diff options
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | drivers/clk/clk.c | 272 |
1 files changed, 218 insertions, 54 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index cdc1fa58e4f1..113456030d66 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -42,8 +42,6 @@ static unsigned long clk_core_get_rate(struct clk_core *clk); static int clk_core_get_phase(struct clk_core *clk); static bool clk_core_is_prepared(struct clk_core *clk); static bool clk_core_is_enabled(struct clk_core *clk); -static unsigned long clk_core_round_rate_nolock(struct clk_core *clk, - unsigned long rate); static struct clk_core *clk_core_lookup(const char *name); /*** private data structures ***/ @@ -59,6 +57,7 @@ struct clk_core { u8 num_parents; u8 new_parent_index; unsigned long rate; + unsigned long req_rate; unsigned long new_rate; struct clk_core *new_parent; struct clk_core *new_child; @@ -70,6 +69,7 @@ struct clk_core { struct hlist_head children; struct hlist_node child_node; struct hlist_node debug_node; + struct hlist_head clks; unsigned int notifier_count; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; @@ -81,6 +81,9 @@ struct clk { struct clk_core *core; const char *dev_id; const char *con_id; + unsigned long min_rate; + unsigned long max_rate; + struct hlist_node child_node; }; /*** locking ***/ @@ -783,6 +786,8 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now, static long clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate, + unsigned long min_rate, + unsigned long max_rate, unsigned long *best_parent_rate, struct clk_hw **best_parent_p, unsigned long flags) @@ -795,7 +800,8 @@ clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate, if (core->flags & CLK_SET_RATE_NO_REPARENT) { parent = core->parent; if (core->flags & CLK_SET_RATE_PARENT) - best = clk_core_round_rate_nolock(parent, rate); + best = __clk_determine_rate(parent->hw, rate, + min_rate, max_rate); else if (parent) best = clk_core_get_rate_nolock(parent); else @@ -810,7 +816,9 @@ clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate, if (!parent) continue; if (core->flags & CLK_SET_RATE_PARENT) - parent_rate = clk_core_round_rate_nolock(parent, rate); + parent_rate = __clk_determine_rate(parent->hw, rate, + min_rate, + max_rate); else parent_rate = clk_core_get_rate_nolock(parent); if (mux_is_better_rate(rate, parent_rate, best, flags)) { @@ -834,25 +842,47 @@ struct clk *__clk_lookup(const char *name) return !core ? NULL : core->hw->clk; } +static void clk_core_get_boundaries(struct clk_core *clk, + unsigned long *min_rate, + unsigned long *max_rate) +{ + struct clk *clk_user; + + *min_rate = 0; + *max_rate = ULONG_MAX; + + hlist_for_each_entry(clk_user, &clk->clks, child_node) + *min_rate = max(*min_rate, clk_user->min_rate); + + hlist_for_each_entry(clk_user, &clk->clks, child_node) + *max_rate = min(*max_rate, clk_user->max_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. */ long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long min_rate, + unsigned long max_rate, unsigned long *best_parent_rate, struct clk_hw **best_parent_p) { - return clk_mux_determine_rate_flags(hw, rate, best_parent_rate, + return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate, + best_parent_rate, best_parent_p, 0); } EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate, + unsigned long min_rate, + unsigned long max_rate, unsigned long *best_parent_rate, struct clk_hw **best_parent_p) { - return clk_mux_determine_rate_flags(hw, rate, best_parent_rate, + return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate, + best_parent_rate, best_parent_p, CLK_MUX_ROUND_CLOSEST); } @@ -1068,7 +1098,9 @@ int clk_enable(struct clk *clk) EXPORT_SYMBOL_GPL(clk_enable); static unsigned long clk_core_round_rate_nolock(struct clk_core *clk, - unsigned long rate) + unsigned long rate, + unsigned long min_rate, + unsigned long max_rate) { unsigned long parent_rate = 0; struct clk_core *parent; @@ -1083,17 +1115,41 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *clk, if (clk->ops->determine_rate) { parent_hw = parent ? parent->hw : NULL; - return clk->ops->determine_rate(clk->hw, rate, &parent_rate, - &parent_hw); + return clk->ops->determine_rate(clk->hw, rate, + min_rate, max_rate, + &parent_rate, &parent_hw); } else if (clk->ops->round_rate) return clk->ops->round_rate(clk->hw, rate, &parent_rate); else