xref: /linux/drivers/net/wan/framer/pef2256/pef2256.c (revision 55a42f78ffd386e01a5404419f8c5ded7db70a21)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PEF2256 also known as FALC56 driver
4  *
5  * Copyright 2023 CS GROUP France
6  *
7  * Author: Herve Codina <herve.codina@bootlin.com>
8  */
9 
10 #include <linux/framer/pef2256.h>
11 #include <linux/clk.h>
12 #include <linux/framer/framer-provider.h>
13 #include <linux/gpio/consumer.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/mfd/core.h>
17 #include <linux/module.h>
18 #include <linux/notifier.h>
19 #include <linux/of.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/regmap.h>
23 #include <linux/slab.h>
24 #include "pef2256-regs.h"
25 
26 enum pef2256_frame_type {
27 	PEF2256_FRAME_E1_DOUBLEFRAME,
28 	PEF2256_FRAME_E1_CRC4_MULTIFRAME,
29 	PEF2256_FRAME_E1_AUTO_MULTIFRAME,
30 	PEF2256_FRAME_T1J1_4FRAME,
31 	PEF2256_FRAME_T1J1_12FRAME,
32 	PEF2256_FRAME_T1J1_24FRAME,
33 	PEF2256_FRAME_T1J1_72FRAME,
34 };
35 
36 struct pef2256 {
37 	struct device *dev;
38 	struct regmap *regmap;
39 	enum pef2256_version version;
40 	const char *version_txt;
41 	struct clk *mclk;
42 	struct clk *sclkr;
43 	struct clk *sclkx;
44 	struct gpio_desc *reset_gpio;
45 	unsigned long sysclk_rate;
46 	u32 data_rate;
47 	bool is_tx_falling_edge;
48 	bool is_subordinate;
49 	enum pef2256_frame_type frame_type;
50 	u8 channel_phase;
51 	atomic_t carrier;
52 	struct framer *framer;
53 };
54 
55 static u8 pef2256_read8(struct pef2256 *pef2256, int offset)
56 {
57 	int val;
58 
59 	regmap_read(pef2256->regmap, offset, &val);
60 	return val;
61 }
62 
63 static void pef2256_write8(struct pef2256 *pef2256, int offset, u8 val)
64 {
65 	regmap_write(pef2256->regmap, offset, val);
66 }
67 
68 static void pef2256_clrbits8(struct pef2256 *pef2256, int offset, u8 clr)
69 {
70 	regmap_clear_bits(pef2256->regmap, offset, clr);
71 }
72 
73 static void pef2256_setbits8(struct pef2256 *pef2256, int offset, u8 set)
74 {
75 	regmap_set_bits(pef2256->regmap, offset, set);
76 }
77 
78 static void pef2256_clrsetbits8(struct pef2256 *pef2256, int offset, u8 clr, u8 set)
79 {
80 	regmap_update_bits(pef2256->regmap, offset, clr | set, set);
81 }
82 
83 enum pef2256_version pef2256_get_version(struct pef2256 *pef2256)
84 {
85 	enum pef2256_version version = PEF2256_VERSION_UNKNOWN;
86 	u8 vstr, wid;
87 
88 	vstr = pef2256_read8(pef2256, PEF2256_VSTR);
89 	wid = pef2256_read8(pef2256, PEF2256_WID);
90 
91 	switch (vstr) {
92 	case PEF2256_VSTR_VERSION_12:
93 		if ((wid & PEF2256_12_WID_MASK) == PEF2256_12_WID_VERSION_12)
94 			version = PEF2256_VERSION_1_2;
95 		break;
96 	case PEF2256_VSTR_VERSION_2x:
97 		switch (wid & PEF2256_2X_WID_MASK) {
98 		case PEF2256_2X_WID_VERSION_21:
99 			version = PEF2256_VERSION_2_1;
100 			break;
101 		case PEF2256_2X_WID_VERSION_22:
102 			version = PEF2256_VERSION_2_2;
103 			break;
104 		}
105 		break;
106 	case PEF2256_VSTR_VERSION_21:
107 		version = PEF2256_VERSION_2_1;
108 		break;
109 	}
110 
111 	if (version == PEF2256_VERSION_UNKNOWN)
112 		dev_err(pef2256->dev, "Unknown version (0x%02x, 0x%02x)\n", vstr, wid);
113 
114 	return version;
115 }
116 EXPORT_SYMBOL_GPL(pef2256_get_version);
117 
118 static ssize_t version_show(struct device *dev, struct device_attribute *attr,
119 			    char *buf)
120 {
121 	struct pef2256 *pef2256 = dev_get_drvdata(dev);
122 
123 	return sysfs_emit(buf, "%s\n", pef2256->version_txt);
124 }
125 
126 static DEVICE_ATTR_RO(version);
127 
128 enum pef2256_gcm_config_item {
129 	PEF2256_GCM_CONFIG_1544000 = 0,
130 	PEF2256_GCM_CONFIG_2048000,
