xref: /openbmc/linux/drivers/clk/clk-versaclock5.c (revision bb0eb050)
1 /*
2  * Driver for IDT Versaclock 5
3  *
4  * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 /*
18  * Possible optimizations:
19  * - Use spread spectrum
20  * - Use integer divider in FOD if applicable
21  */
22 
23 #include <linux/clk.h>
24 #include <linux/clk-provider.h>
25 #include <linux/delay.h>
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/mod_devicetable.h>
29 #include <linux/module.h>
30 #include <linux/of.h>
31 #include <linux/of_platform.h>
32 #include <linux/rational.h>
33 #include <linux/regmap.h>
34 #include <linux/slab.h>
35 
36 /* VersaClock5 registers */
37 #define VC5_OTP_CONTROL				0x00
38 
39 /* Factory-reserved register block */
40 #define VC5_RSVD_DEVICE_ID			0x01
41 #define VC5_RSVD_ADC_GAIN_7_0			0x02
42 #define VC5_RSVD_ADC_GAIN_15_8			0x03
43 #define VC5_RSVD_ADC_OFFSET_7_0			0x04
44 #define VC5_RSVD_ADC_OFFSET_15_8		0x05
45 #define VC5_RSVD_TEMPY				0x06
46 #define VC5_RSVD_OFFSET_TBIN			0x07
47 #define VC5_RSVD_GAIN				0x08
48 #define VC5_RSVD_TEST_NP			0x09
49 #define VC5_RSVD_UNUSED				0x0a
50 #define VC5_RSVD_BANDGAP_TRIM_UP		0x0b
51 #define VC5_RSVD_BANDGAP_TRIM_DN		0x0c
52 #define VC5_RSVD_CLK_R_12_CLK_AMP_4		0x0d
53 #define VC5_RSVD_CLK_R_34_CLK_AMP_4		0x0e
54 #define VC5_RSVD_CLK_AMP_123			0x0f
55 
56 /* Configuration register block */
57 #define VC5_PRIM_SRC_SHDN			0x10
58 #define VC5_PRIM_SRC_SHDN_EN_XTAL		BIT(7)
59 #define VC5_PRIM_SRC_SHDN_EN_CLKIN		BIT(6)
60 #define VC5_PRIM_SRC_SHDN_SP			BIT(1)
61 #define VC5_PRIM_SRC_SHDN_EN_GBL_SHDN		BIT(0)
62 
63 #define VC5_VCO_BAND				0x11
64 #define VC5_XTAL_X1_LOAD_CAP			0x12
65 #define VC5_XTAL_X2_LOAD_CAP			0x13
66 #define VC5_REF_DIVIDER				0x15
67 #define VC5_REF_DIVIDER_SEL_PREDIV2		BIT(7)
68 #define VC5_REF_DIVIDER_REF_DIV(n)		((n) & 0x3f)
69 
70 #define VC5_VCO_CTRL_AND_PREDIV			0x16
71 #define VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV	BIT(7)
72 
73 #define VC5_FEEDBACK_INT_DIV			0x17
74 #define VC5_FEEDBACK_INT_DIV_BITS		0x18
75 #define VC5_FEEDBACK_FRAC_DIV(n)		(0x19 + (n))
76 #define VC5_RC_CONTROL0				0x1e
77 #define VC5_RC_CONTROL1				0x1f
78 /* Register 0x20 is factory reserved */
79 
80 /* Output divider control for divider 1,2,3,4 */
81 #define VC5_OUT_DIV_CONTROL(idx)	(0x21 + ((idx) * 0x10))
82 #define VC5_OUT_DIV_CONTROL_RESET	BIT(7)
83 #define VC5_OUT_DIV_CONTROL_SELB_NORM	BIT(3)
84 #define VC5_OUT_DIV_CONTROL_SEL_EXT	BIT(2)
85 #define VC5_OUT_DIV_CONTROL_INT_MODE	BIT(1)
86 #define VC5_OUT_DIV_CONTROL_EN_FOD	BIT(0)
87 
88 #define VC5_OUT_DIV_FRAC(idx, n)	(0x22 + ((idx) * 0x10) + (n))
89 #define VC5_OUT_DIV_FRAC4_OD_SCEE	BIT(1)
90 
91 #define VC5_OUT_DIV_STEP_SPREAD(idx, n)	(0x26 + ((idx) * 0x10) + (n))
92 #define VC5_OUT_DIV_SPREAD_MOD(idx, n)	(0x29 + ((idx) * 0x10) + (n))
93 #define VC5_OUT_DIV_SKEW_INT(idx, n)	(0x2b + ((idx) * 0x10) + (n))
94 #define VC5_OUT_DIV_INT(idx, n)		(0x2d + ((idx) * 0x10) + (n))
95 #define VC5_OUT_DIV_SKEW_FRAC(idx)	(0x2f + ((idx) * 0x10))
96 /* Registers 0x30, 0x40, 0x50 are factory reserved */
97 
98 /* Clock control register for clock 1,2 */
99 #define VC5_CLK_OUTPUT_CFG(idx, n)	(0x60 + ((idx) * 0x2) + (n))
100 #define VC5_CLK_OUTPUT_CFG1_EN_CLKBUF	BIT(0)
