ARM: mxs: Add clock support

Add clock for MXS-based SoCs, MX23 and MX28.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

1 files changed, 526 insertions, 0 deletions

diff --git a/arch/arm/mach-mxs/clock-mx23.c b/arch/arm/mach-mxs/clock-mx23.c
new file mode 100644
index 000000000000..8f5a19ab558c
--- /dev/null
+++ b/arch/arm/mach-mxs/clock-mx23.c
@@ -0,0 +1,526 @@
+/*
+ * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+
+#include <asm/clkdev.h>
+#include <asm/div64.h>
+
+#include <mach/mx23.h>
+#include <mach/common.h>
+#include <mach/clock.h>
+
+#include "regs-clkctrl-mx23.h"
+
+#define CLKCTRL_BASE_ADDR	MX23_IO_ADDRESS(MX23_CLKCTRL_BASE_ADDR)
+#define DIGCTRL_BASE_ADDR	MX23_IO_ADDRESS(MX23_DIGCTL_BASE_ADDR)
+
+#define PARENT_RATE_SHIFT	8
+
+static int _raw_clk_enable(struct clk *clk)
+{
+	u32 reg;
+
+	if (clk->enable_reg) {
+		reg = __raw_readl(clk->enable_reg);
+		reg &= ~(1 << clk->enable_shift);
+		__raw_writel(reg, clk->enable_reg);
+	}
+
+	return 0;
+}
+
+static void _raw_clk_disable(struct clk *clk)
+{
+	u32 reg;
+
+	if (clk->enable_reg) {
+		reg = __raw_readl(clk->enable_reg);
+		reg |= 1 << clk->enable_shift;
+		__raw_writel(reg, clk->enable_reg);
+	}
+}
+
+/*
+ * ref_xtal_clk
+ */
+static unsigned long ref_xtal_clk_get_rate(struct clk *clk)
+{
+	return 24000000;
+}
+
+static struct clk ref_xtal_clk = {
+	.get_rate = ref_xtal_clk_get_rate,
+};
+
+/*
+ * pll_clk
+ */
+static unsigned long pll_clk_get_rate(struct clk *clk)
+{
+	return 480000000;
+}
+
+static int pll_clk_enable(struct clk *clk)
+{
+	__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
+			BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_SET);
+
+	/* Only a 10us delay is need. PLLCTRL1 LOCK bitfied is only a timer
+	 * and is incorrect (excessive). Per definition of the PLLCTRL0
+	 * POWER field, waiting at least 10us.
+	 */
+	udelay(10);
+
+	return 0;
+}
+
+static void pll_clk_disable(struct clk *clk)
+{
+	__raw_writel(BM_CLKCTRL_PLLCTRL0_POWER |
+			BM_CLKCTRL_PLLCTRL0_EN_USB_CLKS,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_PLLCTRL0_CLR);
+}
+
+static struct clk pll_clk = {
+	 .get_rate = pll_clk_get_rate,
+	 .enable = pll_clk_enable,
+	 .disable = pll_clk_disable,
+	 .parent = &ref_xtal_clk,
+};
+
+/*
+ * ref_clk
+ */
+#define _CLK_GET_RATE_REF(name, sr, ss)					\
+static unsigned long name##_get_rate(struct clk *clk)			\
+{									\
+	unsigned long parent_rate;					\
+	u32 reg, div;							\
+									\
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##sr);		\
+	div = (reg >> BP_CLKCTRL_##sr##_##ss##FRAC) & 0x3f;		\
+	parent_rate = clk_get_rate(clk->parent);			\
+									\
+	return SH_DIV((parent_rate >> PARENT_RATE_SHIFT) * 18,		\
+			div, PARENT_RATE_SHIFT);			\
+}
+
+_CLK_GET_RATE_REF(ref_cpu_clk, FRAC, CPU)
+_CLK_GET_RATE_REF(ref_emi_clk, FRAC, EMI)
