xref: /linux/drivers/net/wan/framer/pef2256/pef2256.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 	struct clk *mclk;
41 	struct clk *sclkr;
42 	struct clk *sclkx;
43 	struct gpio_desc *reset_gpio;
44 	unsigned long sysclk_rate;
45 	u32 data_rate;
46 	bool is_tx_falling_edge;
47 	bool is_subordinate;
48 	enum pef2256_frame_type frame_type;
49 	u8 channel_phase;
50 	atomic_t carrier;
51 	struct framer *framer;
52 };
53 
54 static u8 pef2256_read8(struct pef2256 *pef2256, int offset)
55 {
56 	int val;
57 
58 	regmap_read(pef2256->regmap, offset, &val);
59 	return val;
60 }
61 
62 static void pef2256_write8(struct pef2256 *pef2256, int offset, u8 val)
63 {
64 	regmap_write(pef2256->regmap, offset, val);
65 }
66 
67 static void pef2256_clrbits8(struct pef2256 *pef2256, int offset, u8 clr)
68 {
69 	regmap_clear_bits(pef2256->regmap, offset, clr);
70 }
71 
72 static void pef2256_setbits8(struct pef2256 *pef2256, int offset, u8 set)
73 {
74 	regmap_set_bits(pef2256->regmap, offset, set);
75 }
76 
77 static void pef2256_clrsetbits8(struct pef2256 *pef2256, int offset, u8 clr, u8 set)
78 {
79 	regmap_update_bits(pef2256->regmap, offset, clr | set, set);
80 }
81 
82 enum pef2256_version pef2256_get_version(struct pef2256 *pef2256)
83 {
84 	enum pef2256_version version = PEF2256_VERSION_UNKNOWN;
85 	u8 vstr, wid;
86 
87 	vstr = pef2256_read8(pef2256, PEF2256_VSTR);
88 	wid = pef2256_read8(pef2256, PEF2256_WID);
89 
90 	switch (vstr) {
91 	case PEF2256_VSTR_VERSION_12:
92 		if ((wid & PEF2256_12_WID_MASK) == PEF2256_12_WID_VERSION_12)
93 			version = PEF2256_VERSION_1_2;
94 		break;
95 	case PEF2256_VSTR_VERSION_2x:
96 		switch (wid & PEF2256_2X_WID_MASK) {
97 		case PEF2256_2X_WID_VERSION_21:
98 			version = PEF2256_VERSION_2_1;
99 			break;
100 		case PEF2256_2X_WID_VERSION_22:
101 			version = PEF2256_VERSION_2_2;
102 			break;
103 		}
104 		break;
105 	case PEF2256_VSTR_VERSION_21:
106 		version = PEF2256_VERSION_2_1;
107 		break;
108 	}
109 
110 	if (version == PEF2256_VERSION_UNKNOWN)
111 		dev_err(pef2256->dev, "Unknown version (0x%02x, 0x%02x)\n", vstr, wid);
112 
113 	return version;
114 }
115 EXPORT_SYMBOL_GPL(pef2256_get_version);
116 
117 enum pef2256_gcm_config_item {
118 	PEF2256_GCM_CONFIG_1544000 = 0,
119 	PEF2256_GCM_CONFIG_2048000,
120 	PEF2256_GCM_CONFIG_8192000,
121 	PEF2256_GCM_CONFIG_10000000,
122 	PEF2256_GCM_CONFIG_12352000,
123 	PEF2256_GCM_CONFIG_16384000,
124 };
125 
126 struct pef2256_gcm_config {
127 	u8 gcm_12[6];
128 	u8 gcm_2x[8];
129 };
130 
131 static const struct pef2256_gcm_config pef2256_gcm_configs[] = {
132 	[PEF2256_GCM_CONFIG_1544000] = {
133 		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x00, 0x15},
134 		.gcm_2x = {0x00, 0x15, 0x00, 0x08, 0x00, 0x3F, 0x9C, 0xDF},
135 	},
136 	[PEF2256_GCM_CONFIG_2048000] = {
137 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x00, 0x10},
