1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI TRF7970a RFID/NFC Transceiver Driver
4 *
5 * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
6 *
7 * Author: Erick Macias <emacias@ti.com>
8 * Author: Felipe Balbi <balbi@ti.com>
9 * Author: Mark A. Greer <mgreer@animalcreek.com>
10 */
11
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/netdevice.h>
15 #include <linux/interrupt.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/nfc.h>
18 #include <linux/skbuff.h>
19 #include <linux/delay.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/of.h>
22 #include <linux/spi/spi.h>
23 #include <linux/regulator/consumer.h>
24
25 #include <net/nfc/nfc.h>
26 #include <net/nfc/digital.h>
27
28 /* There are 3 ways the host can communicate with the trf7970a:
29 * parallel mode, SPI with Slave Select (SS) mode, and SPI without
30 * SS mode. The driver only supports the two SPI modes.
31 *
32 * The trf7970a is very timing sensitive and the VIN, EN2, and EN
33 * pins must asserted in that order and with specific delays in between.
34 * The delays used in the driver were provided by TI and have been
35 * confirmed to work with this driver. There is a bug with the current
36 * version of the trf7970a that requires that EN2 remain low no matter
37 * what. If it goes high, it will generate an RF field even when in
38 * passive target mode. TI has indicated that the chip will work okay
39 * when EN2 is left low. The 'en2-rf-quirk' device tree property
40 * indicates that trf7970a currently being used has the erratum and
41 * that EN2 must be kept low.
42 *
43 * Timeouts are implemented using the delayed workqueue kernel facility.
44 * Timeouts are required so things don't hang when there is no response
45 * from the trf7970a (or tag). Using this mechanism creates a race with
46 * interrupts, however. That is, an interrupt and a timeout could occur
47 * closely enough together that one is blocked by the mutex while the other
48 * executes. When the timeout handler executes first and blocks the
49 * interrupt handler, it will eventually set the state to IDLE so the
50 * interrupt handler will check the state and exit with no harm done.
51 * When the interrupt handler executes first and blocks the timeout handler,
52 * the cancel_delayed_work() call will know that it didn't cancel the
53 * work item (i.e., timeout) and will return zero. That return code is
54 * used by the timer handler to indicate that it should ignore the timeout
55 * once its unblocked.
56 *
57 * Aborting an active command isn't as simple as it seems because the only
58 * way to abort a command that's already been sent to the tag is so turn
59 * off power to the tag. If we do that, though, we'd have to go through
60 * the entire anticollision procedure again but the digital layer doesn't
61 * support that. So, if an abort is received before trf7970a_send_cmd()
62 * has sent the command to the tag, it simply returns -ECANCELED. If the
63 * command has already been sent to the tag, then the driver continues
64 * normally and recieves the response data (or error) but just before
65 * sending the data upstream, it frees the rx_skb and sends -ECANCELED
66 * upstream instead. If the command failed, that error will be sent
67 * upstream.
68 *
69 * When recieving data from a tag and the interrupt status register has
70 * only the SRX bit set, it means that all of the data has been received
71 * (once what's in the fifo has been read). However, depending on timing
72 * an interrupt status with only the SRX bit set may not be recived. In
73 * those cases, the timeout mechanism is used to wait 20 ms in case more
74 * data arrives. After 20 ms, it is assumed that all of the data has been
75 * received and the accumulated rx data is sent upstream. The
76 * 'TRF7970A_ST_WAIT_FOR_RX_DATA_CONT' state is used for this purpose
77 * (i.e., it indicates that some data has been received but we're not sure
78 * if there is more coming so a timeout in this state means all data has
79 * been received and there isn't an error). The delay is 20 ms since delays
80 * of ~16 ms have been observed during testing.
81 *
82 * When transmitting a frame larger than the FIFO size (127 bytes), the
83 * driver will wait 20 ms for the FIFO to drain past the low-watermark
84 * and generate an interrupt. The low-watermark set to 32 bytes so the
85 * interrupt should fire after 127 - 32 = 95 bytes have been sent. At
86 * the lowest possible bit rate (6.62 kbps for 15693), it will take up
87 * to ~14.35 ms so 20 ms is used for the timeout.
88 *
89 * Type 2 write and sector select commands respond with a 4-bit ACK or NACK.
90 * Having only 4 bits in the FIFO won't normally generate an interrupt so
91 * driver enables the '4_bit_RX' bit of the Special Functions register 1
92 * to cause an interrupt in that case. Leaving that bit for a read command
93 * messes up the data returned so it is only enabled when the framing is
94 * 'NFC_DIGITAL_FRAMING_NFCA_T2T' and the command is not a read command.
95 * Unfortunately, that means that the driver has to peek into tx frames
96 * when the framing is 'NFC_DIGITAL_FRAMING_NFCA_T2T'. This is done by
97 * the trf7970a_per_cmd_config() routine.
98 *
99 * ISO/IEC 15693 frames specify whether to use single or double sub-carrier
100 * frequencies and whether to use low or high data rates in the flags byte
101 * of the frame. This means that the driver has to peek at all 15693 frames
102 * to determine what speed to set the communication to. In addition, write
103 * and lock commands use the OPTION flag to indicate that an EOF must be
104 * sent to the tag before it will send its response. So the driver has to
105 * examine all frames for that reason too.
106 *
107 * It is unclear how long to wait before sending the EOF. According to the
108 * Note under Table 1-1 in section 1.6 of
109 * http://www.ti.com/lit/ug/scbu011/scbu011.pdf, that wait should be at least
110 * 10 ms for TI Tag-it HF-I tags; however testing has shown that is not long
111 * enough so 20 ms is used. So the timer is set to 40 ms - 20 ms to drain
112 * up to 127 bytes in the FIFO at the lowest bit rate plus another 20 ms to
113 * ensure the wait is long enough before sending the EOF. This seems to work
114 * reliably.
115 */
116
117 #define TRF7970A_SUPPORTED_PROTOCOLS \
118 (NFC_PROTO_MIFARE_MASK | NFC_PROTO_ISO14443_MASK | \
119 NFC_PROTO_ISO14443_B_MASK | NFC_PROTO_FELICA_MASK | \
120 NFC_PROTO_ISO15693_MASK | NFC_PROTO_NFC_DEP_MASK)
121
122 #define TRF7970A_AUTOSUSPEND_DELAY 30000 /* 30 seconds */
123 #define TRF7970A_13MHZ_CLOCK_FREQUENCY 13560000
124 #define TRF7970A_27MHZ_CLOCK_FREQUENCY 27120000
125
126 #define TRF7970A_RX_SKB_ALLOC_SIZE 256
127
128 #define TRF7970A_FIFO_SIZE 127
129
130 /* TX length is 3 nibbles long ==> 4KB - 1 bytes max */
131 #define TRF7970A_TX_MAX (4096 - 1)
132
133 #define TRF7970A_WAIT_FOR_TX_IRQ 20
134 #define TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT 20
135 #define TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT 20
136 #define TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF 40
137
138 /* Guard times for various RF technologies (in us) */
139 #define TRF7970A_GUARD_TIME_NFCA 5000
140 #define TRF7970A_GUARD_TIME_NFCB 5000
141 #define TRF7970A_GUARD_TIME_NFCF 20000
142 #define TRF7970A_GUARD_TIME_15693 1000
143
144 /* Quirks */
145 /* Erratum: When reading IRQ Status register on trf7970a, we must issue a
146 * read continuous command for IRQ Status and Collision Position registers.
147 */
148 #define TRF7970A_QUIRK_IRQ_STATUS_READ BIT(0)
149 #define TRF7970A_QUIRK_EN2_MUST_STAY_LOW BIT(1)
150
151 /* Direct commands */
152 #define TRF7970A_CMD_IDLE 0x00
153 #define TRF7970A_CMD_SOFT_INIT 0x03
154 #define TRF7970A_CMD_RF_COLLISION 0x04
155 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_N 0x05
156 #define TRF7970A_CMD_RF_COLLISION_RESPONSE_0 0x06
157 #define TRF7970A_CMD_FIFO_RESET 0x0f
158 #define TRF7970A_CMD_TRANSMIT_NO_CRC 0x10
159 #define TRF7970A_CMD_TRANSMIT 0x11
160 #define TRF7970A_CMD_DELAY_TRANSMIT_NO_CRC 0x12
161 #define TRF7970A_CMD_DELAY_TRANSMIT 0x13
162 #define TRF7970A_CMD_EOF 0x14
163 #define TRF7970A_CMD_CLOSE_SLOT 0x15
164 #define TRF7970A_CMD_BLOCK_RX 0x16
165 #define TRF7970A_CMD_ENABLE_RX 0x17
166 #define TRF7970A_CMD_TEST_INT_RF 0x18
167 #define TRF7970A_CMD_TEST_EXT_RF 0x19
168 #define TRF7970A_CMD_RX_GAIN_ADJUST 0x1a
169
170 /* Bits determining whether its a direct command or register R/W,
171 * whether to use a continuous SPI transaction or not, and the actual
172 * direct cmd opcode or register address.
