u-boot/arch/arm/cpu/armv7/exynos/clock.c

/*
 * Copyright (C) 2010 Samsung Electronics
 * Minkyu Kang <mk7.kang@samsung.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <common.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/clk.h>

#ifndef CONFIG_SYS_CLK_FREQ_C210
#define CONFIG_SYS_CLK_FREQ_C210	24000000
#endif

/* exynos4: return pll clock frequency */
static unsigned long exynos4_get_pll_clk(int pllreg)
{
	struct exynos4_clock *clk =
		(struct exynos4_clock *)samsung_get_base_clock();
	unsigned long r, m, p, s, k = 0, mask, fout;
	unsigned int freq;

	switch (pllreg) {
	case APLL:
		r = readl(&clk->apll_con0);
		break;
	case MPLL:
		r = readl(&clk->mpll_con0);
		break;
	case EPLL:
		r = readl(&clk->epll_con0);
		k = readl(&clk->epll_con1);
		break;
	case VPLL:
		r = readl(&clk->vpll_con0);
		k = readl(&clk->vpll_con1);
		break;
	default:
		printf("Unsupported PLL (%d)\n", pllreg);
		return 0;
	}

	/*
	 * APLL_CON: MIDV [25:16]
	 * MPLL_CON: MIDV [25:16]
	 * EPLL_CON: MIDV [24:16]
	 * VPLL_CON: MIDV [24:16]
	 */
	if (pllreg == APLL || pllreg == MPLL)
		mask = 0x3ff;
	else
		mask = 0x1ff;

	m = (r >> 16) & mask;

	/* PDIV [13:8] */
	p = (r >> 8) & 0x3f;
	/* SDIV [2:0] */
	s = r & 0x7;

	freq = CONFIG_SYS_CLK_FREQ_C210;

	if (pllreg == EPLL) {
		k = k & 0xffff;
		/* FOUT = (MDIV + K / 65536) * FIN / (PDIV * 2^SDIV) */
		fout = (m + k / 65536) * (freq / (p * (1 << s)));
	} else if (pllreg == VPLL) {
		k = k & 0xfff;
		/* FOUT = (MDIV + K / 1024) * FIN / (PDIV * 2^SDIV) */
		fout = (m + k / 1024) * (freq / (p * (1 << s)));
	} else {
		if (s < 1)
			s = 1;
		/* FOUT = MDIV * FIN / (PDIV * 2^(SDIV - 1)) */
		fout = m * (freq / (p * (1 << (s - 1))));
	}

	return fout;
}

/* exynos4: return ARM clock frequency */
static unsigned long exynos4_get_arm_clk(void)
{
	struct exynos4_clock *clk =
		(struct exynos4_clock *)samsung_get_base_clock();
	unsigned long div;
	unsigned long dout_apll;
	unsigned int apll_ratio;

	div = readl(&clk->div_cpu0);

	/* APLL_RATIO: [26:24] */
	apll_ratio = (div >> 24) & 0x7;

	dout_apll = get_pll_clk(APLL) / (apll_ratio + 1);

	return dout_apll;
}

/* exynos4: return pwm clock frequency */
static unsigned long exynos4_get_pwm_clk(void)
{
	struct exynos4_clock *clk =
		(struct exynos4_clock *)samsung_get_base_clock();
	unsigned long pclk, sclk;
	unsigned int sel;
	unsigned int ratio;

	if (s5p_get_cpu_rev() == 0) {
		/*
		 * CLK_SRC_PERIL0
		 * PWM_SEL [27:24]
		 */
		sel = readl(&clk->src_peril0);
		sel = (sel >> 24) & 0xf;

		if (sel == 0x6)
			sclk = get_pll_clk(MPLL);
		else if (sel == 0x7)
			sclk = get_pll_clk(EPLL);
		else if (sel == 0x8)
			sclk = get_pll_clk(VPLL);
		else
			return 0;

		/*
		 * CLK_DIV_PERIL3
		 * PWM_RATIO [3:0]
		 */
		ratio = readl(&clk->div_peril3);
		ratio = ratio & 0xf;
	} else if (s5p_get_cpu_rev() == 1) {
		sclk = get_pll_clk(MPLL);
		ratio = 8;
	} else
		return 0;

	pclk = sclk / (ratio + 1);

	return pclk;
}

/* exynos4: return uart clock frequency */
static unsigned long exynos4_get_uart_clk(int dev_index)
{
	struct exynos4_clock *clk =
		(struct exynos4_clock *)samsung_get_base_clock();
	unsigned long uclk, sclk;
	unsigned int sel;
	unsigned int ratio;

	/*
	 * CLK_SRC_PERIL0
	 * UART0_SEL [3:0]
	 * UART1_SEL [7:4]
	 * UART2_SEL [8:11]
	 * UART3_SEL [12:15]
	 * UART4_SEL [16:19]
	 * UART5_SEL [23:20]
	 */
	sel = readl(&clk->src_peril0);
	sel = (sel >> (dev_index << 2)) & 0xf;

	if (sel == 0x6)
		sclk = get_pll_clk(MPLL);
	else if (sel == 0x7)
		sclk = get_pll_clk(EPLL);
	else if (sel == 0x8)
		sclk = get_pll_clk(VPLL);
	else
		return 0;

	/*
	 * CLK_DIV_PERIL0
	 * UART0_RATIO [3:0]
	 * UART1_RATIO [7:4]
	 * UART2_RATIO [8:11]
	 * UART3_RATIO [12:15]
	 * UART4_RATIO [16:19]
	 * UART5_RATIO [23:20]
	 */
	ratio = readl(&clk->div_peril0);
	ratio = (ratio >> (dev_index << 2)) & 0xf;

	uclk = sclk / (ratio + 1);

	return uclk;
}

/* exynos4: set the mmc clock */
static void exynos4_set_mmc_clk(int dev_index, unsigned int div)
{
	struct exynos4_clock *clk =
		(struct exynos4_clock *)samsung_get_base_clock();
	unsigned int addr;
	unsigned int val;

	/*
	 * CLK_DIV_FSYS1
	 * MMC0_PRE_RATIO [15:8], MMC1_PRE_RATIO [31:24]
	 * CLK_DIV_FSYS2
	 * MMC2_PRE_RATIO [15:8], MMC3_PRE_RATIO [31:24]
	 */
	if (dev_index < 2) {
		addr = (unsigned int)&clk->div_fsys1;
	} else {
		addr = (unsigned int)&clk->div_fsys2;
		dev_index -= 2;
	}

	val = readl(addr);
	val &= ~(0xff << ((dev_index << 4) + 8));
	val |= (div & 0xff) << ((dev_index << 4) + 8);
	writel(val, addr);
}

unsigned long get_pll_clk(int pllreg)
{
	return exynos4_get_pll_clk(pllreg);
}

unsigned long get_arm_clk(void)
{
	return exynos4_get_arm_clk();
}

unsigned long get_pwm_clk(void)
{
	return exynos4_get_pwm_clk();
}

unsigned long get_uart_clk(int dev_index)
{
	return exynos4_get_uart_clk(dev_index);
}

void set_mmc_clk(int dev_index, unsigned int div)
{
	exynos4_set_mmc_clk(dev_index, div);
}