/*
 *  Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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 St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <asm/clkdev.h>

#include <mach/clock.h>
#include <mach/hardware.h>
#include <mach/common.h>

#define IO_ADDR_CCM(off)	(MX1_IO_ADDRESS(MX1_CCM_BASE_ADDR + (off)))

/* CCM register addresses */
#define CCM_CSCR	IO_ADDR_CCM(0x0)
#define CCM_MPCTL0	IO_ADDR_CCM(0x4)
#define CCM_SPCTL0	IO_ADDR_CCM(0xc)
#define CCM_PCDR	IO_ADDR_CCM(0x20)

#define CCM_CSCR_CLKO_OFFSET	29
#define CCM_CSCR_CLKO_MASK	(0x7 << 29)
#define CCM_CSCR_USB_OFFSET	26
#define CCM_CSCR_USB_MASK	(0x7 << 26)
#define CCM_CSCR_OSC_EN_SHIFT	17
#define CCM_CSCR_SYSTEM_SEL	(1 << 16)
#define CCM_CSCR_BCLK_OFFSET	10
#define CCM_CSCR_BCLK_MASK	(0xf << 10)
#define CCM_CSCR_PRESC		(1 << 15)

#define CCM_PCDR_PCLK3_OFFSET	16
#define CCM_PCDR_PCLK3_MASK	(0x7f << 16)
#define CCM_PCDR_PCLK2_OFFSET	4
#define CCM_PCDR_PCLK2_MASK	(0xf << 4)
#define CCM_PCDR_PCLK1_OFFSET	0
#define CCM_PCDR_PCLK1_MASK	0xf

#define IO_ADDR_SCM(off)	(MX1_IO_ADDRESS(MX1_SCM_BASE_ADDR + (off)))

/* SCM register addresses */
#define SCM_GCCR	IO_ADDR_SCM(0xc)

#define SCM_GCCR_DMA_CLK_EN_OFFSET	3
#define SCM_GCCR_CSI_CLK_EN_OFFSET	2
#define SCM_GCCR_MMA_CLK_EN_OFFSET	1
#define SCM_GCCR_USBD_CLK_EN_OFFSET	0

static int _clk_enable(struct clk *clk)
{
	unsigned int reg;

	reg = __raw_readl(clk->enable_reg);
	reg |= 1 << clk->enable_shift;
	__raw_writel(reg, clk->enable_reg);

	return 0;
}

static void _clk_disable(struct clk *clk)
{
	unsigned int reg;

	reg = __raw_readl(clk->enable_reg);
	reg &= ~(1 << clk->enable_shift);
	__raw_writel(reg, clk->enable_reg);
}

static int _clk_can_use_parent(const struct clk *clk_arr[], unsigned int size,
			       struct clk *parent)
{
	int i;

	for (i = 0; i < size; i++)
		if (parent == clk_arr[i])
			return i;

	return -EINVAL;
}

static unsigned long
_clk_simple_round_rate(struct clk *clk, unsigned long rate, unsigned int limit)
{
	int div;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;
	if (parent_rate % rate)
		div++;

	if (div > limit)
		div = limit;

	return parent_rate / div;
}

static unsigned long _clk_parent_round_rate(struct clk *clk, unsigned long rate)
{
	return clk->parent->round_rate(clk->parent, rate);
}

static int _clk_parent_set_rate(struct clk *clk, unsigned long rate)
{
	return clk->parent->set_rate(clk->parent, rate);
}

static unsigned long clk16m_get_rate(struct clk *clk)
{
	return 16000000;
}

static struct clk clk16m = {
	.get_rate = clk16m_get_rate,
	.enable = _clk_enable,
	.enable_reg = CCM_CSCR,
	.enable_shift = CCM_CSCR_OSC_EN_SHIFT,
	.disable = _clk_disable,
};