173 */
174 #define TRF7970A_CMD_BIT_CTRL BIT(7)
175 #define TRF7970A_CMD_BIT_RW BIT(6)
176 #define TRF7970A_CMD_BIT_CONTINUOUS BIT(5)
177 #define TRF7970A_CMD_BIT_OPCODE(opcode) ((opcode) & 0x1f)
178
179 /* Registers addresses */
180 #define TRF7970A_CHIP_STATUS_CTRL 0x00
181 #define TRF7970A_ISO_CTRL 0x01
182 #define TRF7970A_ISO14443B_TX_OPTIONS 0x02
183 #define TRF7970A_ISO14443A_HIGH_BITRATE_OPTIONS 0x03
184 #define TRF7970A_TX_TIMER_SETTING_H_BYTE 0x04
185 #define TRF7970A_TX_TIMER_SETTING_L_BYTE 0x05
186 #define TRF7970A_TX_PULSE_LENGTH_CTRL 0x06
187 #define TRF7970A_RX_NO_RESPONSE_WAIT 0x07
188 #define TRF7970A_RX_WAIT_TIME 0x08
189 #define TRF7970A_MODULATOR_SYS_CLK_CTRL 0x09
190 #define TRF7970A_RX_SPECIAL_SETTINGS 0x0a
191 #define TRF7970A_REG_IO_CTRL 0x0b
192 #define TRF7970A_IRQ_STATUS 0x0c
193 #define TRF7970A_COLLISION_IRQ_MASK 0x0d
194 #define TRF7970A_COLLISION_POSITION 0x0e
195 #define TRF7970A_RSSI_OSC_STATUS 0x0f
196 #define TRF7970A_SPECIAL_FCN_REG1 0x10
197 #define TRF7970A_SPECIAL_FCN_REG2 0x11
198 #define TRF7970A_RAM1 0x12
199 #define TRF7970A_RAM2 0x13
200 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS 0x14
201 #define TRF7970A_NFC_LOW_FIELD_LEVEL 0x16
202 #define TRF7970A_NFCID1 0x17
203 #define TRF7970A_NFC_TARGET_LEVEL 0x18
204 #define TRF79070A_NFC_TARGET_PROTOCOL 0x19
205 #define TRF7970A_TEST_REGISTER1 0x1a
206 #define TRF7970A_TEST_REGISTER2 0x1b
207 #define TRF7970A_FIFO_STATUS 0x1c
208 #define TRF7970A_TX_LENGTH_BYTE1 0x1d
209 #define TRF7970A_TX_LENGTH_BYTE2 0x1e
210 #define TRF7970A_FIFO_IO_REGISTER 0x1f
211
212 /* Chip Status Control Register Bits */
213 #define TRF7970A_CHIP_STATUS_VRS5_3 BIT(0)
214 #define TRF7970A_CHIP_STATUS_REC_ON BIT(1)
215 #define TRF7970A_CHIP_STATUS_AGC_ON BIT(2)
216 #define TRF7970A_CHIP_STATUS_PM_ON BIT(3)
217 #define TRF7970A_CHIP_STATUS_RF_PWR BIT(4)
218 #define TRF7970A_CHIP_STATUS_RF_ON BIT(5)
219 #define TRF7970A_CHIP_STATUS_DIRECT BIT(6)
220 #define TRF7970A_CHIP_STATUS_STBY BIT(7)
221
222 /* ISO Control Register Bits */
223 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_662 0x00
224 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_662 0x01
225 #define TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648 0x02
226 #define TRF7970A_ISO_CTRL_15693_SGL_1OF256_2648 0x03
227 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a 0x04
228 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_667 0x05
229 #define TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669 0x06
230 #define TRF7970A_ISO_CTRL_15693_DBL_1OF256_2669 0x07
231 #define TRF7970A_ISO_CTRL_14443A_106 0x08
232 #define TRF7970A_ISO_CTRL_14443A_212 0x09
233 #define TRF7970A_ISO_CTRL_14443A_424 0x0a
234 #define TRF7970A_ISO_CTRL_14443A_848 0x0b
235 #define TRF7970A_ISO_CTRL_14443B_106 0x0c
236 #define TRF7970A_ISO_CTRL_14443B_212 0x0d
237 #define TRF7970A_ISO_CTRL_14443B_424 0x0e
238 #define TRF7970A_ISO_CTRL_14443B_848 0x0f
239 #define TRF7970A_ISO_CTRL_FELICA_212 0x1a
240 #define TRF7970A_ISO_CTRL_FELICA_424 0x1b
241 #define TRF7970A_ISO_CTRL_NFC_NFCA_106 0x01
242 #define TRF7970A_ISO_CTRL_NFC_NFCF_212 0x02
243 #define TRF7970A_ISO_CTRL_NFC_NFCF_424 0x03
244 #define TRF7970A_ISO_CTRL_NFC_CE_14443A 0x00
245 #define TRF7970A_ISO_CTRL_NFC_CE_14443B 0x01
246 #define TRF7970A_ISO_CTRL_NFC_CE BIT(2)
247 #define TRF7970A_ISO_CTRL_NFC_ACTIVE BIT(3)
248 #define TRF7970A_ISO_CTRL_NFC_INITIATOR BIT(4)
249 #define TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE BIT(5)
250 #define TRF7970A_ISO_CTRL_RFID BIT(5)
251 #define TRF7970A_ISO_CTRL_DIR_MODE BIT(6)
252 #define TRF7970A_ISO_CTRL_RX_CRC_N BIT(7) /* true == No CRC */
253
254 #define TRF7970A_ISO_CTRL_RFID_SPEED_MASK 0x1f
255
256 /* Modulator and SYS_CLK Control Register Bits */
257 #define TRF7970A_MODULATOR_DEPTH(n) ((n) & 0x7)
258 #define TRF7970A_MODULATOR_DEPTH_ASK10 (TRF7970A_MODULATOR_DEPTH(0))
259 #define TRF7970A_MODULATOR_DEPTH_OOK (TRF7970A_MODULATOR_DEPTH(1))
260 #define TRF7970A_MODULATOR_DEPTH_ASK7 (TRF7970A_MODULATOR_DEPTH(2))
261 #define TRF7970A_MODULATOR_DEPTH_ASK8_5 (TRF7970A_MODULATOR_DEPTH(3))
262 #define TRF7970A_MODULATOR_DEPTH_ASK13 (TRF7970A_MODULATOR_DEPTH(4))
263 #define TRF7970A_MODULATOR_DEPTH_ASK16 (TRF7970A_MODULATOR_DEPTH(5))
264 #define TRF7970A_MODULATOR_DEPTH_ASK22 (TRF7970A_MODULATOR_DEPTH(6))
265 #define TRF7970A_MODULATOR_DEPTH_ASK30 (TRF7970A_MODULATOR_DEPTH(7))
266 #define TRF7970A_MODULATOR_EN_ANA BIT(3)
267 #define TRF7970A_MODULATOR_CLK(n) (((n) & 0x3) << 4)
268 #define TRF7970A_MODULATOR_CLK_DISABLED (TRF7970A_MODULATOR_CLK(0))
269 #define TRF7970A_MODULATOR_CLK_3_6 (TRF7970A_MODULATOR_CLK(1))
270 #define TRF7970A_MODULATOR_CLK_6_13 (TRF7970A_MODULATOR_CLK(2))
271 #define TRF7970A_MODULATOR_CLK_13_27 (TRF7970A_MODULATOR_CLK(3))
272 #define TRF7970A_MODULATOR_EN_OOK BIT(6)
273 #define TRF7970A_MODULATOR_27MHZ BIT(7)
274
275 #define TRF7970A_RX_GAIN_REDUCTION_MAX_DB 15
276 #define TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB 5
277 #define TRF7970A_RX_SPECIAL_SETTINGS_NO_LIM BIT(0)
278 #define TRF7970A_RX_SPECIAL_SETTINGS_AGCR BIT(1)
279 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT 2
280 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX (0x3)
281 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK (TRF7970A_RX_SPECIAL_SETTINGS_GD_MAX << \
282 TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
283 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_0DB (0x0 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
284 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_5DB (0x1 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
285 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_10DB (0x2 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
286 #define TRF7970A_RX_SPECIAL_SETTINGS_GD_15DB (0x3 << TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT)
287 #define TRF7970A_RX_SPECIAL_SETTINGS_HBT BIT(4)
288 #define TRF7970A_RX_SPECIAL_SETTINGS_M848 BIT(5)
289 #define TRF7970A_RX_SPECIAL_SETTINGS_C424 BIT(6)
290 #define TRF7970A_RX_SPECIAL_SETTINGS_C212 BIT(7)
291
292 #define TRF7970A_REG_IO_CTRL_VRS(v) ((v) & 0x07)
293 #define TRF7970A_REG_IO_CTRL_IO_LOW BIT(5)
294 #define TRF7970A_REG_IO_CTRL_EN_EXT_PA BIT(6)
295 #define TRF7970A_REG_IO_CTRL_AUTO_REG BIT(7)
296
297 /* IRQ Status Register Bits */
298 #define TRF7970A_IRQ_STATUS_NORESP BIT(0) /* ISO15693 only */
299 #define TRF7970A_IRQ_STATUS_NFC_COL_ERROR BIT(0)
300 #define TRF7970A_IRQ_STATUS_COL BIT(1)
301 #define TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR BIT(2)
302 #define TRF7970A_IRQ_STATUS_NFC_RF BIT(2)
303 #define TRF7970A_IRQ_STATUS_PARITY_ERROR BIT(3)
304 #define TRF7970A_IRQ_STATUS_NFC_SDD BIT(3)
305 #define TRF7970A_IRQ_STATUS_CRC_ERROR BIT(4)
306 #define TRF7970A_IRQ_STATUS_NFC_PROTO_ERROR BIT(4)
307 #define TRF7970A_IRQ_STATUS_FIFO BIT(5)
308 #define TRF7970A_IRQ_STATUS_SRX BIT(6)
309 #define TRF7970A_IRQ_STATUS_TX BIT(7)
310
311 #define TRF7970A_IRQ_STATUS_ERROR \
312 (TRF7970A_IRQ_STATUS_COL | \
313 TRF7970A_IRQ_STATUS_FRAMING_EOF_ERROR | \
314 TRF7970A_IRQ_STATUS_PARITY_ERROR | \
315 TRF7970A_IRQ_STATUS_CRC_ERROR)
316
317 #define TRF7970A_RSSI_OSC_STATUS_RSSI_MASK (BIT(2) | BIT(1) | BIT(0))
318 #define TRF7970A_RSSI_OSC_STATUS_RSSI_X_MASK (BIT(5) | BIT(4) | BIT(3))
319 #define TRF7970A_RSSI_OSC_STATUS_RSSI_OSC_OK BIT(6)
320
321 #define TRF7970A_SPECIAL_FCN_REG1_COL_7_6 BIT(0)
322 #define TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL BIT(1)
323 #define TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX BIT(2)
324 #define TRF7970A_SPECIAL_FCN_REG1_SP_DIR_MODE BIT(3)
325 #define TRF7970A_SPECIAL_FCN_REG1_NEXT_SLOT_37US BIT(4)
326 #define TRF7970A_SPECIAL_FCN_REG1_PAR43 BIT(5)
327
328 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_124 (0x0 << 2)
329 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_120 (0x1 << 2)
330 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_112 (0x2 << 2)
331 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 (0x3 << 2)
332 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_4 0x0
333 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_8 0x1
334 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_16 0x2
335 #define TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32 0x3
336
337 #define TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(v) ((v) & 0x07)
338 #define TRF7970A_NFC_LOW_FIELD_LEVEL_CLEX_DIS BIT(7)
339
340 #define TRF7970A_NFC_TARGET_LEVEL_RFDET(v) ((v) & 0x07)
341 #define TRF7970A_NFC_TARGET_LEVEL_HI_RF BIT(3)
342 #define TRF7970A_NFC_TARGET_LEVEL_SDD_EN BIT(5)
343 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_4BYTES (0x0 << 6)
344 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_7BYTES (0x1 << 6)
345 #define TRF7970A_NFC_TARGET_LEVEL_LD_S_10BYTES (0x2 << 6)
346
347 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106 BIT(0)
348 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212 BIT(1)
349 #define TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424 (BIT(0) | BIT(1))
350 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B BIT(2)
351 #define TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 BIT(3)
352 #define TRF79070A_NFC_TARGET_PROTOCOL_FELICA BIT(4)
353 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_L BIT(6)
354 #define TRF79070A_NFC_TARGET_PROTOCOL_RF_H BIT(7)
355
356 #define TRF79070A_NFC_TARGET_PROTOCOL_106A \
357 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
358 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
359 TRF79070A_NFC_TARGET_PROTOCOL_PAS_106 | \
360 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
361
362 #define TRF79070A_NFC_TARGET_PROTOCOL_106B \
363 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
364 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
365 TRF79070A_NFC_TARGET_PROTOCOL_PAS_14443B | \
366 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_106)
367
368 #define TRF79070A_NFC_TARGET_PROTOCOL_212F \
369 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
370 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
371 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
372 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_212)
373
374 #define TRF79070A_NFC_TARGET_PROTOCOL_424F \
375 (TRF79070A_NFC_TARGET_PROTOCOL_RF_H | \
376 TRF79070A_NFC_TARGET_PROTOCOL_RF_L | \
377 TRF79070A_NFC_TARGET_PROTOCOL_FELICA | \
378 TRF79070A_NFC_TARGET_PROTOCOL_NFCBR_424)
379
380 #define TRF7970A_FIFO_STATUS_OVERFLOW BIT(7)
381
382 /* NFC (ISO/IEC 14443A) Type 2 Tag commands */
383 #define NFC_T2T_CMD_READ 0x30
384
385 /* ISO 15693 commands codes */
386 #define ISO15693_CMD_INVENTORY 0x01
387 #define ISO15693_CMD_READ_SINGLE_BLOCK 0x20
388 #define ISO15693_CMD_WRITE_SINGLE_BLOCK 0x21
389 #define ISO15693_CMD_LOCK_BLOCK 0x22
390 #define ISO15693_CMD_READ_MULTIPLE_BLOCK 0x23
391 #define ISO15693_CMD_WRITE_MULTIPLE_BLOCK 0x24
392 #define ISO15693_CMD_SELECT 0x25
393 #define ISO15693_CMD_RESET_TO_READY 0x26
394 #define ISO15693_CMD_WRITE_AFI 0x27
395 #define ISO15693_CMD_LOCK_AFI 0x28
396 #define ISO15693_CMD_WRITE_DSFID 0x29
397 #define ISO15693_CMD_LOCK_DSFID 0x2a
398 #define ISO15693_CMD_GET_SYSTEM_INFO 0x2b
399 #define ISO15693_CMD_GET_MULTIPLE_BLOCK_SECURITY_STATUS 0x2c
400
401 /* ISO 15693 request and response flags */
402 #define ISO15693_REQ_FLAG_SUB_CARRIER BIT(0)
403 #define ISO15693_REQ_FLAG_DATA_RATE BIT(1)
404 #define ISO15693_REQ_FLAG_INVENTORY BIT(2)
405 #define ISO15693_REQ_FLAG_PROTOCOL_EXT BIT(3)
406 #define ISO15693_REQ_FLAG_SELECT BIT(4)
407 #define ISO15693_REQ_FLAG_AFI BIT(4)
408 #define ISO15693_REQ_FLAG_ADDRESS BIT(5)
409 #define ISO15693_REQ_FLAG_NB_SLOTS BIT(5)
410 #define ISO15693_REQ_FLAG_OPTION BIT(6)
411
412 #define ISO15693_REQ_FLAG_SPEED_MASK \
413 (ISO15693_REQ_FLAG_SUB_CARRIER | ISO15693_REQ_FLAG_DATA_RATE)
414
415 enum trf7970a_state {
416 TRF7970A_ST_PWR_OFF,
