zynq: Provide a framework to read clock frequencies

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/cpu/armv7/zynq/Makefile

@@ -12,3 +12,4 @@ obj-y	:= timer.o
 obj-y	+= cpu.o
 obj-y	+= ddrc.o
 obj-y	+= slcr.o
+obj-y	+= clk.o

arch/arm/cpu/armv7/zynq/clk.c

@@ -0,0 +1,638 @@
+/*
+ * Copyright (C) 2013 Soren Brinkmann <soren.brinkmann@xilinx.com>
+ * Copyright (C) 2013 Xilinx, Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/clk.h>
+
+/* Board oscillator frequency */
+#ifndef CONFIG_ZYNQ_PS_CLK_FREQ
+# define CONFIG_ZYNQ_PS_CLK_FREQ	33333333UL
+#endif
+
+/* Register bitfield defines */
+#define PLLCTRL_FBDIV_MASK	0x7f000
+#define PLLCTRL_FBDIV_SHIFT	12
+#define PLLCTRL_BPFORCE_MASK	(1 << 4)
+#define PLLCTRL_PWRDWN_MASK	2
+#define PLLCTRL_PWRDWN_SHIFT	1
+#define PLLCTRL_RESET_MASK	1
+#define PLLCTRL_RESET_SHIFT	0
+
+#define ZYNQ_CLK_MAXDIV		0x3f
+#define CLK_CTRL_DIV1_SHIFT	20
+#define CLK_CTRL_DIV1_MASK	(ZYNQ_CLK_MAXDIV << CLK_CTRL_DIV1_SHIFT)
+#define CLK_CTRL_DIV0_SHIFT	8
+#define CLK_CTRL_DIV0_MASK	(ZYNQ_CLK_MAXDIV << CLK_CTRL_DIV0_SHIFT)
+#define CLK_CTRL_SRCSEL_SHIFT	4
+#define CLK_CTRL_SRCSEL_MASK	(0x3 << CLK_CTRL_SRCSEL_SHIFT)
+
+#define CLK_CTRL_DIV2X_SHIFT	26
+#define CLK_CTRL_DIV2X_MASK	(ZYNQ_CLK_MAXDIV << CLK_CTRL_DIV2X_SHIFT)
+#define CLK_CTRL_DIV3X_SHIFT	20
+#define CLK_CTRL_DIV3X_MASK	(ZYNQ_CLK_MAXDIV << CLK_CTRL_DIV3X_SHIFT)
+
+#define ZYNQ_CLKMUX_SEL_0	0
+#define ZYNQ_CLKMUX_SEL_1	1
+#define ZYNQ_CLKMUX_SEL_2	2
+#define ZYNQ_CLKMUX_SEL_3	3
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct clk;
+
+/**
+ * struct clk_ops:
+ * @set_rate:	Function pointer to set_rate() implementation
+ * @get_rate:	Function pointer to get_rate() implementation
+ */
+struct clk_ops {
+	int (*set_rate)(struct clk *clk, unsigned long rate);
+	unsigned long (*get_rate)(struct clk *clk);
+};
+
+/**
+ * struct clk:
+ * @name:	Clock name
+ * @frequency:	Currenct frequency
+ * @parent:	Parent clock
+ * @flags:	Clock flags
+ * @reg:	Clock control register
+ * @ops:	Clock operations
+ */
+struct clk {
+	char		*name;
+	unsigned long	frequency;
+	enum zynq_clk	parent;
+	unsigned int	flags;
+	u32		*reg;
+	struct clk_ops	ops;
+};
+#define ZYNQ_CLK_FLAGS_HAS_2_DIVS	1
+
+static struct clk clks[clk_max];
+
+/**
+ * __zynq_clk_cpu_get_parent() - Decode clock multiplexer
+ * @srcsel:	Mux select value
+ * Returns the clock identifier associated with the selected mux input.
