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, 170 insertions, 0 deletions

diff --git a/drivers/mfd/max7360.c b/drivers/mfd/max7360.c
new file mode 100644
index 000000000..52fffed0c
--- /dev/null
+++ b/drivers/mfd/max7360.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Maxim MAX7360 Core Driver
+ *
+ * Copyright 2025 Bootlin
+ *
+ * Authors:
+ *    Kamel Bouhara <kamel.bouhara@bootlin.com>
+ *    Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
+ */
+
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device/devres.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max7360.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+static const struct mfd_cell max7360_cells[] = {
+	{ .name           = "max7360-pinctrl" },
+	{ .name           = "max7360-pwm" },
+	{ .name           = "max7360-keypad" },
+	{ .name           = "max7360-rotary" },
+	{
+		.name           = "max7360-gpo",
+		.of_compatible	= "maxim,max7360-gpo",
+	},
+	{
+		.name           = "max7360-gpio",
+		.of_compatible	= "maxim,max7360-gpio",
+	},
+};
+
+static const struct regmap_range max7360_volatile_ranges[] = {
+	regmap_reg_range(MAX7360_REG_KEYFIFO, MAX7360_REG_KEYFIFO),
+	regmap_reg_range(MAX7360_REG_I2C_TIMEOUT, MAX7360_REG_RTR_CNT),
+};
+
+static const struct regmap_access_table max7360_volatile_table = {
+	.yes_ranges = max7360_volatile_ranges,
+	.n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges),
+};
+
+static const struct regmap_config max7360_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1),
+	.volatile_table = &max7360_volatile_table,
+	.cache_type = REGCACHE_MAPLE,
+};
+
+static int max7360_mask_irqs(struct regmap *regmap)
+{
+	struct device *dev = regmap_get_device(regmap);
+	unsigned int val;
+	int ret;
+
+	/*
+	 * GPIO/PWM interrupts are not masked on reset: as the MAX7360 "INTI"
+	 * interrupt line is shared between GPIOs and rotary encoder, this could
+	 * result in repeated spurious interrupts on the rotary encoder driver
+	 * if the GPIO driver is not loaded. Mask them now to avoid this
+	 * situation.
+	 */
+	for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) {
+		ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i),
+					MAX7360_PORT_CFG_INTERRUPT_MASK,
+					MAX7360_PORT_CFG_INTERRUPT_MASK);
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "Failed to write MAX7360 port configuration\n");
+	}
+
+	/* Read GPIO in register, to ACK any pending IRQ. */
+	ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to read GPIO values\n");
+
+	return 0;
+}
+
+static int max7360_reset(struct regmap *regmap)
+{
+	struct device *dev = regmap_get_device(regmap);
+	int ret;
+
+	ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, MAX7360_GPIO_CFG_GPIO_RST);
+	if (ret) {
+		dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret);
+		return ret;
+	}
+
+	ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG, MAX7360_REG_GPIO_LAST);
+	if (ret) {
+		dev_err(dev, "Failed to drop regmap cache: %x\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0);
+	if (ret) {
+		dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0);
+	if (ret)
+		dev_err(dev, "Failed to reset GPO port count: %x\n", ret);
+
+	return ret;
+}
+
+static int max7360_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+	int ret;
+
+	regmap = devm_regmap_init_i2c(client, &max7360_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialise regmap\n");
+
+	ret = max7360_reset(regmap);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to reset device\n");
+
+	/* Get the device out of shutdown mode. */
+	ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG,
+				MAX7360_GPIO_CFG_GPIO_EN,
+				MAX7360_GPIO_CFG_GPIO_EN);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n");
+
+	ret = max7360_mask_irqs(regmap);
+	if (ret)
+		return dev_err_probe(dev, ret, "Could not mask interrupts\n");
+
+	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				   max7360_cells, ARRAY_SIZE(max7360_cells),
+				   NULL, 0, NULL);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register child devices\n");
+
+	return 0;
+}
+
+static const struct of_device_id max7360_dt_match[] = {
+	{ .compatible = "maxim,max7360" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, max7360_dt_match);
+
+static struct i2c_driver max7360_driver = {
+	.driver = {
+		.name = "max7360",
+		.of_match_table = max7360_dt_match,
+	},
+	.probe = max7360_probe,
+};
+module_i2c_driver(max7360_driver);
+
+MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver");
+MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
+MODULE_LICENSE("GPL");