101 
102 #define VC5_CLK_OE_SHDN				0x68
103 #define VC5_CLK_OS_SHDN				0x69
104 
105 #define VC5_GLOBAL_REGISTER			0x76
106 #define VC5_GLOBAL_REGISTER_GLOBAL_RESET	BIT(5)
107 
108 /* PLL/VCO runs between 2.5 GHz and 3.0 GHz */
109 #define VC5_PLL_VCO_MIN				2500000000UL
110 #define VC5_PLL_VCO_MAX				3000000000UL
111 
112 /* VC5 Input mux settings */
113 #define VC5_MUX_IN_XIN		BIT(0)
114 #define VC5_MUX_IN_CLKIN	BIT(1)
115 
116 /* Maximum number of clk_out supported by this driver */
117 #define VC5_MAX_CLK_OUT_NUM	5
118 
119 /* Maximum number of FODs supported by this driver */
120 #define VC5_MAX_FOD_NUM	4
121 
122 /* flags to describe chip features */
123 /* chip has built-in oscilator */
124 #define VC5_HAS_INTERNAL_XTAL	BIT(0)
125 
126 /* Supported IDT VC5 models. */
127 enum vc5_model {
128 	IDT_VC5_5P49V5923,
129 	IDT_VC5_5P49V5933,
130 	IDT_VC5_5P49V5935,
131 };
132 
133 /* Structure to describe features of a particular VC5 model */
134 struct vc5_chip_info {
135 	const enum vc5_model	model;
136 	const unsigned int	clk_fod_cnt;
137 	const unsigned int	clk_out_cnt;
138 	const u32		flags;
139 };
140 
141 struct vc5_driver_data;
142 
143 struct vc5_hw_data {
144 	struct clk_hw		hw;
145 	struct vc5_driver_data	*vc5;
146 	u32			div_int;
147 	u32			div_frc;
148 	unsigned int		num;
149 };
150 
151 struct vc5_driver_data {
152 	struct i2c_client	*client;
153 	struct regmap		*regmap;
154 	const struct vc5_chip_info	*chip_info;
155 
156 	struct clk		*pin_xin;
157 	struct clk		*pin_clkin;
158 	unsigned char		clk_mux_ins;
159 	struct clk_hw		clk_mux;
160 	struct vc5_hw_data	clk_pll;
161 	struct vc5_hw_data	clk_fod[VC5_MAX_FOD_NUM];
162 	struct vc5_hw_data	clk_out[VC5_MAX_CLK_OUT_NUM];
163 };
164 
165 static const char * const vc5_mux_names[] = {
166 	"mux"
167 };
168 
169 static const char * const vc5_pll_names[] = {
170 	"pll"
171 };
172 
173 static const char * const vc5_fod_names[] = {
174 	"fod0", "fod1", "fod2", "fod3",
175 };
176 
177 static const char * const vc5_clk_out_names[] = {
178 	"out0_sel_i2cb", "out1", "out2", "out3", "out4",
179 };
180 
181 /*
182  * VersaClock5 i2c regmap
183  */
184 static bool vc5_regmap_is_writeable(struct device *dev, unsigned int reg)
185 {
186 	/* Factory reserved regs, make them read-only */
187 	if (reg <= 0xf)
188 		return false;
189 
190 	/* Factory reserved regs, make them read-only */
191 	if (reg == 0x14 || reg == 0x1c || reg == 0x1d)
192 		return false;
193 
194 	return true;
195 }
196 
197 static const struct regmap_config vc5_regmap_config = {
198 	.reg_bits = 8,
199 	.val_bits = 8,
200 	.cache_type = REGCACHE_RBTREE,
201 	.max_register = 0x76,
202 	.writeable_reg = vc5_regmap_is_writeable,
203 };
204 
205 /*
206  * VersaClock5 input multiplexer between XTAL and CLKIN divider
207  */
208 static unsigned char vc5_mux_get_parent(struct clk_hw *hw)
209 {
210 	struct vc5_driver_data *vc5 =
211 		container_of(hw, struct vc5_driver_data, clk_mux);
212 	const u8 mask = VC5_PRIM_SRC_SHDN_EN_XTAL | VC5_PRIM_SRC_SHDN_EN_CLKIN;
213 	unsigned int src;
214 
215 	regmap_read(vc5->regmap, VC5_PRIM_SRC_SHDN, &src);
216 	src &= mask;
217 
218 	if (src == VC5_PRIM_SRC_SHDN_EN_XTAL)
219 		return 0;
220 
221 	if (src == VC5_PRIM_SRC_SHDN_EN_CLKIN)
