aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/ipq806x/patches-4.4/140-clk-qcom-Add-support-for-Krait-clocks.patch
blob: ecf1ef589cdcd32b399071c820a7236992447bae (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
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Subject: [v3,09/13] clk: qcom: Add support for Krait clocks
From: Stephen Boyd <sboyd@codeaurora.org>
X-Patchwork-Id: 6063251
Message-Id: <1426920332-9340-10-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 23:45:28 -0700

The Krait clocks are made up of a series of muxes and a divider
that choose between a fixed rate clock and dedicated HFPLLs for
each CPU. Instead of using mmio accesses to remux parents, the
Krait implementation exposes the remux control via cp15
registers. Support these clocks.

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

---
drivers/clk/qcom/Kconfig     |   4 ++
 drivers/clk/qcom/Makefile    |   1 +
 drivers/clk/qcom/clk-krait.c | 166 +++++++++++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-krait.h |  49 +++++++++++++
 4 files changed, 220 insertions(+)
 create mode 100644 drivers/clk/qcom/clk-krait.c
 create mode 100644 drivers/clk/qcom/clk-krait.h

--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -114,3 +114,7 @@ config QCOM_HFPLL
 	  Support for the high-frequency PLLs present on Qualcomm devices.
 	  Say Y if you want to support CPU frequency scaling on devices
 	  such as MSM8974, APQ8084, etc.
+
+config KRAIT_CLOCKS
+	bool
+	select KRAIT_L2_ACCESSORS
--- 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-$(CONFIG_KRAIT_CLOCKS) += clk-krait.o
 clk-qcom-y += clk-hfpll.o
 clk-qcom-y += reset.o
 clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o
--- /dev/null
+++ b/drivers/clk/qcom/clk-krait.c
@@ -0,0 +1,166 @@
+/*
+ * 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/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+
+#include <asm/krait-l2-accessors.h>
+
+#include "clk-krait.h"
+
+/* Secondary and primary muxes share the same cp15 register */
+static DEFINE_SPINLOCK(krait_clock_reg_lock);
+
+#define LPL_SHIFT	8
+static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
+{
+	unsigned long flags;
+	u32 regval;
+
+	spin_lock_irqsave(&krait_clock_reg_lock, flags);
+	regval = krait_get_l2_indirect_reg(mux->offset);
+	regval &= ~(mux->mask << mux->shift);
+	regval |= (sel & mux->mask) << mux->shift;
+	if (mux->lpl) {
+		regval &= ~(mux->mask << (mux->shift + LPL_SHIFT));
+		regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
+	}
+	krait_set_l2_indirect_reg(mux->offset, regval);
+	spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
+
+	/* Wait for switch to complete. */
+	mb();
+	udelay(1);
+}
+
+static int krait_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct krait_mux_clk *mux = to_krait_mux_clk(hw);
+	u32 sel;
+
+	sel = clk_mux_reindex(index, mux->parent_map, 0);
+	mux->en_mask = sel;
+	/* Don't touch mux if CPU is off as it won't work */
+	if (__clk_is_enabled(hw->clk))
+		__krait_mux_set_sel(mux, sel);
+	return 0;
+}
+
+static u8 krait_mux_get_parent(struct clk_hw *hw)
+{
+	struct krait_mux_clk *mux = to_krait_mux_clk(hw);
+	u32 sel;
+
+	sel = krait_get_l2_indirect_reg(mux->offset);
+	sel >>= mux->shift;
+	sel &= mux->mask;
+	mux->en_mask = sel;
+
+	return clk_mux_get_parent(hw, sel, mux->parent_map, 0);
+}
+
+static struct clk_hw *krait_mux_get_safe_parent(struct clk_hw *hw)
+{
+	int i;
+	struct krait_mux_clk *mux = to_krait_mux_clk(hw);
+	int num_parents = clk_hw_get_num_parents(hw->clk);
+
+	i = mux->safe_sel;
+	for (i = 0; i < num_parents; i++)
+		if (mux->safe_sel == mux->parent_map[i])
+			break;
+
+	return __clk_get_hw(clk_hw_get_parent_by_index(hw->clk, i));
+}
+
+static int krait_mux_enable(struct clk_hw *hw)
+{
+	struct krait_mux_clk *mux = to_krait_mux_clk(hw);
+
+	__krait_mux_set_sel(mux, mux->en_mask);
+
+	return 0;
+}
+
+static void krait_mux_disable(struct clk_hw *hw)
+{
+	struct krait_mux_clk *mux = to_krait_mux_clk(hw);
+
+	__krait_mux_set_sel(mux, mux->safe_sel);
+}
+
+const struct clk_ops krait_mux_clk_ops = {
+	.enable = krait_mux_enable,
+	.disable = krait_mux_disable,
+	.set_parent = krait_mux_set_parent,
+	.get_parent = krait_mux_get_parent,
+	.determine_rate = __clk_mux_determine_rate_closest,
+	.get_safe_parent = krait_mux_get_safe_parent,
+};
+EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
+
+/* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */
+static long krait_div2_round_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long *parent_rate)
+{
+	*parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw->clk), rate * 2);
+	return DIV_ROUND_UP(*parent_rate, 2);
+}
+
+static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate,
+			unsigned long parent_rate)
+{
+	struct krait_div2_clk *d = to_krait_div2_clk(hw);
+	unsigned long flags;
+	u32 val;
+	u32 mask = BIT(d->width) - 1;
+
+	if (d->lpl)
+		mask = mask << (d->shift + LPL_SHIFT) | mask << d->shift;
+
+	spin_lock_irqsave(&krait_clock_reg_lock, flags);
+	val = krait_get_l2_indirect_reg(d->offset);
+	val &= ~mask;
+	krait_set_l2_indirect_reg(d->offset, val);
+	spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
+
+	return 0;
+}
+
+static unsigned long
+krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
+{
+	struct krait_div2_clk *d = to_krait_div2_clk(hw);
+	u32 mask = BIT(d->width) - 1;
+	u32 div;
+
+	div = krait_get_l2_indirect_reg(d->offset);
+	div >>= d->shift;
+	div &= mask;
+	div = (div + 1) * 2;
+
+	return DIV_ROUND_UP(parent_rate, div);
+}
+
+const struct clk_ops krait_div2_clk_ops = {
+	.round_rate = krait_div2_round_rate,
+	.set_rate = krait_div2_set_rate,
+	.recalc_rate = krait_div2_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(krait_div2_clk_ops);
--- /dev/null
+++ b/drivers/clk/qcom/clk-krait.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2013, 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_KRAIT_H
+#define __QCOM_CLK_KRAIT_H
+
+#include <linux/clk-provider.h>
+
+struct krait_mux_clk {
+	unsigned int	*parent_map;
+	bool		has_safe_parent;
+	u8		safe_sel;
+	u32		offset;
+	u32		mask;
+	u32		shift;
+	u32		en_mask;
+	bool		lpl;
+
+	struct clk_hw	hw;
+};
+
+#define to_krait_mux_clk(_hw) container_of(_hw, struct krait_mux_clk, hw)
+
+extern const struct clk_ops krait_mux_clk_ops;
+
+struct krait_div2_clk {
+	u32		offset;
+	u8		width;
+	u32		shift;
+	bool		lpl;
+
+	struct clk_hw	hw;
+};
+
+#define to_krait_div2_clk(_hw) container_of(_hw, struct krait_div2_clk, hw)
+
+extern const struct clk_ops krait_div2_clk_ops;
+
+#endif