[Intel-gfx] [PATCH 2/2] drm/i915/dmc: Use unversioned firmware paths

[Gustavo Sousa <gustavo.sousa@intel.com>]

As we do not require specific versions anymore, change the convention
for blob filenames to stop using version numbers. This simplifies code
maintenance, since we do not need to keep updating blob paths for new
DMC releases, and also makes DMC loading compatible with systems that do
not have the latest firmware release.

References: https://lore.kernel.org/r/Y3081s7c5ksutpMW@intel.com
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dmc.c | 98 ++++++++++++++++++++----
 1 file changed, 82 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
index 4124b3d37110..b11f0f451dd7 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
@@ -42,51 +42,70 @@
 #define DMC_VERSION_MAJOR(version)	((version) >> 16)
 #define DMC_VERSION_MINOR(version)	((version) & 0xffff)
 
-#define DMC_PATH(platform, major, minor) \
-	"i915/"				 \
-	__stringify(platform) "_dmc_ver" \
-	__stringify(major) "_"		 \
+#define DMC_PATH(platform) \
+	"i915/" __stringify(platform) "_dmc.bin"
+
+/*
+ * New DMC additions should not use this. This is used solely to remain
+ * compatible with systems that have not yet updated DMC blobs to use
+ * unversioned file names.
+ */
+#define DMC_LEGACY_PATH(platform, major, minor) \
+	"i915/"					\
+	__stringify(platform) "_dmc_ver"	\
+	__stringify(major) "_"			\
 	__stringify(minor) ".bin"
 
 #define DISPLAY_VER13_DMC_MAX_FW_SIZE	0x20000
 
 #define DISPLAY_VER12_DMC_MAX_FW_SIZE	ICL_DMC_MAX_FW_SIZE
 
-#define DG2_DMC_PATH			DMC_PATH(dg2, 2, 08)
+#define DG2_DMC_PATH			DMC_PATH(dg2)
+#define DG2_DMC_LEGACY_PATH		DMC_LEGACY_PATH(dg2, 2, 08)
 MODULE_FIRMWARE(DG2_DMC_PATH);
 
-#define ADLP_DMC_PATH			DMC_PATH(adlp, 2, 16)
+#define ADLP_DMC_PATH			DMC_PATH(adlp)
+#define ADLP_DMC_LEGACY_PATH		DMC_LEGACY_PATH(adlp, 2, 16)
 MODULE_FIRMWARE(ADLP_DMC_PATH);
 
-#define ADLS_DMC_PATH			DMC_PATH(adls, 2, 01)
+#define ADLS_DMC_PATH			DMC_PATH(adls)
+#define ADLS_DMC_LEGACY_PATH		DMC_LEGACY_PATH(adls, 2, 01)
 MODULE_FIRMWARE(ADLS_DMC_PATH);
 
-#define DG1_DMC_PATH			DMC_PATH(dg1, 2, 02)
+#define DG1_DMC_PATH			DMC_PATH(dg1)
+#define DG1_DMC_LEGACY_PATH		DMC_LEGACY_PATH(dg1, 2, 02)
 MODULE_FIRMWARE(DG1_DMC_PATH);
 
-#define RKL_DMC_PATH			DMC_PATH(rkl, 2, 03)
+#define RKL_DMC_PATH			DMC_PATH(rkl)
+#define RKL_DMC_LEGACY_PATH		DMC_LEGACY_PATH(rkl, 2, 03)
 MODULE_FIRMWARE(RKL_DMC_PATH);
 
-#define TGL_DMC_PATH			DMC_PATH(tgl, 2, 12)
+#define TGL_DMC_PATH			DMC_PATH(tgl)
+#define TGL_DMC_LEGACY_PATH		DMC_LEGACY_PATH(tgl, 2, 12)
 MODULE_FIRMWARE(TGL_DMC_PATH);
 
-#define ICL_DMC_PATH			DMC_PATH(icl, 1, 09)
+#define ICL_DMC_PATH			DMC_PATH(icl)
+#define ICL_DMC_LEGACY_PATH		DMC_LEGACY_PATH(icl, 1, 09)
 #define ICL_DMC_MAX_FW_SIZE		0x6000
 MODULE_FIRMWARE(ICL_DMC_PATH);
 