222 		return 1;
223 
224 	dev_warn(&vc5->client->dev,
225 		 "Invalid clock input configuration (%02x)\n", src);
226 	return 0;
227 }
228 
229 static int vc5_mux_set_parent(struct clk_hw *hw, u8 index)
230 {
231 	struct vc5_driver_data *vc5 =
232 		container_of(hw, struct vc5_driver_data, clk_mux);
233 	const u8 mask = VC5_PRIM_SRC_SHDN_EN_XTAL | VC5_PRIM_SRC_SHDN_EN_CLKIN;
234 	u8 src;
235 
236 	if ((index > 1) || !vc5->clk_mux_ins)
237 		return -EINVAL;
238 
239 	if (vc5->clk_mux_ins == (VC5_MUX_IN_CLKIN | VC5_MUX_IN_XIN)) {
240 		if (index == 0)
241 			src = VC5_PRIM_SRC_SHDN_EN_XTAL;
242 		if (index == 1)
243 			src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
244 	} else {
245 		if (index != 0)
246 			return -EINVAL;
247 
248 		if (vc5->clk_mux_ins == VC5_MUX_IN_XIN)
249 			src = VC5_PRIM_SRC_SHDN_EN_XTAL;
250 		if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
251 			src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
252 	}
253 
254 	return regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, mask, src);
255 }
256 
257 static unsigned long vc5_mux_recalc_rate(struct clk_hw *hw,
258 					 unsigned long parent_rate)
259 {
260 	struct vc5_driver_data *vc5 =
261 		container_of(hw, struct vc5_driver_data, clk_mux);
262 	unsigned int prediv, div;
263 
264 	regmap_read(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV, &prediv);
265 
266 	/* The bypass_prediv is set, PLL fed from Ref_in directly. */
267 	if (prediv & VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV)
268 		return parent_rate;
269 
270 	regmap_read(vc5->regmap, VC5_REF_DIVIDER, &div);
271 
272 	/* The Sel_prediv2 is set, PLL fed from prediv2 (Ref_in / 2) */
273 	if (div & VC5_REF_DIVIDER_SEL_PREDIV2)
274 		return parent_rate / 2;
275 	else
276 		return parent_rate / VC5_REF_DIVIDER_REF_DIV(div);
277 }
278 
279 static long vc5_mux_round_rate(struct clk_hw *hw, unsigned long rate,
280 			       unsigned long *parent_rate)
281 {
282 	unsigned long idiv;
283 
284 	/* PLL cannot operate with input clock above 50 MHz. */
285 	if (rate > 50000000)
286 		return -EINVAL;
287 
288 	/* CLKIN within range of PLL input, feed directly to PLL. */
289 	if (*parent_rate <= 50000000)
290 		return *parent_rate;
291 
292 	idiv = DIV_ROUND_UP(*parent_rate, rate);
293 	if (idiv > 127)
294 		return -EINVAL;
295 
296 	return *parent_rate / idiv;
297 }
298 
299 static int vc5_mux_set_rate(struct clk_hw *hw, unsigned long rate,
300 			    unsigned long parent_rate)
301 {
302 	struct vc5_driver_data *vc5 =
303 		container_of(hw, struct vc5_driver_data, clk_mux);
304 	unsigned long idiv;
305 	u8 div;
306 
307 	/* CLKIN within range of PLL input, feed directly to PLL. */
308 	if (parent_rate <= 50000000) {
309 		regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
310 				   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV,
311 				   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV);
312 		regmap_update_bits(vc5->regmap, VC5_REF_DIVIDER, 0xff, 0x00);
313 		return 0;
314 	}
315 
316 	idiv = DIV_ROUND_UP(parent_rate, rate);
317 
318 	/* We have dedicated div-2 predivider. */
319 	if (idiv == 2)
320 		div = VC5_REF_DIVIDER_SEL_PREDIV2;
321 	else
322 		div = VC5_REF_DIVIDER_REF_DIV(idiv);
