ASoC: cs35l56: Use PCI SSID to select specific

Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:

The PCI device registers contain a subsystem ID (SSID), that is
separate from the silicon ID. The PCI specification defines it thus:

"They provide a mechanism for board vendors to distiguish their
 boards from one another even thought the boards may have the same
 PCI controller on them."

This allows the driver for the silicon part to apply board-speficic
settings based on this SSID.

The CS35L56 driver uses this to select the correct firmware file for
the board. The actual ID is part of the PCI register set of the
host audio interface so this set of patches includes extracting the
SSID from the Intel audio controller and passing it to the machine
driver and then to ASoC components. Other PCI audio controllers
will have the same SSID registers, so can use the same mechanism to
pass the SSID.

include/sound/soc-acpi.h

@@ -68,6 +68,10 @@ static inline struct snd_soc_acpi_mach *snd_soc_acpi_codec_list(void *arg)
  * @i2s_link_mask: I2S/TDM links enabled on the board
  * @num_dai_drivers: number of elements in @dai_drivers
  * @dai_drivers: pointer to dai_drivers, used e.g. in nocodec mode
+ * @subsystem_vendor: optional PCI SSID vendor value
+ * @subsystem_device: optional PCI SSID device value
+ * @subsystem_id_set: true if a value has been written to
+ *		      subsystem_vendor and subsystem_device.
  */
 struct snd_soc_acpi_mach_params {
 	u32 acpi_ipc_irq_index;
@@ -80,6 +84,9 @@ struct snd_soc_acpi_mach_params {
 	u32 i2s_link_mask;
 	u32 num_dai_drivers;
 	struct snd_soc_dai_driver *dai_drivers;
+	unsigned short subsystem_vendor;
+	unsigned short subsystem_device;
+	bool subsystem_id_set;
 };
 
 /**

include/sound/soc-card.h

@@ -59,6 +59,43 @@ int snd_soc_card_add_dai_link(struct snd_soc_card *card,
 void snd_soc_card_remove_dai_link(struct snd_soc_card *card,
 				  struct snd_soc_dai_link *dai_link);
 
+#ifdef CONFIG_PCI
+static inline void snd_soc_card_set_pci_ssid(struct snd_soc_card *card,
+					     unsigned short vendor,
+					     unsigned short device)
+{
+	card->pci_subsystem_vendor = vendor;
+	card->pci_subsystem_device = device;
+	card->pci_subsystem_set = true;
+}
+
+static inline int snd_soc_card_get_pci_ssid(struct snd_soc_card *card,
+					    unsigned short *vendor,
+					    unsigned short *device)
+{
+	if (!card->pci_subsystem_set)
+		return -ENOENT;
+
+	*vendor = card->pci_subsystem_vendor;
+	*device = card->pci_subsystem_device;
+
+	return 0;
+}
+#else /* !CONFIG_PCI */
+static inline void snd_soc_card_set_pci_ssid(struct snd_soc_card *card,
+					     unsigned short vendor,
+					     unsigned short device)
+{
+}
+
+static inline int snd_soc_card_get_pci_ssid(struct snd_soc_card *card,
+					    unsigned short *vendor,
+					    unsigned short *device)
+{
+	return -ENOENT;
+}
+#endif /* CONFIG_PCI */
+
 /* device driver data */
 static inline void snd_soc_card_set_drvdata(struct snd_soc_card *card,
 					    void *data)

include/sound/soc.h

@@ -929,6 +929,17 @@ struct snd_soc_card {
 #ifdef CONFIG_DMI
 	char dmi_longname[80];
 #endif /* CONFIG_DMI */
+
+#ifdef CONFIG_PCI
+	/*
+	 * PCI does not define 0 as invalid, so pci_subsystem_set indicates
+	 * whether a value has been written to these fields.
+	 */
+	unsigned short pci_subsystem_vendor;
+	unsigned short pci_subsystem_device;
+	bool pci_subsystem_set;
+#endif /* CONFIG_PCI */
+
 	char topology_shortname[32];
 
 	struct device *dev;

include/sound/sof.h

@@ -64,6 +64,14 @@ struct snd_sof_pdata {
 	const char *name;
 	const char *platform;
 
+	/*
+	 * PCI SSID. As PCI does not define 0 as invalid, the subsystem_id_set
+	 * flag indicates that a value has been written to these members.
+	 */
+	unsigned short subsystem_vendor;
+	unsigned short subsystem_device;
+	bool subsystem_id_set;
+
 	struct device *dev;
 
 	/*

sound/soc/codecs/cs35l56.c

@@ -772,9 +772,20 @@ static int cs35l56_component_probe(struct snd_soc_component *component)
 {
 	struct cs35l56_private *cs35l56 = snd_soc_component_get_drvdata(component);
 	struct dentry *debugfs_root = component->debugfs_root;
+	unsigned short vendor, device;
 
 	BUILD_BUG_ON(ARRAY_SIZE(cs35l56_tx_input_texts) != ARRAY_SIZE(cs35l56_tx_input_values));
 
+	if (!cs35l56->dsp.system_name &&
+	    (snd_soc_card_get_pci_ssid(component->card, &vendor, &device) == 0)) {
+		cs35l56->dsp.system_name = devm_kasprintf(cs35l56->base.dev,
+							  GFP_KERNEL,
+							  "%04x%04x",
+							  vendor, device);
+		if (!cs35l56->dsp.system_name)
+			return -ENOMEM;
+	}
+
 	if (!wait_for_completion_timeout(&cs35l56->init_completion,
 					 msecs_to_jiffies(5000))) {
 		dev_err(cs35l56->base.dev, "%s: init_completion timed out\n", __func__);

sound/soc/intel/boards/sof_sdw.c

@@ -1924,6 +1924,12 @@ static int mc_probe(struct platform_device *pdev)
 	for (i = 0; i < ARRAY_SIZE(codec_info_list); i++)
 		codec_info_list[i].amp_num = 0;
 
+	if (mach->mach_params.subsystem_id_set) {
+		snd_soc_card_set_pci_ssid(card,
+					  mach->mach_params.subsystem_vendor,
+					  mach->mach_params.subsystem_device);
+	}
+
 	ret = sof_card_dai_links_create(card);
 	if (ret < 0)
 		return ret;

sound/soc/sof/sof-audio.c

@@ -1031,6 +1031,13 @@ int sof_machine_check(struct snd_sof_dev *sdev)
 		mach = snd_sof_machine_select(sdev);
 		if (mach) {
 			sof_pdata->machine = mach;
+
+			if (sof_pdata->subsystem_id_set) {
+				mach->mach_params.subsystem_vendor = sof_pdata->subsystem_vendor;
+				mach->mach_params.subsystem_device = sof_pdata->subsystem_device;
+				mach->mach_params.subsystem_id_set = true;
+			}
+
 			snd_sof_set_mach_params(mach, sdev);
 			return 0;
 		}

sound/soc/sof/sof-pci-dev.c

@@ -214,6 +214,14 @@ int sof_pci_probe(struct pci_dev *pci, const struct pci_device_id *pci_id)
 		return ret;
 
 	sof_pdata->name = pci_name(pci);
+
+	/* PCI defines a vendor ID of 0xFFFF as invalid. */
+	if (pci->subsystem_vendor != 0xFFFF) {
+		sof_pdata->subsystem_vendor = pci->subsystem_vendor;
+		sof_pdata->subsystem_device = pci->subsystem_device;
+		sof_pdata->subsystem_id_set = true;
+	}
+
 	sof_pdata->desc = desc;
 	sof_pdata->dev = dev;