131 	PEF2256_GCM_CONFIG_8192000,
132 	PEF2256_GCM_CONFIG_10000000,
133 	PEF2256_GCM_CONFIG_12352000,
134 	PEF2256_GCM_CONFIG_16384000,
135 };
136 
137 struct pef2256_gcm_config {
138 	u8 gcm_12[6];
139 	u8 gcm_2x[8];
140 };
141 
142 static const struct pef2256_gcm_config pef2256_gcm_configs[] = {
143 	[PEF2256_GCM_CONFIG_1544000] = {
144 		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x00, 0x15},
145 		.gcm_2x = {0x00, 0x15, 0x00, 0x08, 0x00, 0x3F, 0x9C, 0xDF},
146 	},
147 	[PEF2256_GCM_CONFIG_2048000] = {
148 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x00, 0x10},
149 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x2F, 0xDB, 0xDF},
150 	},
151 	[PEF2256_GCM_CONFIG_8192000] = {
152 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x03, 0x10},
153 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x0B, 0xDB, 0xDF},
154 	},
155 	[PEF2256_GCM_CONFIG_10000000] = {
156 		.gcm_12 = {0x90, 0x51, 0x81, 0x8F, 0x04, 0x10},
157 		.gcm_2x = {0x40, 0x1B, 0x3D, 0x0A, 0x00, 0x07, 0xC9, 0xDC},
158 	},
159 	[PEF2256_GCM_CONFIG_12352000] = {
160 		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x07, 0x15},
161 		.gcm_2x = {0x00, 0x19, 0x00, 0x08, 0x01, 0x0A, 0x98, 0xDA},
162 	},
163 	[PEF2256_GCM_CONFIG_16384000] = {
164 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x07, 0x10},
165 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x01, 0x0B, 0xDB, 0xDF},
166 	},
167 };
168 
169 static int pef2256_setup_gcm(struct pef2256 *pef2256)
170 {
171 	enum pef2256_gcm_config_item item;
172 	unsigned long mclk_rate;
173 	const u8 *gcm;
174 	int i, count;
175 
176 	mclk_rate = clk_get_rate(pef2256->mclk);
177 	switch (mclk_rate) {
178 	case 1544000:
179 		item = PEF2256_GCM_CONFIG_1544000;
180 		break;
181 	case 2048000:
182 		item = PEF2256_GCM_CONFIG_2048000;
183 		break;
184 	case 8192000:
185 		item = PEF2256_GCM_CONFIG_8192000;
186 		break;
187 	case 10000000:
188 		item = PEF2256_GCM_CONFIG_10000000;
189 		break;
190 	case 12352000:
191 		item = PEF2256_GCM_CONFIG_12352000;
192 		break;
193 	case 16384000:
194 		item = PEF2256_GCM_CONFIG_16384000;
195 		break;
196 	default:
197 		dev_err(pef2256->dev, "Unsupported v2.x MCLK rate %lu\n", mclk_rate);
198 		return -EINVAL;
199 	}
200 
201 	BUILD_BUG_ON(item >= ARRAY_SIZE(pef2256_gcm_configs));
202 
203 	if (pef2256->version == PEF2256_VERSION_1_2) {
204 		gcm = pef2256_gcm_configs[item].gcm_12;
205 		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_12);
206 	} else {
207 		gcm = pef2256_gcm_configs[item].gcm_2x;
208 		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_2x);
209 	}
210 
211 	for (i = 0; i < count; i++)
212 		pef2256_write8(pef2256, PEF2256_GCM(i + 1), *(gcm + i));
213 
214 	return 0;
215 }
216 
217 static int pef2256_setup_e1_line(struct pef2256 *pef2256)
218 {
219 	u8 fmr1, fmr2;
220 
221 	/* RCLK output : DPLL clock, DCO-X enabled, DCO-X internal ref clock */
222 	pef2256_write8(pef2256, PEF2256_CMR1, 0x00);
223 
224 	/* SCLKR selected, SCLKX selected,
225 	 * receive synchro pulse sourced by SYPR,
226 	 * transmit synchro pulse sourced by SYPX,
227 	 * DCO-X center frequency enabled
228 	 */
229 	pef2256_write8(pef2256, PEF2256_CMR2, PEF2256_CMR2_DCOXC);
230 
231 	if (pef2256->is_subordinate) {
232 		/* select RCLK source = 2M,  disable switching from RCLK to SYNC */
233 		pef2256_clrsetbits8(pef2256, PEF2256_CMR1, PEF2256_CMR1_RS_MASK,
234 				    PEF2256_CMR1_RS_DCOR_2048 | PEF2256_CMR1_DCS);
235 	}
236 
237 	/* slave mode, local loop off, mode short-haul
238 	 * In v2.x, bit3 is a forced 1 bit in the datasheet -> Need to be set.
