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path: root/drivers/firmware/imx/imx-scu.c
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Diffstat (limited to 'drivers/firmware/imx/imx-scu.c')
-rw-r--r--drivers/firmware/imx/imx-scu.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
new file mode 100644
index 0000000000..1dd4362ef9
--- /dev/null
+++ b/drivers/firmware/imx/imx-scu.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP
+ * Author: Dong Aisheng <aisheng.dong@nxp.com>
+ *
+ * Implementation of the SCU IPC functions using MUs (client side).
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/firmware/imx/ipc.h>
+#include <linux/firmware/imx/sci.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#define SCU_MU_CHAN_NUM 8
+#define MAX_RX_TIMEOUT (msecs_to_jiffies(3000))
+
+struct imx_sc_chan {
+ struct imx_sc_ipc *sc_ipc;
+
+ struct mbox_client cl;
+ struct mbox_chan *ch;
+ int idx;
+ struct completion tx_done;
+};
+
+struct imx_sc_ipc {
+ /* SCU uses 4 Tx and 4 Rx channels */
+ struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
+ struct device *dev;
+ struct mutex lock;
+ struct completion done;
+ bool fast_ipc;
+
+ /* temporarily store the SCU msg */
+ u32 *msg;
+ u8 rx_size;
+ u8 count;
+};
+
+/*
+ * This type is used to indicate error response for most functions.
+ */
+enum imx_sc_error_codes {
+ IMX_SC_ERR_NONE = 0, /* Success */
+ IMX_SC_ERR_VERSION = 1, /* Incompatible API version */
+ IMX_SC_ERR_CONFIG = 2, /* Configuration error */
+ IMX_SC_ERR_PARM = 3, /* Bad parameter */
+ IMX_SC_ERR_NOACCESS = 4, /* Permission error (no access) */
+ IMX_SC_ERR_LOCKED = 5, /* Permission error (locked) */
+ IMX_SC_ERR_UNAVAILABLE = 6, /* Unavailable (out of resources) */
+ IMX_SC_ERR_NOTFOUND = 7, /* Not found */
+ IMX_SC_ERR_NOPOWER = 8, /* No power */
+ IMX_SC_ERR_IPC = 9, /* Generic IPC error */
+ IMX_SC_ERR_BUSY = 10, /* Resource is currently busy/active */
+ IMX_SC_ERR_FAIL = 11, /* General I/O failure */
+ IMX_SC_ERR_LAST
+};
+
+static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
+ 0, /* IMX_SC_ERR_NONE */
+ -EINVAL, /* IMX_SC_ERR_VERSION */
+ -EINVAL, /* IMX_SC_ERR_CONFIG */
+ -EINVAL, /* IMX_SC_ERR_PARM */
+ -EACCES, /* IMX_SC_ERR_NOACCESS */
+ -EACCES, /* IMX_SC_ERR_LOCKED */
+ -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
+ -EEXIST, /* IMX_SC_ERR_NOTFOUND */
+ -EPERM, /* IMX_SC_ERR_NOPOWER */
+ -EPIPE, /* IMX_SC_ERR_IPC */
+ -EBUSY, /* IMX_SC_ERR_BUSY */
+ -EIO, /* IMX_SC_ERR_FAIL */
+};
+
+static struct imx_sc_ipc *imx_sc_ipc_handle;
+
+static inline int imx_sc_to_linux_errno(int errno)
+{
+ if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
+ return imx_sc_linux_errmap[errno];
+ return -EIO;
+}
+
+/*
+ * Get the default handle used by SCU
+ */
+int imx_scu_get_handle(struct imx_sc_ipc **ipc)
+{
+ if (!imx_sc_ipc_handle)
+ return -EPROBE_DEFER;
+
+ *ipc = imx_sc_ipc_handle;
+ return 0;
+}
+EXPORT_SYMBOL(imx_scu_get_handle);
+
+/* Callback called when the word of a message is ack-ed, eg read by SCU */
+static void imx_scu_tx_done(struct mbox_client *cl, void *mssg, int r)
+{
+ struct imx_sc_chan *sc_chan = container_of(cl, struct imx_sc_chan, cl);
+
+ complete(&sc_chan->tx_done);
+}
+
