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, 242 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-ds1390.c b/drivers/rtc/rtc-ds1390.c
new file mode 100644
index 000000000..f7afd6bde
--- /dev/null
+++ b/drivers/rtc/rtc-ds1390.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * rtc-ds1390.c -- driver for the Dallas/Maxim DS1390/93/94 SPI RTC
+ *
+ * Copyright (C) 2008 Mercury IMC Ltd
+ * Written by Mark Jackson <mpfj@mimc.co.uk>
+ *
+ * NOTE: Currently this driver only supports the bare minimum for read
+ * and write the RTC. The extra features provided by the chip family
+ * (alarms, trickle charger, different control registers) are unavailable.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/spi/spi.h>
+#include <linux/bcd.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#define DS1390_REG_100THS		0x00
+#define DS1390_REG_SECONDS		0x01
+#define DS1390_REG_MINUTES		0x02
+#define DS1390_REG_HOURS		0x03
+#define DS1390_REG_DAY			0x04
+#define DS1390_REG_DATE			0x05
+#define DS1390_REG_MONTH_CENT		0x06
+#define DS1390_REG_YEAR			0x07
+
+#define DS1390_REG_ALARM_100THS		0x08
+#define DS1390_REG_ALARM_SECONDS	0x09
+#define DS1390_REG_ALARM_MINUTES	0x0A
+#define DS1390_REG_ALARM_HOURS		0x0B
+#define DS1390_REG_ALARM_DAY_DATE	0x0C
+
+#define DS1390_REG_CONTROL		0x0D
+#define DS1390_REG_STATUS		0x0E
+#define DS1390_REG_TRICKLE		0x0F
+
+#define DS1390_TRICKLE_CHARGER_ENABLE	0xA0
+#define DS1390_TRICKLE_CHARGER_250_OHM	0x01
+#define DS1390_TRICKLE_CHARGER_2K_OHM	0x02
+#define DS1390_TRICKLE_CHARGER_4K_OHM	0x03
+#define DS1390_TRICKLE_CHARGER_NO_DIODE	0x04
+#define DS1390_TRICKLE_CHARGER_DIODE	0x08
+
+struct ds1390 {
+	struct rtc_device *rtc;
+	u8 txrx_buf[9];	/* cmd + 8 registers */
+};
+
+static void ds1390_set_reg(struct device *dev, unsigned char address,
+			   unsigned char data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned char buf[2];
+
+	/* MSB must be '1' to write */
+	buf[0] = address | 0x80;
+	buf[1] = data;
+
+	spi_write(spi, buf, 2);
+}
+
+static int ds1390_get_reg(struct device *dev, unsigned char address,
+				unsigned char *data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct ds1390 *chip = dev_get_drvdata(dev);
+	int status;
+
+	if (!data)
+		return -EINVAL;
+
+	/* Clear MSB to indicate read */
+	chip->txrx_buf[0] = address & 0x7f;
+	/* do the i/o */
+	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 1);
+	if (status != 0)
+		return status;
+
+	*data = chip->txrx_buf[0];
+
+	return 0;
+}
+
+static void ds1390_trickle_of_init(struct spi_device *spi)
+{
+	u32 ohms = 0;
+	u8 value;
+
+	if (of_property_read_u32(spi->dev.of_node, "trickle-resistor-ohms",
+				 &ohms))
+		goto out;
+
+	/* Enable charger */
+	value = DS1390_TRICKLE_CHARGER_ENABLE;
+	if (of_property_read_bool(spi->dev.of_node, "trickle-diode-disable"))
+		value |= DS1390_TRICKLE_CHARGER_NO_DIODE;
+	else
+		value |= DS1390_TRICKLE_CHARGER_DIODE;
+
+	/* Resistor select */
+	switch (ohms) {
+	case 250:
+		value |= DS1390_TRICKLE_CHARGER_250_OHM;
+		break;
+	case 2000:
+		value |= DS1390_TRICKLE_CHARGER_2K_OHM;
+		break;
+	case 4000:
+		value |= DS1390_TRICKLE_CHARGER_4K_OHM;
+		break;
+	default:
+		dev_warn(&spi->dev,
+			 "Unsupported ohm value %02ux in dt\n", ohms);
+		return;
