|
@@ -1,6 +1,7 @@
|
|
|
/*
|
|
|
* Copyright (c) 2015 Google, Inc
|
|
|
* Written by Simon Glass <sjg@chromium.org>
|
|
|
+ * Copyright (c) 2016, NVIDIA CORPORATION.
|
|
|
*
|
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
|
*/
|
|
@@ -8,125 +9,166 @@
|
|
|
#ifndef _CLK_H_
|
|
|
#define _CLK_H_
|
|
|
|
|
|
-#include <errno.h>
|
|
|
#include <linux/types.h>
|
|
|
|
|
|
-struct udevice;
|
|
|
+/**
|
|
|
+ * A clock is a hardware signal that oscillates autonomously at a specific
|
|
|
+ * frequency and duty cycle. Most hardware modules require one or more clock
|
|
|
+ * signal to drive their operation. Clock signals are typically generated
|
|
|
+ * externally to the HW module consuming them, by an entity this API calls a
|
|
|
+ * clock provider. This API provides a standard means for drivers to enable and
|
|
|
+ * disable clocks, and to set the rate at which they oscillate.
|
|
|
+ *
|
|
|
+ * A driver that implements UCLASS_CLOCK is a clock provider. A provider will
|
|
|
+ * often implement multiple separate clocks, since the hardware it manages
|
|
|
+ * often has this capability. clock_uclass.h describes the interface which
|
|
|
+ * clock providers must implement.
|
|
|
+ *
|
|
|
+ * Clock consumers/clients are the HW modules driven by the clock signals. This
|
|
|
+ * header file describes the API used by drivers for those HW modules.
|
|
|
+ */
|
|
|
|
|
|
-int soc_clk_dump(void);
|
|
|
+struct udevice;
|
|
|
|
|
|
-struct clk_ops {
|
|
|
- /**
|
|
|
- * get_rate() - Get current clock rate
|
|
|
- *
|
|
|
- * @dev: Device to check (UCLASS_CLK)
|
|
|
- * @return clock rate in Hz, or -ve error code
|
|
|
- */
|
|
|
- ulong (*get_rate)(struct udevice *dev);
|
|
|
-
|
|
|
- /**
|
|
|
- * set_rate() - Set current clock rate
|
|
|
- *
|
|
|
- * @dev: Device to adjust
|
|
|
- * @rate: New clock rate in Hz
|
|
|
- * @return new rate, or -ve error code
|
|
|
- */
|
|
|
- ulong (*set_rate)(struct udevice *dev, ulong rate);
|
|
|
-
|
|
|
- /**
|
|
|
- * enable() - Enable the clock for a peripheral
|
|
|
- *
|
|
|
- * @dev: clock provider
|
|
|
- * @periph: Peripheral ID to enable
|
|
|
- * @return zero on success, or -ve error code
|
|
|
- */
|
|
|
- int (*enable)(struct udevice *dev, int periph);
|
|
|
-
|
|
|
- /**
|
|
|
- * get_periph_rate() - Get clock rate for a peripheral
|
|
|
- *
|
|
|
- * @dev: Device to check (UCLASS_CLK)
|
|
|
- * @periph: Peripheral ID to check
|
|
|
- * @return clock rate in Hz, or -ve error code
|
|
|
- */
|
|
|
- ulong (*get_periph_rate)(struct udevice *dev, int periph);
|
|
|
-
|
|
|
- /**
|
|
|
- * set_periph_rate() - Set current clock rate for a peripheral
|
|
|
- *
|
|
|
- * @dev: Device to update (UCLASS_CLK)
|
|
|
- * @periph: Peripheral ID to update
|
|
|
- * @return new clock rate in Hz, or -ve error code
|
|
|
+/**
|
|
|
+ * struct clk - A handle to (allowing control of) a single clock.
|
|
|
+ *
|
|
|
+ * Clients provide storage for clock handles. The content of the structure is
|
|
|
+ * managed solely by the clock API and clock drivers. A clock struct is
|
|
|
+ * initialized by "get"ing the clock struct. The clock struct is passed to all
|
|
|
+ * other clock APIs to identify which clock signal to operate upon.
|
|
|
+ *
|
|
|
+ * @dev: The device which implements the clock signal.
|
|
|
+ * @id: The clock signal ID within the provider.
