clk: zynq: Add clock wizard driver

The Clocking Wizard IP supports clock circuits customized
to your clocking requirements. The wizard support for
dynamically reconfiguring the clocking primitives for
Multiply, Divide, Phase Shift/Offset, or Duty Cycle.

Limited by U-Boot clk uclass without set_phase API, this
patch only provides set_rate to modify the frequency.

Signed-off-by: Zhengxun <zhengxunli.mxic@gmail.com>
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

drivers/clk/Kconfig

@@ -128,6 +128,17 @@ config CLK_ZYNQ
 	  This clock driver adds support for clock related settings for
 	  Zynq platform.
 
+config CLK_XLNX_CLKWZRD
+	bool "Xilinx Clocking Wizard"
+	depends on CLK
+	help
+	  Support for the Xilinx Clocking Wizard IP core clock generator.
+	  The wizard support for dynamically reconfiguring the clocking
+	  primitives for Multiply, Divide, Phase Shift/Offset, or Duty
+	  Cycle. Limited by U-Boot clk uclass without set_phase API and
+	  set_duty_cycle API, this driver only supports set_rate to modify
+	  the frequency.
+
 config CLK_ZYNQMP
 	bool "Enable clock driver support for ZynqMP"
 	depends on ARCH_ZYNQMP

drivers/clk/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_CLK_UNIPHIER) += uniphier/
 obj-$(CONFIG_CLK_VEXPRESS_OSC) += clk_vexpress_osc.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_ICS8N3QV01) += ics8n3qv01.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o