+	}
+
+	ds1390_set_reg(&spi->dev, DS1390_REG_TRICKLE, value);
+
+out:
+	return;
+}
+
+static int ds1390_read_time(struct device *dev, struct rtc_time *dt)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct ds1390 *chip = dev_get_drvdata(dev);
+	int status;
+
+	/* build the message */
+	chip->txrx_buf[0] = DS1390_REG_SECONDS;
+
+	/* do the i/o */
+	status = spi_write_then_read(spi, chip->txrx_buf, 1, chip->txrx_buf, 7);
+	if (status != 0)
+		return status;
+
+	/* The chip sends data in this order:
+	 * Seconds, Minutes, Hours, Day, Date, Month / Century, Year */
+	dt->tm_sec	= bcd2bin(chip->txrx_buf[0]);
+	dt->tm_min	= bcd2bin(chip->txrx_buf[1]);
+	dt->tm_hour	= bcd2bin(chip->txrx_buf[2]);
+	dt->tm_wday	= bcd2bin(chip->txrx_buf[3]);
+	dt->tm_mday	= bcd2bin(chip->txrx_buf[4]);
+	/* mask off century bit */
+	dt->tm_mon	= bcd2bin(chip->txrx_buf[5] & 0x7f) - 1;
+	/* adjust for century bit */
+	dt->tm_year = bcd2bin(chip->txrx_buf[6]) + ((chip->txrx_buf[5] & 0x80) ? 100 : 0);
+
+	return 0;
+}
+
+static int ds1390_set_time(struct device *dev, struct rtc_time *dt)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct ds1390 *chip = dev_get_drvdata(dev);
+
+	/* build the message */
+	chip->txrx_buf[0] = DS1390_REG_SECONDS | 0x80;
+	chip->txrx_buf[1] = bin2bcd(dt->tm_sec);
+	chip->txrx_buf[2] = bin2bcd(dt->tm_min);
+	chip->txrx_buf[3] = bin2bcd(dt->tm_hour);
+	chip->txrx_buf[4] = bin2bcd(dt->tm_wday);
+	chip->txrx_buf[5] = bin2bcd(dt->tm_mday);
+	chip->txrx_buf[6] = bin2bcd(dt->tm_mon + 1) |
+				((dt->tm_year > 99) ? 0x80 : 0x00);
+	chip->txrx_buf[7] = bin2bcd(dt->tm_year % 100);
+
+	/* do the i/o */
+	return spi_write_then_read(spi, chip->txrx_buf, 8, NULL, 0);
+}
+
+static const struct rtc_class_ops ds1390_rtc_ops = {
+	.read_time	= ds1390_read_time,
+	.set_time	= ds1390_set_time,
+};
+
+static int ds1390_probe(struct spi_device *spi)
+{
+	unsigned char tmp;
+	struct ds1390 *chip;
+	int res;
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 8;
+	spi_setup(spi);
+
+	chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, chip);
+
+	res = ds1390_get_reg(&spi->dev, DS1390_REG_SECONDS, &tmp);
+	if (res != 0) {
+		dev_err(&spi->dev, "unable to read device\n");
+		return res;
+	}
+
+	if (spi->dev.of_node)
+		ds1390_trickle_of_init(spi);
+
+	chip->rtc = devm_rtc_device_register(&spi->dev, "ds1390",
+					&ds1390_rtc_ops, THIS_MODULE);
+	if (IS_ERR(chip->rtc)) {
+		dev_err(&spi->dev, "unable to register device\n");
+		res = PTR_ERR(chip->rtc);
+	}
+
+	return res;
+}
+
+static const struct of_device_id ds1390_of_match[] __maybe_unused = {
+	{ .compatible = "dallas,ds1390" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ds1390_of_match);
+
+static const struct spi_device_id ds1390_spi_ids[] = {
+	{ .name = "ds1390" },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ds1390_spi_ids);
+
+static struct spi_driver ds1390_driver = {
+	.driver = {
+		.name	= "rtc-ds1390",
+		.of_match_table = of_match_ptr(ds1390_of_match),
+	},
+	.probe	= ds1390_probe,
+	.id_table = ds1390_spi_ids,
+};
+
+module_spi_driver(ds1390_driver);
+
+MODULE_DESCRIPTION("Dallas/Maxim DS1390/93/94 SPI RTC driver");
+MODULE_AUTHOR("Mark Jackson <mpfj@mimc.co.uk>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:rtc-ds1390");