417 TRF7970A_ST_RF_OFF,
418 TRF7970A_ST_IDLE,
419 TRF7970A_ST_IDLE_RX_BLOCKED,
420 TRF7970A_ST_WAIT_FOR_TX_FIFO,
421 TRF7970A_ST_WAIT_FOR_RX_DATA,
422 TRF7970A_ST_WAIT_FOR_RX_DATA_CONT,
423 TRF7970A_ST_WAIT_TO_ISSUE_EOF,
424 TRF7970A_ST_LISTENING,
425 TRF7970A_ST_LISTENING_MD,
426 TRF7970A_ST_MAX
427 };
428
429 struct trf7970a {
430 enum trf7970a_state state;
431 struct device *dev;
432 struct spi_device *spi;
433 struct regulator *vin_regulator;
434 struct regulator *vddio_regulator;
435 struct nfc_digital_dev *ddev;
436 u32 quirks;
437 bool is_initiator;
438 bool aborting;
439 struct sk_buff *tx_skb;
440 struct sk_buff *rx_skb;
441 nfc_digital_cmd_complete_t cb;
442 void *cb_arg;
443 u8 chip_status_ctrl;
444 u8 iso_ctrl;
445 u8 iso_ctrl_tech;
446 u8 modulator_sys_clk_ctrl;
447 u8 special_fcn_reg1;
448 u8 io_ctrl;
449 unsigned int guard_time;
450 int technology;
451 int framing;
452 u8 md_rf_tech;
453 u8 tx_cmd;
454 bool issue_eof;
455 struct gpio_desc *en_gpiod;
456 struct gpio_desc *en2_gpiod;
457 struct mutex lock;
458 unsigned int timeout;
459 bool ignore_timeout;
460 struct delayed_work timeout_work;
461 u8 rx_gain_reduction;
462 bool custom_rx_gain_reduction;
463 };
464
trf7970a_cmd(struct trf7970a * trf,u8 opcode)465 static int trf7970a_cmd(struct trf7970a *trf, u8 opcode)
466 {
467 u8 cmd = TRF7970A_CMD_BIT_CTRL | TRF7970A_CMD_BIT_OPCODE(opcode);
468 int ret;
469
470 dev_dbg(trf->dev, "cmd: 0x%x\n", cmd);
471
472 ret = spi_write(trf->spi, &cmd, 1);
473 if (ret)
474 dev_err(trf->dev, "%s - cmd: 0x%x, ret: %d\n", __func__, cmd,
475 ret);
476 return ret;
477 }
478
trf7970a_read(struct trf7970a * trf,u8 reg,u8 * val)479 static int trf7970a_read(struct trf7970a *trf, u8 reg, u8 *val)
480 {
481 u8 addr = TRF7970A_CMD_BIT_RW | reg;
482 int ret;
483
484 ret = spi_write_then_read(trf->spi, &addr, 1, val, 1);
485 if (ret)
486 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
487 ret);
488
489 dev_dbg(trf->dev, "read(0x%x): 0x%x\n", addr, *val);
490
491 return ret;
492 }
493
trf7970a_read_cont(struct trf7970a * trf,u8 reg,u8 * buf,size_t len)494 static int trf7970a_read_cont(struct trf7970a *trf, u8 reg, u8 *buf,
495 size_t len)
496 {
497 u8 addr = reg | TRF7970A_CMD_BIT_RW | TRF7970A_CMD_BIT_CONTINUOUS;
498 struct spi_transfer t[2];
499 struct spi_message m;
500 int ret;
501
502 dev_dbg(trf->dev, "read_cont(0x%x, %zd)\n", addr, len);
503
504 spi_message_init(&m);
505
506 memset(&t, 0, sizeof(t));
507
508 t[0].tx_buf = &addr;
509 t[0].len = sizeof(addr);
510 spi_message_add_tail(&t[0], &m);
511
512 t[1].rx_buf = buf;
513 t[1].len = len;
514 spi_message_add_tail(&t[1], &m);
515
516 ret = spi_sync(trf->spi, &m);
517 if (ret)
518 dev_err(trf->dev, "%s - addr: 0x%x, ret: %d\n", __func__, addr,
519 ret);
520 return ret;
521 }
522
trf7970a_write(struct trf7970a * trf,u8 reg,u8 val)523 static int trf7970a_write(struct trf7970a *trf, u8 reg, u8 val)
524 {
525 u8 buf[2] = { reg, val };
526 int ret;
527
528 dev_dbg(trf->dev, "write(0x%x): 0x%x\n", reg, val);
529
530 ret = spi_write(trf->spi, buf, 2);
531 if (ret)
532 dev_err(trf->dev, "%s - write: 0x%x 0x%x, ret: %d\n", __func__,
533 buf[0], buf[1], ret);
534
535 return ret;
536 }
537
trf7970a_read_irqstatus(struct trf7970a * trf,u8 * status)538 static int trf7970a_read_irqstatus(struct trf7970a *trf, u8 *status)
539 {
540 int ret;
541 u8 buf[2];
542 u8 addr;
543
544 addr = TRF7970A_IRQ_STATUS | TRF7970A_CMD_BIT_RW;
545
546 if (trf->quirks & TRF7970A_QUIRK_IRQ_STATUS_READ) {
547 addr |= TRF7970A_CMD_BIT_CONTINUOUS;
548 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
549 } else {
550 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 1);
551 }
552
553 if (ret)
554 dev_err(trf->dev, "%s - irqstatus: Status read failed: %d\n",
555 __func__, ret);
556 else
557 *status = buf[0];
558
559 return ret;
560 }
561
trf7970a_update_rx_gain_reduction(struct trf7970a * trf)562 static int trf7970a_update_rx_gain_reduction(struct trf7970a *trf)
563 {
564 int ret = 0;
565 u8 reg;
566
567 if (!trf->custom_rx_gain_reduction)
568 return 0;
569
570 ret = trf7970a_read(trf, TRF7970A_RX_SPECIAL_SETTINGS, ®);
571 if (ret)
572 return ret;
573 reg &= ~(TRF7970A_RX_SPECIAL_SETTINGS_GD_MASK);
574 reg |= trf->rx_gain_reduction;
575
576 ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS, reg);
577
578 return ret;
579 }
580
trf7970a_update_iso_ctrl_register(struct trf7970a * trf,u8 iso_ctrl)581 static int trf7970a_update_iso_ctrl_register(struct trf7970a *trf, u8 iso_ctrl)
582 {
583 int ret;
584
585 ret = trf7970a_write(trf, TRF7970A_ISO_CTRL, iso_ctrl);
586 if (ret)
587 return ret;
588 /*
589 * Every time the ISO_CTRL register is written, the RX special setting register is reset by
590 * the chip. When a custom gain reguduction is required, it should be rewritten now.
591 */
592 ret = trf7970a_update_rx_gain_reduction(trf);
593
594 return ret;
595 }
596
trf7970a_read_target_proto(struct trf7970a * trf,u8 * target_proto)597 static int trf7970a_read_target_proto(struct trf7970a *trf, u8 *target_proto)
598 {
599 int ret;
600 u8 buf[2];
601 u8 addr;
602
603 addr = TRF79070A_NFC_TARGET_PROTOCOL | TRF7970A_CMD_BIT_RW |
604 TRF7970A_CMD_BIT_CONTINUOUS;
605
606 ret = spi_write_then_read(trf->spi, &addr, 1, buf, 2);
607 if (ret)
608 dev_err(trf->dev, "%s - target_proto: Read failed: %d\n",
609 __func__, ret);
610 else
611 *target_proto = buf[0];
612
613 return ret;
614 }
615
trf7970a_mode_detect(struct trf7970a * trf,u8 * rf_tech)616 static int trf7970a_mode_detect(struct trf7970a *trf, u8 *rf_tech)
617 {
618 int ret;
619 u8 target_proto, tech;
620
621 ret = trf7970a_read_target_proto(trf, &target_proto);
622 if (ret)
623 return ret;
624
625 switch (target_proto) {
626 case TRF79070A_NFC_TARGET_PROTOCOL_106A:
627 tech = NFC_DIGITAL_RF_TECH_106A;
628 break;
629 case TRF79070A_NFC_TARGET_PROTOCOL_106B:
630 tech = NFC_DIGITAL_RF_TECH_106B;
631 break;
632 case TRF79070A_NFC_TARGET_PROTOCOL_212F:
633 tech = NFC_DIGITAL_RF_TECH_212F;
634 break;
635 case TRF79070A_NFC_TARGET_PROTOCOL_424F:
636 tech = NFC_DIGITAL_RF_TECH_424F;
637 break;
638 default:
639 dev_dbg(trf->dev, "%s - mode_detect: target_proto: 0x%x\n",
640 __func__, target_proto);
641 return -EIO;
642 }
643
644 *rf_tech = tech;
645
646 return ret;
647 }
648
trf7970a_send_upstream(struct trf7970a * trf)649 static void trf7970a_send_upstream(struct trf7970a *trf)
650 {
651 dev_kfree_skb_any(trf->tx_skb);
652 trf->tx_skb = NULL;
653
654 if (trf->rx_skb && !IS_ERR(trf->rx_skb) && !trf->aborting)
655 print_hex_dump_debug("trf7970a rx data: ", DUMP_PREFIX_NONE,
656 16, 1, trf->rx_skb->data, trf->rx_skb->len,
657 false);
658
659 trf->state = TRF7970A_ST_IDLE;
660
661 if (trf->aborting) {
662 dev_dbg(trf->dev, "Abort process complete\n");
663
664 if (!IS_ERR(trf->rx_skb)) {
665 kfree_skb(trf->rx_skb);
666 trf->rx_skb = ERR_PTR(-ECANCELED);
667 }
668
669 trf->aborting = false;
670 }
671
672 trf->cb(trf->ddev, trf->cb_arg, trf->rx_skb);
673
674 trf->rx_skb = NULL;
675 }
676
trf7970a_send_err_upstream(struct trf7970a * trf,int errno)677 static void trf7970a_send_err_upstream(struct trf7970a *trf, int errno)
678 {
679 dev_dbg(trf->dev, "Error - state: %d, errno: %d\n", trf->state, errno);
680
681 cancel_delayed_work(&trf->timeout_work);
682
683 kfree_skb(trf->rx_skb);
684 trf->rx_skb = ERR_PTR(errno);
685
686 trf7970a_send_upstream(trf);
687 }
688
trf7970a_transmit(struct trf7970a * trf,struct sk_buff * skb,unsigned int len,const u8 * prefix,unsigned int prefix_len)689 static int trf7970a_transmit(struct trf7970a *trf, struct sk_buff *skb,
690 unsigned int len, const u8 *prefix,
691 unsigned int prefix_len)
692 {
693 struct spi_transfer t[2];
694 struct spi_message m;
695 unsigned int timeout;
696 int ret;
697
698 print_hex_dump_debug("trf7970a tx data: ", DUMP_PREFIX_NONE,
699 16, 1, skb->data, len, false);
700
701 spi_message_init(&m);
702
703 memset(&t, 0, sizeof(t));
704
705 t[0].tx_buf = prefix;
706 t[0].len = prefix_len;
707 spi_message_add_tail(&t[0], &m);
708
709 t[1].tx_buf = skb->data;
710 t[1].len = len;
711 spi_message_add_tail(&t[1], &m);
712
713 ret = spi_sync(trf->spi, &m);
714 if (ret) {
715 dev_err(trf->dev, "%s - Can't send tx data: %d\n", __func__,
716 ret);
717 return ret;
718 }
719
720 skb_pull(skb, len);
721
722 if (skb->len > 0) {
723 trf->state = TRF7970A_ST_WAIT_FOR_TX_FIFO;
724 timeout = TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT;
725 } else {
726 if (trf->issue_eof) {
727 trf->state = TRF7970A_ST_WAIT_TO_ISSUE_EOF;
728 timeout = TRF7970A_WAIT_TO_ISSUE_ISO15693_EOF;
729 } else {
730 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
731
732 if (!trf->timeout)
733 timeout = TRF7970A_WAIT_FOR_TX_IRQ;
734 else
735 timeout = trf->timeout;
736 }
737 }
738
739 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n", timeout,
740 trf->state);
741
742 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
743
744 return 0;
745 }
746
trf7970a_fill_fifo(struct trf7970a * trf)747 static void trf7970a_fill_fifo(struct trf7970a *trf)
748 {
749 struct sk_buff *skb = trf->tx_skb;
750 unsigned int len;
751 int ret;
752 u8 fifo_bytes;
753 u8 prefix;
754
755 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
756 if (ret) {
757 trf7970a_send_err_upstream(trf, ret);
758 return;
759 }
760
761 dev_dbg(trf->dev, "Filling FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
762
763 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
764
765 /* Calculate how much more data can be written to the fifo */
766 len = TRF7970A_FIFO_SIZE - fifo_bytes;
767 if (!len) {
768 schedule_delayed_work(&trf->timeout_work,
769 msecs_to_jiffies(TRF7970A_WAIT_FOR_FIFO_DRAIN_TIMEOUT));
770 return;
771 }
772
773 len = min(skb->len, len);
774
775 prefix = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_FIFO_IO_REGISTER;
776
777 ret = trf7970a_transmit(trf, skb, len, &prefix, sizeof(prefix));
778 if (ret)
779 trf7970a_send_err_upstream(trf, ret);
780 }
781
trf7970a_drain_fifo(struct trf7970a * trf,u8 status)782 static void trf7970a_drain_fifo(struct trf7970a *trf, u8 status)
783 {
784 struct sk_buff *skb = trf->rx_skb;
785 int ret;
786 u8 fifo_bytes;
787
788 if (status & TRF7970A_IRQ_STATUS_ERROR) {
789 trf7970a_send_err_upstream(trf, -EIO);
790 return;
791 }
792
793 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
794 if (ret) {
795 trf7970a_send_err_upstream(trf, ret);
796 return;
797 }
798
799 dev_dbg(trf->dev, "Draining FIFO - fifo_bytes: 0x%x\n", fifo_bytes);
800
801 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
802
803 if (!fifo_bytes)
804 goto no_rx_data;
805
806 if (fifo_bytes > skb_tailroom(skb)) {
807 skb = skb_copy_expand(skb, skb_headroom(skb),
808 max_t(int, fifo_bytes,
809 TRF7970A_RX_SKB_ALLOC_SIZE),
810 GFP_KERNEL);
811 if (!skb) {
812 trf7970a_send_err_upstream(trf, -ENOMEM);
813 return;
814 }
815
816 kfree_skb(trf->rx_skb);
817 trf->rx_skb = skb;
818 }
819
820 ret = trf7970a_read_cont(trf, TRF7970A_FIFO_IO_REGISTER,
821 skb_put(skb, fifo_bytes), fifo_bytes);
822 if (ret) {
823 trf7970a_send_err_upstream(trf, ret);
824 return;
825 }
826
827 /* If received Type 2 ACK/NACK, shift right 4 bits and pass up */
828 if ((trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T) && (skb->len == 1) &&
829 (trf->special_fcn_reg1 == TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX)) {
830 skb->data[0] >>= 4;
831 status = TRF7970A_IRQ_STATUS_SRX;
832 } else {
833 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA_CONT;
834
835 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS, &fifo_bytes);
836 if (ret) {
837 trf7970a_send_err_upstream(trf, ret);
838 return;
839 }
840
841 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
842
843 /* If there are bytes in the FIFO, set status to '0' so
844 * the if stmt below doesn't fire and the driver will wait
845 * for the trf7970a to generate another RX interrupt.
