diff options
| -rw-r--r-- | Documentation/devicetree/bindings/metag/meta.txt | 30 | ||||
| -rw-r--r-- | arch/metag/include/asm/clock.h | 8 | ||||
| -rw-r--r-- | arch/metag/kernel/clock.c | 57 | ||||
| -rw-r--r-- | arch/metag/kernel/time.c | 14 |
4 files changed, 106 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/metag/meta.txt b/Documentation/devicetree/bindings/metag/meta.txt new file mode 100644 index 0000000..f4457f5 --- /dev/null +++ b/Documentation/devicetree/bindings/metag/meta.txt @@ -0,0 +1,30 @@ +* Meta Processor Binding + +This binding specifies what properties must be available in the device tree +representation of a Meta Processor Core, which is the root node in the tree. + +Required properties: + + - compatible: Specifies the compatibility list for the Meta processor. + The type shall be <string> and the value shall include "img,meta". + +Optional properties: + + - clocks: Clock consumer specifiers as described in + Documentation/devicetree/bindings/clock/clock-bindings.txt + + - clock-names: Clock consumer names as described in + Documentation/devicetree/bindings/clock/clock-bindings.txt. + +Clocks are identified by name. Valid clocks are: + + - "core": The Meta core clock from which the Meta timers are derived. + +* Examples + +/ { + compatible = "toumaz,tz1090", "img,meta"; + + clocks = <&meta_core_clk>; + clock-names = "core"; +}; diff --git a/arch/metag/include/asm/clock.h b/arch/metag/include/asm/clock.h index 3e2915a..ded4ab2 100644 --- a/arch/metag/include/asm/clock.h +++ b/arch/metag/include/asm/clock.h @@ -19,6 +19,8 @@ * core frequency will be determined like this: * Meta 1: based on loops_per_jiffy. * Meta 2: (EXPAND_TIMER_DIV + 1) MHz. + * If a "core" clock is provided by the device tree, it + * will override this function. */ struct meta_clock_desc { unsigned long (*get_core_freq)(void); @@ -27,6 +29,12 @@ struct meta_clock_desc { extern struct meta_clock_desc _meta_clock; /* + * Perform platform clock initialisation, reading clocks from device tree etc. + * Only accessible during boot. + */ +void init_metag_clocks(void); + +/* * Set up the default clock, ensuring all callbacks are valid - only accessible * during boot. */ diff --git a/arch/metag/kernel/clock.c b/arch/metag/kernel/clock.c index defc840..8bfd6a5 100644 --- a/arch/metag/kernel/clock.c +++ b/arch/metag/kernel/clock.c @@ -8,8 +8,10 @@ * published by the Free Software Foundation. */ +#include <linux/clk.h> #include <linux/delay.h> #include <linux/io.h> +#include <linux/of.h> #include <asm/param.h> #include <asm/clock.h> @@ -34,8 +36,61 @@ static unsigned long get_core_freq_default(void) #endif } +static struct clk *clk_core; + +/* Clk based get_core_freq callback. */ +static unsigned long get_core_freq_clk(void) +{ + return clk_get_rate(clk_core); +} + +/** + * init_metag_core_clock() - Set up core clock from devicetree. + * + * Checks to see if a "core" clock is provided in the device tree, and overrides + * the get_core_freq callback to use it. + */ +static void __init init_metag_core_clock(void) +{ + /* + * See if a core clock is provided by the devicetree (and + * registered by the init callback above). + */ + struct device_node *node; + node = of_find_compatible_node(NULL, NULL, "img,meta"); + if (!node) { + pr_warn("%s: no compatible img,meta DT node found\n", + __func__); + return; + } + + clk_core = of_clk_get_by_name(node, "core"); + if (IS_ERR(clk_core)) { + pr_warn("%s: no core clock found in DT\n", + __func__); + return; + } + + /* + * Override the core frequency callback to use + * this clk. + */ + _meta_clock.get_core_freq = get_core_freq_clk; +} + +/** + * init_metag_clocks() - Set up clocks from devicetree. + * + * Set up important clocks from device tree. In particular any needed for clock + * sources. + */ +void __init init_metag_clocks(void) +{ + init_metag_core_clock(); +} + /** - * setup_meta_clocks() - Set up the Meta clock. + * setup_meta_clocks() - Early set up of the Meta clock. * @desc: Clock descriptor usually provided by machine description * * Ensures all callbacks are valid. diff --git a/arch/metag/kernel/time.c b/arch/metag/kernel/time.c index 17dc107..f1c8c53 100644 --- a/arch/metag/kernel/time.c +++ b/arch/metag/kernel/time.c @@ -5,11 +5,21 @@ * */ -#include <linux/init.h> - #include <clocksource/metag_generic.h> +#include <linux/clk-provider.h> +#include <linux/init.h> +#include <asm/clock.h> void __init time_init(void) { +#ifdef CONFIG_COMMON_CLK + /* Init clocks from device tree */ + of_clk_init(NULL); +#endif + + /* Init meta clocks, particularly the core clock */ + init_metag_clocks(); + + /* Set up the timer clock sources */ metag_generic_timer_init(); } |
