ASoC: Intel: Skylake: Add D0iX callbacks

The driver needs two DSP callback, one to set D0i0 (active) and D0i3
(low-power) states.

Add these callbacks in dsp ops and implement them for broxton platforms.
Signed-off-by: Jayachandran B <jayachandran.b@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/bxt-sst.c

@@ -43,6 +43,9 @@
 
 #define BXT_ADSP_FW_BIN_HDR_OFFSET 0x2000
 
+/* Delay before scheduling D0i3 entry */
+#define BXT_D0I3_DELAY 5000
+
 static unsigned int bxt_get_errorcode(struct sst_dsp *ctx)
 {
 	 return sst_dsp_shim_read(ctx, BXT_ADSP_ERROR_CODE);
@@ -288,6 +291,141 @@ static int bxt_load_base_firmware(struct sst_dsp *ctx)
 	return ret;
 }
 
+/*
+ * Decide the D0i3 state that can be targeted based on the usecase
+ * ref counts and DSP state
+ *
+ * Decision Matrix:  (X= dont care; state = target state)
+ *
+ * DSP state != SKL_DSP_RUNNING ; state = no d0i3
+ *
+ * DSP state == SKL_DSP_RUNNING , the following matrix applies
+ * non_d0i3 >0; streaming =X; non_streaming =X; state = no d0i3
+ * non_d0i3 =X; streaming =0; non_streaming =0; state = no d0i3
+ * non_d0i3 =0; streaming >0; non_streaming =X; state = streaming d0i3
+ * non_d0i3 =0; streaming =0; non_streaming =X; state = non-streaming d0i3
+ */
+static int bxt_d0i3_target_state(struct sst_dsp *ctx)
+{
+	struct skl_sst *skl = ctx->thread_context;
+	struct skl_d0i3_data *d0i3 = &skl->d0i3;
+
+	if (skl->cores.state[SKL_DSP_CORE0_ID] != SKL_DSP_RUNNING)
+		return SKL_DSP_D0I3_NONE;
+
+	if (d0i3->non_d0i3)
+		return SKL_DSP_D0I3_NONE;
+	else if (d0i3->streaming)
+		return SKL_DSP_D0I3_STREAMING;
+	else if (d0i3->non_streaming)
+		return SKL_DSP_D0I3_NON_STREAMING;
+	else
+		return SKL_DSP_D0I3_NONE;
+}
+
+static void bxt_set_dsp_D0i3(struct work_struct *work)
+{
+	int ret;
+	struct skl_ipc_d0ix_msg msg;
+	struct skl_sst *skl = container_of(work,
+			struct skl_sst, d0i3.work.work);
+	struct sst_dsp *ctx = skl->dsp;
+	struct skl_d0i3_data *d0i3 = &skl->d0i3;
+	int target_state;
+
+	dev_dbg(ctx->dev, "In %s:\n", __func__);
+
+	/* D0i3 entry allowed only if core 0 alone is running */
+	if (skl_dsp_get_enabled_cores(ctx) !=  SKL_DSP_CORE0_MASK) {
+		dev_warn(ctx->dev,
+				"D0i3 allowed when only core0 running:Exit\n");
+		return;
+	}
+
+	target_state = bxt_d0i3_target_state(ctx);
+	if (target_state == SKL_DSP_D0I3_NONE)
+		return;
+
+	msg.instance_id = 0;
+	msg.module_id = 0;
+	msg.wake = 1;
+	msg.streaming = 0;
+	if (target_state == SKL_DSP_D0I3_STREAMING)
+		msg.streaming = 1;
+
+	ret =  skl_ipc_set_d0ix(&skl->ipc, &msg);
+
+	if (ret < 0) {
+		dev_err(ctx->dev, "Failed to set DSP to D0i3 state\n");
+		return;
+	}
+
+	/* Set Vendor specific register D0I3C.I3 to enable D0i3*/
+	if (skl->update_d0i3c)
+		skl->update_d0i3c(skl->dev, true);
+
+	d0i3->state = target_state;
+	skl->cores.state[SKL_DSP_CORE0_ID] = SKL_DSP_RUNNING_D0I3;
+}
+
+static int bxt_schedule_dsp_D0i3(struct sst_dsp *ctx)
+{
+	struct skl_sst *skl = ctx->thread_context;
+	struct skl_d0i3_data *d0i3 = &skl->d0i3;
+
+	/* Schedule D0i3 only if the usecase ref counts are appropriate */
+	if (bxt_d0i3_target_state(ctx) != SKL_DSP_D0I3_NONE) {
+
+		dev_dbg(ctx->dev, "%s: Schedule D0i3\n", __func__);
+
+		schedule_delayed_work(&d0i3->work,
+				msecs_to_jiffies(BXT_D0I3_DELAY));
+	}
+
+	return 0;
+}
+
+static int bxt_set_dsp_D0i0(struct sst_dsp *ctx)
+{
+	int ret;
+	struct skl_ipc_d0ix_msg msg;
+	struct skl_sst *skl = ctx->thread_context;
+
+	dev_dbg(ctx->dev, "In %s:\n", __func__);
+
+	/* First Cancel any pending attempt to put DSP to D0i3 */
+	cancel_delayed_work_sync(&skl->d0i3.work);
+
+	/* If DSP is currently in D0i3, bring it to D0i0 */
+	if (skl->cores.state[SKL_DSP_CORE0_ID] != SKL_DSP_RUNNING_D0I3)
+		return 0;
+
+	dev_dbg(ctx->dev, "Set DSP to D0i0\n");
+
+	msg.instance_id = 0;
+	msg.module_id = 0;
+	msg.streaming = 0;
+	msg.wake = 0;
+
+	if (skl->d0i3.state == SKL_DSP_D0I3_STREAMING)
+		msg.streaming = 1;
+
+	/* Clear Vendor specific register D0I3C.I3 to disable D0i3*/
+	if (skl->update_d0i3c)
+		skl->update_d0i3c(skl->dev, false);
+
+	ret =  skl_ipc_set_d0ix(&skl->ipc, &msg);
+	if (ret < 0) {
+		dev_err(ctx->dev, "Failed to set DSP to D0i0\n");
+		return ret;
+	}
+
+	skl->cores.state[SKL_DSP_CORE0_ID] = SKL_DSP_RUNNING;
+	skl->d0i3.state = SKL_DSP_D0I3_NONE;
+
+	return 0;
+}
+
 static int bxt_set_dsp_D0(struct sst_dsp *ctx, unsigned int core_id)
 {
 	struct skl_sst *skl = ctx->thread_context;
@@ -414,6 +552,8 @@ static int bxt_set_dsp_D3(struct sst_dsp *ctx, unsigned int core_id)
 static struct skl_dsp_fw_ops bxt_fw_ops = {
 	.set_state_D0 = bxt_set_dsp_D0,
 	.set_state_D3 = bxt_set_dsp_D3,
+	.set_state_D0i3 = bxt_schedule_dsp_D0i3,
+	.set_state_D0i0 = bxt_set_dsp_D0i0,
 	.load_fw = bxt_load_base_firmware,
 	.get_fw_errcode = bxt_get_errorcode,
 	.load_library = bxt_load_library,

