xref: /openbmc/linux/drivers/clk/clk-si5341.c (revision 165f2d28)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for Silicon Labs Si5341/Si5340 Clock generator
4  * Copyright (C) 2019 Topic Embedded Products
5  * Author: Mike Looijmans <mike.looijmans@topic.nl>
6  */
7 
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/delay.h>
11 #include <linux/gcd.h>
12 #include <linux/math64.h>
13 #include <linux/i2c.h>
14 #include <linux/module.h>
15 #include <linux/regmap.h>
16 #include <linux/slab.h>
17 #include <asm/unaligned.h>
18 
19 #define SI5341_NUM_INPUTS 4
20 
21 #define SI5341_MAX_NUM_OUTPUTS 10
22 #define SI5340_MAX_NUM_OUTPUTS 4
23 
24 #define SI5341_NUM_SYNTH 5
25 #define SI5340_NUM_SYNTH 4
26 
27 /* Range of the synthesizer fractional divider */
28 #define SI5341_SYNTH_N_MIN	10
29 #define SI5341_SYNTH_N_MAX	4095
30 
31 /* The chip can get its input clock from 3 input pins or an XTAL */
32 
33 /* There is one PLL running at 13500–14256 MHz */
34 #define SI5341_PLL_VCO_MIN 13500000000ull
35 #define SI5341_PLL_VCO_MAX 14256000000ull
36 
37 /* The 5 frequency synthesizers obtain their input from the PLL */
38 struct clk_si5341_synth {
39 	struct clk_hw hw;
40 	struct clk_si5341 *data;
41 	u8 index;
42 };
43 #define to_clk_si5341_synth(_hw) \
44 	container_of(_hw, struct clk_si5341_synth, hw)
45 
46 /* The output stages can be connected to any synth (full mux) */
47 struct clk_si5341_output {
48 	struct clk_hw hw;
49 	struct clk_si5341 *data;
50 	u8 index;
51 };
52 #define to_clk_si5341_output(_hw) \
53 	container_of(_hw, struct clk_si5341_output, hw)
54 
55 struct clk_si5341 {
56 	struct clk_hw hw;
57 	struct regmap *regmap;
58 	struct i2c_client *i2c_client;
59 	struct clk_si5341_synth synth[SI5341_NUM_SYNTH];
60 	struct clk_si5341_output clk[SI5341_MAX_NUM_OUTPUTS];
61 	struct clk *input_clk[SI5341_NUM_INPUTS];
62 	const char *input_clk_name[SI5341_NUM_INPUTS];
63 	const u16 *reg_output_offset;
64 	const u16 *reg_rdiv_offset;
65 	u64 freq_vco; /* 13500–14256 MHz */
66 	u8 num_outputs;
67 	u8 num_synth;
68 };
69 #define to_clk_si5341(_hw)	container_of(_hw, struct clk_si5341, hw)
70 
71 struct clk_si5341_output_config {
72 	u8 out_format_drv_bits;
73 	u8 out_cm_ampl_bits;
74 	bool synth_master;
75 	bool always_on;
76 };
77 
78 #define SI5341_PAGE		0x0001
79 #define SI5341_PN_BASE		0x0002
80 #define SI5341_DEVICE_REV	0x0005
81 #define SI5341_STATUS		0x000C
82 #define SI5341_SOFT_RST		0x001C
83 #define SI5341_IN_SEL		0x0021
84 #define SI5341_XAXB_CFG		0x090E
85 #define SI5341_IN_EN		0x0949
86 #define SI5341_INX_TO_PFD_EN	0x094A
87 
88 /* Input selection */
89 #define SI5341_IN_SEL_MASK	0x06
90 #define SI5341_IN_SEL_SHIFT	1
91 #define SI5341_IN_SEL_REGCTRL	0x01
92 #define SI5341_INX_TO_PFD_SHIFT	4
93 
94 /* XTAL config bits */
95 #define SI5341_XAXB_CFG_EXTCLK_EN	BIT(0)
96 #define SI5341_XAXB_CFG_PDNB		BIT(1)
97 
98 /* Input dividers (48-bit) */
99 #define SI5341_IN_PDIV(x)	(0x0208 + ((x) * 10))
100 #define SI5341_IN_PSET(x)	(0x020E + ((x) * 10))
101 #define SI5341_PX_UPD		0x0230
102 
103 /* PLL configuration */
104 #define SI5341_PLL_M_NUM	0x0235
105 #define SI5341_PLL_M_DEN	0x023B
106 
107 /* Output configuration */
108 #define SI5341_OUT_CONFIG(output)	\
109 			((output)->data->reg_output_offset[(output)->index])
110 #define SI5341_OUT_FORMAT(output)	(SI5341_OUT_CONFIG(output) + 1)
111 #define SI5341_OUT_CM(output)		(SI5341_OUT_CONFIG(output) + 2)
112 #define SI5341_OUT_MUX_SEL(output)	(SI5341_OUT_CONFIG(output) + 3)
113 #define SI5341_OUT_R_REG(output)	\
114 			((output)->data->reg_rdiv_offset[(output)->index])
115 
116 /* Synthesize N divider */
117 #define SI5341_SYNTH_N_NUM(x)	(0x0302 + ((x) * 11))
118 #define SI5341_SYNTH_N_DEN(x)	(0x0308 + ((x) * 11))
119 #define SI5341_SYNTH_N_UPD(x)	(0x030C + ((x) * 11))
120 
121 /* Synthesizer output enable, phase bypass, power mode */
122 #define SI5341_SYNTH_N_CLK_TO_OUTX_EN	0x0A03
123 #define SI5341_SYNTH_N_PIBYP		0x0A04
124 #define SI5341_SYNTH_N_PDNB		0x0A05
125 #define SI5341_SYNTH_N_CLK_DIS		0x0B4A
126 
127 #define SI5341_REGISTER_MAX	0xBFF
128 
129 /* SI5341_OUT_CONFIG bits */
130 #define SI5341_OUT_CFG_PDN		BIT(0)
131 #define SI5341_OUT_CFG_OE		BIT(1)
132 #define SI5341_OUT_CFG_RDIV_FORCE2	BIT(2)
133 
134 /* Static configuration (to be moved to firmware) */
135 struct si5341_reg_default {
136 	u16 address;
137 	u8 value;
138 };
139 
140 static const char * const si5341_input_clock_names[] = {
141 	"in0", "in1", "in2", "xtal"
142 };
143 
144 /* Output configuration registers 0..9 are not quite logically organized */
145 static const u16 si5341_reg_output_offset[] = {
146 	0x0108,
147 	0x010D,
148 	0x0112,
149 	0x0117,
150 	0x011C,
151 	0x0121,
152 	0x0126,
153 	0x012B,
154 	0x0130,
155 	0x013A,
156 };
157 
158 static const u16 si5340_reg_output_offset[] = {
159 	0x0112,
160 	0x0117,
161 	0x0126,
162 	0x012B,
163 };
164 
165 /* The location of the R divider registers */
166 static const u16 si5341_reg_rdiv_offset[] = {
167 	0x024A,
168 	0x024D,
169 	0x0250,
170 	0x0253,
171 	0x0256,
172 	0x0259,
173 	0x025C,
174 	0x025F,
175 	0x0262,
176 	0x0268,
177 };
178 static const u16 si5340_reg_rdiv_offset[] = {
179 	0x0250,
180 	0x0253,
181 	0x025C,
182 	0x025F,
183 };
184 
185 /*
186  * Programming sequence from ClockBuilder, settings to initialize the system
187  * using only the XTAL input, without pre-divider.