239 	 */
240 	if (pef2256->version == PEF2256_VERSION_1_2)
241 		pef2256_write8(pef2256, PEF2256_LIM0, 0x00);
242 	else
243 		pef2256_write8(pef2256, PEF2256_LIM0, PEF2256_2X_LIM0_BIT3);
244 
245 	/* "master" mode */
246 	if (!pef2256->is_subordinate)
247 		pef2256_setbits8(pef2256, PEF2256_LIM0, PEF2256_LIM0_MAS);
248 
249 	/* analog interface selected, remote loop off */
250 	pef2256_write8(pef2256, PEF2256_LIM1, 0x00);
251 
252 	/* receive input threshold = 0,21V */
253 	if (pef2256->version == PEF2256_VERSION_1_2)
254 		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_12_LIM1_RIL_MASK,
255 				    PEF2256_12_LIM1_RIL_210);
256 	else
257 		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_2X_LIM1_RIL_MASK,
258 				    PEF2256_2X_LIM1_RIL_210);
259 
260 	/* transmit pulse mask, default value from datasheet
261 	 * transmit line in normal operation
262 	 */
263 	if (pef2256->version == PEF2256_VERSION_1_2)
264 		pef2256_write8(pef2256, PEF2256_XPM0, 0x7B);
265 	else
266 		pef2256_write8(pef2256, PEF2256_XPM0, 0x9C);
267 	pef2256_write8(pef2256, PEF2256_XPM1, 0x03);
268 	pef2256_write8(pef2256, PEF2256_XPM2, 0x00);
269 
270 	/* HDB3 coding, no alarm simulation */
271 	pef2256_write8(pef2256, PEF2256_FMR0, PEF2256_FMR0_XC_HDB3 | PEF2256_FMR0_RC_HDB3);
272 
273 	/* E1, frame format, 2 Mbit/s system data rate, no AIS
274 	 * transmission to remote end or system interface, payload loop
275 	 * off, transmit remote alarm on
276 	 */
277 	fmr1 = 0x00;
278 	fmr2 = PEF2256_FMR2_AXRA;
279 	switch (pef2256->frame_type) {
280 	case PEF2256_FRAME_E1_DOUBLEFRAME:
281 		fmr2 |= PEF2256_FMR2_RFS_DOUBLEFRAME;
282 		break;
283 	case PEF2256_FRAME_E1_CRC4_MULTIFRAME:
284 		fmr1 |= PEF2256_FMR1_XFS;
285 		fmr2 |= PEF2256_FMR2_RFS_CRC4_MULTIFRAME;
286 		break;
287 	case PEF2256_FRAME_E1_AUTO_MULTIFRAME:
288 		fmr1 |= PEF2256_FMR1_XFS;
289 		fmr2 |= PEF2256_FMR2_RFS_AUTO_MULTIFRAME;
290 		break;
291 	default:
292 		dev_err(pef2256->dev, "Unsupported frame type %d\n", pef2256->frame_type);
293 		return -EINVAL;
294 	}
295 	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_XFS, fmr1);
296 	pef2256_write8(pef2256, PEF2256_FMR2, fmr2);
297 
298 	if (!pef2256->is_subordinate) {
299 		/* SEC input, active high */
300 		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_SEC_IN_HIGH);
301 	} else {
302 		/* FSC output, active high */
303 		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_FSC_OUT_HIGH);
304 	}
305 
306 	/* SCLKR, SCLKX, RCLK configured to inputs,
307 	 * XFMS active low, CLK1 and CLK2 pin configuration
308 	 */
309 	pef2256_write8(pef2256, PEF2256_PC5, 0x00);
310 	pef2256_write8(pef2256, PEF2256_PC6, 0x00);
311 
312 	/* port RCLK is output */
313 	pef2256_setbits8(pef2256, PEF2256_PC5, PEF2256_PC5_CRP);
314 
315 	return 0;
316 }
317 
318 static void pef2256_setup_e1_los(struct pef2256 *pef2256)
319 {
320 	/* detection of LOS alarm = 176 pulses (ie (10 + 1) * 16) */
321 	pef2256_write8(pef2256, PEF2256_PCD, 10);
322 	/* recovery of LOS alarm = 22 pulses (ie 21 + 1) */
323 	pef2256_write8(pef2256, PEF2256_PCR, 21);
324 	/* E1 default for the receive slicer threshold */
325 	pef2256_write8(pef2256, PEF2256_LIM2, PEF2256_LIM2_SLT_THR50);
326 	if (pef2256->is_subordinate) {
327 		/* Loop-timed */
328 		pef2256_setbits8(pef2256, PEF2256_LIM2, PEF2256_LIM2_ELT);
