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 --- include/linux/clk-provider.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 1ec14a732176..9487b96939e8 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -327,8 +327,10 @@ struct clk_mux { #define CLK_MUX_INDEX_ONE BIT(0) #define CLK_MUX_INDEX_BIT BIT(1) #define CLK_MUX_HIWORD_MASK BIT(2) +#define CLK_MUX_READ_ONLY BIT(3) /* mux setting cannot be changed */ extern const struct clk_ops clk_mux_ops; +extern const struct clk_ops clk_mux_ro_ops; struct clk *clk_register_mux(struct device *dev, const char *name, const char **parent_names, u8 num_parents, unsigned long flags, -- cgit v1.2.3 From 7ef3dcc8145263cb5a8c7059f82d44c948eb46a8 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 29 Jul 2013 12:24:58 +0100 Subject: clk: abstract parent cache Abstract access to the clock parent cache by defining clk_get_parent_by_index(clk, index). This allows access to parent clocks from clock drivers. Signed-off-by: James Hogan Reviewed-by: Stephen Boyd Cc: Mike Turquette Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Mike Turquette --- include/linux/clk-provider.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 9487b96939e8..a83409285a7f 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -420,6 +420,7 @@ const char *__clk_get_name(struct clk *clk); struct clk_hw *__clk_get_hw(struct clk *clk); u8 __clk_get_num_parents(struct clk *clk); struct clk *__clk_get_parent(struct clk *clk); +struct clk *clk_get_parent_by_index(struct clk *clk, u8 index); unsigned int __clk_get_enable_count(struct clk *clk); unsigned int __clk_get_prepare_count(struct clk *clk); unsigned long __clk_get_rate(struct clk *clk); -- cgit v1.2.3 From 71472c0c06cf9a3d1540762ea205654c584e3bc4 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 29 Jul 2013 12:25:00 +0100 Subject: clk: add support for clock reparent on set_rate Add core support to allow clock implementations to select the best parent clock when rounding a rate, e.g. the one which can provide the closest clock rate to that requested. This is by way of adding a new clock op, determine_rate(), which is like round_rate() but has an extra parameter to allow the clock implementation to optionally select a different parent clock. The core then takes care of reparenting the clock when setting the rate. The parent change takes place with the help of some new private data members. struct clk::new_parent specifies a clock's new parent (NULL indicates no change), and struct clk::new_child specifies a clock's new child (whose new_parent member points back to it). The purpose of these are to allow correct walking of the future tree for notifications prior to actually reparenting any clocks, specifically to skip child clocks who are being reparented to another clock (they will be notified via the new parent), and to include any new child clock. These pointers are set by clk_calc_subtree(), and the new_child pointer gets cleared when a child is actually reparented to avoid duplicate POST_RATE_CHANGE notifications. Each place where round_rate() is called, determine_rate() is checked first and called in preference. This restructures a few of the call sites to simplify the logic into if/else blocks. Signed-off-by: James Hogan Reviewed-by: Stephen Boyd Cc: Mike Turquette Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Mike Turquette --- include/linux/clk-private.h | 3 +++ include/linux/clk-provider.h | 7 +++++++ 2 files changed, 10 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index dd7adff76e81..8138c94409f3 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -33,8 +33,11 @@ struct clk { const char **parent_names; struct clk **parents; u8 num_parents; + u8 new_parent_index; unsigned long rate; unsigned long new_rate; + struct clk *new_parent; + struct clk *new_child; unsigned long flags; unsigned int enable_count; unsigned int prepare_count; diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index a83409285a7f..4f525b37c6fd 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -79,6 +79,10 @@ struct clk_hw; * @round_rate: Given a target rate as input, returns the closest rate actually * supported by the clock. * + * @determine_rate: Given a target rate as input, returns the closest rate + * actually supported by the clock, and optionally the parent clock + * that should be used to provide the clock rate. + * * @get_parent: Queries the hardware to determine the parent of a clock. The * return value is a u8 which specifies the index corresponding to * the parent clock. This index can be applied to either the @@ -126,6 +130,9 @@ struct clk_ops { unsigned long parent_rate); long (*round_rate)(struct clk_hw *hw, unsigned long, unsigned long *); + long (*determine_rate)(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk); int (*set_parent)(struct clk_hw *hw, u8 index); u8 (*get_parent)(struct clk_hw *hw); int (*set_rate)(struct clk_hw *hw, unsigned long, -- cgit v1.2.3 From 819c1de344c5b8350bffd35be9a0fa74541292d3 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Mon, 29 Jul 2013 12:25:01 +0100 Subject: clk: add CLK_SET_RATE_NO_REPARENT flag MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a CLK_SET_RATE_NO_REPARENT clock flag, which will prevent muxes being reparented during clk_set_rate. To avoid breaking existing platforms, all callers of clk_register_mux() are adjusted to pass the new flag. Platform maintainers are encouraged to remove the flag if they wish to allow mux reparenting on set_rate. Signed-off-by: James Hogan Reviewed-by: Stephen Boyd Cc: Mike Turquette Cc: Russell King Cc: Sascha Hauer Cc: Stephen Warren Cc: Viresh Kumar Cc: Kukjin Kim Cc: Haojian Zhuang Cc: Chao Xie Cc: Arnd Bergmann Cc: "Emilio López" Cc: Gregory CLEMENT Cc: Maxime Ripard Cc: Prashant Gaikwad Cc: Thierry Reding Cc: Peter De Schrijver Cc: Pawel Moll Cc: Catalin Marinas Cc: Andrew Chew Cc: Doug Anderson Cc: Heiko Stuebner Cc: Paul Walmsley Cc: Sylwester Nawrocki Cc: Thomas Abraham Cc: Tomasz Figa Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: spear-devel@list.st.com Cc: linux-tegra@vger.kernel.org Tested-by: Haojian Zhuang Acked-by: Stephen Warren [tegra] Acked-by: Maxime Ripard [sunxi] Acked-by: Sören Brinkmann [Zynq] Signed-off-by: Mike Turquette --- include/linux/clk-provider.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 4f525b37c6fd..5c0bc3904c9b 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -27,6 +27,7 @@ #define CLK_IS_ROOT BIT(4) /* root clk, has no parent */ #define CLK_IS_BASIC BIT(5) /* Basic clk, can't do a to_clk_foo() */ #define CLK_GET_RATE_NOCACHE BIT(6) /* do not use the cached clk rate */ +#define CLK_SET_RATE_NO_REPARENT BIT(7) /* don't re-parent on rate change */ struct clk_hw; -- 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 --- include/linux/clk-provider.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') 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 --- include/linux/clk-provider.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux') 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