Commit 311accb6 authored by Yoshihiro Shimoda's avatar Yoshihiro Shimoda Committed by Geert Uytterhoeven

clk: renesas: rcar-usb2-clock-sel: Add R-Car USB 2.0 clock selector PHY

R-Car USB 2.0 controller can change the clock source from an oscillator
to an external clock via a register. So, this patch adds support
the clock source selector as a clock driver.
Signed-off-by: default avatarYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
parent d71e851d
* Renesas R-Car USB 2.0 clock selector
This file provides information on what the device node for the R-Car USB 2.0
clock selector.
If you connect an external clock to the USB_EXTAL pin only, you should set
the clock rate to "usb_extal" node only.
If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module
is not needed because this is default setting. (Of course, you can set the
clock rates to both "usb_extal" and "usb_xtal" nodes.
Case 1: An external clock connects to R-Car SoC
+----------+ +--- R-Car ---------------------+
|External |---|USB_EXTAL ---> all usb channels|
|clock | |USB_XTAL |
+----------+ +-------------------------------+
In this case, we need this driver with "usb_extal" clock.
Case 2: An oscillator connects to R-Car SoC
+----------+ +--- R-Car ---------------------+
|Oscillator|---|USB_EXTAL -+-> all usb channels|
| |---|USB_XTAL --+ |
+----------+ +-------------------------------+
In this case, we don't need this selector.
Required properties:
- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of
an R8A7795 SoC.
"renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of
an R8A7796 SoC.
"renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3
compatible device.
When compatible with the generic version, nodes must list the
SoC-specific version corresponding to the platform first
followed by the generic version.
- reg: offset and length of the USB 2.0 clock selector register block.
- clocks: A list of phandles and specifier pairs.
- clock-names: Name of the clocks.
- The functional clock must be "ehci_ohci"
- The USB_EXTAL clock pin must be "usb_extal"
- The USB_XTAL clock pin must be "usb_xtal"
- #clock-cells: Must be 0
Example (R-Car H3):
usb2_clksel: clock-controller@e6590630 {
compatible = "renesas,r8a77950-rcar-usb2-clock-sel",
"renesas,rcar-gen3-usb2-clock-sel";
reg = <0 0xe6590630 0 0x02>;
clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>;
clock-names = "ehci_ohci", "usb_extal", "usb_xtal";
#clock-cells = <0>;
};
...@@ -119,6 +119,11 @@ config CLK_RCAR_GEN3_CPG ...@@ -119,6 +119,11 @@ config CLK_RCAR_GEN3_CPG
bool "R-Car Gen3 CPG clock support" if COMPILE_TEST bool "R-Car Gen3 CPG clock support" if COMPILE_TEST
select CLK_RENESAS_CPG_MSSR select CLK_RENESAS_CPG_MSSR
config CLK_RCAR_USB2_CLOCK_SEL
bool "Renesas R-Car USB2 clock selector support"
depends on ARCH_RENESAS || COMPILE_TEST
help
This is a driver for R-Car USB2 clock selector
# Generic # Generic
config CLK_RENESAS_CPG_MSSR config CLK_RENESAS_CPG_MSSR
......
...@@ -20,6 +20,7 @@ obj-$(CONFIG_CLK_SH73A0) += clk-sh73a0.o ...@@ -20,6 +20,7 @@ obj-$(CONFIG_CLK_SH73A0) += clk-sh73a0.o
obj-$(CONFIG_CLK_RCAR_GEN2) += clk-rcar-gen2.o obj-$(CONFIG_CLK_RCAR_GEN2) += clk-rcar-gen2.o
obj-$(CONFIG_CLK_RCAR_GEN2_CPG) += rcar-gen2-cpg.o obj-$(CONFIG_CLK_RCAR_GEN2_CPG) += rcar-gen2-cpg.o
obj-$(CONFIG_CLK_RCAR_GEN3_CPG) += rcar-gen3-cpg.o obj-$(CONFIG_CLK_RCAR_GEN3_CPG) += rcar-gen3-cpg.o
obj-$(CONFIG_CLK_RCAR_USB2_CLOCK_SEL) += rcar-usb2-clock-sel.o
# Generic # Generic
obj-$(CONFIG_CLK_RENESAS_CPG_MSSR) += renesas-cpg-mssr.o obj-$(CONFIG_CLK_RENESAS_CPG_MSSR) += renesas-cpg-mssr.o
......
/*
* Renesas R-Car USB2.0 clock selector
*
* Copyright (C) 2017 Renesas Electronics Corp.
*
* Based on renesas-cpg-mssr.c
*
* Copyright (C) 2015 Glider bvba
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/init.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/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)
struct usb2_clock_sel_priv {
void __iomem *base;
struct clk_hw hw;
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)
{
usb2_clock_sel_enable_extal_only(to_priv(hw));
return 0;
}
static void usb2_clock_sel_disable(struct clk_hw *hw)
{
usb2_clock_sel_disable_extal_only(to_priv(hw));
}
/*
* 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;
struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);
of_clk_del_provider(dev->of_node);
clk_hw_unregister(&priv->hw);
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 resource *res;
struct clk *clk;
struct clk_init_data init;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
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;
}
platform_set_drvdata(pdev, priv);
dev_set_drvdata(dev, priv);
init.name = "rcar_usb2_clock_sel";
init.ops = &usb2_clock_sel_clock_ops;
init.flags = 0;
init.parent_names = NULL;
init.num_parents = 0;
priv->hw.init = &init;
clk = clk_register(NULL, &priv->hw);
if (IS_ERR(clk))
return PTR_ERR(clk);
return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
}
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");
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