ARM: Add the clock framework for Telechips TCC8xxx processors.

This adds definitions and low-level functions to handle clocks in
TCC8xxx processors.

Signed-off-by: "Hans J. Koch" <hjk@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

8 files changed, 834 insertions, 11 deletions

diff --git a/arch/arm/mach-tcc8k/Makefile b/arch/arm/mach-tcc8k/Makefile
new file mode 100644
index 0000000..805d850
--- /dev/null
+++ b/arch/arm/mach-tcc8k/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for TCC8K boards and common files.
+#
+
+# Common support
+obj-y += clock.o
diff --git a/arch/arm/mach-tcc8k/clock.c b/arch/arm/mach-tcc8k/clock.c
new file mode 100644
index 0000000..a8982af
--- /dev/null
+++ b/arch/arm/mach-tcc8k/clock.c
@@ -0,0 +1,566 @@
+/*
+ * Lowlevel clock handling for Telechips TCC8xxx SoCs
+ *
+ * Copyright (C) 2010 by Hans J. Koch <hjk@linutronix.de>
+ *
+ * Licensed under the terms of the GPL v2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+
+#include <asm/clkdev.h>
+
+#include <mach/clock.h>
+#include <mach/irqs.h>
+#include <mach/tcc8k-regs.h>
+
+#include "common.h"
+
+#define BCLKCTR0	(CKC_BASE + BCLKCTR0_OFFS)
+#define BCLKCTR1	(CKC_BASE + BCLKCTR1_OFFS)
+
+#define ACLKREF		(CKC_BASE + ACLKREF_OFFS)
+#define ACLKUART0	(CKC_BASE + ACLKUART0_OFFS)
+#define ACLKUART1	(CKC_BASE + ACLKUART1_OFFS)
+#define ACLKUART2	(CKC_BASE + ACLKUART2_OFFS)
+#define ACLKUART3	(CKC_BASE + ACLKUART3_OFFS)
+#define ACLKUART4	(CKC_BASE + ACLKUART4_OFFS)
+#define ACLKI2C		(CKC_BASE + ACLKI2C_OFFS)
+#define ACLKADC		(CKC_BASE + ACLKADC_OFFS)
+#define ACLKUSBH	(CKC_BASE + ACLKUSBH_OFFS)
+#define ACLKLCD		(CKC_BASE + ACLKLCD_OFFS)
+#define ACLKSDH0	(CKC_BASE + ACLKSDH0_OFFS)
+#define ACLKSDH1	(CKC_BASE + ACLKSDH1_OFFS)
+#define ACLKSPI0	(CKC_BASE + ACLKSPI0_OFFS)
+#define ACLKSPI1	(CKC_BASE + ACLKSPI1_OFFS)
+#define ACLKSPDIF	(CKC_BASE + ACLKSPDIF_OFFS)
+#define ACLKC3DEC	(CKC_BASE + ACLKC3DEC_OFFS)
+#define ACLKCAN0	(CKC_BASE + ACLKCAN0_OFFS)
+#define ACLKCAN1	(CKC_BASE + ACLKCAN1_OFFS)
+#define ACLKGSB0	(CKC_BASE + ACLKGSB0_OFFS)
+#define ACLKGSB1	(CKC_BASE + ACLKGSB1_OFFS)
+#define ACLKGSB2	(CKC_BASE + ACLKGSB2_OFFS)
+#define ACLKGSB3	(CKC_BASE + ACLKGSB3_OFFS)
+#define ACLKUSBH	(CKC_BASE + ACLKUSBH_OFFS)
+#define ACLKTCT		(CKC_BASE + ACLKTCT_OFFS)
+#define ACLKTCX		(CKC_BASE + ACLKTCX_OFFS)
+#define ACLKTCZ		(CKC_BASE + ACLKTCZ_OFFS)
+
+/* Crystal frequencies */
+static unsigned long xi_rate, xti_rate;
+
+static void __iomem *pll_cfg_addr(int pll)
+{
+	switch (pll) {
+	case 0: return (CKC_BASE + PLL0CFG_OFFS);
+	case 1: return (CKC_BASE + PLL1CFG_OFFS);
+	case 2: return (CKC_BASE + PLL2CFG_OFFS);
+	default:
+		BUG();
+	}
+}
+
+static int pll_enable(int pll, int enable)
+{
+	u32 reg;
+	void __iomem *addr = pll_cfg_addr(pll);
+
+	reg = __raw_readl(addr);
+	if (enable)
+		reg &= ~PLLxCFG_PD;
+	else
+		reg |= PLLxCFG_PD;
+
+	__raw_writel(reg, addr);
+	return 0;
+}
+
+static int xi_enable(int enable)
+{
+	u32 reg;
+
+	reg = __raw_readl(CKC_BASE + CLKCTRL_OFFS);
+	if (enable)
+		reg |= CLKCTRL_XE;
