1 // SPDX-License-Identifier: GPL-2.0-only
2 //
3 // Copyright (c) 2021 Samuel Holland <samuel@sholland.org>
4 //
5 
6 #include <linux/clk.h>
7 #include <linux/clk-provider.h>
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/of_device.h>
11 
12 #include <linux/clk/sunxi-ng.h>
13 
14 #include "ccu_common.h"
15 
16 #include "ccu_div.h"
17 #include "ccu_gate.h"
18 #include "ccu_mux.h"
19 
20 #include "ccu-sun6i-rtc.h"
21 
22 #define IOSC_ACCURACY			300000000 /* 30% */
23 #define IOSC_RATE			16000000
24 
25 #define LOSC_RATE			32768
26 #define LOSC_RATE_SHIFT			15
27 
28 #define LOSC_CTRL_REG			0x0
29 #define LOSC_CTRL_KEY			0x16aa0000
30 
31 #define IOSC_32K_CLK_DIV_REG		0x8
32 #define IOSC_32K_CLK_DIV		GENMASK(4, 0)
33 #define IOSC_32K_PRE_DIV		32
34 
35 #define IOSC_CLK_CALI_REG		0xc
36 #define IOSC_CLK_CALI_DIV_ONES		22
37 #define IOSC_CLK_CALI_EN		BIT(1)
38 #define IOSC_CLK_CALI_SRC_SEL		BIT(0)
39 
40 #define LOSC_OUT_GATING_REG		0x60
41 
42 #define DCXO_CTRL_REG			0x160
43 #define DCXO_CTRL_CLK16M_RC_EN		BIT(0)
44 
45 struct sun6i_rtc_match_data {
46 	bool				have_ext_osc32k		: 1;
47 	bool				have_iosc_calibration	: 1;
48 	bool				rtc_32k_single_parent	: 1;
49 	const struct clk_parent_data	*osc32k_fanout_parents;
50 	u8				osc32k_fanout_nparents;
51 };
52 
53 static bool have_iosc_calibration;
54 
ccu_iosc_enable(struct clk_hw * hw)55 static int ccu_iosc_enable(struct clk_hw *hw)
56 {
57 	struct ccu_common *cm = hw_to_ccu_common(hw);
58 
59 	return ccu_gate_helper_enable(cm, DCXO_CTRL_CLK16M_RC_EN);
60 }
61 
ccu_iosc_disable(struct clk_hw * hw)62 static void ccu_iosc_disable(struct clk_hw *hw)
63 {
64 	struct ccu_common *cm = hw_to_ccu_common(hw);
65 
66 	return ccu_gate_helper_disable(cm, DCXO_CTRL_CLK16M_RC_EN);
67 }
68 
ccu_iosc_is_enabled(struct clk_hw * hw)69 static int ccu_iosc_is_enabled(struct clk_hw *hw)
70 {
71 	struct ccu_common *cm = hw_to_ccu_common(hw);
72 
73 	return ccu_gate_helper_is_enabled(cm, DCXO_CTRL_CLK16M_RC_EN);
74 }
75 
ccu_iosc_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)76 static unsigned long ccu_iosc_recalc_rate(struct clk_hw *hw,
77 					  unsigned long parent_rate)
78 {
79 	struct ccu_common *cm = hw_to_ccu_common(hw);
80 
81 	if (have_iosc_calibration) {
82 		u32 reg = readl(cm->base + IOSC_CLK_CALI_REG);
83 
84 		/*
85 		 * Recover the IOSC frequency by shifting the ones place of
86 		 * (fixed-point divider * 32768) into bit zero.