188  * This also contains settings that aren't mentioned anywhere in the datasheet.
189  * The "known" settings like synth and output configuration are done later.
190  */
191 static const struct si5341_reg_default si5341_reg_defaults[] = {
192 	{ 0x0017, 0x3A }, /* INT mask (disable interrupts) */
193 	{ 0x0018, 0xFF }, /* INT mask */
194 	{ 0x0021, 0x0F }, /* Select XTAL as input */
195 	{ 0x0022, 0x00 }, /* Not in datasheet */
196 	{ 0x002B, 0x02 }, /* SPI config */
197 	{ 0x002C, 0x20 }, /* LOS enable for XTAL */
198 	{ 0x002D, 0x00 }, /* LOS timing */
199 	{ 0x002E, 0x00 },
200 	{ 0x002F, 0x00 },
201 	{ 0x0030, 0x00 },
202 	{ 0x0031, 0x00 },
203 	{ 0x0032, 0x00 },
204 	{ 0x0033, 0x00 },
205 	{ 0x0034, 0x00 },
206 	{ 0x0035, 0x00 },
207 	{ 0x0036, 0x00 },
208 	{ 0x0037, 0x00 },
209 	{ 0x0038, 0x00 }, /* LOS setting (thresholds) */
210 	{ 0x0039, 0x00 },
211 	{ 0x003A, 0x00 },
212 	{ 0x003B, 0x00 },
213 	{ 0x003C, 0x00 },
214 	{ 0x003D, 0x00 }, /* LOS setting (thresholds) end */
215 	{ 0x0041, 0x00 }, /* LOS0_DIV_SEL */
216 	{ 0x0042, 0x00 }, /* LOS1_DIV_SEL */
217 	{ 0x0043, 0x00 }, /* LOS2_DIV_SEL */
218 	{ 0x0044, 0x00 }, /* LOS3_DIV_SEL */
219 	{ 0x009E, 0x00 }, /* Not in datasheet */
220 	{ 0x0102, 0x01 }, /* Enable outputs */
221 	{ 0x013F, 0x00 }, /* Not in datasheet */
222 	{ 0x0140, 0x00 }, /* Not in datasheet */
223 	{ 0x0141, 0x40 }, /* OUT LOS */
224 	{ 0x0202, 0x00 }, /* XAXB_FREQ_OFFSET (=0)*/
225 	{ 0x0203, 0x00 },
226 	{ 0x0204, 0x00 },
227 	{ 0x0205, 0x00 },
228 	{ 0x0206, 0x00 }, /* PXAXB (2^x) */
229 	{ 0x0208, 0x00 }, /* Px divider setting (usually 0) */
230 	{ 0x0209, 0x00 },
231 	{ 0x020A, 0x00 },
232 	{ 0x020B, 0x00 },
233 	{ 0x020C, 0x00 },
234 	{ 0x020D, 0x00 },
235 	{ 0x020E, 0x00 },
236 	{ 0x020F, 0x00 },
237 	{ 0x0210, 0x00 },
238 	{ 0x0211, 0x00 },
239 	{ 0x0212, 0x00 },
240 	{ 0x0213, 0x00 },
241 	{ 0x0214, 0x00 },
242 	{ 0x0215, 0x00 },
243 	{ 0x0216, 0x00 },
244 	{ 0x0217, 0x00 },
245 	{ 0x0218, 0x00 },
246 	{ 0x0219, 0x00 },
247 	{ 0x021A, 0x00 },
248 	{ 0x021B, 0x00 },
249 	{ 0x021C, 0x00 },
250 	{ 0x021D, 0x00 },
251 	{ 0x021E, 0x00 },
252 	{ 0x021F, 0x00 },
253 	{ 0x0220, 0x00 },
254 	{ 0x0221, 0x00 },
255 	{ 0x0222, 0x00 },
256 	{ 0x0223, 0x00 },
257 	{ 0x0224, 0x00 },
258 	{ 0x0225, 0x00 },
259 	{ 0x0226, 0x00 },
260 	{ 0x0227, 0x00 },
261 	{ 0x0228, 0x00 },
262 	{ 0x0229, 0x00 },
263 	{ 0x022A, 0x00 },
264 	{ 0x022B, 0x00 },
265 	{ 0x022C, 0x00 },
266 	{ 0x022D, 0x00 },
267 	{ 0x022E, 0x00 },
268 	{ 0x022F, 0x00 }, /* Px divider setting (usually 0) end */
269 	{ 0x026B, 0x00 }, /* DESIGN_ID (ASCII string) */
270 	{ 0x026C, 0x00 },
271 	{ 0x026D, 0x00 },
272 	{ 0x026E, 0x00 },
273 	{ 0x026F, 0x00 },
274 	{ 0x0270, 0x00 },
275 	{ 0x0271, 0x00 },
276 	{ 0x0272, 0x00 }, /* DESIGN_ID (ASCII string) end */
277 	{ 0x0339, 0x1F }, /* N_FSTEP_MSK */
278 	{ 0x033B, 0x00 }, /* Nx_FSTEPW (Frequency step) */
279 	{ 0x033C, 0x00 },
280 	{ 0x033D, 0x00 },
281 	{ 0x033E, 0x00 },
282 	{ 0x033F, 0x00 },
283 	{ 0x0340, 0x00 },
284 	{ 0x0341, 0x00 },
285 	{ 0x0342, 0x00 },
286 	{ 0x0343, 0x00 },
287 	{ 0x0344, 0x00 },
288 	{ 0x0345, 0x00 },
289 	{ 0x0346, 0x00 },
290 	{ 0x0347, 0x00 },
291 	{ 0x0348, 0x00 },
292 	{ 0x0349, 0x00 },
293 	{ 0x034A, 0x00 },
294 	{ 0x034B, 0x00 },
295 	{ 0x034C, 0x00 },
296 	{ 0x034D, 0x00 },
297 	{ 0x034E, 0x00 },
298 	{ 0x034F, 0x00 },
299 	{ 0x0350, 0x00 },
300 	{ 0x0351, 0x00 },
301 	{ 0x0352, 0x00 },
302 	{ 0x0353, 0x00 },
303 	{ 0x0354, 0x00 },
304 	{ 0x0355, 0x00 },
305 	{ 0x0356, 0x00 },
306 	{ 0x0357, 0x00 },
307 	{ 0x0358, 0x00 }, /* Nx_FSTEPW (Frequency step) end */
308 	{ 0x0359, 0x00 }, /* Nx_DELAY */
309 	{ 0x035A, 0x00 },
310 	{ 0x035B, 0x00 },
311 	{ 0x035C, 0x00 },
312 	{ 0x035D, 0x00 },
313 	{ 0x035E, 0x00 },
314 	{ 0x035F, 0x00 },
315 	{ 0x0360, 0x00 },
316 	{ 0x0361, 0x00 },
317 	{ 0x0362, 0x00 }, /* Nx_DELAY end */
318 	{ 0x0802, 0x00 }, /* Not in datasheet */
319 	{ 0x0803, 0x00 }, /* Not in datasheet */
320 	{ 0x0804, 0x00 }, /* Not in datasheet */
321 	{ 0x090E, 0x02 }, /* XAXB_EXTCLK_EN=0 XAXB_PDNB=1 (use XTAL) */
322 	{ 0x091C, 0x04 }, /* ZDM_EN=4 (Normal mode) */
323 	{ 0x0943, 0x00 }, /* IO_VDD_SEL=0 (0=1v8, use 1=3v3) */
324 	{ 0x0949, 0x00 }, /* IN_EN (disable input clocks) */
325 	{ 0x094A, 0x00 }, /* INx_TO_PFD_EN (disabled) */