138 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x2F, 0xDB, 0xDF},
139 	},
140 	[PEF2256_GCM_CONFIG_8192000] = {
141 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x03, 0x10},
142 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x0B, 0xDB, 0xDF},
143 	},
144 	[PEF2256_GCM_CONFIG_10000000] = {
145 		.gcm_12 = {0x90, 0x51, 0x81, 0x8F, 0x04, 0x10},
146 		.gcm_2x = {0x40, 0x1B, 0x3D, 0x0A, 0x00, 0x07, 0xC9, 0xDC},
147 	},
148 	[PEF2256_GCM_CONFIG_12352000] = {
149 		.gcm_12 = {0xF0, 0x51, 0x00, 0x80, 0x07, 0x15},
150 		.gcm_2x = {0x00, 0x19, 0x00, 0x08, 0x01, 0x0A, 0x98, 0xDA},
151 	},
152 	[PEF2256_GCM_CONFIG_16384000] = {
153 		.gcm_12 = {0x00, 0x58, 0xD2, 0xC2, 0x07, 0x10},
154 		.gcm_2x = {0x00, 0x18, 0xFB, 0x0B, 0x01, 0x0B, 0xDB, 0xDF},
155 	},
156 };
157 
158 static int pef2256_setup_gcm(struct pef2256 *pef2256)
159 {
160 	enum pef2256_gcm_config_item item;
161 	unsigned long mclk_rate;
162 	const u8 *gcm;
163 	int i, count;
164 
165 	mclk_rate = clk_get_rate(pef2256->mclk);
166 	switch (mclk_rate) {
167 	case 1544000:
168 		item = PEF2256_GCM_CONFIG_1544000;
169 		break;
170 	case 2048000:
171 		item = PEF2256_GCM_CONFIG_2048000;
172 		break;
173 	case 8192000:
174 		item = PEF2256_GCM_CONFIG_8192000;
175 		break;
176 	case 10000000:
177 		item = PEF2256_GCM_CONFIG_10000000;
178 		break;
179 	case 12352000:
180 		item = PEF2256_GCM_CONFIG_12352000;
181 		break;
182 	case 16384000:
183 		item = PEF2256_GCM_CONFIG_16384000;
184 		break;
185 	default:
186 		dev_err(pef2256->dev, "Unsupported v2.x MCLK rate %lu\n", mclk_rate);
187 		return -EINVAL;
188 	}
189 
190 	BUILD_BUG_ON(item >= ARRAY_SIZE(pef2256_gcm_configs));
191 
192 	if (pef2256->version == PEF2256_VERSION_1_2) {
193 		gcm = pef2256_gcm_configs[item].gcm_12;
194 		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_12);
195 	} else {
196 		gcm = pef2256_gcm_configs[item].gcm_2x;
197 		count = ARRAY_SIZE(pef2256_gcm_configs[item].gcm_2x);
198 	}
199 
200 	for (i = 0; i < count; i++)
201 		pef2256_write8(pef2256, PEF2256_GCM(i + 1), *(gcm + i));
202 
203 	return 0;
204 }
205 
206 static int pef2256_setup_e1_line(struct pef2256 *pef2256)
207 {
208 	u8 fmr1, fmr2;
209 
210 	/* RCLK output : DPLL clock, DCO-X enabled, DCO-X internal ref clock */
211 	pef2256_write8(pef2256, PEF2256_CMR1, 0x00);
212 
213 	/* SCLKR selected, SCLKX selected,
214 	 * receive synchro pulse sourced by SYPR,
215 	 * transmit synchro pulse sourced by SYPX,
216 	 * DCO-X center frequency enabled
217 	 */
218 	pef2256_write8(pef2256, PEF2256_CMR2, PEF2256_CMR2_DCOXC);
219 
220 	if (pef2256->is_subordinate) {
221 		/* select RCLK source = 2M,  disable switching from RCLK to SYNC */
222 		pef2256_clrsetbits8(pef2256, PEF2256_CMR1, PEF2256_CMR1_RS_MASK,
223 				    PEF2256_CMR1_RS_DCOR_2048 | PEF2256_CMR1_DCS);
224 	}
225 
226 	/* slave mode, local loop off, mode short-haul
227 	 * In v2.x, bit3 is a forced 1 bit in the datasheet -> Need to be set.
