Staging
v0.6.0
v0.6.0
https://github.com/torvalds/linux
Tip revision: 7e57714cd0ad2d5bb90e50b5096a0e671dec1ef3 authored by Linus Torvalds on 27 February 2022, 22:36:33 UTC
Linux 5.17-rc6
Linux 5.17-rc6
Tip revision: 7e57714
rcar-usb2-clock-sel.c
// SPDX-License-Identifier: GPL-2.0
/*
* Renesas R-Car USB2.0 clock selector
*
* Copyright (C) 2017 Renesas Electronics Corp.
*
* Based on renesas-cpg-mssr.c
*
* Copyright (C) 2015 Glider bvba
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/slab.h>
#define USB20_CLKSET0 0x00
#define CLKSET0_INTCLK_EN BIT(11)
#define CLKSET0_PRIVATE BIT(0)
#define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE)
static const struct clk_bulk_data rcar_usb2_clocks[] = {
{ .id = "ehci_ohci", },
{ .id = "hs-usb-if", },
};
struct usb2_clock_sel_priv {
void __iomem *base;
struct clk_hw hw;
struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)];
struct reset_control *rsts;
bool extal;
bool xtal;
};
#define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw)
static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv)
{
u16 val = readw(priv->base + USB20_CLKSET0);
pr_debug("%s: enter %d %d %x\n", __func__,
priv->extal, priv->xtal, val);
if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY)
writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0);
}
static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv)
{
if (priv->extal && !priv->xtal)
writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0);
}
static int usb2_clock_sel_enable(struct clk_hw *hw)
{
struct usb2_clock_sel_priv *priv = to_priv(hw);
int ret;
ret = reset_control_deassert(priv->rsts);
if (ret)
return ret;
ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);
if (ret) {
reset_control_assert(priv->rsts);
return ret;
}
usb2_clock_sel_enable_extal_only(priv);
return 0;
}
static void usb2_clock_sel_disable(struct clk_hw *hw)
{
struct usb2_clock_sel_priv *priv = to_priv(hw);
usb2_clock_sel_disable_extal_only(priv);
clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), priv->clks);
reset_control_assert(priv->rsts);
}
/*
* This module seems a mux, but this driver assumes a gate because
* ehci/ohci platform drivers don't support clk_set_parent() for now.
* If this driver acts as a gate, ehci/ohci-platform drivers don't need
* any modification.
*/
static const struct clk_ops usb2_clock_sel_clock_ops = {
.enable = usb2_clock_sel_enable,
.disable = usb2_clock_sel_disable,
};
static const struct of_device_id rcar_usb2_clock_sel_match[] = {
{ .compatible = "renesas,rcar-gen3-usb2-clock-sel" },
{ }
};
static int rcar_usb2_clock_sel_suspend(struct device *dev)
{
struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
usb2_clock_sel_disable_extal_only(priv);
pm_runtime_put(dev);
return 0;
}
static int rcar_usb2_clock_sel_resume(struct device *dev)
{
struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
pm_runtime_get_sync(dev);
usb2_clock_sel_enable_extal_only(priv);
return 0;
}
static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
of_clk_del_provider(dev->of_node);
pm_runtime_put(dev);
pm_runtime_disable(dev);
return 0;
}
static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct usb2_clock_sel_priv *priv;
struct clk *clk;
struct clk_init_data init = {};
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks));
ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), priv->clks);
if (ret < 0)
return ret;
priv->rsts = devm_reset_control_array_get_shared(dev);
if (IS_ERR(priv->rsts))
return PTR_ERR(priv->rsts);
clk = devm_clk_get(dev, "usb_extal");
if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
priv->extal = !!clk_get_rate(clk);
clk_disable_unprepare(clk);
}
clk = devm_clk_get(dev, "usb_xtal");
if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
priv->xtal = !!clk_get_rate(clk);
clk_disable_unprepare(clk);
}
if (!priv->extal && !priv->xtal) {
dev_err(dev, "This driver needs usb_extal or usb_xtal\n");
return -ENOENT;
}
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
platform_set_drvdata(pdev, priv);
dev_set_drvdata(dev, priv);
init.name = "rcar_usb2_clock_sel";
init.ops = &usb2_clock_sel_clock_ops;
priv->hw.init = &init;
ret = devm_clk_hw_register(dev, &priv->hw);
if (ret)
goto pm_put;
ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
if (ret)
goto pm_put;
return 0;
pm_put:
pm_runtime_put(dev);
pm_runtime_disable(dev);
return ret;
}
static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = {
.suspend = rcar_usb2_clock_sel_suspend,
.resume = rcar_usb2_clock_sel_resume,
};
static struct platform_driver rcar_usb2_clock_sel_driver = {
.driver = {
.name = "rcar-usb2-clock-sel",
.of_match_table = rcar_usb2_clock_sel_match,
.pm = &rcar_usb2_clock_sel_pm_ops,
},
.probe = rcar_usb2_clock_sel_probe,
.remove = rcar_usb2_clock_sel_remove,
};
builtin_platform_driver(rcar_usb2_clock_sel_driver);
MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver");
MODULE_LICENSE("GPL v2");