/* in Hz */
static unsigned long clk32_rate;

static unsigned long clk32_get_rate(struct clk *clk)
{
	return clk32_rate;
}

static struct clk clk32 = {
	.get_rate = clk32_get_rate,
};

static unsigned long clk32_premult_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) * 512;
}

static struct clk clk32_premult = {
	.parent = &clk32,
	.get_rate = clk32_premult_get_rate,
};

static const struct clk *prem_clk_clocks[] = {
	&clk32_premult,
	&clk16m,
};

static int prem_clk_set_parent(struct clk *clk, struct clk *parent)
{
	int i;
	unsigned int reg = __raw_readl(CCM_CSCR);

	i = _clk_can_use_parent(prem_clk_clocks, ARRAY_SIZE(prem_clk_clocks),
				parent);

	switch (i) {
	case 0:
		reg &= ~CCM_CSCR_SYSTEM_SEL;
		break;
	case 1:
		reg |= CCM_CSCR_SYSTEM_SEL;
		break;
	default:
		return i;
	}

	__raw_writel(reg, CCM_CSCR);

	return 0;
}

static struct clk prem_clk = {
	.set_parent = prem_clk_set_parent,
};

static unsigned long system_clk_get_rate(struct clk *clk)
{
	return mxc_decode_pll(__raw_readl(CCM_SPCTL0),
			      clk_get_rate(clk->parent));
}

static struct clk system_clk = {
	.parent = &prem_clk,
	.get_rate = system_clk_get_rate,
};

static unsigned long mcu_clk_get_rate(struct clk *clk)
{
	return mxc_decode_pll(__raw_readl(CCM_MPCTL0),
			      clk_get_rate(clk->parent));
}

static struct clk mcu_clk = {
	.parent = &clk32_premult,
	.get_rate = mcu_clk_get_rate,
};

static unsigned long fclk_get_rate(struct clk *clk)
{
	unsigned long fclk = clk_get_rate(clk->parent);

	if (__raw_readl(CCM_CSCR) & CCM_CSCR_PRESC)
		fclk /= 2;

	return fclk;
}

static struct clk fclk = {
	.parent = &mcu_clk,
	.get_rate = fclk_get_rate,
};

/*
 *  get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA )
 */
static unsigned long hclk_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) / (((__raw_readl(CCM_CSCR) &
			CCM_CSCR_BCLK_MASK) >> CCM_CSCR_BCLK_OFFSET) + 1);
}

static unsigned long hclk_round_rate(struct clk *clk, unsigned long rate)
{
	return _clk_simple_round_rate(clk, rate, 16);
}

static int hclk_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned int div;
	unsigned int reg;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;

	if (div > 16 || div < 1 || ((parent_rate / div) != rate))
		return -EINVAL;

	div--;

	reg = __raw_readl(CCM_CSCR);
	reg &= ~CCM_CSCR_BCLK_MASK;
	reg |= div << CCM_CSCR_BCLK_OFFSET;
	__raw_writel(reg, CCM_CSCR);

	return 0;
}

static struct clk hclk = {
	.parent = &system_clk,
	.get_rate = hclk_get_rate,
	.round_rate = hclk_round_rate,
	.set_rate = hclk_set_rate,
};

static unsigned long clk48m_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) / (((__raw_readl(CCM_CSCR) &
			CCM_CSCR_USB_MASK) >> CCM_CSCR_USB_OFFSET) + 1);
}

static unsigned long clk48m_round_rate(struct clk *clk, unsigned long rate)
{
	return _clk_simple_round_rate(clk, rate, 8);
}

static int clk48m_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned int div;
	unsigned int reg;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;

	if (div > 8 || div < 1 || ((parent_rate / div) != rate))
		return -EINVAL;

	div--;

	reg = __raw_readl(CCM_CSCR);
	reg &= ~CCM_CSCR_USB_MASK;
	reg |= div << CCM_CSCR_USB_OFFSET;
	__raw_writel(reg, CCM_CSCR);

	return 0;
}

static struct clk clk48m = {
	.parent = &system_clk,
	.get_rate = clk48m_get_rate,
	.round_rate = clk48m_round_rate,
	.set_rate = clk48m_set_rate,
};

