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