228 	 */
229 	if (pef2256->version == PEF2256_VERSION_1_2)
230 		pef2256_write8(pef2256, PEF2256_LIM0, 0x00);
231 	else
232 		pef2256_write8(pef2256, PEF2256_LIM0, PEF2256_2X_LIM0_BIT3);
233 
234 	/* "master" mode */
235 	if (!pef2256->is_subordinate)
236 		pef2256_setbits8(pef2256, PEF2256_LIM0, PEF2256_LIM0_MAS);
237 
238 	/* analog interface selected, remote loop off */
239 	pef2256_write8(pef2256, PEF2256_LIM1, 0x00);
240 
241 	/* receive input threshold = 0,21V */
242 	if (pef2256->version == PEF2256_VERSION_1_2)
243 		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_12_LIM1_RIL_MASK,
244 				    PEF2256_12_LIM1_RIL_210);
245 	else
246 		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_2X_LIM1_RIL_MASK,
247 				    PEF2256_2X_LIM1_RIL_210);
248 
249 	/* transmit pulse mask, default value from datasheet
250 	 * transmit line in normal operation
251 	 */
252 	if (pef2256->version == PEF2256_VERSION_1_2)
253 		pef2256_write8(pef2256, PEF2256_XPM0, 0x7B);
254 	else
255 		pef2256_write8(pef2256, PEF2256_XPM0, 0x9C);
256 	pef2256_write8(pef2256, PEF2256_XPM1, 0x03);
257 	pef2256_write8(pef2256, PEF2256_XPM2, 0x00);
258 
259 	/* HDB3 coding, no alarm simulation */
260 	pef2256_write8(pef2256, PEF2256_FMR0, PEF2256_FMR0_XC_HDB3 | PEF2256_FMR0_RC_HDB3);
261 
262 	/* E1, frame format, 2 Mbit/s system data rate, no AIS
263 	 * transmission to remote end or system interface, payload loop
264 	 * off, transmit remote alarm on
265 	 */
266 	fmr1 = 0x00;
267 	fmr2 = PEF2256_FMR2_AXRA;
268 	switch (pef2256->frame_type) {
269 	case PEF2256_FRAME_E1_DOUBLEFRAME:
270 		fmr2 |= PEF2256_FMR2_RFS_DOUBLEFRAME;
271 		break;
272 	case PEF2256_FRAME_E1_CRC4_MULTIFRAME:
273 		fmr1 |= PEF2256_FMR1_XFS;
274 		fmr2 |= PEF2256_FMR2_RFS_CRC4_MULTIFRAME;
275 		break;
276 	case PEF2256_FRAME_E1_AUTO_MULTIFRAME:
277 		fmr1 |= PEF2256_FMR1_XFS;
278 		fmr2 |= PEF2256_FMR2_RFS_AUTO_MULTIFRAME;
279 		break;
280 	default:
281 		dev_err(pef2256->dev, "Unsupported frame type %d\n", pef2256->frame_type);
282 		return -EINVAL;
283 	}
284 	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_XFS, fmr1);
285 	pef2256_write8(pef2256, PEF2256_FMR2, fmr2);
286 
287 	if (!pef2256->is_subordinate) {
288 		/* SEC input, active high */
289 		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_SEC_IN_HIGH);
290 	} else {
291 		/* FSC output, active high */
292 		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_FSC_OUT_HIGH);
293 	}
294 
295 	/* SCLKR, SCLKX, RCLK configured to inputs,
296 	 * XFMS active low, CLK1 and CLK2 pin configuration
297 	 */
298 	pef2256_write8(pef2256, PEF2256_PC5, 0x00);
299 	pef2256_write8(pef2256, PEF2256_PC6, 0x00);
300 
301 	/* port RCLK is output */
302 	pef2256_setbits8(pef2256, PEF2256_PC5, PEF2256_PC5_CRP);
303 
304 	return 0;
305 }
306 
307 static void pef2256_setup_e1_los(struct pef2256 *pef2256)
308 {
309 	/* detection of LOS alarm = 176 pulses (ie (10 + 1) * 16) */
310 	pef2256_write8(pef2256, PEF2256_PCD, 10);
311 	/* recovery of LOS alarm = 22 pulses (ie 21 + 1) */
312 	pef2256_write8(pef2256, PEF2256_PCR, 21);
313 	/* E1 default for the receive slicer threshold */
314 	pef2256_write8(pef2256, PEF2256_LIM2, PEF2256_LIM2_SLT_THR50);
315 	if (pef2256->is_subordinate) {
316 		/* Loop-timed */
317 		pef2256_setbits8(pef2256, PEF2256_LIM2, PEF2256_LIM2_ELT);
