Merge tag 'clk-2022.04-rc2' of https://source.denx.de/u-boot/custodians/u-boot-clk

Clock patches for v2022.04-rc2

This has an assortment of cleanups and the occasional bugfix. Also present
is the addition of the clock subsystem documentation to HTML docs.

CI: https://source.denx.de/u-boot/custodians/u-boot-clk/-/pipelines/11075

cmd/clk.c

@@ -99,20 +99,6 @@ static int do_clk_dump(struct cmd_tbl *cmdtp, int flag, int argc,
 }
 
 #if CONFIG_IS_ENABLED(DM) && CONFIG_IS_ENABLED(CLK)
-struct udevice *clk_lookup(const char *name)
-{
-	int i = 0;
-	struct udevice *dev;
-
-	do {
-		uclass_get_device(UCLASS_CLK, i++, &dev);
-		if (!strcmp(name, dev->name))
-			return dev;
-	} while (dev);
-
-	return NULL;
-}
-
 static int do_clk_setfreq(struct cmd_tbl *cmdtp, int flag, int argc,
 			  char *const argv[])
 {
@@ -120,16 +106,17 @@ static int do_clk_setfreq(struct cmd_tbl *cmdtp, int flag, int argc,
 	s32 freq;
 	struct udevice *dev;
 
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
 	freq = dectoul(argv[2], NULL);
 
-	dev = clk_lookup(argv[1]);
+	if (!uclass_get_device_by_name(UCLASS_CLK, argv[1], &dev))
-
-	if (dev)
 		clk = dev_get_clk_ptr(dev);
 
 	if (!clk) {
 		printf("clock '%s' not found.\n", argv[1]);
-		return -EINVAL;
+		return CMD_RET_FAILURE;
 	}
 
 	freq = clk_set_rate(clk, freq);
@@ -173,7 +160,7 @@ static int do_clk(struct cmd_tbl *cmdtp, int flag, int argc,
 #ifdef CONFIG_SYS_LONGHELP
 static char clk_help_text[] =
 	"dump - Print clock frequencies\n"
-	"setfreq [clk] [freq] - Set clock frequency";
+	"clk setfreq [clk] [freq] - Set clock frequency";
 #endif
 
 U_BOOT_CMD(clk, 4, 1, do_clk, "CLK sub-system", clk_help_text);

configs/gazerbeam_defconfig

@@ -157,7 +157,7 @@ CONFIG_REGMAP=y
 CONFIG_AXI=y
 CONFIG_IHS_AXI=y
 CONFIG_CLK=y
-CONFIG_ICS8N3QV01=y
+CONFIG_CLK_ICS8N3QV01=y
 CONFIG_CPU=y
 CONFIG_CPU_MPC83XX=y
 CONFIG_SYS_BR0_PRELIM_BOOL=y

doc/api/clk.rst

@@ -0,0 +1,19 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Clock API
+=========
+
+.. kernel-doc:: include/clk.h
+   :doc: Overview
+
+Client API
+----------
+
+.. kernel-doc:: include/clk.h
+   :internal:
+
+Driver API
+----------
+
+.. kernel-doc:: include/clk-uclass.h
+   :internal:

doc/api/index.rst

@@ -6,6 +6,7 @@ U-Boot API documentation
 .. toctree::
    :maxdepth: 2
 
+   clk
    dfu
    dm
    efi

drivers/clk/Kconfig

@@ -30,22 +30,6 @@ config TPL_CLK
 	  setting up clocks within TPL, and allows the same drivers to be
 	  used as U-Boot proper.
 
-config CLK_BCM6345
-	bool "Clock controller driver for BCM6345"
-	depends on CLK && ARCH_BMIPS
-	default y
-	help
-	  This clock driver adds support for enabling and disabling peripheral
-	  clocks on BCM6345 SoCs. HW has no rate changing capabilities.
-
-config CLK_BOSTON
-	def_bool y if TARGET_BOSTON
-	depends on CLK
-	select REGMAP
-	select SYSCON
-	help
-	  Enable this to support the clocks
-
 config SPL_CLK_CCF
 	bool "SPL Common Clock Framework [CCF] support "
 	depends on SPL
@@ -73,6 +57,37 @@ config CLK_COMPOSITE_CCF
 	  Enable this option if you want to (re-)use the Linux kernel's Common
 	  Clock Framework [CCF] composite code in U-Boot's clock driver.
 
+config CLK_BCM6345
+	bool "Clock controller driver for BCM6345"
+	depends on CLK && ARCH_BMIPS
+	default y
+	help
+	  This clock driver adds support for enabling and disabling peripheral
+	  clocks on BCM6345 SoCs. HW has no rate changing capabilities.
+
+config CLK_BOSTON
+	def_bool y if TARGET_BOSTON
+	depends on CLK
+	select REGMAP
+	select SYSCON
+	help
+	  Enable this to support the clocks
+
+config CLK_CDCE9XX
+	bool "Enable CDCD9XX clock driver"
+	depends on CLK
+	help
+	   Enable the clock synthesizer driver for CDCE913/925/937/949
+	   series of chips.
+
+config CLK_ICS8N3QV01
+	bool "Enable ICS8N3QV01 VCXO driver"
+	depends on CLK
+	help
+	  Support for the ICS8N3QV01 Quad-Frequency VCXO (Voltage-Controlled
+	  Crystal Oscillator). The output frequency can be programmed via an
+	  I2C interface.
+
 config CLK_INTEL
 	bool "Enable clock driver for Intel x86"
 	depends on CLK && X86
@@ -83,6 +98,25 @@ config CLK_INTEL
 	  set up by U-Boot itself but only statically. Thus the driver does not
 	  support changing clock rates, only querying them.
 