846 */
847 if (fifo_bytes)
848 status = 0;
849 }
850
851 no_rx_data:
852 if (status == TRF7970A_IRQ_STATUS_SRX) { /* Receive complete */
853 trf7970a_send_upstream(trf);
854 return;
855 }
856
857 dev_dbg(trf->dev, "Setting timeout for %d ms\n",
858 TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT);
859
860 schedule_delayed_work(&trf->timeout_work,
861 msecs_to_jiffies(TRF7970A_WAIT_FOR_RX_DATA_TIMEOUT));
862 }
863
trf7970a_irq(int irq,void * dev_id)864 static irqreturn_t trf7970a_irq(int irq, void *dev_id)
865 {
866 struct trf7970a *trf = dev_id;
867 int ret;
868 u8 status, fifo_bytes, iso_ctrl;
869
870 mutex_lock(&trf->lock);
871
872 if (trf->state == TRF7970A_ST_RF_OFF) {
873 mutex_unlock(&trf->lock);
874 return IRQ_NONE;
875 }
876
877 ret = trf7970a_read_irqstatus(trf, &status);
878 if (ret) {
879 mutex_unlock(&trf->lock);
880 return IRQ_NONE;
881 }
882
883 dev_dbg(trf->dev, "IRQ - state: %d, status: 0x%x\n", trf->state,
884 status);
885
886 if (!status) {
887 mutex_unlock(&trf->lock);
888 return IRQ_NONE;
889 }
890
891 switch (trf->state) {
892 case TRF7970A_ST_IDLE:
893 case TRF7970A_ST_IDLE_RX_BLOCKED:
894 /* If initiator and getting interrupts caused by RF noise,
895 * turn off the receiver to avoid unnecessary interrupts.
896 * It will be turned back on in trf7970a_send_cmd() when
897 * the next command is issued.
898 */
899 if (trf->is_initiator && (status & TRF7970A_IRQ_STATUS_ERROR)) {
900 trf7970a_cmd(trf, TRF7970A_CMD_BLOCK_RX);
901 trf->state = TRF7970A_ST_IDLE_RX_BLOCKED;
902 }
903
904 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
905 break;
906 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
907 if (status & TRF7970A_IRQ_STATUS_TX) {
908 trf->ignore_timeout =
909 !cancel_delayed_work(&trf->timeout_work);
910 trf7970a_fill_fifo(trf);
911 } else {
912 trf7970a_send_err_upstream(trf, -EIO);
913 }
914 break;
915 case TRF7970A_ST_WAIT_FOR_RX_DATA:
916 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
917 if (status & TRF7970A_IRQ_STATUS_SRX) {
918 trf->ignore_timeout =
919 !cancel_delayed_work(&trf->timeout_work);
920 trf7970a_drain_fifo(trf, status);
921 } else if (status & TRF7970A_IRQ_STATUS_FIFO) {
922 ret = trf7970a_read(trf, TRF7970A_FIFO_STATUS,
923 &fifo_bytes);
924
925 fifo_bytes &= ~TRF7970A_FIFO_STATUS_OVERFLOW;
926
927 if (ret)
928 trf7970a_send_err_upstream(trf, ret);
929 else if (!fifo_bytes)
930 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
931 } else if ((status == TRF7970A_IRQ_STATUS_TX) ||
932 (!trf->is_initiator &&
933 (status == (TRF7970A_IRQ_STATUS_TX |
934 TRF7970A_IRQ_STATUS_NFC_RF)))) {
935 trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
936
937 if (!trf->timeout) {
938 trf->ignore_timeout =
939 !cancel_delayed_work(&trf->timeout_work);
940 trf->rx_skb = ERR_PTR(0);
941 trf7970a_send_upstream(trf);
942 break;
943 }
944
945 if (trf->is_initiator)
946 break;
947
948 iso_ctrl = trf->iso_ctrl;
949
950 switch (trf->framing) {
951 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
952 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
953 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
954 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
955 break;
956 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
957 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
958 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
959 trf->iso_ctrl = 0xff; /* Force ISO_CTRL write */
960 break;
961 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
962 ret = trf7970a_write(trf,
963 TRF7970A_SPECIAL_FCN_REG1,
964 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL);
965 if (ret)
966 goto err_unlock_exit;
967
968 trf->special_fcn_reg1 =
969 TRF7970A_SPECIAL_FCN_REG1_14_ANTICOLL;
970 break;
971 default:
972 break;
973 }
974
975 if (iso_ctrl != trf->iso_ctrl) {
976 ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
977 if (ret)
978 goto err_unlock_exit;
979
980 trf->iso_ctrl = iso_ctrl;
981 }
982 } else {
983 trf7970a_send_err_upstream(trf, -EIO);
984 }
985 break;
986 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
987 if (status != TRF7970A_IRQ_STATUS_TX)
988 trf7970a_send_err_upstream(trf, -EIO);
989 break;
990 case TRF7970A_ST_LISTENING:
991 if (status & TRF7970A_IRQ_STATUS_SRX) {
992 trf->ignore_timeout =
993 !cancel_delayed_work(&trf->timeout_work);
994 trf7970a_drain_fifo(trf, status);
995 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
996 trf7970a_send_err_upstream(trf, -EIO);
997 }
998 break;
999 case TRF7970A_ST_LISTENING_MD:
1000 if (status & TRF7970A_IRQ_STATUS_SRX) {
1001 trf->ignore_timeout =
1002 !cancel_delayed_work(&trf->timeout_work);
1003
1004 ret = trf7970a_mode_detect(trf, &trf->md_rf_tech);
1005 if (ret) {
1006 trf7970a_send_err_upstream(trf, ret);
1007 } else {
1008 trf->state = TRF7970A_ST_LISTENING;
1009 trf7970a_drain_fifo(trf, status);
1010 }
1011 } else if (!(status & TRF7970A_IRQ_STATUS_NFC_RF)) {
1012 trf7970a_send_err_upstream(trf, -EIO);
1013 }
1014 break;
1015 default:
1016 dev_err(trf->dev, "%s - Driver in invalid state: %d\n",
1017 __func__, trf->state);
1018 }
1019
1020 err_unlock_exit:
1021 mutex_unlock(&trf->lock);
1022 return IRQ_HANDLED;
1023 }
1024
trf7970a_issue_eof(struct trf7970a * trf)1025 static void trf7970a_issue_eof(struct trf7970a *trf)
1026 {
1027 int ret;
1028
1029 dev_dbg(trf->dev, "Issuing EOF\n");
1030
1031 ret = trf7970a_cmd(trf, TRF7970A_CMD_FIFO_RESET);
1032 if (ret)
1033 trf7970a_send_err_upstream(trf, ret);
1034
1035 ret = trf7970a_cmd(trf, TRF7970A_CMD_EOF);
1036 if (ret)
1037 trf7970a_send_err_upstream(trf, ret);
1038
1039 trf->state = TRF7970A_ST_WAIT_FOR_RX_DATA;
1040
1041 dev_dbg(trf->dev, "Setting timeout for %d ms, state: %d\n",
1042 trf->timeout, trf->state);
1043
1044 schedule_delayed_work(&trf->timeout_work,
1045 msecs_to_jiffies(trf->timeout));
1046 }
1047
trf7970a_timeout_work_handler(struct work_struct * work)1048 static void trf7970a_timeout_work_handler(struct work_struct *work)
1049 {
1050 struct trf7970a *trf = container_of(work, struct trf7970a,
1051 timeout_work.work);
1052
1053 dev_dbg(trf->dev, "Timeout - state: %d, ignore_timeout: %d\n",
1054 trf->state, trf->ignore_timeout);
1055
1056 mutex_lock(&trf->lock);
1057
1058 if (trf->ignore_timeout)
1059 trf->ignore_timeout = false;
1060 else if (trf->state == TRF7970A_ST_WAIT_FOR_RX_DATA_CONT)
1061 trf7970a_drain_fifo(trf, TRF7970A_IRQ_STATUS_SRX);
1062 else if (trf->state == TRF7970A_ST_WAIT_TO_ISSUE_EOF)
1063 trf7970a_issue_eof(trf);
1064 else
1065 trf7970a_send_err_upstream(trf, -ETIMEDOUT);
1066
1067 mutex_unlock(&trf->lock);
1068 }
1069
trf7970a_init(struct trf7970a * trf)1070 static int trf7970a_init(struct trf7970a *trf)
1071 {
1072 int ret;
1073
1074 dev_dbg(trf->dev, "Initializing device - state: %d\n", trf->state);
1075
1076 ret = trf7970a_cmd(trf, TRF7970A_CMD_SOFT_INIT);
1077 if (ret)
1078 goto err_out;
1079
1080 /* Set the gain reduction after soft init */
1081 ret = trf7970a_update_rx_gain_reduction(trf);
1082 if (ret)
1083 goto err_out;
1084
1085 ret = trf7970a_cmd(trf, TRF7970A_CMD_IDLE);
1086 if (ret)
1087 goto err_out;
1088
1089 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1090 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1091 if (ret)
1092 goto err_out;
1093
1094 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1095 if (ret)
1096 goto err_out;
1097
1098 usleep_range(1000, 2000);
1099
1100 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1101
1102 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1103 trf->modulator_sys_clk_ctrl);
1104 if (ret)
1105 goto err_out;
1106
1107 ret = trf7970a_write(trf, TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS,
1108 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLH_96 |
1109 TRF7970A_ADJUTABLE_FIFO_IRQ_LEVELS_WLL_32);
1110 if (ret)
1111 goto err_out;
1112
1113 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1, 0);
1114 if (ret)
1115 goto err_out;
1116
1117 trf->special_fcn_reg1 = 0;
1118
1119 trf->iso_ctrl = 0xff;
1120 return 0;
1121
1122 err_out:
1123 dev_dbg(trf->dev, "Couldn't init device: %d\n", ret);
1124 return ret;
1125 }
1126
trf7970a_switch_rf_off(struct trf7970a * trf)1127 static void trf7970a_switch_rf_off(struct trf7970a *trf)
1128 {
1129 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1130 (trf->state == TRF7970A_ST_RF_OFF))
1131 return;
1132
1133 dev_dbg(trf->dev, "Switching rf off\n");
1134
1135 trf->chip_status_ctrl &= ~TRF7970A_CHIP_STATUS_RF_ON;
1136
1137 trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL, trf->chip_status_ctrl);
1138
1139 trf->aborting = false;
1140 trf->state = TRF7970A_ST_RF_OFF;
1141
1142 pm_runtime_mark_last_busy(trf->dev);
1143 pm_runtime_put_autosuspend(trf->dev);
1144 }
1145
trf7970a_switch_rf_on(struct trf7970a * trf)1146 static int trf7970a_switch_rf_on(struct trf7970a *trf)
1147 {
1148 int ret;
1149
1150 dev_dbg(trf->dev, "Switching rf on\n");
1151
1152 pm_runtime_get_sync(trf->dev);