326 	{ 0x0A02, 0x00 }, /* Not in datasheet */
327 	{ 0x0B44, 0x0F }, /* PDIV_ENB (datasheet does not mention what it is) */
328 };
329 
330 /* Read and interpret a 44-bit followed by a 32-bit value in the regmap */
331 static int si5341_decode_44_32(struct regmap *regmap, unsigned int reg,
332 	u64 *val1, u32 *val2)
333 {
334 	int err;
335 	u8 r[10];
336 
337 	err = regmap_bulk_read(regmap, reg, r, 10);
338 	if (err < 0)
339 		return err;
340 
341 	*val1 = ((u64)((r[5] & 0x0f) << 8 | r[4]) << 32) |
342 		 (get_unaligned_le32(r));
343 	*val2 = get_unaligned_le32(&r[6]);
344 
345 	return 0;
346 }
347 
348 static int si5341_encode_44_32(struct regmap *regmap, unsigned int reg,
349 	u64 n_num, u32 n_den)
350 {
351 	u8 r[10];
352 
353 	/* Shift left as far as possible without overflowing */
354 	while (!(n_num & BIT_ULL(43)) && !(n_den & BIT(31))) {
355 		n_num <<= 1;
356 		n_den <<= 1;
357 	}
358 
359 	/* 44 bits (6 bytes) numerator */
360 	put_unaligned_le32(n_num, r);
361 	r[4] = (n_num >> 32) & 0xff;
362 	r[5] = (n_num >> 40) & 0x0f;
363 	/* 32 bits denominator */
364 	put_unaligned_le32(n_den, &r[6]);
365 
366 	/* Program the fraction */
367 	return regmap_bulk_write(regmap, reg, r, sizeof(r));
368 }
369 
370 /* VCO, we assume it runs at a constant frequency */
371 static unsigned long si5341_clk_recalc_rate(struct clk_hw *hw,
372 		unsigned long parent_rate)
373 {
374 	struct clk_si5341 *data = to_clk_si5341(hw);
375 	int err;
376 	u64 res;
377 	u64 m_num;
378 	u32 m_den;
379 	unsigned int shift;
380 
381 	/* Assume that PDIV is not being used, just read the PLL setting */
382 	err = si5341_decode_44_32(data->regmap, SI5341_PLL_M_NUM,
383 				&m_num, &m_den);
384 	if (err < 0)
385 		return 0;
386 
387 	if (!m_num || !m_den)
388 		return 0;
389 
390 	/*
391 	 * Though m_num is 64-bit, only the upper bits are actually used. While
392 	 * calculating m_num and m_den, they are shifted as far as possible to
393 	 * the left. To avoid 96-bit division here, we just shift them back so
394 	 * we can do with just 64 bits.
395 	 */
396 	shift = 0;
397 	res = m_num;
398 	while (res & 0xffff00000000ULL) {
399 		++shift;
400 		res >>= 1;
401 	}
402 	res *= parent_rate;
403 	do_div(res, (m_den >> shift));
404 
405 	/* We cannot return the actual frequency in 32 bit, store it locally */
406 	data->freq_vco = res;
407 
408 	/* Report kHz since the value is out of range */
409 	do_div(res, 1000);
410 
411 	return (unsigned long)res;
412 }
413 
414 static int si5341_clk_get_selected_input(struct clk_si5341 *data)
415 {
416 	int err;
417 	u32 val;
418 
419 	err = regmap_read(data->regmap, SI5341_IN_SEL, &val);
420 	if (err < 0)
421 		return err;
422 
423 	return (val & SI5341_IN_SEL_MASK) >> SI5341_IN_SEL_SHIFT;
424 }
425 
426 static u8 si5341_clk_get_parent(struct clk_hw *hw)
427 {
428 	struct clk_si5341 *data = to_clk_si5341(hw);
429 	int res = si5341_clk_get_selected_input(data);
430 
431 	if (res < 0)
432 		return 0; /* Apparently we cannot report errors */
433 
434 	return res;
435 }
436 
437 static int si5341_clk_reparent(struct clk_si5341 *data, u8 index)
438 {
439 	int err;
440 	u8 val;
441 
442 	val = (index << SI5341_IN_SEL_SHIFT) & SI5341_IN_SEL_MASK;
443 	/* Enable register-based input selection */
444 	val |= SI5341_IN_SEL_REGCTRL;
445 
446 	err = regmap_update_bits(data->regmap,
447 		SI5341_IN_SEL, SI5341_IN_SEL_REGCTRL | SI5341_IN_SEL_MASK, val);
448 	if (err < 0)
449 		return err;
450 
451 	if (index < 3) {
452 		/* Enable input buffer for selected input */
453 		err = regmap_update_bits(data->regmap,
454 				SI5341_IN_EN, 0x07, BIT(index));
455 		if (err < 0)
456 			return err;
457 
458 		/* Enables the input to phase detector */
459 		err = regmap_update_bits(data->regmap, SI5341_INX_TO_PFD_EN,
460 				0x7 << SI5341_INX_TO_PFD_SHIFT,
461 				BIT(index + SI5341_INX_TO_PFD_SHIFT));
462 		if (err < 0)
463 			return err;
464 
465 		/* Power down XTAL oscillator and buffer */
466 		err = regmap_update_bits(data->regmap, SI5341_XAXB_CFG,
467 				SI5341_XAXB_CFG_PDNB, 0);
468 		if (err < 0)
469 			return err;
470 
471 		/*
472 		 * Set the P divider to "1". There's no explanation in the
473 		 * datasheet of these registers, but the clockbuilder software
474 		 * programs a "1" when the input is being used.