+config CLK_K210
+	bool "Clock support for Kendryte K210"
+	depends on CLK
+	help
+	  This enables support clock driver for Kendryte K210 platforms.
+
+config CLK_K210_SET_RATE
+	bool "Enable setting the Kendryte K210 PLL rate"
+	depends on CLK_K210
+	help
+	  Add functionality to calculate new rates for K210 PLLs. Enabling this
+	  feature adds around 1K to U-Boot's final size.
+
+config CLK_MPC83XX
+	bool "Enable MPC83xx clock driver"
+	depends on CLK
+	help
+	  Support for the clock driver of the MPC83xx series of SoCs.
+
 config CLK_OCTEON
 	bool "Clock controller driver for Marvell MIPS Octeon"
 	depends on CLK && ARCH_OCTEON
@@ -90,6 +124,22 @@ config CLK_OCTEON
 	help
 	  Enable this to support the clocks on Octeon MIPS platforms.
 
+config SANDBOX_CLK_CCF
+	bool "Sandbox Common Clock Framework [CCF] support "
+	depends on SANDBOX
+	select CLK_CCF
+	help
+	  Enable this option if you want to test the Linux kernel's Common
+	  Clock Framework [CCF] code in U-Boot's Sandbox clock driver.
+
+config CLK_SCMI
+	bool "Enable SCMI clock driver"
+	depends on SCMI_FIRMWARE
+	help
+	  Enable this option if you want to support clock devices exposed
+	  by a SCMI agent based on SCMI clock protocol communication
+	  with a SCMI server.
+
 config CLK_STM32F
 	bool "Enable clock driver support for STM32F family"
 	depends on CLK && (STM32F7 || STM32F4)
@@ -98,6 +148,14 @@ config CLK_STM32F
 	  This clock driver adds support for RCC clock management
 	  for STM32F4 and STM32F7 SoCs.
 
+config CLK_STM32MP1
+	bool "Enable RCC clock driver for STM32MP1"
+	depends on ARCH_STM32MP && CLK
+	default y
+	help
+	  Enable the STM32 clock (RCC) driver. Enable support for
+	  manipulating STM32MP1's on-SoC clocks.
+
 config CLK_HSDK
 	bool "Enable cgu clock driver for HSDK boards"
 	depends on CLK && TARGET_HSDK
@@ -105,6 +163,15 @@ config CLK_HSDK
 	  Enable this to support the cgu clocks on Synopsys ARC HSDK and
 	  Synopsys ARC HSDK-4xD boards
 
+config CLK_VERSACLOCK
+	tristate "Enable VersaClock 5/6 devices"
+	depends on CLK
+	depends on CLK_CCF
+	depends on OF_CONTROL
+	help
+	  This driver supports the IDT VersaClock 5 and VersaClock 6
+	  programmable clock generators.
+
 config CLK_VERSAL
 	bool "Enable clock driver support for Versal"
 	depends on ARCH_VERSAL
@@ -120,14 +187,6 @@ config CLK_VEXPRESS_OSC
 	  This clock driver adds support for clock generators present on
 	  Arm Versatile Express platforms.
 
-config CLK_ZYNQ
-	bool "Enable clock driver support for Zynq"
-	depends on CLK && ARCH_ZYNQ
-	default y
-	help
-	  This clock driver adds support for clock related settings for
-	  Zynq platform.
-
 config CLK_XLNX_CLKWZRD
 	bool "Xilinx Clocking Wizard"
 	depends on CLK
@@ -139,6 +198,14 @@ config CLK_XLNX_CLKWZRD
 	  set_duty_cycle API, this driver only supports set_rate to modify
 	  the frequency.
 
+config CLK_ZYNQ
+	bool "Enable clock driver support for Zynq"
+	depends on CLK && ARCH_ZYNQ
+	default y
+	help
+	  This clock driver adds support for clock related settings for
+	  Zynq platform.
+
 config CLK_ZYNQMP
 	bool "Enable clock driver support for ZynqMP"
 	depends on ARCH_ZYNQMP
@@ -147,42 +214,6 @@ config CLK_ZYNQMP
 	  This clock driver adds support for clock realted settings for
 	  ZynqMP platform.
 
-config CLK_STM32MP1
-	bool "Enable RCC clock driver for STM32MP1"
-	depends on ARCH_STM32MP && CLK
-	default y
-	help
-	  Enable the STM32 clock (RCC) driver. Enable support for
-	  manipulating STM32MP1's on-SoC clocks.
-
-config CLK_CDCE9XX
-	bool "Enable CDCD9XX clock driver"
-	depends on CLK
-	help
-	   Enable the clock synthesizer driver for CDCE913/925/937/949
-	   series of chips.
-
-config CLK_SCMI
-	bool "Enable SCMI clock driver"
-	depends on SCMI_FIRMWARE
-	help
-	  Enable this option if you want to support clock devices exposed
-	  by a SCMI agent based on SCMI clock protocol communication
-	  with a SCMI server.
-
-config CLK_K210
-	bool "Clock support for Kendryte K210"
-	depends on CLK
-	help
-	  This enables support clock driver for Kendryte K210 platforms.
-
-config CLK_K210_SET_RATE
-	bool "Enable setting the Kendryte K210 PLL rate"
-	depends on CLK_K210
-	help
-	  Add functionality to calculate new rates for K210 PLLs. Enabling this
-	  feature adds around 1K to U-Boot's final size.
-
 source "drivers/clk/analogbits/Kconfig"
 source "drivers/clk/at91/Kconfig"
 source "drivers/clk/exynos/Kconfig"
@@ -198,35 +229,4 @@ source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/ti/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
 