+ */
+static int __zynq_clk_cpu_get_parent(unsigned int srcsel)
+{
+	unsigned int ret;
+
+	switch (srcsel) {
+	case ZYNQ_CLKMUX_SEL_0:
+	case ZYNQ_CLKMUX_SEL_1:
+		ret = armpll_clk;
+		break;
+	case ZYNQ_CLKMUX_SEL_2:
+		ret = ddrpll_clk;
+		break;
+	case ZYNQ_CLKMUX_SEL_3:
+		ret = iopll_clk;
+		break;
+	default:
+		ret = armpll_clk;
+		break;
+	}
+
+	return ret;
+}
+
+/**
+ * ddr2x_get_rate() - Get clock rate of DDR2x clock
+ * @clk:	Clock handle
+ * Returns the current clock rate of @clk.
+ */
+static unsigned long ddr2x_get_rate(struct clk *clk)
+{
+	u32 clk_ctrl = readl(clk->reg);
+	u32 div = (clk_ctrl & CLK_CTRL_DIV2X_MASK) >> CLK_CTRL_DIV2X_SHIFT;
+
+	return DIV_ROUND_CLOSEST(zynq_clk_get_rate(clk->parent), div);
+}
+
+/**
+ * ddr3x_get_rate() - Get clock rate of DDR3x clock
+ * @clk:	Clock handle
+ * Returns the current clock rate of @clk.
+ */
+static unsigned long ddr3x_get_rate(struct clk *clk)
+{
+	u32 clk_ctrl = readl(clk->reg);
+	u32 div = (clk_ctrl & CLK_CTRL_DIV3X_MASK) >> CLK_CTRL_DIV3X_SHIFT;
+
+	return DIV_ROUND_CLOSEST(zynq_clk_get_rate(clk->parent), div);
+}
+
+static void init_ddr_clocks(void)
+{
+	u32 div0, div1;
+	unsigned long prate = zynq_clk_get_rate(ddrpll_clk);
+	u32 clk_ctrl = readl(&slcr_base->ddr_clk_ctrl);
+
+	/* DDR2x */
+	clks[ddr2x_clk].reg = &slcr_base->ddr_clk_ctrl;
+	clks[ddr2x_clk].parent = ddrpll_clk;
+	clks[ddr2x_clk].name = "ddr_2x";
+	clks[ddr2x_clk].frequency = ddr2x_get_rate(&clks[ddr2x_clk]);
+	clks[ddr2x_clk].ops.get_rate = ddr2x_get_rate;
+
+	/* DDR3x */
+	clks[ddr3x_clk].reg = &slcr_base->ddr_clk_ctrl;
+	clks[ddr3x_clk].parent = ddrpll_clk;
+	clks[ddr3x_clk].name = "ddr_3x";
+	clks[ddr3x_clk].frequency = ddr3x_get_rate(&clks[ddr3x_clk]);
+	clks[ddr3x_clk].ops.get_rate = ddr3x_get_rate;
+
+	/* DCI */
+	clk_ctrl = readl(&slcr_base->dci_clk_ctrl);
+	div0 = (clk_ctrl & CLK_CTRL_DIV0_MASK) >> CLK_CTRL_DIV0_SHIFT;
+	div1 = (clk_ctrl & CLK_CTRL_DIV1_MASK) >> CLK_CTRL_DIV1_SHIFT;
+	clks[dci_clk].reg = &slcr_base->dci_clk_ctrl;
+	clks[dci_clk].parent = ddrpll_clk;
+	clks[dci_clk].frequency = DIV_ROUND_CLOSEST(
+			DIV_ROUND_CLOSEST(prate, div0), div1);
+	clks[dci_clk].name = "dci";
+}
+
+static void init_cpu_clocks(void)
+{
+	int clk_621;
+	u32 reg, div, srcsel;
+	enum zynq_clk parent;
+
+	reg = readl(&slcr_base->arm_clk_ctrl);
+	clk_621 = readl(&slcr_base->clk_621_true) & 1;
+	div = (reg & CLK_CTRL_DIV0_MASK) >> CLK_CTRL_DIV0_SHIFT;
+	srcsel = (reg & CLK_CTRL_SRCSEL_MASK) >> CLK_CTRL_SRCSEL_SHIFT;
+	parent = __zynq_clk_cpu_get_parent(srcsel);
+
+	/* cpu clocks */
+	clks[cpu_6or4x_clk].reg = &slcr_base->arm_clk_ctrl;
+	clks[cpu_6or4x_clk].parent = parent;
+	clks[cpu_6or4x_clk].frequency = DIV_ROUND_CLOSEST(
+			zynq_clk_get_rate(parent), div);