323 
324 	regmap_update_bits(vc5->regmap, VC5_REF_DIVIDER, 0xff, div);
325 	regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
326 			   VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV, 0);
327 
328 	return 0;
329 }
330 
331 static const struct clk_ops vc5_mux_ops = {
332 	.set_parent	= vc5_mux_set_parent,
333 	.get_parent	= vc5_mux_get_parent,
334 	.recalc_rate	= vc5_mux_recalc_rate,
335 	.round_rate	= vc5_mux_round_rate,
336 	.set_rate	= vc5_mux_set_rate,
337 };
338 
339 /*
340  * VersaClock5 PLL/VCO
341  */
342 static unsigned long vc5_pll_recalc_rate(struct clk_hw *hw,
343 					 unsigned long parent_rate)
344 {
345 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
346 	struct vc5_driver_data *vc5 = hwdata->vc5;
347 	u32 div_int, div_frc;
348 	u8 fb[5];
349 
350 	regmap_bulk_read(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
351 
352 	div_int = (fb[0] << 4) | (fb[1] >> 4);
353 	div_frc = (fb[2] << 16) | (fb[3] << 8) | fb[4];
354 
355 	/* The PLL divider has 12 integer bits and 24 fractional bits */
356 	return (parent_rate * div_int) + ((parent_rate * div_frc) >> 24);
357 }
358 
359 static long vc5_pll_round_rate(struct clk_hw *hw, unsigned long rate,
360 			       unsigned long *parent_rate)
361 {
362 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
363 	u32 div_int;
364 	u64 div_frc;
365 
366 	if (rate < VC5_PLL_VCO_MIN)
367 		rate = VC5_PLL_VCO_MIN;
368 	if (rate > VC5_PLL_VCO_MAX)
369 		rate = VC5_PLL_VCO_MAX;
370 
371 	/* Determine integer part, which is 12 bit wide */
372 	div_int = rate / *parent_rate;
373 	if (div_int > 0xfff)
374 		rate = *parent_rate * 0xfff;
375 
376 	/* Determine best fractional part, which is 24 bit wide */
377 	div_frc = rate % *parent_rate;
378 	div_frc *= BIT(24) - 1;
379 	do_div(div_frc, *parent_rate);
380 
381 	hwdata->div_int = div_int;
382 	hwdata->div_frc = (u32)div_frc;
383 
384 	return (*parent_rate * div_int) + ((*parent_rate * div_frc) >> 24);
385 }
386 
387 static int vc5_pll_set_rate(struct clk_hw *hw, unsigned long rate,
388 			    unsigned long parent_rate)
389 {
390 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
391 	struct vc5_driver_data *vc5 = hwdata->vc5;
392 	u8 fb[5];
393 
394 	fb[0] = hwdata->div_int >> 4;
395 	fb[1] = hwdata->div_int << 4;
396 	fb[2] = hwdata->div_frc >> 16;
397 	fb[3] = hwdata->div_frc >> 8;
398 	fb[4] = hwdata->div_frc;
399 
400 	return regmap_bulk_write(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
401 }
402 
403 static const struct clk_ops vc5_pll_ops = {
404 	.recalc_rate	= vc5_pll_recalc_rate,
405 	.round_rate	= vc5_pll_round_rate,
406 	.set_rate	= vc5_pll_set_rate,
407 };
408 
409 static unsigned long vc5_fod_recalc_rate(struct clk_hw *hw,
410 					 unsigned long parent_rate)
411 {
412 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
413 	struct vc5_driver_data *vc5 = hwdata->vc5;
414 	/* VCO frequency is divided by two before entering FOD */
415 	u32 f_in = parent_rate / 2;
416 	u32 div_int, div_frc;
417 	u8 od_int[2];
418 	u8 od_frc[4];
419 
420 	regmap_bulk_read(vc5->regmap, VC5_OUT_DIV_INT(hwdata->num, 0),
421 			 od_int, 2);
422 	regmap_bulk_read(vc5->regmap, VC5_OUT_DIV_FRAC(hwdata->num, 0),
423 			 od_frc, 4);
424 