+	else
+		reg &= ~CLKCTRL_XE;
+
+	__raw_writel(reg, CKC_BASE + CLKCTRL_OFFS);
+	return 0;
+}
+
+static int root_clk_enable(enum root_clks src)
+{
+	switch (src) {
+	case CLK_SRC_PLL0: return pll_enable(0, 1);
+	case CLK_SRC_PLL1: return pll_enable(1, 1);
+	case CLK_SRC_PLL2: return pll_enable(2, 1);
+	case CLK_SRC_XI: return xi_enable(1);
+	default:
+		BUG();
+	}
+	return 0;
+}
+
+static int root_clk_disable(enum root_clks root_src)
+{
+	switch (root_src) {
+	case CLK_SRC_PLL0: return pll_enable(0, 0);
+	case CLK_SRC_PLL1: return pll_enable(1, 0);
+	case CLK_SRC_PLL2: return pll_enable(2, 0);
+	case CLK_SRC_XI: return xi_enable(0);
+	default:
+		BUG();
+	}
+	return 0;
+}
+
+static int enable_clk(struct clk *clk)
+{
+	u32 reg;
+
+	if (clk->root_id != CLK_SRC_NOROOT)
+		return root_clk_enable(clk->root_id);
+
+	if (clk->aclkreg) {
+		reg = __raw_readl(clk->aclkreg);
+		reg |= ACLK_EN;
+		__raw_writel(reg, clk->aclkreg);
+	}
+	if (clk->bclkctr) {
+		reg = __raw_readl(clk->bclkctr);
+		reg |= 1 << clk->bclk_shift;
+		__raw_writel(reg, clk->bclkctr);
+	}
+	return 0;
+}
+
+static void disable_clk(struct clk *clk)
+{
+	u32 reg;
+
+	if (clk->root_id != CLK_SRC_NOROOT) {
+		root_clk_disable(clk->root_id);
+		return;
+	}
+
+	if (clk->bclkctr) {
+		reg = __raw_readl(clk->bclkctr);
+		reg &= ~(1 << clk->bclk_shift);
+		__raw_writel(reg, clk->bclkctr);
+	}
+	if (clk->aclkreg) {
+		reg = __raw_readl(clk->aclkreg);
+		reg &= ~ACLK_EN;
+		__raw_writel(reg, clk->aclkreg);
+	}
+}
+
+static unsigned long get_rate_pll(int pll)
+{
+	u32 reg;
+	unsigned long s, m, p;
+	void __iomem *addr = pll_cfg_addr(pll);
+
+	reg = __raw_readl(addr);
+	s = (reg >> 16) & 0x07;
+	m = (reg >> 8) & 0xff;
+	p = reg & 0x3f;
+
+	return (m * xi_rate) / (p * (1 << s));
+}
+
+static unsigned long get_rate_pll_div(int pll)
+{
+	u32 reg;
+	unsigned long div = 0;
+	void __iomem *addr;
+
+	switch (pll) {
+	case 0:
+		addr = CKC_BASE + CLKDIVC0_OFFS;
+		reg = __raw_readl(addr);
+		if (reg & CLKDIVC0_P0E)
+			div = (reg >> 24) & 0x3f;
+		break;
+	case 1:
+		addr = CKC_BASE + CLKDIVC0_OFFS;
+		reg = __raw_readl(addr);
+		if (reg & CLKDIVC0_P1E)
+			div = (reg >> 16) & 0x3f;
+		break;
+	case 2:
+		addr = CKC_BASE + CLKDIVC1_OFFS;
+		reg = __raw_readl(addr);
+		if (reg & CLKDIVC1_P2E)
+			div = __raw_readl(addr) & 0x3f;
+		break;
+	}
+	return get_rate_pll(pll) / (div + 1);
+}
+
+static unsigned long get_rate_xi_div(void)
+{
+	unsigned long div = 0;
+	u32 reg = __raw_readl(CKC_BASE + CLKDIVC0_OFFS);
+
+	if (reg & CLKDIVC0_XE)
+		div = (reg >> 8) & 0x3f;
+
+	return xi_rate / (div + 1);
+}
+
+static unsigned long get_rate_xti_div(void)
+{
+	unsigned long div = 0;
+	u32 reg = __raw_readl(CKC_BASE + CLKDIVC0_OFFS);
+
+	if (reg & CLKDIVC0_XTE)
+		div = reg & 0x3f;
+
+	return xti_rate / (div + 1);
+}
+
+static unsigned long root_clk_get_rate(enum root_clks src)
+{
+	switch (src) {
+	case CLK_SRC_PLL0: return get_rate_pll(0);
+	case CLK_SRC_PLL1: return get_rate_pll(1);
+	case CLK_SRC_PLL2: return get_rate_pll(2);