+_CLK_GET_RATE_REF(ref_pix_clk, FRAC, PIX)
+_CLK_GET_RATE_REF(ref_io_clk, FRAC, IO)
+
+#define _DEFINE_CLOCK_REF(name, er, es)					\
+	static struct clk name = {					\
+		.enable_reg	= CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er,	\
+		.enable_shift	= BP_CLKCTRL_##er##_CLKGATE##es,	\
+		.get_rate	= name##_get_rate,			\
+		.enable		= _raw_clk_enable,			\
+		.disable	= _raw_clk_disable,			\
+		.parent		= &pll_clk,				\
+	}
+
+_DEFINE_CLOCK_REF(ref_cpu_clk, FRAC, CPU);
+_DEFINE_CLOCK_REF(ref_emi_clk, FRAC, EMI);
+_DEFINE_CLOCK_REF(ref_pix_clk, FRAC, PIX);
+_DEFINE_CLOCK_REF(ref_io_clk, FRAC, IO);
+
+/*
+ * General clocks
+ *
+ * clk_get_rate
+ */
+static unsigned long rtc_clk_get_rate(struct clk *clk)
+{
+	/* ref_xtal_clk is implemented as the only parent */
+	return clk_get_rate(clk->parent) / 768;
+}
+
+static unsigned long clk32k_clk_get_rate(struct clk *clk)
+{
+	return clk->parent->get_rate(clk->parent) / 750;
+}
+
+#define _CLK_GET_RATE(name, rs)						\
+static unsigned long name##_get_rate(struct clk *clk)			\
+{									\
+	u32 reg, div;							\
+									\
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
+									\
+	if (clk->parent == &ref_xtal_clk)				\
+		div = (reg & BM_CLKCTRL_##rs##_DIV_XTAL) >>		\
+			BP_CLKCTRL_##rs##_DIV_XTAL;			\
+	else								\
+		div = (reg & BM_CLKCTRL_##rs##_DIV_##rs) >>		\
+			BP_CLKCTRL_##rs##_DIV_##rs;			\
+									\
+	if (!div)							\
+		return -EINVAL;						\
+									\
+	return clk_get_rate(clk->parent) / div;				\
+}
+
+_CLK_GET_RATE(cpu_clk, CPU)
+_CLK_GET_RATE(emi_clk, EMI)
+
+#define _CLK_GET_RATE1(name, rs)					\
+static unsigned long name##_get_rate(struct clk *clk)			\
+{									\
+	u32 reg, div;							\
+									\
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs);		\
+	div = (reg & BM_CLKCTRL_##rs##_DIV) >> BP_CLKCTRL_##rs##_DIV;	\
+									\
+	if (!div)							\
+		return -EINVAL;						\
+									\
+	return clk_get_rate(clk->parent) / div;				\
+}
+
+_CLK_GET_RATE1(hbus_clk, HBUS)
+_CLK_GET_RATE1(xbus_clk, XBUS)
+_CLK_GET_RATE1(ssp_clk, SSP)
+_CLK_GET_RATE1(gpmi_clk, GPMI)
+_CLK_GET_RATE1(lcdif_clk, PIX)
+
+#define _CLK_GET_RATE_STUB(name)					\
+static unsigned long name##_get_rate(struct clk *clk)			\
+{									\
+	return clk_get_rate(clk->parent);				\
+}
+
+_CLK_GET_RATE_STUB(uart_clk)
+_CLK_GET_RATE_STUB(audio_clk)
+_CLK_GET_RATE_STUB(pwm_clk)
+
+/*
+ * clk_set_rate
+ */
+static int cpu_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	u32 reg, bm_busy, div_max, d, f, div, frac;
+	unsigned long diff, parent_rate, calc_rate;
+	int i;
+
+	parent_rate = clk_get_rate(clk->parent);
+
+	if (clk->parent == &ref_xtal_clk) {
+		div_max = BM_CLKCTRL_CPU_DIV_XTAL >> BP_CLKCTRL_CPU_DIV_XTAL;
+		bm_busy = BM_CLKCTRL_CPU_BUSY_REF_XTAL;