1153
1154 if (trf->state != TRF7970A_ST_RF_OFF) { /* Power on, RF off */
1155 dev_err(trf->dev, "%s - Incorrect state: %d\n", __func__,
1156 trf->state);
1157 return -EINVAL;
1158 }
1159
1160 ret = trf7970a_init(trf);
1161 if (ret) {
1162 dev_err(trf->dev, "%s - Can't initialize: %d\n", __func__, ret);
1163 return ret;
1164 }
1165
1166 trf->state = TRF7970A_ST_IDLE;
1167
1168 return 0;
1169 }
1170
trf7970a_switch_rf(struct nfc_digital_dev * ddev,bool on)1171 static int trf7970a_switch_rf(struct nfc_digital_dev *ddev, bool on)
1172 {
1173 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1174 int ret = 0;
1175
1176 dev_dbg(trf->dev, "Switching RF - state: %d, on: %d\n", trf->state, on);
1177
1178 mutex_lock(&trf->lock);
1179
1180 if (on) {
1181 switch (trf->state) {
1182 case TRF7970A_ST_PWR_OFF:
1183 case TRF7970A_ST_RF_OFF:
1184 ret = trf7970a_switch_rf_on(trf);
1185 break;
1186 case TRF7970A_ST_IDLE:
1187 case TRF7970A_ST_IDLE_RX_BLOCKED:
1188 break;
1189 default:
1190 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1191 __func__, trf->state, on);
1192 trf7970a_switch_rf_off(trf);
1193 ret = -EINVAL;
1194 }
1195 } else {
1196 switch (trf->state) {
1197 case TRF7970A_ST_PWR_OFF:
1198 case TRF7970A_ST_RF_OFF:
1199 break;
1200 default:
1201 dev_err(trf->dev, "%s - Invalid request: %d %d\n",
1202 __func__, trf->state, on);
1203 ret = -EINVAL;
1204 fallthrough;
1205 case TRF7970A_ST_IDLE:
1206 case TRF7970A_ST_IDLE_RX_BLOCKED:
1207 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1208 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1209 trf7970a_switch_rf_off(trf);
1210 }
1211 }
1212
1213 mutex_unlock(&trf->lock);
1214 return ret;
1215 }
1216
trf7970a_in_config_rf_tech(struct trf7970a * trf,int tech)1217 static int trf7970a_in_config_rf_tech(struct trf7970a *trf, int tech)
1218 {
1219 int ret = 0;
1220
1221 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1222
1223 switch (tech) {
1224 case NFC_DIGITAL_RF_TECH_106A:
1225 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443A_106;
1226 trf->modulator_sys_clk_ctrl =
1227 (trf->modulator_sys_clk_ctrl & 0xf8) |
1228 TRF7970A_MODULATOR_DEPTH_OOK;
1229 trf->guard_time = TRF7970A_GUARD_TIME_NFCA;
1230 break;
1231 case NFC_DIGITAL_RF_TECH_106B:
1232 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_14443B_106;
1233 trf->modulator_sys_clk_ctrl =
1234 (trf->modulator_sys_clk_ctrl & 0xf8) |
1235 TRF7970A_MODULATOR_DEPTH_ASK10;
1236 trf->guard_time = TRF7970A_GUARD_TIME_NFCB;
1237 break;
1238 case NFC_DIGITAL_RF_TECH_212F:
1239 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_212;
1240 trf->modulator_sys_clk_ctrl =
1241 (trf->modulator_sys_clk_ctrl & 0xf8) |
1242 TRF7970A_MODULATOR_DEPTH_ASK10;
1243 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1244 break;
1245 case NFC_DIGITAL_RF_TECH_424F:
1246 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_FELICA_424;
1247 trf->modulator_sys_clk_ctrl =
1248 (trf->modulator_sys_clk_ctrl & 0xf8) |
1249 TRF7970A_MODULATOR_DEPTH_ASK10;
1250 trf->guard_time = TRF7970A_GUARD_TIME_NFCF;
1251 break;
1252 case NFC_DIGITAL_RF_TECH_ISO15693:
1253 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1254 trf->modulator_sys_clk_ctrl =
1255 (trf->modulator_sys_clk_ctrl & 0xf8) |
1256 TRF7970A_MODULATOR_DEPTH_OOK;
1257 trf->guard_time = TRF7970A_GUARD_TIME_15693;
1258 break;
1259 default:
1260 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1261 return -EINVAL;
1262 }
1263
1264 trf->technology = tech;
1265
1266 /* If in initiator mode and not changing the RF tech due to a
1267 * PSL sequence (indicated by 'trf->iso_ctrl == 0xff' from
1268 * trf7970a_init()), clear the NFC Target Detection Level register
1269 * due to erratum.
1270 */
1271 if (trf->iso_ctrl == 0xff)
1272 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
1273
1274 return ret;
1275 }
1276
trf7970a_is_rf_field(struct trf7970a * trf,bool * is_rf_field)1277 static int trf7970a_is_rf_field(struct trf7970a *trf, bool *is_rf_field)
1278 {
1279 int ret;
1280 u8 rssi;
1281
1282 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1283 trf->chip_status_ctrl |
1284 TRF7970A_CHIP_STATUS_REC_ON);
1285 if (ret)
1286 return ret;
1287
1288 ret = trf7970a_cmd(trf, TRF7970A_CMD_TEST_EXT_RF);
1289 if (ret)
1290 return ret;
1291
1292 usleep_range(50, 60);
1293
1294 ret = trf7970a_read(trf, TRF7970A_RSSI_OSC_STATUS, &rssi);
1295 if (ret)
1296 return ret;
1297
1298 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1299 trf->chip_status_ctrl);
1300 if (ret)
1301 return ret;
1302
1303 if (rssi & TRF7970A_RSSI_OSC_STATUS_RSSI_MASK)
1304 *is_rf_field = true;
1305 else
1306 *is_rf_field = false;
1307
1308 return 0;
1309 }
1310
trf7970a_in_config_framing(struct trf7970a * trf,int framing)1311 static int trf7970a_in_config_framing(struct trf7970a *trf, int framing)
1312 {
1313 u8 iso_ctrl = trf->iso_ctrl_tech;
1314 bool is_rf_field = false;
1315 int ret;
1316
1317 dev_dbg(trf->dev, "framing: %d\n", framing);
1318
1319 switch (framing) {
1320 case NFC_DIGITAL_FRAMING_NFCA_SHORT:
1321 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1322 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1323 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1324 break;
1325 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1326 case NFC_DIGITAL_FRAMING_NFCA_T4T:
1327 case NFC_DIGITAL_FRAMING_NFCB:
1328 case NFC_DIGITAL_FRAMING_NFCB_T4T:
1329 case NFC_DIGITAL_FRAMING_NFCF:
1330 case NFC_DIGITAL_FRAMING_NFCF_T3T:
1331 case NFC_DIGITAL_FRAMING_ISO15693_INVENTORY:
1332 case NFC_DIGITAL_FRAMING_ISO15693_T5T:
1333 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1334 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1335 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1336 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1337 break;
1338 case NFC_DIGITAL_FRAMING_NFCA_T2T:
1339 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1340 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1341 break;
1342 default:
1343 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1344 return -EINVAL;
1345 }
1346
1347 trf->framing = framing;
1348
1349 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1350 ret = trf7970a_is_rf_field(trf, &is_rf_field);
1351 if (ret)
1352 return ret;
1353
1354 if (is_rf_field)
1355 return -EBUSY;
1356 }
1357
1358 if (iso_ctrl != trf->iso_ctrl) {
1359 ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1360 if (ret)
1361 return ret;
1362
1363 trf->iso_ctrl = iso_ctrl;
1364
1365 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1366 trf->modulator_sys_clk_ctrl);
1367 if (ret)
1368 return ret;
1369 }
1370
1371 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1372 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1373 trf->chip_status_ctrl |
1374 TRF7970A_CHIP_STATUS_RF_ON);
1375 if (ret)
1376 return ret;
1377
1378 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1379
1380 usleep_range(trf->guard_time, trf->guard_time + 1000);
1381 }
1382
1383 return 0;
1384 }
1385
trf7970a_in_configure_hw(struct nfc_digital_dev * ddev,int type,int param)1386 static int trf7970a_in_configure_hw(struct nfc_digital_dev *ddev, int type,
1387 int param)
1388 {
1389 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1390 int ret;
1391
1392 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1393
1394 mutex_lock(&trf->lock);
1395
1396 trf->is_initiator = true;
1397
1398 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1399 (trf->state == TRF7970A_ST_RF_OFF)) {
1400 ret = trf7970a_switch_rf_on(trf);
1401 if (ret)
1402 goto err_unlock;
1403 }
1404
1405 switch (type) {
1406 case NFC_DIGITAL_CONFIG_RF_TECH:
1407 ret = trf7970a_in_config_rf_tech(trf, param);
1408 break;
1409 case NFC_DIGITAL_CONFIG_FRAMING:
1410 ret = trf7970a_in_config_framing(trf, param);
1411 break;
1412 default:
1413 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1414 ret = -EINVAL;
1415 }
1416
1417 err_unlock:
1418 mutex_unlock(&trf->lock);
1419 return ret;
1420 }
1421
trf7970a_is_iso15693_write_or_lock(u8 cmd)1422 static int trf7970a_is_iso15693_write_or_lock(u8 cmd)
1423 {
1424 switch (cmd) {
1425 case ISO15693_CMD_WRITE_SINGLE_BLOCK:
1426 case ISO15693_CMD_LOCK_BLOCK:
1427 case ISO15693_CMD_WRITE_MULTIPLE_BLOCK:
1428 case ISO15693_CMD_WRITE_AFI:
1429 case ISO15693_CMD_LOCK_AFI:
1430 case ISO15693_CMD_WRITE_DSFID:
1431 case ISO15693_CMD_LOCK_DSFID:
1432 return 1;
1433 default:
1434 return 0;
1435 }
1436 }
1437
trf7970a_per_cmd_config(struct trf7970a * trf,const struct sk_buff * skb)1438 static int trf7970a_per_cmd_config(struct trf7970a *trf,
1439 const struct sk_buff *skb)
1440 {
1441 const u8 *req = skb->data;
1442 u8 special_fcn_reg1, iso_ctrl;
1443 int ret;
1444
1445 trf->issue_eof = false;
1446
1447 /* When issuing Type 2 read command, make sure the '4_bit_RX' bit in
1448 * special functions register 1 is cleared; otherwise, its a write or
1449 * sector select command and '4_bit_RX' must be set.
