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authorStephen Boyd <sboyd@codeaurora.org>2014-09-05 15:47:31 -0700
committerAndrey Konovalov <andrey.konovalov@linaro.org>2015-01-13 17:56:47 +0300
commitc088051c3844a4c2fd54067476d15786ff43f84d (patch)
treeec59e14f31c72acbe9b2c1a73d0d63d0a9fd91c1
parent2540f1911f9379569b13a0acbbb16494a5f9ccf6 (diff)
downloadlinux-c088051c3844a4c2fd54067476d15786ff43f84d.tar.gz
clk: qcom: Add support for Krait clocks
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>
-rw-r--r--drivers/clk/qcom/Kconfig4
-rw-r--r--drivers/clk/qcom/Makefile1
-rw-r--r--drivers/clk/qcom/clk-krait.c166
-rw-r--r--drivers/clk/qcom/clk-krait.h49
4 files changed, 220 insertions, 0 deletions
diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index 3ff19a51a933..2fd07b17e10e 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -78,3 +78,7 @@ 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
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index db39912cffec..c7fda5e9dcc7 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -6,6 +6,7 @@ clk-qcom-y += clk-pll.o
clk-qcom-y += clk-rcg.o
clk-qcom-y += clk-rcg2.o
clk-qcom-y += clk-branch.o
+clk-qcom-$(CONFIG_KRAIT_CLOCKS) += clk-krait.o
clk-qcom-y += clk-hfpll.o
clk-qcom-y += reset.o
diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
new file mode 100644
index 000000000000..615bfbee1b6a
--- /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 *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_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_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_round_rate(__clk_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);
+
+ 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);
diff --git a/drivers/clk/qcom/clk-krait.h b/drivers/clk/qcom/clk-krait.h
new file mode 100644
index 000000000000..5d0063538e5d
--- /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