From e55a839a7a1c561b7d2fbd9cc50b7d40dd2b3361 Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Fri, 1 Dec 2017 22:51:56 +0100 Subject: clk: add clock protection mechanism to clk core The patch adds clk_core_protect and clk_core_unprotect to the internal CCF API. These functions allow to set a new constraint along the clock tree to prevent any change, even indirect, which may result in rate change or glitch. Tested-by: Maxime Ripard Acked-by: Michael Turquette Signed-off-by: Jerome Brunet Signed-off-by: Michael Turquette Link: lkml.kernel.org/r/20171201215200.23523-7-jbrunet@baylibre.com --- 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 7c925e6211f1..73ac87f34df9 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -744,6 +744,7 @@ unsigned long clk_hw_get_rate(const struct clk_hw *hw); unsigned long __clk_get_flags(struct clk *clk); unsigned long clk_hw_get_flags(const struct clk_hw *hw); bool clk_hw_is_prepared(const struct clk_hw *hw); +bool clk_hw_rate_is_protected(const struct clk_hw *hw); bool clk_hw_is_enabled(const struct clk_hw *hw); bool __clk_is_enabled(struct clk *clk); struct clk *__clk_lookup(const char *name); -- cgit v1.2.3 From 55e9b8b7b806ec3f9a8817e13596682a5981c19c Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Fri, 1 Dec 2017 22:51:59 +0100 Subject: clk: add clk_rate_exclusive api Using clock rate protection, we can now provide a way for clock consumer to claim exclusive control over the rate of a producer So far, rate change operations have been a "last write wins" affair. This changes allows drivers to explicitly protect against this behavior, if required. Of course, if exclusivity over a producer is claimed more than once, the rate is effectively locked as exclusivity cannot be preempted Tested-by: Maxime Ripard Acked-by: Michael Turquette Signed-off-by: Jerome Brunet Signed-off-by: Michael Turquette Link: lkml.kernel.org/r/20171201215200.23523-10-jbrunet@baylibre.com --- include/linux/clk.h | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk.h b/include/linux/clk.h index 12c96d94d1fa..4c4ef9f34db3 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -331,6 +331,38 @@ struct clk *devm_clk_get(struct device *dev, const char *id); */ struct clk *devm_get_clk_from_child(struct device *dev, struct device_node *np, const char *con_id); +/** + * clk_rate_exclusive_get - get exclusivity over the rate control of a + * producer + * @clk: clock source + * + * This function allows drivers to get exclusive control over the rate of a + * provider. It prevents any other consumer to execute, even indirectly, + * opereation which could alter the rate of the provider or cause glitches + * + * If exlusivity is claimed more than once on clock, even by the same driver, + * the rate effectively gets locked as exclusivity can't be preempted. + * + * Must not be called from within atomic context. + * + * Returns success (0) or negative errno. + */ +int clk_rate_exclusive_get(struct clk *clk); + +/** + * clk_rate_exclusive_put - release exclusivity over the rate control of a + * producer + * @clk: clock source + * + * This function allows drivers to release the exclusivity it previously got + * from clk_rate_exclusive_get() + * + * The caller must balance the number of clk_rate_exclusive_get() and + * clk_rate_exclusive_put() calls. + * + * Must not be called from within atomic context. + */ +void clk_rate_exclusive_put(struct clk *clk); /** * clk_enable - inform the system when the clock source should be running. @@ -472,6 +504,23 @@ long clk_round_rate(struct clk *clk, unsigned long rate); */ int clk_set_rate(struct clk *clk, unsigned long rate); +/** + * clk_set_rate_exclusive- set the clock rate and claim exclusivity over + * clock source + * @clk: clock source + * @rate: desired clock rate in Hz + * + * This helper function allows drivers to atomically set the rate of a producer + * and claim exclusivity over the rate control of the producer. + * + * It is essentially a combination of clk_set_rate() and + * clk_rate_exclusite_get(). Caller must balance this call with a call to + * clk_rate_exclusive_put() + * + * Returns success (0) or negative errno. + */ +int clk_set_rate_exclusive(struct clk *clk, unsigned long rate); + /** * clk_has_parent - check if a clock is a possible parent for another * @clk: clock source @@ -583,6 +632,14 @@ static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {} static inline void devm_clk_put(struct device *dev, struct clk *clk) {} + +static inline int clk_rate_exclusive_get(struct clk *clk) +{ + return 0; +} + +static inline void clk_rate_exclusive_put(struct clk *clk) {} + static inline int clk_enable(struct clk *clk) { return 0; @@ -609,6 +666,11 @@ static inline int clk_set_rate(struct clk *clk, unsigned long rate) return 0; } +static inline int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) +{ + return 0; +} + static inline long clk_round_rate(struct clk *clk, unsigned long rate) { return 0; -- cgit v1.2.3 From 1ded879e12310b1f8f81b1f84e293933a3b69f14 Mon Sep 17 00:00:00 2001 From: Chunyan Zhang Date: Thu, 7 Dec 2017 20:57:04 +0800 Subject: clk: move clock common macros out from vendor directories These macros are used by more than one SoC vendor platforms, avoid to have many copies of these code, this patch moves them to the common header file which every clock drivers can access to. Signed-off-by: Chunyan Zhang Signed-off-by: Stephen Boyd --- include/linux/clk-provider.h | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 7c925e6211f1..26ea037f88e9 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -806,6 +806,44 @@ extern struct of_device_id __clk_of_table; } \ OF_DECLARE_1(clk, name, compat, name##_of_clk_init_driver) +#define CLK_HW_INIT(_name, _parent, _ops, _flags) \ + (&(struct clk_init_data) { \ + .flags = _flags, \ + .name = _name, \ + .parent_names = (const char *[]) { _parent }, \ + .num_parents = 1, \ + .ops = _ops, \ + }) + +#define CLK_HW_INIT_PARENTS(_name, _parents, _ops, _flags) \ + (&(struct clk_init_data) { \ + .flags = _flags, \ + .name = _name, \ + .parent_names = _parents, \ + .num_parents = ARRAY_SIZE(_parents), \ + .ops = _ops, \ + }) + +#define CLK_HW_INIT_NO_PARENT(_name, _ops, _flags) \ + (&(struct clk_init_data) { \ + .flags = _flags, \ + .name = _name, \ + .parent_names = NULL, \ + .num_parents = 0, \ + .ops = _ops, \ + }) + +#define CLK_FIXED_FACTOR(_struct, _name, _parent, \ + _div, _mult, _flags) \ + struct clk_fixed_factor _struct = { \ + .div = _div, \ + .mult = _mult, \ + .hw.init = CLK_HW_INIT(_name, \ + _parent, \ + &clk_fixed_factor_ops, \ + _flags), \ + } + #ifdef CONFIG_OF int of_clk_add_provider(struct device_node *np, struct clk *(*clk_src_get)(struct of_phandle_args *args, -- cgit v1.2.3 From 51279ef9f64cf7eb8b3f891a2b60fa1aa4938afc Mon Sep 17 00:00:00 2001 From: Sergej Sawazki Date: Sat, 16 Sep 2017 13:44:41 +0200 Subject: clk: si5351: Add DT property to enable PLL reset Add optional output clock DT property to enable PLL reset when a clock output is enabled. Cc: Sebastian Hesselbarth Cc: Rabeeh Khoury Cc: Russell King Signed-off-by: Sergej Sawazki Signed-off-by: Stephen Boyd --- include/linux/platform_data/si5351.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/platform_data/si5351.h b/include/linux/platform_data/si5351.h index 818c5c6e203f..c71a2dd66143 100644 --- a/include/linux/platform_data/si5351.h +++ b/include/linux/platform_data/si5351.h @@ -86,6 +86,7 @@ enum si5351_disable_state { * @multisynth_src: multisynth source clock * @clkout_src: clkout source clock * @pll_master: if true, clkout can also change pll rate + * @pll_reset: if true, clkout can reset its pll * @drive: output drive strength * @rate: initial clkout rate, or default if 0 */ @@ -95,6 +96,7 @@ struct si5351_clkout_config { enum si5351_drive_strength drive; enum si5351_disable_state disable_state; bool pll_master; + bool pll_reset; unsigned long rate; }; -- cgit v1.2.3 From 12a26c298d2a8b1cab498533fa65198e49e3afd3 Mon Sep 17 00:00:00 2001 From: Jerome Brunet Date: Thu, 21 Dec 2017 17:30:54 +0100 Subject: clk: divider: fix incorrect usage of container_of divider_recalc_rate() is an helper function used by clock divider of different types, so the structure containing the 'hw' pointer is not always a 'struct clk_divider' At the following line: > div = _get_div(table, val, flags, divider->width); in several cases, the value of 'divider->width' is garbage as the actual structure behind this memory is not a 'struct clk_divider' Fortunately, this width value is used by _get_val() only when CLK_DIVIDER_MAX_AT_ZERO flag is set. This has never been the case so far when the structure is not a 'struct clk_divider'. This is probably why we did not notice this bug before Fixes: afe76c8fd030 ("clk: allow a clk divider with max divisor when zero") Signed-off-by: Jerome Brunet Acked-by: Alexandre Belloni Acked-by: Sylvain Lemieux Signed-off-by: Stephen Boyd --- include/linux/clk-provider.