+		div = DIV_ROUND_UP(parent_rate, rate);
+		if (div == 0 || div > div_max)
+			return -EINVAL;
+	} else {
+		div_max = BM_CLKCTRL_CPU_DIV_CPU >> BP_CLKCTRL_CPU_DIV_CPU;
+		bm_busy = BM_CLKCTRL_CPU_BUSY_REF_CPU;
+		rate >>= PARENT_RATE_SHIFT;
+		parent_rate >>= PARENT_RATE_SHIFT;
+		diff = parent_rate;
+		div = frac = 1;
+		for (d = 1; d <= div_max; d++) {
+			f = parent_rate * 18 / d / rate;
+			if ((parent_rate * 18 / d) % rate)
+				f++;
+			if (f < 18 || f > 35)
+				continue;
+
+			calc_rate = parent_rate * 18 / f / d;
+			if (calc_rate > rate)
+				continue;
+
+			if (rate - calc_rate < diff) {
+				frac = f;
+				div = d;
+				diff = rate - calc_rate;
+			}
+
+			if (diff == 0)
+				break;
+		}
+
+		if (diff == parent_rate)
+			return -EINVAL;
+
+		reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
+		reg &= ~BM_CLKCTRL_FRAC_CPUFRAC;
+		reg |= frac;
+		__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
+	}
+
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
+	reg &= ~BM_CLKCTRL_CPU_DIV_CPU;
+	reg |= div << BP_CLKCTRL_CPU_DIV_CPU;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
+
+	for (i = 10000; i; i--)
+		if (!(__raw_readl(CLKCTRL_BASE_ADDR +
+					HW_CLKCTRL_CPU) & bm_busy))
+			break;
+	if (!i)	{
+		pr_err("%s: divider writing timeout\n", __func__);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+#define _CLK_SET_RATE(name, dr)						\
+static int name##_set_rate(struct clk *clk, unsigned long rate)		\
+{									\
+	u32 reg, div_max, div;						\
+	unsigned long parent_rate;					\
+	int i;								\
+									\
+	parent_rate = clk_get_rate(clk->parent);			\
+	div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV;	\
+									\
+	div = DIV_ROUND_UP(parent_rate, rate);				\
+	if (div == 0 || div > div_max)					\
+		return -EINVAL;						\
+									\
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr);		\
+	reg &= ~BM_CLKCTRL_##dr##_DIV;					\
+	reg |= div << BP_CLKCTRL_##dr##_DIV;				\
+	if (reg | (1 << clk->enable_shift)) {				\
+		pr_err("%s: clock is gated\n", __func__);		\
+		return -EINVAL;						\
+	}								\
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr);		\
+									\
+	for (i = 10000; i; i--)						\
+		if (!(__raw_readl(CLKCTRL_BASE_ADDR +			\
+			HW_CLKCTRL_##dr) & BM_CLKCTRL_##dr##_BUSY))	\
+			break;						\
+	if (!i)	{							\
+		pr_err("%s: divider writing timeout\n", __func__);	\
+		return -ETIMEDOUT;					\
+	}								\
+									\
+	return 0;							\
+}
+
+_CLK_SET_RATE(xbus_clk, XBUS)
+_CLK_SET_RATE(ssp_clk, SSP)
+_CLK_SET_RATE(gpmi_clk, GPMI)
+_CLK_SET_RATE(lcdif_clk, PIX)
+
+#define _CLK_SET_RATE_STUB(name)					\
+static int name##_set_rate(struct clk *clk, unsigned long rate)		\
+{									\
+	return -EINVAL;							\
+}
+
+_CLK_SET_RATE_STUB(emi_clk)
+_CLK_SET_RATE_STUB(uart_clk)