+	case CLK_SRC_PLL0DIV: return get_rate_pll_div(0);
+	case CLK_SRC_PLL1DIV: return get_rate_pll_div(1);
+	case CLK_SRC_PLL2DIV: return get_rate_pll_div(2);
+	case CLK_SRC_XI: return xi_rate;
+	case CLK_SRC_XTI: return xti_rate;
+	case CLK_SRC_XIDIV: return get_rate_xi_div();
+	case CLK_SRC_XTIDIV: return get_rate_xti_div();
+	default: return 0;
+	}
+}
+
+static unsigned long aclk_get_rate(struct clk *clk)
+{
+	u32 reg;
+	unsigned long div;
+	unsigned int src;
+
+	reg = __raw_readl(clk->aclkreg);
+	div = reg & 0x0fff;
+	src = (reg >> ACLK_SEL_SHIFT) & CLK_SRC_MASK;
+	return root_clk_get_rate(src) / (div + 1);
+}
+
+static unsigned long aclk_best_div(struct clk *clk, unsigned long rate)
+{
+	unsigned long div, src, freq, r1, r2;
+
+	src = __raw_readl(clk->aclkreg) >> ACLK_SEL_SHIFT;
+	src &= CLK_SRC_MASK;
+	freq = root_clk_get_rate(src);
+	div = freq / rate + 1;
+	r1 = freq / div;
+	r2 = freq / (div + 1);
+	if (r2 >= rate)
+		return div + 1;
+	if ((rate - r2) < (r1 - rate))
+		return div + 1;
+
+	return div;
+}
+
+static unsigned long aclk_round_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned int src;
+
+	src = __raw_readl(clk->aclkreg) >> ACLK_SEL_SHIFT;
+	src &= CLK_SRC_MASK;
+
+	return root_clk_get_rate(src) / aclk_best_div(clk, rate);
+}
+
+static int aclk_set_rate(struct clk *clk, unsigned long rate)
+{
+	u32 reg;
+
+	reg = __raw_readl(clk->aclkreg) & ~ACLK_DIV_MASK;
+	reg |= aclk_best_div(clk, rate);
+	return 0;
+}
+
+static unsigned long get_rate_sys(struct clk *clk)
+{
+	unsigned int src;
+
+	src = __raw_readl(CKC_BASE + CLKCTRL_OFFS) & CLK_SRC_MASK;
+		return root_clk_get_rate(src);
+}
+
+static unsigned long get_rate_bus(struct clk *clk)
+{
+	unsigned int div;
+
+	div = (__raw_readl(CKC_BASE + CLKCTRL_OFFS) >> 4) & 0xff;
+	return get_rate_sys(clk) / (div + 1);
+}
+
+static unsigned long get_rate_cpu(struct clk *clk)
+{
+	unsigned int reg, div, fsys, fbus;
+
+	fbus = get_rate_bus(clk);
+	reg = __raw_readl(CKC_BASE + CLKCTRL_OFFS);
+	if (reg & (1 << 29))
+		return fbus;
+	fsys = get_rate_sys(clk);
+	div = (reg >> 16) & 0x0f;
+	return fbus + ((fsys - fbus) * (div + 1)) / 16;
+}
+
+static unsigned long get_rate_root(struct clk *clk)
+{
+	return root_clk_get_rate(clk->root_id);
+}
+
+static int aclk_set_parent(struct clk *clock, struct clk *parent)
+{
+	u32 reg;
+
+	if (clock->parent == parent)
+		return 0;
+
+	clock->parent = parent;
+
+	if (!parent)
+		return 0;
+
+	if (parent->root_id == CLK_SRC_NOROOT)
+		return 0;
+	reg = __raw_readl(clock->aclkreg);
+	reg &= ~ACLK_SEL_MASK;
+	reg |= (parent->root_id << ACLK_SEL_SHIFT) & ACLK_SEL_MASK;
+	__raw_writel(reg, clock->aclkreg);
+
+	return 0;
+}
+
+#define DEFINE_ROOT_CLOCK(name, ri, p)	\
+	static struct clk name = {		\
+		.root_id = ri,			\
+		.get_rate = get_rate_root,			\
+		.enable = enable_clk,		\
+		.disable = disable_clk,		\
+		.parent = p,			\
+	};
+
+#define DEFINE_SPECIAL_CLOCK(name, gr, p)	\
+	static struct clk name = {		\
+		.root_id = CLK_SRC_NOROOT,	\
+		.get_rate = gr,			\
+		.parent = p,			\
+	};
+
+#define DEFINE_ACLOCK(name, bc, bs, ar)		\