475 		 */
476 		err = regmap_write(data->regmap, SI5341_IN_PDIV(index), 1);
477 		if (err < 0)
478 			return err;
479 
480 		err = regmap_write(data->regmap, SI5341_IN_PSET(index), 1);
481 		if (err < 0)
482 			return err;
483 
484 		/* Set update PDIV bit */
485 		err = regmap_write(data->regmap, SI5341_PX_UPD, BIT(index));
486 		if (err < 0)
487 			return err;
488 	} else {
489 		/* Disable all input buffers */
490 		err = regmap_update_bits(data->regmap, SI5341_IN_EN, 0x07, 0);
491 		if (err < 0)
492 			return err;
493 
494 		/* Disable input to phase detector */
495 		err = regmap_update_bits(data->regmap, SI5341_INX_TO_PFD_EN,
496 				0x7 << SI5341_INX_TO_PFD_SHIFT, 0);
497 		if (err < 0)
498 			return err;
499 
500 		/* Power up XTAL oscillator and buffer */
501 		err = regmap_update_bits(data->regmap, SI5341_XAXB_CFG,
502 				SI5341_XAXB_CFG_PDNB, SI5341_XAXB_CFG_PDNB);
503 		if (err < 0)
504 			return err;
505 	}
506 
507 	return 0;
508 }
509 
510 static int si5341_clk_set_parent(struct clk_hw *hw, u8 index)
511 {
512 	struct clk_si5341 *data = to_clk_si5341(hw);
513 
514 	return si5341_clk_reparent(data, index);
515 }
516 
517 static const struct clk_ops si5341_clk_ops = {
518 	.set_parent = si5341_clk_set_parent,
519 	.get_parent = si5341_clk_get_parent,
520 	.recalc_rate = si5341_clk_recalc_rate,
521 };
522 
523 /* Synthesizers, there are 5 synthesizers that connect to any of the outputs */
524 
525 /* The synthesizer is on if all power and enable bits are set */
526 static int si5341_synth_clk_is_on(struct clk_hw *hw)
527 {
528 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
529 	int err;
530 	u32 val;
531 	u8 index = synth->index;
532 
533 	err = regmap_read(synth->data->regmap,
534 			SI5341_SYNTH_N_CLK_TO_OUTX_EN, &val);
535 	if (err < 0)
536 		return 0;
537 
538 	if (!(val & BIT(index)))
539 		return 0;
540 
541 	err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_PDNB, &val);
542 	if (err < 0)
543 		return 0;
544 
545 	if (!(val & BIT(index)))
546 		return 0;
547 
548 	/* This bit must be 0 for the synthesizer to receive clock input */
549 	err = regmap_read(synth->data->regmap, SI5341_SYNTH_N_CLK_DIS, &val);
550 	if (err < 0)
551 		return 0;
552 
553 	return !(val & BIT(index));
554 }
555 
556 static void si5341_synth_clk_unprepare(struct clk_hw *hw)
557 {
558 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
559 	u8 index = synth->index; /* In range 0..5 */
560 	u8 mask = BIT(index);
561 
562 	/* Disable output */
563 	regmap_update_bits(synth->data->regmap,
564 		SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, 0);
565 	/* Power down */
566 	regmap_update_bits(synth->data->regmap,
567 		SI5341_SYNTH_N_PDNB, mask, 0);
568 	/* Disable clock input to synth (set to 1 to disable) */
569 	regmap_update_bits(synth->data->regmap,
570 		SI5341_SYNTH_N_CLK_DIS, mask, mask);
571 }
572 
573 static int si5341_synth_clk_prepare(struct clk_hw *hw)
574 {
575 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
576 	int err;
577 	u8 index = synth->index;
578 	u8 mask = BIT(index);
579 
580 	/* Power up */
581 	err = regmap_update_bits(synth->data->regmap,
582 		SI5341_SYNTH_N_PDNB, mask, mask);
583 	if (err < 0)
584 		return err;
585 
586 	/* Enable clock input to synth (set bit to 0 to enable) */
587 	err = regmap_update_bits(synth->data->regmap,
588 		SI5341_SYNTH_N_CLK_DIS, mask, 0);
589 	if (err < 0)
590 		return err;
591 
592 	/* Enable output */
593 	return regmap_update_bits(synth->data->regmap,
594 		SI5341_SYNTH_N_CLK_TO_OUTX_EN, mask, mask);
595 }
596 
597 /* Synth clock frequency: Fvco * n_den / n_den, with Fvco in 13500-14256 MHz */
598 static unsigned long si5341_synth_clk_recalc_rate(struct clk_hw *hw,
599 		unsigned long parent_rate)
600 {
601 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
602 	u64 f;
603 	u64 n_num;
604 	u32 n_den;
605 	int err;
606 
607 	err = si5341_decode_44_32(synth->data->regmap,
608 			SI5341_SYNTH_N_NUM(synth->index), &n_num, &n_den);
609 	if (err < 0)
610 		return err;
611 
612 	/*
613 	 * n_num and n_den are shifted left as much as possible, so to prevent
614 	 * overflow in 64-bit math, we shift n_den 4 bits to the right
615 	 */
616 	f = synth->data->freq_vco;
617 	f *= n_den >> 4;
618 
619 	/* Now we need to to 64-bit division: f/n_num */
620 	/* And compensate for the 4 bits we dropped */
621 	f = div64_u64(f, (n_num >> 4));
622 
623 	return f;
624 }
625 
626 static long si5341_synth_clk_round_rate(struct clk_hw *hw, unsigned long rate,
627 		unsigned long *parent_rate)
628 {
629 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
630 	u64 f;
631 
632 	/* The synthesizer accuracy is such that anything in range will work */
633 	f = synth->data->freq_vco;
634 	do_div(f, SI5341_SYNTH_N_MAX);
635 	if (rate < f)
636 		return f;
637 
638 	f = synth->data->freq_vco;
639 	do_div(f, SI5341_SYNTH_N_MIN);
640 	if (rate > f)
641 		return f;
642 
643 	return rate;
644 }
645 
646 static int si5341_synth_program(struct clk_si5341_synth *synth,
647 	u64 n_num, u32 n_den, bool is_integer)
648 {
649 	int err;
650 	u8 index = synth->index;
651 
652 	err = si5341_encode_44_32(synth->data->regmap,
653 			SI5341_SYNTH_N_NUM(index), n_num, n_den);
654 
655 	err = regmap_update_bits(synth->data->regmap,
656 		SI5341_SYNTH_N_PIBYP, BIT(index), is_integer ? BIT(index) : 0);
657 	if (err < 0)
658 		return err;
659 
660 	return regmap_write(synth->data->regmap,
661 		SI5341_SYNTH_N_UPD(index), 0x01);
662 }
663 
664 
665 static int si5341_synth_clk_set_rate(struct clk_hw *hw, unsigned long rate,
666 		unsigned long parent_rate)
667 {
668 	struct clk_si5341_synth *synth = to_clk_si5341_synth(hw);
669 	u64 n_num;
670 	u32 n_den;
671 	u32 r;
672 	u32 g;
673 	bool is_integer;
674 
675 	n_num = synth->data->freq_vco;
676 
677 	/* see if there's an integer solution */
678 	r = do_div(n_num, rate);
679 	is_integer = (r == 0);
680 	if (is_integer) {
681 		/* Integer divider equal to n_num */
682 		n_den = 1;
683 	} else {
684 		/* Calculate a fractional solution */
685 		g = gcd(r, rate);
686 		n_den = rate / g;
687 		n_num *= n_den;
688 		n_num += r / g;
689 	}
690 