425 	div_int = (od_int[0] << 4) | (od_int[1] >> 4);
426 	div_frc = (od_frc[0] << 22) | (od_frc[1] << 14) |
427 		  (od_frc[2] << 6) | (od_frc[3] >> 2);
428 
429 	/* The PLL divider has 12 integer bits and 30 fractional bits */
430 	return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
431 }
432 
433 static long vc5_fod_round_rate(struct clk_hw *hw, unsigned long rate,
434 			       unsigned long *parent_rate)
435 {
436 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
437 	/* VCO frequency is divided by two before entering FOD */
438 	u32 f_in = *parent_rate / 2;
439 	u32 div_int;
440 	u64 div_frc;
441 
442 	/* Determine integer part, which is 12 bit wide */
443 	div_int = f_in / rate;
444 	/*
445 	 * WARNING: The clock chip does not output signal if the integer part
446 	 *          of the divider is 0xfff and fractional part is non-zero.
447 	 *          Clamp the divider at 0xffe to keep the code simple.
448 	 */
449 	if (div_int > 0xffe) {
450 		div_int = 0xffe;
451 		rate = f_in / div_int;
452 	}
453 
454 	/* Determine best fractional part, which is 30 bit wide */
455 	div_frc = f_in % rate;
456 	div_frc <<= 24;
457 	do_div(div_frc, rate);
458 
459 	hwdata->div_int = div_int;
460 	hwdata->div_frc = (u32)div_frc;
461 
462 	return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
463 }
464 
465 static int vc5_fod_set_rate(struct clk_hw *hw, unsigned long rate,
466 			    unsigned long parent_rate)
467 {
468 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
469 	struct vc5_driver_data *vc5 = hwdata->vc5;
470 	u8 data[14] = {
471 		hwdata->div_frc >> 22, hwdata->div_frc >> 14,
472 		hwdata->div_frc >> 6, hwdata->div_frc << 2,
473 		0, 0, 0, 0, 0,
474 		0, 0,
475 		hwdata->div_int >> 4, hwdata->div_int << 4,
476 		0
477 	};
478 
479 	regmap_bulk_write(vc5->regmap, VC5_OUT_DIV_FRAC(hwdata->num, 0),
480 			  data, 14);
481 
482 	/*
483 	 * Toggle magic bit in undocumented register for unknown reason.
484 	 * This is what the IDT timing commander tool does and the chip
485 	 * datasheet somewhat implies this is needed, but the register
486 	 * and the bit is not documented.
487 	 */
488 	regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
489 			   VC5_GLOBAL_REGISTER_GLOBAL_RESET, 0);
490 	regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
491 			   VC5_GLOBAL_REGISTER_GLOBAL_RESET,
492 			   VC5_GLOBAL_REGISTER_GLOBAL_RESET);
493 	return 0;
494 }
495 
496 static const struct clk_ops vc5_fod_ops = {
497 	.recalc_rate	= vc5_fod_recalc_rate,
498 	.round_rate	= vc5_fod_round_rate,
499 	.set_rate	= vc5_fod_set_rate,
500 };
501 
502 static int vc5_clk_out_prepare(struct clk_hw *hw)
503 {
504 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
505 	struct vc5_driver_data *vc5 = hwdata->vc5;
506 
507 	/* Enable the clock buffer */
508 	regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
509 			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF,
510 			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF);
511 	return 0;
512 }
513 
514 static void vc5_clk_out_unprepare(struct clk_hw *hw)
515 {
516 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
517 	struct vc5_driver_data *vc5 = hwdata->vc5;
518 
519 	/* Enable the clock buffer */