+	static struct clk name = {		\
+		.root_id = CLK_SRC_NOROOT,	\
+		.bclkctr = bc,			\
+		.bclk_shift = bs,		\
+		.aclkreg = ar,			\
+		.get_rate = aclk_get_rate,	\
+		.set_rate = aclk_set_rate,	\
+		.round_rate = aclk_round_rate,	\
+		.enable = enable_clk,		\
+		.disable = disable_clk,		\
+		.set_parent = aclk_set_parent,	\
+	};
+
+#define DEFINE_BCLOCK(name, bc, bs, gr, p)	\
+	static struct clk name = {		\
+		.root_id = CLK_SRC_NOROOT,	\
+		.bclkctr = bc,			\
+		.bclk_shift = bs,		\
+		.get_rate = gr,			\
+		.enable = enable_clk,		\
+		.disable = disable_clk,		\
+		.parent = p,			\
+	};
+
+DEFINE_ROOT_CLOCK(xi, CLK_SRC_XI, NULL)
+DEFINE_ROOT_CLOCK(xti, CLK_SRC_XTI, NULL)
+DEFINE_ROOT_CLOCK(xidiv, CLK_SRC_XIDIV, &xi)
+DEFINE_ROOT_CLOCK(xtidiv, CLK_SRC_XTIDIV, &xti)
+DEFINE_ROOT_CLOCK(pll0, CLK_SRC_PLL0, &xi)
+DEFINE_ROOT_CLOCK(pll1, CLK_SRC_PLL1, &xi)
+DEFINE_ROOT_CLOCK(pll2, CLK_SRC_PLL2, &xi)
+DEFINE_ROOT_CLOCK(pll0div, CLK_SRC_PLL0DIV, &pll0)
+DEFINE_ROOT_CLOCK(pll1div, CLK_SRC_PLL1DIV, &pll1)
+DEFINE_ROOT_CLOCK(pll2div, CLK_SRC_PLL2DIV, &pll2)
+
+/* The following 3 clocks are special and are initialized explicitly later */
+DEFINE_SPECIAL_CLOCK(sys, get_rate_sys, NULL)
+DEFINE_SPECIAL_CLOCK(bus, get_rate_bus, &sys)
+DEFINE_SPECIAL_CLOCK(cpu, get_rate_cpu, &sys)
+
+DEFINE_ACLOCK(tct, NULL, 0, ACLKTCT)
+DEFINE_ACLOCK(tcx, NULL, 0, ACLKTCX)
+DEFINE_ACLOCK(tcz, NULL, 0, ACLKTCZ)
+DEFINE_ACLOCK(ref, NULL, 0, ACLKREF)
+DEFINE_ACLOCK(uart0, BCLKCTR0, 5, ACLKUART0)
+DEFINE_ACLOCK(uart1, BCLKCTR0, 23, ACLKUART1)
+DEFINE_ACLOCK(uart2, BCLKCTR0, 6, ACLKUART2)
+DEFINE_ACLOCK(uart3, BCLKCTR0, 8, ACLKUART3)
+DEFINE_ACLOCK(uart4, BCLKCTR1, 6, ACLKUART4)
+DEFINE_ACLOCK(i2c, BCLKCTR0, 7, ACLKI2C)
+DEFINE_ACLOCK(adc, BCLKCTR0, 10, ACLKADC)
+DEFINE_ACLOCK(usbh0, BCLKCTR0, 11, ACLKUSBH)
+DEFINE_ACLOCK(lcd, BCLKCTR0, 13, ACLKLCD)
+DEFINE_ACLOCK(sd0, BCLKCTR0, 17, ACLKSDH0)
+DEFINE_ACLOCK(sd1, BCLKCTR1, 5, ACLKSDH1)
+DEFINE_ACLOCK(spi0, BCLKCTR0, 24, ACLKSPI0)
+DEFINE_ACLOCK(spi1, BCLKCTR0, 30, ACLKSPI1)
+DEFINE_ACLOCK(spdif, BCLKCTR1, 2, ACLKSPDIF)
+DEFINE_ACLOCK(c3dec, BCLKCTR1, 9, ACLKC3DEC)
+DEFINE_ACLOCK(can0, BCLKCTR1, 10, ACLKCAN0)
+DEFINE_ACLOCK(can1, BCLKCTR1, 11, ACLKCAN1)
+DEFINE_ACLOCK(gsb0, BCLKCTR1, 13, ACLKGSB0)
+DEFINE_ACLOCK(gsb1, BCLKCTR1, 14, ACLKGSB1)
+DEFINE_ACLOCK(gsb2, BCLKCTR1, 15, ACLKGSB2)
+DEFINE_ACLOCK(gsb3, BCLKCTR1, 16, ACLKGSB3)
+DEFINE_ACLOCK(usbh1, BCLKCTR1, 20, ACLKUSBH)
+
+DEFINE_BCLOCK(dai0, BCLKCTR0, 0, NULL, NULL)
+DEFINE_BCLOCK(pic, BCLKCTR0, 1, NULL, NULL)
+DEFINE_BCLOCK(tc, BCLKCTR0, 2, NULL, NULL)
+DEFINE_BCLOCK(gpio, BCLKCTR0, 3, NULL, NULL)
+DEFINE_BCLOCK(usbd, BCLKCTR0, 4, NULL, NULL)
+DEFINE_BCLOCK(ecc, BCLKCTR0, 9, NULL, NULL)
+DEFINE_BCLOCK(gdma0, BCLKCTR0, 12, NULL, NULL)
+DEFINE_BCLOCK(rtc, BCLKCTR0, 15, NULL, NULL)
+DEFINE_BCLOCK(nfc, BCLKCTR0, 16, NULL, NULL)
+DEFINE_BCLOCK(g2d, BCLKCTR0, 18, NULL, NULL)
+DEFINE_BCLOCK(gdma1, BCLKCTR0, 22, NULL, NULL)
+DEFINE_BCLOCK(mscl, BCLKCTR0, 25, NULL, NULL)
+DEFINE_BCLOCK(bdma, BCLKCTR1, 0, NULL, NULL)
