drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

1 files changed, 272 insertions, 0 deletions

diff --git a/drivers/regulator/max8649.c b/drivers/regulator/max8649.c
new file mode 100644
index 000000000..2d1740524
--- /dev/null
+++ b/drivers/regulator/max8649.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Regulators driver for Maxim max8649
+ *
+ * Copyright (C) 2009-2010 Marvell International Ltd.
+ *      Haojian Zhuang <haojian.zhuang@marvell.com>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/slab.h>
+#include <linux/regulator/max8649.h>
+#include <linux/regmap.h>
+
+#define MAX8649_DCDC_VMIN	750000		/* uV */
+#define MAX8649_DCDC_VMAX	1380000		/* uV */
+#define MAX8649_DCDC_STEP	10000		/* uV */
+#define MAX8649_VOL_MASK	0x3f
+
+/* Registers */
+#define MAX8649_MODE0		0x00
+#define MAX8649_MODE1		0x01
+#define MAX8649_MODE2		0x02
+#define MAX8649_MODE3		0x03
+#define MAX8649_CONTROL		0x04
+#define MAX8649_SYNC		0x05
+#define MAX8649_RAMP		0x06
+#define MAX8649_CHIP_ID1	0x08
+#define MAX8649_CHIP_ID2	0x09
+
+/* Bits */
+#define MAX8649_EN_PD		(1 << 7)
+#define MAX8649_VID0_PD		(1 << 6)
+#define MAX8649_VID1_PD		(1 << 5)
+#define MAX8649_VID_MASK	(3 << 5)
+
+#define MAX8649_FORCE_PWM	(1 << 7)
+#define MAX8649_SYNC_EXTCLK	(1 << 6)
+
+#define MAX8649_EXT_MASK	(3 << 6)
+
+#define MAX8649_RAMP_MASK	(7 << 5)
+#define MAX8649_RAMP_DOWN	(1 << 1)
+
+struct max8649_regulator_info {
+	struct device		*dev;
+	struct regmap		*regmap;
+
+	unsigned	mode:2;	/* bit[1:0] = VID1, VID0 */
+	unsigned	extclk_freq:2;
+	unsigned	extclk:1;
+	unsigned	ramp_timing:3;
+	unsigned	ramp_down:1;
+};
+
+static int max8649_enable_time(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	int voltage, rate, ret;
+	unsigned int val;
+
+	/* get voltage */
+	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
+	if (ret != 0)
+		return ret;
+	val &= MAX8649_VOL_MASK;
+	voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
+
+	/* get rate */
+	ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
+	if (ret != 0)
+		return ret;
+	ret = (val & MAX8649_RAMP_MASK) >> 5;
+	rate = (32 * 1000) >> ret;	/* uV/uS */
+
+	return DIV_ROUND_UP(voltage, rate);
+}
+
+static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+
+	switch (mode) {
+	case REGULATOR_MODE_FAST:
+		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
+				   MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
+		break;
+	case REGULATOR_MODE_NORMAL:
+		regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
+				   MAX8649_FORCE_PWM, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static unsigned int max8649_get_mode(struct regulator_dev *rdev)
+{
+	struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
+	if (ret != 0)
+		return ret;
+	if (val & MAX8649_FORCE_PWM)
+		return REGULATOR_MODE_FAST;
+	return REGULATOR_MODE_NORMAL;
+}
+
+static const struct regulator_ops max8649_dcdc_ops = {
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.list_voltage	= regulator_list_voltage_linear,
+	.map_voltage	= regulator_map_voltage_linear,
+	.enable		= regulator_enable_regmap,
+	.disable	= regulator_disable_regmap,
+	.is_enabled	= regulator_is_enabled_regmap,
+	.enable_time	= max8649_enable_time,
+	.set_mode	= max8649_set_mode,
+	.get_mode	= max8649_get_mode,
+
+};
+
+static struct regulator_desc dcdc_desc = {
+	.name		= "max8649",
+	.ops		= &max8649_dcdc_ops,
+	.type		= REGULATOR_VOLTAGE,
+	.n_voltages	= 1 << 6,
+	.owner		= THIS_MODULE,
+	.vsel_mask	= MAX8649_VOL_MASK,
+	.min_uV		= MAX8649_DCDC_VMIN,
+	.uV_step	= MAX8649_DCDC_STEP,
+	.enable_reg	= MAX8649_CONTROL,
+	.enable_mask	= MAX8649_EN_PD,
+	.enable_is_inverted = true,
+};
+
+static const struct regmap_config max8649_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int max8649_regulator_probe(struct i2c_client *client)
+{
+	struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct max8649_regulator_info *info = NULL;
+	struct regulator_dev *regulator;
+	struct regulator_config config = { };
+	unsigned int val;
+	unsigned char data;
+	int ret;
+
+	info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
+	if (IS_ERR(info->regmap)) {
+		ret = PTR_ERR(info->regmap);
+		dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
+		return ret;
+	}
+
+	info->dev = &client->dev;
+	i2c_set_clientdata(client, info);
+
+	info->mode = pdata->mode;
+	switch (info->mode) {
+	case 0:
+		dcdc_desc.vsel_reg = MAX8649_MODE0;
+		break;
+	case 1:
+		dcdc_desc.vsel_reg = MAX8649_MODE1;
+		break;
+	case 2:
+		dcdc_desc.vsel_reg = MAX8649_MODE2;
+		break;
+	case 3:
+		dcdc_desc.vsel_reg = MAX8649_MODE3;
+		break;
+	default:
+		break;
+	}
+
+	ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
+	if (ret != 0) {
+		dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
+			ret);
+		return ret;
+	}
+	dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
+
+	/* enable VID0 & VID1 */
+	regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
+
+	/* enable/disable external clock synchronization */
+	info->extclk = pdata->extclk;
+	data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
+	regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
+			   MAX8649_SYNC_EXTCLK, data);
+	if (info->extclk) {
+		/* set external clock frequency */
+		info->extclk_freq = pdata->extclk_freq;
+		regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
+				   info->extclk_freq << 6);
+	}
+
+	if (pdata->ramp_timing) {
+		info->ramp_timing = pdata->ramp_timing;
+		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
+				   info->ramp_timing << 5);
+	}
+
+	info->ramp_down = pdata->ramp_down;
+	if (info->ramp_down) {
+		regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
+				   MAX8649_RAMP_DOWN);
+	}
+
+	config.dev = &client->dev;
+	config.init_data = pdata->regulator;
+	config.driver_data = info;
+	config.regmap = info->regmap;
+
+	regulator = devm_regulator_register(&client->dev, &dcdc_desc,
+						  &config);
+	if (IS_ERR(regulator)) {
+		dev_err(info->dev, "failed to register regulator %s\n",
+			dcdc_desc.name);
+		return PTR_ERR(regulator);
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id max8649_id[] = {
+	{ .name = "max8649" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max8649_id);
+
+static struct i2c_driver max8649_driver = {
+	.probe		= max8649_regulator_probe,
+	.driver		= {
+		.name	= "max8649",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+	.id_table	= max8649_id,
+};
+
+static int __init max8649_init(void)
+{
+	return i2c_add_driver(&max8649_driver);
+}
+subsys_initcall(max8649_init);
+
+static void __exit max8649_exit(void)
+{
+	i2c_del_driver(&max8649_driver);
+}
+module_exit(max8649_exit);
+
+/* Module information */
+MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
+MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
+MODULE_LICENSE("GPL");