1450 *
1451 * When issuing an ISO 15693 command, inspect the flags byte to see
1452 * what speed to use. Also, remember if the OPTION flag is set on
1453 * a Type 5 write or lock command so the driver will know that it
1454 * has to send an EOF in order to get a response.
1455 */
1456 if ((trf->technology == NFC_DIGITAL_RF_TECH_106A) &&
1457 (trf->framing == NFC_DIGITAL_FRAMING_NFCA_T2T)) {
1458 if (req[0] == NFC_T2T_CMD_READ)
1459 special_fcn_reg1 = 0;
1460 else
1461 special_fcn_reg1 = TRF7970A_SPECIAL_FCN_REG1_4_BIT_RX;
1462
1463 if (special_fcn_reg1 != trf->special_fcn_reg1) {
1464 ret = trf7970a_write(trf, TRF7970A_SPECIAL_FCN_REG1,
1465 special_fcn_reg1);
1466 if (ret)
1467 return ret;
1468
1469 trf->special_fcn_reg1 = special_fcn_reg1;
1470 }
1471 } else if (trf->technology == NFC_DIGITAL_RF_TECH_ISO15693) {
1472 iso_ctrl = trf->iso_ctrl & ~TRF7970A_ISO_CTRL_RFID_SPEED_MASK;
1473
1474 switch (req[0] & ISO15693_REQ_FLAG_SPEED_MASK) {
1475 case 0x00:
1476 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_662;
1477 break;
1478 case ISO15693_REQ_FLAG_SUB_CARRIER:
1479 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_667a;
1480 break;
1481 case ISO15693_REQ_FLAG_DATA_RATE:
1482 iso_ctrl |= TRF7970A_ISO_CTRL_15693_SGL_1OF4_2648;
1483 break;
1484 case (ISO15693_REQ_FLAG_SUB_CARRIER |
1485 ISO15693_REQ_FLAG_DATA_RATE):
1486 iso_ctrl |= TRF7970A_ISO_CTRL_15693_DBL_1OF4_2669;
1487 break;
1488 }
1489
1490 if (iso_ctrl != trf->iso_ctrl) {
1491 ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1492 if (ret)
1493 return ret;
1494
1495 trf->iso_ctrl = iso_ctrl;
1496 }
1497
1498 if ((trf->framing == NFC_DIGITAL_FRAMING_ISO15693_T5T) &&
1499 trf7970a_is_iso15693_write_or_lock(req[1]) &&
1500 (req[0] & ISO15693_REQ_FLAG_OPTION))
1501 trf->issue_eof = true;
1502 }
1503
1504 return 0;
1505 }
1506
trf7970a_send_cmd(struct nfc_digital_dev * ddev,struct sk_buff * skb,u16 timeout,nfc_digital_cmd_complete_t cb,void * arg)1507 static int trf7970a_send_cmd(struct nfc_digital_dev *ddev,
1508 struct sk_buff *skb, u16 timeout,
1509 nfc_digital_cmd_complete_t cb, void *arg)
1510 {
1511 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1512 u8 prefix[5];
1513 unsigned int len;
1514 int ret;
1515 u8 status;
1516
1517 dev_dbg(trf->dev, "New request - state: %d, timeout: %d ms, len: %d\n",
1518 trf->state, timeout, skb->len);
1519
1520 if (skb->len > TRF7970A_TX_MAX)
1521 return -EINVAL;
1522
1523 mutex_lock(&trf->lock);
1524
1525 if ((trf->state != TRF7970A_ST_IDLE) &&
1526 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1527 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1528 trf->state);
1529 ret = -EIO;
1530 goto out_err;
1531 }
1532
1533 if (trf->aborting) {
1534 dev_dbg(trf->dev, "Abort process complete\n");
1535 trf->aborting = false;
1536 ret = -ECANCELED;
1537 goto out_err;
1538 }
1539
1540 if (timeout) {
1541 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1542 GFP_KERNEL);
1543 if (!trf->rx_skb) {
1544 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1545 ret = -ENOMEM;
1546 goto out_err;
1547 }
1548 }
1549
1550 if (trf->state == TRF7970A_ST_IDLE_RX_BLOCKED) {
1551 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1552 if (ret)
1553 goto out_err;
1554
1555 trf->state = TRF7970A_ST_IDLE;
1556 }
1557
1558 if (trf->is_initiator) {
1559 ret = trf7970a_per_cmd_config(trf, skb);
1560 if (ret)
1561 goto out_err;
1562 }
1563
1564 trf->ddev = ddev;
1565 trf->tx_skb = skb;
1566 trf->cb = cb;
1567 trf->cb_arg = arg;
1568 trf->timeout = timeout;
1569 trf->ignore_timeout = false;
1570
1571 len = skb->len;
1572
1573 /* TX data must be prefixed with a FIFO reset cmd, a cmd that depends
1574 * on what the current framing is, the address of the TX length byte 1
1575 * register (0x1d), and the 2 byte length of the data to be transmitted.
1576 * That totals 5 bytes.
1577 */
1578 prefix[0] = TRF7970A_CMD_BIT_CTRL |
1579 TRF7970A_CMD_BIT_OPCODE(TRF7970A_CMD_FIFO_RESET);
1580 prefix[1] = TRF7970A_CMD_BIT_CTRL |
1581 TRF7970A_CMD_BIT_OPCODE(trf->tx_cmd);
1582 prefix[2] = TRF7970A_CMD_BIT_CONTINUOUS | TRF7970A_TX_LENGTH_BYTE1;
1583
1584 if (trf->framing == NFC_DIGITAL_FRAMING_NFCA_SHORT) {
1585 prefix[3] = 0x00;
1586 prefix[4] = 0x0f; /* 7 bits */
1587 } else {
1588 prefix[3] = (len & 0xf00) >> 4;
1589 prefix[3] |= ((len & 0xf0) >> 4);
1590 prefix[4] = ((len & 0x0f) << 4);
1591 }
1592
1593 len = min_t(int, skb->len, TRF7970A_FIFO_SIZE);
1594
1595 /* Clear possible spurious interrupt */
1596 ret = trf7970a_read_irqstatus(trf, &status);
1597 if (ret)
1598 goto out_err;
1599
1600 ret = trf7970a_transmit(trf, skb, len, prefix, sizeof(prefix));
1601 if (ret) {
1602 kfree_skb(trf->rx_skb);
1603 trf->rx_skb = NULL;
1604 }
1605
1606 out_err:
1607 mutex_unlock(&trf->lock);
1608 return ret;
1609 }
1610
trf7970a_tg_config_rf_tech(struct trf7970a * trf,int tech)1611 static int trf7970a_tg_config_rf_tech(struct trf7970a *trf, int tech)
1612 {
1613 int ret = 0;
1614
1615 dev_dbg(trf->dev, "rf technology: %d\n", tech);
1616
1617 switch (tech) {
1618 case NFC_DIGITAL_RF_TECH_106A:
1619 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1620 TRF7970A_ISO_CTRL_NFC_CE | TRF7970A_ISO_CTRL_NFC_CE_14443A;
1621 trf->modulator_sys_clk_ctrl =
1622 (trf->modulator_sys_clk_ctrl & 0xf8) |
1623 TRF7970A_MODULATOR_DEPTH_OOK;
1624 break;
1625 case NFC_DIGITAL_RF_TECH_212F:
1626 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1627 TRF7970A_ISO_CTRL_NFC_NFCF_212;
1628 trf->modulator_sys_clk_ctrl =
1629 (trf->modulator_sys_clk_ctrl & 0xf8) |
1630 TRF7970A_MODULATOR_DEPTH_ASK10;
1631 break;
1632 case NFC_DIGITAL_RF_TECH_424F:
1633 trf->iso_ctrl_tech = TRF7970A_ISO_CTRL_NFC_NFC_CE_MODE |
1634 TRF7970A_ISO_CTRL_NFC_NFCF_424;
1635 trf->modulator_sys_clk_ctrl =
1636 (trf->modulator_sys_clk_ctrl & 0xf8) |
1637 TRF7970A_MODULATOR_DEPTH_ASK10;
1638 break;
1639 default:
1640 dev_dbg(trf->dev, "Unsupported rf technology: %d\n", tech);
1641 return -EINVAL;
1642 }
1643
1644 trf->technology = tech;
1645
1646 /* Normally we write the ISO_CTRL register in
1647 * trf7970a_tg_config_framing() because the framing can change
1648 * the value written. However, when sending a PSL RES,
1649 * digital_tg_send_psl_res_complete() doesn't call
1650 * trf7970a_tg_config_framing() so we must write the register
1651 * here.
1652 */
1653 if ((trf->framing == NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED) &&
1654 (trf->iso_ctrl_tech != trf->iso_ctrl)) {
1655 ret = trf7970a_update_iso_ctrl_register(trf, trf->iso_ctrl_tech);
1656
1657 trf->iso_ctrl = trf->iso_ctrl_tech;
1658 }
1659
1660 return ret;
1661 }
1662
1663 /* Since this is a target routine, several of the framing calls are
1664 * made between receiving the request and sending the response so they
1665 * should take effect until after the response is sent. This is accomplished
1666 * by skipping the ISO_CTRL register write here and doing it in the interrupt
1667 * handler.