329 	}
330 }
331 
332 static int pef2256_setup_e1_system(struct pef2256 *pef2256)
333 {
334 	u8 sic1, fmr1;
335 
336 	/* 2.048 MHz system clocking rate, receive buffer 2 frames, transmit
337 	 * buffer bypass, data sampled and transmitted on the falling edge of
338 	 * SCLKR/X, automatic freeze signaling, data is active in the first
339 	 * channel phase
340 	 */
341 	pef2256_write8(pef2256, PEF2256_SIC1, 0x00);
342 	pef2256_write8(pef2256, PEF2256_SIC2, 0x00);
343 	pef2256_write8(pef2256, PEF2256_SIC3, 0x00);
344 
345 	if (pef2256->is_subordinate) {
346 		/* transmit buffer size = 2 frames, transparent mode */
347 		pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_XBS_MASK,
348 				    PEF2256_SIC1_XBS_2FRAMES);
349 	}
350 
351 	if (pef2256->version != PEF2256_VERSION_1_2) {
352 		/* during inactive channel phase switch RDO/RSIG into tri-state */
353 		pef2256_setbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RTRI);
354 	}
355 
356 	if (pef2256->is_tx_falling_edge) {
357 		/* falling edge sync pulse transmit, rising edge sync pulse receive */
358 		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESX, PEF2256_SIC3_RESR);
359 	} else {
360 		/* rising edge sync pulse transmit, falling edge sync pulse receive */
361 		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESR, PEF2256_SIC3_RESX);
362 	}
363 
364 	/* transmit offset counter (XCO10..0) = 4 */
365 	pef2256_write8(pef2256, PEF2256_XC0, 0);
366 	pef2256_write8(pef2256, PEF2256_XC1, 4);
367 	/* receive offset counter (RCO10..0) = 4 */
368 	pef2256_write8(pef2256, PEF2256_RC0, 0);
369 	pef2256_write8(pef2256, PEF2256_RC1, 4);
370 
371 	/* system clock rate */
372 	switch (pef2256->sysclk_rate) {
373 	case 2048000:
374 		sic1 = PEF2256_SIC1_SSC_2048;
375 		break;
376 	case 4096000:
377 		sic1 = PEF2256_SIC1_SSC_4096;
378 		break;
379 	case 8192000:
380 		sic1 = PEF2256_SIC1_SSC_8192;
381 		break;
382 	case 16384000:
383 		sic1 = PEF2256_SIC1_SSC_16384;
384 		break;
385 	default:
386 		dev_err(pef2256->dev, "Unsupported sysclk rate %lu\n", pef2256->sysclk_rate);
387 		return -EINVAL;
388 	}
389 	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSC_MASK, sic1);
390 
391 	/* data clock rate */
392 	switch (pef2256->data_rate) {
393 	case 2048000:
394 		fmr1 = PEF2256_FMR1_SSD_2048;
395 		sic1 = PEF2256_SIC1_SSD_2048;
396 		break;
397 	case 4096000:
398 		fmr1 = PEF2256_FMR1_SSD_4096;
399 		sic1 = PEF2256_SIC1_SSD_4096;
400 		break;
401 	case 8192000:
402 		fmr1 = PEF2256_FMR1_SSD_8192;
403 		sic1 = PEF2256_SIC1_SSD_8192;
404 		break;
405 	case 16384000:
406 		fmr1 = PEF2256_FMR1_SSD_16384;
407 		sic1 = PEF2256_SIC1_SSD_16384;
408 		break;
409 	default:
410 		dev_err(pef2256->dev, "Unsupported data rate %u\n", pef2256->data_rate);
411 		return -EINVAL;
412 	}
413 	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_SSD_MASK, fmr1);
414 	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSD_MASK, sic1);
415 
416 	/* channel phase */
417 	pef2256_clrsetbits8(pef2256, PEF2256_SIC2, PEF2256_SIC2_SICS_MASK,
418 			    PEF2256_SIC2_SICS(pef2256->channel_phase));
419 
420 	return 0;
421 }
422 
423 static void pef2256_setup_e1_signaling(struct pef2256 *pef2256)
424 {
425 	/* All bits of the transmitted service word are cleared */
