openwrtv3/target/linux/ipq806x/patches/0165-clk-qcom-Add-support-for-muxes-dividers-and-mux-divi.patch
John Crispin 3c1f6e358d ipq806x: Add support for IPQ806x chip family
Patches are generated using the "format-patch" command from the
following location:
*https://www.codeaurora.org/cgit/quic/kernel/galak-msm/log/?h=apq_ipq_base
*rev=0771849495b4128cac2faf7d49c85c729fc48b20
Patches numbered 76/77/102/103 have already been integrated in 3.14.12,
so they're not in this list.

All these patches are either integrated are pending integration into
kernel.org, therefore these patches should go away once the kernel
gets upgraded to 3.16.

Support is currently limited to AP148 board but can be extended to other
platforms in the future.

These changes do not cover ethernet connectivity.

Signed-off-by: Mathieu Olivari <mathieu@codeaurora.org>

SVN-Revision: 42334
2014-08-30 09:32:58 +00:00

663 lines
17 KiB
Diff

From 151d7e91baaa4016ba687b80e8f7ccead62d6c72 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <sboyd@codeaurora.org>
Date: Tue, 25 Mar 2014 13:37:55 -0700
Subject: [PATCH 165/182] clk: qcom: Add support for muxes, dividers, and mux
dividers
The Krait CPU clocks are made up of muxes and dividers with a
handful of sources. Add a set of clk_ops that allow us to
configure these clocks so we can support CPU frequency scaling on
Krait CPUs.
Based on code originally written by Saravana Kannan.
Cc: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/clk-generic.c | 405 +++++++++++++++++++++++++++++++++++
include/linux/clk/msm-clk-generic.h | 208 ++++++++++++++++++
3 files changed, 614 insertions(+)
create mode 100644 drivers/clk/qcom/clk-generic.c
create mode 100644 include/linux/clk/msm-clk-generic.h
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index df2a1b3..2cc6039 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-y += clk-generic.o
clk-qcom-y += reset.o
obj-$(CONFIG_IPQ_GCC_806X) += gcc-ipq806x.o
diff --git a/drivers/clk/qcom/clk-generic.c b/drivers/clk/qcom/clk-generic.c
new file mode 100644
index 0000000..a0d778b
--- /dev/null
+++ b/drivers/clk/qcom/clk-generic.c
@@ -0,0 +1,405 @@
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/bug.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/msm-clk-generic.h>
+
+
+/* ==================== Mux clock ==================== */
+
+static int mux_set_parent(struct clk_hw *hw, u8 sel)
+{
+ struct mux_clk *mux = to_mux_clk(hw);
+
+ if (mux->parent_map)
+ sel = mux->parent_map[sel];
+
+ return mux->ops->set_mux_sel(mux, sel);
+}
+
+static u8 mux_get_parent(struct clk_hw *hw)
+{
+ struct mux_clk *mux = to_mux_clk(hw);
+ int num_parents = __clk_get_num_parents(hw->clk);
+ int i;
+ u8 sel;
+
+ sel = mux->ops->get_mux_sel(mux);
+ if (mux->parent_map) {
+ for (i = 0; i < num_parents; i++)
+ if (sel == mux->parent_map[i])
+ return i;
+ WARN(1, "Can't find parent\n");
+ return -EINVAL;
+ }
+
+ return sel;
+}
+
+static int mux_enable(struct clk_hw *hw)
+{
+ struct mux_clk *mux = to_mux_clk(hw);
+ if (mux->ops->enable)
+ return mux->ops->enable(mux);
+ return 0;
+}
+
+static void mux_disable(struct clk_hw *hw)
+{
+ struct mux_clk *mux = to_mux_clk(hw);
+ if (mux->ops->disable)
+ return mux->ops->disable(mux);
+}
+
+static struct clk *mux_get_safe_parent(struct clk_hw *hw)
+{
+ int i;
+ struct mux_clk *mux = to_mux_clk(hw);
+ int num_parents = __clk_get_num_parents(hw->clk);
+
+ if (!mux->has_safe_parent)
+ return NULL;
+
+ i = mux->safe_sel;
+ if (mux->parent_map)
+ 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);
+}
+
+const struct clk_ops clk_ops_gen_mux = {
+ .enable = mux_enable,
+ .disable = mux_disable,
+ .set_parent = mux_set_parent,
+ .get_parent = mux_get_parent,
+ .determine_rate = __clk_mux_determine_rate,
+ .get_safe_parent = mux_get_safe_parent,
+};
+EXPORT_SYMBOL_GPL(clk_ops_gen_mux);
+
+/* ==================== Divider clock ==================== */
+
+static long __div_round_rate(struct div_data *data, unsigned long rate,
+ struct clk *parent, unsigned int *best_div, unsigned long *best_prate,