-config ICS8N3QV01
-	bool "Enable ICS8N3QV01 VCXO driver"
-	depends on CLK
-	help
-	  Support for the ICS8N3QV01 Quad-Frequency VCXO (Voltage-Controlled
-	  Crystal Oscillator). The output frequency can be programmed via an
-	  I2C interface.
-
-config CLK_MPC83XX
-	bool "Enable MPC83xx clock driver"
-	depends on CLK
-	help
-	  Support for the clock driver of the MPC83xx series of SoCs.
-
-config SANDBOX_CLK_CCF
-	bool "Sandbox Common Clock Framework [CCF] support "
-	depends on SANDBOX
-	select CLK_CCF
-	help
-	  Enable this option if you want to test the Linux kernel's Common
-	  Clock Framework [CCF] code in U-Boot's Sandbox clock driver.
-
-config CLK_VERSACLOCK
-	tristate "Enable VersaClock 5/6 devices"
-	depends on CLK
-	depends on CLK_CCF
-	depends on OF_CONTROL
-	help
-	  This driver supports the IDT VersaClock 5 and VersaClock 6
-	  programmable clock generators.
-
 endmenu

drivers/clk/Makefile

@@ -15,41 +15,41 @@ obj-y += analogbits/
 obj-y += imx/
 obj-y += tegra/
 obj-y += ti/
+obj-$(CONFIG_$(SPL_TPL_)CLK_INTEL) += intel/
 obj-$(CONFIG_ARCH_ASPEED) += aspeed/
 obj-$(CONFIG_ARCH_MEDIATEK) += mediatek/
-obj-$(CONFIG_ARCH_MTMIPS) += mtmips/
 obj-$(CONFIG_ARCH_MESON) += meson/
+obj-$(CONFIG_ARCH_MTMIPS) += mtmips/
 obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
 obj-$(CONFIG_ARCH_SOCFPGA) += altera/
+obj-$(CONFIG_ARCH_SUNXI) += sunxi/
 obj-$(CONFIG_CLK_AT91) += at91/
-obj-$(CONFIG_CLK_MVEBU) += mvebu/
 obj-$(CONFIG_CLK_BCM6345) += clk_bcm6345.o
 obj-$(CONFIG_CLK_BOSTON) += clk_boston.o
+obj-$(CONFIG_CLK_CDCE9XX) += clk-cdce9xx.o
 obj-$(CONFIG_CLK_EXYNOS) += exynos/
-obj-$(CONFIG_$(SPL_TPL_)CLK_INTEL) += intel/
 obj-$(CONFIG_CLK_HSDK) += clk-hsdk-cgu.o
 obj-$(CONFIG_CLK_K210) += clk_kendryte.o
 obj-$(CONFIG_CLK_MPC83XX) += mpc83xx_clk.o
 obj-$(CONFIG_CLK_MPFS) += microchip/
+obj-$(CONFIG_CLK_MVEBU) += mvebu/
 obj-$(CONFIG_CLK_OCTEON) += clk_octeon.o
 obj-$(CONFIG_CLK_OWL) += owl/
 obj-$(CONFIG_CLK_RENESAS) += renesas/
 obj-$(CONFIG_CLK_SCMI) += clk_scmi.o
 obj-$(CONFIG_CLK_SIFIVE) += sifive/
-obj-$(CONFIG_ARCH_SUNXI) += sunxi/
 obj-$(CONFIG_CLK_STM32F) += clk_stm32f.o
 obj-$(CONFIG_CLK_STM32MP1) += clk_stm32mp1.o
 obj-$(CONFIG_CLK_UNIPHIER) += uniphier/
+obj-$(CONFIG_CLK_VERSACLOCK) += clk_versaclock.o
+obj-$(CONFIG_CLK_VERSAL) += clk_versal.o
 obj-$(CONFIG_CLK_VEXPRESS_OSC) += clk_vexpress_osc.o
+obj-$(CONFIG_CLK_XLNX_CLKWZRD) += clk-xlnx-clock-wizard.o
 obj-$(CONFIG_CLK_ZYNQ) += clk_zynq.o
 obj-$(CONFIG_CLK_ZYNQMP) += clk_zynqmp.o
-obj-$(CONFIG_CLK_XLNX_CLKWZRD) += clk-xlnx-clock-wizard.o
+obj-$(CONFIG_CLK_ICS8N3QV01) += ics8n3qv01.o
-obj-$(CONFIG_ICS8N3QV01) += ics8n3qv01.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
+obj-$(CONFIG_SANDBOX_CLK_CCF) += clk_sandbox_ccf.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
-obj-$(CONFIG_SANDBOX_CLK_CCF) += clk_sandbox_ccf.o
 obj-$(CONFIG_STM32H7) += clk_stm32h7.o
-obj-$(CONFIG_CLK_VERSAL) += clk_versal.o
-obj-$(CONFIG_CLK_CDCE9XX) += clk-cdce9xx.o
-obj-$(CONFIG_CLK_VERSACLOCK) += clk_versaclock.o

drivers/clk/clk-cdce9xx.c

@@ -86,19 +86,13 @@ static int cdce9xx_reg_write(struct udevice *dev, u8 addr, u8 val)
 	return ret;
 }
 
-static int cdce9xx_clk_of_xlate(struct clk *clk,
+static int cdce9xx_clk_request(struct clk *clk)
-				struct ofnode_phandle_args *args)
 {
 	struct cdce9xx_clk_data *data = dev_get_priv(clk->dev);
 
-	if (args->args_count != 1)
+	if (clk->id > data->chip->num_outputs)
 		return -EINVAL;
 
-	if (args->args[0] > data->chip->num_outputs)
-		return -EINVAL;
-
-	clk->id = args->args[0];
-
 	return 0;
 }
 
@@ -241,7 +235,7 @@ static const struct udevice_id cdce9xx_clk_of_match[] = {
 };
 
 static const struct clk_ops cdce9xx_clk_ops = {
-	.of_xlate = cdce9xx_clk_of_xlate,
+	.request = cdce9xx_clk_request,
 	.get_rate = cdce9xx_clk_get_rate,
 	.set_rate = cdce9xx_clk_set_rate,
 };

drivers/clk/clk-uclass.c

@@ -432,17 +432,6 @@ int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk)
 	return clk_get_by_index_nodev(node, index, clk);
 }
 