87 		 */
88 		if (reg & IOSC_CLK_CALI_EN)
89 			return reg >> (IOSC_CLK_CALI_DIV_ONES - LOSC_RATE_SHIFT);
90 	}
91 
92 	return IOSC_RATE;
93 }
94 
ccu_iosc_recalc_accuracy(struct clk_hw * hw,unsigned long parent_accuracy)95 static unsigned long ccu_iosc_recalc_accuracy(struct clk_hw *hw,
96 					      unsigned long parent_accuracy)
97 {
98 	return IOSC_ACCURACY;
99 }
100 
101 static const struct clk_ops ccu_iosc_ops = {
102 	.enable			= ccu_iosc_enable,
103 	.disable		= ccu_iosc_disable,
104 	.is_enabled		= ccu_iosc_is_enabled,
105 	.recalc_rate		= ccu_iosc_recalc_rate,
106 	.recalc_accuracy	= ccu_iosc_recalc_accuracy,
107 };
108 
109 static struct ccu_common iosc_clk = {
110 	.reg		= DCXO_CTRL_REG,
111 	.hw.init	= CLK_HW_INIT_NO_PARENT("iosc", &ccu_iosc_ops,
112 						CLK_GET_RATE_NOCACHE),
113 };
114 
ccu_iosc_32k_prepare(struct clk_hw * hw)115 static int ccu_iosc_32k_prepare(struct clk_hw *hw)
116 {
117 	struct ccu_common *cm = hw_to_ccu_common(hw);
118 	u32 val;
119 
120 	if (!have_iosc_calibration)
121 		return 0;
122 
123 	val = readl(cm->base + IOSC_CLK_CALI_REG);
124 	writel(val | IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL,
125 	       cm->base + IOSC_CLK_CALI_REG);
126 
127 	return 0;
128 }
129 
ccu_iosc_32k_unprepare(struct clk_hw * hw)130 static void ccu_iosc_32k_unprepare(struct clk_hw *hw)
131 {
132 	struct ccu_common *cm = hw_to_ccu_common(hw);
133 	u32 val;
134 
135 	if (!have_iosc_calibration)
136 		return;
137 
138 	val = readl(cm->base + IOSC_CLK_CALI_REG);
139 	writel(val & ~(IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL),
140 	       cm->base + IOSC_CLK_CALI_REG);
141 }
142 
ccu_iosc_32k_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)143 static unsigned long ccu_iosc_32k_recalc_rate(struct clk_hw *hw,
144 					      unsigned long parent_rate)
145 {
146 	struct ccu_common *cm = hw_to_ccu_common(hw);
147 	u32 val;
148 
149 	if (have_iosc_calibration) {
150 		val = readl(cm->base + IOSC_CLK_CALI_REG);
151 
152 		/* Assume the calibrated 32k clock is accurate. */
153 		if (val & IOSC_CLK_CALI_SRC_SEL)
154 			return LOSC_RATE;
155 	}
156 
157 	val = readl(cm->base + IOSC_32K_CLK_DIV_REG) & IOSC_32K_CLK_DIV;
158 
159 	return parent_rate / IOSC_32K_PRE_DIV / (val + 1);
160 }
161 
ccu_iosc_32k_recalc_accuracy(struct clk_hw * hw,unsigned long parent_accuracy)162 static unsigned long ccu_iosc_32k_recalc_accuracy(struct clk_hw *hw,
163 						  unsigned long parent_accuracy)
164 {
165 	struct ccu_common *cm = hw_to_ccu_common(hw);
166 	u32 val;
167 
168 	if (have_iosc_calibration) {
169 		val = readl(cm->base + IOSC_CLK_CALI_REG);
170 
171 		/* Assume the calibrated 32k clock is accurate. */
172 		if (val & IOSC_CLK_CALI_SRC_SEL)
173 			return 0;
174 	}
175 
176 	return parent_accuracy;
177 }
178 
179 static const struct clk_ops ccu_iosc_32k_ops = {
180 	.prepare		= ccu_iosc_32k_prepare,
181 	.unprepare		= ccu_iosc_32k_unprepare,
182 	.recalc_rate		= ccu_iosc_32k_recalc_rate,
183 	.recalc_accuracy	= ccu_iosc_32k_recalc_accuracy,
184 };
185 
186 static struct ccu_common iosc_32k_clk = {