691 	dev_dbg(&synth->data->i2c_client->dev,
692 			"%s(%u): n=0x%llx d=0x%x %s\n", __func__,
693 				synth->index, n_num, n_den,
694 				is_integer ? "int" : "frac");
695 
696 	return si5341_synth_program(synth, n_num, n_den, is_integer);
697 }
698 
699 static const struct clk_ops si5341_synth_clk_ops = {
700 	.is_prepared = si5341_synth_clk_is_on,
701 	.prepare = si5341_synth_clk_prepare,
702 	.unprepare = si5341_synth_clk_unprepare,
703 	.recalc_rate = si5341_synth_clk_recalc_rate,
704 	.round_rate = si5341_synth_clk_round_rate,
705 	.set_rate = si5341_synth_clk_set_rate,
706 };
707 
708 static int si5341_output_clk_is_on(struct clk_hw *hw)
709 {
710 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
711 	int err;
712 	u32 val;
713 
714 	err = regmap_read(output->data->regmap,
715 			SI5341_OUT_CONFIG(output), &val);
716 	if (err < 0)
717 		return err;
718 
719 	/* Bit 0=PDN, 1=OE so only a value of 0x2 enables the output */
720 	return (val & 0x03) == SI5341_OUT_CFG_OE;
721 }
722 
723 /* Disables and then powers down the output */
724 static void si5341_output_clk_unprepare(struct clk_hw *hw)
725 {
726 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
727 
728 	regmap_update_bits(output->data->regmap,
729 			SI5341_OUT_CONFIG(output),
730 			SI5341_OUT_CFG_OE, 0);
731 	regmap_update_bits(output->data->regmap,
732 			SI5341_OUT_CONFIG(output),
733 			SI5341_OUT_CFG_PDN, SI5341_OUT_CFG_PDN);
734 }
735 
736 /* Powers up and then enables the output */
737 static int si5341_output_clk_prepare(struct clk_hw *hw)
738 {
739 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
740 	int err;
741 
742 	err = regmap_update_bits(output->data->regmap,
743 			SI5341_OUT_CONFIG(output),
744 			SI5341_OUT_CFG_PDN, 0);
745 	if (err < 0)
746 		return err;
747 
748 	return regmap_update_bits(output->data->regmap,
749 			SI5341_OUT_CONFIG(output),
750 			SI5341_OUT_CFG_OE, SI5341_OUT_CFG_OE);
751 }
752 
753 static unsigned long si5341_output_clk_recalc_rate(struct clk_hw *hw,
754 		unsigned long parent_rate)
755 {
756 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
757 	int err;
758 	u32 val;
759 	u32 r_divider;
760 	u8 r[3];
761 
762 	err = regmap_bulk_read(output->data->regmap,
763 			SI5341_OUT_R_REG(output), r, 3);
764 	if (err < 0)
765 		return err;
766 
767 	/* Calculate value as 24-bit integer*/
768 	r_divider = r[2] << 16 | r[1] << 8 | r[0];
769 
770 	/* If Rx_REG is zero, the divider is disabled, so return a "0" rate */
771 	if (!r_divider)
772 		return 0;
773 
774 	/* Divider is 2*(Rx_REG+1) */
775 	r_divider += 1;
776 	r_divider <<= 1;
777 
778 	err = regmap_read(output->data->regmap,
779 			SI5341_OUT_CONFIG(output), &val);
780 	if (err < 0)
781 		return err;
782 
783 	if (val & SI5341_OUT_CFG_RDIV_FORCE2)
784 		r_divider = 2;
785 
786 	return parent_rate / r_divider;
787 }
788 
789 static long si5341_output_clk_round_rate(struct clk_hw *hw, unsigned long rate,
790 		unsigned long *parent_rate)
791 {
792 	unsigned long r;
793 
794 	r = *parent_rate >> 1;
795 
796 	/* If rate is an even divisor, no changes to parent required */
797 	if (r && !(r % rate))
798 		return (long)rate;
799 
800 	if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
801 		if (rate > 200000000) {
802 			/* minimum r-divider is 2 */
803 			r = 2;
804 		} else {
805 			/* Take a parent frequency near 400 MHz */
806 			r = (400000000u / rate) & ~1;
807 		}
808 		*parent_rate = r * rate;
809 	} else {
810 		/* We cannot change our parent's rate, report what we can do */
811 		r /= rate;
812 		rate = *parent_rate / (r << 1);
813 	}
814 
815 	return rate;
816 }
817 
818 static int si5341_output_clk_set_rate(struct clk_hw *hw, unsigned long rate,
819 		unsigned long parent_rate)
820 {
821 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
822 	/* Frequency divider is (r_div + 1) * 2 */
823 	u32 r_div = (parent_rate / rate) >> 1;
824 	int err;
825 	u8 r[3];
826 
827 	if (r_div <= 1)
828 		r_div = 0;
829 	else if (r_div >= BIT(24))
830 		r_div = BIT(24) - 1;
831 	else
832 		--r_div;
833 
834 	/* For a value of "2", we set the "OUT0_RDIV_FORCE2" bit */
835 	err = regmap_update_bits(output->data->regmap,
836 			SI5341_OUT_CONFIG(output),
837 			SI5341_OUT_CFG_RDIV_FORCE2,
838 			(r_div == 0) ? SI5341_OUT_CFG_RDIV_FORCE2 : 0);
839 	if (err < 0)
840 		return err;
841 
842 	/* Always write Rx_REG, because a zero value disables the divider */
843 	r[0] = r_div ? (r_div & 0xff) : 1;
844 	r[1] = (r_div >> 8) & 0xff;
845 	r[2] = (r_div >> 16) & 0xff;
846 	err = regmap_bulk_write(output->data->regmap,
847 			SI5341_OUT_R_REG(output), r, 3);
848 
849 	return 0;
850 }
851 
852 static int si5341_output_reparent(struct clk_si5341_output *output, u8 index)
853 {
854 	return regmap_update_bits(output->data->regmap,
855 		SI5341_OUT_MUX_SEL(output), 0x07, index);
856 }
857 
858 static int si5341_output_set_parent(struct clk_hw *hw, u8 index)
859 {
860 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
861 
862 	if (index >= output->data->num_synth)
863 		return -EINVAL;
864 
865 	return si5341_output_reparent(output, index);
866 }
867 
868 static u8 si5341_output_get_parent(struct clk_hw *hw)
869 {
870 	struct clk_si5341_output *output = to_clk_si5341_output(hw);
871 	int err;
872 	u32 val;
873 
874 	err = regmap_read(output->data->regmap,
875 			SI5341_OUT_MUX_SEL(output), &val);
876 
877 	return val & 0x7;
878 }
879 
880 static const struct clk_ops si5341_output_clk_ops = {
881 	.is_prepared = si5341_output_clk_is_on,
882 	.prepare = si5341_output_clk_prepare,
883 	.unprepare = si5341_output_clk_unprepare,
884 	.recalc_rate = si5341_output_clk_recalc_rate,
885 	.round_rate = si5341_output_clk_round_rate,
886 	.set_rate = si5341_output_clk_set_rate,
887 	.set_parent = si5341_output_set_parent,
888 	.get_parent = si5341_output_get_parent,
889 };
890 
891 /*
892  * The chip can be bought in a pre-programmed version, or one can program the
893  * NVM in the chip to boot up in a preset mode. This routine tries to determine
894  * if that's the case, or if we need to reset and program everything from
895  * scratch. Returns negative error, or true/false.
