Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 189 insertions, 0 deletions

diff --git a/drivers/gpu/drm/bridge/cros-ec-anx7688.c b/drivers/gpu/drm/bridge/cros-ec-anx7688.c
new file mode 100644
index 0000000000..c8abd9920f
--- /dev/null
+++ b/drivers/gpu/drm/bridge/cros-ec-anx7688.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CrOS EC ANX7688 HDMI->DP bridge driver
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_print.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+/* Register addresses */
+#define ANX7688_VENDOR_ID_REG		0x00
+#define ANX7688_DEVICE_ID_REG		0x02
+
+#define ANX7688_FW_VERSION_REG		0x80
+
+#define ANX7688_DP_BANDWIDTH_REG	0x85
+#define ANX7688_DP_LANE_COUNT_REG	0x86
+
+#define ANX7688_VENDOR_ID		0x1f29
+#define ANX7688_DEVICE_ID		0x7688
+
+/* First supported firmware version (0.85) */
+#define ANX7688_MINIMUM_FW_VERSION	0x0085
+
+static const struct regmap_config cros_ec_anx7688_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+struct cros_ec_anx7688 {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+	bool filter;
+};
+
+static inline struct cros_ec_anx7688 *
+bridge_to_cros_ec_anx7688(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct cros_ec_anx7688, bridge);
+}
+
+static bool cros_ec_anx7688_bridge_mode_fixup(struct drm_bridge *bridge,
+					      const struct drm_display_mode *mode,
+					      struct drm_display_mode *adjusted_mode)
+{
+	struct cros_ec_anx7688 *anx = bridge_to_cros_ec_anx7688(bridge);
+	int totalbw, requiredbw;
+	u8 dpbw, lanecount;
+	u8 regs[2];
+	int ret;
+
+	if (!anx->filter)
+		return true;
+
+	/* Read both regs 0x85 (bandwidth) and 0x86 (lane count). */
+	ret = regmap_bulk_read(anx->regmap, ANX7688_DP_BANDWIDTH_REG, regs, 2);
+	if (ret < 0) {
+		DRM_ERROR("Failed to read bandwidth/lane count\n");
+		return false;
+	}
+	dpbw = regs[0];
+	lanecount = regs[1];
+
+	/* Maximum 0x19 bandwidth (6.75 Gbps Turbo mode), 2 lanes */
+	if (dpbw > 0x19 || lanecount > 2) {
+		DRM_ERROR("Invalid bandwidth/lane count (%02x/%d)\n", dpbw,
+			  lanecount);
+		return false;
+	}
+
+	/* Compute available bandwidth (kHz) */
+	totalbw = dpbw * lanecount * 270000 * 8 / 10;
+
+	/* Required bandwidth (8 bpc, kHz) */
+	requiredbw = mode->clock * 8 * 3;
+
+	DRM_DEBUG_KMS("DP bandwidth: %d kHz (%02x/%d); mode requires %d Khz\n",
+		      totalbw, dpbw, lanecount, requiredbw);
+
+	if (totalbw == 0) {
+		DRM_ERROR("Bandwidth/lane count are 0, not rejecting modes\n");
+		return true;
+	}
+
+	return totalbw >= requiredbw;
+}
+
+static const struct drm_bridge_funcs cros_ec_anx7688_bridge_funcs = {
+	.mode_fixup = cros_ec_anx7688_bridge_mode_fixup,
+};
+
+static int cros_ec_anx7688_bridge_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct cros_ec_anx7688 *anx7688;
+	u16 vendor, device, fw_version;
+	u8 buffer[4];
+	int ret;
+
+	anx7688 = devm_kzalloc(dev, sizeof(*anx7688), GFP_KERNEL);
+	if (!anx7688)
+		return -ENOMEM;
+
+	anx7688->client = client;
+	i2c_set_clientdata(client, anx7688);
+
+	anx7688->regmap = devm_regmap_init_i2c(client, &cros_ec_anx7688_regmap_config);
+	if (IS_ERR(anx7688->regmap)) {
+		ret = PTR_ERR(anx7688->regmap);
+		dev_err(dev, "regmap i2c init failed: %d\n", ret);
+		return ret;
+	}
+
+	/* Read both vendor and device id (4 bytes). */
+	ret = regmap_bulk_read(anx7688->regmap, ANX7688_VENDOR_ID_REG,
+			       buffer, 4);
+	if (ret) {
+		dev_err(dev, "Failed to read chip vendor/device id\n");
+		return ret;
+	}
+
+	vendor = (u16)buffer[1] << 8 | buffer[0];
+	device = (u16)buffer[3] << 8 | buffer[2];
+	if (vendor != ANX7688_VENDOR_ID || device != ANX7688_DEVICE_ID) {
+		dev_err(dev, "Invalid vendor/device id %04x/%04x\n",
+			vendor, device);
+		return -ENODEV;
+	}
+
+	ret = regmap_bulk_read(anx7688->regmap, ANX7688_FW_VERSION_REG,
+			       buffer, 2);
+	if (ret) {
+		dev_err(dev, "Failed to read firmware version\n");
+		return ret;
+	}
+
+	fw_version = (u16)buffer[0] << 8 | buffer[1];
+	dev_info(dev, "ANX7688 firmware version 0x%04x\n", fw_version);
+
+	anx7688->bridge.of_node = dev->of_node;
+
+	/* FW version >= 0.85 supports bandwidth/lane count registers */
+	if (fw_version >= ANX7688_MINIMUM_FW_VERSION)
+		anx7688->filter = true;
+	else
+		/* Warn, but not fail, for backwards compatibility */
+		DRM_WARN("Old ANX7688 FW version (0x%04x), not filtering\n",
+			 fw_version);
+
+	anx7688->bridge.funcs = &cros_ec_anx7688_bridge_funcs;
+	drm_bridge_add(&anx7688->bridge);
+
+	return 0;
+}
+
+static void cros_ec_anx7688_bridge_remove(struct i2c_client *client)
+{
+	struct cros_ec_anx7688 *anx7688 = i2c_get_clientdata(client);
+
+	drm_bridge_remove(&anx7688->bridge);
+}
+
+static const struct of_device_id cros_ec_anx7688_bridge_match_table[] = {
+	{ .compatible = "google,cros-ec-anx7688" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, cros_ec_anx7688_bridge_match_table);
+
+static struct i2c_driver cros_ec_anx7688_bridge_driver = {
+	.probe = cros_ec_anx7688_bridge_probe,
+	.remove = cros_ec_anx7688_bridge_remove,
+	.driver = {
+		.name = "cros-ec-anx7688-bridge",
+		.of_match_table = cros_ec_anx7688_bridge_match_table,
+	},
+};
+
+module_i2c_driver(cros_ec_anx7688_bridge_driver);
+
+MODULE_DESCRIPTION("ChromeOS EC ANX7688 HDMI->DP bridge driver");
+MODULE_AUTHOR("Nicolas Boichat <drinkcat@chromium.org>");
+MODULE_AUTHOR("Enric Balletbo i Serra <enric.balletbo@collabora.com>");
+MODULE_LICENSE("GPL");