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, 126 insertions, 0 deletions

diff --git a/drivers/mfd/lp87565.c b/drivers/mfd/lp87565.c
new file mode 100644
index 000000000..b78ae79df
--- /dev/null
+++ b/drivers/mfd/lp87565.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/
+ *
+ * Author: Keerthy <j-keerthy@ti.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/lp87565.h>
+
+static const struct regmap_config lp87565_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = LP87565_REG_MAX,
+};
+
+static const struct mfd_cell lp87565_cells[] = {
+	{ .name = "lp87565-q1-regulator", },
+	{ .name = "lp87565-q1-gpio", },
+};
+
+static const struct of_device_id of_lp87565_match_table[] = {
+	{ .compatible = "ti,lp87565", },
+	{
+		.compatible = "ti,lp87524-q1",
+		.data = (void *)LP87565_DEVICE_TYPE_LP87524_Q1,
+	},
+	{
+		.compatible = "ti,lp87565-q1",
+		.data = (void *)LP87565_DEVICE_TYPE_LP87565_Q1,
+	},
+	{
+		.compatible = "ti,lp87561-q1",
+		.data = (void *)LP87565_DEVICE_TYPE_LP87561_Q1,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_lp87565_match_table);
+
+static int lp87565_probe(struct i2c_client *client)
+{
+	struct lp87565 *lp87565;
+	int ret;
+	unsigned int otpid;
+
+	lp87565 = devm_kzalloc(&client->dev, sizeof(*lp87565), GFP_KERNEL);
+	if (!lp87565)
+		return -ENOMEM;
+
+	lp87565->dev = &client->dev;
+
+	lp87565->regmap = devm_regmap_init_i2c(client, &lp87565_regmap_config);
+	if (IS_ERR(lp87565->regmap)) {
+		ret = PTR_ERR(lp87565->regmap);
+		dev_err(lp87565->dev,
+			"Failed to initialize register map: %d\n", ret);
+		return ret;
+	}
+
+	lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset",
+						      GPIOD_OUT_LOW);
+	if (IS_ERR(lp87565->reset_gpio)) {
+		ret = PTR_ERR(lp87565->reset_gpio);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+	}
+
+	if (lp87565->reset_gpio) {
+		gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
+		/* The minimum assertion time is undocumented, just guess */
+		usleep_range(2000, 4000);
+
+		gpiod_set_value_cansleep(lp87565->reset_gpio, 0);
+		/* Min 1.2 ms before first I2C transaction */
+		usleep_range(1500, 3000);
+	}
+
+	ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid);
+	if (ret) {
+		dev_err(lp87565->dev, "Failed to read OTP ID\n");
+		return ret;
+	}
+
+	lp87565->rev = otpid & LP87565_OTP_REV_OTP_ID;
+	lp87565->dev_type = (uintptr_t)i2c_get_match_data(client);
+
+	i2c_set_clientdata(client, lp87565);
+
+	return devm_mfd_add_devices(lp87565->dev, PLATFORM_DEVID_AUTO,
+				    lp87565_cells, ARRAY_SIZE(lp87565_cells),
+				    NULL, 0, NULL);
+}
+
+static void lp87565_shutdown(struct i2c_client *client)
+{
+	struct lp87565 *lp87565 = i2c_get_clientdata(client);
+
+	gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
+}
+
+static const struct i2c_device_id lp87565_id_table[] = {
+	{ "lp87565-q1" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lp87565_id_table);
+
+static struct i2c_driver lp87565_driver = {
+	.driver	= {
+		.name	= "lp87565",
+		.of_match_table = of_lp87565_match_table,
+	},
+	.probe = lp87565_probe,
+	.shutdown = lp87565_shutdown,
+	.id_table = lp87565_id_table,
+};
+module_i2c_driver(lp87565_driver);
+
+MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
+MODULE_DESCRIPTION("lp87565 chip family Multi-Function Device driver");
+MODULE_LICENSE("GPL v2");