+DEFINE_BCLOCK(adma0, BCLKCTR1, 1, NULL, NULL)
+DEFINE_BCLOCK(scfg, BCLKCTR1, 3, NULL, NULL)
+DEFINE_BCLOCK(cid, BCLKCTR1, 4, NULL, NULL)
+DEFINE_BCLOCK(dai1, BCLKCTR1, 7, NULL, NULL)
+DEFINE_BCLOCK(adma1, BCLKCTR1, 8, NULL, NULL)
+DEFINE_BCLOCK(gps, BCLKCTR1, 12, NULL, NULL)
+DEFINE_BCLOCK(gdma2, BCLKCTR1, 17, NULL, NULL)
+DEFINE_BCLOCK(gdma3, BCLKCTR1, 18, NULL, NULL)
+DEFINE_BCLOCK(ddrc, BCLKCTR1, 19, NULL, NULL)
+
+#define _REGISTER_CLOCK(d, n, c) \
+	{ \
+		.dev_id = d, \
+		.con_id = n, \
+		.clk = &c, \
+	},
+
+static struct clk_lookup lookups[] = {
+	_REGISTER_CLOCK(NULL, "bus", bus)
+	_REGISTER_CLOCK(NULL, "cpu", cpu)
+	_REGISTER_CLOCK(NULL, "tct", tct)
+	_REGISTER_CLOCK(NULL, "tcx", tcx)
+	_REGISTER_CLOCK(NULL, "tcz", tcz)
+	_REGISTER_CLOCK(NULL, "ref", ref)
+	_REGISTER_CLOCK(NULL, "dai0", dai0)
+	_REGISTER_CLOCK(NULL, "pic", pic)
+	_REGISTER_CLOCK(NULL, "tc", tc)
+	_REGISTER_CLOCK(NULL, "gpio", gpio)
+	_REGISTER_CLOCK(NULL, "usbd", usbd)
+	_REGISTER_CLOCK("tcc-uart.0", NULL, uart0)
+	_REGISTER_CLOCK("tcc-uart.2", NULL, uart2)
+	_REGISTER_CLOCK("tcc-i2c", NULL, i2c)
+	_REGISTER_CLOCK("tcc-uart.3", NULL, uart3)
+	_REGISTER_CLOCK(NULL, "ecc", ecc)
+	_REGISTER_CLOCK(NULL, "adc", adc)
+	_REGISTER_CLOCK("tcc-usbh.0", "usb", usbh0)
+	_REGISTER_CLOCK(NULL, "gdma0", gdma0)
+	_REGISTER_CLOCK(NULL, "lcd", lcd)
+	_REGISTER_CLOCK(NULL, "rtc", rtc)
+	_REGISTER_CLOCK(NULL, "nfc", nfc)
+	_REGISTER_CLOCK("tcc-mmc.0", NULL, sd0)
+	_REGISTER_CLOCK(NULL, "g2d", g2d)
+	_REGISTER_CLOCK(NULL, "gdma1", gdma1)
+	_REGISTER_CLOCK("tcc-uart.1", NULL, uart1)
+	_REGISTER_CLOCK("tcc-spi.0", NULL, spi0)
+	_REGISTER_CLOCK(NULL, "mscl", mscl)
+	_REGISTER_CLOCK("tcc-spi.1", NULL, spi1)
+	_REGISTER_CLOCK(NULL, "bdma", bdma)
+	_REGISTER_CLOCK(NULL, "adma0", adma0)
+	_REGISTER_CLOCK(NULL, "spdif", spdif)
+	_REGISTER_CLOCK(NULL, "scfg", scfg)
+	_REGISTER_CLOCK(NULL, "cid", cid)
+	_REGISTER_CLOCK("tcc-mmc.1", NULL, sd1)
+	_REGISTER_CLOCK("tcc-uart.4", NULL, uart4)
+	_REGISTER_CLOCK(NULL, "dai1", dai1)
+	_REGISTER_CLOCK(NULL, "adma1", adma1)
+	_REGISTER_CLOCK(NULL, "c3dec", c3dec)
+	_REGISTER_CLOCK("tcc-can.0", NULL, can0)
+	_REGISTER_CLOCK("tcc-can.1", NULL, can1)
+	_REGISTER_CLOCK(NULL, "gps", gps)
+	_REGISTER_CLOCK("tcc-gsb.0", NULL, gsb0)
+	_REGISTER_CLOCK("tcc-gsb.1", NULL, gsb1)
+	_REGISTER_CLOCK("tcc-gsb.2", NULL, gsb2)
+	_REGISTER_CLOCK("tcc-gsb.3", NULL, gsb3)
+	_REGISTER_CLOCK(NULL, "gdma2", gdma2)
+	_REGISTER_CLOCK(NULL, "gdma3", gdma3)
+	_REGISTER_CLOCK(NULL, "ddrc", ddrc)
+	_REGISTER_CLOCK("tcc-usbh.1", "usb", usbh1)
+};
+
+static struct clk *root_clk_by_index(enum root_clks src)
+{
+	switch (src) {
+	case CLK_SRC_PLL0: return &pll0;
+	case CLK_SRC_PLL1: return &pll1;
+	case CLK_SRC_PLL2: return &pll2;
+	case CLK_SRC_PLL0DIV: return &pll0div;
+	case CLK_SRC_PLL1DIV: return &pll1div;
+	case CLK_SRC_PLL2DIV: return &pll2div;
+	case CLK_SRC_XI: return &xi;
+	case CLK_SRC_XTI: return &xti;
+	case CLK_SRC_XIDIV: return &xidiv;
+	case CLK_SRC_XTIDIV: return &xtidiv;
+	default: return NULL;
+	}
+}
+