896  */
897 static int si5341_is_programmed_already(struct clk_si5341 *data)
898 {
899 	int err;
900 	u8 r[4];
901 
902 	/* Read the PLL divider value, it must have a non-zero value */
903 	err = regmap_bulk_read(data->regmap, SI5341_PLL_M_DEN,
904 			r, ARRAY_SIZE(r));
905 	if (err < 0)
906 		return err;
907 
908 	return !!get_unaligned_le32(r);
909 }
910 
911 static struct clk_hw *
912 of_clk_si5341_get(struct of_phandle_args *clkspec, void *_data)
913 {
914 	struct clk_si5341 *data = _data;
915 	unsigned int idx = clkspec->args[1];
916 	unsigned int group = clkspec->args[0];
917 
918 	switch (group) {
919 	case 0:
920 		if (idx >= data->num_outputs) {
921 			dev_err(&data->i2c_client->dev,
922 				"invalid output index %u\n", idx);
923 			return ERR_PTR(-EINVAL);
924 		}
925 		return &data->clk[idx].hw;
926 	case 1:
927 		if (idx >= data->num_synth) {
928 			dev_err(&data->i2c_client->dev,
929 				"invalid synthesizer index %u\n", idx);
930 			return ERR_PTR(-EINVAL);
931 		}
932 		return &data->synth[idx].hw;
933 	case 2:
934 		if (idx > 0) {
935 			dev_err(&data->i2c_client->dev,
936 				"invalid PLL index %u\n", idx);
937 			return ERR_PTR(-EINVAL);
938 		}
939 		return &data->hw;
940 	default:
941 		dev_err(&data->i2c_client->dev, "invalid group %u\n", group);
942 		return ERR_PTR(-EINVAL);
943 	}
944 }
945 
946 static int si5341_probe_chip_id(struct clk_si5341 *data)
947 {
948 	int err;
949 	u8 reg[4];
950 	u16 model;
951 
952 	err = regmap_bulk_read(data->regmap, SI5341_PN_BASE, reg,
953 				ARRAY_SIZE(reg));
954 	if (err < 0) {
955 		dev_err(&data->i2c_client->dev, "Failed to read chip ID\n");
956 		return err;
957 	}
958 
959 	model = get_unaligned_le16(reg);
960 
961 	dev_info(&data->i2c_client->dev, "Chip: %x Grade: %u Rev: %u\n",
962 		 model, reg[2], reg[3]);
963 
964 	switch (model) {
965 	case 0x5340:
966 		data->num_outputs = SI5340_MAX_NUM_OUTPUTS;
967 		data->num_synth = SI5340_NUM_SYNTH;
968 		data->reg_output_offset = si5340_reg_output_offset;
969 		data->reg_rdiv_offset = si5340_reg_rdiv_offset;
970 		break;
971 	case 0x5341:
972 		data->num_outputs = SI5341_MAX_NUM_OUTPUTS;
973 		data->num_synth = SI5341_NUM_SYNTH;
974 		data->reg_output_offset = si5341_reg_output_offset;
975 		data->reg_rdiv_offset = si5341_reg_rdiv_offset;
976 		break;
977 	default:
978 		dev_err(&data->i2c_client->dev, "Model '%x' not supported\n",
979 			model);
980 		return -EINVAL;
981 	}
982 
983 	return 0;
984 }
985 
986 /* Read active settings into the regmap cache for later reference */
987 static int si5341_read_settings(struct clk_si5341 *data)
988 {
989 	int err;
990 	u8 i;
991 	u8 r[10];
992 
993 	err = regmap_bulk_read(data->regmap, SI5341_PLL_M_NUM, r, 10);
994 	if (err < 0)
995 		return err;
996 
997 	err = regmap_bulk_read(data->regmap,
998 				SI5341_SYNTH_N_CLK_TO_OUTX_EN, r, 3);
999 	if (err < 0)
1000 		return err;
1001 
1002 	err = regmap_bulk_read(data->regmap,
1003 				SI5341_SYNTH_N_CLK_DIS, r, 1);
1004 	if (err < 0)
1005 		return err;
1006 
1007 	for (i = 0; i < data->num_synth; ++i) {
1008 		err = regmap_bulk_read(data->regmap,
1009 					SI5341_SYNTH_N_NUM(i), r, 10);
1010 		if (err < 0)
1011 			return err;
1012 	}
1013 
1014 	for (i = 0; i < data->num_outputs; ++i) {
1015 		err = regmap_bulk_read(data->regmap,
1016 					data->reg_output_offset[i], r, 4);
1017 		if (err < 0)
1018 			return err;
1019 
1020 		err = regmap_bulk_read(data->regmap,
1021 					data->reg_rdiv_offset[i], r, 3);
1022 		if (err < 0)
1023 			return err;
1024 	}
1025 
1026 	return 0;
1027 }
1028 
1029 static int si5341_write_multiple(struct clk_si5341 *data,
1030 	const struct si5341_reg_default *values, unsigned int num_values)
1031 {
1032 	unsigned int i;
1033 	int res;
1034 
1035 	for (i = 0; i < num_values; ++i) {
1036 		res = regmap_write(data->regmap,
1037 			values[i].address, values[i].value);
1038 		if (res < 0) {
1039 			dev_err(&data->i2c_client->dev,
1040 				"Failed to write %#x:%#x\n",
1041 				values[i].address, values[i].value);
1042 			return res;
1043 		}
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static const struct si5341_reg_default si5341_preamble[] = {
1050 	{ 0x0B25, 0x00 },
1051 	{ 0x0502, 0x01 },
1052 	{ 0x0505, 0x03 },
1053 	{ 0x0957, 0x1F },
1054 	{ 0x0B4E, 0x1A },
1055 };
1056 
1057 static int si5341_send_preamble(struct clk_si5341 *data)
1058 {
1059 	int res;
1060 	u32 revision;
1061 
1062 	/* For revision 2 and up, the values are slightly different */
1063 	res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
1064 	if (res < 0)
1065 		return res;
1066 
1067 	/* Write "preamble" as specified by datasheet */
1068 	res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xD8 : 0xC0);
1069 	if (res < 0)
1070 		return res;
1071 	res = si5341_write_multiple(data,
1072 		si5341_preamble, ARRAY_SIZE(si5341_preamble));
1073 	if (res < 0)
1074 		return res;
1075 
1076 	/* Datasheet specifies a 300ms wait after sending the preamble */
1077 	msleep(300);
1078 
1079 	return 0;
1080 }
1081 
1082 /* Perform a soft reset and write post-amble */
1083 static int si5341_finalize_defaults(struct clk_si5341 *data)
1084 {
1085 	int res;
1086 	u32 revision;
1087 
1088 	res = regmap_read(data->regmap, SI5341_DEVICE_REV, &revision);
1089 	if (res < 0)
1090 		return res;
1091 
1092 	dev_dbg(&data->i2c_client->dev, "%s rev=%u\n", __func__, revision);
1093 
1094 	res = regmap_write(data->regmap, SI5341_SOFT_RST, 0x01);
1095 	if (res < 0)
1096 		return res;
1097 
1098 	/* Datasheet does not explain these nameless registers */
1099 	res = regmap_write(data->regmap, 0xB24, revision < 2 ? 0xDB : 0xC3);
1100 	if (res < 0)
1101 		return res;
1102 	res = regmap_write(data->regmap, 0x0B25, 0x02);
1103 	if (res < 0)
1104 		return res;
1105 
1106 	return 0;
1107 }
1108 
1109 
1110 static const struct regmap_range si5341_regmap_volatile_range[] = {
1111 	regmap_reg_range(0x000C, 0x0012), /* Status */
1112 	regmap_reg_range(0x001C, 0x001E), /* reset, finc/fdec */
1113 	regmap_reg_range(0x00E2, 0x00FE), /* NVM, interrupts, device ready */
1114 	/* Update bits for P divider and synth config */
1115 	regmap_reg_range(SI5341_PX_UPD, SI5341_PX_UPD),
1116 	regmap_reg_range(SI5341_SYNTH_N_UPD(0), SI5341_SYNTH_N_UPD(0)),
1117 	regmap_reg_range(SI5341_SYNTH_N_UPD(1), SI5341_SYNTH_N_UPD(1)),
1118 	regmap_reg_range(SI5341_SYNTH_N_UPD(2), SI5341_SYNTH_N_UPD(2)),
1119 	regmap_reg_range(SI5341_SYNTH_N_UPD(3), SI5341_SYNTH_N_UPD(3)),
1120 	regmap_reg_range(SI5341_SYNTH_N_UPD(4), SI5341_SYNTH_N_UPD(4)),
1121 };
1122 
1123 static const struct regmap_access_table si5341_regmap_volatile = {
1124 	.yes_ranges = si5341_regmap_volatile_range,
1125 	.n_yes_ranges = ARRAY_SIZE(si5341_regmap_volatile_range),
1126 };
1127 
1128 /* Pages 0, 1, 2, 3, 9, A, B are valid, so there are 12 pages */
1129 static const struct regmap_range_cfg si5341_regmap_ranges[] = {
1130 	{
1131 		.range_min = 0,
1132 		.range_max = SI5341_REGISTER_MAX,
1133 		.selector_reg = SI5341_PAGE,
1134 		.selector_mask = 0xff,
1135 		.selector_shift = 0,
1136 		.window_start = 0,
1137 		.window_len = 256,
1138 	},
1139 };
1140 
1141 static const struct regmap_config si5341_regmap_config = {
1142 	.reg_bits = 8,
1143 	.val_bits = 8,
1144 	.cache_type = REGCACHE_RBTREE,
1145 	.ranges = si5341_regmap_ranges,
1146 	.num_ranges = ARRAY_SIZE(si5341_regmap_ranges),
1147 	.max_register = SI5341_REGISTER_MAX,
1148 	.volatile_table = &si5341_regmap_volatile,