520 	regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
521 			   VC5_CLK_OUTPUT_CFG1_EN_CLKBUF, 0);
522 }
523 
524 static unsigned char vc5_clk_out_get_parent(struct clk_hw *hw)
525 {
526 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
527 	struct vc5_driver_data *vc5 = hwdata->vc5;
528 	const u8 mask = VC5_OUT_DIV_CONTROL_SELB_NORM |
529 			VC5_OUT_DIV_CONTROL_SEL_EXT |
530 			VC5_OUT_DIV_CONTROL_EN_FOD;
531 	const u8 fodclkmask = VC5_OUT_DIV_CONTROL_SELB_NORM |
532 			      VC5_OUT_DIV_CONTROL_EN_FOD;
533 	const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
534 			  VC5_OUT_DIV_CONTROL_SEL_EXT;
535 	unsigned int src;
536 
537 	regmap_read(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num), &src);
538 	src &= mask;
539 
540 	if ((src & fodclkmask) == VC5_OUT_DIV_CONTROL_EN_FOD)
541 		return 0;
542 
543 	if (src == extclk)
544 		return 1;
545 
546 	dev_warn(&vc5->client->dev,
547 		 "Invalid clock output configuration (%02x)\n", src);
548 	return 0;
549 }
550 
551 static int vc5_clk_out_set_parent(struct clk_hw *hw, u8 index)
552 {
553 	struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
554 	struct vc5_driver_data *vc5 = hwdata->vc5;
555 	const u8 mask = VC5_OUT_DIV_CONTROL_RESET |
556 			VC5_OUT_DIV_CONTROL_SELB_NORM |
557 			VC5_OUT_DIV_CONTROL_SEL_EXT |
558 			VC5_OUT_DIV_CONTROL_EN_FOD;
559 	const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
560 			  VC5_OUT_DIV_CONTROL_SEL_EXT;
561 	u8 src = VC5_OUT_DIV_CONTROL_RESET;
562 
563 	if (index == 0)
564 		src |= VC5_OUT_DIV_CONTROL_EN_FOD;
565 	else
566 		src |= extclk;
567 
568 	return regmap_update_bits(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num),
569 				  mask, src);
570 }
571 
572 static const struct clk_ops vc5_clk_out_ops = {
573 	.prepare	= vc5_clk_out_prepare,
574 	.unprepare	= vc5_clk_out_unprepare,
575 	.set_parent	= vc5_clk_out_set_parent,
576 	.get_parent	= vc5_clk_out_get_parent,
577 };
578 
579 static struct clk_hw *vc5_of_clk_get(struct of_phandle_args *clkspec,
580 				     void *data)
581 {
582 	struct vc5_driver_data *vc5 = data;
583 	unsigned int idx = clkspec->args[0];
584 
585 	if (idx >= vc5->chip_info->clk_out_cnt)
586 		return ERR_PTR(-EINVAL);
587 
588 	return &vc5->clk_out[idx].hw;
589 }
590 
591 static int vc5_map_index_to_output(const enum vc5_model model,
592 				   const unsigned int n)
593 {
594 	switch (model) {
595 	case IDT_VC5_5P49V5933:
596 		return (n == 0) ? 0 : 3;
597 	case IDT_VC5_5P49V5923:
598 	case IDT_VC5_5P49V5935:
599 	default:
600 		return n;
601 	}
602 }
603 
604 static const struct of_device_id clk_vc5_of_match[];
605 
606 static int vc5_probe(struct i2c_client *client,
607 		     const struct i2c_device_id *id)
608 {
609 	struct vc5_driver_data *vc5;
610 	struct clk_init_data init;
611 	const char *parent_names[2];
612 	unsigned int n, idx = 0;
613 	int ret;
614 
615 	vc5 = devm_kzalloc(&client->dev, sizeof(*vc5), GFP_KERNEL);
616 	if (vc5 == NULL)
617 		return -ENOMEM;
618 
619 	i2c_set_clientdata(client, vc5);
620 	vc5->client = client;
621 	vc5->chip_info = of_device_get_match_data(&client->dev);
622 
623 	vc5->pin_xin = devm_clk_get(&client->dev, "xin");
624 	if (PTR_ERR(vc5->pin_xin) == -EPROBE_DEFER)
625 		return -EPROBE_DEFER;
626 