-int clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk)
-{
-	int ret;
-
-	ret = clk_get_by_name_nodev(node, name, clk);
-	if (ret == -ENODATA)
-		return 0;
-
-	return ret;
-}
-
 int clk_release_all(struct clk *clk, int count)
 {
 	int i, ret;
@@ -652,7 +641,7 @@ int clk_enable(struct clk *clk)
 				return 0;
 			}
 			if (clkp->dev->parent &&
-			    device_get_uclass_id(clkp->dev) == UCLASS_CLK) {
+			    device_get_uclass_id(clkp->dev->parent) == UCLASS_CLK) {
 				ret = clk_enable(dev_get_clk_ptr(clkp->dev->parent));
 				if (ret) {
 					printf("Enable %s failed\n",
@@ -726,7 +715,7 @@ int clk_disable(struct clk *clk)
 		}
 
 		if (clkp && clkp->dev->parent &&
-		    device_get_uclass_id(clkp->dev) == UCLASS_CLK) {
+		    device_get_uclass_id(clkp->dev->parent) == UCLASS_CLK) {
 			ret = clk_disable(dev_get_clk_ptr(clkp->dev->parent));
 			if (ret) {
 				printf("Disable %s failed\n",
@@ -823,16 +812,6 @@ struct clk *devm_clk_get(struct udevice *dev, const char *id)
 	return clk;
 }
 
-struct clk *devm_clk_get_optional(struct udevice *dev, const char *id)
-{
-	struct clk *clk = devm_clk_get(dev, id);
-
-	if (PTR_ERR(clk) == -ENODATA)
-		return NULL;
-
-	return clk;
-}
-
 void devm_clk_put(struct udevice *dev, struct clk *clk)
 {
 	int rc;

drivers/clk/clk_versaclock.c

@@ -618,24 +618,6 @@ static int vc5_clk_out_set_parent(struct vc5_driver_data *vc, u8 num, u8 index)
 	return vc5_update_bits(vc->i2c, VC5_OUT_DIV_CONTROL(num), mask, src);
 }
 
-/*
- * The device references to the Versaclock point to the head, so xlate needs to
- * redirect it to clk_out[idx]
- */
-static int vc5_clk_out_xlate(struct clk *hw, struct ofnode_phandle_args *args)
-{
-	unsigned int idx = args->args[0];
-
-	if (args->args_count != 1) {
-		debug("Invalid args_count: %d\n", args->args_count);
-		return -EINVAL;
-	}
-
-	hw->id = idx;
-
-	return 0;
-}
-
 static unsigned long vc5_clk_out_set_rate(struct clk *hw, unsigned long rate)
 {
 	struct udevice *dev;
@@ -671,7 +653,6 @@ static const struct clk_ops vc5_clk_out_sel_ops = {
 static const struct clk_ops vc5_clk_ops = {
 	.enable	= vc5_clk_out_prepare,
 	.disable	= vc5_clk_out_unprepare,
-	.of_xlate	= vc5_clk_out_xlate,
 	.set_rate	= vc5_clk_out_set_rate,
 	.get_rate	= vc5_clk_out_get_rate,
 };

drivers/clk/clk_zynq.c

@@ -472,8 +472,9 @@ static int zynq_clk_probe(struct udevice *dev)
 
 	for (i = 0; i < 2; i++) {
 		sprintf(name, "gem%d_emio_clk", i);
-		ret = clk_get_by_name(dev, name, &priv->gem_emio_clk[i]);
+		ret = clk_get_by_name_optional(dev, name,
-		if (ret < 0 && ret != -ENODATA) {
+					       &priv->gem_emio_clk[i]);
+		if (ret) {
 			dev_err(dev, "failed to get %s clock\n", name);
 			return ret;
 		}

drivers/clk/ics8n3qv01.c

@@ -180,11 +180,6 @@ static ulong ics8n3qv01_set_rate(struct clk *clk, ulong fout)
 	return 0;
 }
 
-static int ics8n3qv01_request(struct clk *clock)
-{
-	return 0;
-}
-
 static ulong ics8n3qv01_get_rate(struct clk *clk)
 {
 	struct ics8n3qv01_priv *priv = dev_get_priv(clk->dev);
@@ -203,7 +198,6 @@ static int ics8n3qv01_disable(struct clk *clk)
 }
 
 static const struct clk_ops ics8n3qv01_ops = {
-	.request = ics8n3qv01_request,
 	.get_rate = ics8n3qv01_get_rate,
 	.set_rate = ics8n3qv01_set_rate,
 	.enable = ics8n3qv01_enable,

drivers/clk/tegra/tegra-car-clk.c

@@ -30,14 +30,6 @@ static int tegra_car_clk_request(struct clk *clk)
 	return 0;
 }
 
-static int tegra_car_clk_free(struct clk *clk)
-{
-	debug("%s(clk=%p) (dev=%p, id=%lu)\n", __func__, clk, clk->dev,
-	      clk->id);
-
-	return 0;
-}
-
 static ulong tegra_car_clk_get_rate(struct clk *clk)
 {
 	enum clock_id parent;
@@ -82,7 +74,6 @@ static int tegra_car_clk_disable(struct clk *clk)
 
 static struct clk_ops tegra_car_clk_ops = {
 	.request = tegra_car_clk_request,
-	.rfree = tegra_car_clk_free,
 	.get_rate = tegra_car_clk_get_rate,
 	.set_rate = tegra_car_clk_set_rate,
 	.enable = tegra_car_clk_enable,

drivers/clk/ti/clk-sci.c

@@ -64,18 +64,6 @@ static int ti_sci_clk_of_xlate(struct clk *clk,
 	return 0;
 }
 