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 7c925e6211f1..48171b349b88 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -412,7 +412,7 @@ extern const struct clk_ops clk_divider_ro_ops; unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate, unsigned int val, const struct clk_div_table *table, - unsigned long flags); + unsigned long flags, unsigned long width); long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent, unsigned long rate, unsigned long *prate, const struct clk_div_table *table, -- cgit v1.2.3 From 0d4e3d005cb3c7b45463c91b4007d2b9f195879e Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Tue, 2 Jan 2018 15:47:07 -0800 Subject: clk: Prepare to remove asm-generic/clkdev.h Now that all the users of asm/clkdev.h have been replaced with the generic file we can get rid of the asm-generic file as well and implement that code directly where it's used. We only have one caller of __clkdev_alloc(), in clkdev.c so we can easily remove that and drop the include of asm/clkdev.h in linux/clkdev.h by putting the __clk_get/__clk_put inlines in their respective location. Cc: Russell King Signed-off-by: Stephen Boyd --- include/linux/clkdev.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index 2eabc862abdb..ef98ee8c6358 100644 --- a/include/linux/clkdev.h +++ b/include/linux/clkdev.h @@ -12,7 +12,7 @@ #ifndef __CLKDEV_H #define __CLKDEV_H -#include +#include struct clk; struct clk_hw; @@ -55,6 +55,9 @@ int clk_hw_register_clkdev(struct clk_hw *, const char *, const char *); #ifdef CONFIG_COMMON_CLK int __clk_get(struct clk *clk); void __clk_put(struct clk *clk); +#else +static inline int __clk_get(struct clk *clk) { return 1; } +static inline void __clk_put(struct clk *clk) { } #endif #endif -- cgit v1.2.3 From bfc0cbfcad122c27aefad0e00da4f383954cf145 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Tue, 2 Jan 2018 16:54:16 -0800 Subject: clk: Move __clk_{get,put}() into private clk.h API We can move these APIs into the private header file now that we don't have any users of the __clk_get() and __clk_put() APIs outside of clkdev.c and clk.c. Cc: Russell King Signed-off-by: Stephen Boyd --- include/linux/clkdev.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index ef98ee8c6358..4890ff033220 100644 --- a/include/linux/clkdev.h +++ b/include/linux/clkdev.h @@ -52,12 +52,4 @@ int clk_add_alias(const char *, const char *, const char *, struct device *); int clk_register_clkdev(struct clk *, const char *, const char *); int clk_hw_register_clkdev(struct clk_hw *, const char *, const char *); -#ifdef CONFIG_COMMON_CLK -int __clk_get(struct clk *clk); -void __clk_put(struct clk *clk); -#else -static inline int __clk_get(struct clk *clk) { return 1; } -static inline void __clk_put(struct clk *clk) { } -#endif - #endif -- cgit v1.2.3 From a6059ab98130fb561157682d320c51c5ccd4b647 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 3 Jan 2018 12:06:16 +0100 Subject: clk: Show symbolic clock flags in debugfs Currently the virtual "clk_flags" file in debugfs shows the numeric value of the top-level framework flags for the specified clock. Hence the user must manually interpret these values. Moreover, on big-endian 64-bit systems, the wrong half of the value is shown, due to the cast from "unsigned long *" to "u32 *". Fix both issues by showing the symbolic flag names instead. Any non-standard flags are shown as a hex number. Signed-off-by: Geert Uytterhoeven Signed-off-by: Stephen Boyd --- 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 73ac87f34df9..c8236e948659 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -20,6 +20,8 @@ * flags used across common struct clk. these flags should only affect the * top-level framework. custom flags for dealing with hardware specifics * belong in struct clk_foo + * + * Please update clk_flags[] in drivers/clk/clk.c when making changes here! */ #define CLK_SET_RATE_GATE BIT(0) /* must be gated across rate change */ #define CLK_SET_PARENT_GATE BIT(1) /* must be gated across re-parent */ -- cgit v1.2.3