+ bool set_parent)
+{
+ unsigned int div, min_div, max_div, _best_div = 1;
+ unsigned long prate, _best_prate = 0, rrate = 0, req_prate, actual_rate;
+ unsigned int numer;
+
+ rate = max(rate, 1UL);
+
+ min_div = max(data->min_div, 1U);
+ max_div = min(data->max_div, (unsigned int) (ULONG_MAX / rate));
+
+ /*
+ * div values are doubled for half dividers.
+ * Adjust for that by picking a numer of 2.
+ */
+ numer = data->is_half_divider ? 2 : 1;
+
+ if (!set_parent) {
+ prate = *best_prate * numer;
+ div = DIV_ROUND_UP(prate, rate);
+ div = clamp(1U, div, max_div);
+ if (best_div)
+ *best_div = div;
+ return mult_frac(*best_prate, numer, div);
+ }
+
+ for (div = min_div; div <= max_div; div++) {
+ req_prate = mult_frac(rate, div, numer);
+ prate = __clk_round_rate(parent, req_prate);
+ if (IS_ERR_VALUE(prate))
+ break;
+
+ actual_rate = mult_frac(prate, numer, div);
+ if (is_better_rate(rate, rrate, actual_rate)) {
+ rrate = actual_rate;
+ _best_div = div;
+ _best_prate = prate;
+ }
+
+ /*
+ * Trying higher dividers is only going to ask the parent for
+ * a higher rate. If it can't even output a rate higher than
+ * the one we request for this divider, the parent is not
+ * going to be able to output an even higher rate required
+ * for a higher divider. So, stop trying higher dividers.
+ */
+ if (actual_rate < rate)
+ break;
+
+ if (rrate <= rate)
+ break;
+ }
+
+ if (!rrate)
+ return -EINVAL;
+ if (best_div)
+ *best_div = _best_div;
+ if (best_prate)
+ *best_prate = _best_prate;
+
+ return rrate;
+}
+
+static long div_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct div_clk *d = to_div_clk(hw);
+ bool set_parent = __clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT;
+
+ return __div_round_rate(&d->data, rate, __clk_get_parent(hw->clk),
+ NULL, parent_rate, set_parent);
+}
+
+static int div_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long
+ parent_rate)
+{
+ struct div_clk *d = to_div_clk(hw);
+ int div, rc = 0;
+ struct div_data *data = &d->data;
+
+ div = parent_rate / rate;
+ if (div != data->div)
+ rc = d->ops->set_div(d, div);
+ data->div = div;
+
+ return rc;
+}
+
+static int div_enable(struct clk_hw *hw)
+{
+ struct div_clk *d = to_div_clk(hw);
+ if (d->ops && d->ops->enable)
+ return d->ops->enable(d);
+ return 0;
+}
+
+static void div_disable(struct clk_hw *hw)
+{
+ struct div_clk *d = to_div_clk(hw);
+ if (d->ops && d->ops->disable)
+ return d->ops->disable(d);
+}
+
+static unsigned long div_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+ struct div_clk *d = to_div_clk(hw);
+ unsigned int div = d->data.div;
+
+ if (d->ops && d->ops->get_div)
+ div = max(d->ops->get_div(d), 1);
+ div = max(div, 1U);
+
+ if (!d->ops || !d->ops->set_div)
+ d->data.min_div = d->data.max_div = div;
+ d->data.div = div;
+
+ return prate / div;
+}
+
+const struct clk_ops clk_ops_div = {
+ .enable = div_enable,
+ .disable = div_disable,
+ .round_rate = div_round_rate,
+ .set_rate = div_set_rate,
+ .recalc_rate = div_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(clk_ops_div);
+
+/* ==================== Mux_div clock ==================== */
+
+static int mux_div_clk_enable(struct clk_hw *hw)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+
+ if (md->ops->enable)
+ return md->ops->enable(md);
+ return 0;
+}
+
+static void mux_div_clk_disable(struct clk_hw *hw)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+
+ if (md->ops->disable)
+ return md->ops->disable(md);
+}
+
+static long __mux_div_round_rate(struct clk_hw *hw, unsigned long rate,
+ struct clk **best_parent, int *best_div, unsigned long *best_prate)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ unsigned int i;
+ unsigned long rrate, best = 0, _best_div = 0, _best_prate = 0;
+ struct clk *_best_parent = 0;
+ int num_parents = __clk_get_num_parents(hw->clk);
+ bool set_parent = __clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT;
+
+ for (i = 0; i < num_parents; i++) {
+ int div;
+ unsigned long prate;
