xref: /openbmc/linux/drivers/net/can/rcar/rcar_canfd.c (revision de3a9980)
1 // SPDX-License-Identifier: GPL-2.0+
2 /* Renesas R-Car CAN FD device driver
3  *
4  * Copyright (C) 2015 Renesas Electronics Corp.
5  */
6 
7 /* The R-Car CAN FD controller can operate in either one of the below two modes
8  *  - CAN FD only mode
9  *  - Classical CAN (CAN 2.0) only mode
10  *
11  * This driver puts the controller in CAN FD only mode by default. In this
12  * mode, the controller acts as a CAN FD node that can also interoperate with
13  * CAN 2.0 nodes.
14  *
15  * To switch the controller to Classical CAN (CAN 2.0) only mode, add
16  * "renesas,no-can-fd" optional property to the device tree node. A h/w reset is
17  * also required to switch modes.
18  *
19  * Note: The h/w manual register naming convention is clumsy and not acceptable
20  * to use as it is in the driver. However, those names are added as comments
21  * wherever it is modified to a readable name.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/kernel.h>
27 #include <linux/types.h>
28 #include <linux/interrupt.h>
29 #include <linux/errno.h>
30 #include <linux/netdevice.h>
31 #include <linux/platform_device.h>
32 #include <linux/can/led.h>
33 #include <linux/can/dev.h>
34 #include <linux/clk.h>
35 #include <linux/of.h>
36 #include <linux/of_device.h>
37 #include <linux/bitmap.h>
38 #include <linux/bitops.h>
39 #include <linux/iopoll.h>
40 
41 #define RCANFD_DRV_NAME			"rcar_canfd"
42 
43 /* Global register bits */
44 
45 /* RSCFDnCFDGRMCFG */
46 #define RCANFD_GRMCFG_RCMC		BIT(0)
47 
48 /* RSCFDnCFDGCFG / RSCFDnGCFG */
49 #define RCANFD_GCFG_EEFE		BIT(6)
50 #define RCANFD_GCFG_CMPOC		BIT(5)	/* CAN FD only */
51 #define RCANFD_GCFG_DCS			BIT(4)
52 #define RCANFD_GCFG_DCE			BIT(1)
53 #define RCANFD_GCFG_TPRI		BIT(0)
54 
55 /* RSCFDnCFDGCTR / RSCFDnGCTR */
56 #define RCANFD_GCTR_TSRST		BIT(16)
57 #define RCANFD_GCTR_CFMPOFIE		BIT(11)	/* CAN FD only */
58 #define RCANFD_GCTR_THLEIE		BIT(10)
59 #define RCANFD_GCTR_MEIE		BIT(9)
60 #define RCANFD_GCTR_DEIE		BIT(8)
61 #define RCANFD_GCTR_GSLPR		BIT(2)
62 #define RCANFD_GCTR_GMDC_MASK		(0x3)
63 #define RCANFD_GCTR_GMDC_GOPM		(0x0)
64 #define RCANFD_GCTR_GMDC_GRESET		(0x1)
65 #define RCANFD_GCTR_GMDC_GTEST		(0x2)
66 
67 /* RSCFDnCFDGSTS / RSCFDnGSTS */
68 #define RCANFD_GSTS_GRAMINIT		BIT(3)
69 #define RCANFD_GSTS_GSLPSTS		BIT(2)
70 #define RCANFD_GSTS_GHLTSTS		BIT(1)
71 #define RCANFD_GSTS_GRSTSTS		BIT(0)
72 /* Non-operational status */
73 #define RCANFD_GSTS_GNOPM		(BIT(0) | BIT(1) | BIT(2) | BIT(3))
74 
75 /* RSCFDnCFDGERFL / RSCFDnGERFL */
76 #define RCANFD_GERFL_EEF1		BIT(17)
77 #define RCANFD_GERFL_EEF0		BIT(16)
78 #define RCANFD_GERFL_CMPOF		BIT(3)	/* CAN FD only */
79 #define RCANFD_GERFL_THLES		BIT(2)
80 #define RCANFD_GERFL_MES		BIT(1)
81 #define RCANFD_GERFL_DEF		BIT(0)
82 
83 #define RCANFD_GERFL_ERR(gpriv, x)	((x) & (RCANFD_GERFL_EEF1 |\
84 					RCANFD_GERFL_EEF0 | RCANFD_GERFL_MES |\
85 					(gpriv->fdmode ?\
86 					 RCANFD_GERFL_CMPOF : 0)))
87 
88 /* AFL Rx rules registers */
89 
90 /* RSCFDnCFDGAFLCFG0 / RSCFDnGAFLCFG0 */
91 #define RCANFD_GAFLCFG_SETRNC(n, x)	(((x) & 0xff) << (24 - n * 8))
92 #define RCANFD_GAFLCFG_GETRNC(n, x)	(((x) >> (24 - n * 8)) & 0xff)
93 
94 /* RSCFDnCFDGAFLECTR / RSCFDnGAFLECTR */
95 #define RCANFD_GAFLECTR_AFLDAE		BIT(8)
96 #define RCANFD_GAFLECTR_AFLPN(x)	((x) & 0x1f)
97 
98 /* RSCFDnCFDGAFLIDj / RSCFDnGAFLIDj */
99 #define RCANFD_GAFLID_GAFLLB		BIT(29)
100 
101 /* RSCFDnCFDGAFLP1_j / RSCFDnGAFLP1_j */
102 #define RCANFD_GAFLP1_GAFLFDP(x)	(1 << (x))
103 
104 /* Channel register bits */
105 
106 /* RSCFDnCmCFG - Classical CAN only */
107 #define RCANFD_CFG_SJW(x)		(((x) & 0x3) << 24)
108 #define RCANFD_CFG_TSEG2(x)		(((x) & 0x7) << 20)
109 #define RCANFD_CFG_TSEG1(x)		(((x) & 0xf) << 16)
110 #define RCANFD_CFG_BRP(x)		(((x) & 0x3ff) << 0)
111 
112 /* RSCFDnCFDCmNCFG - CAN FD only */
113 #define RCANFD_NCFG_NTSEG2(x)		(((x) & 0x1f) << 24)
114 #define RCANFD_NCFG_NTSEG1(x)		(((x) & 0x7f) << 16)
115 #define RCANFD_NCFG_NSJW(x)		(((x) & 0x1f) << 11)
116 #define RCANFD_NCFG_NBRP(x)		(((x) & 0x3ff) << 0)
117 
118 /* RSCFDnCFDCmCTR / RSCFDnCmCTR */
119 #define RCANFD_CCTR_CTME		BIT(24)
120 #define RCANFD_CCTR_ERRD		BIT(23)
121 #define RCANFD_CCTR_BOM_MASK		(0x3 << 21)
122 #define RCANFD_CCTR_BOM_ISO		(0x0 << 21)
123 #define RCANFD_CCTR_BOM_BENTRY		(0x1 << 21)
124 #define RCANFD_CCTR_BOM_BEND		(0x2 << 21)
125 #define RCANFD_CCTR_TDCVFIE		BIT(19)
126 #define RCANFD_CCTR_SOCOIE		BIT(18)
127 #define RCANFD_CCTR_EOCOIE		BIT(17)
128 #define RCANFD_CCTR_TAIE		BIT(16)
129 #define RCANFD_CCTR_ALIE		BIT(15)
130 #define RCANFD_CCTR_BLIE		BIT(14)
131 #define RCANFD_CCTR_OLIE		BIT(13)
132 #define RCANFD_CCTR_BORIE		BIT(12)
133 #define RCANFD_CCTR_BOEIE		BIT(11)
134 #define RCANFD_CCTR_EPIE		BIT(10)
135 #define RCANFD_CCTR_EWIE		BIT(9)
136 #define RCANFD_CCTR_BEIE		BIT(8)
137 #define RCANFD_CCTR_CSLPR		BIT(2)
138 #define RCANFD_CCTR_CHMDC_MASK		(0x3)
139 #define RCANFD_CCTR_CHDMC_COPM		(0x0)
140 #define RCANFD_CCTR_CHDMC_CRESET	(0x1)
141 #define RCANFD_CCTR_CHDMC_CHLT		(0x2)
142 
143 /* RSCFDnCFDCmSTS / RSCFDnCmSTS */
144 #define RCANFD_CSTS_COMSTS		BIT(7)
145 #define RCANFD_CSTS_RECSTS		BIT(6)
146 #define RCANFD_CSTS_TRMSTS		BIT(5)
147 #define RCANFD_CSTS_BOSTS		BIT(4)
148 #define RCANFD_CSTS_EPSTS		BIT(3)
149 #define RCANFD_CSTS_SLPSTS		BIT(2)
150 #define RCANFD_CSTS_HLTSTS		BIT(1)
151 #define RCANFD_CSTS_CRSTSTS		BIT(0)
152 
153 #define RCANFD_CSTS_TECCNT(x)		(((x) >> 24) & 0xff)
154 #define RCANFD_CSTS_RECCNT(x)		(((x) >> 16) & 0xff)
155 
156 /* RSCFDnCFDCmERFL / RSCFDnCmERFL */
157 #define RCANFD_CERFL_ADERR		BIT(14)
158 #define RCANFD_CERFL_B0ERR		BIT(13)
159 #define RCANFD_CERFL_B1ERR		BIT(12)
160 #define RCANFD_CERFL_CERR		BIT(11)
161 #define RCANFD_CERFL_AERR		BIT(10)
162 #define RCANFD_CERFL_FERR		BIT(9)
163 #define RCANFD_CERFL_SERR		BIT(8)
164 #define RCANFD_CERFL_ALF		BIT(7)
165 #define RCANFD_CERFL_BLF		BIT(6)
166 #define RCANFD_CERFL_OVLF		BIT(5)
167 #define RCANFD_CERFL_BORF		BIT(4)
168 #define RCANFD_CERFL_BOEF		BIT(3)
169 #define RCANFD_CERFL_EPF		BIT(2)
170 #define RCANFD_CERFL_EWF		BIT(1)
171 #define RCANFD_CERFL_BEF		BIT(0)
172 
173 #define RCANFD_CERFL_ERR(x)		((x) & (0x7fff)) /* above bits 14:0 */
174 
175 /* RSCFDnCFDCmDCFG */
176 #define RCANFD_DCFG_DSJW(x)		(((x) & 0x7) << 24)
177 #define RCANFD_DCFG_DTSEG2(x)		(((x) & 0x7) << 20)
178 #define RCANFD_DCFG_DTSEG1(x)		(((x) & 0xf) << 16)
179 #define RCANFD_DCFG_DBRP(x)		(((x) & 0xff) << 0)
180 
181 /* RSCFDnCFDCmFDCFG */
182 #define RCANFD_FDCFG_TDCE		BIT(9)
183 #define RCANFD_FDCFG_TDCOC		BIT(8)
184 #define RCANFD_FDCFG_TDCO(x)		(((x) & 0x7f) >> 16)
185 
186 /* RSCFDnCFDRFCCx */
187 #define RCANFD_RFCC_RFIM		BIT(12)
188 #define RCANFD_RFCC_RFDC(x)		(((x) & 0x7) << 8)
189 #define RCANFD_RFCC_RFPLS(x)		(((x) & 0x7) << 4)
190 #define RCANFD_RFCC_RFIE		BIT(1)
191 #define RCANFD_RFCC_RFE			BIT(0)
192 
193 /* RSCFDnCFDRFSTSx */
194 #define RCANFD_RFSTS_RFIF		BIT(3)
195 #define RCANFD_RFSTS_RFMLT		BIT(2)
196 #define RCANFD_RFSTS_RFFLL		BIT(1)
197 #define RCANFD_RFSTS_RFEMP		BIT(0)
198 
199 /* RSCFDnCFDRFIDx */
200 #define RCANFD_RFID_RFIDE		BIT(31)
201 #define RCANFD_RFID_RFRTR		BIT(30)
202 
203 /* RSCFDnCFDRFPTRx */
204 #define RCANFD_RFPTR_RFDLC(x)		(((x) >> 28) & 0xf)
205 #define RCANFD_RFPTR_RFPTR(x)		(((x) >> 16) & 0xfff)
206 #define RCANFD_RFPTR_RFTS(x)		(((x) >> 0) & 0xffff)
207 
208 /* RSCFDnCFDRFFDSTSx */
209 #define RCANFD_RFFDSTS_RFFDF		BIT(2)
210 #define RCANFD_RFFDSTS_RFBRS		BIT(1)
211 #define RCANFD_RFFDSTS_RFESI		BIT(0)
212 
213 /* Common FIFO bits */
214 
215 /* RSCFDnCFDCFCCk */
216 #define RCANFD_CFCC_CFTML(x)		(((x) & 0xf) << 20)
217 #define RCANFD_CFCC_CFM(x)		(((x) & 0x3) << 16)
218 #define RCANFD_CFCC_CFIM		BIT(12)
219 #define RCANFD_CFCC_CFDC(x)		(((x) & 0x7) << 8)
220 #define RCANFD_CFCC_CFPLS(x)		(((x) & 0x7) << 4)
221 #define RCANFD_CFCC_CFTXIE		BIT(2)
222 #define RCANFD_CFCC_CFE			BIT(0)
223 
224 /* RSCFDnCFDCFSTSk */
225 #define RCANFD_CFSTS_CFMC(x)		(((x) >> 8) & 0xff)
226 #define RCANFD_CFSTS_CFTXIF		BIT(4)
227 #define RCANFD_CFSTS_CFMLT		BIT(2)
228 #define RCANFD_CFSTS_CFFLL		BIT(1)
229 #define RCANFD_CFSTS_CFEMP		BIT(0)
230 
231 /* RSCFDnCFDCFIDk */
232 #define RCANFD_CFID_CFIDE		BIT(31)
233 #define RCANFD_CFID_CFRTR		BIT(30)
234 #define RCANFD_CFID_CFID_MASK(x)	((x) & 0x1fffffff)
235 
236 /* RSCFDnCFDCFPTRk */
237 #define RCANFD_CFPTR_CFDLC(x)		(((x) & 0xf) << 28)
238 #define RCANFD_CFPTR_CFPTR(x)		(((x) & 0xfff) << 16)
239 #define RCANFD_CFPTR_CFTS(x)		(((x) & 0xff) << 0)
240 
241 /* RSCFDnCFDCFFDCSTSk */
242 #define RCANFD_CFFDCSTS_CFFDF		BIT(2)
243 #define RCANFD_CFFDCSTS_CFBRS		BIT(1)
244 #define RCANFD_CFFDCSTS_CFESI		BIT(0)
245 
246 /* This controller supports either Classical CAN only mode or CAN FD only mode.