+	clks[cpu_6or4x_clk].name = "cpu_6or4x";
+
+	clks[cpu_3or2x_clk].reg = &slcr_base->arm_clk_ctrl;
+	clks[cpu_3or2x_clk].parent = cpu_6or4x_clk;
+	clks[cpu_3or2x_clk].frequency = zynq_clk_get_rate(cpu_6or4x_clk) / 2;
+	clks[cpu_3or2x_clk].name = "cpu_3or2x";
+
+	clks[cpu_2x_clk].reg = &slcr_base->arm_clk_ctrl;
+	clks[cpu_2x_clk].parent = cpu_6or4x_clk;
+	clks[cpu_2x_clk].frequency = zynq_clk_get_rate(cpu_6or4x_clk) /
+			(2 + clk_621);
+	clks[cpu_2x_clk].name = "cpu_2x";
+
+	clks[cpu_1x_clk].reg = &slcr_base->arm_clk_ctrl;
+	clks[cpu_1x_clk].parent = cpu_6or4x_clk;
+	clks[cpu_1x_clk].frequency = zynq_clk_get_rate(cpu_6or4x_clk) /
+			(4 + 2 * clk_621);
+	clks[cpu_1x_clk].name = "cpu_1x";
+}
+
+/**
+ * periph_calc_two_divs() - Calculate clock dividers
+ * @cur_rate:	Current clock rate
+ * @tgt_rate:	Target clock rate
+ * @prate:	Parent clock rate
+ * @div0:	First divider (output)
+ * @div1:	Second divider (output)
+ * Returns the actual clock rate possible.
+ *
+ * Calculates clock dividers for clocks with two 6-bit dividers.
+ */
+static unsigned long periph_calc_two_divs(unsigned long cur_rate,
+		unsigned long tgt_rate, unsigned long prate, u32 *div0,
+		u32 *div1)
+{
+	long err, best_err = (long)(~0UL >> 1);
+	unsigned long rate, best_rate = 0;
+	u32 d0, d1;
+
+	for (d0 = 1; d0 <= ZYNQ_CLK_MAXDIV; d0++) {
+		for (d1 = 1; d1 <= ZYNQ_CLK_MAXDIV >> 1; d1++) {
+			rate = DIV_ROUND_CLOSEST(DIV_ROUND_CLOSEST(prate, d0),
+					d1);
+			err = abs(rate - tgt_rate);
+
+			if (err < best_err) {
+				*div0 = d0;
+				*div1 = d1;
+				best_err = err;
+				best_rate = rate;
+			}
+		}
+	}
+
+	return best_rate;
+}
+
+/**
+ * zynq_clk_periph_set_rate() - Set clock rate
+ * @clk:	Handle of the peripheral clock
+ * @rate:	New clock rate
+ * Sets the clock frequency of @clk to @rate. Returns zero on success.
+ */
+static int zynq_clk_periph_set_rate(struct clk *clk,
+		unsigned long rate)
+{
+	u32 ctrl, div0 = 0, div1 = 0;
+	unsigned long prate, new_rate, cur_rate = clk->frequency;
+
+	ctrl = readl(clk->reg);
+	prate = zynq_clk_get_rate(clk->parent);
+	ctrl &= ~CLK_CTRL_DIV0_MASK;
+
+	if (clk->flags & ZYNQ_CLK_FLAGS_HAS_2_DIVS) {
+		ctrl &= ~CLK_CTRL_DIV1_MASK;
+		new_rate = periph_calc_two_divs(cur_rate, rate, prate, &div0,
+				&div1);
+		ctrl |= div1 << CLK_CTRL_DIV1_SHIFT;
+	} else {
+		div0 = DIV_ROUND_CLOSEST(prate, rate);
+		div0 &= ZYNQ_CLK_MAXDIV;
+		new_rate = DIV_ROUND_CLOSEST(rate, div0);
+	}
+
+	/* write new divs to hardware */
+	ctrl |= div0 << CLK_CTRL_DIV0_SHIFT;
+	writel(ctrl, clk->reg);
+
+	/* update frequency in clk framework */
+	clk->frequency = new_rate;
+
+	return 0;
+}
+
+/**
+ * zynq_clk_periph_get_rate() - Get clock rate
+ * @clk:	Handle of the peripheral clock
+ * Returns the current clock rate of @clk.