187 	.hw.init	= CLK_HW_INIT_HW("iosc-32k", &iosc_clk.hw,
188 					 &ccu_iosc_32k_ops,
189 					 CLK_GET_RATE_NOCACHE),
190 };
191 
192 static const struct clk_hw *ext_osc32k[] = { NULL }; /* updated during probe */
193 
194 static SUNXI_CCU_GATE_HWS(ext_osc32k_gate_clk, "ext-osc32k-gate",
195 			  ext_osc32k, 0x0, BIT(4), 0);
196 
197 static const struct clk_hw *osc32k_parents[] = {
198 	&iosc_32k_clk.hw,
199 	&ext_osc32k_gate_clk.common.hw
200 };
201 
202 static struct clk_init_data osc32k_init_data = {
203 	.name		= "osc32k",
204 	.ops		= &ccu_mux_ops,
205 	.parent_hws	= osc32k_parents,
206 	.num_parents	= ARRAY_SIZE(osc32k_parents), /* updated during probe */
207 };
208 
209 static struct ccu_mux osc32k_clk = {
210 	.mux	= _SUNXI_CCU_MUX(0, 1),
211 	.common	= {
212 		.reg		= LOSC_CTRL_REG,
213 		.features	= CCU_FEATURE_KEY_FIELD,
214 		.hw.init	= &osc32k_init_data,
215 	},
216 };
217 
218 /* This falls back to the global name for fwnodes without a named reference. */
219 static const struct clk_parent_data osc24M[] = {
220 	{ .fw_name = "hosc", .name = "osc24M" }
221 };
222 
223 static struct ccu_gate osc24M_32k_clk = {
224 	.enable	= BIT(16),
225 	.common	= {
226 		.reg		= LOSC_OUT_GATING_REG,
227 		.prediv		= 750,
228 		.features	= CCU_FEATURE_ALL_PREDIV,
229 		.hw.init	= CLK_HW_INIT_PARENTS_DATA("osc24M-32k", osc24M,
230 							   &ccu_gate_ops, 0),
231 	},
232 };
233 
234 static const struct clk_hw *rtc_32k_parents[] = {
235 	&osc32k_clk.common.hw,
236 	&osc24M_32k_clk.common.hw
237 };
238 
239 static struct clk_init_data rtc_32k_init_data = {
240 	.name		= "rtc-32k",
241 	.ops		= &ccu_mux_ops,
242 	.parent_hws	= rtc_32k_parents,
243 	.num_parents	= ARRAY_SIZE(rtc_32k_parents), /* updated during probe */
244 	.flags		= CLK_IS_CRITICAL,
245 };
246 
247 static struct ccu_mux rtc_32k_clk = {
248 	.mux	= _SUNXI_CCU_MUX(1, 1),
249 	.common	= {
250 		.reg		= LOSC_CTRL_REG,
251 		.features	= CCU_FEATURE_KEY_FIELD,
252 		.hw.init	= &rtc_32k_init_data,
253 	},
254 };
255 
256 static struct clk_init_data osc32k_fanout_init_data = {
257 	.name		= "osc32k-fanout",
258 	.ops		= &ccu_mux_ops,
259 	/* parents are set during probe */
260 };
261 
262 static struct ccu_mux osc32k_fanout_clk = {
263 	.enable	= BIT(0),
264 	.mux	= _SUNXI_CCU_MUX(1, 2),
265 	.common	= {
266 		.reg		= LOSC_OUT_GATING_REG,
267 		.hw.init	= &osc32k_fanout_init_data,
268 	},
269 };
270 
271 static struct ccu_common *sun6i_rtc_ccu_clks[] = {
272 	&iosc_clk,
273 	&iosc_32k_clk,
274 	&ext_osc32k_gate_clk.common,
275 	&osc32k_clk.common,
276 	&osc24M_32k_clk.common,
277 	&rtc_32k_clk.common,
278 	&osc32k_fanout_clk.common,
279 };
280 
281 static struct clk_hw_onecell_data sun6i_rtc_ccu_hw_clks = {
282 	.num = CLK_NUMBER,
283 	.hws = {
284 		[CLK_OSC32K]		= &osc32k_clk.common.hw,
285 		[CLK_OSC32K_FANOUT]	= &osc32k_fanout_clk.common.hw,
286 		[CLK_IOSC]		= &iosc_clk.hw,
287 		[CLK_IOSC_32K]		= &iosc_32k_clk.hw,
288 		[CLK_EXT_OSC32K_GATE]	= &ext_osc32k_gate_clk.common.hw,
289 		[CLK_OSC24M_32K]	= &osc24M_32k_clk.common.hw,
290 		[CLK_RTC_32K]		= &rtc_32k_clk.common.hw,