247  * These modes are supported in two separate set of register maps & names.
248  * However, some of the register offsets are common for both modes. Those
249  * offsets are listed below as Common registers.
250  *
251  * The CAN FD only mode specific registers & Classical CAN only mode specific
252  * registers are listed separately. Their register names starts with
253  * RCANFD_F_xxx & RCANFD_C_xxx respectively.
254  */
255 
256 /* Common registers */
257 
258 /* RSCFDnCFDCmNCFG / RSCFDnCmCFG */
259 #define RCANFD_CCFG(m)			(0x0000 + (0x10 * (m)))
260 /* RSCFDnCFDCmCTR / RSCFDnCmCTR */
261 #define RCANFD_CCTR(m)			(0x0004 + (0x10 * (m)))
262 /* RSCFDnCFDCmSTS / RSCFDnCmSTS */
263 #define RCANFD_CSTS(m)			(0x0008 + (0x10 * (m)))
264 /* RSCFDnCFDCmERFL / RSCFDnCmERFL */
265 #define RCANFD_CERFL(m)			(0x000C + (0x10 * (m)))
266 
267 /* RSCFDnCFDGCFG / RSCFDnGCFG */
268 #define RCANFD_GCFG			(0x0084)
269 /* RSCFDnCFDGCTR / RSCFDnGCTR */
270 #define RCANFD_GCTR			(0x0088)
271 /* RSCFDnCFDGCTS / RSCFDnGCTS */
272 #define RCANFD_GSTS			(0x008c)
273 /* RSCFDnCFDGERFL / RSCFDnGERFL */
274 #define RCANFD_GERFL			(0x0090)
275 /* RSCFDnCFDGTSC / RSCFDnGTSC */
276 #define RCANFD_GTSC			(0x0094)
277 /* RSCFDnCFDGAFLECTR / RSCFDnGAFLECTR */
278 #define RCANFD_GAFLECTR			(0x0098)
279 /* RSCFDnCFDGAFLCFG0 / RSCFDnGAFLCFG0 */
280 #define RCANFD_GAFLCFG0			(0x009c)
281 /* RSCFDnCFDGAFLCFG1 / RSCFDnGAFLCFG1 */
282 #define RCANFD_GAFLCFG1			(0x00a0)
283 /* RSCFDnCFDRMNB / RSCFDnRMNB */
284 #define RCANFD_RMNB			(0x00a4)
285 /* RSCFDnCFDRMND / RSCFDnRMND */
286 #define RCANFD_RMND(y)			(0x00a8 + (0x04 * (y)))
287 
288 /* RSCFDnCFDRFCCx / RSCFDnRFCCx */
289 #define RCANFD_RFCC(x)			(0x00b8 + (0x04 * (x)))
290 /* RSCFDnCFDRFSTSx / RSCFDnRFSTSx */
291 #define RCANFD_RFSTS(x)			(0x00d8 + (0x04 * (x)))
292 /* RSCFDnCFDRFPCTRx / RSCFDnRFPCTRx */
293 #define RCANFD_RFPCTR(x)		(0x00f8 + (0x04 * (x)))
294 
295 /* Common FIFO Control registers */
296 
297 /* RSCFDnCFDCFCCx / RSCFDnCFCCx */
298 #define RCANFD_CFCC(ch, idx)		(0x0118 + (0x0c * (ch)) + \
299 					 (0x04 * (idx)))
300 /* RSCFDnCFDCFSTSx / RSCFDnCFSTSx */
301 #define RCANFD_CFSTS(ch, idx)		(0x0178 + (0x0c * (ch)) + \
302 					 (0x04 * (idx)))
303 /* RSCFDnCFDCFPCTRx / RSCFDnCFPCTRx */
304 #define RCANFD_CFPCTR(ch, idx)		(0x01d8 + (0x0c * (ch)) + \
305 					 (0x04 * (idx)))
306 
307 /* RSCFDnCFDFESTS / RSCFDnFESTS */
308 #define RCANFD_FESTS			(0x0238)
309 /* RSCFDnCFDFFSTS / RSCFDnFFSTS */
310 #define RCANFD_FFSTS			(0x023c)
311 /* RSCFDnCFDFMSTS / RSCFDnFMSTS */
312 #define RCANFD_FMSTS			(0x0240)
313 /* RSCFDnCFDRFISTS / RSCFDnRFISTS */
314 #define RCANFD_RFISTS			(0x0244)
315 /* RSCFDnCFDCFRISTS / RSCFDnCFRISTS */
316 #define RCANFD_CFRISTS			(0x0248)
317 /* RSCFDnCFDCFTISTS / RSCFDnCFTISTS */
318 #define RCANFD_CFTISTS			(0x024c)
319 
320 /* RSCFDnCFDTMCp / RSCFDnTMCp */
321 #define RCANFD_TMC(p)			(0x0250 + (0x01 * (p)))
322 /* RSCFDnCFDTMSTSp / RSCFDnTMSTSp */
323 #define RCANFD_TMSTS(p)			(0x02d0 + (0x01 * (p)))
324 
325 /* RSCFDnCFDTMTRSTSp / RSCFDnTMTRSTSp */
326 #define RCANFD_TMTRSTS(y)		(0x0350 + (0x04 * (y)))
327 /* RSCFDnCFDTMTARSTSp / RSCFDnTMTARSTSp */
328 #define RCANFD_TMTARSTS(y)		(0x0360 + (0x04 * (y)))
329 /* RSCFDnCFDTMTCSTSp / RSCFDnTMTCSTSp */
330 #define RCANFD_TMTCSTS(y)		(0x0370 + (0x04 * (y)))
331 /* RSCFDnCFDTMTASTSp / RSCFDnTMTASTSp */
332 #define RCANFD_TMTASTS(y)		(0x0380 + (0x04 * (y)))
333 /* RSCFDnCFDTMIECy / RSCFDnTMIECy */
334 #define RCANFD_TMIEC(y)			(0x0390 + (0x04 * (y)))
335 
336 /* RSCFDnCFDTXQCCm / RSCFDnTXQCCm */
337 #define RCANFD_TXQCC(m)			(0x03a0 + (0x04 * (m)))
338 /* RSCFDnCFDTXQSTSm / RSCFDnTXQSTSm */
339 #define RCANFD_TXQSTS(m)		(0x03c0 + (0x04 * (m)))
340 /* RSCFDnCFDTXQPCTRm / RSCFDnTXQPCTRm */
341 #define RCANFD_TXQPCTR(m)		(0x03e0 + (0x04 * (m)))
342 
343 /* RSCFDnCFDTHLCCm / RSCFDnTHLCCm */
344 #define RCANFD_THLCC(m)			(0x0400 + (0x04 * (m)))
345 /* RSCFDnCFDTHLSTSm / RSCFDnTHLSTSm */
346 #define RCANFD_THLSTS(m)		(0x0420 + (0x04 * (m)))
347 /* RSCFDnCFDTHLPCTRm / RSCFDnTHLPCTRm */
348 #define RCANFD_THLPCTR(m)		(0x0440 + (0x04 * (m)))
349 
350 /* RSCFDnCFDGTINTSTS0 / RSCFDnGTINTSTS0 */
351 #define RCANFD_GTINTSTS0		(0x0460)
352 /* RSCFDnCFDGTINTSTS1 / RSCFDnGTINTSTS1 */
353 #define RCANFD_GTINTSTS1		(0x0464)
354 /* RSCFDnCFDGTSTCFG / RSCFDnGTSTCFG */
355 #define RCANFD_GTSTCFG			(0x0468)
356 /* RSCFDnCFDGTSTCTR / RSCFDnGTSTCTR */
357 #define RCANFD_GTSTCTR			(0x046c)
358 /* RSCFDnCFDGLOCKK / RSCFDnGLOCKK */
359 #define RCANFD_GLOCKK			(0x047c)
360 /* RSCFDnCFDGRMCFG */
361 #define RCANFD_GRMCFG			(0x04fc)
362 
363 /* RSCFDnCFDGAFLIDj / RSCFDnGAFLIDj */
364 #define RCANFD_GAFLID(offset, j)	((offset) + (0x10 * (j)))
365 /* RSCFDnCFDGAFLMj / RSCFDnGAFLMj */
366 #define RCANFD_GAFLM(offset, j)		((offset) + 0x04 + (0x10 * (j)))