+ */
+static unsigned long zynq_clk_periph_get_rate(struct clk *clk)
+{
+	u32 clk_ctrl = readl(clk->reg);
+	u32 div0 = (clk_ctrl & CLK_CTRL_DIV0_MASK) >> CLK_CTRL_DIV0_SHIFT;
+	u32 div1 = 1;
+
+	if (clk->flags & ZYNQ_CLK_FLAGS_HAS_2_DIVS)
+		div1 = (clk_ctrl & CLK_CTRL_DIV1_MASK) >> CLK_CTRL_DIV1_SHIFT;
+
+	/* a register value of zero == division by 1 */
+	if (!div0)
+		div0 = 1;
+	if (!div1)
+		div1 = 1;
+
+	return
+		DIV_ROUND_CLOSEST(
+			DIV_ROUND_CLOSEST(zynq_clk_get_rate(clk->parent), div0),
+			div1);
+}
+
+/**
+ * __zynq_clk_periph_get_parent() - Decode clock multiplexer
+ * @srcsel:	Mux select value
+ * Returns the clock identifier associated with the selected mux input.
+ */
+static enum zynq_clk __zynq_clk_periph_get_parent(u32 srcsel)
+{
+	switch (srcsel) {
+	case ZYNQ_CLKMUX_SEL_0:
+	case ZYNQ_CLKMUX_SEL_1:
+		return iopll_clk;
+	case ZYNQ_CLKMUX_SEL_2:
+		return armpll_clk;
+	case ZYNQ_CLKMUX_SEL_3:
+		return ddrpll_clk;
+	default:
+		return 0;
+	}
+}
+
+/**
+ * zynq_clk_periph_get_parent() - Decode clock multiplexer
+ * @clk:	Clock handle
+ * Returns the clock identifier associated with the selected mux input.
+ */
+static enum zynq_clk zynq_clk_periph_get_parent(struct clk *clk)
+{
+	u32 clk_ctrl = readl(clk->reg);
+	u32 srcsel = (clk_ctrl & CLK_CTRL_SRCSEL_MASK) >> CLK_CTRL_SRCSEL_SHIFT;
+
+	return __zynq_clk_periph_get_parent(srcsel);
+}
+
+/**
+ * zynq_clk_register_periph_clk() - Set up a peripheral clock with the framework
+ * @clk:	Pointer to struct clk for the clock
+ * @ctrl:	Clock control register
+ * @name:	PLL name
+ * @two_divs:	Indicates whether the clock features one or two dividers
+ */
+static int zynq_clk_register_periph_clk(struct clk *clk, u32 *ctrl, char *name,
+		bool two_divs)
+{
+	clk->name = name;
+	clk->reg = ctrl;
+	if (two_divs)
+		clk->flags = ZYNQ_CLK_FLAGS_HAS_2_DIVS;
+	clk->parent = zynq_clk_periph_get_parent(clk);
+	clk->frequency = zynq_clk_periph_get_rate(clk);
+	clk->ops.get_rate = zynq_clk_periph_get_rate;
+	clk->ops.set_rate = zynq_clk_periph_set_rate;
+
+	return 0;
+}
+
+static void init_periph_clocks(void)
+{
+	zynq_clk_register_periph_clk(&clks[gem0_clk], &slcr_base->gem0_clk_ctrl,
+				     "gem0", 1);
+	zynq_clk_register_periph_clk(&clks[gem1_clk], &slcr_base->gem1_clk_ctrl,
+				     "gem1", 1);
+
+	zynq_clk_register_periph_clk(&clks[smc_clk], &slcr_base->smc_clk_ctrl,
+				     "smc", 0);
+
+	zynq_clk_register_periph_clk(&clks[lqspi_clk],
+				     &slcr_base->lqspi_clk_ctrl, "lqspi", 0);
+
+	zynq_clk_register_periph_clk(&clks[sdio0_clk],
+				     &slcr_base->sdio_clk_ctrl, "sdio0", 0);
+	zynq_clk_register_periph_clk(&clks[sdio1_clk],
+				     &slcr_base->sdio_clk_ctrl, "sdio1", 0);
+
+	zynq_clk_register_periph_clk(&clks[spi0_clk], &slcr_base->spi_clk_ctrl,
+				     "spi0", 0);
+	zynq_clk_register_periph_clk(&clks[spi1_clk], &slcr_base->spi_clk_ctrl,
+				     "spi1", 0);
+
+	zynq_clk_register_periph_clk(&clks[uart0_clk],
+				     &slcr_base->uart_clk_ctrl, "uart0", 0);
+	zynq_clk_register_periph_clk(&clks[uart1_clk],
+				     &slcr_base->uart_clk_ctrl, "uart1", 0);
+
