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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 NXP
*/
#include <linux/clk.h>
#include <linux/devfreq.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/pm_opp.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
struct imx_bus {
struct devfreq_dev_profile profile;
struct devfreq *devfreq;
struct clk *clk;
struct platform_device *icc_pdev;
};
static int imx_bus_target(struct device *dev,
unsigned long *freq, u32 flags)
{
struct dev_pm_opp *new_opp;
int ret;
new_opp = devfreq_recommended_opp(dev, freq, flags);
if (IS_ERR(new_opp)) {
ret = PTR_ERR(new_opp);
dev_err(dev, "failed to get recommended opp: %d\n", ret);
return ret;
}
dev_pm_opp_put(new_opp);
return dev_pm_opp_set_rate(dev, *freq);
}
static int imx_bus_get_cur_freq(struct device *dev, unsigned long *freq)
{
struct imx_bus *priv = dev_get_drvdata(dev);
*freq = clk_get_rate(priv->clk);
return 0;
}
static void imx_bus_exit(struct device *dev)
{
struct imx_bus *priv = dev_get_drvdata(dev);
dev_pm_opp_of_remove_table(dev);
platform_device_unregister(priv->icc_pdev);
}
/* imx_bus_init_icc() - register matching icc provider if required */
static int imx_bus_init_icc(struct device *dev)
{
struct imx_bus *priv = dev_get_drvdata(dev);
const char *icc_driver_name;
if (!of_get_property(dev->of_node, "#interconnect-cells", 0))
return 0;
if (!IS_ENABLED(CONFIG_INTERCONNECT_IMX)) {
dev_warn(dev, "imx interconnect drivers disabled\n");
return 0;
}
icc_driver_name = of_device_get_match_data(dev);
if (!icc_driver_name) {
dev_err(dev, "unknown interconnect driver\n");
return 0;
}
priv->icc_pdev = platform_device_register_data(
dev, icc_driver_name, -1, NULL, 0);
if (IS_ERR(priv->icc_pdev)) {
dev_err(dev, "failed to register icc provider %s: %ld\n",
icc_driver_name, PTR_ERR(priv->icc_pdev));
return PTR_ERR(priv->icc_pdev);
}
return 0;
}
static int imx_bus_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct imx_bus *priv;
const char *gov = DEVFREQ_GOV_USERSPACE;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/*
* Fetch the clock to adjust but don't explicitly enable.
*
* For imx bus clock clk_set_rate is safe no matter if the clock is on
* or off and some peripheral side-buses might be off unless enabled by
* drivers for devices on those specific buses.
*
* Rate adjustment on a disabled bus clock just takes effect later.
*/
priv->clk = devm_clk_get(dev, NULL);
if (IS_ERR(priv->clk)) {
ret = PTR_ERR(priv->clk);
dev_err(dev, "failed to fetch clk: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, priv);
ret = dev_pm_opp_of_add_table(dev);
if (ret < 0) {
dev_err(dev, "failed to get OPP table\n");
return ret;
}
priv->profile.target = imx_bus_target;
priv->profile.exit = imx_bus_exit;
priv->profile.get_cur_freq = imx_bus_get_cur_freq;
priv->profile.initial_freq = clk_get_rate(priv->clk);
priv->devfreq = devm_devfreq_add_device(dev, &priv->profile,
gov, NULL);
if (IS_ERR(priv->devfreq)) {
ret = PTR_ERR(priv->devfreq);
dev_err(dev, "failed to add devfreq device: %d\n", ret);
goto err;
}
ret = imx_bus_init_icc(dev);
if (ret)
goto err;
return 0;
err:
dev_pm_opp_of_remove_table(dev);
return ret;
}
static const struct of_device_id imx_bus_of_match[] = {
{ .compatible = "fsl,imx8mq-noc", .data = "imx8mq-interconnect", },
{ .compatible = "fsl,imx8mm-noc", .data = "imx8mm-interconnect", },
{ .compatible = "fsl,imx8mn-noc", .data = "imx8mn-interconnect", },
{ .compatible = "fsl,imx8m-noc", },
{ .compatible = "fsl,imx8m-nic", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, imx_bus_of_match);
static struct platform_driver imx_bus_platdrv = {
.probe = imx_bus_probe,
.driver = {
.name = "imx-bus-devfreq",
.of_match_table = imx_bus_of_match,
},
};
module_platform_driver(imx_bus_platdrv);
MODULE_DESCRIPTION("Generic i.MX bus frequency scaling driver");
MODULE_AUTHOR("Leonard Crestez <leonard.crestez@nxp.com>");
MODULE_LICENSE("GPL v2");
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