-static int ti_sci_clk_request(struct clk *clk)
-{
-	debug("%s(clk=%p)\n", __func__, clk);
-	return 0;
-}
-
-static int ti_sci_clk_free(struct clk *clk)
-{
-	debug("%s(clk=%p)\n", __func__, clk);
-	return 0;
-}
-
 static ulong ti_sci_clk_get_rate(struct clk *clk)
 {
 	struct ti_sci_clk_data *data = dev_get_priv(clk->dev);
@@ -208,8 +196,6 @@ static const struct udevice_id ti_sci_clk_of_match[] = {
 
 static struct clk_ops ti_sci_clk_ops = {
 	.of_xlate = ti_sci_clk_of_xlate,
-	.request = ti_sci_clk_request,
-	.rfree = ti_sci_clk_free,
 	.get_rate = ti_sci_clk_get_rate,
 	.set_rate = ti_sci_clk_set_rate,
 	.set_parent = ti_sci_clk_set_parent,

drivers/phy/phy-mtk-tphy.c

@@ -723,13 +723,13 @@ static int mtk_tphy_probe(struct udevice *dev)
 		tphy->phys[index] = instance;
 		index++;
 
-		err = clk_get_optional_nodev(subnode, "ref",
+		err = clk_get_by_name_nodev_optional(subnode, "ref",
-					     &instance->ref_clk);
+						     &instance->ref_clk);
 		if (err)
 			return err;
 
-		err = clk_get_optional_nodev(subnode, "da_ref",
+		err = clk_get_by_name_nodev_optional(subnode, "da_ref",
-					     &instance->da_ref_clk);
+						     &instance->da_ref_clk);
 		if (err)
 			return err;
 	}

drivers/rng/meson-rng.c

@@ -91,8 +91,8 @@ static int meson_rng_of_to_plat(struct udevice *dev)
 		return -ENODEV;
 
 	/* Get optional "core" clock */
-	err = clk_get_by_name(dev, "core", &pdata->clk);
+	err = clk_get_by_name_optional(dev, "core", &pdata->clk);
-	if (err && err != -ENODATA)
+	if (err)
 		return err;
 
 	return 0;

include/clk-uclass.h

@@ -16,96 +16,127 @@ struct ofnode_phandle_args;
 
 /**
  * struct clk_ops - The functions that a clock driver must implement.
+ * @of_xlate: Translate a client's device-tree (OF) clock specifier.
+ * @request: Request a translated clock.
+ * @rfree: Free a previously requested clock.
+ * @round_rate: Adjust a rate to the exact rate a clock can provide.
+ * @get_rate: Get current clock rate.
+ * @set_rate: Set current clock rate.
+ * @set_parent: Set current clock parent
+ * @enable: Enable a clock.
+ * @disable: Disable a clock.
+ *
+ * The individual methods are described more fully below.
  */
 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 ofnode_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);
-	/**
-	 * rfree - 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 (*rfree)(struct clk *clock);
-	/**
-	 * round_rate() - Adjust a rate to the exact rate a clock can provide.
-	 *
-	 * @clk:	The clock to manipulate.
-	 * @rate:	Desidered clock rate in Hz.
-	 * @return rounded rate in Hz, or -ve error code.
-	 */
 	ulong (*round_rate)(struct clk *clk, ulong rate);
-	/**
-	 * 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);
-	/**
-	 * set_parent() - Set current clock parent
-	 *
-	 * @clk:        The clock to manipulate.
-	 * @parent:     New clock parent.
-	 * @return zero on success, or -ve error code.
-	 */
 	int (*set_parent)(struct clk *clk, struct clk *parent);
-	/**
-	 * 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);
 };
 
+#if 0 /* For documentation only */
+/**
+ * of_xlate() - Translate a client's device-tree (OF) clock specifier.
+ * @clock:	The clock struct to hold the translation result.
+ * @args:	The clock specifier values from device tree.
+ *
+ * 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.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+int of_xlate(struct clk *clock, struct ofnode_phandle_args *args);
+
+/**
+ * request() - Request a translated clock.
+ * @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().
+ *
+ * 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.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+int request(struct clk *clock);
+
+/**
+ * rfree() - Free a previously requested clock.
+ * @clock:	The clock to free.
+ *
+ * This is the implementation of the client clk_free() API.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+int rfree(struct clk *clock);
+
+/**
+ * round_rate() - Adjust a rate to the exact rate a clock can provide.
+ * @clk:	The clock to manipulate.
+ * @rate:	Desidered clock rate in Hz.
+ *
+ * Return: rounded rate in Hz, or -ve error code.
+ */
+ulong round_rate(struct clk *clk, ulong rate);
+
+/**
+ * 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);
+
+/**
+ * set_parent() - Set current clock parent
+ * @clk:        The clock to manipulate.
+ * @parent:     New clock parent.
+ *
+ * Return: zero on success, or -ve error code.
+ */
+int set_parent(struct clk *clk, struct clk *parent);
+
+/**
+ * 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
+
 #endif

include/clk.h

@@ -14,6 +14,8 @@
 #include <linux/types.h>
 
 /**
+ * DOC: Overview
+ *
  * 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
@@ -34,22 +36,22 @@ struct udevice;
 