318 	}
319 }
320 
321 static int pef2256_setup_e1_system(struct pef2256 *pef2256)
322 {
323 	u8 sic1, fmr1;
324 
325 	/* 2.048 MHz system clocking rate, receive buffer 2 frames, transmit
326 	 * buffer bypass, data sampled and transmitted on the falling edge of
327 	 * SCLKR/X, automatic freeze signaling, data is active in the first
328 	 * channel phase
329 	 */
330 	pef2256_write8(pef2256, PEF2256_SIC1, 0x00);
331 	pef2256_write8(pef2256, PEF2256_SIC2, 0x00);
332 	pef2256_write8(pef2256, PEF2256_SIC3, 0x00);
333 
334 	if (pef2256->is_subordinate) {
335 		/* transmit buffer size = 2 frames, transparent mode */
336 		pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_XBS_MASK,
337 				    PEF2256_SIC1_XBS_2FRAMES);
338 	}
339 
340 	if (pef2256->version != PEF2256_VERSION_1_2) {
341 		/* during inactive channel phase switch RDO/RSIG into tri-state */
342 		pef2256_setbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RTRI);
343 	}
344 
345 	if (pef2256->is_tx_falling_edge) {
346 		/* falling edge sync pulse transmit, rising edge sync pulse receive */
347 		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESX, PEF2256_SIC3_RESR);
348 	} else {
349 		/* rising edge sync pulse transmit, falling edge sync pulse receive */
350 		pef2256_clrsetbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RESR, PEF2256_SIC3_RESX);
351 	}
352 
353 	/* transmit offset counter (XCO10..0) = 4 */
354 	pef2256_write8(pef2256, PEF2256_XC0, 0);
355 	pef2256_write8(pef2256, PEF2256_XC1, 4);
356 	/* receive offset counter (RCO10..0) = 4 */
357 	pef2256_write8(pef2256, PEF2256_RC0, 0);
358 	pef2256_write8(pef2256, PEF2256_RC1, 4);
359 
360 	/* system clock rate */
361 	switch (pef2256->sysclk_rate) {
362 	case 2048000:
363 		sic1 = PEF2256_SIC1_SSC_2048;
364 		break;
365 	case 4096000:
366 		sic1 = PEF2256_SIC1_SSC_4096;
367 		break;
368 	case 8192000:
369 		sic1 = PEF2256_SIC1_SSC_8192;
370 		break;
371 	case 16384000:
372 		sic1 = PEF2256_SIC1_SSC_16384;
373 		break;
374 	default:
375 		dev_err(pef2256->dev, "Unsupported sysclk rate %lu\n", pef2256->sysclk_rate);
376 		return -EINVAL;
377 	}
378 	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSC_MASK, sic1);
379 
380 	/* data clock rate */
381 	switch (pef2256->data_rate) {
382 	case 2048000:
383 		fmr1 = PEF2256_FMR1_SSD_2048;
384 		sic1 = PEF2256_SIC1_SSD_2048;
385 		break;
386 	case 4096000:
387 		fmr1 = PEF2256_FMR1_SSD_4096;
388 		sic1 = PEF2256_SIC1_SSD_4096;
389 		break;
390 	case 8192000:
391 		fmr1 = PEF2256_FMR1_SSD_8192;
392 		sic1 = PEF2256_SIC1_SSD_8192;
393 		break;
394 	case 16384000:
395 		fmr1 = PEF2256_FMR1_SSD_16384;
396 		sic1 = PEF2256_SIC1_SSD_16384;
397 		break;
398 	default:
399 		dev_err(pef2256->dev, "Unsupported data rate %u\n", pef2256->data_rate);
400 		return -EINVAL;
401 	}
402 	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_SSD_MASK, fmr1);
403 	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSD_MASK, sic1);
404 
405 	/* channel phase */
406 	pef2256_clrsetbits8(pef2256, PEF2256_SIC2, PEF2256_SIC2_SICS_MASK,
407 			    PEF2256_SIC2_SICS(pef2256->channel_phase));
408 
409 	return 0;
410 }
411 
412 static void pef2256_setup_e1_signaling(struct pef2256 *pef2256)
413 {
414 	/* All bits of the transmitted service word are cleared */
