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// 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/types.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_platform.h>
#include <linux/platform_device.h>
#define SCU_MU_CHAN_NUM 8
#define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
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)
{
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;
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;
}
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);
if (ret != -EPROBE_DEFER)
dev_err(dev, "Failed to request mbox chan %s ret %d\n",
chan_name, ret);
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_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,
};
builtin_platform_driver(imx_scu_driver);
MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
MODULE_LICENSE("GPL v2");