1668 */
trf7970a_tg_config_framing(struct trf7970a * trf,int framing)1669 static int trf7970a_tg_config_framing(struct trf7970a *trf, int framing)
1670 {
1671 u8 iso_ctrl = trf->iso_ctrl_tech;
1672 int ret;
1673
1674 dev_dbg(trf->dev, "framing: %d\n", framing);
1675
1676 switch (framing) {
1677 case NFC_DIGITAL_FRAMING_NFCA_NFC_DEP:
1678 trf->tx_cmd = TRF7970A_CMD_TRANSMIT_NO_CRC;
1679 iso_ctrl |= TRF7970A_ISO_CTRL_RX_CRC_N;
1680 break;
1681 case NFC_DIGITAL_FRAMING_NFCA_STANDARD:
1682 case NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A:
1683 case NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE:
1684 /* These ones are applied in the interrupt handler */
1685 iso_ctrl = trf->iso_ctrl; /* Don't write to ISO_CTRL yet */
1686 break;
1687 case NFC_DIGITAL_FRAMING_NFCF_NFC_DEP:
1688 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1689 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1690 break;
1691 case NFC_DIGITAL_FRAMING_NFC_DEP_ACTIVATED:
1692 trf->tx_cmd = TRF7970A_CMD_TRANSMIT;
1693 iso_ctrl &= ~TRF7970A_ISO_CTRL_RX_CRC_N;
1694 break;
1695 default:
1696 dev_dbg(trf->dev, "Unsupported Framing: %d\n", framing);
1697 return -EINVAL;
1698 }
1699
1700 trf->framing = framing;
1701
1702 if (iso_ctrl != trf->iso_ctrl) {
1703 ret = trf7970a_update_iso_ctrl_register(trf, iso_ctrl);
1704 if (ret)
1705 return ret;
1706
1707 trf->iso_ctrl = iso_ctrl;
1708
1709 ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL,
1710 trf->modulator_sys_clk_ctrl);
1711 if (ret)
1712 return ret;
1713 }
1714
1715 if (!(trf->chip_status_ctrl & TRF7970A_CHIP_STATUS_RF_ON)) {
1716 ret = trf7970a_write(trf, TRF7970A_CHIP_STATUS_CTRL,
1717 trf->chip_status_ctrl |
1718 TRF7970A_CHIP_STATUS_RF_ON);
1719 if (ret)
1720 return ret;
1721
1722 trf->chip_status_ctrl |= TRF7970A_CHIP_STATUS_RF_ON;
1723 }
1724
1725 return 0;
1726 }
1727
trf7970a_tg_configure_hw(struct nfc_digital_dev * ddev,int type,int param)1728 static int trf7970a_tg_configure_hw(struct nfc_digital_dev *ddev, int type,
1729 int param)
1730 {
1731 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1732 int ret;
1733
1734 dev_dbg(trf->dev, "Configure hw - type: %d, param: %d\n", type, param);
1735
1736 mutex_lock(&trf->lock);
1737
1738 trf->is_initiator = false;
1739
1740 if ((trf->state == TRF7970A_ST_PWR_OFF) ||
1741 (trf->state == TRF7970A_ST_RF_OFF)) {
1742 ret = trf7970a_switch_rf_on(trf);
1743 if (ret)
1744 goto err_unlock;
1745 }
1746
1747 switch (type) {
1748 case NFC_DIGITAL_CONFIG_RF_TECH:
1749 ret = trf7970a_tg_config_rf_tech(trf, param);
1750 break;
1751 case NFC_DIGITAL_CONFIG_FRAMING:
1752 ret = trf7970a_tg_config_framing(trf, param);
1753 break;
1754 default:
1755 dev_dbg(trf->dev, "Unknown type: %d\n", type);
1756 ret = -EINVAL;
1757 }
1758
1759 err_unlock:
1760 mutex_unlock(&trf->lock);
1761 return ret;
1762 }
1763
_trf7970a_tg_listen(struct nfc_digital_dev * ddev,u16 timeout,nfc_digital_cmd_complete_t cb,void * arg,bool mode_detect)1764 static int _trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1765 nfc_digital_cmd_complete_t cb, void *arg,
1766 bool mode_detect)
1767 {
1768 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1769 int ret;
1770
1771 mutex_lock(&trf->lock);
1772
1773 if ((trf->state != TRF7970A_ST_IDLE) &&
1774 (trf->state != TRF7970A_ST_IDLE_RX_BLOCKED)) {
1775 dev_err(trf->dev, "%s - Bogus state: %d\n", __func__,
1776 trf->state);
1777 ret = -EIO;
1778 goto out_err;
1779 }
1780
1781 if (trf->aborting) {
1782 dev_dbg(trf->dev, "Abort process complete\n");
1783 trf->aborting = false;
1784 ret = -ECANCELED;
1785 goto out_err;
1786 }
1787
1788 trf->rx_skb = nfc_alloc_recv_skb(TRF7970A_RX_SKB_ALLOC_SIZE,
1789 GFP_KERNEL);
1790 if (!trf->rx_skb) {
1791 dev_dbg(trf->dev, "Can't alloc rx_skb\n");
1792 ret = -ENOMEM;
1793 goto out_err;
1794 }
1795
1796 ret = trf7970a_write(trf, TRF7970A_RX_SPECIAL_SETTINGS,
1797 TRF7970A_RX_SPECIAL_SETTINGS_HBT |
1798 TRF7970A_RX_SPECIAL_SETTINGS_M848 |
1799 TRF7970A_RX_SPECIAL_SETTINGS_C424 |
1800 TRF7970A_RX_SPECIAL_SETTINGS_C212);
1801 if (ret)
1802 goto out_err;
1803
1804 ret = trf7970a_update_rx_gain_reduction(trf);
1805 if (ret)
1806 goto out_err;
1807
1808 ret = trf7970a_write(trf, TRF7970A_REG_IO_CTRL,
1809 trf->io_ctrl | TRF7970A_REG_IO_CTRL_VRS(0x1));
1810 if (ret)
1811 goto out_err;
1812
1813 ret = trf7970a_write(trf, TRF7970A_NFC_LOW_FIELD_LEVEL,
1814 TRF7970A_NFC_LOW_FIELD_LEVEL_RFDET(0x3));
1815 if (ret)
1816 goto out_err;
1817
1818 ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL,
1819 TRF7970A_NFC_TARGET_LEVEL_RFDET(0x7));
1820 if (ret)
1821 goto out_err;
1822
1823 trf->ddev = ddev;
1824 trf->cb = cb;
1825 trf->cb_arg = arg;
1826 trf->timeout = timeout;
1827 trf->ignore_timeout = false;
1828
1829 ret = trf7970a_cmd(trf, TRF7970A_CMD_ENABLE_RX);
1830 if (ret)
1831 goto out_err;
1832
1833 trf->state = mode_detect ? TRF7970A_ST_LISTENING_MD :
1834 TRF7970A_ST_LISTENING;
1835
1836 schedule_delayed_work(&trf->timeout_work, msecs_to_jiffies(timeout));
1837
1838 out_err:
1839 mutex_unlock(&trf->lock);
1840 return ret;
1841 }
1842
trf7970a_tg_listen(struct nfc_digital_dev * ddev,u16 timeout,nfc_digital_cmd_complete_t cb,void * arg)1843 static int trf7970a_tg_listen(struct nfc_digital_dev *ddev, u16 timeout,
1844 nfc_digital_cmd_complete_t cb, void *arg)
1845 {
1846 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1847
1848 dev_dbg(trf->dev, "Listen - state: %d, timeout: %d ms\n",
1849 trf->state, timeout);
1850
1851 return _trf7970a_tg_listen(ddev, timeout, cb, arg, false);
1852 }
1853
trf7970a_tg_listen_md(struct nfc_digital_dev * ddev,u16 timeout,nfc_digital_cmd_complete_t cb,void * arg)1854 static int trf7970a_tg_listen_md(struct nfc_digital_dev *ddev,
1855 u16 timeout, nfc_digital_cmd_complete_t cb,
1856 void *arg)
1857 {
1858 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1859 int ret;
1860
1861 dev_dbg(trf->dev, "Listen MD - state: %d, timeout: %d ms\n",
1862 trf->state, timeout);
1863
1864 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
1865 NFC_DIGITAL_RF_TECH_106A);
1866 if (ret)
1867 return ret;
1868
1869 ret = trf7970a_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
1870 NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
1871 if (ret)
1872 return ret;
1873
1874 return _trf7970a_tg_listen(ddev, timeout, cb, arg, true);
1875 }
1876
trf7970a_tg_get_rf_tech(struct nfc_digital_dev * ddev,u8 * rf_tech)1877 static int trf7970a_tg_get_rf_tech(struct nfc_digital_dev *ddev, u8 *rf_tech)
1878 {
1879 const struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1880
1881 dev_dbg(trf->dev, "Get RF Tech - state: %d, rf_tech: %d\n",
1882 trf->state, trf->md_rf_tech);
1883
1884 *rf_tech = trf->md_rf_tech;
1885
1886 return 0;
1887 }
1888
trf7970a_abort_cmd(struct nfc_digital_dev * ddev)1889 static void trf7970a_abort_cmd(struct nfc_digital_dev *ddev)
1890 {
1891 struct trf7970a *trf = nfc_digital_get_drvdata(ddev);
1892
1893 dev_dbg(trf->dev, "Abort process initiated\n");
1894
1895 mutex_lock(&trf->lock);
1896
1897 switch (trf->state) {
1898 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
1899 case TRF7970A_ST_WAIT_FOR_RX_DATA:
1900 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
1901 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
1902 trf->aborting = true;
1903 break;
1904 case TRF7970A_ST_LISTENING:
1905 trf->ignore_timeout = !cancel_delayed_work(&trf->timeout_work);
1906 trf7970a_send_err_upstream(trf, -ECANCELED);
1907 dev_dbg(trf->dev, "Abort process complete\n");
1908 break;
1909 default:
1910 break;
1911 }
1912
1913 mutex_unlock(&trf->lock);
1914 }
1915
1916 static const struct nfc_digital_ops trf7970a_nfc_ops = {
1917 .in_configure_hw = trf7970a_in_configure_hw,
1918 .in_send_cmd = trf7970a_send_cmd,
1919 .tg_configure_hw = trf7970a_tg_configure_hw,
1920 .tg_send_cmd = trf7970a_send_cmd,
1921 .tg_listen = trf7970a_tg_listen,
1922 .tg_listen_md = trf7970a_tg_listen_md,
1923 .tg_get_rf_tech = trf7970a_tg_get_rf_tech,
1924 .switch_rf = trf7970a_switch_rf,
1925 .abort_cmd = trf7970a_abort_cmd,
1926 };
1927
trf7970a_power_up(struct trf7970a * trf)1928 static int trf7970a_power_up(struct trf7970a *trf)
1929 {
1930 int ret;
1931
1932 dev_dbg(trf->dev, "Powering up - state: %d\n", trf->state);
1933
1934 if (trf->state != TRF7970A_ST_PWR_OFF)
1935 return 0;
1936
1937 ret = regulator_enable(trf->vin_regulator);
1938 if (ret) {
1939 dev_err(trf->dev, "%s - Can't enable VIN: %d\n", __func__, ret);
1940 return ret;
1941 }
1942
1943 usleep_range(5000, 6000);
1944
1945 if (trf->en2_gpiod &&
1946 !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW)) {
1947 gpiod_set_value_cansleep(trf->en2_gpiod, 1);
1948 usleep_range(1000, 2000);
1949 }
1950
1951 gpiod_set_value_cansleep(trf->en_gpiod, 1);
1952
1953 usleep_range(20000, 21000);
1954
1955 trf->state = TRF7970A_ST_RF_OFF;
1956
1957 return 0;
1958 }
1959
trf7970a_power_down(struct trf7970a * trf)1960 static int trf7970a_power_down(struct trf7970a *trf)
1961 {
1962 int ret;
1963
1964 dev_dbg(trf->dev, "Powering down - state: %d\n", trf->state);
1965
1966 if (trf->state == TRF7970A_ST_PWR_OFF)
1967 return 0;
1968
1969 if (trf->state != TRF7970A_ST_RF_OFF) {
1970 dev_dbg(trf->dev, "Can't power down - not RF_OFF state (%d)\n",
1971 trf->state);
1972 return -EBUSY;
1973 }
1974
1975 gpiod_set_value_cansleep(trf->en_gpiod, 0);
1976
1977 if (trf->en2_gpiod && !(trf->quirks & TRF7970A_QUIRK_EN2_MUST_STAY_LOW))
1978 gpiod_set_value_cansleep(trf->en2_gpiod, 0);
1979
1980 ret = regulator_disable(trf->vin_regulator);
1981 if (ret)
1982 dev_err(trf->dev, "%s - Can't disable VIN: %d\n", __func__,
1983 ret);
1984
1985 trf->state = TRF7970A_ST_PWR_OFF;
1986
1987 return ret;
1988 }
1989
trf7970a_startup(struct trf7970a * trf)1990 static int trf7970a_startup(struct trf7970a *trf)
1991 {
1992 int ret;
1993
1994 ret = trf7970a_power_up(trf);
1995 if (ret)
1996 return ret;
1997
1998 ret = trf7970a_update_rx_gain_reduction(trf);
1999 if (ret)
2000 return ret;
2001
2002 pm_runtime_set_active(trf->dev);
2003 pm_runtime_enable(trf->dev);