426 	pef2256_write8(pef2256, PEF2256_XSW, PEF2256_XSW_XY(0x1F));
427 
428 	/* CAS disabled and clear spare bit values */
429 	pef2256_write8(pef2256, PEF2256_XSP, 0x00);
430 
431 	if (pef2256->is_subordinate) {
432 		/* transparent mode */
433 		pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XTM);
434 	}
435 
436 	/* Si-Bit, Spare bit For International, FAS word */
437 	pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XSIS);
438 	pef2256_setbits8(pef2256, PEF2256_XSP, PEF2256_XSP_XSIF);
439 
440 	/* no transparent mode active */
441 	pef2256_write8(pef2256, PEF2256_TSWM, 0x00);
442 }
443 
444 static void pef2256_setup_e1_errors(struct pef2256 *pef2256)
445 {
446 	/* error counter latched every 1s */
447 	pef2256_setbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_ECM);
448 
449 	/* error counter mode COFA */
450 	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_ECMC);
451 
452 	/* errors in service words have no influence */
453 	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_SWD);
454 
455 	/* 4 consecutive incorrect FAS causes loss of sync */
456 	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_ASY4);
457 }
458 
459 static int pef2256_setup_e1(struct pef2256 *pef2256)
460 {
461 	int ret;
462 
463 	/* Setup, Master clocking mode (GCM8..1) */
464 	ret = pef2256_setup_gcm(pef2256);
465 	if (ret)
466 		return ret;
467 
468 	/* Select E1 mode */
469 	pef2256_write8(pef2256, PEF2256_FMR1, 0x00);
470 
471 	/* internal second timer, power on */
472 	pef2256_write8(pef2256, PEF2256_GCR, 0x00);
473 
474 	/* Setup line interface */
475 	ret = pef2256_setup_e1_line(pef2256);
476 	if (ret)
477 		return ret;
478 
479 	/* Setup Loss-of-signal detection and recovery */
480 	pef2256_setup_e1_los(pef2256);
481 
482 	/* Setup system interface */
483 	ret = pef2256_setup_e1_system(pef2256);
484 	if (ret)
485 		return ret;
486 
487 	/* Setup signaling */
488 	pef2256_setup_e1_signaling(pef2256);
489 
490 	/* Setup errors counters and condition */
491 	pef2256_setup_e1_errors(pef2256);
492 
493 	/* status changed interrupt at both up and down */
494 	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_SCI);
495 
496 	/* Clear any ISR2 pending interrupts and unmask needed interrupts */
497 	pef2256_read8(pef2256, PEF2256_ISR2);
498 	pef2256_clrbits8(pef2256, PEF2256_IMR2, PEF2256_INT2_LOS | PEF2256_INT2_AIS);
499 
500 	/* reset lines */
501 	pef2256_write8(pef2256, PEF2256_CMDR, PEF2256_CMDR_RRES | PEF2256_CMDR_XRES);
502 	return 0;
503 }
504 
505 static void pef2256_isr_default_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
506 {
507 	dev_warn_ratelimited(pef2256->dev, "ISR%u: 0x%02x not handled\n", nbr, isr);
508 }
509 
510 static bool pef2256_is_carrier_on(struct pef2256 *pef2256)
511 {
512 	u8 frs0;
513 
514 	frs0 = pef2256_read8(pef2256, PEF2256_FRS0);
515 	return !(frs0 & (PEF2256_FRS0_LOS | PEF2256_FRS0_AIS));
516 }
517 
518 static void pef2256_isr2_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
519 {
520 	bool carrier;
521 
522 	if (isr & (PEF2256_INT2_LOS | PEF2256_INT2_AIS)) {
523 		carrier = pef2256_is_carrier_on(pef2256);
524 		if (atomic_xchg(&pef2256->carrier, carrier) != carrier)
525 			framer_notify_status_change(pef2256->framer);
526 	}
527 }
528 
529 static irqreturn_t pef2256_irq_handler(int irq, void *priv)