367 /* RSCFDnCFDGAFLP0j / RSCFDnGAFLP0j */
368 #define RCANFD_GAFLP0(offset, j)	((offset) + 0x08 + (0x10 * (j)))
369 /* RSCFDnCFDGAFLP1j / RSCFDnGAFLP1j */
370 #define RCANFD_GAFLP1(offset, j)	((offset) + 0x0c + (0x10 * (j)))
371 
372 /* Classical CAN only mode register map */
373 
374 /* RSCFDnGAFLXXXj offset */
375 #define RCANFD_C_GAFL_OFFSET		(0x0500)
376 
377 /* RSCFDnRMXXXq -> RCANFD_C_RMXXX(q) */
378 #define RCANFD_C_RMID(q)		(0x0600 + (0x10 * (q)))
379 #define RCANFD_C_RMPTR(q)		(0x0604 + (0x10 * (q)))
380 #define RCANFD_C_RMDF0(q)		(0x0608 + (0x10 * (q)))
381 #define RCANFD_C_RMDF1(q)		(0x060c + (0x10 * (q)))
382 
383 /* RSCFDnRFXXx -> RCANFD_C_RFXX(x) */
384 #define RCANFD_C_RFOFFSET		(0x0e00)
385 #define RCANFD_C_RFID(x)		(RCANFD_C_RFOFFSET + (0x10 * (x)))
386 #define RCANFD_C_RFPTR(x)		(RCANFD_C_RFOFFSET + 0x04 + \
387 					 (0x10 * (x)))
388 #define RCANFD_C_RFDF(x, df)		(RCANFD_C_RFOFFSET + 0x08 + \
389 					 (0x10 * (x)) + (0x04 * (df)))
390 
391 /* RSCFDnCFXXk -> RCANFD_C_CFXX(ch, k) */
392 #define RCANFD_C_CFOFFSET		(0x0e80)
393 #define RCANFD_C_CFID(ch, idx)		(RCANFD_C_CFOFFSET + (0x30 * (ch)) + \
394 					 (0x10 * (idx)))
395 #define RCANFD_C_CFPTR(ch, idx)		(RCANFD_C_CFOFFSET + 0x04 + \
396 					 (0x30 * (ch)) + (0x10 * (idx)))
397 #define RCANFD_C_CFDF(ch, idx, df)	(RCANFD_C_CFOFFSET + 0x08 + \
398 					 (0x30 * (ch)) + (0x10 * (idx)) + \
399 					 (0x04 * (df)))
400 
401 /* RSCFDnTMXXp -> RCANFD_C_TMXX(p) */
402 #define RCANFD_C_TMID(p)		(0x1000 + (0x10 * (p)))
403 #define RCANFD_C_TMPTR(p)		(0x1004 + (0x10 * (p)))
404 #define RCANFD_C_TMDF0(p)		(0x1008 + (0x10 * (p)))
405 #define RCANFD_C_TMDF1(p)		(0x100c + (0x10 * (p)))
406 
407 /* RSCFDnTHLACCm */
408 #define RCANFD_C_THLACC(m)		(0x1800 + (0x04 * (m)))
409 /* RSCFDnRPGACCr */
410 #define RCANFD_C_RPGACC(r)		(0x1900 + (0x04 * (r)))
411 
412 /* CAN FD mode specific register map */
413 
414 /* RSCFDnCFDCmXXX -> RCANFD_F_XXX(m) */
415 #define RCANFD_F_DCFG(m)		(0x0500 + (0x20 * (m)))
416 #define RCANFD_F_CFDCFG(m)		(0x0504 + (0x20 * (m)))
417 #define RCANFD_F_CFDCTR(m)		(0x0508 + (0x20 * (m)))
418 #define RCANFD_F_CFDSTS(m)		(0x050c + (0x20 * (m)))
419 #define RCANFD_F_CFDCRC(m)		(0x0510 + (0x20 * (m)))
420 
421 /* RSCFDnCFDGAFLXXXj offset */
422 #define RCANFD_F_GAFL_OFFSET		(0x1000)
423 
424 /* RSCFDnCFDRMXXXq -> RCANFD_F_RMXXX(q) */
425 #define RCANFD_F_RMID(q)		(0x2000 + (0x20 * (q)))
426 #define RCANFD_F_RMPTR(q)		(0x2004 + (0x20 * (q)))
427 #define RCANFD_F_RMFDSTS(q)		(0x2008 + (0x20 * (q)))
428 #define RCANFD_F_RMDF(q, b)		(0x200c + (0x04 * (b)) + (0x20 * (q)))
429 
430 /* RSCFDnCFDRFXXx -> RCANFD_F_RFXX(x) */
431 #define RCANFD_F_RFOFFSET		(0x3000)
432 #define RCANFD_F_RFID(x)		(RCANFD_F_RFOFFSET + (0x80 * (x)))
433 #define RCANFD_F_RFPTR(x)		(RCANFD_F_RFOFFSET + 0x04 + \
434 					 (0x80 * (x)))
435 #define RCANFD_F_RFFDSTS(x)		(RCANFD_F_RFOFFSET + 0x08 + \
436 					 (0x80 * (x)))
437 #define RCANFD_F_RFDF(x, df)		(RCANFD_F_RFOFFSET + 0x0c + \
438 					 (0x80 * (x)) + (0x04 * (df)))
439 
440 /* RSCFDnCFDCFXXk -> RCANFD_F_CFXX(ch, k) */
441 #define RCANFD_F_CFOFFSET		(0x3400)
442 #define RCANFD_F_CFID(ch, idx)		(RCANFD_F_CFOFFSET + (0x180 * (ch)) + \
443 					 (0x80 * (idx)))
444 #define RCANFD_F_CFPTR(ch, idx)		(RCANFD_F_CFOFFSET + 0x04 + \
445 					 (0x180 * (ch)) + (0x80 * (idx)))
446 #define RCANFD_F_CFFDCSTS(ch, idx)	(RCANFD_F_CFOFFSET + 0x08 + \
447 					 (0x180 * (ch)) + (0x80 * (idx)))
448 #define RCANFD_F_CFDF(ch, idx, df)	(RCANFD_F_CFOFFSET + 0x0c + \
449 					 (0x180 * (ch)) + (0x80 * (idx)) + \
450 					 (0x04 * (df)))
451 
452 /* RSCFDnCFDTMXXp -> RCANFD_F_TMXX(p) */
453 #define RCANFD_F_TMID(p)		(0x4000 + (0x20 * (p)))
454 #define RCANFD_F_TMPTR(p)		(0x4004 + (0x20 * (p)))
455 #define RCANFD_F_TMFDCTR(p)		(0x4008 + (0x20 * (p)))
456 #define RCANFD_F_TMDF(p, b)		(0x400c + (0x20 * (p)) + (0x04 * (b)))
457 
458 /* RSCFDnCFDTHLACCm */
459 #define RCANFD_F_THLACC(m)		(0x6000 + (0x04 * (m)))
460 /* RSCFDnCFDRPGACCr */
461 #define RCANFD_F_RPGACC(r)		(0x6400 + (0x04 * (r)))
462 
463 /* Constants */
464 #define RCANFD_FIFO_DEPTH		8	/* Tx FIFO depth */
465 #define RCANFD_NAPI_WEIGHT		8	/* Rx poll quota */
466 
467 #define RCANFD_NUM_CHANNELS		2	/* Two channels max */
468 #define RCANFD_CHANNELS_MASK		BIT((RCANFD_NUM_CHANNELS) - 1)
469 
470 #define RCANFD_GAFL_PAGENUM(entry)	((entry) / 16)
471 #define RCANFD_CHANNEL_NUMRULES		1	/* only one rule per channel */
472 
473 /* Rx FIFO is a global resource of the controller. There are 8 such FIFOs
474  * available. Each channel gets a dedicated Rx FIFO (i.e.) the channel
475  * number is added to RFFIFO index.
476  */
477 #define RCANFD_RFFIFO_IDX		0
478 
479 /* Tx/Rx or Common FIFO is a per channel resource. Each channel has 3 Common
480  * FIFOs dedicated to them. Use the first (index 0) FIFO out of the 3 for Tx.
