diff options
| -rw-r--r-- | Documentation/devicetree/bindings/clock/clock-bindings.txt | 36 | ||||
| -rw-r--r-- | drivers/base/platform.c | 5 | ||||
| -rw-r--r-- | drivers/clk/Makefile | 3 | ||||
| -rw-r--r-- | drivers/clk/clk-conf.c | 143 | ||||
| -rw-r--r-- | drivers/clk/clk.c | 12 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.c | 5 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 5 | ||||
| -rw-r--r-- | include/linux/clk/clk-conf.h | 20 |
8 files changed, 227 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index f157878..06fc6d5 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -131,3 +131,39 @@ clock signal, and a UART. ("pll" and "pll-switched"). * The UART has its baud clock connected the external oscillator and its register clock connected to the PLL clock (the "pll-switched" signal) + +==Assigned clock parents and rates== + +Some platforms may require initial configuration of default parent clocks +and clock frequencies. Such a configuration can be specified in a device tree +node through assigned-clocks, assigned-clock-parents and assigned-clock-rates +properties. The assigned-clock-parents property should contain a list of parent +clocks in form of phandle and clock specifier pairs, the assigned-clock-parents +property the list of assigned clock frequency values - corresponding to clocks +listed in the assigned-clocks property. + +To skip setting parent or rate of a clock its corresponding entry should be +set to 0, or can be omitted if it is not followed by any non-zero entry. + + uart@a000 { + compatible = "fsl,imx-uart"; + reg = <0xa000 0x1000>; + ... + clocks = <&osc 0>, <&pll 1>; + clock-names = "baud", "register"; + + assigned-clocks = <&clkcon 0>, <&pll 2>; + assigned-clock-parents = <&pll 2>; + assigned-clock-rates = <0>, <460800>; + }; + +In this example the <&pll 2> clock is set as parent of clock <&clkcon 0> and +the <&pll 2> clock is assigned a frequency value of 460800 Hz. + +Configuring a clock's parent and rate through the device node that consumes +the clock can be done only for clocks that have a single user. Specifying +conflicting parent or rate configuration in multiple consumer nodes for +a shared clock is forbidden. + +Configuration of common clocks, which affect multiple consumer devices can +be similarly specified in the clock provider node. diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 9e9227e..ac47643 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -23,6 +23,7 @@ #include <linux/pm_runtime.h> #include <linux/idr.h> #include <linux/acpi.h> +#include <linux/clk/clk-conf.h> #include "base.h" #include "power/power.h" @@ -489,6 +490,10 @@ static int platform_drv_probe(struct device *_dev) struct platform_device *dev = to_platform_device(_dev); int ret; + ret = of_clk_set_defaults(_dev->of_node, false); + if (ret < 0) + return ret; + acpi_dev_pm_attach(_dev, true); ret = drv->probe(dev); diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 312742c..d5d325f 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -9,6 +9,9 @@ obj-$(CONFIG_COMMON_CLK) += clk-gate.o obj-$(CONFIG_COMMON_CLK) += clk-mux.o obj-$(CONFIG_COMMON_CLK) += clk-composite.o obj-$(CONFIG_COMMON_CLK) += clk-fractional-divider.o +ifeq ($(CONFIG_OF), y) +obj-$(CONFIG_COMMON_CLK) += clk-conf.o +endif # hardware specific clock types # please keep this section sorted lexicographically by file/directory path name diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c new file mode 100644 index 0000000..1f73019 --- /dev/null +++ b/drivers/clk/clk-conf.c @@ -0,0 +1,143 @@ +/* + * Copyright (C) 2014 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawrocki@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/clk/clk-conf.h> +#include <linux/device.h> +#include <linux/of.h> +#include <linux/printk.h> +#include "clk.h" + +static int __set_clk_parents(struct device_node *node, bool clk_supplier) +{ + struct of_phandle_args clkspec; + int index, rc, num_parents; + struct clk *clk, *pclk; + + num_parents = of_count_phandle_with_args(node, "assigned-clock-parents", + "#clock-cells"); + if (num_parents == -EINVAL) + pr_err("clk: invalid value of clock-parents property at %s\n", + node->full_name); + + for (index = 0; index < num_parents; index++) { + rc = of_parse_phandle_with_args(node, "assigned-clock-parents", + "#clock-cells", index, &clkspec); + if (rc < 0) { + /* skip empty (null) phandles */ + if (rc == -ENOENT) + continue; + else + return rc; + } + if (clkspec.np == node && !clk_supplier) + return 0; + pclk = of_clk_get_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + return PTR_ERR(pclk); + } + + rc = of_parse_phandle_with_args(node, "assigned-clocks", + "#clock-cells", index, &clkspec); + if (rc < 0) + goto err; + if (clkspec.np == node && !clk_supplier) { + rc = 0; + goto err; + } + clk = of_clk_get_by_clkspec(&clkspec); + if (IS_ERR(pclk)) { + pr_warn("clk: couldn't get parent clock %d for %s\n", + index, node->full_name); + rc = PTR_ERR(pclk); + goto err; + } + + rc = clk_set_parent(clk, pclk); + if (rc < 0) + pr_err("clk: failed to reparent %s to %s: %d\n", + __clk_get_name(clk), __clk_get_name(pclk), rc); + clk_put(clk); + clk_put(pclk); + } + return 0; +err: + clk_put(pclk); + return rc; +} + +static int __set_clk_rates(struct device_node *node, bool clk_supplier) +{ + struct of_phandle_args clkspec; + struct property *prop; + const __be32 *cur; + int rc, index = 0; + struct clk *clk; + u32 rate; + + of_property_for_each_u32(node, "assigned-clock-rates", prop, cur, rate) { + if (rate) { + rc = of_parse_phandle_with_args(node, "assigned-clocks", + "#clock-cells", index, &clkspec); + if (rc < 0) { + /* skip empty (null) phandles */ + if (rc == -ENOENT) + continue; + else + return rc; + } + if (clkspec.np == node && !clk_supplier) + return 0; + + clk = of_clk_get_by_clkspec(&clkspec); + if (IS_ERR(clk)) { + pr_warn("clk: couldn't get clock %d for %s\n", + index, node->full_name); + return PTR_ERR(clk); + } + + rc = clk_set_rate(clk, rate); + if (rc < 0) + pr_err("clk: couldn't set %s clock rate: %d\n", + __clk_get_name(clk), rc); + clk_put(clk); + } + index++; + } + return 0; +} + +/** + * of_clk_set_defaults() - parse and set assigned clocks configuration + * @node: device node to apply clock settings for + * @clk_supplier: true if clocks supplied by @node should also be considered + * + * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties + * and sets any specified clock parents and rates. The @clk_supplier argument + * should be set to true if @node may be also a clock supplier of any clock + * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties. + * If @clk_supplier is false the function exits returnning 0 as soon as it + * determines the @node is also a supplier of any of the clocks. + */ +int of_clk_set_defaults(struct device_node *node, bool clk_supplier) +{ + int rc; + + if (!node) + return 0; + + rc = __set_clk_parents(node, clk_supplier); + if (rc < 0) + return rc; + + return __set_clk_rates(node, clk_supplier); +} diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 9ad3970..f95590a 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -10,6 +10,7 @@ */ #include <linux/clk-private.h> +#include <linux/clk/clk-conf.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/spinlock.h> @@ -2382,6 +2383,7 @@ int of_clk_add_provider(struct device_node *np, void *data) { struct of_clk_provider *cp; + int ret; cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); if (!cp) @@ -2396,7 +2398,11 @@ int of_clk_add_provider(struct device_node *np, mutex_unlock(&of_clk_mutex); pr_debug("Added clock from %s\n", np->full_name); - return 0; + ret = of_clk_set_defaults(np, true); + if (ret < 0) + of_clk_del_provider(np); + + return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider); @@ -2573,7 +2579,10 @@ void __init of_clk_init(const struct of_device_id *matches) list_for_each_entry_safe(clk_provider, next, &clk_provider_list, node) { if (force || parent_ready(clk_provider->np)) { + clk_provider->clk_init_cb(clk_provider->np); + of_clk_set_defaults(clk_provider->np, true); + list_del(&clk_provider->node); kfree(clk_provider); is_init_done = true; @@ -2588,7 +2597,6 @@ void __init of_clk_init(const struct of_device_id *matches) */ if (!is_init_done) force = true; - } } #endif diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 7c7f4b8..66aa83b 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -42,6 +42,7 @@ #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_irq.h> +#include <linux/clk/clk-conf.h> #include <linux/completion.h> #include <linux/hardirq.h> #include <linux/irqflags.h> @@ -274,6 +275,10 @@ static int i2c_device_probe(struct device *dev) client->flags & I2C_CLIENT_WAKE); dev_dbg(dev, "probe\n"); + status = of_clk_set_defaults(dev->of_node, false); + if (status < 0) + return status; + acpi_dev_pm_attach(&client->dev, true); status = driver->probe(client, i2c_match_id(driver->id_table, client)); if (status) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d4f9670..22aa41c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -29,6 +29,7 @@ #include <linux/mutex.h> #include <linux/of_device.h> #include <linux/of_irq.h> +#include <linux/clk/clk-conf.h> #include <linux/slab.h> #include <linux/mod_devicetable.h> #include <linux/spi/spi.h> @@ -259,6 +260,10 @@ static int spi_drv_probe(struct device *dev) const struct spi_driver *sdrv = to_spi_driver(dev->driver); int ret; + ret = of_clk_set_defaults(dev->of_node, false); + if (ret) + return ret; + acpi_dev_pm_attach(dev, true); ret = sdrv->probe(to_spi_device(dev)); if (ret) diff --git a/include/linux/clk/clk-conf.h b/include/linux/clk/clk-conf.h new file mode 100644 index 0000000..f3050e1 --- /dev/null +++ b/include/linux/clk/clk-conf.h @@ -0,0 +1,20 @@ +/* + * Copyright (C) 2014 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawrocki@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +struct device_node; + +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +int of_clk_set_defaults(struct device_node *node, bool clk_supplier); +#else +static inline int of_clk_set_defaults(struct device_node *node, + bool clk_supplier) +{ + return 0; +} +#endif |