530 {
531 	static void (*pef2256_isr_handler[])(struct pef2256 *, u8, u8) = {
532 		[0] = pef2256_isr_default_handler,
533 		[1] = pef2256_isr_default_handler,
534 		[2] = pef2256_isr2_handler,
535 		[3] = pef2256_isr_default_handler,
536 		[4] = pef2256_isr_default_handler,
537 		[5] = pef2256_isr_default_handler
538 	};
539 	struct pef2256 *pef2256 = (struct pef2256 *)priv;
540 	u8 gis;
541 	u8 isr;
542 	u8 n;
543 
544 	gis = pef2256_read8(pef2256, PEF2256_GIS);
545 
546 	for (n = 0; n < ARRAY_SIZE(pef2256_isr_handler); n++) {
547 		if (gis & PEF2256_GIS_ISR(n)) {
548 			isr = pef2256_read8(pef2256, PEF2256_ISR(n));
549 			pef2256_isr_handler[n](pef2256, n, isr);
550 		}
551 	}
552 
553 	return IRQ_HANDLED;
554 }
555 
556 static int pef2256_check_rates(struct pef2256 *pef2256, unsigned long sysclk_rate,
557 			       unsigned long data_rate)
558 {
559 	unsigned long rate;
560 
561 	switch (sysclk_rate) {
562 	case 2048000:
563 	case 4096000:
564 	case 8192000:
565 	case 16384000:
566 		break;
567 	default:
568 		dev_err(pef2256->dev, "Unsupported system clock rate %lu\n", sysclk_rate);
569 		return -EINVAL;
570 	}
571 
572 	for (rate = data_rate; rate <= data_rate * 4; rate *= 2) {
573 		if (rate == sysclk_rate)
574 			return 0;
575 	}
576 	dev_err(pef2256->dev, "Unsupported data rate %lu with system clock rate %lu\n",
577 		data_rate, sysclk_rate);
578 	return -EINVAL;
579 }
580 
581 static int pef2556_of_parse(struct pef2256 *pef2256, struct device_node *np)
582 {
583 	int ret;
584 
585 	pef2256->data_rate = 2048000;
586 	ret = of_property_read_u32(np, "lantiq,data-rate-bps", &pef2256->data_rate);
587 	if (ret && ret != -EINVAL) {
588 		dev_err(pef2256->dev, "%pOF: failed to read lantiq,data-rate-bps\n", np);
589 		return ret;
590 	}
591 
592 	ret =  pef2256_check_rates(pef2256, pef2256->sysclk_rate, pef2256->data_rate);
593 	if (ret)
594 		return ret;
595 
596 	pef2256->is_tx_falling_edge = of_property_read_bool(np, "lantiq,clock-falling-edge");
597 
598 	pef2256->channel_phase = 0;
599 	ret = of_property_read_u8(np, "lantiq,channel-phase", &pef2256->channel_phase);
600 	if (ret && ret != -EINVAL) {
601 		dev_err(pef2256->dev, "%pOF: failed to read lantiq,channel-phase\n",
602 			np);
603 		return ret;
604 	}
605 	if (pef2256->channel_phase >= pef2256->sysclk_rate / pef2256->data_rate) {
606 		dev_err(pef2256->dev, "%pOF: Invalid lantiq,channel-phase %u\n",
607 			np, pef2256->channel_phase);
608 		return -EINVAL;
609 	}
610 
611 	return 0;
612 }
613 
614 static const struct regmap_config pef2256_regmap_config = {
615 	.reg_bits = 32,
616 	.val_bits = 8,
617 	.max_register = 0xff,
618 };
619 
620 static const struct mfd_cell pef2256_devs[] = {
621 	{ .name = "lantiq-pef2256-pinctrl", },
622 };
623 
624 static int pef2256_add_audio_devices(struct pef2256 *pef2256)
625 {
626 	const char *compatible = "lantiq,pef2256-codec";
627 	struct mfd_cell *audio_devs;
628 	struct device_node *np;
629 	unsigned int count = 0;
630 	unsigned int i;
631 	int ret;
632 
633 	for_each_available_child_of_node(pef2256->dev->of_node, np) {
634 		if (of_device_is_compatible(np, compatible))
635 			count++;
636 	}
637 
638 	if (!count)
639 		return 0;
640 
641 	audio_devs = kcalloc(count, sizeof(*audio_devs), GFP_KERNEL);
642 	if (!audio_devs)