+static void find_aclk_parent(struct clk *clk)
+{
+	unsigned int src;
+	struct clk *clock;
+
+	if (!clk->aclkreg)
+		return;
+
+	src = __raw_readl(clk->aclkreg) >> ACLK_SEL_SHIFT;
+	src &= CLK_SRC_MASK;
+
+	clock = root_clk_by_index(src);
+	if (!clock)
+		return;
+
+	clk->parent = clock;
+	clk->set_parent = aclk_set_parent;
+}
+
+void __init tcc_clocks_init(unsigned long xi_freq, unsigned long xti_freq)
+{
+	int i;
+
+	xi_rate = xi_freq;
+	xti_rate = xti_freq;
+
+	/* fixup parents and add the clock */
+	for (i = 0; i < ARRAY_SIZE(lookups); i++) {
+		find_aclk_parent(lookups[i].clk);
+		clkdev_add(&lookups[i]);
+	}
+}
diff --git a/arch/arm/mach-tcc8k/common.h b/arch/arm/mach-tcc8k/common.h
new file mode 100644
index 0000000..e2c902c
--- /dev/null
+++ b/arch/arm/mach-tcc8k/common.h
@@ -0,0 +1,6 @@
+#ifndef MACH_TCC8K_COMMON_H
+#define MACH_TCC8K_COMMON_H
+
+extern void tcc_clocks_init(unsigned long xi_freq, unsigned long xti_freq);
+
+#endif
diff --git a/arch/arm/plat-tcc/Makefile b/arch/arm/plat-tcc/Makefile
index 3f2e4fe..eceabc8 100644
--- a/arch/arm/plat-tcc/Makefile
+++ b/arch/arm/plat-tcc/Makefile
@@ -1,3 +1,3 @@
 # "Telechips Platform Common Modules"
 
-obj-y := system.o
+obj-y := clock.o system.o
diff --git a/arch/arm/plat-tcc/clock.c b/arch/arm/plat-tcc/clock.c
new file mode 100644
index 0000000..f3ced10
--- /dev/null
+++ b/arch/arm/plat-tcc/clock.c
@@ -0,0 +1,179 @@
+/*
+ * Clock framework for Telechips SoCs
+ * Based on arch/arm/plat-mxc/clock.c
+ *
+ * Copyright (C) 2004 - 2005 Nokia corporation
+ * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
+ * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
+ * Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
+ * Copyright 2010 Hans J. Koch, hjk@linutronix.de
+ *
+ * Licensed under the terms of the GPL v2.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/string.h>
+
+#include <mach/clock.h>
+#include <mach/hardware.h>
+
+static DEFINE_MUTEX(clocks_mutex);
+
+/*-------------------------------------------------------------------------
+ * Standard clock functions defined in include/linux/clk.h
+ *-------------------------------------------------------------------------*/
+
+static void __clk_disable(struct clk *clk)
+{
+	BUG_ON(clk->refcount == 0);
+
+	if (!(--clk->refcount) && clk->disable) {
+		/* Unconditionally disable the clock in hardware */
+		clk->disable(clk);
+		/* recursively disable parents */
+		if (clk->parent)
+			__clk_disable(clk->parent);
+	}
+}
+
+static int __clk_enable(struct clk *clk)
+{
+	int ret = 0;
+
+	if (clk->refcount++ == 0 && clk->enable) {
+		if (clk->parent)
+			ret = __clk_enable(clk->parent);
+		if (ret)
+			return ret;
+		else
+			return clk->enable(clk);
+	}
+
+	return 0;
+}
+
+/* This function increments the reference count on the clock and enables the
+ * clock if not already enabled. The parent clock tree is recursively enabled
+ */
+int clk_enable(struct clk *clk)
+{
+	int ret = 0;
+
+	if (!clk)
+		return -EINVAL;
+
+	mutex_lock(&clocks_mutex);
+	ret = __clk_enable(clk);