sound/soc/intel/skylake/skl-sst-dsp.h

@@ -126,11 +126,21 @@ struct sst_dsp_device;
 #define SKL_ADSPCS_CPA_SHIFT		24
 #define SKL_ADSPCS_CPA_MASK(cm)		((cm) << SKL_ADSPCS_CPA_SHIFT)
 
+/* DSP Core state */
 enum skl_dsp_states {
 	SKL_DSP_RUNNING = 1,
+	/* Running in D0i3 state; can be in streaming or non-streaming D0i3 */
+	SKL_DSP_RUNNING_D0I3, /* Running in D0i3 state*/
 	SKL_DSP_RESET,
 };
 
+/* D0i3 substates */
+enum skl_dsp_d0i3_states {
+	SKL_DSP_D0I3_NONE = -1, /* No D0i3 */
+	SKL_DSP_D0I3_NON_STREAMING = 0,
+	SKL_DSP_D0I3_STREAMING = 1,
+};
+
 struct skl_dsp_fw_ops {
 	int (*load_fw)(struct sst_dsp  *ctx);
 	/* FW module parser/loader */
@@ -139,6 +149,8 @@ struct skl_dsp_fw_ops {
 	int (*parse_fw)(struct sst_dsp *ctx);
 	int (*set_state_D0)(struct sst_dsp *ctx, unsigned int core_id);
 	int (*set_state_D3)(struct sst_dsp *ctx, unsigned int core_id);
+	int (*set_state_D0i3)(struct sst_dsp *ctx);
+	int (*set_state_D0i0)(struct sst_dsp *ctx);
 	unsigned int (*get_fw_errcode)(struct sst_dsp *ctx);
 	int (*load_mod)(struct sst_dsp *ctx, u16 mod_id, u8 *mod_name);
 	int (*unload_mod)(struct sst_dsp *ctx, u16 mod_id);

sound/soc/intel/skylake/skl-sst-ipc.h

@@ -53,6 +53,23 @@ struct skl_dsp_cores {
 	int usage_count[SKL_DSP_CORES_MAX];
 };
 
+/**
+ * skl_d0i3_data: skl D0i3 counters data struct
+ *
+ * @streaming: Count of usecases that can attempt streaming D0i3
+ * @non_streaming: Count of usecases that can attempt non-streaming D0i3
+ * @non_d0i3: Count of usecases that cannot attempt D0i3
+ * @state: current state
+ * @work: D0i3 worker thread
+ */
+struct skl_d0i3_data {
+	int streaming;
+	int non_streaming;
+	int non_d0i3;
+	enum skl_dsp_d0i3_states state;
+	struct delayed_work work;
+};
+
 struct skl_sst {
 	struct device *dev;
 	struct sst_dsp *dsp;
@@ -86,6 +103,8 @@ struct skl_sst {
 
 	/* Callback to update D0i3C register */
 	void (*update_d0i3c)(struct device *dev, bool enable);
+
+	struct skl_d0i3_data d0i3;
 };
 
 struct skl_ipc_init_instance_msg {