+	zynq_clk_register_periph_clk(&clks[dbg_trc_clk],
+				     &slcr_base->dbg_clk_ctrl, "dbg_trc", 0);
+	zynq_clk_register_periph_clk(&clks[dbg_apb_clk],
+				     &slcr_base->dbg_clk_ctrl, "dbg_apb", 0);
+
+	zynq_clk_register_periph_clk(&clks[pcap_clk],
+				     &slcr_base->pcap_clk_ctrl, "pcap", 0);
+
+	zynq_clk_register_periph_clk(&clks[fclk0_clk],
+				     &slcr_base->fpga0_clk_ctrl, "fclk0", 1);
+	zynq_clk_register_periph_clk(&clks[fclk1_clk],
+				     &slcr_base->fpga1_clk_ctrl, "fclk1", 1);
+	zynq_clk_register_periph_clk(&clks[fclk2_clk],
+				     &slcr_base->fpga2_clk_ctrl, "fclk2", 1);
+	zynq_clk_register_periph_clk(&clks[fclk3_clk],
+				     &slcr_base->fpga3_clk_ctrl, "fclk3", 1);
+}
+
+/**
+ * zynq_clk_register_aper_clk() - Set up a APER clock with the framework
+ * @clk:	Pointer to struct clk for the clock
+ * @ctrl:	Clock control register
+ * @name:	PLL name
+ */
+static void zynq_clk_register_aper_clk(struct clk *clk, u32 *ctrl, char *name)
+{
+	clk->name = name;
+	clk->reg = ctrl;
+	clk->parent = cpu_1x_clk;
+	clk->frequency = zynq_clk_get_rate(clk->parent);
+}
+
+static void init_aper_clocks(void)
+{
+	zynq_clk_register_aper_clk(&clks[usb0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "usb0_aper");
+	zynq_clk_register_aper_clk(&clks[usb1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "usb1_aper");
+
+	zynq_clk_register_aper_clk(&clks[gem0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "gem0_aper");
+	zynq_clk_register_aper_clk(&clks[gem1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "gem1_aper");
+
+	zynq_clk_register_aper_clk(&clks[sdio0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "sdio0_aper");
+	zynq_clk_register_aper_clk(&clks[sdio1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "sdio1_aper");
+
+	zynq_clk_register_aper_clk(&clks[spi0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "spi0_aper");
+	zynq_clk_register_aper_clk(&clks[spi1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "spi1_aper");
+
+	zynq_clk_register_aper_clk(&clks[can0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "can0_aper");
+	zynq_clk_register_aper_clk(&clks[can1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "can1_aper");
+
+	zynq_clk_register_aper_clk(&clks[i2c0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "i2c0_aper");
+	zynq_clk_register_aper_clk(&clks[i2c1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "i2c1_aper");
+
+	zynq_clk_register_aper_clk(&clks[uart0_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "uart0_aper");
+	zynq_clk_register_aper_clk(&clks[uart1_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "uart1_aper");
+
+	zynq_clk_register_aper_clk(&clks[gpio_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "gpio_aper");
+
+	zynq_clk_register_aper_clk(&clks[lqspi_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "lqspi_aper");
+
+	zynq_clk_register_aper_clk(&clks[smc_aper_clk],
+				   &slcr_base->aper_clk_ctrl, "smc_aper");
+}
+
+/**
+ * __zynq_clk_pll_get_rate() - Get PLL rate
+ * @addr:	Address of the PLL's control register
+ * Returns the current PLL output rate.
