diff options
| -rw-r--r-- | drivers/clk/clk.c | 20 | ||||
| -rw-r--r-- | drivers/clk/qcom/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/qcom/clk-voter.c | 133 | ||||
| -rw-r--r-- | drivers/clk/qcom/clk-voter.h | 50 | ||||
| -rw-r--r-- | include/linux/clk-provider.h | 3 |
5 files changed, 207 insertions, 1 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index ed763c7e98fc..1c625764133d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -547,6 +547,26 @@ void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, EXPORT_SYMBOL_GPL(clk_hw_set_rate_range); /* + * Aggregate the rate of all child nodes which are enabled and exclude the + * child node which requests for clk_aggregate_rate. + */ +unsigned long clk_aggregate_rate(struct clk_hw *hw, + const struct clk_core *parent) +{ + struct clk_core *child; + unsigned long aggre_rate = 0; + + hlist_for_each_entry(child, &parent->children, child_node) { + if (child->enable_count && + strcmp(child->name, hw->init->name)) + aggre_rate = max(child->rate, aggre_rate); + } + + return aggre_rate; +} +EXPORT_SYMBOL_GPL(clk_aggregate_rate); + +/* * Helper for finding best parent to provide a given frequency. This can be used * directly as a determine_rate callback (e.g. for a mux), or from a more * complex clock that may combine a mux with other operations. diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile index 7ee0294e9dc7..adebefd63e71 100644 --- a/drivers/clk/qcom/Makefile +++ b/drivers/clk/qcom/Makefile @@ -11,7 +11,7 @@ clk-qcom-y += clk-regmap-divider.o clk-qcom-y += clk-regmap-mux.o clk-qcom-$(CONFIG_KRAIT_CLOCKS) += clk-krait.o clk-qcom-y += clk-hfpll.o -clk-qcom-y += reset.o +clk-qcom-y += reset.o clk-voter.o clk-qcom-y += clk-dummy.o clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o gdsc-regulator.o diff --git a/drivers/clk/qcom/clk-voter.c b/drivers/clk/qcom/clk-voter.c new file mode 100644 index 000000000000..d3409b9e6b64 --- /dev/null +++ b/drivers/clk/qcom/clk-voter.c @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2016, 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/clk.h> + +#include "clk-voter.h" + +static int voter_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int ret = 0; + struct clk_voter *v = to_clk_voter(hw); + unsigned long cur_rate, new_rate, other_rate = 0; + + if (v->is_branch) + return ret; + + if (v->enabled) { + struct clk_hw *parent = clk_hw_get_parent(hw); + + /* + * Get the aggregate rate without this clock's vote and update + * if the new rate is different than the current rate. + */ + other_rate = clk_aggregate_rate(hw, parent->core); + + cur_rate = max(other_rate, clk_get_rate(hw->clk)); + new_rate = max(other_rate, rate); + + if (new_rate != cur_rate) { + ret = clk_set_rate(parent->clk, new_rate); + if (ret) + return ret; + } + } + v->rate = rate; + + return ret; +} + +static int voter_clk_prepare(struct clk_hw *hw) +{ + int ret = 0; + unsigned long cur_rate; + struct clk_hw *parent; + struct clk_voter *v = to_clk_voter(hw); + + parent = clk_hw_get_parent(hw); + + if (v->is_branch) { + v->enabled = true; + return ret; + } + + /* + * Increase the rate if this clock is voting for a higher rate + * than the current rate. + */ + cur_rate = clk_aggregate_rate(hw, parent->core); + + if (v->rate > cur_rate) { + ret = clk_set_rate(parent->clk, v->rate); + if (ret) + return ret; + } + v->enabled = true; + + return ret; +} + +static void voter_clk_unprepare(struct clk_hw *hw) +{ + unsigned long cur_rate, new_rate; + struct clk_hw *parent; + struct clk_voter *v = to_clk_voter(hw); + + + parent = clk_hw_get_parent(hw); + + /* + * Decrease the rate if this clock was the only one voting for + * the highest rate. + */ + v->enabled = false; + if (v->is_branch) + return; + + new_rate = clk_aggregate_rate(hw, parent->core); + cur_rate = max(new_rate, v->rate); + + if (new_rate < cur_rate) + clk_set_rate(parent->clk, new_rate); +} + +static int voter_clk_is_enabled(struct clk_hw *hw) +{ + struct clk_voter *v = to_clk_voter(hw); + + return v->enabled; +} + +static long voter_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + return clk_hw_round_rate(clk_hw_get_parent(hw), rate); +} + +static unsigned long voter_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_voter *v = to_clk_voter(hw); + + return v->rate; +} + +struct clk_ops clk_ops_voter = { + .prepare = voter_clk_prepare, + .unprepare = voter_clk_unprepare, + .set_rate = voter_clk_set_rate, + .is_enabled = voter_clk_is_enabled, + .round_rate = voter_clk_round_rate, + .recalc_rate = voter_clk_recalc_rate, +}; diff --git a/drivers/clk/qcom/clk-voter.h b/drivers/clk/qcom/clk-voter.h new file mode 100644 index 000000000000..27092ae7d131 --- /dev/null +++ b/drivers/clk/qcom/clk-voter.h @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2016, 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_VOTER_H__ +#define __QCOM_CLK_VOTER_H__ + +#include <linux/clk-provider.h> +#include <linux/platform_device.h> + +struct clk_voter { + int is_branch; + bool enabled; + struct clk_hw hw; + unsigned long rate; +}; + +extern struct clk_ops clk_ops_voter; + +#define to_clk_voter(_hw) container_of(_hw, struct clk_voter, hw) + +#define __DEFINE_CLK_VOTER(clk_name, _parent_name, _default_rate, _is_branch) \ + struct clk_voter clk_name = { \ + .is_branch = (_is_branch), \ + .rate = _default_rate, \ + .hw.init = &(struct clk_init_data){ \ + .ops = &clk_ops_voter, \ + .name = #clk_name, \ + .parent_names = (const char *[]){ #_parent_name }, \ + .num_parents = 1, \ + }, \ + } + +#define DEFINE_CLK_VOTER(clk_name, _parent_name, _default_rate) \ + __DEFINE_CLK_VOTER(clk_name, _parent_name, _default_rate, 0) + +#define DEFINE_CLK_BRANCH_VOTER(clk_name, _parent_name) \ + __DEFINE_CLK_VOTER(clk_name, _parent_name, 1000, 1) + +#endif diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 23026ba6ff25..0de2d0c780d7 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -669,6 +669,9 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent); void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, unsigned long max_rate); +unsigned long clk_aggregate_rate(struct clk_hw *hw, + const struct clk_core *parent); + static inline void __clk_hw_set_clk(struct clk_hw *dst, struct clk_hw *src) { dst->clk = src->clk; |