drivers/clk/clk-xlnx-clock-wizard.c

@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx 'Clocking Wizard' driver
+ *
+ * Copyright (c) 2021 Macronix Inc.
+ *
+ * Author: Zhengxun Li <zhengxunli@mxic.com.tw>
+ */
+
+#include <common.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <div64.h>
+#include <dm/device_compat.h>
+#include <linux/iopoll.h>
+
+#include <linux/bitfield.h>
+
+#define SRR			0x0
+
+#define SR			0x4
+#define SR_LOCKED		BIT(0)
+
+#define CCR(x)			(0x200 + ((x) * 4))
+
+#define FBOUT_CFG		CCR(0)
+#define FBOUT_DIV(x)		(x)
+#define FBOUT_DIV_MASK		GENMASK(7, 0)
+#define FBOUT_GET_DIV(x)	FIELD_GET(FBOUT_DIV_MASK, x)
+#define FBOUT_MUL(x)		((x) << 8)
+#define FBOUT_MUL_MASK		GENMASK(15, 8)
+#define FBOUT_GET_MUL(x)	FIELD_GET(FBOUT_MUL_MASK, x)
+#define FBOUT_FRAC(x)		((x) << 16)
+#define FBOUT_FRAC_MASK		GENMASK(25, 16)
+#define FBOUT_GET_FRAC(x)	FIELD_GET(FBOUT_FRAC_MASK, x)
+#define FBOUT_FRAC_EN		BIT(26)
+
+#define FBOUT_PHASE		CCR(1)
+
+#define OUT_CFG(x)		CCR(2 + ((x) * 3))
+#define OUT_DIV(x)		(x)
+#define OUT_DIV_MASK		GENMASK(7, 0)
+#define OUT_GET_DIV(x)		FIELD_GET(OUT_DIV_MASK, x)
+#define OUT_FRAC(x)		((x) << 8)
+#define OUT_GET_MASK		GENMASK(17, 8)
+#define OUT_GET_FRAC(x)		FIELD_GET(OUT_GET_MASK, x)
+#define OUT_FRAC_EN		BIT(18)
+
+#define OUT_PHASE(x)		CCR(3 + ((x) * 3))
+#define OUT_DUTY(x)		CCR(4 + ((x) * 3))
+
+#define CTRL			CCR(23)
+#define CTRL_SEN		BIT(2)
+#define CTRL_SADDR		BIT(1)
+#define CTRL_LOAD		BIT(0)
+
+/**
+ * struct clkwzrd - Clock wizard private data structure
+ *
+ * @base:		memory base
+ * @vco_clk:		voltage-controlled oscillator frequency
+ *
+ */
+struct clkwzd {
+	void *base;
+	u64 vco_clk;
+};
+
+struct clkwzd_plat {
+	fdt_addr_t addr;
+};
+
+static int clk_wzrd_enable(struct clk *clk)
+{
+	struct clkwzd *priv = dev_get_priv(clk->dev);
+	int ret;
+	u32 val;
+
+	ret = readl_poll_sleep_timeout(priv->base + SR, val, val & SR_LOCKED,
+				       1, 100);
+	if (!ret) {
+		writel(CTRL_SEN | CTRL_SADDR | CTRL_LOAD, priv->base + CTRL);
+		writel(CTRL_SADDR, priv->base + CTRL);
+		ret = readl_poll_sleep_timeout(priv->base + SR, val,
+					       val & SR_LOCKED, 1, 100);
+	}
+
+	return ret;
+}
+
+static unsigned long clk_wzrd_set_rate(struct clk *clk, ulong rate)
+{
+	struct clkwzd *priv = dev_get_priv(clk->dev);
+	u64 div;
+	u32 cfg;
+
+	/* Get output clock divide value */
+	div = DIV_ROUND_DOWN_ULL(priv->vco_clk * 1000, rate);
+	if (div < 1000 || div > 255999)
+		return -EINVAL;
+
+	cfg = OUT_DIV((u32)div / 1000);
+
+	writel(cfg, priv->base + OUT_CFG(clk->id));
+
+	return 0;
+}
+
+static struct clk_ops clk_wzrd_ops = {
+	.enable = clk_wzrd_enable,
+	.set_rate = clk_wzrd_set_rate,
+};
+
+static int clk_wzrd_probe(struct udevice *dev)
+{
+	struct clkwzd_plat *plat = dev_get_plat(dev);
+	struct clkwzd *priv = dev_get_priv(dev);
+	struct clk clk_in1;
+	u64 clock, vco_clk;
+	u32 cfg;
+	int ret;
+
+	priv->base = (void *)plat->addr;
+
+	ret = clk_get_by_name(dev, "clk_in1", &clk_in1);
+	if (ret < 0) {
+		dev_err(dev, "failed to get clock\n");
+		return ret;
+	}
+
+	clock = clk_get_rate(&clk_in1);
+	if (IS_ERR_VALUE(clock)) {
+		dev_err(dev, "failed to get rate\n");
+		return clock;
+	}
+
+	ret = clk_enable(&clk_in1);
+	if (ret) {
+		dev_err(dev, "failed to enable clock\n");
+		clk_free(&clk_in1);
+		return ret;
+	}
+
+	/* Read clock configuration registers */
+	cfg = readl(priv->base + FBOUT_CFG);
+
+	/* Recalculate VCO rate */
+	if (cfg & FBOUT_FRAC_EN)
+		vco_clk = DIV_ROUND_DOWN_ULL(clock *
+					     ((FBOUT_GET_MUL(cfg) * 1000) +
+					      FBOUT_GET_FRAC(cfg)),
+					     1000);
+	else
+		vco_clk = clock * FBOUT_GET_MUL(cfg);
+
+	priv->vco_clk = DIV_ROUND_DOWN_ULL(vco_clk, FBOUT_GET_DIV(cfg));
+
+	return 0;
+}
+
+static int clk_wzrd_of_to_plat(struct udevice *dev)
+{
+	struct clkwzd_plat *plat = dev_get_plat(dev);
+
+	plat->addr = dev_read_addr(dev);
+	if (plat->addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct udevice_id clk_wzrd_ids[] = {
+	{ .compatible = "xlnx,clocking-wizard" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(clk_wzrd) = {
+	.name = "zynq-clk-wizard",
+	.id = UCLASS_CLK,
+	.of_match = clk_wzrd_ids,
+	.ops = &clk_wzrd_ops,
+	.probe = clk_wzrd_probe,
+	.of_to_plat = clk_wzrd_of_to_plat,
+	.priv_auto = sizeof(struct clkwzd),
+	.plat_auto = sizeof(struct clkwzd_plat),
+};