481  */
482 #define RCANFD_CFFIFO_IDX		0
483 
484 /* fCAN clock select register settings */
485 enum rcar_canfd_fcanclk {
486 	RCANFD_CANFDCLK = 0,		/* CANFD clock */
487 	RCANFD_EXTCLK,			/* Externally input clock */
488 };
489 
490 struct rcar_canfd_global;
491 
492 /* Channel priv data */
493 struct rcar_canfd_channel {
494 	struct can_priv can;			/* Must be the first member */
495 	struct net_device *ndev;
496 	struct rcar_canfd_global *gpriv;	/* Controller reference */
497 	void __iomem *base;			/* Register base address */
498 	struct napi_struct napi;
499 	u8  tx_len[RCANFD_FIFO_DEPTH];		/* For net stats */
500 	u32 tx_head;				/* Incremented on xmit */
501 	u32 tx_tail;				/* Incremented on xmit done */
502 	u32 channel;				/* Channel number */
503 	spinlock_t tx_lock;			/* To protect tx path */
504 };
505 
506 /* Global priv data */
507 struct rcar_canfd_global {
508 	struct rcar_canfd_channel *ch[RCANFD_NUM_CHANNELS];
509 	void __iomem *base;		/* Register base address */
510 	struct platform_device *pdev;	/* Respective platform device */
511 	struct clk *clkp;		/* Peripheral clock */
512 	struct clk *can_clk;		/* fCAN clock */
513 	enum rcar_canfd_fcanclk fcan;	/* CANFD or Ext clock */
514 	unsigned long channels_mask;	/* Enabled channels mask */
515 	bool fdmode;			/* CAN FD or Classical CAN only mode */
516 };
517 
518 /* CAN FD mode nominal rate constants */
519 static const struct can_bittiming_const rcar_canfd_nom_bittiming_const = {
520 	.name = RCANFD_DRV_NAME,
521 	.tseg1_min = 2,
522 	.tseg1_max = 128,
523 	.tseg2_min = 2,
524 	.tseg2_max = 32,
525 	.sjw_max = 32,
526 	.brp_min = 1,
527 	.brp_max = 1024,
528 	.brp_inc = 1,
529 };
530 
531 /* CAN FD mode data rate constants */
532 static const struct can_bittiming_const rcar_canfd_data_bittiming_const = {
533 	.name = RCANFD_DRV_NAME,
534 	.tseg1_min = 2,
535 	.tseg1_max = 16,
536 	.tseg2_min = 2,
537 	.tseg2_max = 8,
538 	.sjw_max = 8,
539 	.brp_min = 1,
540 	.brp_max = 256,
541 	.brp_inc = 1,
542 };
543 
544 /* Classical CAN mode bitrate constants */
545 static const struct can_bittiming_const rcar_canfd_bittiming_const = {
546 	.name = RCANFD_DRV_NAME,
547 	.tseg1_min = 4,
548 	.tseg1_max = 16,
549 	.tseg2_min = 2,
550 	.tseg2_max = 8,
551 	.sjw_max = 4,
552 	.brp_min = 1,
553 	.brp_max = 1024,
554 	.brp_inc = 1,
555 };
556 
557 /* Helper functions */
558 static inline void rcar_canfd_update(u32 mask, u32 val, u32 __iomem *reg)
559 {
560 	u32 data = readl(reg);
561 
562 	data &= ~mask;
563 	data |= (val & mask);
564 	writel(data, reg);
565 }
566 
567 static inline u32 rcar_canfd_read(void __iomem *base, u32 offset)
568 {
569 	return readl(base + (offset));
570 }
571 
572 static inline void rcar_canfd_write(void __iomem *base, u32 offset, u32 val)
573 {
574 	writel(val, base + (offset));
575 }
576 
577 static void rcar_canfd_set_bit(void __iomem *base, u32 reg, u32 val)
578 {
579 	rcar_canfd_update(val, val, base + (reg));
580 }
581 
582 static void rcar_canfd_clear_bit(void __iomem *base, u32 reg, u32 val)
583 {
584 	rcar_canfd_update(val, 0, base + (reg));
585 }
586 
587 static void rcar_canfd_update_bit(void __iomem *base, u32 reg,
588 				  u32 mask, u32 val)
589 {
590 	rcar_canfd_update(mask, val, base + (reg));
591 }
592 
593 static void rcar_canfd_get_data(struct rcar_canfd_channel *priv,
594 				struct canfd_frame *cf, u32 off)
595 {
596 	u32 i, lwords;
597 
598 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
599 	for (i = 0; i < lwords; i++)
600 		*((u32 *)cf->data + i) =
601 			rcar_canfd_read(priv->base, off + (i * sizeof(u32)));
602 }
603 
604 static void rcar_canfd_put_data(struct rcar_canfd_channel *priv,
605 				struct canfd_frame *cf, u32 off)
606 {
607 	u32 i, lwords;
608 
609 	lwords = DIV_ROUND_UP(cf->len, sizeof(u32));
610 	for (i = 0; i < lwords; i++)
611 		rcar_canfd_write(priv->base, off + (i * sizeof(u32)),
612 				 *((u32 *)cf->data + i));
613 }
614 
615 static void rcar_canfd_tx_failure_cleanup(struct net_device *ndev)
616 {
617 	u32 i;
618 
619 	for (i = 0; i < RCANFD_FIFO_DEPTH; i++)
620 		can_free_echo_skb(ndev, i);
621 }
622 
623 static int rcar_canfd_reset_controller(struct rcar_canfd_global *gpriv)
624 {
625 	u32 sts, ch;
626 	int err;
627 
628 	/* Check RAMINIT flag as CAN RAM initialization takes place
629 	 * after the MCU reset
630 	 */
631 	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
632 				 !(sts & RCANFD_GSTS_GRAMINIT), 2, 500000);
633 	if (err) {
634 		dev_dbg(&gpriv->pdev->dev, "global raminit failed\n");
635 		return err;
636 	}
637 
638 	/* Transition to Global Reset mode */
639 	rcar_canfd_clear_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GSLPR);
640 	rcar_canfd_update_bit(gpriv->base, RCANFD_GCTR,
641 			      RCANFD_GCTR_GMDC_MASK, RCANFD_GCTR_GMDC_GRESET);
642 
643 	/* Ensure Global reset mode */
644 	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
645 				 (sts & RCANFD_GSTS_GRSTSTS), 2, 500000);
646 	if (err) {
647 		dev_dbg(&gpriv->pdev->dev, "global reset failed\n");
648 		return err;
649 	}
650 
651 	/* Reset Global error flags */
652 	rcar_canfd_write(gpriv->base, RCANFD_GERFL, 0x0);
653 
654 	/* Set the controller into appropriate mode */
655 	if (gpriv->fdmode)
656 		rcar_canfd_set_bit(gpriv->base, RCANFD_GRMCFG,
657 				   RCANFD_GRMCFG_RCMC);
658 	else
659 		rcar_canfd_clear_bit(gpriv->base, RCANFD_GRMCFG,
660 				     RCANFD_GRMCFG_RCMC);
661 
662 	/* Transition all Channels to reset mode */
663 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
664 		rcar_canfd_clear_bit(gpriv->base,
665 				     RCANFD_CCTR(ch), RCANFD_CCTR_CSLPR);
666 
667 		rcar_canfd_update_bit(gpriv->base, RCANFD_CCTR(ch),
668 				      RCANFD_CCTR_CHMDC_MASK,
669 				      RCANFD_CCTR_CHDMC_CRESET);
670 
671 		/* Ensure Channel reset mode */
672 		err = readl_poll_timeout((gpriv->base + RCANFD_CSTS(ch)), sts,
673 					 (sts & RCANFD_CSTS_CRSTSTS),
674 					 2, 500000);
675 		if (err) {
676 			dev_dbg(&gpriv->pdev->dev,
677 				"channel %u reset failed\n", ch);
678 			return err;
679 		}
680 	}
681 	return 0;
682 }
683 
684 static void rcar_canfd_configure_controller(struct rcar_canfd_global *gpriv)
685 {
686 	u32 cfg, ch;
687 
688 	/* Global configuration settings */
689 
690 	/* ECC Error flag Enable */
691 	cfg = RCANFD_GCFG_EEFE;
692 
693 	if (gpriv->fdmode)
694 		/* Truncate payload to configured message size RFPLS */
695 		cfg |= RCANFD_GCFG_CMPOC;
696 
697 	/* Set External Clock if selected */
698 	if (gpriv->fcan != RCANFD_CANFDCLK)
699 		cfg |= RCANFD_GCFG_DCS;
700 
701 	rcar_canfd_set_bit(gpriv->base, RCANFD_GCFG, cfg);
702 
703 	/* Channel configuration settings */
704 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
705 		rcar_canfd_set_bit(gpriv->base, RCANFD_CCTR(ch),
706 				   RCANFD_CCTR_ERRD);
707 		rcar_canfd_update_bit(gpriv->base, RCANFD_CCTR(ch),
708 				      RCANFD_CCTR_BOM_MASK,
709 				      RCANFD_CCTR_BOM_BENTRY);
710 	}
711 }
712 
713 static void rcar_canfd_configure_afl_rules(struct rcar_canfd_global *gpriv,
714 					   u32 ch)
715 {
716 	u32 cfg;
717 	int offset, start, page, num_rules = RCANFD_CHANNEL_NUMRULES;
718 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
719 
720 	if (ch == 0) {
721 		start = 0; /* Channel 0 always starts from 0th rule */
722 	} else {
723 		/* Get number of Channel 0 rules and adjust */
724 		cfg = rcar_canfd_read(gpriv->base, RCANFD_GAFLCFG0);
725 		start = RCANFD_GAFLCFG_GETRNC(0, cfg);
726 	}
727 
728 	/* Enable write access to entry */
729 	page = RCANFD_GAFL_PAGENUM(start);
730 	rcar_canfd_set_bit(gpriv->base, RCANFD_GAFLECTR,
731 			   (RCANFD_GAFLECTR_AFLPN(page) |
732 			    RCANFD_GAFLECTR_AFLDAE));
733 
734 	/* Write number of rules for channel */
735 	rcar_canfd_set_bit(gpriv->base, RCANFD_GAFLCFG0,
736 			   RCANFD_GAFLCFG_SETRNC(ch, num_rules));
737 	if (gpriv->fdmode)
738 		offset = RCANFD_F_GAFL_OFFSET;
739 	else
740 		offset = RCANFD_C_GAFL_OFFSET;
741 
742 	/* Accept all IDs */
743 	rcar_canfd_write(gpriv->base, RCANFD_GAFLID(offset, start), 0);
744 	/* IDE or RTR is not considered for matching */
745 	rcar_canfd_write(gpriv->base, RCANFD_GAFLM(offset, start), 0);
746 	/* Any data length accepted */
747 	rcar_canfd_write(gpriv->base, RCANFD_GAFLP0(offset, start), 0);
748 	/* Place the msg in corresponding Rx FIFO entry */
749 	rcar_canfd_write(gpriv->base, RCANFD_GAFLP1(offset, start),
750 			 RCANFD_GAFLP1_GAFLFDP(ridx));
751 
752 	/* Disable write access to page */
753 	rcar_canfd_clear_bit(gpriv->base,
754 			     RCANFD_GAFLECTR, RCANFD_GAFLECTR_AFLDAE);
755 }
756 
757 static void rcar_canfd_configure_rx(struct rcar_canfd_global *gpriv, u32 ch)
758 {
759 	/* Rx FIFO is used for reception */
760 	u32 cfg;
761 	u16 rfdc, rfpls;
762 
763 	/* Select Rx FIFO based on channel */
764 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
765 
766 	rfdc = 2;		/* b010 - 8 messages Rx FIFO depth */
767 	if (gpriv->fdmode)
768 		rfpls = 7;	/* b111 - Max 64 bytes payload */
769 	else
770 		rfpls = 0;	/* b000 - Max 8 bytes payload */
771 
772 	cfg = (RCANFD_RFCC_RFIM | RCANFD_RFCC_RFDC(rfdc) |
773 		RCANFD_RFCC_RFPLS(rfpls) | RCANFD_RFCC_RFIE);
774 	rcar_canfd_write(gpriv->base, RCANFD_RFCC(ridx), cfg);
775 }
776 
777 static void rcar_canfd_configure_tx(struct rcar_canfd_global *gpriv, u32 ch)
778 {
779 	/* Tx/Rx(Common) FIFO configured in Tx mode is
780 	 * used for transmission
781 	 *
782 	 * Each channel has 3 Common FIFO dedicated to them.
