ASoC: SOF: acpi: enable PM for ACPI platforms

This patch adds the platform-specific PM callbacks for
the BYT/CHT ACPI platforms. Since the Minnowboards
do not support PM, the SOF device is prevented from
entering runtime suspend by incrementing the ref count
after the topology is loaded.

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>

Author: ranj063

sound/soc/sof/core.c

@@ -16,6 +16,9 @@
 #include "sof-priv.h"
 #include "ops.h"
 
+bool no_PM_support;
+EXPORT_SYMBOL(no_PM_support);
+
 /* see SOF_DBG_ flags */
 int sof_core_debug;
 module_param_named(sof_debug, sof_core_debug, int, 0444);

sound/soc/sof/intel/byt.c

@@ -483,6 +483,34 @@ static int tangier_pci_probe(struct snd_sof_dev *sdev)
 	return ret;
 }
 
+static int byt_suspend(struct snd_sof_dev *sdev)
+{
+	/* put DSP into reset, set reset vector and stall */
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_CSR,
+				  SHIM_BYT_CSR_RST | SHIM_BYT_CSR_VECTOR_SEL |
+				  SHIM_BYT_CSR_STALL,
+				  SHIM_BYT_CSR_RST | SHIM_BYT_CSR_VECTOR_SEL |
+				  SHIM_BYT_CSR_STALL);
+}
+
+static int byt_resume(struct snd_sof_dev *sdev)
+{
+	/* enable Interrupt from both sides */
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRX, 0x3, 0x0);
+	snd_sof_dsp_update_bits64(sdev, BYT_DSP_BAR, SHIM_IMRD, 0x3, 0x0);
+}
+
+/* Dummy runtime PM ops. Without these top-level PM callbacks will break */
+static int byt_runtime_suspend(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
+static int byt_runtime_resume(struct snd_sof_dev *sdev)
+{
+	return 0;
+}
+
 const struct snd_sof_dsp_ops sof_tng_ops = {
 	/* device init */
 	.probe		= tangier_pci_probe,
@@ -529,6 +557,12 @@ const struct snd_sof_dsp_ops sof_tng_ops = {
 	/*Firmware loading */
 	.load_firmware	= snd_sof_load_firmware_memcpy,
 
+	/* PM */
+	.suspend = byt_suspend,
+	.resume = byt_resume,
+	.runtime_suspend = byt_runtime_suspend,
+	.runtime_resume = byt_runtime_resume,
+
 	/* DAI drivers */
 	.drv = byt_dai,
 	.num_drv = 3, /* we have only 3 SSPs on byt*/
@@ -690,6 +724,12 @@ const struct snd_sof_dsp_ops sof_byt_ops = {
 	/*Firmware loading */
 	.load_firmware	= snd_sof_load_firmware_memcpy,
 
+	/* PM */
+	.suspend = byt_suspend,
+	.resume = byt_resume,
+	.runtime_suspend = byt_runtime_suspend,
+	.runtime_resume = byt_runtime_resume,
+
 	/* DAI drivers */
 	.drv = byt_dai,
 	.num_drv = 3, /* we have only 3 SSPs on byt*/
@@ -749,6 +789,12 @@ const struct snd_sof_dsp_ops sof_cht_ops = {
 	/*Firmware loading */
 	.load_firmware	= snd_sof_load_firmware_memcpy,
 
+	/* PM */
+	.suspend = byt_suspend,
+	.resume = byt_resume,
+	.runtime_suspend = byt_runtime_suspend,
+	.runtime_resume = byt_runtime_resume,
+
 	/* DAI drivers */
 	.drv = byt_dai,
 	/* all 6 SSPs may be available for cherrytrail */

sound/soc/sof/pcm.c

@@ -733,11 +733,11 @@ static int sof_pcm_probe(struct snd_soc_component *component)
 	}
 
 	/*
-	 * Some platforms in SOF, ex: BYT, may not have their platform PM
-	 * callbacks set. Increment the usage count so as to
-	 * prevent the device from entering runtime suspend.
+	 * Some boards such as the Minnowboard do not support PM.
+	 * Increment the usage count so as to prevent the device
+	 * from entering runtime suspend.
 	 */
-	if (!sof_ops(sdev)->runtime_suspend || !sof_ops(sdev)->runtime_resume)
+	if (no_PM_support)
 		pm_runtime_get_noresume(sdev->dev);
 
 	return ret;

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

@@ -12,6 +12,7 @@
 #include <linux/firmware.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/dmi.h>
 #include <sound/soc-acpi.h>
 #include <sound/soc-acpi-intel-match.h>
 #include <sound/sof.h>
@@ -117,6 +118,33 @@ static const struct sof_dev_desc sof_acpi_cherrytrail_desc = {
 	.arch_ops = &sof_xtensa_arch_ops
 };
 
+static int byt_rt5651_quirk_cb(const struct dmi_system_id *id)
+{
+	/* S3 is not supported for Minnowboards */
+	no_PM_support = true;
+	return 1;
+}
+
+static const struct dmi_system_id byt_rt5651_quirk_table[] = {
+	{
+		/* Minnowboard Max B3 */
+		.callback = byt_rt5651_quirk_cb,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Circuitco"),
+			DMI_MATCH(DMI_PRODUCT_NAME,
+				  "Minnowboard Max B3 PLATFORM"),
+		},
+	},
+	{
+		/* Minnowboard Turbot */
+		.callback = byt_rt5651_quirk_cb,
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ADI"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Minnowboard Turbot"),
+		},
+	},
+};
+
 #endif
 
 static const struct dev_pm_ops sof_acpi_pm = {
@@ -133,7 +161,15 @@ static void sof_acpi_probe_complete(struct device *dev)
 	/* allow runtime_pm */
 	pm_runtime_set_autosuspend_delay(dev, SND_SOF_SUSPEND_DELAY_MS);
 	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
+	pm_runtime_mark_last_busy(dev);
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_BAYTRAIL)
+	/* check for Minnowboards and mark no PM support */
+	dmi_check_system(byt_rt5651_quirk_table);
+#endif
+
 }
 
 static int sof_acpi_probe(struct platform_device *pdev)

sound/soc/sof/sof-priv.h

@@ -39,6 +39,9 @@
 /* global debug state set by SOF_DBG_ flags */
 extern int sof_core_debug;
 
+/* global flag to indicate if PM is supported */
+extern bool no_PM_support;
+
 /* max BARs mmaped devices can use */
 #define SND_SOF_BARS	8