[PATCH 1/4] ASoC: SOF: sof-pci-dev: don't use the community key on APL Chromebooks

[Pierre-Louis Bossart]

As suggested by MrChromebox, the SOF driver can be used with the SOF
firmware binary signed with the production key. This patch adds an
additional check for the ApolloLake SoC before modifying the default
firmware path.

Note that ApolloLake Chromebooks officially ship with the Skylake
driver, so to use SOF the users have to explicitly opt-in with
'options intel-dspcfg dsp_driver=3'. There is no plan to change the
default selection.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao at linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
---
 sound/soc/sof/sof-pci-dev.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sof/sof-pci-dev.c b/sound/soc/sof/sof-pci-dev.c
index 4d1b7e4ccd3d8..003120721779f 100644
--- a/sound/soc/sof/sof-pci-dev.c
+++ b/sound/soc/sof/sof-pci-dev.c
@@ -12,6 +12,7 @@
 #include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/platform_data/x86/soc.h>
 #include <linux/pm_runtime.h>
 #include <sound/soc-acpi.h>
 #include <sound/soc-acpi-intel-match.h>
@@ -40,6 +41,7 @@ module_param_named(sof_pci_debug, sof_pci_debug, int, 0444);
 MODULE_PARM_DESC(sof_pci_debug, "SOF PCI debug options (0x0 all off)");
 
 static const char *sof_dmi_override_tplg_name;
+static bool sof_dmi_use_community_key;
 
 #define SOF_PCI_DISABLE_PM_RUNTIME BIT(0)
 
@@ -102,15 +104,35 @@ static const struct dmi_system_id sof_tplg_table[] = {
 	{}
 };
 
+/* all Up boards use the community key */
+static int up_use_community_key(const struct dmi_system_id *id)
+{
+	sof_dmi_use_community_key = true;
+	return 1;
+}
+
+/*
+ * For ApolloLake Chromebooks we want to force the use of the Intel production key.
+ * All newer platforms use the community key
+ */
+static int chromebook_use_community_key(const struct dmi_system_id *id)
+{
+	if (!soc_intel_is_apl())
+		sof_dmi_use_community_key = true;
+	return 1;
+}
+
 static const struct dmi_system_id community_key_platforms[] = {
 	{
 		.ident = "Up boards",
+		.callback = up_use_community_key,
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "AAEON"),
 		}
 	},
 	{
 		.ident = "Google Chromebooks",
+		.callback = chromebook_use_community_key,
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Google"),
 		}
@@ -208,7 +230,7 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 			"Module parameter used, changed fw path to %s\n",
 			sof_pdata->fw_filename_prefix);
 
-	} else if (dmi_check_system(community_key_platforms)) {
+	} else if (dmi_check_system(community_key_platforms) && sof_dmi_use_community_key) {
 		sof_pdata->fw_filename_prefix =
 			devm_kasprintf(dev, GFP_KERNEL, "%s/%s",
 				       sof_pdata->desc->default_fw_path[sof_pdata->ipc_type],
-- 
2.30.2