643 		return -ENOMEM;
644 
645 	for (i = 0; i < count; i++) {
646 		audio_devs[i].name = "framer-codec";
647 		audio_devs[i].of_compatible = compatible;
648 		audio_devs[i].id = i;
649 	}
650 
651 	ret = mfd_add_devices(pef2256->dev, 0, audio_devs, count, NULL, 0, NULL);
652 	kfree(audio_devs);
653 	return ret;
654 }
655 
656 static int pef2256_framer_get_status(struct framer *framer, struct framer_status *status)
657 {
658 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
659 
660 	status->link_is_on = !!atomic_read(&pef2256->carrier);
661 	return 0;
662 }
663 
664 static int pef2256_framer_set_config(struct framer *framer, const struct framer_config *config)
665 {
666 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
667 
668 	if (config->iface != FRAMER_IFACE_E1) {
669 		dev_err(pef2256->dev, "Only E1 line is currently supported\n");
670 		return -EOPNOTSUPP;
671 	}
672 
673 	switch (config->clock_type) {
674 	case FRAMER_CLOCK_EXT:
675 		pef2256->is_subordinate = true;
676 		break;
677 	case FRAMER_CLOCK_INT:
678 		pef2256->is_subordinate = false;
679 		break;
680 	default:
681 		return -EINVAL;
682 	}
683 
684 	/* Apply the new settings */
685 	return pef2256_setup_e1(pef2256);
686 }
687 
688 static int pef2256_framer_get_config(struct framer *framer, struct framer_config *config)
689 {
690 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
691 
692 	config->iface = FRAMER_IFACE_E1;
693 	config->clock_type = pef2256->is_subordinate ? FRAMER_CLOCK_EXT : FRAMER_CLOCK_INT;
694 	config->line_clock_rate = 2048000;
695 	return 0;
696 }
697 
698 static const struct framer_ops pef2256_framer_ops = {
699 	.owner = THIS_MODULE,
700 	.get_status = pef2256_framer_get_status,
701 	.get_config = pef2256_framer_get_config,
702 	.set_config = pef2256_framer_set_config,
703 };
704 
705 static int pef2256_probe(struct platform_device *pdev)
706 {
707 	struct device_node *np = pdev->dev.of_node;
708 	unsigned long sclkr_rate, sclkx_rate;
709 	struct framer_provider *framer_provider;
710 	struct pef2256 *pef2256;
711 	void __iomem *iomem;
712 	int ret;
713 	int irq;
714 
715 	pef2256 = devm_kzalloc(&pdev->dev, sizeof(*pef2256), GFP_KERNEL);
716 	if (!pef2256)
717 		return -ENOMEM;
718 
719 	pef2256->dev = &pdev->dev;
720 	atomic_set(&pef2256->carrier, 0);
721 
722 	pef2256->is_subordinate = true;
723 	pef2256->frame_type = PEF2256_FRAME_E1_DOUBLEFRAME;
724 
725 	iomem = devm_platform_ioremap_resource(pdev, 0);
726 	if (IS_ERR(iomem))
727 		return PTR_ERR(iomem);
728 
729 	pef2256->regmap = devm_regmap_init_mmio(&pdev->dev, iomem,
730 						&pef2256_regmap_config);
731 	if (IS_ERR(pef2256->regmap)) {
732 		dev_err(&pdev->dev, "Failed to initialise Regmap (%pe)\n",
733 			pef2256->regmap);
734 		return PTR_ERR(pef2256->regmap);
735 	}
736 
737 	pef2256->mclk = devm_clk_get_enabled(&pdev->dev, "mclk");
738 	if (IS_ERR(pef2256->mclk))
739 		return PTR_ERR(pef2256->mclk);
740 
741 	pef2256->sclkr = devm_clk_get_enabled(&pdev->dev, "sclkr");
742 	if (IS_ERR(pef2256->sclkr))
743 		return PTR_ERR(pef2256->sclkr);
744 
745 	pef2256->sclkx = devm_clk_get_enabled(&pdev->dev, "sclkx");
746 	if (IS_ERR(pef2256->sclkx))
747 		return PTR_ERR(pef2256->sclkx);
748 
749 	/* Both SCLKR (receive) and SCLKX (transmit) must have the same rate,
750 	 * stored as sysclk_rate.
