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: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>hifive-unleashed-5.1
Yoshihiro Shimoda
Geert Uytterhoeven
parent
d71e851d82
commit
311accb645
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@ -0,0 +1,55 @@
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* Renesas R-Car USB 2.0 clock selector
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This file provides information on what the device node for the R-Car USB 2.0
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clock selector.
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If you connect an external clock to the USB_EXTAL pin only, you should set
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the clock rate to "usb_extal" node only.
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If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module
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is not needed because this is default setting. (Of course, you can set the
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clock rates to both "usb_extal" and "usb_xtal" nodes.
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Case 1: An external clock connects to R-Car SoC
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+----------+ +--- R-Car ---------------------+
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|External |---|USB_EXTAL ---> all usb channels|
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|clock | |USB_XTAL |
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+----------+ +-------------------------------+
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In this case, we need this driver with "usb_extal" clock.
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Case 2: An oscillator connects to R-Car SoC
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+----------+ +--- R-Car ---------------------+
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|Oscillator|---|USB_EXTAL -+-> all usb channels|
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| |---|USB_XTAL --+ |
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+----------+ +-------------------------------+
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In this case, we don't need this selector.
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Required properties:
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- compatible: "renesas,r8a7795-rcar-usb2-clock-sel" if the device is a part of
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an R8A7795 SoC.
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"renesas,r8a7796-rcar-usb2-clock-sel" if the device if a part of
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an R8A7796 SoC.
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"renesas,rcar-gen3-usb2-clock-sel" for a generic R-Car Gen3
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compatible device.
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When compatible with the generic version, nodes must list the
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SoC-specific version corresponding to the platform first
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followed by the generic version.
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- reg: offset and length of the USB 2.0 clock selector register block.
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- clocks: A list of phandles and specifier pairs.
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- clock-names: Name of the clocks.
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- The functional clock must be "ehci_ohci"
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- The USB_EXTAL clock pin must be "usb_extal"
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- The USB_XTAL clock pin must be "usb_xtal"
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- #clock-cells: Must be 0
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Example (R-Car H3):
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usb2_clksel: clock-controller@e6590630 {
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compatible = "renesas,r8a77950-rcar-usb2-clock-sel",
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"renesas,rcar-gen3-usb2-clock-sel";
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reg = <0 0xe6590630 0 0x02>;
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clocks = <&cpg CPG_MOD 703>, <&usb_extal>, <&usb_xtal>;
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clock-names = "ehci_ohci", "usb_extal", "usb_xtal";
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#clock-cells = <0>;
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};
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@ -119,6 +119,11 @@ config CLK_RCAR_GEN3_CPG
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bool "R-Car Gen3 CPG clock support" if COMPILE_TEST
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select CLK_RENESAS_CPG_MSSR
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config CLK_RCAR_USB2_CLOCK_SEL
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bool "Renesas R-Car USB2 clock selector support"
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depends on ARCH_RENESAS || COMPILE_TEST
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help
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This is a driver for R-Car USB2 clock selector
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# Generic
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config CLK_RENESAS_CPG_MSSR
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@ -20,6 +20,7 @@ obj-$(CONFIG_CLK_SH73A0) += clk-sh73a0.o
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obj-$(CONFIG_CLK_RCAR_GEN2) += clk-rcar-gen2.o
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obj-$(CONFIG_CLK_RCAR_GEN2_CPG) += rcar-gen2-cpg.o
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obj-$(CONFIG_CLK_RCAR_GEN3_CPG) += rcar-gen3-cpg.o
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obj-$(CONFIG_CLK_RCAR_USB2_CLOCK_SEL) += rcar-usb2-clock-sel.o
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# Generic
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obj-$(CONFIG_CLK_RENESAS_CPG_MSSR) += renesas-cpg-mssr.o
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@ -0,0 +1,188 @@
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/*
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* Renesas R-Car USB2.0 clock selector
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*
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* Copyright (C) 2017 Renesas Electronics Corp.