415 	pef2256_write8(pef2256, PEF2256_XSW, PEF2256_XSW_XY(0x1F));
416 
417 	/* CAS disabled and clear spare bit values */
418 	pef2256_write8(pef2256, PEF2256_XSP, 0x00);
419 
420 	if (pef2256->is_subordinate) {
421 		/* transparent mode */
422 		pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XTM);
423 	}
424 
425 	/* Si-Bit, Spare bit For International, FAS word */
426 	pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XSIS);
427 	pef2256_setbits8(pef2256, PEF2256_XSP, PEF2256_XSP_XSIF);
428 
429 	/* no transparent mode active */
430 	pef2256_write8(pef2256, PEF2256_TSWM, 0x00);
431 }
432 
433 static void pef2256_setup_e1_errors(struct pef2256 *pef2256)
434 {
435 	/* error counter latched every 1s */
436 	pef2256_setbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_ECM);
437 
438 	/* error counter mode COFA */
439 	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_ECMC);
440 
441 	/* errors in service words have no influence */
442 	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_SWD);
443 
444 	/* 4 consecutive incorrect FAS causes loss of sync */
445 	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_ASY4);
446 }
447 
448 static int pef2256_setup_e1(struct pef2256 *pef2256)
449 {
450 	int ret;
451 
452 	/* Setup, Master clocking mode (GCM8..1) */
453 	ret = pef2256_setup_gcm(pef2256);
454 	if (ret)
455 		return ret;
456 
457 	/* Select E1 mode */
458 	pef2256_write8(pef2256, PEF2256_FMR1, 0x00);
459 
460 	/* internal second timer, power on */
461 	pef2256_write8(pef2256, PEF2256_GCR, 0x00);
462 
463 	/* Setup line interface */
464 	ret = pef2256_setup_e1_line(pef2256);
465 	if (ret)
466 		return ret;
467 
468 	/* Setup Loss-of-signal detection and recovery */
469 	pef2256_setup_e1_los(pef2256);
470 
471 	/* Setup system interface */
472 	ret = pef2256_setup_e1_system(pef2256);
473 	if (ret)
474 		return ret;
475 
476 	/* Setup signaling */
477 	pef2256_setup_e1_signaling(pef2256);
478 
479 	/* Setup errors counters and condition */
480 	pef2256_setup_e1_errors(pef2256);
481 
482 	/* status changed interrupt at both up and down */
483 	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_SCI);
484 
485 	/* Clear any ISR2 pending interrupts and unmask needed interrupts */
486 	pef2256_read8(pef2256, PEF2256_ISR2);
487 	pef2256_clrbits8(pef2256, PEF2256_IMR2, PEF2256_INT2_LOS | PEF2256_INT2_AIS);
488 
489 	/* reset lines */
490 	pef2256_write8(pef2256, PEF2256_CMDR, PEF2256_CMDR_RRES | PEF2256_CMDR_XRES);
491 	return 0;
492 }
493 
494 static void pef2256_isr_default_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
495 {
496 	dev_warn_ratelimited(pef2256->dev, "ISR%u: 0x%02x not handled\n", nbr, isr);
497 }
498 
499 static bool pef2256_is_carrier_on(struct pef2256 *pef2256)
500 {
501 	u8 frs0;
502 
503 	frs0 = pef2256_read8(pef2256, PEF2256_FRS0);
504 	return !(frs0 & (PEF2256_FRS0_LOS | PEF2256_FRS0_AIS));
505 }
506 
507 static void pef2256_isr2_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
508 {
509 	bool carrier;
510 
511 	if (isr & (PEF2256_INT2_LOS | PEF2256_INT2_AIS)) {
512 		carrier = pef2256_is_carrier_on(pef2256);
513 		if (atomic_xchg(&pef2256->carrier, carrier) != carrier)
514 			framer_notify_status_change(pef2256->framer);
515 	}
516 }
517 
518 static irqreturn_t pef2256_irq_handler(int irq, void *priv)
519 {