751 	 * The exact value will be checked at pef2256_check_rates()
752 	 */
753 	sclkr_rate = clk_get_rate(pef2256->sclkr);
754 	sclkx_rate = clk_get_rate(pef2256->sclkx);
755 	if (sclkr_rate != sclkx_rate) {
756 		dev_err(pef2256->dev, "clk rate mismatch. sclkr %lu Hz, sclkx %lu Hz\n",
757 			sclkr_rate, sclkx_rate);
758 		return -EINVAL;
759 	}
760 	pef2256->sysclk_rate = sclkr_rate;
761 
762 	/* Reset the component. The MCLK clock must be active during reset */
763 	pef2256->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
764 	if (IS_ERR(pef2256->reset_gpio))
765 		return PTR_ERR(pef2256->reset_gpio);
766 	if (pef2256->reset_gpio) {
767 		gpiod_set_value_cansleep(pef2256->reset_gpio, 1);
768 		usleep_range(10, 20);
769 		gpiod_set_value_cansleep(pef2256->reset_gpio, 0);
770 		usleep_range(10, 20);
771 	}
772 
773 	pef2256->version = pef2256_get_version(pef2256);
774 	switch (pef2256->version) {
775 	case PEF2256_VERSION_1_2:
776 		pef2256->version_txt = "1.2";
777 		break;
778 	case PEF2256_VERSION_2_1:
779 		pef2256->version_txt = "2.1";
780 		break;
781 	case PEF2256_VERSION_2_2:
782 		pef2256->version_txt = "2.2";
783 		break;
784 	default:
785 		return -ENODEV;
786 	}
787 	dev_info(pef2256->dev, "Version %s detected\n", pef2256->version_txt);
788 
789 	ret = pef2556_of_parse(pef2256, np);
790 	if (ret)
791 		return ret;
792 
793 	/* Create the framer. It can be used on interrupts */
794 	pef2256->framer = devm_framer_create(pef2256->dev, NULL, &pef2256_framer_ops);
795 	if (IS_ERR(pef2256->framer))
796 		return PTR_ERR(pef2256->framer);
797 
798 	framer_set_drvdata(pef2256->framer, pef2256);
799 
800 	/* Disable interrupts */
801 	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
802 	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
803 	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
804 	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
805 	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
806 	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
807 
808 	/* Clear any pending interrupts */
809 	pef2256_read8(pef2256, PEF2256_ISR0);
810 	pef2256_read8(pef2256, PEF2256_ISR1);
811 	pef2256_read8(pef2256, PEF2256_ISR2);
812 	pef2256_read8(pef2256, PEF2256_ISR3);
813 	pef2256_read8(pef2256, PEF2256_ISR4);
814 	pef2256_read8(pef2256, PEF2256_ISR5);
815 
816 	irq = platform_get_irq(pdev, 0);
817 	if (irq < 0)
818 		return irq;
819 	ret = devm_request_irq(pef2256->dev, irq, pef2256_irq_handler, 0, "pef2256", pef2256);
820 	if (ret < 0)
821 		return ret;
822 
823 	platform_set_drvdata(pdev, pef2256);
824 
825 	ret = mfd_add_devices(pef2256->dev, 0, pef2256_devs,
826 			      ARRAY_SIZE(pef2256_devs), NULL, 0, NULL);
827 	if (ret) {
828 		dev_err(pef2256->dev, "add devices failed (%d)\n", ret);
829 		return ret;
830 	}
831 
832 	ret = pef2256_setup_e1(pef2256);
833 	if (ret)
834 		return ret;
835 
836 	framer_provider = devm_framer_provider_of_register(pef2256->dev,
837 							   framer_provider_simple_of_xlate);
838 	if (IS_ERR(framer_provider))
839 		return PTR_ERR(framer_provider);
840 
841 	/* Add audio devices */
842 	ret = pef2256_add_audio_devices(pef2256);
843 	if (ret < 0) {
844 		dev_err(pef2256->dev, "add audio devices failed (%d)\n", ret);
845 		return ret;
846 	}
847 
848 	device_create_file(pef2256->dev, &dev_attr_version);
849 
850 	return 0;
851 }
852 
853 static void pef2256_remove(struct platform_device *pdev)
854 {
855 	struct pef2256 *pef2256 = platform_get_drvdata(pdev);
856 
857 	/* Disable interrupts */
858 	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
859 	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
860 	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
861 	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
862 	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
863 	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
864 
865 	device_remove_file(pef2256->dev, &dev_attr_version);
866 }
867 
868 static const struct of_device_id pef2256_id_table[] = {
869 	{ .compatible = "lantiq,pef2256" },
870 	{} /* sentinel */
871 };
872 MODULE_DEVICE_TABLE(of, pef2256_id_table);
873 
874 static struct platform_driver pef2256_driver = {
875 	.driver = {
876 		.name = "lantiq-pef2256",
877 		.of_match_table = pef2256_id_table,
878 	},
879 	.probe = pef2256_probe,
880 	.remove = pef2256_remove,
881 };
882 module_platform_driver(pef2256_driver);
883 
884 struct regmap *pef2256_get_regmap(struct pef2256 *pef2256)
885 {
886 	return pef2256->regmap;
887 }
888 EXPORT_SYMBOL_GPL(pef2256_get_regmap);
889 
890 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
891 MODULE_DESCRIPTION("PEF2256 driver");
892 MODULE_LICENSE("GPL");
893