1 // SPDX-License-Identifier: GPL-2.0-or-later
7  * Copyright (C) 2011 - 2021 Xilinx Inc.
14 #include <linux/clk-provider.h>
64  * @hw:	Clock hw struct
69  * @n1:		Clock divider N1
70  * @hs_div:	Clock divider HSDIV
71  * @rfreq:	Clock multiplier RFREQ
72  * @frequency:	Current output frequency
90  * si570_get_divs() - Read clock dividers from HW
92  * @rfreq:	Fractional multiplier (output)
93  * @n1:		Divider N1 (output)
94  * @hs_div:	Divider HSDIV (output)
97  * Retrieve clock dividers and multipliers from the HW.
106 	err = regmap_bulk_read(data->regmap, SI570_REG_HS_N1 + data->div_offset,  in si570_get_divs()
128  * si570_get_defaults() - Get default values
130  * @fout:	Factory frequency output
141 		regmap_write(data->regmap, SI570_REG_CONTROL,  in si570_get_defaults()
144 	err = si570_get_divs(data, &data->rfreq, &data->n1, &data->hs_div);  in si570_get_defaults()
152 	fdco = fout * data->n1 * data->hs_div;  in si570_get_defaults()
154 		data->fxtal = div64_u64(fdco << 24, data->rfreq >> 4);  in si570_get_defaults()
156 		data->fxtal = div64_u64(fdco << 28, data->rfreq);  in si570_get_defaults()
158 	data->frequency = fout;  in si570_get_defaults()
164  * si570_update_rfreq() - Update clock multiplier
172 	reg[0] = ((data->n1 - 1) << 6) |  in si570_update_rfreq()
173 		((data->rfreq >> 32) & RFREQ_37_32_MASK);  in si570_update_rfreq()
174 	reg[1] = (data->rfreq >> 24) & 0xff;  in si570_update_rfreq()
175 	reg[2] = (data->rfreq >> 16) & 0xff;  in si570_update_rfreq()
176 	reg[3] = (data->rfreq >> 8) & 0xff;  in si570_update_rfreq()
177 	reg[4] = data->rfreq & 0xff;  in si570_update_rfreq()
179 	return regmap_bulk_write(data->regmap, SI570_REG_N1_RFREQ0 +  in si570_update_rfreq()
180 			data->div_offset, reg, ARRAY_SIZE(reg));  in si570_update_rfreq()
184  * si570_calc_divs() - Calculate clock dividers
187  * @out_rfreq:	RFREG fractional multiplier (output)
188  * @out_n1:	Clock divider N1 (output)
189  * @out_hs_div:	Clock divider HSDIV (output)
192  * Calculate the clock dividers (@out_hs_div, @out_n1) and clock multiplier
216 				*out_rfreq = div64_u64(fdco << 28, data->fxtal);  in si570_calc_divs()
224 		return -EINVAL;  in si570_calc_divs()
239 		dev_err(&data->i2c_client->dev, "unable to recalc rate\n");  in si570_recalc_rate()
240 		return data->frequency;  in si570_recalc_rate()
244 	rate = (data->fxtal * rfreq) >> 28;  in si570_recalc_rate()
257 	if (!req->rate) {  in si570_determine_rate()
258 		req->rate = 0;  in si570_determine_rate()
263 	if (div64_u64(abs(req->rate - data->frequency) * 10000LL,  in si570_determine_rate()
264 				data->frequency) < 35) {  in si570_determine_rate()
265 		rfreq = div64_u64((data->rfreq * req->rate) +  in si570_determine_rate()
266 				  div64_u64(data->frequency, 2),  in si570_determine_rate()
267 				  data->frequency);  in si570_determine_rate()
268 		n1 = data->n1;  in si570_determine_rate()
269 		hs_div = data->hs_div;  in si570_determine_rate()
272 		err = si570_calc_divs(req->rate, data, &rfreq, &n1, &hs_div);  in si570_determine_rate()
274 			dev_err(&data->i2c_client->dev,  in si570_determine_rate()
276 			req->rate = 0;  in si570_determine_rate()
286  * si570_set_frequency() - Adjust output frequency
291  * Update output frequency for big frequency changes (> 3,500 ppm).