520 	static void (*pef2256_isr_handler[])(struct pef2256 *, u8, u8) = {
521 		[0] = pef2256_isr_default_handler,
522 		[1] = pef2256_isr_default_handler,
523 		[2] = pef2256_isr2_handler,
524 		[3] = pef2256_isr_default_handler,
525 		[4] = pef2256_isr_default_handler,
526 		[5] = pef2256_isr_default_handler
527 	};
528 	struct pef2256 *pef2256 = (struct pef2256 *)priv;
529 	u8 gis;
530 	u8 isr;
531 	u8 n;
532 
533 	gis = pef2256_read8(pef2256, PEF2256_GIS);
534 
535 	for (n = 0; n < ARRAY_SIZE(pef2256_isr_handler); n++) {
536 		if (gis & PEF2256_GIS_ISR(n)) {
537 			isr = pef2256_read8(pef2256, PEF2256_ISR(n));
538 			pef2256_isr_handler[n](pef2256, n, isr);
539 		}
540 	}
541 
542 	return IRQ_HANDLED;
543 }
544 
545 static int pef2256_check_rates(struct pef2256 *pef2256, unsigned long sysclk_rate,
546 			       unsigned long data_rate)
547 {
548 	unsigned long rate;
549 
550 	switch (sysclk_rate) {
551 	case 2048000:
552 	case 4096000:
553 	case 8192000:
554 	case 16384000:
555 		break;
556 	default:
557 		dev_err(pef2256->dev, "Unsupported system clock rate %lu\n", sysclk_rate);
558 		return -EINVAL;
559 	}
560 
561 	for (rate = data_rate; rate <= data_rate * 4; rate *= 2) {
562 		if (rate == sysclk_rate)
563 			return 0;
564 	}
565 	dev_err(pef2256->dev, "Unsupported data rate %lu with system clock rate %lu\n",
566 		data_rate, sysclk_rate);
567 	return -EINVAL;
568 }
569 
570 static int pef2556_of_parse(struct pef2256 *pef2256, struct device_node *np)
571 {
572 	int ret;
573 
574 	pef2256->data_rate = 2048000;
575 	ret = of_property_read_u32(np, "lantiq,data-rate-bps", &pef2256->data_rate);
576 	if (ret && ret != -EINVAL) {
577 		dev_err(pef2256->dev, "%pOF: failed to read lantiq,data-rate-bps\n", np);
578 		return ret;
579 	}
580 
581 	ret =  pef2256_check_rates(pef2256, pef2256->sysclk_rate, pef2256->data_rate);
582 	if (ret)
583 		return ret;
584 
585 	pef2256->is_tx_falling_edge = of_property_read_bool(np, "lantiq,clock-falling-edge");
586 
587 	pef2256->channel_phase = 0;
588 	ret = of_property_read_u8(np, "lantiq,channel-phase", &pef2256->channel_phase);
589 	if (ret && ret != -EINVAL) {
590 		dev_err(pef2256->dev, "%pOF: failed to read lantiq,channel-phase\n",
591 			np);
592 		return ret;
593 	}
594 	if (pef2256->channel_phase >= pef2256->sysclk_rate / pef2256->data_rate) {
595 		dev_err(pef2256->dev, "%pOF: Invalid lantiq,channel-phase %u\n",
596 			np, pef2256->channel_phase);
597 		return -EINVAL;
598 	}
599 
600 	return 0;
601 }
602 
603 static const struct regmap_config pef2256_regmap_config = {
604 	.reg_bits = 32,
605 	.val_bits = 8,
606 	.max_register = 0xff,
607 };
608 
609 static const struct mfd_cell pef2256_devs[] = {
610 	{ .name = "lantiq-pef2256-pinctrl", },
611 };
612 
613 static int pef2256_add_audio_devices(struct pef2256 *pef2256)
614 {
615 	const char *compatible = "lantiq,pef2256-codec";
616 	struct mfd_cell *audio_devs;
617 	struct device_node *np;
618 	unsigned int count = 0;
619 	unsigned int i;
620 	int ret;
621 
622 	for_each_available_child_of_node(pef2256->dev->of_node, np) {
623 		if (of_device_is_compatible(np, compatible))
624 			count++;
625 	}
626 
627 	if (!count)
628 		return 0;
629 
630 	audio_devs = kcalloc(count, sizeof(*audio_devs), GFP_KERNEL);
631 	if (!audio_devs)
632 		return -ENOMEM;
633 