2004 pm_runtime_mark_last_busy(trf->dev);
2005
2006 return 0;
2007 }
2008
trf7970a_shutdown(struct trf7970a * trf)2009 static void trf7970a_shutdown(struct trf7970a *trf)
2010 {
2011 switch (trf->state) {
2012 case TRF7970A_ST_WAIT_FOR_TX_FIFO:
2013 case TRF7970A_ST_WAIT_FOR_RX_DATA:
2014 case TRF7970A_ST_WAIT_FOR_RX_DATA_CONT:
2015 case TRF7970A_ST_WAIT_TO_ISSUE_EOF:
2016 case TRF7970A_ST_LISTENING:
2017 trf7970a_send_err_upstream(trf, -ECANCELED);
2018 fallthrough;
2019 case TRF7970A_ST_IDLE:
2020 case TRF7970A_ST_IDLE_RX_BLOCKED:
2021 trf7970a_switch_rf_off(trf);
2022 break;
2023 default:
2024 break;
2025 }
2026
2027 pm_runtime_disable(trf->dev);
2028 pm_runtime_set_suspended(trf->dev);
2029
2030 trf7970a_power_down(trf);
2031 }
2032
trf7970a_get_autosuspend_delay(const struct device_node * np)2033 static int trf7970a_get_autosuspend_delay(const struct device_node *np)
2034 {
2035 int autosuspend_delay, ret;
2036
2037 ret = of_property_read_u32(np, "autosuspend-delay", &autosuspend_delay);
2038 if (ret)
2039 autosuspend_delay = TRF7970A_AUTOSUSPEND_DELAY;
2040
2041 return autosuspend_delay;
2042 }
2043
trf7970a_probe(struct spi_device * spi)2044 static int trf7970a_probe(struct spi_device *spi)
2045 {
2046 const struct device_node *np = spi->dev.of_node;
2047 struct trf7970a *trf;
2048 int uvolts, autosuspend_delay, ret;
2049 u32 clk_freq = TRF7970A_13MHZ_CLOCK_FREQUENCY;
2050 u32 rx_gain_reduction_db;
2051
2052 if (!np) {
2053 dev_err(&spi->dev, "No Device Tree entry\n");
2054 return -EINVAL;
2055 }
2056
2057 trf = devm_kzalloc(&spi->dev, sizeof(*trf), GFP_KERNEL);
2058 if (!trf)
2059 return -ENOMEM;
2060
2061 trf->state = TRF7970A_ST_PWR_OFF;
2062 trf->dev = &spi->dev;
2063 trf->spi = spi;
2064
2065 spi->mode = SPI_MODE_1;
2066 spi->bits_per_word = 8;
2067
2068 ret = spi_setup(spi);
2069 if (ret < 0) {
2070 dev_err(trf->dev, "Can't set up SPI Communication\n");
2071 return ret;
2072 }
2073
2074 if (of_property_read_bool(np, "irq-status-read-quirk"))
2075 trf->quirks |= TRF7970A_QUIRK_IRQ_STATUS_READ;
2076
2077 /* There are two enable pins - only EN must be present in the DT */
2078 trf->en_gpiod = devm_gpiod_get_index(trf->dev, "ti,enable", 0,
2079 GPIOD_OUT_LOW);
2080 if (IS_ERR(trf->en_gpiod)) {
2081 dev_err(trf->dev, "No EN GPIO property\n");
2082 return PTR_ERR(trf->en_gpiod);
2083 }
2084
2085 trf->en2_gpiod = devm_gpiod_get_index_optional(trf->dev, "ti,enable", 1,
2086 GPIOD_OUT_LOW);
2087 if (!trf->en2_gpiod) {
2088 dev_info(trf->dev, "No EN2 GPIO property\n");
2089 } else if (IS_ERR(trf->en2_gpiod)) {
2090 dev_err(trf->dev, "Error getting EN2 GPIO property: %ld\n",
2091 PTR_ERR(trf->en2_gpiod));
2092 return PTR_ERR(trf->en2_gpiod);
2093 } else if (of_property_read_bool(np, "en2-rf-quirk")) {
2094 trf->quirks |= TRF7970A_QUIRK_EN2_MUST_STAY_LOW;
2095 }
2096
2097 of_property_read_u32(np, "clock-frequency", &clk_freq);
2098 if ((clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) &&
2099 (clk_freq != TRF7970A_13MHZ_CLOCK_FREQUENCY)) {
2100 dev_err(trf->dev,
2101 "clock-frequency (%u Hz) unsupported\n", clk_freq);
2102 return -EINVAL;
2103 }
2104
2105 if (clk_freq == TRF7970A_27MHZ_CLOCK_FREQUENCY) {
2106 trf->modulator_sys_clk_ctrl = TRF7970A_MODULATOR_27MHZ;
2107 dev_dbg(trf->dev, "trf7970a configured for 27MHz crystal\n");
2108 } else {
2109 trf->modulator_sys_clk_ctrl = 0;
2110 }
2111
2112 if (of_property_read_u32(np, "ti,rx-gain-reduction-db", &rx_gain_reduction_db) == 0) {
2113 if (rx_gain_reduction_db > TRF7970A_RX_GAIN_REDUCTION_MAX_DB) {
2114 dev_warn(trf->dev, "RX Gain reduction too high. Ignored\n");
2115 } else if ((rx_gain_reduction_db % TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB)) {
2116 dev_warn(trf->dev, "RX Gain must be set in 5 dB increments. Ignored\n");
2117 } else {
2118 dev_dbg(trf->dev, "RX gain set to -%udB\n", rx_gain_reduction_db);
2119 trf->rx_gain_reduction = ((rx_gain_reduction_db /
2120 TRF7970A_RX_GAIN_REDUCTION_DB_PER_LSB) <<
2121 TRF7970A_RX_SPECIAL_SETTINGS_GD_SHIFT);
2122 trf->custom_rx_gain_reduction = true;
2123 }
2124 }
2125
2126 ret = devm_request_threaded_irq(trf->dev, spi->irq, NULL,
2127 trf7970a_irq,
2128 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
2129 "trf7970a", trf);
2130 if (ret) {
2131 dev_err(trf->dev, "Can't request IRQ#%d: %d\n", spi->irq, ret);
2132 return ret;
2133 }
2134
2135 mutex_init(&trf->lock);
2136 INIT_DELAYED_WORK(&trf->timeout_work, trf7970a_timeout_work_handler);
2137
2138 trf->vin_regulator = devm_regulator_get(&spi->dev, "vin");
2139 if (IS_ERR(trf->vin_regulator)) {
2140 ret = PTR_ERR(trf->vin_regulator);
2141 dev_err(trf->dev, "Can't get VIN regulator: %d\n", ret);
2142 goto err_destroy_lock;
2143 }
2144
2145 ret = regulator_enable(trf->vin_regulator);
2146 if (ret) {
2147 dev_err(trf->dev, "Can't enable VIN: %d\n", ret);
2148 goto err_destroy_lock;
2149 }
2150
2151 uvolts = regulator_get_voltage(trf->vin_regulator);
2152 if (uvolts > 4000000)
2153 trf->chip_status_ctrl = TRF7970A_CHIP_STATUS_VRS5_3;
2154
2155 trf->vddio_regulator = devm_regulator_get(&spi->dev, "vdd-io");
2156 if (IS_ERR(trf->vddio_regulator)) {
2157 ret = PTR_ERR(trf->vddio_regulator);
2158 dev_err(trf->dev, "Can't get VDD_IO regulator: %d\n", ret);
2159 goto err_disable_vin_regulator;
2160 }
2161
2162 ret = regulator_enable(trf->vddio_regulator);
2163 if (ret) {
2164 dev_err(trf->dev, "Can't enable VDD_IO: %d\n", ret);
2165 goto err_disable_vin_regulator;
2166 }
2167
2168 if (regulator_get_voltage(trf->vddio_regulator) == 1800000) {
2169 trf->io_ctrl = TRF7970A_REG_IO_CTRL_IO_LOW;
2170 dev_dbg(trf->dev, "trf7970a config vdd_io to 1.8V\n");
2171 }
2172
2173 trf->ddev = nfc_digital_allocate_device(&trf7970a_nfc_ops,
2174 TRF7970A_SUPPORTED_PROTOCOLS,
2175 NFC_DIGITAL_DRV_CAPS_IN_CRC |
2176 NFC_DIGITAL_DRV_CAPS_TG_CRC, 0,
2177 0);
2178 if (!trf->ddev) {
2179 dev_err(trf->dev, "Can't allocate NFC digital device\n");
2180 ret = -ENOMEM;
2181 goto err_disable_vddio_regulator;
2182 }
2183
2184 nfc_digital_set_parent_dev(trf->ddev, trf->dev);
2185 nfc_digital_set_drvdata(trf->ddev, trf);
2186 spi_set_drvdata(spi, trf);
2187
2188 autosuspend_delay = trf7970a_get_autosuspend_delay(np);
2189
2190 pm_runtime_set_autosuspend_delay(trf->dev, autosuspend_delay);
2191 pm_runtime_use_autosuspend(trf->dev);
2192
2193 ret = trf7970a_startup(trf);
2194 if (ret)
2195 goto err_free_ddev;
2196
2197 ret = nfc_digital_register_device(trf->ddev);
2198 if (ret) {
2199 dev_err(trf->dev, "Can't register NFC digital device: %d\n",
2200 ret);
2201 goto err_shutdown;
2202 }
2203
2204 return 0;
2205
2206 err_shutdown:
2207 trf7970a_shutdown(trf);
2208 err_free_ddev:
2209 nfc_digital_free_device(trf->ddev);
2210 err_disable_vddio_regulator:
2211 regulator_disable(trf->vddio_regulator);
2212 err_disable_vin_regulator:
2213 regulator_disable(trf->vin_regulator);
2214 err_destroy_lock:
2215 mutex_destroy(&trf->lock);
2216 return ret;
2217 }
2218
trf7970a_remove(struct spi_device * spi)2219 static void trf7970a_remove(struct spi_device *spi)
2220 {
2221 struct trf7970a *trf = spi_get_drvdata(spi);
2222
2223 mutex_lock(&trf->lock);
2224
2225 trf7970a_shutdown(trf);
2226
2227 mutex_unlock(&trf->lock);
2228
2229 nfc_digital_unregister_device(trf->ddev);
2230 nfc_digital_free_device(trf->ddev);
2231
2232 regulator_disable(trf->vddio_regulator);
2233 regulator_disable(trf->vin_regulator);
2234
2235 mutex_destroy(&trf->lock);
2236 }
2237
2238 #ifdef CONFIG_PM_SLEEP
trf7970a_suspend(struct device * dev)2239 static int trf7970a_suspend(struct device *dev)
2240 {
2241 struct spi_device *spi = to_spi_device(dev);
2242 struct trf7970a *trf = spi_get_drvdata(spi);
2243
2244 mutex_lock(&trf->lock);
2245
2246 trf7970a_shutdown(trf);
2247
2248 mutex_unlock(&trf->lock);
2249
2250 return 0;
2251 }
2252
trf7970a_resume(struct device * dev)2253 static int trf7970a_resume(struct device *dev)
2254 {
2255 struct spi_device *spi = to_spi_device(dev);
2256 struct trf7970a *trf = spi_get_drvdata(spi);
2257 int ret;
2258
2259 mutex_lock(&trf->lock);
2260
2261 ret = trf7970a_startup(trf);
2262
2263 mutex_unlock(&trf->lock);
2264
2265 return ret;
2266 }
2267 #endif
2268
2269 #ifdef CONFIG_PM
trf7970a_pm_runtime_suspend(struct device * dev)2270 static int trf7970a_pm_runtime_suspend(struct device *dev)
2271 {
2272 struct spi_device *spi = to_spi_device(dev);
2273 struct trf7970a *trf = spi_get_drvdata(spi);
2274 int ret;
2275
2276 mutex_lock(&trf->lock);
2277
2278 ret = trf7970a_power_down(trf);
2279
2280 mutex_unlock(&trf->lock);
2281
2282 return ret;
2283 }
2284
trf7970a_pm_runtime_resume(struct device * dev)2285 static int trf7970a_pm_runtime_resume(struct device *dev)
2286 {
2287 struct spi_device *spi = to_spi_device(dev);
2288 struct trf7970a *trf = spi_get_drvdata(spi);
2289 int ret;
2290
2291 ret = trf7970a_power_up(trf);
2292 if (!ret)
2293 pm_runtime_mark_last_busy(dev);
2294
2295 return ret;
2296 }
2297 #endif
2298
2299 static const struct dev_pm_ops trf7970a_pm_ops = {
2300 SET_SYSTEM_SLEEP_PM_OPS(trf7970a_suspend, trf7970a_resume)
2301 SET_RUNTIME_PM_OPS(trf7970a_pm_runtime_suspend,
2302 trf7970a_pm_runtime_resume, NULL)
2303 };
2304
2305 static const struct of_device_id trf7970a_of_match[] __maybe_unused = {
2306 {.compatible = "ti,trf7970a",},
2307 {},
2308 };
2309
2310 MODULE_DEVICE_TABLE(of, trf7970a_of_match);
2311
2312 static const struct spi_device_id trf7970a_id_table[] = {
2313 {"trf7970a", 0},
2314 {}
2315 };
2316
2317 MODULE_DEVICE_TABLE(spi, trf7970a_id_table);
2318
2319 static struct spi_driver trf7970a_spi_driver = {
2320 .probe = trf7970a_probe,
2321 .remove = trf7970a_remove,
2322 .id_table = trf7970a_id_table,
2323 .driver = {
2324 .name = "trf7970a",
2325 .of_match_table = of_match_ptr(trf7970a_of_match),
2326 .pm = &trf7970a_pm_ops,
2327 },
2328 };
2329
2330 module_spi_driver(trf7970a_spi_driver);
2331
2332 MODULE_AUTHOR("Mark A. Greer <mgreer@animalcreek.com>");
2333 MODULE_LICENSE("GPL v2");
2334 MODULE_DESCRIPTION("TI trf7970a RFID/NFC Transceiver Driver");
2335