1149 };
1150 
1151 static int si5341_dt_parse_dt(struct i2c_client *client,
1152 	struct clk_si5341_output_config *config)
1153 {
1154 	struct device_node *child;
1155 	struct device_node *np = client->dev.of_node;
1156 	u32 num;
1157 	u32 val;
1158 
1159 	memset(config, 0, sizeof(struct clk_si5341_output_config) *
1160 				SI5341_MAX_NUM_OUTPUTS);
1161 
1162 	for_each_child_of_node(np, child) {
1163 		if (of_property_read_u32(child, "reg", &num)) {
1164 			dev_err(&client->dev, "missing reg property of %s\n",
1165 				child->name);
1166 			goto put_child;
1167 		}
1168 
1169 		if (num >= SI5341_MAX_NUM_OUTPUTS) {
1170 			dev_err(&client->dev, "invalid clkout %d\n", num);
1171 			goto put_child;
1172 		}
1173 
1174 		if (!of_property_read_u32(child, "silabs,format", &val)) {
1175 			/* Set cm and ampl conservatively to 3v3 settings */
1176 			switch (val) {
1177 			case 1: /* normal differential */
1178 				config[num].out_cm_ampl_bits = 0x33;
1179 				break;
1180 			case 2: /* low-power differential */
1181 				config[num].out_cm_ampl_bits = 0x13;
1182 				break;
1183 			case 4: /* LVCMOS */
1184 				config[num].out_cm_ampl_bits = 0x33;
1185 				/* Set SI recommended impedance for LVCMOS */
1186 				config[num].out_format_drv_bits |= 0xc0;
1187 				break;
1188 			default:
1189 				dev_err(&client->dev,
1190 					"invalid silabs,format %u for %u\n",
1191 					val, num);
1192 				goto put_child;
1193 			}
1194 			config[num].out_format_drv_bits &= ~0x07;
1195 			config[num].out_format_drv_bits |= val & 0x07;
1196 			/* Always enable the SYNC feature */
1197 			config[num].out_format_drv_bits |= 0x08;
1198 		}
1199 
1200 		if (!of_property_read_u32(child, "silabs,common-mode", &val)) {
1201 			if (val > 0xf) {
1202 				dev_err(&client->dev,
1203 					"invalid silabs,common-mode %u\n",
1204 					val);
1205 				goto put_child;
1206 			}
1207 			config[num].out_cm_ampl_bits &= 0xf0;
1208 			config[num].out_cm_ampl_bits |= val & 0x0f;
1209 		}
1210 
1211 		if (!of_property_read_u32(child, "silabs,amplitude", &val)) {
1212 			if (val > 0xf) {
1213 				dev_err(&client->dev,
1214 					"invalid silabs,amplitude %u\n",
1215 					val);
1216 				goto put_child;
1217 			}
1218 			config[num].out_cm_ampl_bits &= 0x0f;
1219 			config[num].out_cm_ampl_bits |= (val << 4) & 0xf0;
1220 		}
1221 
1222 		if (of_property_read_bool(child, "silabs,disable-high"))
1223 			config[num].out_format_drv_bits |= 0x10;
1224 
1225 		config[num].synth_master =
1226 			of_property_read_bool(child, "silabs,synth-master");
1227 
1228 		config[num].always_on =
1229 			of_property_read_bool(child, "always-on");
1230 	}
1231 
1232 	return 0;
1233 
1234 put_child:
1235 	of_node_put(child);
1236 	return -EINVAL;
1237 }
1238 
1239 /*
1240  * If not pre-configured, calculate and set the PLL configuration manually.
1241  * For low-jitter performance, the PLL should be set such that the synthesizers
1242  * only need integer division.
1243  * Without any user guidance, we'll set the PLL to 14GHz, which still allows
1244  * the chip to generate any frequency on its outputs, but jitter performance
1245  * may be sub-optimal.
1246  */
1247 static int si5341_initialize_pll(struct clk_si5341 *data)
1248 {
1249 	struct device_node *np = data->i2c_client->dev.of_node;
1250 	u32 m_num = 0;
1251 	u32 m_den = 0;
1252 	int sel;
1253 
1254 	if (of_property_read_u32(np, "silabs,pll-m-num", &m_num)) {
1255 		dev_err(&data->i2c_client->dev,
1256 			"PLL configuration requires silabs,pll-m-num\n");
1257 	}
1258 	if (of_property_read_u32(np, "silabs,pll-m-den", &m_den)) {
1259 		dev_err(&data->i2c_client->dev,
1260 			"PLL configuration requires silabs,pll-m-den\n");
1261 	}
1262 
1263 	if (!m_num || !m_den) {
1264 		dev_err(&data->i2c_client->dev,
1265 			"PLL configuration invalid, assume 14GHz\n");
1266 		sel = si5341_clk_get_selected_input(data);
1267 		if (sel < 0)
1268 			return sel;
1269 
1270 		m_den = clk_get_rate(data->input_clk[sel]) / 10;
1271 		m_num = 1400000000;
1272 	}
1273 
1274 	return si5341_encode_44_32(data->regmap,
1275 			SI5341_PLL_M_NUM, m_num, m_den);
1276 }
1277 
1278 static int si5341_clk_select_active_input(struct clk_si5341 *data)
1279 {
1280 	int res;
1281 	int err;
1282 	int i;
1283 
1284 	res = si5341_clk_get_selected_input(data);
1285 	if (res < 0)
1286 		return res;
1287 
1288 	/* If the current register setting is invalid, pick the first input */
1289 	if (!data->input_clk[res]) {
1290 		dev_dbg(&data->i2c_client->dev,
1291 			"Input %d not connected, rerouting\n", res);
1292 		res = -ENODEV;
1293 		for (i = 0; i < SI5341_NUM_INPUTS; ++i) {
1294 			if (data->input_clk[i]) {
1295 				res = i;
1296 				break;
1297 			}
1298 		}
1299 		if (res < 0) {
1300 			dev_err(&data->i2c_client->dev,
1301 				"No clock input available\n");
1302 			return res;
1303 		}
1304 	}
1305 
1306 	/* Make sure the selected clock is also enabled and routed */
1307 	err = si5341_clk_reparent(data, res);
1308 	if (err < 0)
1309 		return err;
1310 
1311 	err = clk_prepare_enable(data->input_clk[res]);
1312 	if (err < 0)
1313 		return err;
1314 
1315 	return res;
1316 }
1317 
1318 static int si5341_probe(struct i2c_client *client,
1319 		const struct i2c_device_id *id)
1320 {
1321 	struct clk_si5341 *data;
1322 	struct clk_init_data init;
1323 	struct clk *input;
1324 	const char *root_clock_name;
1325 	const char *synth_clock_names[SI5341_NUM_SYNTH];
1326 	int err;
1327 	unsigned int i;
1328 	struct clk_si5341_output_config config[SI5341_MAX_NUM_OUTPUTS];
1329 	bool initialization_required;
1330 
1331 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
1332 	if (!data)
1333 		return -ENOMEM;
1334 
1335 	data->i2c_client = client;
1336 
1337 	for (i = 0; i < SI5341_NUM_INPUTS; ++i) {
1338 		input = devm_clk_get(&client->dev, si5341_input_clock_names[i]);
1339 		if (IS_ERR(input)) {
1340 			if (PTR_ERR(input) == -EPROBE_DEFER)
1341 				return -EPROBE_DEFER;
1342 			data->input_clk_name[i] = si5341_input_clock_names[i];
1343 		} else {
1344 			data->input_clk[i] = input;
1345 			data->input_clk_name[i] = __clk_get_name(input);
1346 		}
1347 	}
1348 
1349 	err = si5341_dt_parse_dt(client, config);
1350 	if (err)
1351 		return err;
1352 
1353 	if (of_property_read_string(client->dev.of_node, "clock-output-names",
1354 			&init.name))
1355 		init.name = client->dev.of_node->name;
1356 	root_clock_name = init.name;
1357 
1358 	data->regmap = devm_regmap_init_i2c(client, &si5341_regmap_config);
1359 	if (IS_ERR(data->regmap))
1360 		return PTR_ERR(data->regmap);
1361 
1362 	i2c_set_clientdata(client, data);
1363 
1364 	err = si5341_probe_chip_id(data);
1365 	if (err < 0)
1366 		return err;
1367 
1368 	if (of_property_read_bool(client->dev.of_node, "silabs,reprogram")) {
1369 		initialization_required = true;
1370 	} else {
1371 		err = si5341_is_programmed_already(data);
1372 		if (err < 0)
1373 			return err;
1374 
1375 		initialization_required = !err;
1376 	}
1377 
1378 	if (initialization_required) {
1379 		/* Populate the regmap cache in preparation for "cache only" */
1380 		err = si5341_read_settings(data);
1381 		if (err < 0)
1382 			return err;
1383 
1384 		err = si5341_send_preamble(data);
1385 		if (err < 0)
1386 			return err;
1387 
1388 		/*
1389 		 * We intend to send all 'final' register values in a single
1390 		 * transaction. So cache all register writes until we're done
1391 		 * configuring.
