LXR linux/drivers/firmware/imx/imx-dsp.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright 2019 NXP
   4 *  Author: Daniel Baluta <daniel.baluta@nxp.com>
   5 *
   6 * Implementation of the DSP IPC interface (host side)
   7 */
   8
   9#include <linux/firmware/imx/dsp.h>
  10#include <linux/kernel.h>
  11#include <linux/mailbox_client.h>
  12#include <linux/module.h>
  13#include <linux/of_platform.h>
  14#include <linux/platform_device.h>
  15#include <linux/slab.h>
  16
  17/*
  18 * imx_dsp_ring_doorbell - triggers an interrupt on the other side (DSP)
  19 *
  20 * @dsp: DSP IPC handle
  21 * @chan_idx: index of the channel where to trigger the interrupt
  22 *
  23 * Returns non-negative value for success, negative value for error
  24 */
  25int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc, unsigned int idx)
  26{
  27        int ret;
  28        struct imx_dsp_chan *dsp_chan;
  29
  30        if (idx >= DSP_MU_CHAN_NUM)
  31                return -EINVAL;
  32
  33        dsp_chan = &ipc->chans[idx];
  34        ret = mbox_send_message(dsp_chan->ch, NULL);
  35        if (ret < 0)
  36                return ret;
  37
  38        return 0;
  39}
  40EXPORT_SYMBOL(imx_dsp_ring_doorbell);
  41
  42/*
  43 * imx_dsp_handle_rx - rx callback used by imx mailbox
  44 *
  45 * @c: mbox client
  46 * @msg: message received
  47 *
  48 * Users of DSP IPC will need to privde handle_reply and handle_request
  49 * callbacks.
  50 */
  51static void imx_dsp_handle_rx(struct mbox_client *c, void *msg)
  52{
  53        struct imx_dsp_chan *chan = container_of(c, struct imx_dsp_chan, cl);
  54
  55        if (chan->idx == 0) {
  56                chan->ipc->ops->handle_reply(chan->ipc);
  57        } else {
  58                chan->ipc->ops->handle_request(chan->ipc);
  59                imx_dsp_ring_doorbell(chan->ipc, 1);
  60        }
  61}
  62
  63struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
  64{
  65        struct imx_dsp_chan *dsp_chan;
  66
  67        if (idx >= DSP_MU_CHAN_NUM)
  68                return ERR_PTR(-EINVAL);
  69
  70        dsp_chan = &dsp_ipc->chans[idx];
  71        dsp_chan->ch = mbox_request_channel_byname(&dsp_chan->cl, dsp_chan->name);
  72        return dsp_chan->ch;
  73}
  74EXPORT_SYMBOL(imx_dsp_request_channel);
  75
  76void imx_dsp_free_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
  77{
  78        struct imx_dsp_chan *dsp_chan;
  79
  80        if (idx >= DSP_MU_CHAN_NUM)
  81                return;
  82
  83        dsp_chan = &dsp_ipc->chans[idx];
  84        mbox_free_channel(dsp_chan->ch);
  85}
  86EXPORT_SYMBOL(imx_dsp_free_channel);
  87
  88static int imx_dsp_setup_channels(struct imx_dsp_ipc *dsp_ipc)
  89{
  90        struct device *dev = dsp_ipc->dev;
  91        struct imx_dsp_chan *dsp_chan;
  92        struct mbox_client *cl;
  93        char *chan_name;
  94        int ret;
  95        int i, j;
  96
  97        for (i = 0; i < DSP_MU_CHAN_NUM; i++) {
  98                if (i < 2)
  99                        chan_name = kasprintf(GFP_KERNEL, "txdb%d", i);
 100                else
 101                        chan_name = kasprintf(GFP_KERNEL, "rxdb%d", i - 2);
 102
 103                if (!chan_name)
 104                        return -ENOMEM;
 105
 106                dsp_chan = &dsp_ipc->chans[i];
 107                dsp_chan->name = chan_name;
 108                cl = &dsp_chan->cl;
 109                cl->dev = dev;
 110                cl->tx_block = false;
 111                cl->knows_txdone = true;
 112                cl->rx_callback = imx_dsp_handle_rx;
 113
 114                dsp_chan->ipc = dsp_ipc;
 115                dsp_chan->idx = i % 2;
 116                dsp_chan->ch = mbox_request_channel_byname(cl, chan_name);
 117                if (IS_ERR(dsp_chan->ch)) {
 118                        ret = PTR_ERR(dsp_chan->ch);
 119                        if (ret != -EPROBE_DEFER)
 120                                dev_err(dev, "Failed to request mbox chan %s ret %d\n",
 121                                        chan_name, ret);
 122                        goto out;
 123                }
 124
 125                dev_dbg(dev, "request mbox chan %s\n", chan_name);
 126        }
 127
 128        return 0;
 129out:
 130        for (j = 0; j < i; j++) {
 131                dsp_chan = &dsp_ipc->chans[j];
 132                mbox_free_channel(dsp_chan->ch);
 133                kfree(dsp_chan->name);
 134        }
 135
 136        return ret;
 137}
 138
 139static int imx_dsp_probe(struct platform_device *pdev)
 140{
 141        struct device *dev = &pdev->dev;
 142        struct imx_dsp_ipc *dsp_ipc;
 143        int ret;
 144
 145        device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
 146
 147        dsp_ipc = devm_kzalloc(dev, sizeof(*dsp_ipc), GFP_KERNEL);
 148        if (!dsp_ipc)
 149                return -ENOMEM;
 150
 151        dsp_ipc->dev = dev;
 152        dev_set_drvdata(dev, dsp_ipc);
 153
 154        ret = imx_dsp_setup_channels(dsp_ipc);
 155        if (ret < 0)
 156                return ret;
 157
 158        dev_info(dev, "NXP i.MX DSP IPC initialized\n");
 159
 160        return 0;
 161}
 162
 163static int imx_dsp_remove(struct platform_device *pdev)
 164{
 165        struct imx_dsp_chan *dsp_chan;
 166        struct imx_dsp_ipc *dsp_ipc;
 167        int i;
 168
 169        dsp_ipc = dev_get_drvdata(&pdev->dev);
 170
 171        for (i = 0; i < DSP_MU_CHAN_NUM; i++) {
 172                dsp_chan = &dsp_ipc->chans[i];
 173                mbox_free_channel(dsp_chan->ch);
 174                kfree(dsp_chan->name);
 175        }
 176
 177        return 0;
 178}
 179
 180static struct platform_driver imx_dsp_driver = {
 181        .driver = {
 182                .name = "imx-dsp",
 183        },
 184        .probe = imx_dsp_probe,
 185        .remove = imx_dsp_remove,
 186};
 187builtin_platform_driver(imx_dsp_driver);
 188
 189MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
 190MODULE_DESCRIPTION("IMX DSP IPC protocol driver");
 191MODULE_LICENSE("GPL v2");
 192