clk: sandbox: Add sandbox test code for Common Clock Framework [CCF]

This patch provides code to implement the CCF clock tree in sandbox. It
uses all the introduced primitives; some generic ones are reused, some
sandbox specific were developed.

In that way (after introducing the real CCF tree in sandbox) the recently
added to clk-uclass.c: clk_get_by_id() and clk_get_parent_rate() are tested
in their natural work environment.

Usage (sandbox_defconfig and sandbox_flattree_defconfig):
./u-boot --fdt arch/sandbox/dts/test.dtb --command "ut dm clk_ccf"

Signed-off-by: Lukasz Majewski <lukma@denx.de>

arch/sandbox/dts/test.dts

@@ -232,6 +232,10 @@
 		clock-names = "fixed", "i2c", "spi";
 	};
 
+	ccf: clk-ccf {
+		compatible = "sandbox,clk-ccf";
+	};
+
 	eth@10002000 {
 		compatible = "sandbox,eth";
 		reg = <0x10002000 0x1000>;

drivers/clk/Kconfig

@@ -55,7 +55,7 @@ config SPL_CLK_CCF
 
 config CLK_CCF
 	bool "Common Clock Framework [CCF] support "
-	depends on CLK_IMX6Q
+	depends on CLK_IMX6Q || SANDBOX_CLK_CCF
 	help
 	  Enable this option if you want to (re-)use the Linux kernel's Common
 	  Clock Framework [CCF] code in U-Boot's clock driver.
@@ -138,4 +138,12 @@ config CLK_MPC83XX
 	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.
+
 endmenu

drivers/clk/Makefile

@@ -38,5 +38,6 @@ obj-$(CONFIG_ICS8N3QV01) += ics8n3qv01.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.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_TI_SCI) += clk-ti-sci.o