if (clk->flags & CLK_SET_RATE_PARENT) - return clk_core_round_rate_nolock(clk->parent, rate); + return clk_core_round_rate_nolock(clk->parent, rate, min_rate, + max_rate); else return clk->rate; } /** + * __clk_determine_rate - get the closest rate actually supported by a clock + * @hw: determine the rate of this clock + * @rate: target rate + * @min_rate: returned rate must be greater than this rate + * @max_rate: returned rate must be less than this rate + * + * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate and + * .determine_rate. + */ +unsigned long __clk_determine_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long min_rate, + unsigned long max_rate) +{ + if (!hw) + return 0; + + return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate); +} +EXPORT_SYMBOL_GPL(__clk_determine_rate); + +/** * __clk_round_rate - round the given rate for a clk * @clk: round the rate of this clock * @rate: the rate which is to be rounded @@ -1102,10 +1158,15 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *clk, */ unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) { + unsigned long min_rate; + unsigned long max_rate; + if (!clk) return 0; - return clk_core_round_rate_nolock(clk->core, rate); + clk_core_get_boundaries(clk->core, &min_rate, &max_rate); + + return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate); } EXPORT_SYMBOL_GPL(__clk_round_rate); @@ -1126,7 +1187,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate) return 0; clk_prepare_lock(); - ret = clk_core_round_rate_nolock(clk->core, rate); + ret = __clk_round_rate(clk, rate); clk_prepare_unlock(); return ret; @@ -1517,6 +1578,8 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk, struct clk_hw *parent_hw; unsigned long best_parent_rate = 0; unsigned long new_rate; + unsigned long min_rate; + unsigned long max_rate; int p_index = 0; /* sanity */ @@ -1528,16 +1591,22 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk, if (parent) best_parent_rate = parent->rate; + clk_core_get_boundaries(clk, &min_rate, &max_rate); + /* find the closest rate and parent clk/rate */ if (clk->ops->determine_rate) { parent_hw = parent ? parent->hw : NULL; new_rate = clk->ops->determine_rate(clk->hw, rate, + min_rate, + max_rate, &best_parent_rate, &parent_hw); parent = parent_hw ? parent_hw->core : NULL; } else if (clk->ops->round_rate) { new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); + if (new_rate < min_rate || new_rate > max_rate) + return NULL; } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { /* pass-through clock without adjustable parent */ clk->new_rate = clk->rate; @@ -1675,6 +1744,45 @@ static void clk_change_rate(struct clk_core *clk) clk_change_rate(clk->new_child); } +static int clk_core_set_rate_nolock(struct clk_core *clk, + unsigned long req_rate) +{ + struct clk_core *top, *fail_clk; + unsigned long rate = req_rate; + int ret = 0; + + if (!clk) + return 0; + + /* bail early if nothing to do */ + if (rate == clk_core_get_rate_nolock(clk)) + return 0; + + if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) + return -EBUSY; + + /* calculate new rates and get the topmost changed clock */ + top = clk_calc_new_rates(clk, rate); + if (!top) + return -EINVAL; + + /* notify that we are about to change rates */ + fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); + if (fail_clk) { + pr_debug("%s: failed to set %s rate\n", __func__, + fail_clk->name); + clk_propagate_rate_change(top, ABORT_RATE_CHANGE); + return -EBUSY; + } + + /* change the rates */ + clk_change_rate(top); + + clk->req_rate = req_rate; + + return ret; +} + /** * clk_set_rate - specify a new rate for clk * @clk: the clk whose rate is being changed @@ -1698,8 +1806,7 @@ static void clk_change_rate(struct clk_core *clk) */ int clk_set_rate(struct clk *clk, unsigned long rate) { - struct clk_core *top, *fail_clk; - int ret = 0; + int ret; if (!clk) return 0; @@ -1707,42 +1814,81 @@ int clk_set_rate(struct clk *clk, unsigned long rate) /* prevent racing with updates to the clock topology */ clk_prepare_lock(); - /* bail early if nothing to do */ - if (rate == clk_get_rate(clk)) - goto out; + ret = clk_core_set_rate_nolock(clk->core, rate); - if ((clk->core->flags & CLK_SET_RATE_GATE) && - clk->core->prepare_count) { - ret = -EBUSY; - goto out; - } + clk_prepare_unlock(); - /* calculate