+ struct clk *p = clk_get_parent_by_index(hw->clk, i);
+
+ rrate = __div_round_rate(&md->data, rate, p, &div, &prate,
+ set_parent);
+
+ if (is_better_rate(rate, best, rrate)) {
+ best = rrate;
+ _best_div = div;
+ _best_prate = prate;
+ _best_parent = p;
+ }
+
+ if (rate <= rrate)
+ break;
+ }
+
+ if (best_div)
+ *best_div = _best_div;
+ if (best_prate)
+ *best_prate = _best_prate;
+ if (best_parent)
+ *best_parent = _best_parent;
+
+ if (best)
+ return best;
+ return -EINVAL;
+}
+
+static long mux_div_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ return __mux_div_round_rate(hw, rate, NULL, NULL, parent_rate);
+}
+
+/* requires enable lock to be held */
+static int __set_src_div(struct mux_div_clk *md, u8 src_sel, u32 div)
+{
+ int rc;
+
+ rc = md->ops->set_src_div(md, src_sel, div);
+ if (!rc) {
+ md->data.div = div;
+ md->src_sel = src_sel;
+ }
+
+ return rc;
+}
+
+/* Must be called after handoff to ensure parent clock rates are initialized */
+static int safe_parent_init_once(struct clk_hw *hw)
+{
+ unsigned long rrate;
+ u32 best_div;
+ struct clk *best_parent;
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+
+ if (IS_ERR(md->safe_parent))
+ return -EINVAL;
+ if (!md->safe_freq || md->safe_parent)
+ return 0;
+
+ rrate = __mux_div_round_rate(hw, md->safe_freq, &best_parent,
+ &best_div, NULL);
+
+ if (rrate == md->safe_freq) {
+ md->safe_div = best_div;
+ md->safe_parent = best_parent;
+ } else {
+ md->safe_parent = ERR_PTR(-EINVAL);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int
+__mux_div_clk_set_rate_and_parent(struct clk_hw *hw, u8 index, u32 div)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ int rc;
+
+ rc = safe_parent_init_once(hw);
+ if (rc)
+ return rc;
+
+ return __set_src_div(md, index, div);
+}
+
+static int mux_div_clk_set_rate_and_parent(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate, u8 index)
+{
+ return __mux_div_clk_set_rate_and_parent(hw, index, parent_rate / rate);
+}
+
+static int mux_div_clk_set_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ return __mux_div_clk_set_rate_and_parent(hw, md->src_sel,
+ parent_rate / rate);
+}
+
+static int mux_div_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ return __mux_div_clk_set_rate_and_parent(hw, md->parent_map[index],
+ md->data.div);
+}
+
+static u8 mux_div_clk_get_parent(struct clk_hw *hw)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ int num_parents = __clk_get_num_parents(hw->clk);
+ u32 i, div, sel;
+
+ md->ops->get_src_div(md, &sel, &div);
+ md->src_sel = sel;
+
+ for (i = 0; i < num_parents; i++)
+ if (sel == md->parent_map[i])
+ return i;
+ WARN(1, "Can't find parent\n");
+ return -EINVAL;
+}
+
+static unsigned long
+mux_div_clk_recalc_rate(struct clk_hw *hw, unsigned long prate)
+{
+ struct mux_div_clk *md = to_mux_div_clk(hw);
+ u32 div, sel;
+
+ md->ops->get_src_div(md, &sel, &div);
+
+ return prate / div;
+}
+
+const struct clk_ops clk_ops_mux_div_clk = {
+ .enable = mux_div_clk_enable,
+ .disable = mux_div_clk_disable,
+ .set_rate_and_parent = mux_div_clk_set_rate_and_parent,
+ .set_rate = mux_div_clk_set_rate,
+ .set_parent = mux_div_clk_set_parent,
+ .round_rate = mux_div_clk_round_rate,
+ .get_parent = mux_div_clk_get_parent,
+ .recalc_rate = mux_div_clk_recalc_rate,
+};
+EXPORT_SYMBOL_GPL(clk_ops_mux_div_clk);
diff --git a/include/linux/clk/msm-clk-generic.h b/include/linux/clk/msm-clk-generic.h
new file mode 100644
index 0000000..cee3863
--- /dev/null
+++ b/include/linux/clk/msm-clk-generic.h
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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_GENERIC_H__
+#define __QCOM_CLK_GENERIC_H__
+
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+
+static inline bool is_better_rate(unsigned long req, unsigned long best,
+ unsigned long new)
+{
+ if (IS_ERR_VALUE(new))
+ return false;
+
+ return (req <= new && new < best) || (best < req && best < new);
+}
+
+/* ==================== Mux clock ==================== */
+
+struct mux_clk;
+
+struct clk_mux_ops {
