linux-stable/include/linux/firmware/imx/dsp.h
Daniel Baluta 23d89aa0c2 firmware: imx-dsp: Export functions to request/free channels
In order to save power, we only need to request a channel
when the communication with the DSP active.

For this we export the following functions:
	- imx_dsp_request_channel, gets a channel with a given index
	- imx_dsp_free_channel, frees a channel with a given index

Notice that we still request channels at probe to support devices
that do not have PM callbacks implemented.

More explanations about why requesting a channel has an effect
on power savings:
 - requesting an mailbox channel will call mailbox's startup
   function.
 - startup function calls pm_runtime_get_sync which increments device
   usage count and will keep the device active. Specifically, mailbox
   clock will be always ON when a mailbox channel is requested.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Paul Olaru <paul.olaru@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-11-16 16:33:48 +08:00

77 lines
1.5 KiB
C

/* 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);
struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *ipc, int idx);
void imx_dsp_free_channel(struct imx_dsp_ipc *ipc, int idx);
#else
static inline int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc,
unsigned int chan_idx)
{
return -ENOTSUPP;
}
struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *ipc, int idx)
{
return ERR_PTR(-EOPNOTSUPP);
}
void imx_dsp_free_channel(struct imx_dsp_ipc *ipc, int idx) { }
#endif
#endif /* _IMX_DSP_IPC_H */