783 	 * Use the 1st (index 0) out of 3
784 	 */
785 	u32 cfg;
786 	u16 cftml, cfm, cfdc, cfpls;
787 
788 	cftml = 0;		/* 0th buffer */
789 	cfm = 1;		/* b01 - Transmit mode */
790 	cfdc = 2;		/* b010 - 8 messages Tx FIFO depth */
791 	if (gpriv->fdmode)
792 		cfpls = 7;	/* b111 - Max 64 bytes payload */
793 	else
794 		cfpls = 0;	/* b000 - Max 8 bytes payload */
795 
796 	cfg = (RCANFD_CFCC_CFTML(cftml) | RCANFD_CFCC_CFM(cfm) |
797 		RCANFD_CFCC_CFIM | RCANFD_CFCC_CFDC(cfdc) |
798 		RCANFD_CFCC_CFPLS(cfpls) | RCANFD_CFCC_CFTXIE);
799 	rcar_canfd_write(gpriv->base, RCANFD_CFCC(ch, RCANFD_CFFIFO_IDX), cfg);
800 
801 	if (gpriv->fdmode)
802 		/* Clear FD mode specific control/status register */
803 		rcar_canfd_write(gpriv->base,
804 				 RCANFD_F_CFFDCSTS(ch, RCANFD_CFFIFO_IDX), 0);
805 }
806 
807 static void rcar_canfd_enable_global_interrupts(struct rcar_canfd_global *gpriv)
808 {
809 	u32 ctr;
810 
811 	/* Clear any stray error interrupt flags */
812 	rcar_canfd_write(gpriv->base, RCANFD_GERFL, 0);
813 
814 	/* Global interrupts setup */
815 	ctr = RCANFD_GCTR_MEIE;
816 	if (gpriv->fdmode)
817 		ctr |= RCANFD_GCTR_CFMPOFIE;
818 
819 	rcar_canfd_set_bit(gpriv->base, RCANFD_GCTR, ctr);
820 }
821 
822 static void rcar_canfd_disable_global_interrupts(struct rcar_canfd_global
823 						 *gpriv)
824 {
825 	/* Disable all interrupts */
826 	rcar_canfd_write(gpriv->base, RCANFD_GCTR, 0);
827 
828 	/* Clear any stray error interrupt flags */
829 	rcar_canfd_write(gpriv->base, RCANFD_GERFL, 0);
830 }
831 
832 static void rcar_canfd_enable_channel_interrupts(struct rcar_canfd_channel
833 						 *priv)
834 {
835 	u32 ctr, ch = priv->channel;
836 
837 	/* Clear any stray error flags */
838 	rcar_canfd_write(priv->base, RCANFD_CERFL(ch), 0);
839 
840 	/* Channel interrupts setup */
841 	ctr = (RCANFD_CCTR_TAIE |
842 	       RCANFD_CCTR_ALIE | RCANFD_CCTR_BLIE |
843 	       RCANFD_CCTR_OLIE | RCANFD_CCTR_BORIE |
844 	       RCANFD_CCTR_BOEIE | RCANFD_CCTR_EPIE |
845 	       RCANFD_CCTR_EWIE | RCANFD_CCTR_BEIE);
846 	rcar_canfd_set_bit(priv->base, RCANFD_CCTR(ch), ctr);
847 }
848 
849 static void rcar_canfd_disable_channel_interrupts(struct rcar_canfd_channel
850 						  *priv)
851 {
852 	u32 ctr, ch = priv->channel;
853 
854 	ctr = (RCANFD_CCTR_TAIE |
855 	       RCANFD_CCTR_ALIE | RCANFD_CCTR_BLIE |
856 	       RCANFD_CCTR_OLIE | RCANFD_CCTR_BORIE |
857 	       RCANFD_CCTR_BOEIE | RCANFD_CCTR_EPIE |
858 	       RCANFD_CCTR_EWIE | RCANFD_CCTR_BEIE);
859 	rcar_canfd_clear_bit(priv->base, RCANFD_CCTR(ch), ctr);
860 
861 	/* Clear any stray error flags */
862 	rcar_canfd_write(priv->base, RCANFD_CERFL(ch), 0);
863 }
864 
865 static void rcar_canfd_global_error(struct net_device *ndev)
866 {
867 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
868 	struct rcar_canfd_global *gpriv = priv->gpriv;
869 	struct net_device_stats *stats = &ndev->stats;
870 	u32 ch = priv->channel;
871 	u32 gerfl, sts;
872 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
873 
874 	gerfl = rcar_canfd_read(priv->base, RCANFD_GERFL);
875 	if ((gerfl & RCANFD_GERFL_EEF0) && (ch == 0)) {
876 		netdev_dbg(ndev, "Ch0: ECC Error flag\n");
877 		stats->tx_dropped++;
878 	}
879 	if ((gerfl & RCANFD_GERFL_EEF1) && (ch == 1)) {
880 		netdev_dbg(ndev, "Ch1: ECC Error flag\n");
881 		stats->tx_dropped++;
882 	}
883 	if (gerfl & RCANFD_GERFL_MES) {
884 		sts = rcar_canfd_read(priv->base,
885 				      RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX));
886 		if (sts & RCANFD_CFSTS_CFMLT) {
887 			netdev_dbg(ndev, "Tx Message Lost flag\n");
888 			stats->tx_dropped++;
889 			rcar_canfd_write(priv->base,
890 					 RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX),
891 					 sts & ~RCANFD_CFSTS_CFMLT);
892 		}
893 
894 		sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(ridx));
895 		if (sts & RCANFD_RFSTS_RFMLT) {
896 			netdev_dbg(ndev, "Rx Message Lost flag\n");
897 			stats->rx_dropped++;
898 			rcar_canfd_write(priv->base, RCANFD_RFSTS(ridx),
899 					 sts & ~RCANFD_RFSTS_RFMLT);
900 		}
901 	}
902 	if (gpriv->fdmode && gerfl & RCANFD_GERFL_CMPOF) {
903 		/* Message Lost flag will be set for respective channel
904 		 * when this condition happens with counters and flags
905 		 * already updated.
906 		 */
907 		netdev_dbg(ndev, "global payload overflow interrupt\n");
908 	}
909 
910 	/* Clear all global error interrupts. Only affected channels bits
911 	 * get cleared
912 	 */
913 	rcar_canfd_write(priv->base, RCANFD_GERFL, 0);
914 }
915 
916 static void rcar_canfd_error(struct net_device *ndev, u32 cerfl,
917 			     u16 txerr, u16 rxerr)
918 {
919 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
920 	struct net_device_stats *stats = &ndev->stats;
921 	struct can_frame *cf;
922 	struct sk_buff *skb;
923 	u32 ch = priv->channel;
924 
925 	netdev_dbg(ndev, "ch erfl %x txerr %u rxerr %u\n", cerfl, txerr, rxerr);
926 
927 	/* Propagate the error condition to the CAN stack */
928 	skb = alloc_can_err_skb(ndev, &cf);
929 	if (!skb) {
930 		stats->rx_dropped++;
931 		return;
932 	}
933 
934 	/* Channel error interrupts */
935 	if (cerfl & RCANFD_CERFL_BEF) {
936 		netdev_dbg(ndev, "Bus error\n");
937 		cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
938 		cf->data[2] = CAN_ERR_PROT_UNSPEC;
939 		priv->can.can_stats.bus_error++;
940 	}
941 	if (cerfl & RCANFD_CERFL_ADERR) {
942 		netdev_dbg(ndev, "ACK Delimiter Error\n");
943 		stats->tx_errors++;
944 		cf->data[3] |= CAN_ERR_PROT_LOC_ACK_DEL;
945 	}
946 	if (cerfl & RCANFD_CERFL_B0ERR) {
947 		netdev_dbg(ndev, "Bit Error (dominant)\n");
948 		stats->tx_errors++;
949 		cf->data[2] |= CAN_ERR_PROT_BIT0;
950 	}
951 	if (cerfl & RCANFD_CERFL_B1ERR) {
952 		netdev_dbg(ndev, "Bit Error (recessive)\n");
953 		stats->tx_errors++;
954 		cf->data[2] |= CAN_ERR_PROT_BIT1;
955 	}
956 	if (cerfl & RCANFD_CERFL_CERR) {
957 		netdev_dbg(ndev, "CRC Error\n");
958 		stats->rx_errors++;
959 		cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
960 	}
961 	if (cerfl & RCANFD_CERFL_AERR) {
962 		netdev_dbg(ndev, "ACK Error\n");
963 		stats->tx_errors++;
964 		cf->can_id |= CAN_ERR_ACK;
965 		cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
966 	}
967 	if (cerfl & RCANFD_CERFL_FERR) {
968 		netdev_dbg(ndev, "Form Error\n");
969 		stats->rx_errors++;
970 		cf->data[2] |= CAN_ERR_PROT_FORM;
971 	}
972 	if (cerfl & RCANFD_CERFL_SERR) {
973 		netdev_dbg(ndev, "Stuff Error\n");
974 		stats->rx_errors++;
975 		cf->data[2] |= CAN_ERR_PROT_STUFF;
976 	}
977 	if (cerfl & RCANFD_CERFL_ALF) {
978 		netdev_dbg(ndev, "Arbitration lost Error\n");
979 		priv->can.can_stats.arbitration_lost++;
980 		cf->can_id |= CAN_ERR_LOSTARB;
981 		cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
982 	}
983 	if (cerfl & RCANFD_CERFL_BLF) {
984 		netdev_dbg(ndev, "Bus Lock Error\n");
985 		stats->rx_errors++;
986 		cf->can_id |= CAN_ERR_BUSERROR;
987 	}
988 	if (cerfl & RCANFD_CERFL_EWF) {
989 		netdev_dbg(ndev, "Error warning interrupt\n");
990 		priv->can.state = CAN_STATE_ERROR_WARNING;
991 		priv->can.can_stats.error_warning++;
992 		cf->can_id |= CAN_ERR_CRTL;
993 		cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
994 			CAN_ERR_CRTL_RX_WARNING;
995 		cf->data[6] = txerr;
996 		cf->data[7] = rxerr;
997 	}
998 	if (cerfl & RCANFD_CERFL_EPF) {
999 		netdev_dbg(ndev, "Error passive interrupt\n");
1000 		priv->can.state = CAN_STATE_ERROR_PASSIVE;
1001 		priv->can.can_stats.error_passive++;
1002 		cf->can_id |= CAN_ERR_CRTL;
1003 		cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
1004 			CAN_ERR_CRTL_RX_PASSIVE;
1005 		cf->data[6] = txerr;
1006 		cf->data[7] = rxerr;
1007 	}
1008 	if (cerfl & RCANFD_CERFL_BOEF) {
1009 		netdev_dbg(ndev, "Bus-off entry interrupt\n");
1010 		rcar_canfd_tx_failure_cleanup(ndev);
1011 		priv->can.state = CAN_STATE_BUS_OFF;
1012 		priv->can.can_stats.bus_off++;
1013 		can_bus_off(ndev);
1014 		cf->can_id |= CAN_ERR_BUSOFF;
1015 	}
1016 	if (cerfl & RCANFD_CERFL_OVLF) {
1017 		netdev_dbg(ndev,
1018 			   "Overload Frame Transmission error interrupt\n");
1019 		stats->tx_errors++;
1020 		cf->can_id |= CAN_ERR_PROT;
1021 		cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
1022 	}
1023 
1024 	/* Clear channel error interrupts that are handled */
1025 	rcar_canfd_write(priv->base, RCANFD_CERFL(ch),
1026 			 RCANFD_CERFL_ERR(~cerfl));
1027 	stats->rx_packets++;
1028 	stats->rx_bytes += cf->len;
1029 	netif_rx(skb);
1030 }
1031 
1032 static void rcar_canfd_tx_done(struct net_device *ndev)
1033 {
1034 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1035 	struct net_device_stats *stats = &ndev->stats;
1036 	u32 sts;
1037 	unsigned long flags;
1038 	u32 ch = priv->channel;
1039 
1040 	do {
1041 		u8 unsent, sent;
1042 
1043 		sent = priv->tx_tail % RCANFD_FIFO_DEPTH;
1044 		stats->tx_packets++;
1045 		stats->tx_bytes += priv->tx_len[sent];
1046 		priv->tx_len[sent] = 0;
1047 		can_get_echo_skb(ndev, sent, NULL);
1048 
1049 		spin_lock_irqsave(&priv->tx_lock, flags);
1050 		priv->tx_tail++;
1051 		sts = rcar_canfd_read(priv->base,
1052 				      RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX));
1053 		unsent = RCANFD_CFSTS_CFMC(sts);
1054 
1055 		/* Wake producer only when there is room */
1056 		if (unsent != RCANFD_FIFO_DEPTH)
1057 			netif_wake_queue(ndev);
1058 
1059 		if (priv->tx_head - priv->tx_tail <= unsent) {
1060 			spin_unlock_irqrestore(&priv->tx_lock, flags);
1061 			break;
1062 		}
1063 		spin_unlock_irqrestore(&priv->tx_lock, flags);
1064 
1065 	} while (1);
1066 
1067 	/* Clear interrupt */
1068 	rcar_canfd_write(priv->base, RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX),
1069 			 sts & ~RCANFD_CFSTS_CFTXIF);
1070 	can_led_event(ndev, CAN_LED_EVENT_TX);
1071 }
1072 
1073 static irqreturn_t rcar_canfd_global_interrupt(int irq, void *dev_id)
1074 {
1075 	struct rcar_canfd_global *gpriv = dev_id;
1076 	struct net_device *ndev;
1077 	struct rcar_canfd_channel *priv;
1078 	u32 sts, gerfl;
1079 	u32 ch, ridx;
1080 
1081 	/* Global error interrupts still indicate a condition specific
1082 	 * to a channel. RxFIFO interrupt is a global interrupt.
