/*
 * Copyright (C) 2016 BayLibre, SAS
 * Author: Neil Armstrong <narmstrong@baylibre.com>
 * Copyright (C) 2015 Amlogic, 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <drm/drmP.h>
#include "meson_drv.h"
#include "meson_vclk.h"

/*
 * VCLK is the "Pixel Clock" frequency generator from a dedicated PLL.
 * We handle the following encodings :
 * - CVBS 27MHz generator via the VCLK2 to the VENCI and VDAC blocks
 *
 * What is missing :
 * - HDMI Pixel Clocks generation
 */

/* HHI Registers */
#define HHI_VID_PLL_CLK_DIV	0x1a0 /* 0x68 offset in data sheet */
#define VID_PLL_EN		BIT(19)
#define VID_PLL_BYPASS		BIT(18)
#define VID_PLL_PRESET		BIT(15)
#define HHI_VIID_CLK_DIV	0x128 /* 0x4a offset in data sheet */
#define VCLK2_DIV_MASK		0xff
#define VCLK2_DIV_EN		BIT(16)
#define VCLK2_DIV_RESET		BIT(17)
#define CTS_VDAC_SEL_MASK	(0xf << 28)
#define CTS_VDAC_SEL_SHIFT	28
#define HHI_VIID_CLK_CNTL	0x12c /* 0x4b offset in data sheet */
#define VCLK2_EN		BIT(19)
#define VCLK2_SEL_MASK		(0x7 << 16)
#define VCLK2_SEL_SHIFT		16
#define VCLK2_SOFT_RESET	BIT(15)
#define VCLK2_DIV1_EN		BIT(0)
#define HHI_VID_CLK_DIV		0x164 /* 0x59 offset in data sheet */
#define CTS_ENCI_SEL_MASK	(0xf << 28)
#define CTS_ENCI_SEL_SHIFT	28
#define HHI_VID_CLK_CNTL2	0x194 /* 0x65 offset in data sheet */
#define CTS_ENCI_EN		BIT(0)
#define CTS_VDAC_EN		BIT(4)

#define HHI_VDAC_CNTL0		0x2F4 /* 0xbd offset in data sheet */
#define HHI_VDAC_CNTL1		0x2F8 /* 0xbe offset in data sheet */

#define HHI_HDMI_PLL_CNTL	0x320 /* 0xc8 offset in data sheet */
#define HHI_HDMI_PLL_CNTL2	0x324 /* 0xc9 offset in data sheet */
#define HHI_HDMI_PLL_CNTL3	0x328 /* 0xca offset in data sheet */
#define HHI_HDMI_PLL_CNTL4	0x32C /* 0xcb offset in data sheet */
#define HHI_HDMI_PLL_CNTL5	0x330 /* 0xcc offset in data sheet */
#define HHI_HDMI_PLL_CNTL6	0x334 /* 0xcd offset in data sheet */

#define HDMI_PLL_RESET		BIT(28)
#define HDMI_PLL_LOCK		BIT(31)

/*
 * Setup VCLK2 for 27MHz, and enable clocks for ENCI and VDAC
 *
 * TOFIX: Refactor into table to also handle HDMI frequency and paths
 */
static void meson_venci_cvbs_clock_config(struct meson_drm *priv)
{
	unsigned int val;

	/* Setup PLL to output 1.485GHz */
	if (meson_vpu_is_compatible(priv, "amlogic,meson-gxbb-vpu")) {
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x5800023d);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL2, 0x00404e00);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL3, 0x0d5c5091);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL4, 0x801da72c);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL5, 0x71486980);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL6, 0x00000e55);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x4800023d);
	} else if (meson_vpu_is_compatible(priv, "amlogic,meson-gxm-vpu") ||
		   meson_vpu_is_compatible(priv, "amlogic,meson-gxl-vpu")) {
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL, 0x4000027b);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL2, 0x800cb300);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL3, 0xa6212844);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL4, 0x0c4d000c);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL5, 0x001fa729);
		regmap_write(priv->hhi, HHI_HDMI_PLL_CNTL6, 0x01a31500);

		/* Reset PLL */
		regmap_update_bits(priv->hhi, HHI_HDMI_PLL_CNTL,
					HDMI_PLL_RESET, HDMI_PLL_RESET);
		regmap_update_bits(priv->hhi, HHI_HDMI_PLL_CNTL,
					HDMI_PLL_RESET, 0);
	}

	/* Poll for lock bit */
	regmap_read_poll_timeout(priv->hhi, HHI_HDMI_PLL_CNTL, val,
				 (val & HDMI_PLL_LOCK), 10, 0);

	/* Disable VCLK2 */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, 0);

	/* Disable vid_pll output clock */
	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV, VID_PLL_EN, 0);
	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV, VID_PLL_PRESET, 0);
	/* Enable vid_pll bypass to HDMI pll */
	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV,
				VID_PLL_BYPASS, VID_PLL_BYPASS);
	/* Enable the vid_pll output clock */
	regmap_update_bits(priv->hhi, HHI_VID_PLL_CLK_DIV,
				VID_PLL_EN, VID_PLL_EN);

	/* Setup the VCLK2 divider value to achieve 27MHz */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
				VCLK2_DIV_MASK, (55 - 1));

	/* select vid_pll for vclk2 */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
				VCLK2_SEL_MASK, (4 << VCLK2_SEL_SHIFT));
	/* enable vclk2 gate */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL, VCLK2_EN, VCLK2_EN);

	/* select vclk_div1 for enci */
	regmap_update_bits(priv->hhi, HHI_VID_CLK_DIV,
				CTS_ENCI_SEL_MASK, (8 << CTS_ENCI_SEL_SHIFT));
	/* select vclk_div1 for vdac */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
				CTS_VDAC_SEL_MASK, (8 << CTS_VDAC_SEL_SHIFT));

	/* release vclk2_div_reset and enable vclk2_div */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_DIV,
				VCLK2_DIV_EN | VCLK2_DIV_RESET, VCLK2_DIV_EN);

	/* enable vclk2_div1 gate */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
				VCLK2_DIV1_EN, VCLK2_DIV1_EN);

	/* reset vclk2 */
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
				VCLK2_SOFT_RESET, VCLK2_SOFT_RESET);
	regmap_update_bits(priv->hhi, HHI_VIID_CLK_CNTL,
				VCLK2_SOFT_RESET, 0);

	/* enable enci_clk */
	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL2,
				CTS_ENCI_EN, CTS_ENCI_EN);
	/* enable vdac_clk */
	regmap_update_bits(priv->hhi, HHI_VID_CLK_CNTL2,
				CTS_VDAC_EN, CTS_VDAC_EN);
}

void meson_vclk_setup(struct meson_drm *priv, unsigned int target,
		      unsigned int freq)
{
	if (target == MESON_VCLK_TARGET_CVBS && freq == MESON_VCLK_CVBS)
		meson_venci_cvbs_clock_config(priv);
}