+static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
+{
+ struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
+ struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
+ struct imx_sc_rpc_msg *hdr;
+ u32 *data = msg;
+ int i;
+
+ if (!sc_ipc->msg) {
+ dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",
+ sc_chan->idx, *data);
+ return;
+ }
+
+ if (sc_ipc->fast_ipc) {
+ hdr = msg;
+ sc_ipc->rx_size = hdr->size;
+ sc_ipc->msg[0] = *data++;
+
+ for (i = 1; i < sc_ipc->rx_size; i++)
+ sc_ipc->msg[i] = *data++;
+
+ complete(&sc_ipc->done);
+
+ return;
+ }
+
+ if (sc_chan->idx == 0) {
+ hdr = msg;
+ sc_ipc->rx_size = hdr->size;
+ dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
+ if (sc_ipc->rx_size > 4)
+ dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
+ sc_ipc->rx_size);
+ }
+
+ sc_ipc->msg[sc_chan->idx] = *data;
+ sc_ipc->count++;
+
+ dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
+ sc_ipc->count, *data);
+
+ if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
+ complete(&sc_ipc->done);
+}
+
+static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
+{
+ struct imx_sc_rpc_msg hdr = *(struct imx_sc_rpc_msg *)msg;
+ struct imx_sc_chan *sc_chan;
+ u32 *data = msg;
+ int ret;
+ int size;
+ int i;
+
+ /* Check size */
+ if (hdr.size > IMX_SC_RPC_MAX_MSG)
+ return -EINVAL;
+
+ dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr.svc,
+ hdr.func, hdr.size);
+
+ size = sc_ipc->fast_ipc ? 1 : hdr.size;
+ for (i = 0; i < size; i++) {
+ sc_chan = &sc_ipc->chans[i % 4];
+
+ /*
+ * SCU requires that all messages words are written
+ * sequentially but linux MU driver implements multiple
+ * independent channels for each register so ordering between
+ * different channels must be ensured by SCU API interface.
+ *
+ * Wait for tx_done before every send to ensure that no
+ * queueing happens at the mailbox channel level.
+ */
+ if (!sc_ipc->fast_ipc) {
+ wait_for_completion(&sc_chan->tx_done);
+ reinit_completion(&sc_chan->tx_done);
+ }
+
+ ret = mbox_send_message(sc_chan->ch, &data[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * RPC command/response
+ */
+int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
+{
+ uint8_t saved_svc, saved_func;
+ struct imx_sc_rpc_msg *hdr;
+ int ret;
+
+ if (WARN_ON(!sc_ipc || !msg))
+ return -EINVAL;
+
+ mutex_lock(&sc_ipc->lock);
+ reinit_completion(&sc_ipc->done);
+
+ if (have_resp) {
+ sc_ipc->msg = msg;
+ saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;
+ saved_func = ((struct imx_sc_rpc_msg *)msg)->func;
+ }
+ sc_ipc->count = 0;
+ ret = imx_scu_ipc_write(sc_ipc, msg);
+ if (ret < 0) {
+ dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
+ goto out;
+ }
+
+ if (have_resp) {
+ if (!wait_for_completion_timeout(&sc_ipc->done,
+ MAX_RX_TIMEOUT)) {
+ dev_err(sc_ipc->dev, "RPC send msg timeout\n");
+ mutex_unlock(&sc_ipc->lock);
+ return -ETIMEDOUT;
+ }
+
+ /* response status is stored in hdr->func field */
+ hdr = msg;
+ ret = hdr->func;
+ /*
+ * Some special SCU firmware APIs do NOT have return value
+ * in hdr->func, but they do have response data, those special
+ * APIs are defined as void function in SCU firmware, so they
+ * should be treated as return success always.
