Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/firmware/imx/imx-dsp.c b/drivers/firmware/imx/imx-dsp.c
new file mode 100644
index 0000000..a43d2db
--- /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");