1083 	 */
1084 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
1085 		priv = gpriv->ch[ch];
1086 		ndev = priv->ndev;
1087 		ridx = ch + RCANFD_RFFIFO_IDX;
1088 
1089 		/* Global error interrupts */
1090 		gerfl = rcar_canfd_read(priv->base, RCANFD_GERFL);
1091 		if (unlikely(RCANFD_GERFL_ERR(gpriv, gerfl)))
1092 			rcar_canfd_global_error(ndev);
1093 
1094 		/* Handle Rx interrupts */
1095 		sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(ridx));
1096 		if (likely(sts & RCANFD_RFSTS_RFIF)) {
1097 			if (napi_schedule_prep(&priv->napi)) {
1098 				/* Disable Rx FIFO interrupts */
1099 				rcar_canfd_clear_bit(priv->base,
1100 						     RCANFD_RFCC(ridx),
1101 						     RCANFD_RFCC_RFIE);
1102 				__napi_schedule(&priv->napi);
1103 			}
1104 		}
1105 	}
1106 	return IRQ_HANDLED;
1107 }
1108 
1109 static void rcar_canfd_state_change(struct net_device *ndev,
1110 				    u16 txerr, u16 rxerr)
1111 {
1112 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1113 	struct net_device_stats *stats = &ndev->stats;
1114 	enum can_state rx_state, tx_state, state = priv->can.state;
1115 	struct can_frame *cf;
1116 	struct sk_buff *skb;
1117 
1118 	/* Handle transition from error to normal states */
1119 	if (txerr < 96 && rxerr < 96)
1120 		state = CAN_STATE_ERROR_ACTIVE;
1121 	else if (txerr < 128 && rxerr < 128)
1122 		state = CAN_STATE_ERROR_WARNING;
1123 
1124 	if (state != priv->can.state) {
1125 		netdev_dbg(ndev, "state: new %d, old %d: txerr %u, rxerr %u\n",
1126 			   state, priv->can.state, txerr, rxerr);
1127 		skb = alloc_can_err_skb(ndev, &cf);
1128 		if (!skb) {
1129 			stats->rx_dropped++;
1130 			return;
1131 		}
1132 		tx_state = txerr >= rxerr ? state : 0;
1133 		rx_state = txerr <= rxerr ? state : 0;
1134 
1135 		can_change_state(ndev, cf, tx_state, rx_state);
1136 		stats->rx_packets++;
1137 		stats->rx_bytes += cf->len;
1138 		netif_rx(skb);
1139 	}
1140 }
1141 
1142 static irqreturn_t rcar_canfd_channel_interrupt(int irq, void *dev_id)
1143 {
1144 	struct rcar_canfd_global *gpriv = dev_id;
1145 	struct net_device *ndev;
1146 	struct rcar_canfd_channel *priv;
1147 	u32 sts, ch, cerfl;
1148 	u16 txerr, rxerr;
1149 
1150 	/* Common FIFO is a per channel resource */
1151 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
1152 		priv = gpriv->ch[ch];
1153 		ndev = priv->ndev;
1154 
1155 		/* Channel error interrupts */
1156 		cerfl = rcar_canfd_read(priv->base, RCANFD_CERFL(ch));
1157 		sts = rcar_canfd_read(priv->base, RCANFD_CSTS(ch));
1158 		txerr = RCANFD_CSTS_TECCNT(sts);
1159 		rxerr = RCANFD_CSTS_RECCNT(sts);
1160 		if (unlikely(RCANFD_CERFL_ERR(cerfl)))
1161 			rcar_canfd_error(ndev, cerfl, txerr, rxerr);
1162 
1163 		/* Handle state change to lower states */
1164 		if (unlikely((priv->can.state != CAN_STATE_ERROR_ACTIVE) &&
1165 			     (priv->can.state != CAN_STATE_BUS_OFF)))
1166 			rcar_canfd_state_change(ndev, txerr, rxerr);
1167 
1168 		/* Handle Tx interrupts */
1169 		sts = rcar_canfd_read(priv->base,
1170 				      RCANFD_CFSTS(ch, RCANFD_CFFIFO_IDX));
1171 		if (likely(sts & RCANFD_CFSTS_CFTXIF))
1172 			rcar_canfd_tx_done(ndev);
1173 	}
1174 	return IRQ_HANDLED;
1175 }
1176 
1177 static void rcar_canfd_set_bittiming(struct net_device *dev)
1178 {
1179 	struct rcar_canfd_channel *priv = netdev_priv(dev);
1180 	const struct can_bittiming *bt = &priv->can.bittiming;
1181 	const struct can_bittiming *dbt = &priv->can.data_bittiming;
1182 	u16 brp, sjw, tseg1, tseg2;
1183 	u32 cfg;
1184 	u32 ch = priv->channel;
1185 
1186 	/* Nominal bit timing settings */
1187 	brp = bt->brp - 1;
1188 	sjw = bt->sjw - 1;
1189 	tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
1190 	tseg2 = bt->phase_seg2 - 1;
1191 
1192 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1193 		/* CAN FD only mode */
1194 		cfg = (RCANFD_NCFG_NTSEG1(tseg1) | RCANFD_NCFG_NBRP(brp) |
1195 		       RCANFD_NCFG_NSJW(sjw) | RCANFD_NCFG_NTSEG2(tseg2));
1196 
1197 		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
1198 		netdev_dbg(priv->ndev, "nrate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
1199 			   brp, sjw, tseg1, tseg2);
1200 
1201 		/* Data bit timing settings */
1202 		brp = dbt->brp - 1;
1203 		sjw = dbt->sjw - 1;
1204 		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
1205 		tseg2 = dbt->phase_seg2 - 1;
1206 
1207 		cfg = (RCANFD_DCFG_DTSEG1(tseg1) | RCANFD_DCFG_DBRP(brp) |
1208 		       RCANFD_DCFG_DSJW(sjw) | RCANFD_DCFG_DTSEG2(tseg2));
1209 
1210 		rcar_canfd_write(priv->base, RCANFD_F_DCFG(ch), cfg);
1211 		netdev_dbg(priv->ndev, "drate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
1212 			   brp, sjw, tseg1, tseg2);
1213 	} else {
1214 		/* Classical CAN only mode */
1215 		cfg = (RCANFD_CFG_TSEG1(tseg1) | RCANFD_CFG_BRP(brp) |
1216 			RCANFD_CFG_SJW(sjw) | RCANFD_CFG_TSEG2(tseg2));
1217 
1218 		rcar_canfd_write(priv->base, RCANFD_CCFG(ch), cfg);
1219 		netdev_dbg(priv->ndev,
1220 			   "rate: brp %u, sjw %u, tseg1 %u, tseg2 %u\n",
1221 			   brp, sjw, tseg1, tseg2);
1222 	}
1223 }
1224 
1225 static int rcar_canfd_start(struct net_device *ndev)
1226 {
1227 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1228 	int err = -EOPNOTSUPP;
1229 	u32 sts, ch = priv->channel;
1230 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
1231 
1232 	rcar_canfd_set_bittiming(ndev);
1233 
1234 	rcar_canfd_enable_channel_interrupts(priv);
1235 
1236 	/* Set channel to Operational mode */
1237 	rcar_canfd_update_bit(priv->base, RCANFD_CCTR(ch),
1238 			      RCANFD_CCTR_CHMDC_MASK, RCANFD_CCTR_CHDMC_COPM);
1239 
1240 	/* Verify channel mode change */
1241 	err = readl_poll_timeout((priv->base + RCANFD_CSTS(ch)), sts,
1242 				 (sts & RCANFD_CSTS_COMSTS), 2, 500000);
1243 	if (err) {
1244 		netdev_err(ndev, "channel %u communication state failed\n", ch);
1245 		goto fail_mode_change;
1246 	}
1247 
1248 	/* Enable Common & Rx FIFO */
1249 	rcar_canfd_set_bit(priv->base, RCANFD_CFCC(ch, RCANFD_CFFIFO_IDX),
1250 			   RCANFD_CFCC_CFE);
1251 	rcar_canfd_set_bit(priv->base, RCANFD_RFCC(ridx), RCANFD_RFCC_RFE);
1252 
1253 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1254 	return 0;
1255 
1256 fail_mode_change:
1257 	rcar_canfd_disable_channel_interrupts(priv);
1258 	return err;
1259 }
1260 
1261 static int rcar_canfd_open(struct net_device *ndev)
1262 {
1263 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1264 	struct rcar_canfd_global *gpriv = priv->gpriv;
1265 	int err;
1266 
1267 	/* Peripheral clock is already enabled in probe */
1268 	err = clk_prepare_enable(gpriv->can_clk);
1269 	if (err) {
1270 		netdev_err(ndev, "failed to enable CAN clock, error %d\n", err);
1271 		goto out_clock;
1272 	}
1273 
1274 	err = open_candev(ndev);
1275 	if (err) {
1276 		netdev_err(ndev, "open_candev() failed, error %d\n", err);
1277 		goto out_can_clock;
1278 	}
1279 
1280 	napi_enable(&priv->napi);
1281 	err = rcar_canfd_start(ndev);
1282 	if (err)
1283 		goto out_close;
1284 	netif_start_queue(ndev);
1285 	can_led_event(ndev, CAN_LED_EVENT_OPEN);
1286 	return 0;
1287 out_close:
1288 	napi_disable(&priv->napi);
1289 	close_candev(ndev);
1290 out_can_clock:
1291 	clk_disable_unprepare(gpriv->can_clk);
1292 out_clock:
1293 	return err;
1294 }
1295 
1296 static void rcar_canfd_stop(struct net_device *ndev)
1297 {
1298 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1299 	int err;
1300 	u32 sts, ch = priv->channel;
1301 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
1302 
1303 	/* Transition to channel reset mode  */
1304 	rcar_canfd_update_bit(priv->base, RCANFD_CCTR(ch),
1305 			      RCANFD_CCTR_CHMDC_MASK, RCANFD_CCTR_CHDMC_CRESET);
1306 
1307 	/* Check Channel reset mode */
1308 	err = readl_poll_timeout((priv->base + RCANFD_CSTS(ch)), sts,
1309 				 (sts & RCANFD_CSTS_CRSTSTS), 2, 500000);
1310 	if (err)
1311 		netdev_err(ndev, "channel %u reset failed\n", ch);
1312 
1313 	rcar_canfd_disable_channel_interrupts(priv);
1314 
1315 	/* Disable Common & Rx FIFO */
1316 	rcar_canfd_clear_bit(priv->base, RCANFD_CFCC(ch, RCANFD_CFFIFO_IDX),
1317 			     RCANFD_CFCC_CFE);
1318 	rcar_canfd_clear_bit(priv->base, RCANFD_RFCC(ridx), RCANFD_RFCC_RFE);
1319 
1320 	/* Set the state as STOPPED */
1321 	priv->can.state = CAN_STATE_STOPPED;
1322 }
1323 
1324 static int rcar_canfd_close(struct net_device *ndev)
1325 {
