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>

3 files changed, 127 insertions, 10 deletions

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index 879b30e3cc..9e46f9e815 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -108,8 +108,23 @@
 		compatible = "denx,u-boot-fdt-test";
 	};
 
-	clk@0 {
+	clk_fixed: clk-fixed {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <1234>;
+	};
+
+	clk_sandbox: clk-sbox {
 		compatible = "sandbox,clk";
+		#clock-cells = <1>;
+	};
+
+	clk-test {
+		compatible = "sandbox,clk-test";
+		clocks = <&clk_fixed>,
+			 <&clk_sandbox 1>,
+			 <&clk_sandbox 0>;
+		clock-names = "fixed", "i2c", "spi";
 	};
 
 	eth@10002000 {
diff --git a/arch/sandbox/include/asm/clk.h b/arch/sandbox/include/asm/clk.h
new file mode 100644
index 0000000000..9dc6c8184b
--- /dev/null
+++ b/arch/sandbox/include/asm/clk.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __SANDBOX_CLK_H
+#define __SANDBOX_CLK_H
+
+#include <common.h>
+
+struct udevice;
+
+/**
+ * enum sandbox_clk_id - Identity of clocks implemented by the sandbox clock
+ * provider.
+ *
+ * These IDs are within/relative-to the clock provider.
+ */
+enum sandbox_clk_id {
+	SANDBOX_CLK_ID_SPI,
+	SANDBOX_CLK_ID_I2C,
+
+	SANDBOX_CLK_ID_COUNT,
+};
+
+/**
+ * enum sandbox_clk_test_id - Identity of the clocks consumed by the sandbox
+ * clock test device.
+ *
+ * These are the IDs the clock consumer knows the clocks as.
+ */
+enum sandbox_clk_test_id {
+	SANDBOX_CLK_TEST_ID_FIXED,
+	SANDBOX_CLK_TEST_ID_SPI,
+	SANDBOX_CLK_TEST_ID_I2C,
+
+	SANDBOX_CLK_TEST_ID_COUNT,
+};
+
+/**
+ * sandbox_clk_query_rate - Query the current rate of a sandbox clock.
+ *
+ * @dev:	The sandbox clock provider device.
+ * @id:		The clock to query.
+ * @return:	The rate of the clock.
+ */
+ulong sandbox_clk_query_rate(struct udevice *dev, int id);
+/**
+ * sandbox_clk_query_enable - Query the enable state of a sandbox clock.
+ *
+ * @dev:	The sandbox clock provider device.
+ * @id:		The clock to query.
+ * @return:	The rate of the clock.
+ */
+int sandbox_clk_query_enable(struct udevice *dev, int id);
+
+/**
+ * sandbox_clk_test_get - Ask the sandbox clock test device to request its
+ * clocks.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @return:	0 if OK, or a negative error code.
+ */
+int sandbox_clk_test_get(struct udevice *dev);
+/**
+ * sandbox_clk_test_get_rate - Ask the sandbox clock test device to query a
+ * clock's rate.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @id:		The test device's clock ID to query.
+ * @return:	The rate of the clock.
+ */
+ulong sandbox_clk_test_get_rate(struct udevice *dev, int id);
+/**
+ * sandbox_clk_test_set_rate - Ask the sandbox clock test device to set a
+ * clock's rate.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @id:		The test device's clock ID to configure.
+ * @return:	The new rate of the clock.
+ */
+ulong sandbox_clk_test_set_rate(struct udevice *dev, int id, ulong rate);
+/**
+ * sandbox_clk_test_enable - Ask the sandbox clock test device to enable a
+ * clock.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @id:		The test device's clock ID to configure.
+ * @return:	0 if OK, or a negative error code.
+ */
+int sandbox_clk_test_enable(struct udevice *dev, int id);
+/**
+ * sandbox_clk_test_disable - Ask the sandbox clock test device to disable a
+ * clock.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @id:		The test device's clock ID to configure.
+ * @return:	0 if OK, or a negative error code.
+ */
+int sandbox_clk_test_disable(struct udevice *dev, int id);
+/**
+ * sandbox_clk_test_free - Ask the sandbox clock test device to free its
+ * clocks.
+ *
+ * @dev:	The sandbox clock test (client) devivce.
+ * @return:	0 if OK, or a negative error code.
+ */
+int sandbox_clk_test_free(struct udevice *dev);
+
+#endif
diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index 224b0ebaf9..451a78e590 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -19,15 +19,6 @@
 
 #define SANDBOX_CLK_RATE		32768
 
-enum {
-	PERIPH_ID_FIRST = 0,
-	PERIPH_ID_SPI = PERIPH_ID_FIRST,
-	PERIPH_ID_I2C,
-	PERIPH_ID_PCI,
-
-	PERIPH_ID_COUNT,
-};
-
 /* System controller driver data */
 enum {
 	SYSCON0		= 32,