video: Add driver for Parade PS8625 dP to LVDS bridge

The initialization table comes from the "Illustration of I2C command
for initialing PS8625" document supplied by Parade.

Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/video/Makefile

@@ -42,3 +42,4 @@ obj-$(CONFIG_VIDEO_TEGRA) += tegra.o
 obj-$(CONFIG_VIDEO_VCXK) += bus_vcxk.o
 obj-$(CONFIG_FORMIKE) += formike.o
 obj-$(CONFIG_AM335X_LCD) += am335x-fb.o
+obj-$(CONFIG_VIDEO_PARADE) += parade.o

drivers/video/parade.c

@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * This file is a driver for Parade dP<->LVDS bridges. The original submission
+ * is for the ps8625 chip.
+ */
+#include <config.h>
+#include <common.h>
+#include <i2c.h>
+#include <fdtdec.h>
+
+/*
+ * Initialization of the chip is a process of writing certaing values into
+ * certain registers over i2c bus. The chip in fact responds to a range of
+ * addresses on the i2c bus, so for each written value three parameters are
+ * required: i2c address, register address and the actual value.
+ *
+ * The base address is derived from the device tree, only address offset is
+ * stored in the table below.
+ */
+/**
+ * struct reg_data() - data for a parade register write
+ *
+ * @addr_off        offset from the i2c base address for parade
+ * @reg_addr        register address to write
+ * @value           value to be written
+ */
+struct reg_data {
+	uint8_t addr_off;
+	uint8_t reg;
+	uint8_t value;
+} _packed;
+
+#define END_OF_TABLE 0xff /* Ficticious offset */
+
+static const struct reg_data parade_values[] = {
+	{0x02, 0xa1, 0x01},  /* HPD low */
+	 /*
+	  * SW setting
+	  * [1:0] SW output 1.2V voltage is lower to 96%
+	  */
+	{0x04, 0x14, 0x01},
+	 /*
+	  * RCO SS setting
+	  * [5:4] = b01 0.5%, b10 1%, b11 1.5%
+	  */
+	{0x04, 0xe3, 0x20},
+	{0x04, 0xe2, 0x80}, /* [7] RCO SS enable */
+	 /*
+	  *  RPHY Setting
+	  * [3:2] CDR tune wait cycle before
+	  * measure for fine tune b00: 1us,
+	  * 01: 0.5us, 10:2us, 11:4us.
+	  */
+	{0x04, 0x8a, 0x0c},
+	{0x04, 0x89, 0x08}, /* [3] RFD always on */
+	 /*
+	  * CTN lock in/out:
+	  * 20000ppm/80000ppm. Lock out 2
+	  * times.
+	  */
+	{0x04, 0x71, 0x2d},
+	 /*
+	  * 2.7G CDR settings
+	  * NOF=40LSB for HBR CDR setting
+	  */
+	{0x04, 0x7d, 0x07},
+	{0x04, 0x7b, 0x00},  /* [1:0] Fmin=+4bands */
+	{0x04, 0x7a, 0xfd},  /* [7:5] DCO_FTRNG=+-40% */
+	 /*
+	  * 1.62G CDR settings
+	  * [5:2]NOF=64LSB [1:0]DCO scale is 2/5
+	  */
+	{0x04, 0xc0, 0x12},
+	{0x04, 0xc1, 0x92},  /* Gitune=-37% */
+	{0x04, 0xc2, 0x1c},  /* Fbstep=100% */
+	{0x04, 0x32, 0x80},  /* [7] LOS signal disable */
+	 /*
+	  * RPIO Setting
+	  * [7:4] LVDS driver bias current :
+	  * 75% (250mV swing)
+	  */
+	{0x04, 0x00, 0xb0},
+	 /*
+	  * [7:6] Right-bar GPIO output strength is 8mA
+	  */
+	{0x04, 0x15, 0x40},
+	 /* EQ Training State Machine Setting */
+	{0x04, 0x54, 0x10},  /* RCO calibration start */
+	 /* [4:0] MAX_LANE_COUNT set to one lane */
+	{0x01, 0x02, 0x81},
+	 /* [4:0] LANE_COUNT_SET set to one lane */
+	{0x01, 0x21, 0x81},
+	{0x00, 0x52, 0x20},
+	{0x00, 0xf1, 0x03},  /* HPD CP toggle enable */
+	{0x00, 0x62, 0x41},
+	 /* Counter number, add 1ms counter delay */
+	{0x00, 0xf6, 0x01},
