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>

9 files changed, 204 insertions, 55 deletions

diff --git a/arch/arm/include/asm/arch-rockchip/clock.h b/arch/arm/include/asm/arch-rockchip/clock.h
index d66b26f18e..317e5128ed 100644
--- a/arch/arm/include/asm/arch-rockchip/clock.h
+++ b/arch/arm/include/asm/arch-rockchip/clock.h
@@ -62,18 +62,6 @@ static inline u32 clk_get_divisor(ulong input_rate, uint output_rate)
  */
 void *rockchip_get_cru(void);
 
-/**
- * rkclk_get_clk() - get a pointer to a given clock
- *
- * This is an internal function - use outside the clock subsystem indicates
- * that work is needed!
- *
- * @clk_id:	Clock requested
- * @devp:	Returns a pointer to that clock
- * @return 0 if OK, -ve on error
- */
-int rkclk_get_clk(enum rk_clk_id clk_id, struct udevice **devp);
-
 struct rk3288_cru;
 struct rk3288_grf;
 
diff --git a/arch/arm/mach-rockchip/board.c b/arch/arm/mach-rockchip/board.c
index 133d66341b..816540e582 100644
--- a/arch/arm/mach-rockchip/board.c
+++ b/arch/arm/mach-rockchip/board.c
@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <ram.h>
 #include <asm/io.h>
+#include <asm/arch/clock.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -54,15 +55,43 @@ void lowlevel_init(void)
 static int do_clock(cmd_tbl_t *cmdtp, int flag, int argc,
 		       char * const argv[])
 {
+	static const struct {
+		char *name;
+		int id;
+	} clks[] = {
+		{ "osc", CLK_OSC },
+		{ "apll", CLK_ARM },
+		{ "dpll", CLK_DDR },
+		{ "cpll", CLK_CODEC },
+		{ "gpll", CLK_GENERAL },
+#ifdef CONFIG_ROCKCHIP_RK3036
+		{ "mpll", CLK_NEW },
+#else
+		{ "npll", CLK_NEW },
+#endif
+	};
+	int ret, i;
 	struct udevice *dev;
 
-	for (uclass_first_device(UCLASS_CLK, &dev);
-	     dev;
-	     uclass_next_device(&dev)) {
+	ret = uclass_get_device(UCLASS_CLK, 0, &dev);
+	if (ret) {
+		printf("clk-uclass not found\n");
+		return 0;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(clks); i++) {
+		struct clk clk;
 		ulong rate;
 
-		rate = clk_get_rate(dev);
-		printf("%s: %lu\n", dev->name, rate);
+		clk.id = clks[i].id;
+		ret = clk_request(dev, &clk);
+		if (ret < 0)
+			continue;
+
+		rate = clk_get_rate(&clk);
+		printf("%s: %lu\n", clks[i].name, rate);
+
+		clk_free(&clk);
 	}
 
 	return 0;
diff --git a/arch/arm/mach-rockchip/rk3288/sdram_rk3288.c b/arch/arm/mach-rockchip/rk3288/sdram_rk3288.c
index 2e21282335..55ac73e9d2 100644
--- a/arch/arm/mach-rockchip/rk3288/sdram_rk3288.c
+++ b/arch/arm/mach-rockchip/rk3288/sdram_rk3288.c
@@ -36,7 +36,7 @@ struct chan_info {
 struct dram_info {
 	struct chan_info chan[2];
 	struct ram_info info;
-	struct udevice *ddr_clk;
+	struct clk ddr_clk;
 	struct rk3288_cru *cru;
 	struct rk3288_grf *grf;
 	struct rk3288_sgrf *sgrf;
@@ -576,7 +576,7 @@ static void dram_all_config(const struct dram_info *dram,
 	rk_clrsetreg(&dram->sgrf->soc_con2, 0x1f, sdram_params->base.stride);
 }
 
-static int sdram_init(const struct dram_info *dram,
+static int sdram_init(struct dram_info *dram,
 		      const struct rk3288_sdram_params *sdram_params)
 {
 	int channel;
@@ -592,8 +592,8 @@ static int sdram_init(const struct dram_info *dram,
 		return -E2BIG;
 	}
 
-	debug("ddr clk %s\n", dram->ddr_clk->name);
-	ret = clk_set_rate(dram->ddr_clk, sdram_params->base.ddr_freq);
+	debug("ddr clk dpll\n");
+	ret = clk_set_rate(&dram->ddr_clk, sdram_params->base.ddr_freq);
 	debug("ret=%d\n", ret);
 	if (ret) {
 		debug("Could not set DDR clock\n");
@@ -836,6 +836,7 @@ static int rk3288_dmc_probe(struct udevice *dev)
 	struct dram_info *priv = dev_get_priv(dev);
 	struct regmap *map;
 	int ret;
+	struct udevice *dev_clk;
 
 	map = syscon_get_regmap_by_driver_data(ROCKCHIP_SYSCON_NOC);
 	if (IS_ERR(map))
@@ -856,7 +857,11 @@ static int rk3288_dmc_probe(struct udevice *dev)
 	priv->chan[1].pctl = regmap_get_range(map, 2);
 	priv->chan[1].publ = regmap_get_range(map, 3);
 