291 	},
292 };
293 
294 static const struct sunxi_ccu_desc sun6i_rtc_ccu_desc = {
295 	.ccu_clks	= sun6i_rtc_ccu_clks,
296 	.num_ccu_clks	= ARRAY_SIZE(sun6i_rtc_ccu_clks),
297 
298 	.hw_clks	= &sun6i_rtc_ccu_hw_clks,
299 };
300 
301 static const struct clk_parent_data sun50i_h616_osc32k_fanout_parents[] = {
302 	{ .hw = &osc32k_clk.common.hw },
303 	{ .fw_name = "pll-32k" },
304 	{ .hw = &osc24M_32k_clk.common.hw }
305 };
306 
307 static const struct clk_parent_data sun50i_r329_osc32k_fanout_parents[] = {
308 	{ .hw = &osc32k_clk.common.hw },
309 	{ .hw = &ext_osc32k_gate_clk.common.hw },
310 	{ .hw = &osc24M_32k_clk.common.hw }
311 };
312 
313 static const struct sun6i_rtc_match_data sun50i_h616_rtc_ccu_data = {
314 	.have_iosc_calibration	= true,
315 	.rtc_32k_single_parent	= true,
316 	.osc32k_fanout_parents	= sun50i_h616_osc32k_fanout_parents,
317 	.osc32k_fanout_nparents	= ARRAY_SIZE(sun50i_h616_osc32k_fanout_parents),
318 };
319 
320 static const struct sun6i_rtc_match_data sun50i_r329_rtc_ccu_data = {
321 	.have_ext_osc32k	= true,
322 	.osc32k_fanout_parents	= sun50i_r329_osc32k_fanout_parents,
323 	.osc32k_fanout_nparents	= ARRAY_SIZE(sun50i_r329_osc32k_fanout_parents),
324 };
325 
326 static const struct of_device_id sun6i_rtc_ccu_match[] = {
327 	{
328 		.compatible	= "allwinner,sun50i-h616-rtc",
329 		.data		= &sun50i_h616_rtc_ccu_data,
330 	},
331 	{
332 		.compatible	= "allwinner,sun50i-r329-rtc",
333 		.data		= &sun50i_r329_rtc_ccu_data,
334 	},
335 	{},
336 };
337 
sun6i_rtc_ccu_probe(struct device * dev,void __iomem * reg)338 int sun6i_rtc_ccu_probe(struct device *dev, void __iomem *reg)
339 {
340 	const struct sun6i_rtc_match_data *data;
341 	struct clk *ext_osc32k_clk = NULL;
342 	const struct of_device_id *match;
343 
344 	/* This driver is only used for newer variants of the hardware. */
345 	match = of_match_device(sun6i_rtc_ccu_match, dev);
346 	if (!match)
347 		return 0;
348 
349 	data = match->data;
350 	have_iosc_calibration = data->have_iosc_calibration;
351 
352 	if (data->have_ext_osc32k) {
353 		const char *fw_name;
354 
355 		/* ext-osc32k was the only input clock in the old binding. */
356 		fw_name = of_property_read_bool(dev->of_node, "clock-names")
357 			? "ext-osc32k" : NULL;
358 		ext_osc32k_clk = devm_clk_get_optional(dev, fw_name);
359 		if (IS_ERR(ext_osc32k_clk))
360 			return PTR_ERR(ext_osc32k_clk);
361 	}
362 
363 	if (ext_osc32k_clk) {
364 		/* Link ext-osc32k-gate to its parent. */
365 		*ext_osc32k = __clk_get_hw(ext_osc32k_clk);
366 	} else {
367 		/* ext-osc32k-gate is an orphan, so do not register it. */
368 		sun6i_rtc_ccu_hw_clks.hws[CLK_EXT_OSC32K_GATE] = NULL;
369 		osc32k_init_data.num_parents = 1;
370 	}
371 
372 	if (data->rtc_32k_single_parent)
373 		rtc_32k_init_data.num_parents = 1;
374 
375 	osc32k_fanout_init_data.parent_data = data->osc32k_fanout_parents;
376 	osc32k_fanout_init_data.num_parents = data->osc32k_fanout_nparents;
377 
378 	return devm_sunxi_ccu_probe(dev, reg, &sun6i_rtc_ccu_desc);
379 }
380 
381 MODULE_IMPORT_NS(SUNXI_CCU);
382 MODULE_LICENSE("GPL");
383