tegrakernel/kernel/nvidia/drivers/platform/tegra/tegra-aon-ivc-echo.c

149 lines
3.9 KiB
C

/*
* Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/device.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/tegra-aon.h>
#define TX_BLOCK_PERIOD 100
struct tegra_aon_ivc_echo_data {
struct mbox_client cl;
struct mbox_chan *mbox;
u32 frame_size;
char *rx_data;
};
static ssize_t tegra_aon_ivc_echo_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tegra_aon_ivc_echo_data *drvdata = dev_get_drvdata(dev);
memcpy(buf, drvdata->rx_data, drvdata->frame_size);
return drvdata->frame_size;
}
static ssize_t tegra_aon_ivc_echo_tx(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct tegra_aon_ivc_echo_data *drvdata = dev_get_drvdata(dev);
struct tegra_aon_mbox_msg msg;
int ret;
if (count > drvdata->frame_size) {
dev_err(dev, "Message is greater than the frame size %d\n",
drvdata->frame_size);
return -EINVAL;
}
msg.length = count;
msg.data = (void *)buf;
ret = mbox_send_message(drvdata->mbox, (void *)&msg);
if (ret < 0)
dev_err(dev, "mbox_send_message failed %d\n", ret);
return count;
}
static const DEVICE_ATTR(data_channel, S_IRUGO | S_IWUSR,
tegra_aon_ivc_echo_show, tegra_aon_ivc_echo_tx);
static void tegra_aon_ivc_echo_rx(struct mbox_client *cl, void *data)
{
struct tegra_aon_mbox_msg *msg = data;
struct tegra_aon_ivc_echo_data *drvdata = container_of(cl,
struct tegra_aon_ivc_echo_data,
cl);
memcpy(drvdata->rx_data, msg->data, drvdata->frame_size);
}
static int tegra_aon_ivc_echo_probe(struct platform_device *pdev)
{
int ret;
struct device *dev = &pdev->dev;
struct tegra_aon_ivc_echo_data *drvdata;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
dev_set_drvdata(dev, drvdata);
drvdata->cl.dev = dev;
drvdata->cl.tx_block = true;
drvdata->cl.tx_tout = TX_BLOCK_PERIOD;
drvdata->cl.knows_txdone = false;
drvdata->cl.rx_callback = tegra_aon_ivc_echo_rx;
drvdata->mbox = mbox_request_channel(&drvdata->cl, 0);
if (IS_ERR(drvdata->mbox)) {
ret = PTR_ERR(drvdata->mbox);
if (ret != -EPROBE_DEFER)
dev_err(dev, "mbox_request_channel failed. Error %d\n",
ret);
return ret;
}
drvdata->frame_size = mbox_get_max_txsize(drvdata->mbox);
if (drvdata->frame_size > PAGE_SIZE) {
dev_err(dev, "Faled to get a a valid frame_size\n");
ret = -EINVAL;
goto out;
}
drvdata->rx_data = devm_kzalloc(dev, drvdata->frame_size, GFP_KERNEL);
if (!drvdata->rx_data) {
ret = -ENOMEM;
goto out;
}
ret = device_create_file(dev, &dev_attr_data_channel);
if (ret) {
dev_err(dev, "Failed to create device file. Error %d\n", ret);
goto out;
}
return ret;
out:
mbox_free_channel(drvdata->mbox);
return ret;
}
static int tegra_aon_ivc_echo_remove(struct platform_device *pdev)
{
struct tegra_aon_ivc_echo_data *drvdata = dev_get_drvdata(&pdev->dev);
device_remove_file(&pdev->dev, &dev_attr_data_channel);
mbox_free_channel(drvdata->mbox);
return 0;
}
static const struct of_device_id tegra_aon_ivc_echo_match[] = {
{ .compatible = "nvidia,tegra186-aon-ivc-echo", },
{ },
};
MODULE_DEVICE_TABLE(of, tegra_aon_ivc_echo_match);
static struct platform_driver tegra_aon_ivc_echo_driver = {
.probe = tegra_aon_ivc_echo_probe,
.remove = tegra_aon_ivc_echo_remove,
.driver = {
.name = "tegra-aon-ivc-echo",
.of_match_table = tegra_aon_ivc_echo_match,
},
};
module_platform_driver(tegra_aon_ivc_echo_driver);