ASoC: SOF: Intel: hda-dsp: Add helper for setting DSP D0ix substate

Adding helper to implement setting dsp to d0i3 or d0i0 status, this will
be needed for driver D0ix support.

Signed-off-by: Keyon Jie <[e-mail]>
Signed-off-by: Pierre-Louis Bossart <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/sof/intel/hda-dsp.c

···
 			HDA_DSP_REG_HIPCCTL_BUSY | HDA_DSP_REG_HIPCCTL_DONE, 0);
 }
 
+static int hda_dsp_wait_d0i3c_done(struct snd_sof_dev *sdev, int retry)
+{
+	struct hdac_bus *bus = sof_to_bus(sdev);
+
+	while (snd_hdac_chip_readb(bus, VS_D0I3C) & SOF_HDA_VS_D0I3C_CIP) {
+		if (!retry--)
+			return -ETIMEDOUT;
+		usleep_range(10, 15);
+	}
+
+	return 0;
+}
+
+int hda_dsp_set_power_state(struct snd_sof_dev *sdev,
+			    enum sof_d0_substate d0_substate)
+{
+	struct hdac_bus *bus = sof_to_bus(sdev);
+	int retry = 50;
+	int ret;
+	u8 value;
+
+	/* Write to D0I3C after Command-In-Progress bit is cleared */
+	ret = hda_dsp_wait_d0i3c_done(sdev, retry);
+	if (ret < 0) {
+		dev_err(bus->dev, "CIP timeout before update D0I3C!\n");
+		return ret;
+	}
+
+	/* Update D0I3C register */
+	value = d0_substate == SOF_DSP_D0I3 ? SOF_HDA_VS_D0I3C_I3 : 0;
+	snd_hdac_chip_updateb(bus, VS_D0I3C, SOF_HDA_VS_D0I3C_I3, value);
+
+	/* Wait for cmd in progress to be cleared before exiting the function */
+	retry = 50;
+	ret = hda_dsp_wait_d0i3c_done(sdev, retry);
+	if (ret < 0) {
+		dev_err(bus->dev, "CIP timeout after D0I3C updated!\n");
+		return ret;
+	}
+
+	dev_vdbg(bus->dev, "D0I3C updated, register = 0x%x\n",
+		 snd_hdac_chip_readb(bus, VS_D0I3C));
+
+	return 0;
+}
+
 static int hda_suspend(struct snd_sof_dev *sdev, bool runtime_suspend)
 {
 	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;

sound/soc/sof/intel/hda.h

···
 #define SOF_HDA_PPCTL_PIE		BIT(31)
 #define SOF_HDA_PPCTL_GPROCEN		BIT(30)
 
+/*Vendor Specific Registers*/
+#define SOF_HDA_VS_D0I3C		0x104A
+
+/* D0I3C Register fields */
+#define SOF_HDA_VS_D0I3C_CIP		BIT(0) /* Command-In-Progress */
+#define SOF_HDA_VS_D0I3C_I3		BIT(2) /* D0i3 enable bit */
+
 /* DPIB entry size: 8 Bytes = 2 DWords */
 #define SOF_HDA_DPIB_ENTRY_SIZE	0x8
 
···
 				  unsigned int core_mask);
 void hda_dsp_ipc_int_enable(struct snd_sof_dev *sdev);
 void hda_dsp_ipc_int_disable(struct snd_sof_dev *sdev);
+
+int hda_dsp_set_power_state(struct snd_sof_dev *sdev,
+			    enum sof_d0_substate d0_substate);
 
 int hda_dsp_suspend(struct snd_sof_dev *sdev);
 int hda_dsp_resume(struct snd_sof_dev *sdev);