-#define GLK_DMC_PATH			DMC_PATH(glk, 1, 04)
+#define GLK_DMC_PATH			DMC_PATH(glk)
+#define GLK_DMC_LEGACY_PATH		DMC_LEGACY_PATH(glk, 1, 04)
 #define GLK_DMC_MAX_FW_SIZE		0x4000
 MODULE_FIRMWARE(GLK_DMC_PATH);
 
-#define KBL_DMC_PATH			DMC_PATH(kbl, 1, 04)
+#define KBL_DMC_PATH			DMC_PATH(kbl)
+#define KBL_DMC_LEGACY_PATH		DMC_LEGACY_PATH(kbl, 1, 04)
 #define KBL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
 MODULE_FIRMWARE(KBL_DMC_PATH);
 
-#define SKL_DMC_PATH			DMC_PATH(skl, 1, 27)
+#define SKL_DMC_PATH			DMC_PATH(skl)
+#define SKL_DMC_LEGACY_PATH		DMC_LEGACY_PATH(skl, 1, 27)
 #define SKL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
 MODULE_FIRMWARE(SKL_DMC_PATH);
 
-#define BXT_DMC_PATH			DMC_PATH(bxt, 1, 07)
+#define BXT_DMC_PATH			DMC_PATH(bxt)
+#define BXT_DMC_LEGACY_PATH		DMC_LEGACY_PATH(bxt, 1, 07)
 #define BXT_DMC_MAX_FW_SIZE		0x3000
 MODULE_FIRMWARE(BXT_DMC_PATH);
 
@@ -821,16 +840,63 @@ static void intel_dmc_runtime_pm_put(struct drm_i915_private *dev_priv)
 	intel_display_power_put(dev_priv, POWER_DOMAIN_INIT, wakeref);
 }
 
+static const char *dmc_legacy_path(struct drm_i915_private *i915)
+{
+	if (IS_DG2(i915)) {
+		return DG2_DMC_LEGACY_PATH;
+	} else if (IS_ALDERLAKE_P(i915)) {
+		return ADLP_DMC_LEGACY_PATH;
+	} else if (IS_ALDERLAKE_S(i915)) {
+		return ADLS_DMC_LEGACY_PATH;
+	} else if (IS_DG1(i915)) {
+		return DG1_DMC_LEGACY_PATH;
+	} else if (IS_ROCKETLAKE(i915)) {
+		return RKL_DMC_LEGACY_PATH;
+	} else if (IS_TIGERLAKE(i915)) {
+		return TGL_DMC_LEGACY_PATH;
+	} else if (DISPLAY_VER(i915) == 11) {
+		return ICL_DMC_LEGACY_PATH;
+	} else if (IS_GEMINILAKE(i915)) {
+		return GLK_DMC_LEGACY_PATH;
+	} else if (IS_KABYLAKE(i915) ||
+		   IS_COFFEELAKE(i915) ||
+		   IS_COMETLAKE(i915)) {
+		return KBL_DMC_LEGACY_PATH;
+	} else if (IS_SKYLAKE(i915)) {
+		return SKL_DMC_LEGACY_PATH;
+	} else if (IS_BROXTON(i915)) {
+		return BXT_DMC_LEGACY_PATH;
+	}
+
+	return NULL;
+}
+
 static void dmc_load_work_fn(struct work_struct *work)
 {
 	struct drm_i915_private *dev_priv;
 	struct intel_dmc *dmc;
 	const struct firmware *fw = NULL;
+	const char *legacy_path;
+	int err;
 
 	dev_priv = container_of(work, typeof(*dev_priv), display.dmc.work);
 	dmc = &dev_priv->display.dmc;
 
-	request_firmware(&fw, dev_priv->display.dmc.fw_path, dev_priv->drm.dev);
+	err = firmware_request_nowarn(&fw, dev_priv->display.dmc.fw_path, dev_priv->drm.dev);
+
+	if (err == -ENOENT && !dev_priv->params.dmc_firmware_path) {
+		legacy_path = dmc_legacy_path(dev_priv);
+		if (legacy_path) {
+			drm_dbg_kms(&dev_priv->drm,
+				    "%s not found, falling back to %s\n",
+				    dmc->fw_path,
+				    legacy_path);
+			err = firmware_request_nowarn(&fw, legacy_path, dev_priv->drm.dev);
+			if (err == 0)
+				dev_priv->display.dmc.fw_path = legacy_path;
+		}
+	}
+
 	parse_dmc_fw(dev_priv, fw);
 
 	if (intel_dmc_has_payload(dev_priv)) {
-- 
2.38.1