+ */
+ if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&
+ (saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||
+ saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))
+ ret = 0;
+ }
+
+out:
+ sc_ipc->msg = NULL;
+ mutex_unlock(&sc_ipc->lock);
+
+ dev_dbg(sc_ipc->dev, "RPC SVC done\n");
+
+ return imx_sc_to_linux_errno(ret);
+}
+EXPORT_SYMBOL(imx_scu_call_rpc);
+
+static int imx_scu_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct imx_sc_ipc *sc_ipc;
+ struct imx_sc_chan *sc_chan;
+ struct mbox_client *cl;
+ char *chan_name;
+ struct of_phandle_args args;
+ int num_channel;
+ int ret;
+ int i;
+
+ sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
+ if (!sc_ipc)
+ return -ENOMEM;
+
+ ret = of_parse_phandle_with_args(pdev->dev.of_node, "mboxes",
+ "#mbox-cells", 0, &args);
+ if (ret)
+ return ret;
+
+ sc_ipc->fast_ipc = of_device_is_compatible(args.np, "fsl,imx8-mu-scu");
+
+ num_channel = sc_ipc->fast_ipc ? 2 : SCU_MU_CHAN_NUM;
+ for (i = 0; i < num_channel; i++) {
+ if (i < num_channel / 2)
+ chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
+ else
+ chan_name = kasprintf(GFP_KERNEL, "rx%d",
+ i - num_channel / 2);
+
+ if (!chan_name)
+ return -ENOMEM;
+
+ sc_chan = &sc_ipc->chans[i];
+ cl = &sc_chan->cl;
+ cl->dev = dev;
+ cl->tx_block = false;
+ cl->knows_txdone = true;
+ cl->rx_callback = imx_scu_rx_callback;
+
+ if (!sc_ipc->fast_ipc) {
+ /* Initial tx_done completion as "done" */
+ cl->tx_done = imx_scu_tx_done;
+ init_completion(&sc_chan->tx_done);
+ complete(&sc_chan->tx_done);
+ }
+
+ sc_chan->sc_ipc = sc_ipc;
+ sc_chan->idx = i % (num_channel / 2);
+ sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
+ if (IS_ERR(sc_chan->ch)) {
+ ret = PTR_ERR(sc_chan->ch);
+ dev_err_probe(dev, ret, "Failed to request mbox chan %s\n",
+ chan_name);
+ kfree(chan_name);
+ return ret;
+ }
+
+ dev_dbg(dev, "request mbox chan %s\n", chan_name);
+ /* chan_name is not used anymore by framework */
+ kfree(chan_name);
+ }
+
+ sc_ipc->dev = dev;
+ mutex_init(&sc_ipc->lock);
+ init_completion(&sc_ipc->done);
+
+ imx_sc_ipc_handle = sc_ipc;
+
+ ret = imx_scu_soc_init(dev);
+ if (ret)
+ dev_warn(dev, "failed to initialize SoC info: %d\n", ret);
+
+ ret = imx_scu_enable_general_irq_channel(dev);
+ if (ret)
+ dev_warn(dev,
+ "failed to enable general irq channel: %d\n", ret);
+
+ dev_info(dev, "NXP i.MX SCU Initialized\n");
+
+ return devm_of_platform_populate(dev);
+}
+
+static const struct of_device_id imx_scu_match[] = {
+ { .compatible = "fsl,imx-scu", },
+ { /* Sentinel */ }
+};
+
+static struct platform_driver imx_scu_driver = {
+ .driver = {
+ .name = "imx-scu",
+ .of_match_table = imx_scu_match,
+ },
+ .probe = imx_scu_probe,
+};
+
+static int __init imx_scu_driver_init(void)
+{
+ return platform_driver_register(&imx_scu_driver);
+}
+subsys_initcall_sync(imx_scu_driver_init);
+
+MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
+MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
+MODULE_LICENSE("GPL v2");