summaryrefslogtreecommitdiff
path: root/target/linux/ipq806x/patches-4.1/137-clk-qcom-Add-support-for-High-Frequency-PLLs-HFPLLs.patch
blob: 6fad6e8a0cc92e4d39a8113fdef8e8a6d45c60bd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: [v3,05/13] clk: qcom: Add support for High-Frequency PLLs (HFPLLs)
From: Stephen Boyd <sboyd@codeaurora.org>
X-Patchwork-Id: 6063261
Message-Id: <1426920332-9340-6-git-send-email-sboyd@codeaurora.org>
To: Mike Turquette <mturquette@linaro.org>, Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	Viresh Kumar <viresh.kumar@linaro.org>
Date: Fri, 20 Mar 2015 23:45:24 -0700

HFPLLs are the main frequency source for Krait CPU clocks. Add
support for changing the rate of these PLLs.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

---
I'd really like to get rid of __clk_hfpll_init_once() if possible...

 drivers/clk/qcom/Makefile    |   1 +
 drivers/clk/qcom/clk-hfpll.c | 253 +++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-hfpll.h |  54 +++++++++
 3 files changed, 308 insertions(+)
 create mode 100644 drivers/clk/qcom/clk-hfpll.c
 create mode 100644 drivers/clk/qcom/clk-hfpll.h

--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -8,6 +8,7 @@ clk-qcom-y += clk-rcg2.o
 clk-qcom-y += clk-branch.o
 clk-qcom-y += clk-regmap-divider.o
 clk-qcom-y += clk-regmap-mux.o
+clk-qcom-y += clk-hfpll.o
 clk-qcom-y += reset.o
 