+	mutex_unlock(&clocks_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+
+/* This function decrements the reference count on the clock and disables
+ * the clock when reference count is 0. The parent clock tree is
+ * recursively disabled
+ */
+void clk_disable(struct clk *clk)
+{
+	if (!clk)
+		return;
+
+	mutex_lock(&clocks_mutex);
+	__clk_disable(clk);
+	mutex_unlock(&clocks_mutex);
+}
+EXPORT_SYMBOL_GPL(clk_disable);
+
+/* Retrieve the *current* clock rate. If the clock itself
+ * does not provide a special calculation routine, ask
+ * its parent and so on, until one is able to return
+ * a valid clock rate
+ */
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (!clk)
+		return 0UL;
+
+	if (clk->get_rate)
+		return clk->get_rate(clk);
+
+	return clk_get_rate(clk->parent);
+}
+EXPORT_SYMBOL_GPL(clk_get_rate);
+
+/* Round the requested clock rate to the nearest supported
+ * rate that is less than or equal to the requested rate.
+ * This is dependent on the clock's current parent.
+ */
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (!clk)
+		return 0;
+	if (!clk->round_rate)
+		return 0;
+
+	return clk->round_rate(clk, rate);
+}
+EXPORT_SYMBOL_GPL(clk_round_rate);
+
+/* Set the clock to the requested clock rate. The rate must
+ * match a supported rate exactly based on what clk_round_rate returns
+ */
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	int ret = -EINVAL;
+
+	if (!clk)
+		return ret;
+	if (!clk->set_rate || !rate)
+		return ret;
+
+	mutex_lock(&clocks_mutex);
+	ret = clk->set_rate(clk, rate);
+	mutex_unlock(&clocks_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_rate);
+
+/* Set the clock's parent to another clock source */
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct clk *old;
+	int ret = -EINVAL;
+
+	if (!clk)
+		return ret;
+	if (!clk->set_parent || !parent)
+		return ret;
+
+	mutex_lock(&clocks_mutex);
+	old = clk->parent;
+	if (clk->refcount)
+		__clk_enable(parent);
+	ret = clk->set_parent(clk, parent);
+	if (ret)
+		old = parent;
+	if (clk->refcount)
+		__clk_disable(old);
+	mutex_unlock(&clocks_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_parent);
+
+/* Retrieve the clock's parent clock source */
+struct clk *clk_get_parent(struct clk *clk)
+{
+	if (!clk)
+		return NULL;
+
+	return clk->parent;
+}
+EXPORT_SYMBOL_GPL(clk_get_parent);
diff --git a/arch/arm/plat-tcc/include/mach/clkdev.h b/arch/arm/plat-tcc/include/mach/clkdev.h
new file mode 100644
index 0000000..04b37a8
--- /dev/null
+++ b/arch/arm/plat-tcc/include/mach/clkdev.h
@@ -0,0 +1,7 @@
+#ifndef __ASM_MACH_CLKDEV_H
+#define __ASM_MACH_CLKDEV_H
+
+#define __clk_get(clk) ({ 1; })
+#define __clk_put(clk) do { } while (0)
+
+#endif
diff --git a/arch/arm/plat-tcc/include/mach/clock.h b/arch/arm/plat-tcc/include/mach/clock.h
new file mode 100644
index 0000000..a12f58a
--- /dev/null
+++ b/arch/arm/plat-tcc/include/mach/clock.h
@@ -0,0 +1,48 @@
+/*
+ * Low level clock header file for Telechips TCC architecture
+ * (C) 2010 Hans J. Koch <hjk@linutronix.de>
+ *
+ * Licensed under the GPL v2.
