 	return 0;
2141 }
2142 
2143 #ifdef CONFIG_PM_SLEEP
2144 static int trf7970a_suspend(struct device *dev)
2145 {
2146 	struct spi_device *spi = to_spi_device(dev);
2147 	struct trf7970a *trf = spi_get_drvdata(spi);
2148 
2149 	dev_dbg(dev, "Suspend\n");
2150 
2151 	mutex_lock(&trf->lock);
2152 
2153 	trf7970a_shutdown(trf);
2154 
2155 	mutex_unlock(&trf->lock);
2156 
2157 	return 0;
2158 }
2159 
2160 static int trf7970a_resume(struct device *dev)
2161 {
2162 	struct spi_device *spi = to_spi_device(dev);
2163 	struct trf7970a *trf = spi_get_drvdata(spi);
2164 	int ret;
2165 
2166 	dev_dbg(dev, "Resume\n");
2167 
2168 	mutex_lock(&trf->lock);
2169 
2170 	ret = trf7970a_startup(trf);
2171 
2172 	mutex_unlock(&trf->lock);
2173 
2174 	return ret;
2175 }
2176 #endif
2177 
2178 #ifdef CONFIG_PM
2179 static int trf7970a_pm_runtime_suspend(struct device *dev)
2180 {
2181 	struct spi_device *spi = to_spi_device(dev);
2182 	struct trf7970a *trf = spi_get_drvdata(spi);
2183 	int ret;
2184 
2185 	dev_dbg(dev, "Runtime suspend\n");
2186 
2187 	mutex_lock(&trf->lock);
2188 
2189 	ret = trf7970a_power_down(trf);
2190 
2191 	mutex_unlock(&trf->lock);
2192 
2193 	return ret;
2194 }
2195 
2196 static int trf7970a_pm_runtime_resume(struct device *dev)
2197 {
2198 	struct spi_device *spi = to_spi_device(dev);
2199 	struct trf7970a *trf = spi_get_drvdata(spi);
2200 	int ret;
2201 
2202 	dev_dbg(dev, "Runtime resume\n");
2203 
2204 	ret = trf7970a_power_up(trf);
2205 	if (!ret)
2206 		pm_runtime_mark_last_busy(dev);
2207 
2208 	return ret;
2209 }
2210 #endif
2211 
2212 static const struct dev_pm_ops trf7970a_pm_ops = {
2213 	SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2214 	SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2215 			trf7970a_pm_runtime_resume, NULL)
2216 };
2217 
2218 static const struct of_device_id trf7970a_of_match[] = {
2219 	{ .compatible = "ti,trf7970a", },
2220 	{ /* sentinel */ },
2221 };
2222 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2223 
2224 static const struct spi_device_id trf7970a_id_table[] = {
2225 	{ "trf7970a", 0 },
2226 	{ }
2227 };
2228 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2229 
2230 static struct spi_driver trf7970a_spi_driver = {
2231 	.probe		= trf7970a_probe,
2232 	.remove		= trf7970a_remove,
2233 	.id_table	= trf7970a_id_table,
2234 	.driver		= {
2235 		.name	= "trf7970a",
2236 		.of_match_table = of_match_ptr(trf7970a_of_match),
2237 		.pm	= &trf7970a_pm_ops,
2238 	},
2239 };
2240 
2241 module_spi_driver(trf7970a_spi_driver);
2242 
2243 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2244 MODULE_LICENSE("GPL v2");
2245 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2246