|
|
|
+ *
|
|
|
+ * Currently, the clock API assumes that a single integer ID is enough to
|
|
|
+ * identify and configure any clock signal for any clock provider. If this
|
|
|
+ * assumption becomes invalid in the future, the struct could be expanded to
|
|
|
+ * either (a) add more fields to allow clock providers to store additional
|
|
|
+ * information, or (b) replace the id field with an opaque pointer, which the
|
|
|
+ * provider would dynamically allocated during its .of_xlate op, and process
|
|
|
+ * during is .request op. This may require the addition of an extra op to clean
|
|
|
+ * up the allocation.
|
|
|
+ */
|
|
|
+struct clk {
|
|
|
+ struct udevice *dev;
|
|
|
+ /*
|
|
|
+ * Written by of_xlate. We assume a single id is enough for now. In the
|
|
|
+ * future, we might add more fields here.
|
|
|
*/
|
|
|
- ulong (*set_periph_rate)(struct udevice *dev, int periph, ulong rate);
|
|
|
+ unsigned long id;
|
|
|
};
|
|
|
|
|
|
-#define clk_get_ops(dev) ((struct clk_ops *)(dev)->driver->ops)
|
|
|
+#if CONFIG_IS_ENABLED(OF_CONTROL)
|
|
|
+/**
|
|
|
+ * clock_get_by_index - Get/request a clock by integer index.
|
|
|
+ *
|
|
|
+ * This looks up and requests a clock. The index is relative to the client
|
|
|
+ * device; each device is assumed to have n clocks associated with it somehow,
|
|
|
+ * and this function finds and requests one of them. The mapping of client
|
|
|
+ * device clock indices to provider clocks may be via device-tree properties,
|
|
|
+ * board-provided mapping tables, or some other mechanism.
|
|
|
+ *
|
|
|
+ * @dev: The client device.
|
|
|
+ * @index: The index of the clock to request, within the client's list of
|
|
|
+ * clocks.
|
|
|
+ * @clock A pointer to a clock struct to initialize.
|
|
|
+ * @return 0 if OK, or a negative error code.
|
|
|
+ */
|
|
|
+int clk_get_by_index(struct udevice *dev, int index, struct clk *clk);
|
|
|
|
|
|
/**
|
|
|
- * clk_get_rate() - Get current clock rate
|
|
|
+ * clock_get_by_name - Get/request a clock by name.
|
|
|
*
|
|
|
- * @dev: Device to check (UCLASS_CLK)
|
|
|
- * @return clock rate in Hz, or -ve error code
|
|
|
+ * This looks up and requests a clock. The name is relative to the client
|
|
|
+ * device; each device is assumed to have n clocks associated with it somehow,
|
|
|
+ * and this function finds and requests one of them. The mapping of client
|
|
|
+ * device clock names to provider clocks may be via device-tree properties,
|
|
|
+ * board-provided mapping tables, or some other mechanism.
|
|
|
+ *
|
|
|
+ * @dev: The client device.
|
|
|
+ * @name: The name of the clock to request, within the client's list of
|
|
|
+ * clocks.
|
|
|
+ * @clock: A pointer to a clock struct to initialize.
|
|
|
+ * @return 0 if OK, or a negative error code.
|
|
|
*/
|
|
|
-ulong clk_get_rate(struct udevice *dev);
|
|
|
+int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
|
|
|
+#else
|
|
|
+static inline int clk_get_by_index(struct udevice *dev, int index,
|
|
|
+ struct clk *clk)
|
|
|
+{
|
|
|
+ return -ENOSYS;
|
|
|
+}
|
|
|
+
|
|
|
+static int clk_get_by_name(struct udevice *dev, const char *name,
|
|
|
+ struct clk *clk)
|
|
|
+{
|
|
|
+ return -ENOSYS;
|
|
|
+}
|
|
|
+#endif
|
|
|
|
|
|
/**
|
|
|
- * clk_set_rate() - Set current clock rate
|
|
|
+ * clk_request - Request a clock by provider-specific ID.
|
|
|
*
|
|
|
- * @dev: Device to adjust
|
|
|
- * @rate: New clock rate in Hz
|
|
|
- * @return new rate, or -ve error code
|
|
|
+ * This requests a clock using a provider-specific ID. Generally, this function
|
|
|
+ * should not be used, since clk_get_by_index/name() provide an interface that
|
|
|
+ * better separates clients from intimate knowledge of clock providers.
|
|
|
+ * However, this function may be useful in core SoC-specific code.
|
|
|
+ *
|
|
|
+ * @dev: The clock provider device.
|
|
|
+ * @clock: A pointer to a clock struct to initialize. The caller must
|
|
|
+ * have already initialized any field in this struct which the
|
|
|
+ * clock provider uses to identify the clock.
