From ffbf23d50353915dc2622a3b7b4ddc678165f92d Mon Sep 17 00:00:00 2001 From: Daniel Baluta Date: Thu, 1 Aug 2019 12:56:36 +0300 Subject: [PATCH] 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 Reviewed-by: Oleksij Rempel Signed-off-by: Shawn Guo --- drivers/firmware/imx/Kconfig | 11 +++ drivers/firmware/imx/Makefile | 1 + drivers/firmware/imx/imx-dsp.c | 155 +++++++++++++++++++++++++++++++ include/linux/firmware/imx/dsp.h | 67 +++++++++++++ 4 files changed, 234 insertions(+) create mode 100644 drivers/firmware/imx/imx-dsp.c create mode 100644 include/linux/firmware/imx/dsp.h diff --git a/drivers/firmware/imx/Kconfig b/drivers/firmware/imx/Kconfig index 42b566f8903f..0dbee32da4c6 100644 --- a/drivers/firmware/imx/Kconfig +++ b/drivers/firmware/imx/Kconfig @@ -1,4 +1,15 @@ # SPDX-License-Identifier: GPL-2.0-only +config IMX_DSP + bool "IMX DSP Protocol driver" + depends on IMX_MBOX + help + This enables DSP IPC protocol between host AP (Linux) + and the firmware running on DSP. + DSP exists on some i.MX8 processors (e.g i.MX8QM, i.MX8QXP). + + It acts like a doorbell. Client might use shared memory to + exchange information with DSP side. + config IMX_SCU bool "IMX SCU Protocol driver" depends on IMX_MBOX diff --git a/drivers/firmware/imx/Makefile b/drivers/firmware/imx/Makefile index 802c4ad8e8f9..08bc9ddfbdfb 100644 --- a/drivers/firmware/imx/Makefile +++ b/drivers/firmware/imx/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_IMX_DSP) += imx-dsp.o obj-$(CONFIG_IMX_SCU) += imx-scu.o misc.o imx-scu-irq.o obj-$(CONFIG_IMX_SCU_PD) += scu-pd.o diff --git a/drivers/firmware/imx/imx-dsp.c b/drivers/firmware/imx/imx-dsp.c new file mode 100644 index 000000000000..a43d2db5cbdb --- /dev/null +++ b/drivers/firmware/imx/imx-dsp.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright 2019 NXP + * Author: Daniel Baluta + * + * Implementation of the DSP IPC interface (host side) + */ + +#include +#include +#include +#include +#include +#include +#include + +/* + * imx_dsp_ring_doorbell - triggers an interrupt on the other side (DSP) + * + * @dsp: DSP IPC handle + * @chan_idx: index of the channel where to trigger the interrupt + * + * Returns non-negative value for success, negative value for error + */ +int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc, unsigned int idx) +{ + int ret; + struct imx_dsp_chan *dsp_chan; + + if (idx >= DSP_MU_CHAN_NUM) + return -EINVAL; + + dsp_chan = &ipc->chans[idx]; + ret = mbox_send_message(dsp_chan->ch, NULL); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(imx_dsp_ring_doorbell); + +/* + * imx_dsp_handle_rx - rx callback used by imx mailbox + * + * @c: mbox client + * @msg: message received + * + * Users of DSP IPC will need to privde handle_reply and handle_request + * callbacks. + */ +static void imx_dsp_handle_rx(struct mbox_client *c, void *msg) +{ + struct imx_dsp_chan *chan = container_of(c, struct imx_dsp_chan, cl); + + if (chan->idx == 0) { + chan->ipc->ops->handle_reply(chan->ipc); + } else { + chan->ipc->ops->handle_request(chan->ipc); + imx_dsp_ring_doorbell(chan->ipc, 1); + } +} + +static int imx_dsp_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct imx_dsp_ipc *dsp_ipc; + struct imx_dsp_chan *dsp_chan; + struct mbox_client *cl; + char *chan_name; + int ret; + int i, j; + + device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent); + + dsp_ipc = devm_kzalloc(dev, sizeof(*dsp_ipc), GFP_KERNEL); + if (!dsp_ipc) + return -ENOMEM; + + for (i = 0; i < DSP_MU_CHAN_NUM; i++) { + if (i < 2) + chan_name = kasprintf(GFP_KERNEL, "txdb%d", i); + else + chan_name = kasprintf(GFP_KERNEL, "rxdb%d", i - 2); + + if (!chan_name) + return -ENOMEM; + + dsp_chan = &dsp_ipc->chans[i]; + cl = &dsp_chan->cl; + cl->dev = dev; + cl->tx_block = false; + cl->knows_txdone = true; + cl->rx_callback = imx_dsp_handle_rx; + + dsp_chan->ipc = dsp_ipc; + dsp_chan->idx = i % 2; + dsp_chan->ch = mbox_request_channel_byname(cl, chan_name); + if (IS_ERR(dsp_chan->ch)) { + ret = PTR_ERR(dsp_chan->ch); + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to request mbox chan %s ret %d\n", + chan_name, ret); + goto out; + } + + dev_dbg(dev, "request mbox chan %s\n", chan_name); + /* chan_name is not used anymore by framework */ + kfree(chan_name); + } + + dsp_ipc->dev = dev; + + dev_set_drvdata(dev, dsp_ipc); + + dev_info(dev, "NXP i.MX DSP IPC initialized\n"); + + return devm_of_platform_populate(dev); +out: + kfree(chan_name); + for (j = 0; j < i; j++) { + dsp_chan = &dsp_ipc->chans[j]; + mbox_free_channel(dsp_chan->ch); + } + + return ret; +} + +static int imx_dsp_remove(struct platform_device *pdev) +{ + struct imx_dsp_chan *dsp_chan; + struct imx_dsp_ipc *dsp_ipc; + int i; + + dsp_ipc = dev_get_drvdata(&pdev->dev); + + for (i = 0; i < DSP_MU_CHAN_NUM; i++) { + dsp_chan = &dsp_ipc->chans[i]; + mbox_free_channel(dsp_chan->ch); + } + + return 0; +} + +static struct platform_driver imx_dsp_driver = { + .driver = { + .name = "imx-dsp", + }, + .probe = imx_dsp_probe, + .remove = imx_dsp_remove, +}; +builtin_platform_driver(imx_dsp_driver); + +MODULE_AUTHOR("Daniel Baluta "); +MODULE_DESCRIPTION("IMX DSP IPC protocol driver"); +MODULE_LICENSE("GPL v2"); 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 +#include +#include + +#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 */