1392 		 */
1393 		regcache_cache_only(data->regmap, true);
1394 
1395 		/* Write the configuration pairs from the firmware blob */
1396 		err = si5341_write_multiple(data, si5341_reg_defaults,
1397 					ARRAY_SIZE(si5341_reg_defaults));
1398 		if (err < 0)
1399 			return err;
1400 	}
1401 
1402 	/* Input must be up and running at this point */
1403 	err = si5341_clk_select_active_input(data);
1404 	if (err < 0)
1405 		return err;
1406 
1407 	if (initialization_required) {
1408 		/* PLL configuration is required */
1409 		err = si5341_initialize_pll(data);
1410 		if (err < 0)
1411 			return err;
1412 	}
1413 
1414 	/* Register the PLL */
1415 	init.parent_names = data->input_clk_name;
1416 	init.num_parents = SI5341_NUM_INPUTS;
1417 	init.ops = &si5341_clk_ops;
1418 	init.flags = 0;
1419 	data->hw.init = &init;
1420 
1421 	err = devm_clk_hw_register(&client->dev, &data->hw);
1422 	if (err) {
1423 		dev_err(&client->dev, "clock registration failed\n");
1424 		return err;
1425 	}
1426 
1427 	init.num_parents = 1;
1428 	init.parent_names = &root_clock_name;
1429 	init.ops = &si5341_synth_clk_ops;
1430 	for (i = 0; i < data->num_synth; ++i) {
1431 		synth_clock_names[i] = devm_kasprintf(&client->dev, GFP_KERNEL,
1432 				"%s.N%u", client->dev.of_node->name, i);
1433 		init.name = synth_clock_names[i];
1434 		data->synth[i].index = i;
1435 		data->synth[i].data = data;
1436 		data->synth[i].hw.init = &init;
1437 		err = devm_clk_hw_register(&client->dev, &data->synth[i].hw);
1438 		if (err) {
1439 			dev_err(&client->dev,
1440 				"synth N%u registration failed\n", i);
1441 		}
1442 	}
1443 
1444 	init.num_parents = data->num_synth;
1445 	init.parent_names = synth_clock_names;
1446 	init.ops = &si5341_output_clk_ops;
1447 	for (i = 0; i < data->num_outputs; ++i) {
1448 		init.name = kasprintf(GFP_KERNEL, "%s.%d",
1449 			client->dev.of_node->name, i);
1450 		init.flags = config[i].synth_master ? CLK_SET_RATE_PARENT : 0;
1451 		data->clk[i].index = i;
1452 		data->clk[i].data = data;
1453 		data->clk[i].hw.init = &init;
1454 		if (config[i].out_format_drv_bits & 0x07) {
1455 			regmap_write(data->regmap,
1456 				SI5341_OUT_FORMAT(&data->clk[i]),
1457 				config[i].out_format_drv_bits);
1458 			regmap_write(data->regmap,
1459 				SI5341_OUT_CM(&data->clk[i]),
1460 				config[i].out_cm_ampl_bits);
1461 		}
1462 		err = devm_clk_hw_register(&client->dev, &data->clk[i].hw);
1463 		kfree(init.name); /* clock framework made a copy of the name */
1464 		if (err) {
1465 			dev_err(&client->dev,
1466 				"output %u registration failed\n", i);
1467 			return err;
1468 		}
1469 		if (config[i].always_on)
1470 			clk_prepare(data->clk[i].hw.clk);
1471 	}
1472 
1473 	err = of_clk_add_hw_provider(client->dev.of_node, of_clk_si5341_get,
1474 			data);
1475 	if (err) {
1476 		dev_err(&client->dev, "unable to add clk provider\n");
1477 		return err;
1478 	}
1479 
1480 	if (initialization_required) {
1481 		/* Synchronize */
1482 		regcache_cache_only(data->regmap, false);
1483 		err = regcache_sync(data->regmap);
1484 		if (err < 0)
1485 			return err;
1486 
1487 		err = si5341_finalize_defaults(data);
1488 		if (err < 0)
1489 			return err;
1490 	}
1491 
1492 	/* Free the names, clk framework makes copies */
1493 	for (i = 0; i < data->num_synth; ++i)
1494 		 devm_kfree(&client->dev, (void *)synth_clock_names[i]);
1495 
1496 	return 0;
1497 }
1498 
1499 static const struct i2c_device_id si5341_id[] = {
1500 	{ "si5340", 0 },
1501 	{ "si5341", 1 },
1502 	{ }
1503 };
1504 MODULE_DEVICE_TABLE(i2c, si5341_id);
1505 
1506 static const struct of_device_id clk_si5341_of_match[] = {
1507 	{ .compatible = "silabs,si5340" },
1508 	{ .compatible = "silabs,si5341" },
1509 	{ }
1510 };
1511 MODULE_DEVICE_TABLE(of, clk_si5341_of_match);
1512 
1513 static struct i2c_driver si5341_driver = {
1514 	.driver = {
1515 		.name = "si5341",
1516 		.of_match_table = clk_si5341_of_match,
1517 	},
1518 	.probe		= si5341_probe,
1519 	.id_table	= si5341_id,
1520 };
1521 module_i2c_driver(si5341_driver);
1522 
1523 MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
1524 MODULE_DESCRIPTION("Si5341 driver");
1525 MODULE_LICENSE("GPL");
1526