+	 /*
+	  * [6]PWM function control by
+	  * DPCD0040f[7], default is PWM
+	  * block always works.
+	  */
+	{0x00, 0x77, 0x06},
+	 /*
+	  * 04h Adjust VTotal tolerance to
+	  * fix the 30Hz no display issue
+	  */
+	{0x00, 0x4c, 0x04},
+	 /* DPCD00400='h00, Parade OUI = 'h001cf8 */
+	{0x01, 0xc0, 0x00},
+	{0x01, 0xc1, 0x1c},  /* DPCD00401='h1c */
+	{0x01, 0xc2, 0xf8},  /* DPCD00402='hf8 */
+	 /*
+	  * DPCD403~408 = ASCII code
+	  * D2SLV5='h4432534c5635
+	  */
+	{0x01, 0xc3, 0x44},
+	{0x01, 0xc4, 0x32},  /* DPCD404 */
+	{0x01, 0xc5, 0x53},  /* DPCD405 */
+	{0x01, 0xc6, 0x4c},  /* DPCD406 */
+	{0x01, 0xc7, 0x56},  /* DPCD407 */
+	{0x01, 0xc8, 0x35},  /* DPCD408 */
+	 /*
+	  * DPCD40A, Initial Code major  revision
+	  * '01'
+	  */
+	{0x01, 0xca, 0x01},
+	 /* DPCD40B, Initial Code minor revision '05' */
+	{0x01, 0xcb, 0x05},
+	 /* DPCD720, Select internal PWM */
+	{0x01, 0xa5, 0xa0},
+	 /*
+	  * FFh for 100% PWM of brightness, 0h for 0%
+	  * brightness
+	  */
+	{0x01, 0xa7, 0xff},
+	 /*
+	  * Set LVDS output as 6bit-VESA mapping,
+	  * single LVDS channel
+	  */
+	{0x01, 0xcc, 0x13},
+	 /* Enable SSC set by register */
+	{0x02, 0xb1, 0x20},
+	 /*
+	  * Set SSC enabled and +/-1% central
+	  * spreading
+	  */
+	{0x04, 0x10, 0x16},
+	 /* MPU Clock source: LC => RCO */
+	{0x04, 0x59, 0x60},
+	{0x04, 0x54, 0x14},  /* LC -> RCO */
+	{0x02, 0xa1, 0x91},  /* HPD high */
+	{END_OF_TABLE}
+};
+
+/**
+ * Write values table into the Parade eDP bridge
+ *
+ * @return      0 on success, non-0 on failure
+ */
+
+static int parade_write_regs(int base_addr, const struct reg_data *table)
+{
+	int ret = 0;
+
+	while (!ret && (table->addr_off != END_OF_TABLE)) {
+		ret = i2c_write(base_addr + table->addr_off,
+				table->reg, 1,
+				(uint8_t *)&table->value,
+				sizeof(table->value));
+		table++;
+	}
+	return ret;
+}
+
+int parade_init(const void *blob)
+{
+	int bus, old_bus;
+	int parent;
+	int node;
+	int addr;
+	int ret;
+
+	node = fdtdec_next_compatible(blob, 0, COMPAT_PARADE_PS8625);
+	if (node < 0)
+		return 0;
+
+	parent = fdt_parent_offset(blob, node);
+	if (parent < 0) {
+		debug("%s: Could not find parent i2c node\n", __func__);
+		return -1;
+	}
+	addr = fdtdec_get_int(blob, node, "reg", -1);
+	if (addr < 0) {
+		debug("%s: Could not find i2c address\n", __func__);
+		return -1;
+	}
+
+	bus = i2c_get_bus_num_fdt(parent);
+	old_bus = i2c_get_bus_num();
+
+	debug("%s: Using i2c bus %d\n", __func__, bus);
+
+	/*
+	 * TODO(sjg@chromium.org): Hmmm we seem to need some sort of delay
+	 * here.
+	 */
+	mdelay(40);
+	i2c_set_bus_num(bus);
+	ret = parade_write_regs(addr, parade_values);
+
+	i2c_set_bus_num(old_bus);
+
+	return ret;
+}

include/fdtdec.h

@@ -95,6 +95,7 @@ enum fdt_compat_id {
 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
+	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
 
 	COMPAT_COUNT,
 };

lib/fdtdec.c

@@ -71,6 +71,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
 	COMPAT(TI_TPS65090, "ti,tps65090"),
 	COMPAT(COMPAT_NXP_PTN3460, "nxp,ptn3460"),
 	COMPAT(SAMSUNG_EXYNOS_SYSMMU, "samsung,sysmmu-v3.3"),
+	COMPAT(PARADE_PS8625, "parade,ps8625"),
 };
 
 const char *fdtdec_get_compatible(enum fdt_compat_id id)