627 	vc5->pin_clkin = devm_clk_get(&client->dev, "clkin");
628 	if (PTR_ERR(vc5->pin_clkin) == -EPROBE_DEFER)
629 		return -EPROBE_DEFER;
630 
631 	vc5->regmap = devm_regmap_init_i2c(client, &vc5_regmap_config);
632 	if (IS_ERR(vc5->regmap)) {
633 		dev_err(&client->dev, "failed to allocate register map\n");
634 		return PTR_ERR(vc5->regmap);
635 	}
636 
637 	/* Register clock input mux */
638 	memset(&init, 0, sizeof(init));
639 
640 	if (!IS_ERR(vc5->pin_xin)) {
641 		vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
642 		parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
643 	} else if (vc5->chip_info->flags & VC5_HAS_INTERNAL_XTAL) {
644 		vc5->pin_xin = clk_register_fixed_rate(&client->dev,
645 						       "internal-xtal", NULL,
646 						       0, 25000000);
647 		if (IS_ERR(vc5->pin_xin))
648 			return PTR_ERR(vc5->pin_xin);
649 		vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
650 		parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
651 	}
652 
653 	if (!IS_ERR(vc5->pin_clkin)) {
654 		vc5->clk_mux_ins |= VC5_MUX_IN_CLKIN;
655 		parent_names[init.num_parents++] =
656 			__clk_get_name(vc5->pin_clkin);
657 	}
658 
659 	if (!init.num_parents) {
660 		dev_err(&client->dev, "no input clock specified!\n");
661 		return -EINVAL;
662 	}
663 
664 	init.name = vc5_mux_names[0];
665 	init.ops = &vc5_mux_ops;
666 	init.flags = 0;
667 	init.parent_names = parent_names;
668 	vc5->clk_mux.init = &init;
669 	ret = devm_clk_hw_register(&client->dev, &vc5->clk_mux);
670 	if (ret) {
671 		dev_err(&client->dev, "unable to register %s\n", init.name);
672 		goto err_clk;
673 	}
674 
675 	/* Register PLL */
676 	memset(&init, 0, sizeof(init));
677 	init.name = vc5_pll_names[0];
678 	init.ops = &vc5_pll_ops;
679 	init.flags = CLK_SET_RATE_PARENT;
680 	init.parent_names = vc5_mux_names;
681 	init.num_parents = 1;
682 	vc5->clk_pll.num = 0;
683 	vc5->clk_pll.vc5 = vc5;
684 	vc5->clk_pll.hw.init = &init;
685 	ret = devm_clk_hw_register(&client->dev, &vc5->clk_pll.hw);
686 	if (ret) {
687 		dev_err(&client->dev, "unable to register %s\n", init.name);
688 		goto err_clk;
689 	}
690 
691 	/* Register FODs */
692 	for (n = 0; n < vc5->chip_info->clk_fod_cnt; n++) {
693 		idx = vc5_map_index_to_output(vc5->chip_info->model, n);
694 		memset(&init, 0, sizeof(init));
695 		init.name = vc5_fod_names[idx];
696 		init.ops = &vc5_fod_ops;
697 		init.flags = CLK_SET_RATE_PARENT;
698 		init.parent_names = vc5_pll_names;
699 		init.num_parents = 1;
700 		vc5->clk_fod[n].num = idx;
701 		vc5->clk_fod[n].vc5 = vc5;
702 		vc5->clk_fod[n].hw.init = &init;
703 		ret = devm_clk_hw_register(&client->dev, &vc5->clk_fod[n].hw);
704 		if (ret) {
705 			dev_err(&client->dev, "unable to register %s\n",
706 				init.name);
707 			goto err_clk;
708 		}
709 	}
710 
711 	/* Register MUX-connected OUT0_I2C_SELB output */
712 	memset(&init, 0, sizeof(init));
713 	init.name = vc5_clk_out_names[0];
714 	init.ops = &vc5_clk_out_ops;
715 	init.flags = CLK_SET_RATE_PARENT;
716 	init.parent_names = vc5_mux_names;
717 	init.num_parents = 1;
718 	vc5->clk_out[0].num = idx;
719 	vc5->clk_out[0].vc5 = vc5;
720 	vc5->clk_out[0].hw.init = &init;
721 	ret = devm_clk_hw_register(&client->dev, &vc5->clk_out[0].hw);
