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/platform_device.h>
  14 #include <linux/slab.h>
  15
  16 /*
  17  * imx_dsp_ring_doorbell - triggers an interrupt on the other side (DSP)
  18  *
  19  * @dsp: DSP IPC handle
  20  * @chan_idx: index of the channel where to trigger the interrupt
  21  *
  22  * Returns non-negative value for success, negative value for error
  23  */
  24 int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc, unsigned int idx)
  25 {
  26         int ret;
  27         struct imx_dsp_chan *dsp_chan;
  28
  29         if (idx >= DSP_MU_CHAN_NUM)
  30                 return -EINVAL;
  31
  32         dsp_chan = &ipc->chans[idx];
  33         ret = mbox_send_message(dsp_chan->ch, NULL);
  34         if (ret < 0)
  35                 return ret;
  36
  37         return 0;
  38 }
  39 EXPORT_SYMBOL(imx_dsp_ring_doorbell);
  40
  41 /*
  42  * imx_dsp_handle_rx - rx callback used by imx mailbox
  43  *
  44  * @c: mbox client
  45  * @msg: message received
  46  *
  47  * Users of DSP IPC will need to privde handle_reply and handle_request
  48  * callbacks.
  49  */
  50 static void imx_dsp_handle_rx(struct mbox_client *c, void *msg)
  51 {
  52         struct imx_dsp_chan *chan = container_of(c, struct imx_dsp_chan, cl);
  53
  54         if (chan->idx == 0) {
  55                 chan->ipc->ops->handle_reply(chan->ipc);
  56         } else {
  57                 chan->ipc->ops->handle_request(chan->ipc);
  58                 imx_dsp_ring_doorbell(chan->ipc, 1);
  59         }
  60 }
  61
  62 struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
  63 {
  64         struct imx_dsp_chan *dsp_chan;
  65
  66         if (idx >= DSP_MU_CHAN_NUM)
  67                 return ERR_PTR(-EINVAL);
  68
  69         dsp_chan = &dsp_ipc->chans[idx];
  70         dsp_chan->ch = mbox_request_channel_byname(&dsp_chan->cl, dsp_chan->name);
  71         return dsp_chan->ch;
  72 }
  73 EXPORT_SYMBOL(imx_dsp_request_channel);
  74
  75 void imx_dsp_free_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
  76 {
  77         struct imx_dsp_chan *dsp_chan;
  78
  79         if (idx >= DSP_MU_CHAN_NUM)
  80                 return;
  81
  82         dsp_chan = &dsp_ipc->chans[idx];
  83         mbox_free_channel(dsp_chan->ch);
  84 }
  85 EXPORT_SYMBOL(imx_dsp_free_channel);
  86
  87 static int imx_dsp_setup_channels(struct imx_dsp_ipc *dsp_ipc)
  88 {
  89         struct device *dev = dsp_ipc->dev;
  90         struct imx_dsp_chan *dsp_chan;
  91         struct mbox_client *cl;
  92         char *chan_name;
  93         int ret;
  94         int i, j;
  95
  96         for (i = 0; i < DSP_MU_CHAN_NUM; i++) {
  97                 if (i < 2)
  98                         chan_name = kasprintf(GFP_KERNEL, "txdb%d", i);
  99                 else
 100                         chan_name = kasprintf(GFP_KERNEL, "rxdb%d", i - 2);
 101
 102                 if (!chan_name)
 103                         return -ENOMEM;
 104
 105                 dsp_chan = &dsp_ipc->chans[i];
 106                 dsp_chan->name = chan_name;
 107                 cl = &dsp_chan->cl;
 108                 cl->dev = dev;
 109                 cl->tx_block = false;
 110                 cl->knows_txdone = true;
 111                 cl->rx_callback = imx_dsp_handle_rx;
 112
 113                 dsp_chan->ipc = dsp_ipc;
 114                 dsp_chan->idx = i % 2;
 115                 dsp_chan->ch = mbox_request_channel_byname(cl, chan_name);
 116                 if (IS_ERR(dsp_chan->ch)) {
 117                         ret = PTR_ERR(dsp_chan->ch);
 118                         if (ret != -EPROBE_DEFER)
 119                                 dev_err(dev, "Failed to request mbox chan %s ret %d\n",
 120                                         chan_name, ret);
 121                         kfree(dsp_chan->name);
 122                         goto out;
 123                 }
 124
 125                 dev_dbg(dev, "request mbox chan %s\n", chan_name);
 126         }
 127
 128         return 0;
 129 out:
 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
 139 static 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
 163 static void 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
 178 static struct platform_driver imx_dsp_driver = {
 179         .driver = {
 180                 .name = "imx-dsp",
 181         },
 182         .probe = imx_dsp_probe,
 183         .remove = imx_dsp_remove,
 184 };
 185 builtin_platform_driver(imx_dsp_driver);
 186
 187 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
 188 MODULE_DESCRIPTION("IMX DSP IPC protocol driver");
 189 MODULE_LICENSE("GPL v2");