1326 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1327 	struct rcar_canfd_global *gpriv = priv->gpriv;
1328 
1329 	netif_stop_queue(ndev);
1330 	rcar_canfd_stop(ndev);
1331 	napi_disable(&priv->napi);
1332 	clk_disable_unprepare(gpriv->can_clk);
1333 	close_candev(ndev);
1334 	can_led_event(ndev, CAN_LED_EVENT_STOP);
1335 	return 0;
1336 }
1337 
1338 static netdev_tx_t rcar_canfd_start_xmit(struct sk_buff *skb,
1339 					 struct net_device *ndev)
1340 {
1341 	struct rcar_canfd_channel *priv = netdev_priv(ndev);
1342 	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
1343 	u32 sts = 0, id, dlc;
1344 	unsigned long flags;
1345 	u32 ch = priv->channel;
1346 
1347 	if (can_dropped_invalid_skb(ndev, skb))
1348 		return NETDEV_TX_OK;
1349 
1350 	if (cf->can_id & CAN_EFF_FLAG) {
1351 		id = cf->can_id & CAN_EFF_MASK;
1352 		id |= RCANFD_CFID_CFIDE;
1353 	} else {
1354 		id = cf->can_id & CAN_SFF_MASK;
1355 	}
1356 
1357 	if (cf->can_id & CAN_RTR_FLAG)
1358 		id |= RCANFD_CFID_CFRTR;
1359 
1360 	dlc = RCANFD_CFPTR_CFDLC(can_fd_len2dlc(cf->len));
1361 
1362 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1363 		rcar_canfd_write(priv->base,
1364 				 RCANFD_F_CFID(ch, RCANFD_CFFIFO_IDX), id);
1365 		rcar_canfd_write(priv->base,
1366 				 RCANFD_F_CFPTR(ch, RCANFD_CFFIFO_IDX), dlc);
1367 
1368 		if (can_is_canfd_skb(skb)) {
1369 			/* CAN FD frame format */
1370 			sts |= RCANFD_CFFDCSTS_CFFDF;
1371 			if (cf->flags & CANFD_BRS)
1372 				sts |= RCANFD_CFFDCSTS_CFBRS;
1373 
1374 			if (priv->can.state == CAN_STATE_ERROR_PASSIVE)
1375 				sts |= RCANFD_CFFDCSTS_CFESI;
1376 		}
1377 
1378 		rcar_canfd_write(priv->base,
1379 				 RCANFD_F_CFFDCSTS(ch, RCANFD_CFFIFO_IDX), sts);
1380 
1381 		rcar_canfd_put_data(priv, cf,
1382 				    RCANFD_F_CFDF(ch, RCANFD_CFFIFO_IDX, 0));
1383 	} else {
1384 		rcar_canfd_write(priv->base,
1385 				 RCANFD_C_CFID(ch, RCANFD_CFFIFO_IDX), id);
1386 		rcar_canfd_write(priv->base,
1387 				 RCANFD_C_CFPTR(ch, RCANFD_CFFIFO_IDX), dlc);
1388 		rcar_canfd_put_data(priv, cf,
1389 				    RCANFD_C_CFDF(ch, RCANFD_CFFIFO_IDX, 0));
1390 	}
1391 
1392 	priv->tx_len[priv->tx_head % RCANFD_FIFO_DEPTH] = cf->len;
1393 	can_put_echo_skb(skb, ndev, priv->tx_head % RCANFD_FIFO_DEPTH, 0);
1394 
1395 	spin_lock_irqsave(&priv->tx_lock, flags);
1396 	priv->tx_head++;
1397 
1398 	/* Stop the queue if we've filled all FIFO entries */
1399 	if (priv->tx_head - priv->tx_tail >= RCANFD_FIFO_DEPTH)
1400 		netif_stop_queue(ndev);
1401 
1402 	/* Start Tx: Write 0xff to CFPC to increment the CPU-side
1403 	 * pointer for the Common FIFO
1404 	 */
1405 	rcar_canfd_write(priv->base,
1406 			 RCANFD_CFPCTR(ch, RCANFD_CFFIFO_IDX), 0xff);
1407 
1408 	spin_unlock_irqrestore(&priv->tx_lock, flags);
1409 	return NETDEV_TX_OK;
1410 }
1411 
1412 static void rcar_canfd_rx_pkt(struct rcar_canfd_channel *priv)
1413 {
1414 	struct net_device_stats *stats = &priv->ndev->stats;
1415 	struct canfd_frame *cf;
1416 	struct sk_buff *skb;
1417 	u32 sts = 0, id, dlc;
1418 	u32 ch = priv->channel;
1419 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
1420 
1421 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1422 		id = rcar_canfd_read(priv->base, RCANFD_F_RFID(ridx));
1423 		dlc = rcar_canfd_read(priv->base, RCANFD_F_RFPTR(ridx));
1424 
1425 		sts = rcar_canfd_read(priv->base, RCANFD_F_RFFDSTS(ridx));
1426 		if (sts & RCANFD_RFFDSTS_RFFDF)
1427 			skb = alloc_canfd_skb(priv->ndev, &cf);
1428 		else
1429 			skb = alloc_can_skb(priv->ndev,
1430 					    (struct can_frame **)&cf);
1431 	} else {
1432 		id = rcar_canfd_read(priv->base, RCANFD_C_RFID(ridx));
1433 		dlc = rcar_canfd_read(priv->base, RCANFD_C_RFPTR(ridx));
1434 		skb = alloc_can_skb(priv->ndev, (struct can_frame **)&cf);
1435 	}
1436 
1437 	if (!skb) {
1438 		stats->rx_dropped++;
1439 		return;
1440 	}
1441 
1442 	if (id & RCANFD_RFID_RFIDE)
1443 		cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
1444 	else
1445 		cf->can_id = id & CAN_SFF_MASK;
1446 
1447 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1448 		if (sts & RCANFD_RFFDSTS_RFFDF)
1449 			cf->len = can_fd_dlc2len(RCANFD_RFPTR_RFDLC(dlc));
1450 		else
1451 			cf->len = can_cc_dlc2len(RCANFD_RFPTR_RFDLC(dlc));
1452 
1453 		if (sts & RCANFD_RFFDSTS_RFESI) {
1454 			cf->flags |= CANFD_ESI;
1455 			netdev_dbg(priv->ndev, "ESI Error\n");
1456 		}
1457 
1458 		if (!(sts & RCANFD_RFFDSTS_RFFDF) && (id & RCANFD_RFID_RFRTR)) {
1459 			cf->can_id |= CAN_RTR_FLAG;
1460 		} else {
1461 			if (sts & RCANFD_RFFDSTS_RFBRS)
1462 				cf->flags |= CANFD_BRS;
1463 
1464 			rcar_canfd_get_data(priv, cf, RCANFD_F_RFDF(ridx, 0));
1465 		}
1466 	} else {
1467 		cf->len = can_cc_dlc2len(RCANFD_RFPTR_RFDLC(dlc));
1468 		if (id & RCANFD_RFID_RFRTR)
1469 			cf->can_id |= CAN_RTR_FLAG;
1470 		else
1471 			rcar_canfd_get_data(priv, cf, RCANFD_C_RFDF(ridx, 0));
1472 	}
1473 
1474 	/* Write 0xff to RFPC to increment the CPU-side
1475 	 * pointer of the Rx FIFO
1476 	 */
1477 	rcar_canfd_write(priv->base, RCANFD_RFPCTR(ridx), 0xff);
1478 
1479 	can_led_event(priv->ndev, CAN_LED_EVENT_RX);
1480 
1481 	stats->rx_bytes += cf->len;
1482 	stats->rx_packets++;
1483 	netif_receive_skb(skb);
1484 }
1485 
1486 static int rcar_canfd_rx_poll(struct napi_struct *napi, int quota)
1487 {
1488 	struct rcar_canfd_channel *priv =
1489 		container_of(napi, struct rcar_canfd_channel, napi);
1490 	int num_pkts;
1491 	u32 sts;
1492 	u32 ch = priv->channel;
1493 	u32 ridx = ch + RCANFD_RFFIFO_IDX;
1494 
1495 	for (num_pkts = 0; num_pkts < quota; num_pkts++) {
1496 		sts = rcar_canfd_read(priv->base, RCANFD_RFSTS(ridx));
1497 		/* Check FIFO empty condition */
1498 		if (sts & RCANFD_RFSTS_RFEMP)
1499 			break;
1500 
1501 		rcar_canfd_rx_pkt(priv);
1502 
1503 		/* Clear interrupt bit */
1504 		if (sts & RCANFD_RFSTS_RFIF)
1505 			rcar_canfd_write(priv->base, RCANFD_RFSTS(ridx),
1506 					 sts & ~RCANFD_RFSTS_RFIF);
1507 	}
1508 
1509 	/* All packets processed */
1510 	if (num_pkts < quota) {
1511 		if (napi_complete_done(napi, num_pkts)) {
1512 			/* Enable Rx FIFO interrupts */
1513 			rcar_canfd_set_bit(priv->base, RCANFD_RFCC(ridx),
1514 					   RCANFD_RFCC_RFIE);
1515 		}
1516 	}
1517 	return num_pkts;
1518 }
1519 
1520 static int rcar_canfd_do_set_mode(struct net_device *ndev, enum can_mode mode)
1521 {
1522 	int err;
1523 
1524 	switch (mode) {
1525 	case CAN_MODE_START:
1526 		err = rcar_canfd_start(ndev);
1527 		if (err)
1528 			return err;
1529 		netif_wake_queue(ndev);
1530 		return 0;
1531 	default:
1532 		return -EOPNOTSUPP;
1533 	}
1534 }
1535 
1536 static int rcar_canfd_get_berr_counter(const struct net_device *dev,
1537 				       struct can_berr_counter *bec)
1538 {
1539 	struct rcar_canfd_channel *priv = netdev_priv(dev);
1540 	u32 val, ch = priv->channel;
1541 
1542 	/* Peripheral clock is already enabled in probe */
1543 	val = rcar_canfd_read(priv->base, RCANFD_CSTS(ch));
1544 	bec->txerr = RCANFD_CSTS_TECCNT(val);
1545 	bec->rxerr = RCANFD_CSTS_RECCNT(val);
1546 	return 0;
1547 }
1548 
1549 static const struct net_device_ops rcar_canfd_netdev_ops = {
1550 	.ndo_open = rcar_canfd_open,
1551 	.ndo_stop = rcar_canfd_close,
1552 	.ndo_start_xmit = rcar_canfd_start_xmit,
1553 	.ndo_change_mtu = can_change_mtu,
1554 };
1555 
1556 static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch,
1557 				    u32 fcan_freq)
1558 {
1559 	struct platform_device *pdev = gpriv->pdev;
1560 	struct rcar_canfd_channel *priv;
1561 	struct net_device *ndev;
1562 	int err = -ENODEV;
1563 
1564 	ndev = alloc_candev(sizeof(*priv), RCANFD_FIFO_DEPTH);
1565 	if (!ndev) {
1566 		dev_err(&pdev->dev, "alloc_candev() failed\n");
1567 		err = -ENOMEM;
1568 		goto fail;
1569 	}
1570 	priv = netdev_priv(ndev);
1571 
1572 	ndev->netdev_ops = &rcar_canfd_netdev_ops;
1573 	ndev->flags |= IFF_ECHO;
1574 	priv->ndev = ndev;
1575 	priv->base = gpriv->base;
1576 	priv->channel = ch;
1577 	priv->can.clock.freq = fcan_freq;
1578 	dev_info(&pdev->dev, "can_clk rate is %u\n", priv->can.clock.freq);
1579 
1580 	if (gpriv->fdmode) {
1581 		priv->can.bittiming_const = &rcar_canfd_nom_bittiming_const;
1582 		priv->can.data_bittiming_const =
1583 			&rcar_canfd_data_bittiming_const;
1584 
1585 		/* Controller starts in CAN FD only mode */
1586 		can_set_static_ctrlmode(ndev, CAN_CTRLMODE_FD);