drivers/clk/clk_sandbox_ccf.c

@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ *
+ * Common Clock Framework [CCF] driver for Sandbox
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <clk.h>
+#include <asm/clk.h>
+#include <clk-uclass.h>
+#include <linux/clk-provider.h>
+#include <sandbox-clk.h>
+
+/*
+ * Sandbox implementation of CCF primitives necessary for clk-uclass testing
+ *
+ * --- Sandbox PLLv3 ---
+ */
+struct clk_pllv3 {
+	struct clk	clk;
+	u32		div_mask;
+	u32		div_shift;
+};
+
+static ulong clk_pllv3_get_rate(struct clk *clk)
+{
+	unsigned long parent_rate = clk_get_parent_rate(clk);
+
+	return parent_rate * 24;
+}
+
+static const struct clk_ops clk_pllv3_generic_ops = {
+	.get_rate       = clk_pllv3_get_rate,
+};
+
+struct clk *sandbox_clk_pllv3(enum sandbox_pllv3_type type, const char *name,
+			      const char *parent_name, void __iomem *base,
+			      u32 div_mask)
+{
+	struct clk_pllv3 *pll;
+	struct clk *clk;
+	char *drv_name = "sandbox_clk_pllv3";
+	int ret;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	pll->div_mask = div_mask;
+	clk = &pll->clk;
+
+	ret = clk_register(clk, drv_name, name, parent_name);
+	if (ret) {
+		kfree(pll);
+		return ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+U_BOOT_DRIVER(sandbox_clk_pll_generic) = {
+	.name	= "sandbox_clk_pllv3",
+	.id	= UCLASS_CLK,
+	.ops	= &clk_pllv3_generic_ops,
+};
+
+/* --- Sandbox PLLv3 --- */
+/* --- Sandbox Gate  --- */
+struct clk_gate2 {
+	struct clk clk;
+	bool	state;
+};
+
+#define to_clk_gate2(_clk) container_of(_clk, struct clk_gate2, clk)
+
+static int clk_gate2_enable(struct clk *clk)
+{
+	struct clk_gate2 *gate = to_clk_gate2(dev_get_clk_ptr(clk->dev));
+
+	gate->state = 1;
+	return 0;
+}
+
+static int clk_gate2_disable(struct clk *clk)
+{
+	struct clk_gate2 *gate = to_clk_gate2(dev_get_clk_ptr(clk->dev));
+
+	gate->state = 0;
+	return 0;
+}
+
+static const struct clk_ops clk_gate2_ops = {
+	.enable = clk_gate2_enable,
+	.disable = clk_gate2_disable,
+	.get_rate = clk_generic_get_rate,
+};
+
+struct clk *sandbox_clk_register_gate2(struct device *dev, const char *name,
+				       const char *parent_name,
+				       unsigned long flags, void __iomem *reg,
+				       u8 bit_idx, u8 cgr_val,
+				       u8 clk_gate2_flags)
+{
+	struct clk_gate2 *gate;
+	struct clk *clk;
+	int ret;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	gate->state = 0;
+	clk = &gate->clk;
+
+	ret = clk_register(clk, "sandbox_clk_gate2", name, parent_name);
+	if (ret) {
+		kfree(gate);
+		return ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+U_BOOT_DRIVER(sandbox_clk_gate2) = {
+	.name	= "sandbox_clk_gate2",
+	.id	= UCLASS_CLK,
+	.ops	= &clk_gate2_ops,
+};
+
+/* --- Sandbox Gate --- */
+/* The CCF core driver itself */
+static const struct udevice_id sandbox_clk_ccf_test_ids[] = {
+	{ .compatible = "sandbox,clk-ccf" },
+	{ }
+};
+
+static const char *const usdhc_sels[] = { "pll3_60m", "pll3_80m", };
+
+static int sandbox_clk_ccf_probe(struct udevice *dev)
+{
+	void *base = NULL;
+	u32 reg;
+
+	clk_dm(SANDBOX_CLK_PLL3,
+	       sandbox_clk_pllv3(SANDBOX_PLLV3_USB, "pll3_usb_otg", "osc",
+				 base + 0x10, 0x3));
+
+	clk_dm(SANDBOX_CLK_PLL3_60M,
+	       sandbox_clk_fixed_factor("pll3_60m",  "pll3_usb_otg",   1, 8));
+
+	clk_dm(SANDBOX_CLK_PLL3_80M,
+	       sandbox_clk_fixed_factor("pll3_80m",  "pll3_usb_otg",   1, 6));
+
+	/* The HW adds +1 to the divider value (2+1) is the divider */
+	reg = (2 << 19);
+	clk_dm(SANDBOX_CLK_ECSPI_ROOT,
+	       sandbox_clk_divider("ecspi_root", "pll3_60m", &reg, 19, 6));
+
+	clk_dm(SANDBOX_CLK_ECSPI1,
+	       sandbox_clk_gate2("ecspi1", "ecspi_root", base + 0x6c, 0));
+
+	/* Select 'pll3_60m' */
+	reg = 0;
+	clk_dm(SANDBOX_CLK_USDHC1_SEL,
+	       sandbox_clk_mux("usdhc1_sel", &reg, 16, 1, usdhc_sels,
+			       ARRAY_SIZE(usdhc_sels)));
+
+	/* Select 'pll3_80m' */
+	reg = BIT(17);
+	clk_dm(SANDBOX_CLK_USDHC2_SEL,
+	       sandbox_clk_mux("usdhc2_sel", &reg, 17, 1, usdhc_sels,
+			       ARRAY_SIZE(usdhc_sels)));
+
+	return 0;
+}
+
+U_BOOT_DRIVER(sandbox_clk_ccf) = {
+	.name = "sandbox_clk_ccf",
+	.id = UCLASS_CLK,
+	.probe = sandbox_clk_ccf_probe,
+	.of_match = sandbox_clk_ccf_test_ids,
+};