/*
 *  get peripheral clock 1 ( UART[12], Timer[12], PWM )
 */
static unsigned long perclk1_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
			CCM_PCDR_PCLK1_MASK) >> CCM_PCDR_PCLK1_OFFSET) + 1);
}

static unsigned long perclk1_round_rate(struct clk *clk, unsigned long rate)
{
	return _clk_simple_round_rate(clk, rate, 16);
}

static int perclk1_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned int div;
	unsigned int reg;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;

	if (div > 16 || div < 1 || ((parent_rate / div) != rate))
		return -EINVAL;

	div--;

	reg = __raw_readl(CCM_PCDR);
	reg &= ~CCM_PCDR_PCLK1_MASK;
	reg |= div << CCM_PCDR_PCLK1_OFFSET;
	__raw_writel(reg, CCM_PCDR);

	return 0;
}

/*
 *  get peripheral clock 2 ( LCD, SD, SPI[12] )
 */
static unsigned long perclk2_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
			CCM_PCDR_PCLK2_MASK) >> CCM_PCDR_PCLK2_OFFSET) + 1);
}

static unsigned long perclk2_round_rate(struct clk *clk, unsigned long rate)
{
	return _clk_simple_round_rate(clk, rate, 16);
}

static int perclk2_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned int div;
	unsigned int reg;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;

	if (div > 16 || div < 1 || ((parent_rate / div) != rate))
		return -EINVAL;

	div--;

	reg = __raw_readl(CCM_PCDR);
	reg &= ~CCM_PCDR_PCLK2_MASK;
	reg |= div << CCM_PCDR_PCLK2_OFFSET;
	__raw_writel(reg, CCM_PCDR);

	return 0;
}

/*
 *  get peripheral clock 3 ( SSI )
 */
static unsigned long perclk3_get_rate(struct clk *clk)
{
	return clk_get_rate(clk->parent) / (((__raw_readl(CCM_PCDR) &
			CCM_PCDR_PCLK3_MASK) >> CCM_PCDR_PCLK3_OFFSET) + 1);
}

static unsigned long perclk3_round_rate(struct clk *clk, unsigned long rate)
{
	return _clk_simple_round_rate(clk, rate, 128);
}

static int perclk3_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned int div;
	unsigned int reg;
	unsigned long parent_rate;

	parent_rate = clk_get_rate(clk->parent);

	div = parent_rate / rate;

	if (div > 128 || div < 1 || ((parent_rate / div) != rate))
		return -EINVAL;

	div--;

	reg = __raw_readl(CCM_PCDR);
	reg &= ~CCM_PCDR_PCLK3_MASK;
	reg |= div << CCM_PCDR_PCLK3_OFFSET;
	__raw_writel(reg, CCM_PCDR);

	return 0;
}

static struct clk perclk[] = {
	{
		.id = 0,
		.parent = &system_clk,
		.get_rate = perclk1_get_rate,
		.round_rate = perclk1_round_rate,
		.set_rate = perclk1_set_rate,
	}, {
		.id = 1,
		.parent = &system_clk,
		.get_rate = perclk2_get_rate,
		.round_rate = perclk2_round_rate,
		.set_rate = perclk2_set_rate,
	}, {
		.id = 2,
		.parent = &system_clk,
		.get_rate = perclk3_get_rate,
		.round_rate = perclk3_round_rate,
		.set_rate = perclk3_set_rate,
	}
};

static const struct clk *clko_clocks[] = {
	&perclk[0],
	&hclk,
	&clk48m,
	&clk16m,
	&prem_clk,
	&fclk,
};

static int clko_set_parent(struct clk *clk, struct clk *parent)
{
	int i;
	unsigned int reg;

	i = _clk_can_use_parent(clko_clocks, ARRAY_SIZE(clko_clocks), parent);
	if (i < 0)
		return i;

	reg = __raw_readl(CCM_CSCR) & ~CCM_CSCR_CLKO_MASK;
	reg |= i << CCM_CSCR_CLKO_OFFSET;
	__raw_writel(reg, CCM_CSCR);

	if (clko_clocks[i]->set_rate && clko_clocks[i]->round_rate) {
		clk->set_rate = _clk_parent_set_rate;
		clk->round_rate = _clk_parent_round_rate;
	} else {
		clk->set_rate = NULL;
		clk->round_rate = NULL;
	}

	return 0;
}

static struct clk clko_clk = {
	.set_parent = clko_set_parent,
};

static struct clk dma_clk = {
	.parent = &hclk,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
	.enable = _clk_enable,
	.enable_reg = SCM_GCCR,
	.enable_shift = SCM_GCCR_DMA_CLK_EN_OFFSET,
	.disable = _clk_disable,
};