|
|
|
+ * @return 0 if OK, or a negative error code.
|
|
|
*/
|
|
|
-ulong clk_set_rate(struct udevice *dev, ulong rate);
|
|
|
+int clk_request(struct udevice *dev, struct clk *clk);
|
|
|
|
|
|
/**
|
|
|
- * clk_enable() - Enable the clock for a peripheral
|
|
|
+ * clock_free - Free a previously requested clock.
|
|
|
*
|
|
|
- * @dev: clock provider
|
|
|
- * @periph: Peripheral ID to enable
|
|
|
- * @return zero on success, or -ve error code
|
|
|
+ * @clock: A clock struct that was previously successfully requested by
|
|
|
+ * clk_request/get_by_*().
|
|
|
+ * @return 0 if OK, or a negative error code.
|
|
|
*/
|
|
|
-int clk_enable(struct udevice *dev, int periph);
|
|
|
+int clk_free(struct clk *clk);
|
|
|
|
|
|
/**
|
|
|
- * clk_get_periph_rate() - Get current clock rate for a peripheral
|
|
|
+ * clk_get_rate() - Get current clock rate.
|
|
|
*
|
|
|
- * @dev: Device to check (UCLASS_CLK)
|
|
|
- * @return clock rate in Hz, -ve error code
|
|
|
+ * @clk: A clock struct that was previously successfully requested by
|
|
|
+ * clk_request/get_by_*().
|
|
|
+ * @return clock rate in Hz, or -ve error code.
|
|
|
*/
|
|
|
-ulong clk_get_periph_rate(struct udevice *dev, int periph);
|
|
|
+ulong clk_get_rate(struct clk *clk);
|
|
|
|
|
|
/**
|
|
|
- * clk_set_periph_rate() - Set current clock rate for a peripheral
|
|
|
+ * clk_set_rate() - Set current clock rate.
|
|
|
*
|
|
|
- * @dev: Device to update (UCLASS_CLK)
|
|
|
- * @periph: Peripheral ID to update
|
|
|
- * @return new clock rate in Hz, or -ve error code
|
|
|
+ * @clk: A clock struct that was previously successfully requested by
|
|
|
+ * clk_request/get_by_*().
|
|
|
+ * @rate: New clock rate in Hz.
|
|
|
+ * @return new rate, or -ve error code.
|
|
|
*/
|
|
|
-ulong clk_set_periph_rate(struct udevice *dev, int periph, ulong rate);
|
|
|
+ulong clk_set_rate(struct clk *clk, ulong rate);
|
|
|
|
|
|
-#if CONFIG_IS_ENABLED(OF_CONTROL)
|
|
|
/**
|
|
|
- * clk_get_by_index() - look up a clock referenced by a device
|
|
|
+ * clk_enable() - Enable (turn on) a clock.
|
|
|
*
|
|
|
- * Parse a device's 'clocks' list, returning information on the indexed clock,
|
|
|
- * ensuring that it is activated.
|
|
|
+ * @clk: A clock struct that was previously successfully requested by
|
|
|
+ * clk_request/get_by_*().
|
|
|
+ * @return zero on success, or -ve error code.
|
|
|
+ */
|
|
|
+int clk_enable(struct clk *clk);
|
|
|
+
|
|
|
+/**
|
|
|
+ * clk_disable() - Disable (turn off) a clock.
|
|
|
*
|
|
|
- * @dev: Device containing the clock reference
|
|
|
- * @index: Clock index to return (0 = first)
|
|
|
- * @clk_devp: Returns clock device
|
|
|
- * @return: Peripheral ID for the device to control. This is the first
|
|
|
- * argument after the clock node phandle. If there is no arguemnt,
|
|
|
- * returns 0. Return -ve error code on any error
|
|
|
+ * @clk: A clock struct that was previously successfully requested by
|
|
|
+ * clk_request/get_by_*().
|
|
|
+ * @return zero on success, or -ve error code.
|
|
|
*/
|
|
|
-int clk_get_by_index(struct udevice *dev, int index, struct udevice **clk_devp);
|
|
|
-#else
|
|
|
-static inline int clk_get_by_index(struct udevice *dev, int index,
|
|
|
- struct udevice **clk_devp)
|
|
|
-{
|
|
|
- return -ENOSYS;
|
|
|
-}
|
|
|
-#endif
|
|
|
+int clk_disable(struct clk *clk);
|
|
|
|
|
|
-#endif /* _CLK_H_ */
|
|
|
+int soc_clk_dump(void);
|
|
|
+
|
|
|
+#endif
|