ASoC: Intel: avs: Inter process communication

Implement the IPC between Intel audio firmware and kernel driver. The
IPC allows transmission of requests, handling of responses as well as
unsolicited (i.e. firmware-generated) notifications.

A subscription mechanism is added to enable different parts of the
driver to register for specific notifications.

The part of the DSP boot process that involves sending ROM message
requires an extra step - must be followed by unstall operation of
MAIN_CORE. All other types of messages do not require such specific
handling, so separate set of functions is provided for sending these.

Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20220311153544.136854-5-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 100 insertions, 0 deletions

diff --git a/sound/soc/intel/avs/avs.h b/sound/soc/intel/avs/avs.h
index 2aefd1969644..330898d8ce2d 100644
--- a/sound/soc/intel/avs/avs.h
+++ b/sound/soc/intel/avs/avs.h
@@ -11,13 +11,27 @@
 
 #include <linux/device.h>
 #include <sound/hda_codec.h>
+#include "messages.h"
 
 struct avs_dev;
 
+/*
+ * struct avs_dsp_ops - Platform-specific DSP operations
+ *
+ * @power: Power on or off DSP cores
+ * @reset: Enter or exit reset state on DSP cores
+ * @stall: Stall or run DSP cores
+ * @irq_handler: Top half of IPC servicing
+ * @irq_thread: Bottom half of IPC servicing
+ * @int_control: Enable or disable IPC interrupts
+ */
 struct avs_dsp_ops {
 	int (* const power)(struct avs_dev *, u32, bool);
 	int (* const reset)(struct avs_dev *, u32, bool);
 	int (* const stall)(struct avs_dev *, u32, bool);
+	irqreturn_t (* const irq_handler)(int, void *);
+	irqreturn_t (* const irq_thread)(int, void *);
+	void (* const int_control)(struct avs_dev *, bool);
 };
 
 #define avs_dsp_op(adev, op, ...) \
@@ -34,6 +48,9 @@ struct avs_spec {
 
 	const u32 core_init_mask;	/* used during DSP boot */
 	const u64 attributes;		/* bitmask of AVS_PLATATTR_* */
+	const u32 sram_base_offset;
+	const u32 sram_window_size;
+	const u32 rom_status;
 };
 
 /*
@@ -49,6 +66,9 @@ struct avs_dev {
 
 	void __iomem *dsp_ba;
 	const struct avs_spec *spec;
+	struct avs_ipc *ipc;
+
+	struct completion fw_ready;
 };
 
 /* from hda_bus to avs_dev */
@@ -68,4 +88,84 @@ int avs_dsp_core_stall(struct avs_dev *adev, u32 core_mask, bool stall);
 int avs_dsp_core_enable(struct avs_dev *adev, u32 core_mask);
 int avs_dsp_core_disable(struct avs_dev *adev, u32 core_mask);
 
+/* Inter Process Communication */
+
+struct avs_ipc_msg {
+	union {
+		u64 header;
+		union avs_global_msg glb;
+		union avs_reply_msg rsp;
+	};
+	void *data;
+	size_t size;
+};
+
+/*
+ * struct avs_ipc - DSP IPC context
+ *
+ * @dev: PCI device
+ * @rx: Reply message cache
+ * @default_timeout_ms: default message timeout in MS
+ * @ready: whether firmware is ready and communication is open
+ * @rx_completed: whether RX for previously sent TX has been received
+ * @rx_lock: for serializing manipulation of rx_* fields
+ * @msg_lock: for synchronizing request handling
+ * @done_completion: DONE-part of IPC i.e. ROM and ACKs from FW
+ * @busy_completion: BUSY-part of IPC i.e. receiving responses from FW
+ */
+struct avs_ipc {
+	struct device *dev;
+
+	struct avs_ipc_msg rx;
+	u32 default_timeout_ms;
+	bool ready;
+
+	bool rx_completed;
+	spinlock_t rx_lock;
+	struct mutex msg_mutex;
+	struct completion done_completion;
+	struct completion busy_completion;
+};
+
+#define AVS_EIPC	EREMOTEIO
+/*
+ * IPC handlers may return positive value (firmware error code) what denotes
+ * successful HOST <-> DSP communication yet failure to process specific request.
+ *
+ * Below macro converts returned value to linux kernel error code.
+ * All IPC callers MUST use it as soon as firmware error code is consumed.
+ */
+#define AVS_IPC_RET(ret) \
+	(((ret) <= 0) ? (ret) : -AVS_EIPC)
+
+static inline void avs_ipc_err(struct avs_dev *adev, struct avs_ipc_msg *tx,
+			       const char *name, int error)
+{
+	/*
+	 * If IPC channel is blocked e.g.: due to ongoing recovery,
+	 * -EPERM error code is expected and thus it's not an actual error.
+	 */
+	if (error == -EPERM)
+		dev_dbg(adev->dev, "%s 0x%08x 0x%08x failed: %d\n", name,
+			tx->glb.primary, tx->glb.ext.val, error);
+	else
+		dev_err(adev->dev, "%s 0x%08x 0x%08x failed: %d\n", name,
+			tx->glb.primary, tx->glb.ext.val, error);
+}
+
+irqreturn_t avs_dsp_irq_handler(int irq, void *dev_id);
+irqreturn_t avs_dsp_irq_thread(int irq, void *dev_id);
+void avs_dsp_process_response(struct avs_dev *adev, u64 header);
+int avs_dsp_send_msg_timeout(struct avs_dev *adev,
+			     struct avs_ipc_msg *request,
+			     struct avs_ipc_msg *reply, int timeout);
+int avs_dsp_send_msg(struct avs_dev *adev,
+		     struct avs_ipc_msg *request, struct avs_ipc_msg *reply);
+int avs_dsp_send_rom_msg_timeout(struct avs_dev *adev,
+				 struct avs_ipc_msg *request, int timeout);
+int avs_dsp_send_rom_msg(struct avs_dev *adev, struct avs_ipc_msg *request);
+void avs_dsp_interrupt_control(struct avs_dev *adev, bool enable);
+int avs_ipc_init(struct avs_ipc *ipc, struct device *dev);
+void avs_ipc_block(struct avs_ipc *ipc);
+
 #endif /* __SOUND_SOC_INTEL_AVS_H */