static struct clk csi_clk = {
	.parent = &hclk,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
	.enable = _clk_enable,
	.enable_reg = SCM_GCCR,
	.enable_shift = SCM_GCCR_CSI_CLK_EN_OFFSET,
	.disable = _clk_disable,
};

static struct clk mma_clk = {
	.parent = &hclk,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
	.enable = _clk_enable,
	.enable_reg = SCM_GCCR,
	.enable_shift = SCM_GCCR_MMA_CLK_EN_OFFSET,
	.disable = _clk_disable,
};

static struct clk usbd_clk = {
	.parent = &clk48m,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
	.enable = _clk_enable,
	.enable_reg = SCM_GCCR,
	.enable_shift = SCM_GCCR_USBD_CLK_EN_OFFSET,
	.disable = _clk_disable,
};

static struct clk gpt_clk = {
	.parent = &perclk[0],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk uart_clk = {
	.parent = &perclk[0],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk i2c_clk = {
	.parent = &hclk,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk spi_clk = {
	.parent = &perclk[1],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk sdhc_clk = {
	.parent = &perclk[1],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk lcdc_clk = {
	.parent = &perclk[1],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk mshc_clk = {
	.parent = &hclk,
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk ssi_clk = {
	.parent = &perclk[2],
	.round_rate = _clk_parent_round_rate,
	.set_rate = _clk_parent_set_rate,
};

static struct clk rtc_clk = {
	.parent = &clk32,
};

#define _REGISTER_CLOCK(d, n, c) \
	{ \
		.dev_id = d, \
		.con_id = n, \
		.clk = &c, \
	},
static struct clk_lookup lookups[] __initdata = {
	_REGISTER_CLOCK(NULL, "dma", dma_clk)
	_REGISTER_CLOCK("mx1-camera.0", NULL, csi_clk)
	_REGISTER_CLOCK(NULL, "mma", mma_clk)
	_REGISTER_CLOCK("imx_udc.0", NULL, usbd_clk)
	_REGISTER_CLOCK(NULL, "gpt", gpt_clk)
	_REGISTER_CLOCK("imx-uart.0", NULL, uart_clk)
	_REGISTER_CLOCK("imx-uart.1", NULL, uart_clk)
	_REGISTER_CLOCK("imx-uart.2", NULL, uart_clk)
	_REGISTER_CLOCK("imx-i2c.0", NULL, i2c_clk)
	_REGISTER_CLOCK("imx1-cspi.0", NULL, spi_clk)
	_REGISTER_CLOCK("imx-mmc.0", NULL, sdhc_clk)
	_REGISTER_CLOCK("imx-fb.0", NULL, lcdc_clk)
	_REGISTER_CLOCK(NULL, "mshc", mshc_clk)
	_REGISTER_CLOCK(NULL, "ssi", ssi_clk)
	_REGISTER_CLOCK("mxc_rtc.0", NULL, rtc_clk)
};

int __init mx1_clocks_init(unsigned long fref)
{
	unsigned int reg;

	/* disable clocks we are able to */
	__raw_writel(0, SCM_GCCR);

	clk32_rate = fref;
	reg = __raw_readl(CCM_CSCR);

	/* detect clock reference for system PLL */
	if (reg & CCM_CSCR_SYSTEM_SEL) {
		prem_clk.parent = &clk16m;
	} else {
		/* ensure that oscillator is disabled */
		reg &= ~(1 << CCM_CSCR_OSC_EN_SHIFT);
		__raw_writel(reg, CCM_CSCR);
		prem_clk.parent = &clk32_premult;
	}

	/* detect reference for CLKO */
	reg = (reg & CCM_CSCR_CLKO_MASK) >> CCM_CSCR_CLKO_OFFSET;
	clko_clk.parent = (struct clk *)clko_clocks[reg];

	clkdev_add_table(lookups, ARRAY_SIZE(lookups));

	clk_enable(&hclk);
	clk_enable(&fclk);

	mxc_timer_init(&gpt_clk, MX1_IO_ADDRESS(MX1_TIM1_BASE_ADDR),
			MX1_TIM1_INT);

	return 0;
}