1587 		priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
1588 	} else {
1589 		/* Controller starts in Classical CAN only mode */
1590 		priv->can.bittiming_const = &rcar_canfd_bittiming_const;
1591 		priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
1592 	}
1593 
1594 	priv->can.do_set_mode = rcar_canfd_do_set_mode;
1595 	priv->can.do_get_berr_counter = rcar_canfd_get_berr_counter;
1596 	priv->gpriv = gpriv;
1597 	SET_NETDEV_DEV(ndev, &pdev->dev);
1598 
1599 	netif_napi_add(ndev, &priv->napi, rcar_canfd_rx_poll,
1600 		       RCANFD_NAPI_WEIGHT);
1601 	err = register_candev(ndev);
1602 	if (err) {
1603 		dev_err(&pdev->dev,
1604 			"register_candev() failed, error %d\n", err);
1605 		goto fail_candev;
1606 	}
1607 	spin_lock_init(&priv->tx_lock);
1608 	devm_can_led_init(ndev);
1609 	gpriv->ch[priv->channel] = priv;
1610 	dev_info(&pdev->dev, "device registered (channel %u)\n", priv->channel);
1611 	return 0;
1612 
1613 fail_candev:
1614 	netif_napi_del(&priv->napi);
1615 	free_candev(ndev);
1616 fail:
1617 	return err;
1618 }
1619 
1620 static void rcar_canfd_channel_remove(struct rcar_canfd_global *gpriv, u32 ch)
1621 {
1622 	struct rcar_canfd_channel *priv = gpriv->ch[ch];
1623 
1624 	if (priv) {
1625 		unregister_candev(priv->ndev);
1626 		netif_napi_del(&priv->napi);
1627 		free_candev(priv->ndev);
1628 	}
1629 }
1630 
1631 static int rcar_canfd_probe(struct platform_device *pdev)
1632 {
1633 	void __iomem *addr;
1634 	u32 sts, ch, fcan_freq;
1635 	struct rcar_canfd_global *gpriv;
1636 	struct device_node *of_child;
1637 	unsigned long channels_mask = 0;
1638 	int err, ch_irq, g_irq;
1639 	bool fdmode = true;			/* CAN FD only mode - default */
1640 
1641 	if (of_property_read_bool(pdev->dev.of_node, "renesas,no-can-fd"))
1642 		fdmode = false;			/* Classical CAN only mode */
1643 
1644 	of_child = of_get_child_by_name(pdev->dev.of_node, "channel0");
1645 	if (of_child && of_device_is_available(of_child))
1646 		channels_mask |= BIT(0);	/* Channel 0 */
1647 
1648 	of_child = of_get_child_by_name(pdev->dev.of_node, "channel1");
1649 	if (of_child && of_device_is_available(of_child))
1650 		channels_mask |= BIT(1);	/* Channel 1 */
1651 
1652 	ch_irq = platform_get_irq(pdev, 0);
1653 	if (ch_irq < 0) {
1654 		err = ch_irq;
1655 		goto fail_dev;
1656 	}
1657 
1658 	g_irq = platform_get_irq(pdev, 1);
1659 	if (g_irq < 0) {
1660 		err = g_irq;
1661 		goto fail_dev;
1662 	}
1663 
1664 	/* Global controller context */
1665 	gpriv = devm_kzalloc(&pdev->dev, sizeof(*gpriv), GFP_KERNEL);
1666 	if (!gpriv) {
1667 		err = -ENOMEM;
1668 		goto fail_dev;
1669 	}
1670 	gpriv->pdev = pdev;
1671 	gpriv->channels_mask = channels_mask;
1672 	gpriv->fdmode = fdmode;
1673 
1674 	/* Peripheral clock */
1675 	gpriv->clkp = devm_clk_get(&pdev->dev, "fck");
1676 	if (IS_ERR(gpriv->clkp)) {
1677 		err = PTR_ERR(gpriv->clkp);
1678 		dev_err(&pdev->dev, "cannot get peripheral clock, error %d\n",
1679 			err);
1680 		goto fail_dev;
1681 	}
1682 
1683 	/* fCAN clock: Pick External clock. If not available fallback to
1684 	 * CANFD clock
1685 	 */
1686 	gpriv->can_clk = devm_clk_get(&pdev->dev, "can_clk");
1687 	if (IS_ERR(gpriv->can_clk) || (clk_get_rate(gpriv->can_clk) == 0)) {
1688 		gpriv->can_clk = devm_clk_get(&pdev->dev, "canfd");
1689 		if (IS_ERR(gpriv->can_clk)) {
1690 			err = PTR_ERR(gpriv->can_clk);
1691 			dev_err(&pdev->dev,
1692 				"cannot get canfd clock, error %d\n", err);
1693 			goto fail_dev;
1694 		}
1695 		gpriv->fcan = RCANFD_CANFDCLK;
1696 
1697 	} else {
1698 		gpriv->fcan = RCANFD_EXTCLK;
1699 	}
1700 	fcan_freq = clk_get_rate(gpriv->can_clk);
1701 
1702 	if (gpriv->fcan == RCANFD_CANFDCLK)
1703 		/* CANFD clock is further divided by (1/2) within the IP */
1704 		fcan_freq /= 2;
1705 
1706 	addr = devm_platform_ioremap_resource(pdev, 0);
1707 	if (IS_ERR(addr)) {
1708 		err = PTR_ERR(addr);
1709 		goto fail_dev;
1710 	}
1711 	gpriv->base = addr;
1712 
1713 	/* Request IRQ that's common for both channels */
1714 	err = devm_request_irq(&pdev->dev, ch_irq,
1715 			       rcar_canfd_channel_interrupt, 0,
1716 			       "canfd.chn", gpriv);
1717 	if (err) {
1718 		dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
1719 			ch_irq, err);
1720 		goto fail_dev;
1721 	}
1722 	err = devm_request_irq(&pdev->dev, g_irq,
1723 			       rcar_canfd_global_interrupt, 0,
1724 			       "canfd.gbl", gpriv);
1725 	if (err) {
1726 		dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
1727 			g_irq, err);
1728 		goto fail_dev;
1729 	}
1730 
1731 	/* Enable peripheral clock for register access */
1732 	err = clk_prepare_enable(gpriv->clkp);
1733 	if (err) {
1734 		dev_err(&pdev->dev,
1735 			"failed to enable peripheral clock, error %d\n", err);
1736 		goto fail_dev;
1737 	}
1738 
1739 	err = rcar_canfd_reset_controller(gpriv);
1740 	if (err) {
1741 		dev_err(&pdev->dev, "reset controller failed\n");
1742 		goto fail_clk;
1743 	}
1744 
1745 	/* Controller in Global reset & Channel reset mode */
1746 	rcar_canfd_configure_controller(gpriv);
1747 
1748 	/* Configure per channel attributes */
1749 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
1750 		/* Configure Channel's Rx fifo */
1751 		rcar_canfd_configure_rx(gpriv, ch);
1752 
1753 		/* Configure Channel's Tx (Common) fifo */
1754 		rcar_canfd_configure_tx(gpriv, ch);
1755 
1756 		/* Configure receive rules */
1757 		rcar_canfd_configure_afl_rules(gpriv, ch);
1758 	}
1759 
1760 	/* Configure common interrupts */
1761 	rcar_canfd_enable_global_interrupts(gpriv);
1762 
1763 	/* Start Global operation mode */
1764 	rcar_canfd_update_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GMDC_MASK,
1765 			      RCANFD_GCTR_GMDC_GOPM);
1766 
1767 	/* Verify mode change */
1768 	err = readl_poll_timeout((gpriv->base + RCANFD_GSTS), sts,
1769 				 !(sts & RCANFD_GSTS_GNOPM), 2, 500000);
1770 	if (err) {
1771 		dev_err(&pdev->dev, "global operational mode failed\n");
1772 		goto fail_mode;
1773 	}
1774 
1775 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
1776 		err = rcar_canfd_channel_probe(gpriv, ch, fcan_freq);
1777 		if (err)
1778 			goto fail_channel;
1779 	}
1780 
1781 	platform_set_drvdata(pdev, gpriv);
1782 	dev_info(&pdev->dev, "global operational state (clk %d, fdmode %d)\n",
1783 		 gpriv->fcan, gpriv->fdmode);
1784 	return 0;
1785 
1786 fail_channel:
1787 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS)
1788 		rcar_canfd_channel_remove(gpriv, ch);
1789 fail_mode:
1790 	rcar_canfd_disable_global_interrupts(gpriv);
1791 fail_clk:
1792 	clk_disable_unprepare(gpriv->clkp);
1793 fail_dev:
1794 	return err;
1795 }
1796 
1797 static int rcar_canfd_remove(struct platform_device *pdev)
1798 {
1799 	struct rcar_canfd_global *gpriv = platform_get_drvdata(pdev);
1800 	u32 ch;
1801 
1802 	rcar_canfd_reset_controller(gpriv);
1803 	rcar_canfd_disable_global_interrupts(gpriv);
1804 
1805 	for_each_set_bit(ch, &gpriv->channels_mask, RCANFD_NUM_CHANNELS) {
1806 		rcar_canfd_disable_channel_interrupts(gpriv->ch[ch]);
1807 		rcar_canfd_channel_remove(gpriv, ch);
1808 	}
1809 
1810 	/* Enter global sleep mode */
1811 	rcar_canfd_set_bit(gpriv->base, RCANFD_GCTR, RCANFD_GCTR_GSLPR);
1812 	clk_disable_unprepare(gpriv->clkp);
1813 	return 0;
1814 }
1815 
1816 static int __maybe_unused rcar_canfd_suspend(struct device *dev)
1817 {
1818 	return 0;
1819 }
1820 
1821 static int __maybe_unused rcar_canfd_resume(struct device *dev)
1822 {
1823 	return 0;
1824 }
1825 
1826 static SIMPLE_DEV_PM_OPS(rcar_canfd_pm_ops, rcar_canfd_suspend,
1827 			 rcar_canfd_resume);
1828 
1829 static const struct of_device_id rcar_canfd_of_table[] = {
1830 	{ .compatible = "renesas,rcar-gen3-canfd" },
1831 	{ }
1832 };
1833 
1834 MODULE_DEVICE_TABLE(of, rcar_canfd_of_table);
1835 
1836 static struct platform_driver rcar_canfd_driver = {
1837 	.driver = {
1838 		.name = RCANFD_DRV_NAME,
1839 		.of_match_table = of_match_ptr(rcar_canfd_of_table),
1840 		.pm = &rcar_canfd_pm_ops,
1841 	},
1842 	.probe = rcar_canfd_probe,
1843 	.remove = rcar_canfd_remove,
1844 };
1845 
1846 module_platform_driver(rcar_canfd_driver);
1847 
1848 MODULE_AUTHOR("Ramesh Shanmugasundaram <ramesh.shanmugasundaram@bp.renesas.com>");
1849 MODULE_LICENSE("GPL");
1850 MODULE_DESCRIPTION("CAN FD driver for Renesas R-Car SoC");
1851 MODULE_ALIAS("platform:" RCANFD_DRV_NAME);
1852