+_CLK_SET_RATE_STUB(audio_clk)
+_CLK_SET_RATE_STUB(pwm_clk)
+_CLK_SET_RATE_STUB(clk32k_clk)
+
+/*
+ * clk_set_parent
+ */
+#define _CLK_SET_PARENT(name, bit)					\
+static int name##_set_parent(struct clk *clk, struct clk *parent)	\
+{									\
+	if (parent != clk->parent) {					\
+		__raw_writel(BM_CLKCTRL_CLKSEQ_BYPASS_##bit,		\
+			 HW_CLKCTRL_CLKSEQ_TOG);			\
+		clk->parent = parent;					\
+	}								\
+									\
+	return 0;							\
+}
+
+_CLK_SET_PARENT(cpu_clk, CPU)
+_CLK_SET_PARENT(emi_clk, EMI)
+_CLK_SET_PARENT(ssp_clk, SSP)
+_CLK_SET_PARENT(gpmi_clk, GPMI)
+_CLK_SET_PARENT(lcdif_clk, PIX)
+
+#define _CLK_SET_PARENT_STUB(name)					\
+static int name##_set_parent(struct clk *clk, struct clk *parent)	\
+{									\
+	if (parent != clk->parent)					\
+		return -EINVAL;						\
+	else								\
+		return 0;						\
+}
+
+_CLK_SET_PARENT_STUB(uart_clk)
+_CLK_SET_PARENT_STUB(audio_clk)
+_CLK_SET_PARENT_STUB(pwm_clk)
+_CLK_SET_PARENT_STUB(clk32k_clk)
+
+/*
+ * clk definition
+ */
+static struct clk cpu_clk = {
+	.get_rate = cpu_clk_get_rate,
+	.set_rate = cpu_clk_set_rate,
+	.set_parent = cpu_clk_set_parent,
+	.parent = &ref_cpu_clk,
+};
+
+static struct clk hbus_clk = {
+	.get_rate = hbus_clk_get_rate,
+	.parent = &cpu_clk,
+};
+
+static struct clk xbus_clk = {
+	.get_rate = xbus_clk_get_rate,
+	.set_rate = xbus_clk_set_rate,
+	.parent = &ref_xtal_clk,
+};
+
+static struct clk rtc_clk = {
+	.get_rate = rtc_clk_get_rate,
+	.parent = &ref_xtal_clk,
+};
+
+/* usb_clk gate is controlled in DIGCTRL other than CLKCTRL */
+static struct clk usb_clk = {
+	.enable_reg = DIGCTRL_BASE_ADDR,
+	.enable_shift = 2,
+	.enable = _raw_clk_enable,
+	.disable = _raw_clk_disable,
+	.parent = &pll_clk,
+};
+
+#define _DEFINE_CLOCK(name, er, es, p)					\
+	static struct clk name = {					\
+		.enable_reg	= CLKCTRL_BASE_ADDR + HW_CLKCTRL_##er,	\
+		.enable_shift	= BP_CLKCTRL_##er##_##es,		\
+		.get_rate	= name##_get_rate,			\
+		.set_rate	= name##_set_rate,			\
+		.set_parent	= name##_set_parent,			\
+		.enable		= _raw_clk_enable,			\
+		.disable	= _raw_clk_disable,			\
+		.parent		= p,					\
+	}
+
+_DEFINE_CLOCK(emi_clk, EMI, CLKGATE, &ref_xtal_clk);
+_DEFINE_CLOCK(ssp_clk, SSP, CLKGATE, &ref_xtal_clk);
+_DEFINE_CLOCK(gpmi_clk, GPMI, CLKGATE, &ref_xtal_clk);
+_DEFINE_CLOCK(lcdif_clk, PIX, CLKGATE, &ref_xtal_clk);
+_DEFINE_CLOCK(uart_clk, XTAL, UART_CLK_GATE, &ref_xtal_clk);
+_DEFINE_CLOCK(audio_clk, XTAL, FILT_CLK24M_GATE, &ref_xtal_clk);
+_DEFINE_CLOCK(pwm_clk, XTAL, PWM_CLK24M_GATE, &ref_xtal_clk);
+_DEFINE_CLOCK(clk32k_clk, XTAL, TIMROT_CLK32K_GATE, &ref_xtal_clk);
+
+#define _REGISTER_CLOCK(d, n, c) \
+	{ \
+		.dev_id = d, \
+		.con_id = n, \
+		.clk = &c, \
+	},
+
+static struct clk_lookup lookups[] = {
+	_REGISTER_CLOCK("mxs-duart.0", NULL, uart_clk)
+	_REGISTER_CLOCK("rtc", NULL, rtc_clk)
