diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/firmware/imx/imx-dsp.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/firmware/imx/imx-dsp.c b/drivers/firmware/imx/imx-dsp.c new file mode 100644 index 000000000..0f656e419 --- /dev/null +++ b/drivers/firmware/imx/imx-dsp.c @@ -0,0 +1,192 @@ +// 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); + } +} + +struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *dsp_ipc, int idx) +{ + struct imx_dsp_chan *dsp_chan; + + if (idx >= DSP_MU_CHAN_NUM) + return ERR_PTR(-EINVAL); + + dsp_chan = &dsp_ipc->chans[idx]; + dsp_chan->ch = mbox_request_channel_byname(&dsp_chan->cl, dsp_chan->name); + return dsp_chan->ch; +} +EXPORT_SYMBOL(imx_dsp_request_channel); + +void imx_dsp_free_channel(struct imx_dsp_ipc *dsp_ipc, int idx) +{ + struct imx_dsp_chan *dsp_chan; + + if (idx >= DSP_MU_CHAN_NUM) + return; + + dsp_chan = &dsp_ipc->chans[idx]; + mbox_free_channel(dsp_chan->ch); +} +EXPORT_SYMBOL(imx_dsp_free_channel); + +static int imx_dsp_setup_channels(struct imx_dsp_ipc *dsp_ipc) +{ + struct device *dev = dsp_ipc->dev; + struct imx_dsp_chan *dsp_chan; + struct mbox_client *cl; + char *chan_name; + int ret; + int i, j; + + 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]; + dsp_chan->name = chan_name; + 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); + kfree(dsp_chan->name); + goto out; + } + + dev_dbg(dev, "request mbox chan %s\n", chan_name); + } + + return 0; +out: + for (j = 0; j < i; j++) { + dsp_chan = &dsp_ipc->chans[j]; + mbox_free_channel(dsp_chan->ch); + kfree(dsp_chan->name); + } + + return ret; +} + +static int imx_dsp_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct imx_dsp_ipc *dsp_ipc; + int ret; + + 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; + + dsp_ipc->dev = dev; + dev_set_drvdata(dev, dsp_ipc); + + ret = imx_dsp_setup_channels(dsp_ipc); + if (ret < 0) + return ret; + + dev_info(dev, "NXP i.MX DSP IPC initialized\n"); + + return 0; +} + +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); + kfree(dsp_chan->name); + } + + 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"); |