634 	for (i = 0; i < count; i++) {
635 		audio_devs[i].name = "framer-codec";
636 		audio_devs[i].of_compatible = compatible;
637 		audio_devs[i].id = i;
638 	}
639 
640 	ret = mfd_add_devices(pef2256->dev, 0, audio_devs, count, NULL, 0, NULL);
641 	kfree(audio_devs);
642 	return ret;
643 }
644 
645 static int pef2256_framer_get_status(struct framer *framer, struct framer_status *status)
646 {
647 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
648 
649 	status->link_is_on = !!atomic_read(&pef2256->carrier);
650 	return 0;
651 }
652 
653 static int pef2256_framer_set_config(struct framer *framer, const struct framer_config *config)
654 {
655 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
656 
657 	if (config->iface != FRAMER_IFACE_E1) {
658 		dev_err(pef2256->dev, "Only E1 line is currently supported\n");
659 		return -EOPNOTSUPP;
660 	}
661 
662 	switch (config->clock_type) {
663 	case FRAMER_CLOCK_EXT:
664 		pef2256->is_subordinate = true;
665 		break;
666 	case FRAMER_CLOCK_INT:
667 		pef2256->is_subordinate = false;
668 		break;
669 	default:
670 		return -EINVAL;
671 	}
672 
673 	/* Apply the new settings */
674 	return pef2256_setup_e1(pef2256);
675 }
676 
677 static int pef2256_framer_get_config(struct framer *framer, struct framer_config *config)
678 {
679 	struct pef2256 *pef2256 = framer_get_drvdata(framer);
680 
681 	config->iface = FRAMER_IFACE_E1;
682 	config->clock_type = pef2256->is_subordinate ? FRAMER_CLOCK_EXT : FRAMER_CLOCK_INT;
683 	config->line_clock_rate = 2048000;
684 	return 0;
685 }
686 
687 static const struct framer_ops pef2256_framer_ops = {
688 	.owner = THIS_MODULE,
689 	.get_status = pef2256_framer_get_status,
690 	.get_config = pef2256_framer_get_config,
691 	.set_config = pef2256_framer_set_config,
692 };
693 
694 static int pef2256_probe(struct platform_device *pdev)
695 {
696 	struct device_node *np = pdev->dev.of_node;
697 	unsigned long sclkr_rate, sclkx_rate;
698 	struct framer_provider *framer_provider;
699 	struct pef2256 *pef2256;
700 	const char *version_txt;
701 	void __iomem *iomem;
702 	int ret;
703 	int irq;
704 
705 	pef2256 = devm_kzalloc(&pdev->dev, sizeof(*pef2256), GFP_KERNEL);
706 	if (!pef2256)
707 		return -ENOMEM;
708 
709 	pef2256->dev = &pdev->dev;
710 	atomic_set(&pef2256->carrier, 0);
711 
712 	pef2256->is_subordinate = true;
713 	pef2256->frame_type = PEF2256_FRAME_E1_DOUBLEFRAME;
714 
715 	iomem = devm_platform_ioremap_resource(pdev, 0);
716 	if (IS_ERR(iomem))
717 		return PTR_ERR(iomem);
718 
719 	pef2256->regmap = devm_regmap_init_mmio(&pdev->dev, iomem,
720 						&pef2256_regmap_config);
721 	if (IS_ERR(pef2256->regmap)) {
722 		dev_err(&pdev->dev, "Failed to initialise Regmap (%ld)\n",
723 			PTR_ERR(pef2256->regmap));
724 		return PTR_ERR(pef2256->regmap);
725 	}
726 
727 	pef2256->mclk = devm_clk_get_enabled(&pdev->dev, "mclk");
728 	if (IS_ERR(pef2256->mclk))
729 		return PTR_ERR(pef2256->mclk);
730 
731 	pef2256->sclkr = devm_clk_get_enabled(&pdev->dev, "sclkr");
732 	if (IS_ERR(pef2256->sclkr))
733 		return PTR_ERR(pef2256->sclkr);
734 
735 	pef2256->sclkx = devm_clk_get_enabled(&pdev->dev, "sclkx");
736 	if (IS_ERR(pef2256->sclkx))
737 		return PTR_ERR(pef2256->sclkx);
738 
739 	/* Both SCLKR (receive) and SCLKX (transmit) must have the same rate,
740 	 * stored as sysclk_rate.