+	_REGISTER_CLOCK(NULL, "hclk", hbus_clk)
+	_REGISTER_CLOCK(NULL, "xclk", xbus_clk)
+	_REGISTER_CLOCK(NULL, "usb", usb_clk)
+	_REGISTER_CLOCK(NULL, "audio", audio_clk)
+	_REGISTER_CLOCK(NULL, "pwm", pwm_clk)
+};
+
+static int clk_misc_init(void)
+{
+	u32 reg;
+	int i;
+
+	/* Fix up parent per register setting */
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ);
+	cpu_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_CPU) ?
+			&ref_xtal_clk : &ref_cpu_clk;
+	emi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_EMI) ?
+			&ref_xtal_clk : &ref_emi_clk;
+	ssp_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_SSP) ?
+			&ref_xtal_clk : &ref_io_clk;
+	gpmi_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_GPMI) ?
+			&ref_xtal_clk : &ref_io_clk;
+	lcdif_clk.parent = (reg & BM_CLKCTRL_CLKSEQ_BYPASS_PIX) ?
+			&ref_xtal_clk : &ref_pix_clk;
+
+	/* Use int div over frac when both are available */
+	__raw_writel(BM_CLKCTRL_CPU_DIV_XTAL_FRAC_EN,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
+	__raw_writel(BM_CLKCTRL_CPU_DIV_CPU_FRAC_EN,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_CLR);
+	__raw_writel(BM_CLKCTRL_HBUS_DIV_FRAC_EN,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS_CLR);
+
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
+	reg &= ~BM_CLKCTRL_XBUS_DIV_FRAC_EN;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_XBUS);
+
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
+	reg &= ~BM_CLKCTRL_SSP_DIV_FRAC_EN;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_SSP);
+
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
+	reg &= ~BM_CLKCTRL_GPMI_DIV_FRAC_EN;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_GPMI);
+
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
+	reg &= ~BM_CLKCTRL_PIX_DIV_FRAC_EN;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_PIX);
+
+	/*
+	 * Set safe hbus clock divider. A divider of 3 ensure that
+	 * the Vddd voltage required for the cpu clock is sufficiently
+	 * high for the hbus clock.
+	 */
+	reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
+	reg &= BM_CLKCTRL_HBUS_DIV;
+	reg |= 3 << BP_CLKCTRL_HBUS_DIV;
+	__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
+
+	for (i = 10000; i; i--)
+		if (!(__raw_readl(CLKCTRL_BASE_ADDR +
+			HW_CLKCTRL_HBUS) & BM_CLKCTRL_HBUS_BUSY))
+			break;
+	if (!i) {
+		pr_err("%s: divider writing timeout\n", __func__);
+		return -ETIMEDOUT;
+	}
+
+	/* Gate off cpu clock in WFI for power saving */
+	__raw_writel(BM_CLKCTRL_CPU_INTERRUPT_WAIT,
+			CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU_SET);
+
+	return 0;
+}
+
+int __init mx23_clocks_init(void)
+{
+	clk_misc_init();
+
+	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
+
+	mxs_timer_init(&clk32k_clk, MX23_INT_TIMER0);
+
+	return 0;
+}