clk: convert API to match reset/mailbox style

The following changes are made to the clock API:
* The concept of "clocks" and "peripheral clocks" are unified; each clock
  provider now implements a single set of clocks. This provides a simpler
  conceptual interface to clients, and better aligns with device tree
  clock bindings.
* Clocks are now identified with a single "struct clk", rather than
  requiring clients to store the clock provider device and clock identity
  values separately. For simple clock consumers, this isolates clients
  from internal details of the clock API.
* clk.h is split so it only contains the client/consumer API, whereas
  clk-uclass.h contains the provider API. This aligns with the recently
  added reset and mailbox APIs.
* clk_ops .of_xlate(), .request(), and .free() are added so providers
  can customize these operations if needed. This also aligns with the
  recently added reset and mailbox APIs.
* clk_disable() is added.
* All users of the current clock APIs are updated.
* Sandbox clock tests are updated to exercise clock lookup via DT, and
  clock enable/disable.
* rkclk_get_clk() is removed and replaced with standard APIs.

Buildman shows no clock-related errors for any board for which buildman
can download a toolchain.

test/py passes for sandbox (which invokes the dm clk test amongst
others).

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

1 files changed, 95 insertions, 0 deletions

diff --git a/include/clk-uclass.h b/include/clk-uclass.h
new file mode 100644
index 00000000000..07c10654955
--- /dev/null
+++ b/include/clk-uclass.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _CLK_UCLASS_H
+#define _CLK_UCLASS_H
+
+/* See clk.h for background documentation. */
+
+#include <clk.h>
+#include <fdtdec.h>
+
+/**
+ * struct clk_ops - The functions that a clock driver must implement.
+ */
+struct clk_ops {
+	/**
+	 * of_xlate - Translate a client's device-tree (OF) clock specifier.
+	 *
+	 * The clock core calls this function as the first step in implementing
+	 * a client's clk_get_by_*() call.
+	 *
+	 * If this function pointer is set to NULL, the clock core will use a
+	 * default implementation, which assumes #clock-cells = <1>, and that
+	 * the DT cell contains a simple integer clock ID.
+	 *
+	 * At present, the clock API solely supports device-tree. If this
+	 * changes, other xxx_xlate() functions may be added to support those
+	 * other mechanisms.
+	 *
+	 * @clock:	The clock struct to hold the translation result.
+	 * @args:	The clock specifier values from device tree.
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*of_xlate)(struct clk *clock,
+			struct fdtdec_phandle_args *args);
+	/**
+	 * request - Request a translated clock.
+	 *
+	 * The clock core calls this function as the second step in
+	 * implementing a client's clk_get_by_*() call, following a successful
+	 * xxx_xlate() call, or as the only step in implementing a client's
+	 * clk_request() call.
+	 *
+	 * @clock:	The clock struct to request; this has been fille in by
+	 *		a previoux xxx_xlate() function call, or by the caller
+	 *		of clk_request().
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*request)(struct clk *clock);
+	/**
+	 * free - Free a previously requested clock.
+	 *
+	 * This is the implementation of the client clk_free() API.
+	 *
+	 * @clock:	The clock to free.
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*free)(struct clk *clock);
+	/**
+	 * get_rate() - Get current clock rate.
+	 *
+	 * @clk:	The clock to query.
+	 * @return clock rate in Hz, or -ve error code
+	 */
+	ulong (*get_rate)(struct clk *clk);
+	/**
+	 * set_rate() - Set current clock rate.
+	 *
+	 * @clk:	The clock to manipulate.
+	 * @rate:	New clock rate in Hz.
+	 * @return new rate, or -ve error code.
+	 */
+	ulong (*set_rate)(struct clk *clk, ulong rate);
+	/**
+	 * enable() - Enable a clock.
+	 *
+	 * @clk:	The clock to manipulate.
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*enable)(struct clk *clk);
+	/**
+	 * disable() - Disable a clock.
+	 *
+	 * @clk:	The clock to manipulate.
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*disable)(struct clk *clk);
+};
+
+#endif