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o
--- /dev/null
+++ b/drivers/clk/qcom/clk-hfpll.c
@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+
+#include "clk-regmap.h"
+#include "clk-hfpll.h"
+
+#define PLL_OUTCTRL	BIT(0)
+#define PLL_BYPASSNL	BIT(1)
+#define PLL_RESET_N	BIT(2)
+
+/* Initialize a HFPLL at a given rate and enable it. */
+static void __clk_hfpll_init_once(struct clk_hw *hw)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+
+	if (likely(h->init_done))
+		return;
+
+	/* Configure PLL parameters for integer mode. */
+	if (hd->config_val)
+		regmap_write(regmap, hd->config_reg, hd->config_val);
+	regmap_write(regmap, hd->m_reg, 0);
+	regmap_write(regmap, hd->n_reg, 1);
+
+	if (hd->user_reg) {
+		u32 regval = hd->user_val;
+		unsigned long rate;
+
+		rate = __clk_get_rate(hw->clk);
+
+		/* Pick the right VCO. */
+		if (hd->user_vco_mask && rate > hd->low_vco_max_rate)
+			regval |= hd->user_vco_mask;
+		regmap_write(regmap, hd->user_reg, regval);
+	}
+
+	if (hd->droop_reg)
+		regmap_write(regmap, hd->droop_reg, hd->droop_val);
+
+	h->init_done = true;
+}
+
+static void __clk_hfpll_enable(struct clk_hw *hw)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	u32 val;
+
+	__clk_hfpll_init_once(hw);
+
+	/* Disable PLL bypass mode. */
+	regmap_update_bits(regmap, hd->mode_reg, PLL_BYPASSNL, PLL_BYPASSNL);
+
+	/*
+	 * H/W requires a 5us delay between disabling the bypass and
+	 * de-asserting the reset. Delay 10us just to be safe.
+	 */
+	udelay(10);
+
+	/* De-assert active-low PLL reset. */
+	regmap_update_bits(regmap, hd->mode_reg, PLL_RESET_N, PLL_RESET_N);
+
+	/* Wait for PLL to lock. */
+	if (hd->status_reg) {
+		do {
+			regmap_read(regmap, hd->status_reg, &val);
+		} while (!(val & BIT(hd->lock_bit)));
+	} else {
+		udelay(60);
+	}
+
+	/* Enable PLL output. */
+	regmap_update_bits(regmap, hd->mode_reg, PLL_OUTCTRL, PLL_OUTCTRL);
+}
+
+/* Enable an already-configured HFPLL. */
+static int clk_hfpll_enable(struct clk_hw *hw)
+{
+	unsigned long flags;
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	u32 mode;
+
+	spin_lock_irqsave(&h->lock, flags);
+	regmap_read(regmap, hd->mode_reg, &mode);
+	if (!(mode & (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)))
+		__clk_hfpll_enable(hw);
+	spin_unlock_irqrestore(&h->lock, flags);
+
+	return 0;
+}
+
+static void __clk_hfpll_disable(struct clk_hfpll *h)
+{
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+
+	/*
+	 * Disable the PLL output, disable test mode, enable the bypass mode,
+	 * and assert the reset.
+	 */
+	regmap_update_bits(regmap, hd->mode_reg,
+			PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL, 0);
+}
+
+static void clk_hfpll_disable(struct clk_hw *hw)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	unsigned long flags;
+
+	spin_lock_irqsave(&h->lock, flags);
+	__clk_hfpll_disable(h);
+	spin_unlock_irqrestore(&h->lock, flags);
+}
+
+static long clk_hfpll_round_rate(struct clk_hw *hw, unsigned long rate,
+				 unsigned long *parent_rate)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	unsigned long rrate;
+
+	rate = clamp(rate, hd->min_rate, hd->max_rate);
+
+	rrate = DIV_ROUND_UP(rate, *parent_rate) * *parent_rate;
+	if (rrate > hd->max_rate)
+		rrate -= *parent_rate;
+
+	return rrate;
+}
+
+/*
+ * For optimization reasons, assumes no downstream clocks are actively using
+ * it.
+ */
+static int clk_hfpll_set_rate(struct clk_hw *hw, unsigned long rate,
+			      unsigned long parent_rate)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	unsigned long flags;
+	u32 l_val, val;
+	bool enabled;
+
+	l_val = rate / parent_rate;
+
+	spin_lock_irqsave(&h->lock, flags);
+
+	enabled = __clk_is_enabled(hw->clk);
+	if (enabled)
+		__clk_hfpll_disable(h);
+
+	/* Pick the right VCO. */
+	if (hd->user_reg && hd->user_vco_mask) {
+		regmap_read(regmap, hd->user_reg, &val);
+		if (rate <= hd->low_vco_max_rate)
+			val &= ~hd->user_vco_mask;
+		else
+			val |= hd->user_vco_mask;
+		regmap_write(regmap, hd->user_reg, val);
+	}
+
+	regmap_write(regmap, hd->l_reg, l_val);
+
+	if (enabled)
+		__clk_hfpll_enable(hw);
+
+	spin_unlock_irqrestore(&h->lock, flags);
+
+	return 0;
+}
+
+static unsigned long clk_hfpll_recalc_rate(struct clk_hw *hw,
+					   unsigned long parent_rate)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	u32 l_val;
+
+	regmap_read(regmap, hd->l_reg, &l_val);
+
+	return l_val * parent_rate;
+}
+
+static void clk_hfpll_init(struct clk_hw *hw)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	u32 mode, status;
+
+	regmap_read(regmap, hd->mode_reg, &mode);
+	if (mode != (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)) {
+		__clk_hfpll_init_once(hw);
+		return;
+	}
+
+	if (hd->status_reg) {
+		regmap_read(regmap, hd->status_reg, &status);
+		if (!(status & BIT(hd->lock_bit))) {
+			WARN(1, "HFPLL %s is ON, but not locked!\n",
+					__clk_get_name(hw->clk));
+			clk_hfpll_disable(hw);
+			__clk_hfpll_init_once(hw);
+		}
+	}
+}
+
+static int hfpll_is_enabled(struct clk_hw *hw)
+{
+	struct clk_hfpll *h = to_clk_hfpll(hw);
+	struct hfpll_data const *hd = h->d;
+	struct regmap *regmap = h->clkr.regmap;
+	u32 mode;
+
+	regmap_read(regmap, hd->mode_reg, &mode);
+	mode &= 0x7;
+	return mode == (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL);
+}
+
+const struct clk_ops clk_ops_hfpll = {
+	.enable = clk_hfpll_enable,
+	.disable = clk_hfpll_disable,
+	.is_enabled = hfpll_is_enabled,
+	.round_rate = clk_hfpll_round_rate,
+	.set_rate = clk_hfpll_set_rate,
+	.recalc_rate = clk_hfpll_recalc_rate,
+	.init = clk_hfpll_init,
+};
+EXPORT_SYMBOL_GPL(clk_ops_hfpll);
--- /dev/null
+++ b/drivers/clk/qcom/clk-hfpll.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __QCOM_CLK_HFPLL_H__
+#define __QCOM_CLK_HFPLL_H__
+
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+#include "clk-regmap.h"
+
+struct hfpll_data {
+	u32 mode_reg;
+	u32 l_reg;
+	u32 m_reg;
+	u32 n_reg;
+	u32 user_reg;
+	u32 droop_reg;
+	u32 config_reg;
+	u32 status_reg;
+	u8  lock_bit;
+
+	u32 droop_val;
+	u32 config_val;
+	u32 user_val;
+	u32 user_vco_mask;
+	unsigned long low_vco_max_rate;
+
+	unsigned long min_rate;
+	unsigned long max_rate;
+};
+
+struct clk_hfpll {
+	struct hfpll_data const *d;
+	int init_done;
+
+	struct clk_regmap clkr;
+	spinlock_t lock;
+};
+
+#define to_clk_hfpll(_hw) \
+	container_of(to_clk_regmap(_hw), struct clk_hfpll, clkr)
+
+extern const struct clk_ops clk_ops_hfpll;
+
+#endif