+ int (*set_mux_sel)(struct mux_clk *clk, int sel);
+ int (*get_mux_sel)(struct mux_clk *clk);
+
+ /* Optional */
+ bool (*is_enabled)(struct mux_clk *clk);
+ int (*enable)(struct mux_clk *clk);
+ void (*disable)(struct mux_clk *clk);
+};
+
+struct mux_clk {
+ /* Parents in decreasing order of preference for obtaining rates. */
+ u8 *parent_map;
+ bool has_safe_parent;
+ u8 safe_sel;
+ const struct clk_mux_ops *ops;
+
+ /* Fields not used by helper function. */
+ void __iomem *base;
+ u32 offset;
+ u32 en_offset;
+ int en_reg;
+ u32 mask;
+ u32 shift;
+ u32 en_mask;
+ void *priv;
+
+ struct clk_hw hw;
+};
+
+static inline struct mux_clk *to_mux_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct mux_clk, hw);
+}
+
+extern const struct clk_ops clk_ops_gen_mux;
+
+/* ==================== Divider clock ==================== */
+
+struct div_clk;
+
+struct clk_div_ops {
+ int (*set_div)(struct div_clk *clk, int div);
+ int (*get_div)(struct div_clk *clk);
+ bool (*is_enabled)(struct div_clk *clk);
+ int (*enable)(struct div_clk *clk);
+ void (*disable)(struct div_clk *clk);
+};
+
+struct div_data {
+ unsigned int div;
+ unsigned int min_div;
+ unsigned int max_div;
+ /*
+ * Indicate whether this divider clock supports half-interger divider.
+ * If it is, all the min_div and max_div have been doubled. It means
+ * they are 2*N.
+ */
+ bool is_half_divider;
+};
+
+struct div_clk {
+ struct div_data data;
+
+ /* Optional */
+ const struct clk_div_ops *ops;
+
+ /* Fields not used by helper function. */
+ void __iomem *base;
+ u32 offset;
+ u32 mask;
+ u32 shift;
+ u32 en_mask;
+ void *priv;
+ struct clk_hw hw;
+};
+
+static inline struct div_clk *to_div_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct div_clk, hw);
+}
+
+extern const struct clk_ops clk_ops_div;
+
+#define DEFINE_FIXED_DIV_CLK(clk_name, _div, _parent) \
+static struct div_clk clk_name = { \
+ .data = { \
+ .max_div = _div, \
+ .min_div = _div, \
+ .div = _div, \
+ }, \
+ .hw.init = &(struct clk_init_data){ \
+ .parent_names = (const char *[]){ _parent }, \
+ .num_parents = 1, \
+ .name = #clk_name, \
+ .ops = &clk_ops_div, \
+ .flags = CLK_SET_RATE_PARENT, \
+ } \
+}
+
+/* ==================== Mux Div clock ==================== */
+
+struct mux_div_clk;
+
+/*
+ * struct mux_div_ops
+ * the enable and disable ops are optional.
+ */
+
+struct mux_div_ops {
+ int (*set_src_div)(struct mux_div_clk *, u32 src_sel, u32 div);
+ void (*get_src_div)(struct mux_div_clk *, u32 *src_sel, u32 *div);
+ int (*enable)(struct mux_div_clk *);
+ void (*disable)(struct mux_div_clk *);
+ bool (*is_enabled)(struct mux_div_clk *);
+};
+
+/*
+ * struct mux_div_clk - combined mux/divider clock
+ * @priv
+ parameters needed by ops
+ * @safe_freq
+ when switching rates from A to B, the mux div clock will
+ instead switch from A -> safe_freq -> B. This allows the
+ mux_div clock to change rates while enabled, even if this
+ behavior is not supported by the parent clocks.
+
+ If changing the rate of parent A also causes the rate of
+ parent B to change, then safe_freq must be defined.
+
+ safe_freq is expected to have a source clock which is always
+ on and runs at only one rate.
+ * @parents
+ list of parents and mux indicies
+ * @ops
+ function pointers for hw specific operations
+ * @src_sel
+ the mux index which will be used if the clock is enabled.
+ */
+
+struct mux_div_clk {
+ /* Required parameters */
+ const struct mux_div_ops *ops;
+ struct div_data data;
+ u8 *parent_map;
+
+ struct clk_hw hw;
+
+ /* Internal */
+ u32 src_sel;
+
+ /* Optional parameters */
+ void *priv;
+ void __iomem *base;
+ u32 div_mask;
+ u32 div_offset;
+ u32 div_shift;
+ u32 src_mask;
+ u32 src_offset;
+ u32 src_shift;
+ u32 en_mask;
+ u32 en_offset;
+
+ u32 safe_div;
+ struct clk *safe_parent;
+ unsigned long safe_freq;
+};
+
+static inline struct mux_div_clk *to_mux_div_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct mux_div_clk, hw);
+}
+
+extern const struct clk_ops clk_ops_mux_div_clk;
+
+#endif
--
1.7.10.4