new rates and get the topmost changed clock */ - top = clk_calc_new_rates(clk->core, rate); - if (!top) { - ret = -EINVAL; - goto out; - } + return ret; +} +EXPORT_SYMBOL_GPL(clk_set_rate); - /* notify that we are about to change rates */ - fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); - if (fail_clk) { - pr_debug("%s: failed to set %s rate\n", __func__, - fail_clk->name); - clk_propagate_rate_change(top, ABORT_RATE_CHANGE); - ret = -EBUSY; - goto out; +/** + * clk_set_rate_range - set a rate range for a clock source + * @clk: clock source + * @min: desired minimum clock rate in Hz, inclusive + * @max: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) +{ + int ret = 0; + + if (!clk) + return 0; + + if (min > max) { + pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n", + __func__, clk->core->name, clk->dev_id, clk->con_id, + min, max); + return -EINVAL; } - /* change the rates */ - clk_change_rate(top); + clk_prepare_lock(); + + if (min != clk->min_rate || max != clk->max_rate) { + clk->min_rate = min; + clk->max_rate = max; + ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + } -out: clk_prepare_unlock(); return ret; } -EXPORT_SYMBOL_GPL(clk_set_rate); +EXPORT_SYMBOL_GPL(clk_set_rate_range); + +/** + * clk_set_min_rate - set a minimum clock rate for a clock source + * @clk: clock source + * @rate: desired minimum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_min_rate(struct clk *clk, unsigned long rate) +{ + if (!clk) + return 0; + + return clk_set_rate_range(clk, rate, clk->max_rate); +} +EXPORT_SYMBOL_GPL(clk_set_min_rate); + +/** + * clk_set_max_rate - set a maximum clock rate for a clock source + * @clk: clock source + * @rate: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_max_rate(struct clk *clk, unsigned long rate) +{ + if (!clk) + return 0; + + return clk_set_rate_range(clk, clk->min_rate, rate); +} +EXPORT_SYMBOL_GPL(clk_set_max_rate); /** * clk_get_parent - return the parent of a clk @@ -2038,6 +2184,7 @@ static int __clk_init(struct device *dev, struct clk *clk_user) struct clk_core *orphan; struct hlist_node *tmp2; struct clk_core *clk; + unsigned long rate; if (!clk_user) return -EINVAL; @@ -2162,12 +2309,13 @@ static int __clk_init(struct device *dev, struct clk *clk_user) * then rate is set to zero. */ if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, + rate = clk->ops->recalc_rate(clk->hw, clk_core_get_rate_nolock(clk->parent)); else if (clk->parent) - clk->rate = clk->parent->rate; + rate = clk->parent->rate; else - clk->rate = 0; + rate = 0; + clk->rate = clk->req_rate = rate; /* * walk the list of orphan clocks and reparent any that are children of @@ -2225,10 +2373,24 @@ struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, clk->core = hw->core; clk->dev_id = dev_id; clk->con_id = con_id; + clk->max_rate = ULONG_MAX; + + clk_prepare_lock(); + hlist_add_head(&clk->child_node, &hw->core->clks); + clk_prepare_unlock(); return clk; } +static void __clk_free_clk(struct clk *clk) +{ + clk_prepare_lock(); + hlist_del(&clk->child_node); + clk_prepare_unlock(); + + kfree(clk); +} + /** * clk_register - allocate a new clock, register it and return an opaque cookie * @dev: device that is registering this clock @@ -2288,6 +2450,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) } } + INIT_HLIST_HEAD(&clk->clks); + hw->clk = __clk_create_clk(hw, NULL, NULL); if (IS_ERR(hw->clk)) { pr_err("%s: could not allocate per-user clk\n", __func__); @@ -2299,8 +2463,9 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) if (!ret) return hw->clk; - kfree(hw->clk); + __clk_free_clk(hw->clk); hw->clk = NULL; + fail_parent_names_copy: while (--i >= 0) kfree(clk->parent_names[i]); @@ -2489,25 +2654,24 @@ int __clk_get(struct clk *clk) return 1; } -static void clk_core_put(struct clk_core *core) +void __clk_put(struct clk *clk) { struct module *owner; - owner = core->owner; + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) + return; clk_prepare_lock(); - kref_put(&core->ref, __clk_release); + + hlist_del(&clk->child_node); + clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + owner = clk->core->owner; + kref_put(&clk->core->ref, __clk_release); + clk_prepare_unlock(); module_put(owner); -} - -void __clk_put(struct clk *clk) -{ - if (!clk || WARN_ON_ONCE(IS_ERR(clk))) - return; - clk_core_put(clk->core); kfree(clk); } |