+ */
+static unsigned long __zynq_clk_pll_get_rate(u32 *addr)
+{
+	u32 reg, mul, bypass;
+
+	reg = readl(addr);
+	bypass = reg & PLLCTRL_BPFORCE_MASK;
+	if (bypass)
+		mul = 1;
+	else
+		mul = (reg & PLLCTRL_FBDIV_MASK) >> PLLCTRL_FBDIV_SHIFT;
+
+	return CONFIG_ZYNQ_PS_CLK_FREQ * mul;
+}
+
+/**
+ * zynq_clk_pll_get_rate() - Get PLL rate
+ * @pll:	Handle of the PLL
+ * Returns the current clock rate of @pll.
+ */
+static unsigned long zynq_clk_pll_get_rate(struct clk *pll)
+{
+	return __zynq_clk_pll_get_rate(pll->reg);
+}
+
+/**
+ * zynq_clk_register_pll() - Set up a PLL with the framework
+ * @clk:	Pointer to struct clk for the PLL
+ * @ctrl:	PLL control register
+ * @name:	PLL name
+ * @prate:	PLL input clock rate
+ */
+static void zynq_clk_register_pll(struct clk *clk, u32 *ctrl, char *name,
+		unsigned long prate)
+{
+	clk->name = name;
+	clk->reg = ctrl;
+	clk->frequency = zynq_clk_pll_get_rate(clk);
+	clk->ops.get_rate = zynq_clk_pll_get_rate;
+}
+
+/**
+ * clkid_2_register() - Get clock control register
+ * @id:	Clock identifier of one of the PLLs
+ * Returns the address of the requested PLL's control register.
+ */
+static u32 *clkid_2_register(enum zynq_clk id)
+{
+	switch (id) {
+	case armpll_clk:
+		return &slcr_base->arm_pll_ctrl;
+	case ddrpll_clk:
+		return &slcr_base->ddr_pll_ctrl;
+	case iopll_clk:
+		return &slcr_base->io_pll_ctrl;
+	default:
+		return &slcr_base->io_pll_ctrl;
+	}
+}
+
+/* API */
+/**
+ * zynq_clk_early_init() - Early init for the clock framework
+ *
+ * This function is called from before relocation and sets up the CPU clock
+ * frequency in the global data struct.
+ */
+void zynq_clk_early_init(void)
+{
+	u32 reg = readl(&slcr_base->arm_clk_ctrl);
+	u32 div = (reg & CLK_CTRL_DIV0_MASK) >> CLK_CTRL_DIV0_SHIFT;
+	u32 srcsel = (reg & CLK_CTRL_SRCSEL_MASK) >> CLK_CTRL_SRCSEL_SHIFT;
+	enum zynq_clk parent = __zynq_clk_cpu_get_parent(srcsel);
+	u32 *pllreg = clkid_2_register(parent);
+	unsigned long prate = __zynq_clk_pll_get_rate(pllreg);
+
+	if (!div)
+		div = 1;
+
+	gd->cpu_clk = DIV_ROUND_CLOSEST(prate, div);
+}
+
+/**
+ * get_uart_clk() - Get UART input frequency
+ * @dev_index:	UART ID
+ * Returns UART input clock frequency in Hz.
+ *
+ * Compared to zynq_clk_get_rate() this function is designed to work before
+ * relocation and can be called when the serial UART is set up.