722 	if (ret) {
723 		dev_err(&client->dev, "unable to register %s\n",
724 			init.name);
725 		goto err_clk;
726 	}
727 
728 	/* Register FOD-connected OUTx outputs */
729 	for (n = 1; n < vc5->chip_info->clk_out_cnt; n++) {
730 		idx = vc5_map_index_to_output(vc5->chip_info->model, n - 1);
731 		parent_names[0] = vc5_fod_names[idx];
732 		if (n == 1)
733 			parent_names[1] = vc5_mux_names[0];
734 		else
735 			parent_names[1] = vc5_clk_out_names[n - 1];
736 
737 		memset(&init, 0, sizeof(init));
738 		init.name = vc5_clk_out_names[idx + 1];
739 		init.ops = &vc5_clk_out_ops;
740 		init.flags = CLK_SET_RATE_PARENT;
741 		init.parent_names = parent_names;
742 		init.num_parents = 2;
743 		vc5->clk_out[n].num = idx;
744 		vc5->clk_out[n].vc5 = vc5;
745 		vc5->clk_out[n].hw.init = &init;
746 		ret = devm_clk_hw_register(&client->dev,
747 					   &vc5->clk_out[n].hw);
748 		if (ret) {
749 			dev_err(&client->dev, "unable to register %s\n",
750 				init.name);
751 			goto err_clk;
752 		}
753 	}
754 
755 	ret = of_clk_add_hw_provider(client->dev.of_node, vc5_of_clk_get, vc5);
756 	if (ret) {
757 		dev_err(&client->dev, "unable to add clk provider\n");
758 		goto err_clk;
759 	}
760 
761 	return 0;
762 
763 err_clk:
764 	if (vc5->chip_info->flags & VC5_HAS_INTERNAL_XTAL)
765 		clk_unregister_fixed_rate(vc5->pin_xin);
766 	return ret;
767 }
768 
769 static int vc5_remove(struct i2c_client *client)
770 {
771 	struct vc5_driver_data *vc5 = i2c_get_clientdata(client);
772 
773 	of_clk_del_provider(client->dev.of_node);
774 
775 	if (vc5->chip_info->flags & VC5_HAS_INTERNAL_XTAL)
776 		clk_unregister_fixed_rate(vc5->pin_xin);
777 
778 	return 0;
779 }
780 
781 static const struct vc5_chip_info idt_5p49v5923_info = {
782 	.model = IDT_VC5_5P49V5923,
783 	.clk_fod_cnt = 2,
784 	.clk_out_cnt = 3,
785 	.flags = 0,
786 };
787 
788 static const struct vc5_chip_info idt_5p49v5933_info = {
789 	.model = IDT_VC5_5P49V5933,
790 	.clk_fod_cnt = 2,
791 	.clk_out_cnt = 3,
792 	.flags = VC5_HAS_INTERNAL_XTAL,
793 };
794 
795 static const struct vc5_chip_info idt_5p49v5935_info = {
796 	.model = IDT_VC5_5P49V5935,
797 	.clk_fod_cnt = 4,
798 	.clk_out_cnt = 5,
799 	.flags = VC5_HAS_INTERNAL_XTAL,
800 };
801 
802 static const struct i2c_device_id vc5_id[] = {
803 	{ "5p49v5923", .driver_data = IDT_VC5_5P49V5923 },
804 	{ "5p49v5933", .driver_data = IDT_VC5_5P49V5933 },
805 	{ "5p49v5935", .driver_data = IDT_VC5_5P49V5935 },
806 	{ }
807 };
808 MODULE_DEVICE_TABLE(i2c, vc5_id);
809 
810 static const struct of_device_id clk_vc5_of_match[] = {
811 	{ .compatible = "idt,5p49v5923", .data = &idt_5p49v5923_info },
812 	{ .compatible = "idt,5p49v5933", .data = &idt_5p49v5933_info },
813 	{ .compatible = "idt,5p49v5935", .data = &idt_5p49v5935_info },
814 	{ },
815 };
816 MODULE_DEVICE_TABLE(of, clk_vc5_of_match);
817 
818 static struct i2c_driver vc5_driver = {
819 	.driver = {
820 		.name = "vc5",
821 		.of_match_table = clk_vc5_of_match,
822 	},
823 	.probe		= vc5_probe,
824 	.remove		= vc5_remove,
825 	.id_table	= vc5_id,
826 };
827 module_i2c_driver(vc5_driver);
828 
829 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
830 MODULE_DESCRIPTION("IDT VersaClock 5 driver");
831 MODULE_LICENSE("GPL");
832