 /**
  * struct clk - A handle to (allowing control of) a single clock.
+ * @dev: The device which implements the clock signal.
+ * @rate: The clock rate (in HZ).
+ * @flags: Flags used across common clock structure (e.g. %CLK_)
+ *         Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined
+ *         in struct's for those devices (e.g. &struct clk_mux).
+ * @enable_count: The number of times this clock has been enabled.
+ * @id: The clock signal ID within the provider.
+ * @data: An optional data field for scenarios where a single integer ID is not
+ *	  sufficient. If used, it can be populated through an .of_xlate op and
+ *	  processed during the various clock ops.
  *
  * 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.
- * @rate: The clock rate (in HZ).
- * @flags: Flags used across common clock structure (e.g. CLK_)
- *         Clock IP blocks specific flags (i.e. mux, div, gate, etc) are defined
- *         in struct's for those devices (e.g. struct clk_mux).
- * @id: The clock signal ID within the provider.
- * @data: An optional data field for scenarios where a single integer ID is not
- *	  sufficient. If used, it can be populated through an .of_xlate op and
- *	  processed during the various clock ops.
- *
  * Should additional information to identify and configure any clock signal
  * for any provider be required in the future, the struct could be expanded to
  * either (a) add more fields to allow clock providers to store additional
@@ -72,15 +74,14 @@ struct clk {
 
 /**
  * struct clk_bulk - A handle to (allowing control of) a bulk of clocks.
+ * @clks: An array of clock handles.
+ * @count: The number of clock handles in the clks array.
  *
  * Clients provide storage for the clock bulk. The content of the structure is
  * managed solely by the clock API. A clock bulk struct is
  * initialized by "get"ing the clock bulk struct.
  * The clock bulk struct is passed to all other bulk clock APIs to apply
  * the API to all the clock in the bulk struct.
- *
- * @clks: An array of clock handles.
- * @count: The number of clock handles in the clks array.
  */
 struct clk_bulk {
 	struct clk *clks;
@@ -91,16 +92,19 @@ struct clk_bulk {
 struct phandle_1_arg;
 /**
  * clk_get_by_phandle() - Get a clock by its phandle information (of-platadata)
+ * @dev: Device containing the phandle
+ * @cells: Phandle info
+ * @clk: A pointer to a clock struct to initialise
  *
  * This function is used when of-platdata is enabled.
  *
  * This looks up a clock using the phandle info. With dtoc, each phandle in the
- * 'clocks' property is transformed into an idx representing the device. For
+ * 'clocks' property is transformed into an idx representing the device.
- * example:
+ * For example::
  *
  *	clocks = <&dpll_mpu_ck 23>;
  *
- * might result in:
+ * might result in::
  *
  *	.clocks = {1, {23}},},
  *
@@ -109,9 +113,6 @@ struct phandle_1_arg;
  * this example it would return a clock containing the 'dpll_mpu_ck' device and
  * the clock ID 23.
  *
- * @dev: Device containing the phandle
- * @cells: Phandle info
- * @clock: A pointer to a clock struct to initialise
  * Return: 0 if OK, or a negative error code.
  */
 int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
@@ -119,6 +120,10 @@ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
 
 /**
  * clk_get_by_index() - Get/request a clock by integer index.
+ * @dev:	The client device.
+ * @index:	The index of the clock to request, within the client's list of
+ *		clocks.
+ * @clk:	A pointer to a clock struct to initialize.
  *
  * 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,
@@ -126,30 +131,26 @@ int clk_get_by_phandle(struct udevice *dev, const struct phandle_1_arg *cells,
  * 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_by_index_nodev - Get/request a clock by integer index
+ * clk_get_by_index_nodev() - Get/request a clock by integer index without a
- * without a device.
+ *                            device.
- *
- * This is a version of clk_get_by_index() that does not use a device.
- *
  * @node:	The client ofnode.
  * @index:	The index of the clock to request, within the client's list of
  *		clocks.
- * @clock	A pointer to a clock struct to initialize.
+ * @clk:	A pointer to a clock struct to initialize.
+ *
  * Return: 0 if OK, or a negative error code.
  */
 int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
 
 /**
- * clk_get_bulk - Get/request all clocks of a device.
+ * clk_get_bulk() - Get/request all clocks of a device.
+ * @dev:	The client device.
+ * @bulk:	A pointer to a clock bulk struct to initialize.
  *
  * This looks up and requests all clocks of the client device; each device is
  * assumed to have n clocks associated with it somehow, and this function finds
@@ -157,14 +158,16 @@ int clk_get_by_index_nodev(ofnode node, int index, struct clk *clk);
  * device clock indices to provider clocks may be via device-tree properties,
  * board-provided mapping tables, or some other mechanism.
  *
- * @dev:	The client device.
- * @bulk	A pointer to a clock bulk struct to initialize.
  * Return: 0 if OK, or a negative error code.
  */
 int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
 
 /**
- * clk_get_by_name - Get/request a clock by name.
+ * clk_get_by_name() - Get/request a clock by name.
+ * @dev:	The client device.
+ * @name:	The name of the clock to request, within the client's list of
+ *		clocks.
+ * @clk:	A pointer to a clock struct to initialize.
  *
  * 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,
@@ -172,83 +175,71 @@ int clk_get_bulk(struct udevice *dev, struct clk_bulk *bulk);
  * 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.
  */
 int clk_get_by_name(struct udevice *dev, const char *name, struct clk *clk);
 
 /**
  * clk_get_by_name_nodev - Get/request a clock by name without a device.
- *
- * This is a version of clk_get_by_name() that does not use a device.
- *
  * @node:	The client ofnode.
  * @name:	The name of the clock to request, within the client's list of
  *		clocks.
- * @clock:	A pointer to a clock struct to initialize.
+ * @clk:	A pointer to a clock struct to initialize.
+ *
  * Return: 0 if OK, or a negative error code.
  */
 int clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk);
 
