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authorDaniel Baluta <daniel.baluta@nxp.com>2019-08-01 12:56:36 +0300
committerShawn Guo <shawnguo@kernel.org>2019-08-12 15:19:25 +0200
commitffbf23d50353915dc2622a3b7b4ddc678165f92d (patch)
tree7659b89235051a65d0df50eec8d165e07baa017f /include/linux/firmware
parent73feb4d0f8f14c5102bd46ce2255ff55d3d52db7 (diff)
firmware: imx: Add DSP IPC protocol interface
Some of i.MX8 processors (e.g i.MX8QM, i.MX8QXP) contain the Tensilica HiFi4 DSP for advanced pre- and post-audio processing. The communication between Host CPU and DSP firmware is taking place using a shared memory area for message passing and a dedicated Messaging Unit for notifications. DSP IPC protocol offers a doorbell interface using imx-mailbox API. We use 4 MU channels (2 x TXDB, 2 x RXDB) to implement a request-reply protocol. Connection 0 (txdb0, rxdb0): - Host writes messasge to shared memory [SHMEM] - Host sends a request [MU] - DSP handles request [SHMEM] - DSP sends reply [MU] Connection 1 (txdb1, rxdb1): - DSP writes a message to shared memory [SHMEM] - DSP sends a request [MU] - Host handles request [SHMEM] - Host sends reply [MU] The protocol interface will be used by a Host client to communicate with the DSP. First client will be the i.MX8 part from Sound Open Firmware infrastructure. The protocol offers the following interface: On Tx: - imx_dsp_ring_doorbell, will be called to notify the DSP that it needs to handle a request. On Rx: - clients need to provide two callbacks: .handle_reply .handle_request - the callbacks will be used by the protocol on notification arrival from DSP. Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com> Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Diffstat (limited to 'include/linux/firmware')
-rw-r--r--include/linux/firmware/imx/dsp.h67
1 files changed, 67 insertions, 0 deletions
diff --git a/include/linux/firmware/imx/dsp.h b/include/linux/firmware/imx/dsp.h
new file mode 100644
index 000000000000..7562099c9e46
--- /dev/null
+++ b/include/linux/firmware/imx/dsp.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2019 NXP
+ *
+ * Header file for the DSP IPC implementation
+ */
+
+#ifndef _IMX_DSP_IPC_H
+#define _IMX_DSP_IPC_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/mailbox_client.h>
+
+#define DSP_MU_CHAN_NUM 4
+
+struct imx_dsp_chan {
+ struct imx_dsp_ipc *ipc;
+ struct mbox_client cl;
+ struct mbox_chan *ch;
+ char *name;
+ int idx;
+};
+
+struct imx_dsp_ops {
+ void (*handle_reply)(struct imx_dsp_ipc *ipc);
+ void (*handle_request)(struct imx_dsp_ipc *ipc);
+};
+
+struct imx_dsp_ipc {
+ /* Host <-> DSP communication uses 2 txdb and 2 rxdb channels */
+ struct imx_dsp_chan chans[DSP_MU_CHAN_NUM];
+ struct device *dev;
+ struct imx_dsp_ops *ops;
+ void *private_data;
+};
+
+static inline void imx_dsp_set_data(struct imx_dsp_ipc *ipc, void *data)
+{
+ if (!ipc)
+ return;
+
+ ipc->private_data = data;
+}
+
+static inline void *imx_dsp_get_data(struct imx_dsp_ipc *ipc)
+{
+ if (!ipc)
+ return NULL;
+
+ return ipc->private_data;
+}
+
+#if IS_ENABLED(CONFIG_IMX_DSP)
+
+int imx_dsp_ring_doorbell(struct imx_dsp_ipc *dsp, unsigned int chan_idx);
+
+#else
+
+static inline int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc,
+ unsigned int chan_idx)
+{
+ return -ENOTSUPP;
+}
+
+#endif
+#endif /* _IMX_DSP_IPC_H */