From c57acd14ac2d53e40f5c17701c3cc3a092a07b35 Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Tue, 23 Jul 2013 01:49:18 +0200 Subject: clk: mux: Add support for read-only muxes. Some platforms have read-only clock muxes that are preconfigured at reset and cannot be changed at runtime. This patch extends mux clock driver to allow handling such read-only muxes by adding new CLK_MUX_READ_ONLY mux flag. Signed-off-by: Tomasz Figa Signed-off-by: Mike Turquette --- drivers/clk/clk-mux.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'drivers/clk/clk-mux.c') diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index 614444ca40cd..92f1a1be5319 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -107,6 +107,11 @@ const struct clk_ops clk_mux_ops = { }; EXPORT_SYMBOL_GPL(clk_mux_ops); +const struct clk_ops clk_mux_ro_ops = { + .get_parent = clk_mux_get_parent, +}; +EXPORT_SYMBOL_GPL(clk_mux_ro_ops); + struct clk *clk_register_mux_table(struct device *dev, const char *name, const char **parent_names, u8 num_parents, unsigned long flags, void __iomem *reg, u8 shift, u32 mask, @@ -133,7 +138,10 @@ struct clk *clk_register_mux_table(struct device *dev, const char *name, } init.name = name; - init.ops = &clk_mux_ops; + if (clk_mux_flags & CLK_MUX_READ_ONLY) + init.ops = &clk_mux_ro_ops; + else + init.ops = &clk_mux_ops; init.flags = flags | CLK_IS_BASIC; init.parent_names = parent_names; init.num_parents = num_parents; -- cgit v1.2.3 From 5cfe10bb00e1b8c0aaa3f0c796c643bb1af6db82 Mon Sep 17 00:00:00 2001 From: Mike Turquette Date: Thu, 15 Aug 2013 19:06:29 -0700 Subject: clk: export fixed-factor, gate & mux registration These registration calls may be used by loadable modules. Export them. Signed-off-by: Mike Turquette --- drivers/clk/clk-fixed-factor.c | 2 ++ drivers/clk/clk-gate.c | 1 + drivers/clk/clk-mux.c | 2 ++ 3 files changed, 5 insertions(+) (limited to 'drivers/clk/clk-mux.c') diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c index 9ff7d510faa3..0e1d89b4321b 100644 --- a/drivers/clk/clk-fixed-factor.c +++ b/drivers/clk/clk-fixed-factor.c @@ -97,6 +97,8 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name, return clk; } +EXPORT_SYMBOL_GPL(clk_register_fixed_factor); + #ifdef CONFIG_OF /** * of_fixed_factor_clk_setup() - Setup function for simple fixed factor clock diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c index 790306e921c8..2b28a004c19e 100644 --- a/drivers/clk/clk-gate.c +++ b/drivers/clk/clk-gate.c @@ -161,3 +161,4 @@ struct clk *clk_register_gate(struct device *dev, const char *name, return clk; } +EXPORT_SYMBOL_GPL(clk_register_gate); diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index 92f1a1be5319..b918dc370bd0 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -162,6 +162,7 @@ struct clk *clk_register_mux_table(struct device *dev, const char *name, return clk; } +EXPORT_SYMBOL_GPL(clk_register_mux_table); struct clk *clk_register_mux(struct device *dev, const char *name, const char **parent_names, u8 num_parents, unsigned long flags, @@ -174,3 +175,4 @@ struct clk *clk_register_mux(struct device *dev, const char *name, flags, reg, shift, mask, clk_mux_flags, NULL, lock); } +EXPORT_SYMBOL_GPL(clk_register_mux); -- cgit v1.2.3 From e366fdd72529c545ccf327569ee250c1673be221 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 29 Jul 2013 12:25:02 +0100 Subject: clk: clk-mux: implement remuxing on set_rate Implement clk-mux remuxing if the CLK_SET_RATE_NO_REPARENT flag isn't set. This implements determine_rate for clk-mux to propagate to each parent and to choose the best one (like clk-divider this chooses the parent which provides the fastest rate <= the requested rate). The determine_rate op is implemented as a core helper function so that it can be easily used by more complex clocks which incorporate muxes. Signed-off-by: James Hogan Reviewed-by: Stephen Boyd Cc: Mike Turquette Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Mike Turquette --- drivers/clk/clk-mux.c | 1 + drivers/clk/clk.c | 49 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/clk-provider.h | 3 +++ 3 files changed, 53 insertions(+) (limited to 'drivers/clk/clk-mux.c') diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index b918dc370bd0..0811633fcc4d 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -104,6 +104,7 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index) const struct clk_ops clk_mux_ops = { .get_parent = clk_mux_get_parent, .set_parent = clk_mux_set_parent, + .determine_rate = __clk_mux_determine_rate, }; EXPORT_SYMBOL_GPL(clk_mux_ops); diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index f33f1ccf1b2f..bc020372106b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -692,6 +692,55 @@ struct clk *__clk_lookup(const char *name) return NULL; } +/* + * 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 *best_parent_rate, + struct clk **best_parent_p) +{ + struct clk *clk = hw->clk, *parent, *best_parent = NULL; + int i, num_parents; + unsigned long parent_rate, best = 0; + + /* if NO_REPARENT flag set, pass through to current parent */ + if (clk->flags & CLK_SET_RATE_NO_REPARENT) { + parent = clk->parent; + if (clk->flags & CLK_SET_RATE_PARENT) + best = __clk_round_rate(parent, rate); + else