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*
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* Based on renesas-cpg-mssr.c
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*
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* Copyright (C) 2015 Glider bvba
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*/
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#include <linux/clk.h>
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#include <linux/clk-provider.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/pm.h>
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#include <linux/pm_runtime.h>
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#include <linux/slab.h>
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#define USB20_CLKSET0 0x00
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#define CLKSET0_INTCLK_EN BIT(11)
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#define CLKSET0_PRIVATE BIT(0)
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#define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE)
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struct usb2_clock_sel_priv {
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void __iomem *base;
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struct clk_hw hw;
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bool extal;
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bool xtal;
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};
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#define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw)
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static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv)
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{
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u16 val = readw(priv->base + USB20_CLKSET0);
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pr_debug("%s: enter %d %d %x\n", __func__,
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priv->extal, priv->xtal, val);
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if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY)
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writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0);
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}
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static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv)
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{
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if (priv->extal && !priv->xtal)
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writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0);
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}
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static int usb2_clock_sel_enable(struct clk_hw *hw)
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{
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usb2_clock_sel_enable_extal_only(to_priv(hw));
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return 0;
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}
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static void usb2_clock_sel_disable(struct clk_hw *hw)
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{
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usb2_clock_sel_disable_extal_only(to_priv(hw));
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}
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/*
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* This module seems a mux, but this driver assumes a gate because
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* ehci/ohci platform drivers don't support clk_set_parent() for now.
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* If this driver acts as a gate, ehci/ohci-platform drivers don't need
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* any modification.
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*/
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static const struct clk_ops usb2_clock_sel_clock_ops = {
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.enable = usb2_clock_sel_enable,
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.disable = usb2_clock_sel_disable,
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};
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static const struct of_device_id rcar_usb2_clock_sel_match[] = {
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{ .compatible = "renesas,rcar-gen3-usb2-clock-sel" },
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{ }
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};
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static int rcar_usb2_clock_sel_suspend(struct device *dev)
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{
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struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
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usb2_clock_sel_disable_extal_only(priv);
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pm_runtime_put(dev);
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return 0;
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}
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static int rcar_usb2_clock_sel_resume(struct device *dev)
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{
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struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
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pm_runtime_get_sync(dev);
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usb2_clock_sel_enable_extal_only(priv);
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return 0;
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}
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static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev);
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of_clk_del_provider(dev->of_node);
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clk_hw_unregister(&priv->hw);
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pm_runtime_put(dev);
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pm_runtime_disable(dev);
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return 0;
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}
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static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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struct usb2_clock_sel_priv *priv;
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struct resource *res;
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struct clk *clk;
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struct clk_init_data init;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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priv->base = devm_ioremap_resource(dev, res);
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if (IS_ERR(priv->base))
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return PTR_ERR(priv->base);
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pm_runtime_enable(dev);
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pm_runtime_get_sync(dev);
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clk = devm_clk_get(dev, "usb_extal");
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if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
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priv->extal = !!clk_get_rate(clk);
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clk_disable_unprepare(clk);
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}
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clk = devm_clk_get(dev, "usb_xtal");
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if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
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priv->xtal = !!clk_get_rate(clk);
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clk_disable_unprepare(clk);
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}
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if (!priv->extal && !priv->xtal) {
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dev_err(dev, "This driver needs usb_extal or usb_xtal\n");
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return -ENOENT;
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}
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platform_set_drvdata(pdev, priv);
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dev_set_drvdata(dev, priv);
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init.name = "rcar_usb2_clock_sel";
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init.ops = &usb2_clock_sel_clock_ops;
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init.flags = 0;
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init.parent_names = NULL;
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init.num_parents = 0;
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priv->hw.init = &init;
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clk = clk_register(NULL, &priv->hw);
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
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}
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static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = {
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.suspend = rcar_usb2_clock_sel_suspend,
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.resume = rcar_usb2_clock_sel_resume,
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};
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static struct platform_driver rcar_usb2_clock_sel_driver = {
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.driver = {
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.name = "rcar-usb2-clock-sel",
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.of_match_table = rcar_usb2_clock_sel_match,
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.pm = &rcar_usb2_clock_sel_pm_ops,
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},
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.probe = rcar_usb2_clock_sel_probe,
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.remove = rcar_usb2_clock_sel_remove,
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};
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builtin_platform_driver(rcar_usb2_clock_sel_driver);
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MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver");
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MODULE_LICENSE("GPL v2");
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