+ */
+unsigned long get_uart_clk(int dev_index)
+{
+	u32 reg = readl(&slcr_base->uart_clk_ctrl);
+	u32 div = (reg & CLK_CTRL_DIV0_MASK) >> CLK_CTRL_DIV0_SHIFT;
+	u32 srcsel = (reg & CLK_CTRL_SRCSEL_MASK) >> CLK_CTRL_SRCSEL_SHIFT;
+	enum zynq_clk parent = __zynq_clk_periph_get_parent(srcsel);
+	u32 *pllreg = clkid_2_register(parent);
+	unsigned long prate = __zynq_clk_pll_get_rate(pllreg);
+
+	if (!div)
+		div = 1;
+
+	return DIV_ROUND_CLOSEST(prate, div);
+}
+
+/**
+ * set_cpu_clk_info() - Initialize clock framework
+ * Always returns zero.
+ *
+ * This function is called from common code after relocation and sets up the
+ * clock framework. The framework must not be used before this function had been
+ * called.
+ */
+int set_cpu_clk_info(void)
+{
+	zynq_clk_register_pll(&clks[armpll_clk], &slcr_base->arm_pll_ctrl,
+			      "armpll", CONFIG_ZYNQ_PS_CLK_FREQ);
+	zynq_clk_register_pll(&clks[ddrpll_clk], &slcr_base->ddr_pll_ctrl,
+			      "ddrpll", CONFIG_ZYNQ_PS_CLK_FREQ);
+	zynq_clk_register_pll(&clks[iopll_clk], &slcr_base->io_pll_ctrl,
+			      "iopll", CONFIG_ZYNQ_PS_CLK_FREQ);
+
+	init_ddr_clocks();
+	init_cpu_clocks();
+	init_periph_clocks();
+	init_aper_clocks();
+
+	return 0;
+}
+
+/**
+ * zynq_clk_get_rate() - Get clock rate
+ * @clk:	Clock identifier
+ * Returns the current clock rate of @clk on success or zero for an invalid
+ * clock id.
+ */
+unsigned long zynq_clk_get_rate(enum zynq_clk clk)
+{
+	if (clk < 0 || clk >= clk_max)
+		return 0;
+
+	return clks[clk].frequency;
+}
+
+/**
+ * zynq_clk_set_rate() - Set clock rate
+ * @clk:	Clock identifier
+ * @rate:	Requested clock rate
+ * Passes on the return value from the clock's set_rate() function or negative
+ * errno.
+ */
+int zynq_clk_set_rate(enum zynq_clk clk, unsigned long rate)
+{
+	if (clk < 0 || clk >= clk_max)
+		return -ENODEV;
+
+	if (clks[clk].ops.set_rate)
+		return clks[clk].ops.set_rate(&clks[clk], rate);
+
+	return -ENXIO;
+}
+
+/**
+ * zynq_clk_get_name() - Get clock name
+ * @clk:	Clock identifier
+ * Returns the name of @clk.
+ */
+const char *zynq_clk_get_name(enum zynq_clk clk)
+{
+	return clks[clk].name;
+}

arch/arm/cpu/armv7/zynq/cpu.c

@@ -6,6 +6,7 @@
  */
 #include <common.h>
 #include <asm/io.h>
+#include <asm/arch/clk.h>
 #include <asm/arch/sys_proto.h>
 #include <asm/arch/hardware.h>
 
@@ -35,6 +36,7 @@ int arch_cpu_init(void)
 	writel(0xC, &slcr_base->ddr_urgent);
 #endif
 
+	zynq_clk_early_init();
 	zynq_slcr_lock();
 
 	return 0;

arch/arm/include/asm/arch-zynq/clk.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2013 Xilinx Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _ZYNQ_CLK_H_