297 	err = si570_calc_divs(frequency, data, &data->rfreq, &data->n1,  in si570_set_frequency()
298 			&data->hs_div);  in si570_set_frequency()
303 	 * The DCO reg should be accessed with a read-modify-write operation  in si570_set_frequency()
306 	regmap_write(data->regmap, SI570_REG_FREEZE_DCO, SI570_FREEZE_DCO);  in si570_set_frequency()
307 	regmap_write(data->regmap, SI570_REG_HS_N1 + data->div_offset,  in si570_set_frequency()
308 			((data->hs_div - HS_DIV_OFFSET) << HS_DIV_SHIFT) |  in si570_set_frequency()
309 			(((data->n1 - 1) >> 2) & N1_6_2_MASK));  in si570_set_frequency()
311 	regmap_write(data->regmap, SI570_REG_FREEZE_DCO, 0);  in si570_set_frequency()
312 	regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_NEWFREQ);  in si570_set_frequency()
321  * si570_set_frequency_small() - Adjust output frequency
326  * Update output frequency for small frequency changes (< 3,500 ppm).
332 	 * This is a re-implementation of DIV_ROUND_CLOSEST  in si570_set_frequency_small()
336 	data->rfreq = div64_u64((data->rfreq * frequency) +  in si570_set_frequency_small()
337 			div_u64(data->frequency, 2), data->frequency);  in si570_set_frequency_small()
338 	regmap_write(data->regmap, SI570_REG_CONTROL, SI570_CNTRL_FREEZE_M);  in si570_set_frequency_small()
340 	regmap_write(data->regmap, SI570_REG_CONTROL, 0);  in si570_set_frequency_small()
352 	struct i2c_client *client = data->i2c_client;  in si570_set_rate()
355 	if (rate < SI570_MIN_FREQ || rate > data->info->max_freq) {  in si570_set_rate()
356 		dev_err(&client->dev,  in si570_set_rate()
358 		return -EINVAL;  in si570_set_rate()
361 	if (div64_u64(abs(rate - data->frequency) * 10000LL,  in si570_set_rate()
362 				data->frequency) < 35)  in si570_set_rate()
370 	data->frequency = rate;  in si570_set_rate()
420 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);  in si570_probe()
422 		return -ENOMEM;  in si570_probe()
427 	data->hw.init = &init;  in si570_probe()
428 	data->i2c_client = client;  in si570_probe()
430 	data->info = i2c_get_match_data(client);  in si570_probe()
431 	if (data->info->has_temperature_stability) {  in si570_probe()
432 		err = of_property_read_u32(client->dev.of_node,  in si570_probe()
433 				"temperature-stability", &stability);  in si570_probe()
435 			dev_err(&client->dev,  in si570_probe()
436 				  "'temperature-stability' property missing\n");  in si570_probe()
441 			data->div_offset = SI570_DIV_OFFSET_7PPM;  in si570_probe()
444 	if (of_property_read_string(client->dev.of_node, "clock-output-names",  in si570_probe()
445 			&init.name))  in si570_probe()
446 		init.name = client->dev.of_node->name;  in si570_probe()
448 	err = of_property_read_u32(client->dev.of_node, "factory-fout",  in si570_probe()
451 		dev_err(&client->dev, "'factory-fout' property missing\n");  in si570_probe()
455 	skip_recall = of_property_read_bool(client->dev.of_node,  in si570_probe()
456 					    "silabs,skip-recall");  in si570_probe()
458 	data->regmap = devm_regmap_init_i2c(client, &si570_regmap_config);  in si570_probe()
459 	if (IS_ERR(data->regmap)) {  in si570_probe()
460 		dev_err(&client->dev, "failed to allocate register map\n");  in si570_probe()
461 		return PTR_ERR(data->regmap);  in si570_probe()
469 	err = devm_clk_hw_register(&client->dev, &data->hw);  in si570_probe()
471 		dev_err(&client->dev, "clock registration failed\n");  in si570_probe()
474 	err = devm_of_clk_add_hw_provider(&client->dev, of_clk_hw_simple_get,  in si570_probe()
475 					  &data->hw);  in si570_probe()
477 		dev_err(&client->dev, "unable to add clk provider\n");  in si570_probe()
481 	/* Read the requested initial output frequency from device tree */  in si570_probe()
482 	if (!of_property_read_u32(client->dev.of_node, "clock-frequency",  in si570_probe()
484 		err = clk_set_rate(data->hw.clk, initial_fout);  in si570_probe()
490 	dev_info(&client->dev, "registered, current frequency %llu Hz\n",  in si570_probe()
491 			data->frequency);  in si570_probe()
525 		.name = "si570",