741 	 * The exact value will be checked at pef2256_check_rates()
742 	 */
743 	sclkr_rate = clk_get_rate(pef2256->sclkr);
744 	sclkx_rate = clk_get_rate(pef2256->sclkx);
745 	if (sclkr_rate != sclkx_rate) {
746 		dev_err(pef2256->dev, "clk rate mismatch. sclkr %lu Hz, sclkx %lu Hz\n",
747 			sclkr_rate, sclkx_rate);
748 		return -EINVAL;
749 	}
750 	pef2256->sysclk_rate = sclkr_rate;
751 
752 	/* Reset the component. The MCLK clock must be active during reset */
753 	pef2256->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
754 	if (IS_ERR(pef2256->reset_gpio))
755 		return PTR_ERR(pef2256->reset_gpio);
756 	if (pef2256->reset_gpio) {
757 		gpiod_set_value_cansleep(pef2256->reset_gpio, 1);
758 		usleep_range(10, 20);
759 		gpiod_set_value_cansleep(pef2256->reset_gpio, 0);
760 		usleep_range(10, 20);
761 	}
762 
763 	pef2256->version = pef2256_get_version(pef2256);
764 	switch (pef2256->version) {
765 	case PEF2256_VERSION_1_2:
766 		version_txt = "1.2";
767 		break;
768 	case PEF2256_VERSION_2_1:
769 		version_txt = "2.1";
770 		break;
771 	case PEF2256_VERSION_2_2:
772 		version_txt = "2.2";
773 		break;
774 	default:
775 		return -ENODEV;
776 	}
777 	dev_info(pef2256->dev, "Version %s detected\n", version_txt);
778 
779 	ret = pef2556_of_parse(pef2256, np);
780 	if (ret)
781 		return ret;
782 
783 	/* Create the framer. It can be used on interrupts */
784 	pef2256->framer = devm_framer_create(pef2256->dev, NULL, &pef2256_framer_ops);
785 	if (IS_ERR(pef2256->framer))
786 		return PTR_ERR(pef2256->framer);
787 
788 	framer_set_drvdata(pef2256->framer, pef2256);
789 
790 	/* Disable interrupts */
791 	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
792 	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
793 	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
794 	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
795 	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
796 	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
797 
798 	/* Clear any pending interrupts */
799 	pef2256_read8(pef2256, PEF2256_ISR0);
800 	pef2256_read8(pef2256, PEF2256_ISR1);
801 	pef2256_read8(pef2256, PEF2256_ISR2);
802 	pef2256_read8(pef2256, PEF2256_ISR3);
803 	pef2256_read8(pef2256, PEF2256_ISR4);
804 	pef2256_read8(pef2256, PEF2256_ISR5);
805 
806 	irq = platform_get_irq(pdev, 0);
807 	if (irq < 0)
808 		return irq;
809 	ret = devm_request_irq(pef2256->dev, irq, pef2256_irq_handler, 0, "pef2256", pef2256);
810 	if (ret < 0)
811 		return ret;
812 
813 	platform_set_drvdata(pdev, pef2256);
814 
815 	ret = mfd_add_devices(pef2256->dev, 0, pef2256_devs,
816 			      ARRAY_SIZE(pef2256_devs), NULL, 0, NULL);
817 	if (ret) {
818 		dev_err(pef2256->dev, "add devices failed (%d)\n", ret);
819 		return ret;
820 	}
821 
822 	ret = pef2256_setup_e1(pef2256);
823 	if (ret)
824 		return ret;
825 
826 	framer_provider = devm_framer_provider_of_register(pef2256->dev,
827 							   framer_provider_simple_of_xlate);
828 	if (IS_ERR(framer_provider))
829 		return PTR_ERR(framer_provider);
830 
831 	/* Add audio devices */
832 	ret = pef2256_add_audio_devices(pef2256);
833 	if (ret < 0) {
834 		dev_err(pef2256->dev, "add audio devices failed (%d)\n", ret);
835 		return ret;
836 	}
837 
838 	return 0;
839 }
840 
841 static void pef2256_remove(struct platform_device *pdev)
842 {
843 	struct pef2256 *pef2256 = platform_get_drvdata(pdev);
844 
845 	/* Disable interrupts */
846 	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
847 	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
848 	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
849 	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
850 	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
851 	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
852 }
853 
854 static const struct of_device_id pef2256_id_table[] = {
855 	{ .compatible = "lantiq,pef2256" },
856 	{} /* sentinel */
857 };
858 MODULE_DEVICE_TABLE(of, pef2256_id_table);
859 
860 static struct platform_driver pef2256_driver = {
861 	.driver = {
862 		.name = "lantiq-pef2256",
863 		.of_match_table = pef2256_id_table,
864 	},
865 	.probe = pef2256_probe,
866 	.remove = pef2256_remove,
867 };
868 module_platform_driver(pef2256_driver);
869 
870 struct regmap *pef2256_get_regmap(struct pef2256 *pef2256)
871 {
872 	return pef2256->regmap;
873 }
874 EXPORT_SYMBOL_GPL(pef2256_get_regmap);
875 
876 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
877 MODULE_DESCRIPTION("PEF2256 driver");
878 MODULE_LICENSE("GPL");
879