 /**
- * clk_get_optional_nodev - Get/request an optinonal clock by name
+ * devm_clk_get() - lookup and obtain a managed reference to a clock producer.
- *		without a device.
- * @node:	The client ofnode.
- * @name:	The name of the clock to request.
- * @name:	The name of the clock to request, within the client's list of
- *		clocks.
- * @clock:	A pointer to a clock struct to initialize.
- *
- * Behaves the same as clk_get_by_name_nodev() except where there is
- * no clock producer, in this case, skip the error number -ENODATA, and
- * the function returns 0.
- */
-int clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk);
-
-/**
- * devm_clk_get - lookup and obtain a managed reference to a clock producer.
  * @dev: device for clock "consumer"
  * @id: clock consumer ID
  *
- * Returns a struct clk corresponding to the clock producer, or
+ * The implementation uses @dev and @id to determine the clock consumer, and
- * valid IS_ERR() condition containing errno.  The implementation
+ * thereby the clock producer. (IOW, @id may be identical strings, but clk_get
- * uses @dev and @id to determine the clock consumer, and thereby
+ * may return different clock producers depending on @dev.)
- * the clock producer.  (IOW, @id may be identical strings, but
- * clk_get may return different clock producers depending on @dev.)
  *
  * Drivers must assume that the clock source is not enabled.
  *
- * devm_clk_get should not be called from within interrupt context.
- *
  * The clock will automatically be freed when the device is unbound
  * from the bus.
+ *
+ * Return:
+ * a struct clk corresponding to the clock producer, or
+ * valid IS_ERR() condition containing errno
  */
 struct clk *devm_clk_get(struct udevice *dev, const char *id);
 
 /**
- * devm_clk_get_optional - lookup and obtain a managed reference to an optional
+ * devm_clk_get_optional() - lookup and obtain a managed reference to an
- *			   clock producer.
+ *                           optional clock producer.
  * @dev: device for clock "consumer"
  * @id: clock consumer ID
  *
  * Behaves the same as devm_clk_get() except where there is no clock producer.
- * In this case, instead of returning -ENOENT, the function returns NULL.
+ * In this case, instead of returning -%ENOENT, the function returns NULL.
  */
-struct clk *devm_clk_get_optional(struct udevice *dev, const char *id);
+static inline struct clk *devm_clk_get_optional(struct udevice *dev,
+						const char *id)
+{
+	struct clk *clk = devm_clk_get(dev, id);
+
+	if (PTR_ERR(clk) == -ENODATA)
+		return NULL;
+
+	return clk;
+}
 
 /**
  * clk_release_all() - Disable (turn off)/Free an array of previously
  * requested clocks.
+ * @clk:	A clock struct array that was previously successfully
+ *		requested by clk_request/get_by_*().
+ * @count:	Number of clock contained in the array
  *
  * For each clock contained in the clock array, this function will check if
  * clock has been previously requested and then will disable and free it.
  *
- * @clk:	A clock struct array that was previously successfully
- *		requested by clk_request/get_by_*().
- * @count	Number of clock contained in the array
  * Return: zero on success, or -ve error code.
  */
 int clk_release_all(struct clk *clk, int count);
@@ -290,18 +281,60 @@ clk_get_by_name_nodev(ofnode node, const char *name, struct clk *clk)
 	return -ENOSYS;
 }
 
-static inline int
-clk_get_optional_nodev(ofnode node, const char *name, struct clk *clk)
-{
-	return -ENOSYS;
-}
-
 static inline int clk_release_all(struct clk *clk, int count)
 {
 	return -ENOSYS;
 }
 #endif
 
+/**
+ * clk_get_by_name_optional() - Get/request a optional clock by name.
+ * @dev:	The client device.
+ * @name:	The name of the clock to request, within the client's list of
+ *		clocks.
+ * @clk:	A pointer to a clock struct to initialize.
+ *
+ * Behaves the same as clk_get_by_name(), except when there is no clock
+ * provider. In the latter case, return 0.
+ *
+ * Return: 0 if OK, or a negative error code.
+ */
+static inline int clk_get_by_name_optional(struct udevice *dev,
+					   const char *name, struct clk *clk)
+{
+	int ret;
+
+	ret = clk_get_by_name(dev, name, clk);
+	if (ret == -ENODATA)
+		return 0;
+
+	return ret;
+}
+
+/**
+ * clk_get_by_name_nodev_optional - Get/request an optinonal clock by name
+ *		without a device.
+ * @node:	The client ofnode.
+ * @name:	The name of the clock to request, within the client's list of
+ *		clocks.
+ * @clk:	A pointer to a clock struct to initialize.
+ *
+ * Behaves the same as clk_get_by_name_nodev() except where there is
+ * no clock producer, in this case, skip the error number -%ENODATA, and
+ * the function returns 0.
+ */
+static inline int clk_get_by_name_nodev_optional(ofnode node, const char *name,
+						 struct clk *clk)
+{
+	int ret;
+
+	ret = clk_get_by_name_nodev(node, name, clk);
+	if (ret == -ENODATA)
+		return 0;
+
+	return ret;
+}
+
 /**
  * enum clk_defaults_stage - What stage clk_set_defaults() is called at
  * @CLK_DEFAULTS_PRE: Called before probe. Setting of defaults for clocks owned
@@ -327,12 +360,13 @@ enum clk_defaults_stage {
 
 #if CONFIG_IS_ENABLED(OF_REAL) && CONFIG_IS_ENABLED(CLK)
 /**
- * clk_set_defaults - Process 'assigned-{clocks/clock-parents/clock-rates}'
+ * clk_set_defaults - Process ``assigned-{clocks/clock-parents/clock-rates}``
  *                    properties to configure clocks
- *
  * @dev:        A device to process (the ofnode associated with this device
  *              will be processed).
  * @stage:	The stage of the probing process this function is called during.
+ *
+ * Return: zero on success, or -ve error code.
  */
 int clk_set_defaults(struct udevice *dev, enum clk_defaults_stage stage);
 #else
@@ -345,12 +379,12 @@ static inline int clk_set_defaults(struct udevice *dev, int stage)
 /**
  * clk_release_bulk() - Disable (turn off)/Free an array of previously
  * requested clocks in a clock bulk struct.
+ * @bulk:	A clock bulk struct that was previously successfully
+ *		requested by clk_get_bulk().
  *
  * For each clock contained in the clock bulk struct, this function will check
  * if clock has been previously requested and then will disable and free it.
  *
- * @clk:	A clock bulk struct that was previously successfully
- *		requested by clk_get_bulk().
  * Return: zero on success, or -ve error code.
  */
 static inline int clk_release_bulk(struct clk_bulk *bulk)
@@ -360,35 +394,35 @@ static inline int clk_release_bulk(struct clk_bulk *bulk)
 