+#define _ZYNQ_CLK_H_
+
+enum zynq_clk {
+	armpll_clk, ddrpll_clk, iopll_clk,
+	cpu_6or4x_clk, cpu_3or2x_clk, cpu_2x_clk, cpu_1x_clk,
+	ddr2x_clk, ddr3x_clk, dci_clk,
+	lqspi_clk, smc_clk, pcap_clk, gem0_clk, gem1_clk,
+	fclk0_clk, fclk1_clk, fclk2_clk, fclk3_clk, can0_clk, can1_clk,
+	sdio0_clk, sdio1_clk, uart0_clk, uart1_clk, spi0_clk, spi1_clk, dma_clk,
+	usb0_aper_clk, usb1_aper_clk, gem0_aper_clk, gem1_aper_clk,
+	sdio0_aper_clk, sdio1_aper_clk, spi0_aper_clk, spi1_aper_clk,
+	can0_aper_clk, can1_aper_clk, i2c0_aper_clk, i2c1_aper_clk,
+	uart0_aper_clk, uart1_aper_clk, gpio_aper_clk, lqspi_aper_clk,
+	smc_aper_clk, swdt_clk, dbg_trc_clk, dbg_apb_clk, clk_max};
+
+void zynq_clk_early_init(void);
+int zynq_clk_set_rate(enum zynq_clk clk, unsigned long rate);
+unsigned long zynq_clk_get_rate(enum zynq_clk clk);
+const char *zynq_clk_get_name(enum zynq_clk clk);
+unsigned long get_uart_clk(int dev_id);
+
+#endif

arch/arm/include/asm/arch-zynq/hardware.h

@@ -34,12 +34,40 @@ struct slcr_regs {
 	u32 scl; /* 0x0 */
 	u32 slcr_lock; /* 0x4 */
 	u32 slcr_unlock; /* 0x8 */
-	u32 reserved0[75];
+	u32 reserved0_1[61];
+	u32 arm_pll_ctrl; /* 0x100 */
+	u32 ddr_pll_ctrl; /* 0x104 */
+	u32 io_pll_ctrl; /* 0x108 */
+	u32 reserved0_2[5];
+	u32 arm_clk_ctrl; /* 0x120 */
+	u32 ddr_clk_ctrl; /* 0x124 */
+	u32 dci_clk_ctrl; /* 0x128 */
+	u32 aper_clk_ctrl; /* 0x12c */
+	u32 reserved0_3[2];
 	u32 gem0_rclk_ctrl; /* 0x138 */
 	u32 gem1_rclk_ctrl; /* 0x13c */
 	u32 gem0_clk_ctrl; /* 0x140 */
 	u32 gem1_clk_ctrl; /* 0x144 */
-	u32 reserved1[46];
+	u32 smc_clk_ctrl; /* 0x148 */
+	u32 lqspi_clk_ctrl; /* 0x14c */
+	u32 sdio_clk_ctrl; /* 0x150 */
+	u32 uart_clk_ctrl; /* 0x154 */
+	u32 spi_clk_ctrl; /* 0x158 */
+	u32 can_clk_ctrl; /* 0x15c */
+	u32 can_mioclk_ctrl; /* 0x160 */
+	u32 dbg_clk_ctrl; /* 0x164 */
+	u32 pcap_clk_ctrl; /* 0x168 */
+	u32 reserved0_4[1];
+	u32 fpga0_clk_ctrl; /* 0x170 */
+	u32 reserved0_5[3];
+	u32 fpga1_clk_ctrl; /* 0x180 */
+	u32 reserved0_6[3];
+	u32 fpga2_clk_ctrl; /* 0x190 */
+	u32 reserved0_7[3];
+	u32 fpga3_clk_ctrl; /* 0x1a0 */
+	u32 reserved0_8[8];
+	u32 clk_621_true; /* 0x1c4 */
+	u32 reserved1[14];
 	u32 pss_rst_ctrl; /* 0x200 */
 	u32 reserved2[15];
 	u32 fpga_rst_ctrl; /* 0x240 */

include/configs/zynq-common.h

@@ -163,6 +163,7 @@
 #define CONFIG_AUTO_COMPLETE
 #define CONFIG_BOARD_LATE_INIT
 #define CONFIG_SYS_LONGHELP
+#define CONFIG_CLOCKS
 #define CONFIG_SYS_MAXARGS		15 /* max number of command args */
 #define CONFIG_SYS_CBSIZE		256 /* Console I/O Buffer Size */
 #define CONFIG_SYS_PBSIZE		(CONFIG_SYS_CBSIZE + \