-	ret = uclass_get_device(UCLASS_CLK, CLK_DDR, &priv->ddr_clk);
+	ret = uclass_get_device(UCLASS_CLK, 0, &dev_clk);
+	if (ret)
+		return ret;
+	priv->ddr_clk.id = CLK_DDR;
+	ret = clk_request(dev_clk, &priv->ddr_clk);
 	if (ret)
 		return ret;
 
diff --git a/arch/arm/mach-snapdragon/clock-apq8016.c b/arch/arm/mach-snapdragon/clock-apq8016.c
index d548d757d3..c2cf92494a 100644
--- a/arch/arm/mach-snapdragon/clock-apq8016.c
+++ b/arch/arm/mach-snapdragon/clock-apq8016.c
@@ -9,7 +9,7 @@
  */
 
 #include <common.h>
-#include <clk.h>
+#include <clk-uclass.h>
 #include <dm.h>
 #include <errno.h>
 #include <asm/io.h>
@@ -212,11 +212,11 @@ static int clk_init_uart(struct msm_clk_priv *priv)
 	return 0;
 }
 
-ulong msm_set_periph_rate(struct udevice *dev, int periph, ulong rate)
+ulong msm_set_rate(struct clk *clk, ulong rate)
 {
-	struct msm_clk_priv *priv = dev_get_priv(dev);
+	struct msm_clk_priv *priv = dev_get_priv(clk->dev);
 
-	switch (periph) {
+	switch (clk->id) {
 	case 0: /* SDC1 */
 		return clk_init_sdc(priv, 0, rate);
 		break;
@@ -243,7 +243,7 @@ static int msm_clk_probe(struct udevice *dev)
 }
 
 static struct clk_ops msm_clk_ops = {
-	.set_periph_rate = msm_set_periph_rate,
+	.set_rate = msm_set_rate,
 };
 
 static const struct udevice_id msm_clk_ids[] = {
diff --git a/arch/arm/mach-zynq/clk.c b/arch/arm/mach-zynq/clk.c
index 6444be8f03..40383c11c9 100644
--- a/arch/arm/mach-zynq/clk.c
+++ b/arch/arm/mach-zynq/clk.c
@@ -6,7 +6,6 @@
  */
 #include <common.h>
 #include <errno.h>
-#include <clk.h>
 #include <asm/io.h>
 #include <asm/arch/hardware.h>
 #include <asm/arch/clk.h>
diff --git a/arch/mips/mach-pic32/cpu.c b/arch/mips/mach-pic32/cpu.c
index f2ee911df4..ac33391921 100644
--- a/arch/mips/mach-pic32/cpu.c
+++ b/arch/mips/mach-pic32/cpu.c
@@ -23,18 +23,34 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-static ulong clk_get_cpu_rate(void)
+static ulong rate(int id)
 {
 	int ret;
 	struct udevice *dev;
+	struct clk clk;
+	ulong rate;
 
 	ret = uclass_get_device(UCLASS_CLK, 0, &dev);
 	if (ret) {
-		panic("uclass-clk: device not found\n");
+		printf("clk-uclass not found\n");
 		return 0;
 	}
 
-	return clk_get_rate(dev);
+	clk.id = id;
+	ret = clk_request(dev, &clk);
+	if (ret < 0)
+		return ret;
+
+	rate = clk_get_rate(&clk);
+
+	clk_free(&clk);
+
+	return rate;
+}
+
+static ulong clk_get_cpu_rate(void)
+{
+	return rate(PB7CLK);
 }
 
 /* initialize prefetch module related to cpu_clk */
@@ -127,30 +143,25 @@ const char *get_core_name(void)
 }
 #endif
 #ifdef CONFIG_CMD_CLK
+
 int soc_clk_dump(void)
 {
-	int i, ret;
-	struct udevice *dev;
-
-	ret = uclass_get_device(UCLASS_CLK, 0, &dev);
-	if (ret) {
-		printf("clk-uclass not found\n");
-		return ret;
-	}
+	int i;
 
 	printf("PLL Speed: %lu MHz\n",
-	       CLK_MHZ(clk_get_periph_rate(dev, PLLCLK)));
-	printf("CPU Speed: %lu MHz\n", CLK_MHZ(clk_get_rate(dev)));
-	printf("MPLL Speed: %lu MHz\n",
-	       CLK_MHZ(clk_get_periph_rate(dev, MPLL)));
+	       CLK_MHZ(rate(PLLCLK)));
+
+	printf("CPU Speed: %lu MHz\n", CLK_MHZ(rate(PB7CLK)));
+
+	printf("MPLL Speed: %lu MHz\n", CLK_MHZ(rate(MPLL)));
 
 	for (i = PB1CLK; i <= PB7CLK; i++)
 		printf("PB%d Clock Speed: %lu MHz\n", i - PB1CLK + 1,
-		       CLK_MHZ(clk_get_periph_rate(dev, i)));
+		       CLK_MHZ(rate(i)));
 
 	for (i = REF1CLK; i <= REF5CLK; i++)
 		printf("REFO%d Clock Speed: %lu MHz\n", i - REF1CLK + 1,
-		       CLK_MHZ(clk_get_periph_rate(dev, i)));
+		       CLK_MHZ(rate(i)));
 	return 0;
 }
 #endif
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,