if (parent) + best = __clk_get_rate(parent); + else + best = __clk_get_rate(clk); + goto out; + } + + /* find the parent that can provide the fastest rate <= rate */ + num_parents = clk->num_parents; + for (i = 0; i < num_parents; i++) { + parent = clk_get_parent_by_index(clk, i); + if (!parent) + continue; + if (clk->flags & CLK_SET_RATE_PARENT) + parent_rate = __clk_round_rate(parent, rate); + else + parent_rate = __clk_get_rate(parent); + if (parent_rate <= rate && parent_rate > best) { + best_parent = parent; + best = parent_rate; + } + } + +out: + if (best_parent) + *best_parent_p = best_parent; + *best_parent_rate = best; + + return best; +} + /*** clk api ***/ void __clk_unprepare(struct clk *clk) diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 5c0bc3904c9b..1f0285b2f422 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -436,6 +436,9 @@ unsigned long __clk_get_flags(struct clk *clk); bool __clk_is_prepared(struct clk *clk); bool __clk_is_enabled(struct clk *clk); struct clk *__clk_lookup(const char *name); +long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_p); /* * FIXME clock api without lock protection -- cgit v1.2.3 From aa514ce34b65e3dc01f95a0b470b39bbb7e09998 Mon Sep 17 00:00:00 2001 From: Gerhard Sittig Date: Mon, 22 Jul 2013 14:14:40 +0200 Subject: clk: wrap I/O access for improved portability the common clock drivers were motivated/initiated by ARM development and apparently assume little endian peripherals wrap register/peripherals access in the common code (div, gate, mux) in preparation of adding COMMON_CLK support for other platforms Signed-off-by: Gerhard Sittig Signed-off-by: Mike Turquette --- drivers/clk/clk-divider.c | 6 +++--- drivers/clk/clk-gate.c | 6 +++--- drivers/clk/clk-mux.c | 6 +++--- include/linux/clk-provider.h | 17 +++++++++++++++++ 4 files changed, 26 insertions(+), 9 deletions(-) (limited to 'drivers/clk/clk-mux.c') diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 749372f87ec4..8d3009e44fba 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -104,7 +104,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw, struct clk_divider *divider = to_clk_divider(hw); unsigned int div, val; - val = readl(divider->reg) >> divider->shift; + val = clk_readl(divider->reg) >> divider->shift; val &= div_mask(divider); div = _get_div(divider, val); @@ -230,11 +230,11 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, if (divider->flags & CLK_DIVIDER_HIWORD_MASK) { val = div_mask(divider) << (divider->shift + 16); } else { - val = readl(divider->reg); + val = clk_readl(divider->reg); val &= ~(div_mask(divider) << divider->shift); } val |= value << divider->shift; - writel(val, divider->reg); + clk_writel(val, divider->reg); if (divider->lock) spin_unlock_irqrestore(divider->lock, flags); diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c index 2b28a004c19e..4a58c55255bd 100644 --- a/drivers/clk/clk-gate.c +++ b/drivers/clk/clk-gate.c @@ -58,7 +58,7 @@ static void clk_gate_endisable(struct clk_hw *hw, int enable) if (set) reg |= BIT(gate->bit_idx); } else { - reg = readl(gate->reg); + reg = clk_readl(gate->reg); if (set) reg |= BIT(gate->bit_idx); @@ -66,7 +66,7 @@ static void clk_gate_endisable(struct clk_hw *hw, int enable) reg &= ~BIT(gate->bit_idx); } - writel(reg, gate->reg); + clk_writel(reg, gate->reg); if (gate->lock) spin_unlock_irqrestore(gate->lock, flags); @@ -89,7 +89,7 @@ static int clk_gate_is_enabled(struct clk_hw *hw) u32 reg; struct clk_gate *gate = to_clk_gate(hw); - reg = readl(gate->reg); + reg = clk_readl(gate->reg); /* if a set bit disables this clk, flip it before masking */ if (gate->flags & CLK_GATE_SET_TO_DISABLE) diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c index 0811633fcc4d..4f96ff3ba728 100644 --- a/drivers/clk/clk-mux.c +++ b/drivers/clk/clk-mux.c @@ -42,7 +42,7 @@ static u8 clk_mux_get_parent(struct clk_hw *hw) * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so * val = 0x4 really means "bit 2, index starts at bit 0" */ - val = readl(mux->reg) >> mux->shift; + val = clk_readl(mux->reg) >> mux->shift; val &= mux->mask; if (mux->table) { @@ -89,11 +89,11 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index) if (mux->flags & CLK_MUX_HIWORD_MASK) { val = mux->mask << (mux->shift + 16); } else { - val = readl(mux->reg); + val = clk_readl(mux->reg); val &= ~(mux->mask << mux->shift); } val |= index << mux->shift; - writel(val, mux->reg); + clk_writel(val, mux->reg); if (mux->lock) spin_unlock_irqrestore(mux->lock, flags); diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 1f0285b2f422..73bdb69f0c08 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -12,6 +12,7 @@ #define __LINUX_CLK_PROVIDER_H #include +#include #ifdef CONFIG_COMMON_CLK @@ -504,5 +505,21 @@ static inline const char *of_clk_get_parent_name(struct device_node *np, #define of_clk_init(matches) \ { while (0); } #endif /* CONFIG_OF */ + +/* + * wrap access to peripherals in accessor routines + * for improved portability across platforms + */ + +static inline u32 clk_readl(u32 __iomem *reg) +{ + return readl(reg); +} + +static inline void clk_writel(u32 val, u32 __iomem *reg) +{ + writel(val, reg); +} + #endif /* CONFIG_COMMON_CLK */ #endif /* CLK_PROVIDER_H */ -- cgit v1.2.3