Hi Shawn,

Can you please have a look at this when you have some time?

Basically, we need this patch for imx8 SOF Linux driver:

https://github.com/thesofproject/linux/pull/1048

I already got:

Reviewed-by: Oleksij Rempel o.rempel@pengutronix.de

For an older version of this patch.

thanks, Daniel.

On Thu, Aug 1, 2019 at 1:02 PM Daniel Baluta daniel.baluta@nxp.com wrote:

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

Changes since v3: - Added remove function

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 daniel.baluta@nxp.com
• • Implementation of the DSP IPC interface (host side)
• */

+#include <linux/firmware/imx/dsp.h> +#include <linux/kernel.h> +#include <linux/mailbox_client.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h>

+/*

• • 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 daniel.baluta@nxp.com"); +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 <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 */

2.17.1