 #if CONFIG_IS_ENABLED(CLK)
 /**
- * clk_request - Request a clock by provider-specific ID.
+ * clk_request() - Request a clock by provider-specific ID.
+ * @dev:	The clock provider device.
+ * @clk:	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.
  *
  * 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.
  */
 int clk_request(struct udevice *dev, struct clk *clk);
 
 /**
- * clk_free - Free a previously requested clock.
+ * clk_free() - Free a previously requested clock.
- *
+ * @clk:	A clock struct that was previously successfully requested by
- * @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_free(struct clk *clk);
 
 /**
  * clk_get_rate() - Get current clock rate.
- *
  * @clk:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
+ *
  * Return: clock rate in Hz on success, 0 for invalid clock, or -ve error code
  *	   for other errors.
  */
@@ -396,98 +430,98 @@ ulong clk_get_rate(struct clk *clk);
 
 /**
  * clk_get_parent() - Get current clock's parent.
- *
  * @clk:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
+ *
  * Return: pointer to parent's struct clk, or error code passed as pointer
  */
 struct clk *clk_get_parent(struct clk *clk);
 
 /**
  * clk_get_parent_rate() - Get parent of current clock rate.
- *
  * @clk:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
+ *
  * Return: clock rate in Hz, or -ve error code.
  */
 long long clk_get_parent_rate(struct clk *clk);
 
 /**
  * clk_round_rate() - Adjust a rate to the exact rate a clock can provide
+ * @clk: A clock struct that was previously successfully requested by
+ *       clk_request/get_by_*().
+ * @rate: desired clock rate in Hz.
  *
  * This answers the question "if I were to pass @rate to clk_set_rate(),
  * what clock rate would I end up with?" without changing the hardware
- * in any way.  In other words:
+ * in any way. In other words::
  *
  *   rate = clk_round_rate(clk, r);
  *
- * and:
+ * and::
  *
  *   rate = clk_set_rate(clk, r);
  *
  * are equivalent except the former does not modify the clock hardware
  * in any way.
  *
- * @clk: A clock struct that was previously successfully requested by
- *       clk_request/get_by_*().
- * @rate: desired clock rate in Hz.
  * Return: rounded rate in Hz, or -ve error code.
  */
 ulong clk_round_rate(struct clk *clk, ulong rate);
 
 /**
  * clk_set_rate() - Set current clock rate.
- *
  * @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_rate(struct clk *clk, ulong rate);
 
 /**
  * clk_set_parent() - Set current clock parent.
- *
  * @clk:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
  * @parent:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
+ *
  * Return: new rate, or -ve error code.
  */
 int clk_set_parent(struct clk *clk, struct clk *parent);
 
 /**
  * clk_enable() - Enable (turn on) a clock.
- *
  * @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_enable_bulk() - Enable (turn on) all clocks in a clock bulk struct.
- *
  * @bulk:	A clock bulk struct that was previously successfully requested
  *		by clk_get_bulk().
+ *
  * Return: zero on success, or -ve error code.
  */
 int clk_enable_bulk(struct clk_bulk *bulk);
 
 /**
  * clk_disable() - Disable (turn off) a clock.
- *
  * @clk:	A clock struct that was previously successfully requested by
  *		clk_request/get_by_*().
+ *
  * Return: zero on success, or -ve error code.
  */
 int clk_disable(struct clk *clk);
 
 /**
  * clk_disable_bulk() - Disable (turn off) all clocks in a clock bulk struct.
- *
  * @bulk:	A clock bulk struct that was previously successfully requested
  *		by clk_get_bulk().
+ *
  * Return: zero on success, or -ve error code.
  */
 int clk_disable_bulk(struct clk_bulk *bulk);
@@ -497,28 +531,25 @@ int clk_disable_bulk(struct clk_bulk *bulk);
  * @p: clk compared against q
  * @q: clk compared against p
  *
- * Returns true if the two struct clk pointers both point to the same hardware
+ * Return:
- * clock node.
+ * %true if the two struct clk pointers both point to the same hardware clock
- *
+ * node, and %false otherwise. Note that two %NULL clks are treated as matching.
- * Returns false otherwise. Note that two NULL clks are treated as matching.
  */
 bool clk_is_match(const struct clk *p, const struct clk *q);
 
 /**
  * clk_get_by_id() - Get the clock by its ID
- *
  * @id:	The clock ID to search for
- *
  * @clkp:	A pointer to clock struct that has been found among added clocks
  *              to UCLASS_CLK
+ *
  * Return: zero on success, or -ENOENT on error
  */
 int clk_get_by_id(ulong id, struct clk **clkp);
 
 /**
  * clk_dev_binded() - Check whether the clk has a device binded
- *
+ * @clk:	A pointer to the clk
- * @clk		A pointer to the clk
  *
  * Return: true on binded, or false on no
  */
@@ -604,8 +635,8 @@ static inline bool clk_dev_binded(struct clk *clk)
 
 /**
  * clk_valid() - check if clk is valid
- *
  * @clk:	the clock to check
+ *
  * Return: true if valid, or false
  */
 static inline bool clk_valid(struct clk *clk)