include/sandbox-clk.h

@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ */
+
+#ifndef __SANDBOX_CLK_H__
+#define __SANDBOX_CLK_H__
+
+#include <linux/clk-provider.h>
+
+enum {
+	SANDBOX_CLK_PLL2 = 1,
+	SANDBOX_CLK_PLL3,
+	SANDBOX_CLK_PLL3_60M,
+	SANDBOX_CLK_PLL3_80M,
+	SANDBOX_CLK_ECSPI_ROOT,
+	SANDBOX_CLK_ECSPI0,
+	SANDBOX_CLK_ECSPI1,
+	SANDBOX_CLK_USDHC1_SEL,
+	SANDBOX_CLK_USDHC2_SEL,
+};
+
+enum sandbox_pllv3_type {
+	SANDBOX_PLLV3_GENERIC,
+	SANDBOX_PLLV3_USB,
+};
+
+struct clk *sandbox_clk_pllv3(enum sandbox_pllv3_type type, const char *name,
+			      const char *parent_name, void __iomem *base,
+			      u32 div_mask);
+
+static inline struct clk *sandbox_clk_fixed_factor(const char *name,
+						   const char *parent,
+						   unsigned int mult,
+						   unsigned int div)
+{
+	return clk_register_fixed_factor(NULL, name, parent,
+			CLK_SET_RATE_PARENT, mult, div);
+}
+
+static inline struct clk *sandbox_clk_divider(const char *name,
+					      const char *parent,
+					      void __iomem *reg, u8 shift,
+					      u8 width)
+{
+	return clk_register_divider(NULL, name, parent, CLK_SET_RATE_PARENT,
+			reg, shift, width, 0);
+}
+
+struct clk *sandbox_clk_register_gate2(struct device *dev, const char *name,
+				       const char *parent_name,
+				       unsigned long flags,
+				       void __iomem *reg, u8 bit_idx,
+				       u8 cgr_val, u8 clk_gate_flags);
+
+static inline struct clk *sandbox_clk_gate2(const char *name,
+					    const char *parent,
+					    void __iomem *reg, u8 shift)
+{
+	return sandbox_clk_register_gate2(NULL, name, parent,
+					  CLK_SET_RATE_PARENT, reg, shift,
+					  0x3, 0);
+}
+
+static inline struct clk *sandbox_clk_mux(const char *name, void __iomem *reg,
+					  u8 shift, u8 width,
+					  const char * const *parents,
+					  int num_parents)
+{
+	return clk_register_mux(NULL, name, parents, num_parents,
+				CLK_SET_RATE_NO_REPARENT, reg, shift,
+				width, 0);
+}
+
+#endif /* __SANDBOX_CLK_H__ */

test/dm/Makefile

@@ -17,7 +17,7 @@ obj-$(CONFIG_SOUND) += audio.o
 obj-$(CONFIG_BLK) += blk.o
 obj-$(CONFIG_BOARD) += board.o
 obj-$(CONFIG_DM_BOOTCOUNT) += bootcount.o
-obj-$(CONFIG_CLK) += clk.o
+obj-$(CONFIG_CLK) += clk.o clk_ccf.o
 obj-$(CONFIG_DM_ETH) += eth.o
 obj-$(CONFIG_FIRMWARE) += firmware.o
 obj-$(CONFIG_DM_GPIO) += gpio.o

test/dm/clk_ccf.c

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <asm/clk.h>
+#include <dm/test.h>
+#include <dm/uclass.h>
+#include <linux/err.h>
+#include <test/ut.h>
+#include <sandbox-clk.h>
+
+/* Tests for Common Clock Framework driver */
+static int dm_test_clk_ccf(struct unit_test_state *uts)
+{
+	struct clk *clk, *pclk;
+	struct udevice *dev;
+	long long rate;
+	int ret;
+
+	/* Get the device using the clk device */
+	ut_assertok(uclass_get_device_by_name(UCLASS_CLK, "clk-ccf", &dev));
+
+	/* Test for clk_get_by_id() */
+	ret = clk_get_by_id(SANDBOX_CLK_ECSPI_ROOT, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("ecspi_root", clk->dev->name);
+
+	/* Test for clk_get_parent_rate() */
+	ret = clk_get_by_id(SANDBOX_CLK_ECSPI1, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("ecspi1", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 20000000);
+
+	/* Test the mux of CCF */
+	ret = clk_get_by_id(SANDBOX_CLK_USDHC1_SEL, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("usdhc1_sel", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 60000000);
+
+	ret = clk_get_by_id(SANDBOX_CLK_USDHC2_SEL, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("usdhc2_sel", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 80000000);
+
+	pclk = clk_get_parent(clk);
+	ut_asserteq_str("pll3_80m", pclk->dev->name);
+
+	return 1;
+}
+
+DM_TEST(dm_test_clk_ccf, DM_TESTF_SCAN_FDT);