+ */
+
+#ifndef __ASM_ARCH_TCC_CLOCK_H__
+#define __ASM_ARCH_TCC_CLOCK_H__
+
+#ifndef __ASSEMBLY__
+
+struct clk {
+	struct clk *parent;
+	/* id number of a root clock, 0 for normal clocks */
+	int root_id;
+	/* Reference count of clock enable/disable */
+	int refcount;
+	/* Address of associated BCLKCTRx register. Must be set. */
+	void __iomem *bclkctr;
+	/* Bit position for BCLKCTRx. Must be set. */
+	int bclk_shift;
+	/* Address of ACLKxxx register, if any. */
+	void __iomem *aclkreg;
+	/* get the current clock rate (always a fresh value) */
+	unsigned long (*get_rate) (struct clk *);
+	/* Function ptr to set the clock to a new rate. The rate must match a
+	   supported rate returned from round_rate. Leave blank if clock is not
+	   programmable */
+	int (*set_rate) (struct clk *, unsigned long);
+	/* Function ptr to round the requested clock rate to the nearest
+	   supported rate that is less than or equal to the requested rate. */
+	unsigned long (*round_rate) (struct clk *, unsigned long);
+	/* Function ptr to enable the clock. Leave blank if clock can not
+	   be gated. */
+	int (*enable) (struct clk *);
+	/* Function ptr to disable the clock. Leave blank if clock can not
+	   be gated. */
+	void (*disable) (struct clk *);
+	/* Function ptr to set the parent clock of the clock. */
+	int (*set_parent) (struct clk *, struct clk *);
+};
+
+int clk_register(struct clk *clk);
+void clk_unregister(struct clk *clk);
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_ARCH_MXC_CLOCK_H__ */
diff --git a/arch/arm/plat-tcc/include/mach/tcc8k-regs.h b/arch/arm/plat-tcc/include/mach/tcc8k-regs.h
index f3243eb..1d94282 100644
--- a/arch/arm/plat-tcc/include/mach/tcc8k-regs.h
+++ b/arch/arm/plat-tcc/include/mach/tcc8k-regs.h
@@ -30,13 +30,13 @@
 #define EXT_MEM_CTRL_BASE	0xf0000000
 #define EXT_MEM_CTRL_SIZE	SZ_4K
 
-#define CS1_BASE_VIRT		0xf7000000
-#define AHB_PERI_BASE_VIRT	0xf4000000
-#define APB0_PERI_BASE_VIRT	0xf1000000
-#define APB1_PERI_BASE_VIRT	0xf2000000
-#define EXT_MEM_CTRL_BASE_VIRT	0xf3000000
-#define INT_SRAM_BASE_VIRT	0xf5000000
-#define DATA_TCM_BASE_VIRT	0xf6000000
+#define CS1_BASE_VIRT		(void __iomem *)0xf7000000
+#define AHB_PERI_BASE_VIRT	(void __iomem *)0xf4000000
+#define APB0_PERI_BASE_VIRT	(void __iomem *)0xf1000000
+#define APB1_PERI_BASE_VIRT	(void __iomem *)0xf2000000
+#define EXT_MEM_CTRL_BASE_VIRT	(void __iomem *)0xf3000000
+#define INT_SRAM_BASE_VIRT	(void __iomem *)0xf5000000
+#define DATA_TCM_BASE_VIRT	(void __iomem *)0xf6000000
 
 #define __REG(x)     (*((volatile u32 *)(x)))
 
@@ -649,8 +649,7 @@
 #define PMGPIO_APB_OFFS		0x800
 
 /* Clock controller registers */
-#define CKC_BASE		(APB1_PERI_BASE_VIRT + 0x6000)
-#define CKC_BASE_PHYS		(APB1_PERI_BASE + 0x6000)
+#define CKC_BASE	((void __iomem *)(APB1_PERI_BASE_VIRT + 0x6000))
 
 #define CLKCTRL_OFFS		0x00
 #define PLL0CFG_OFFS		0x04
@@ -724,8 +723,20 @@
 /* SWRESET1 bits */
 #define SWRESET1_USBH1		(1 << 20)
 
-/* System clock sources */
+/* System clock sources.
+ * Note: These are the clock sources that serve as parents for
+ * all other clocks. They have no parents themselves.
+ *
+ * These values are used for struct clk->root_id. All clocks
+ * that are not system clock sources have this value set to
+ * CLK_SRC_NOROOT.
+ * The values for system clocks start with CLK_SRC_PLL0 == 0
+ * because this gives us exactly the values needed for the lower
+ * 4 bits of ACLK_* registers. Therefore, CLK_SRC_NOROOT is
+ * defined as -1 to not disturb the order.
+ */
 enum root_clks {
+	CLK_SRC_NOROOT = -1,
 	CLK_SRC_PLL0 = 0,
 	CLK_SRC_PLL1,
 	CLK_SRC_PLL0DIV,