USB 2.0 PHY of R-Car Gen3 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 generic PHY driver.
Signed-off-by: Yoshihiro Shimoda <[email protected]> --- This patch is based on the latest linux-phy.git / next branch (commit id = 787f24543c4a599e5d9d311a3fce839ce87bbff0) I'm not sure this driver ss OK or not as a generic phy driver. So, I send this patch as RFC. .../bindings/phy/rcar-gen3-phy-usb2-clksel.txt | 58 +++++++++ drivers/phy/renesas/Kconfig | 8 ++ drivers/phy/renesas/Makefile | 1 + drivers/phy/renesas/phy-rcar-gen3-usb2-clksel.c | 129 +++++++++++++++++++++ 4 files changed, 196 insertions(+) create mode 100644 Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2-clksel.txt create mode 100644 drivers/phy/renesas/phy-rcar-gen3-usb2-clksel.c diff --git a/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2-clksel.txt b/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2-clksel.txt new file mode 100644 index 0000000..71b2f1b --- /dev/null +++ b/Documentation/devicetree/bindings/phy/rcar-gen3-phy-usb2-clksel.txt @@ -0,0 +1,58 @@ +* Renesas R-Car generation 3 USB 2.0 clock selector PHY + +This file provides information on what the device node for the R-Car generation +3 USB 2.0 clock selector PHY contains. + +If you connect an external clock to the USB_EXTAL pin, you can use the +"renesas,usb_extal_only" property for it. +If you connect an oscillator to both the USB_XTAL and USB_EXTAL, this module +is not needed because this is default setting. + +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-only" property. + +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-usb2-clksel-phy" if the device is a part of an + R8A7795 SoC. + "renesas,r8a7796-usb2-clksel-phy" if the device is a part of an + R8A7796 SoC. + + 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: clock phandle and specifier pair(s). +- #phy-cells: see phy-bindings.txt in the same directory, must be <0>. + +Optional properties: +- renesas,usb-extal-only: to connect a clock generator to USB_EXTAL pin. + +Example (R-Car H3): + + usb2_clksel_phy: usb-phy@e6590630 { + compatible = "renesas,r8a7795-usb2-clksel-phy", + "renesas,rcar-gen3-usb2-clksel-phy"; + reg = <0 0xe6590630 0 0x02>; + clocks = <&cpg CPG_MOD 703>; + renesas,usb-extal-only; + }; + + &ehci0 { + /* We should set usb2_clksel_phy into the first phys prop */ + phys = <&usb2_clksel_phy>, <&usb2_phy0>; + phy-names = "usb_clk", "usb"; + + status = "okay"; + }; diff --git a/drivers/phy/renesas/Kconfig b/drivers/phy/renesas/Kconfig index cb09245..a3b511b 100644 --- a/drivers/phy/renesas/Kconfig +++ b/drivers/phy/renesas/Kconfig @@ -16,6 +16,14 @@ config PHY_RCAR_GEN3_USB2 help Support for USB 2.0 PHY found on Renesas R-Car generation 3 SoCs. +config PHY_RCAR_GEN3_USB2_CLKSEL + tristate "Renesas R-Car generation 3 USB 2.0 clock selector PHY driver" + depends on ARCH_RENESAS + select GENERIC_PHY + help + Support for USB 2.0 clock selector PHY found on Renesas R-Car + generation 3 SoCs. + config PHY_RCAR_GEN3_USB3 tristate "Renesas R-Car generation 3 USB 3.0 PHY driver" depends on ARCH_RENESAS || COMPILE_TEST diff --git a/drivers/phy/renesas/Makefile b/drivers/phy/renesas/Makefile index 8b60259..26175b7 100644 --- a/drivers/phy/renesas/Makefile +++ b/drivers/phy/renesas/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_PHY_RCAR_GEN2) += phy-rcar-gen2.o obj-$(CONFIG_PHY_RCAR_GEN3_USB2) += phy-rcar-gen3-usb2.o +obj-$(CONFIG_PHY_RCAR_GEN3_USB2_CLKSEL) += phy-rcar-gen3-usb2-clksel.o obj-$(CONFIG_PHY_RCAR_GEN3_USB3) += phy-rcar-gen3-usb3.o diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2-clksel.c b/drivers/phy/renesas/phy-rcar-gen3-usb2-clksel.c new file mode 100644 index 0000000..e0e41c9 --- /dev/null +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2-clksel.c @@ -0,0 +1,129 @@ +/* + * Renesas R-Car Gen3 for USB2.0 clock selector PHY driver + * + * Copyright (C) 2017 Renesas Electronics Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.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 rcar_gen3_usb2_clksel { + void __iomem *base; + struct phy *phy; + bool usb_extal_only; +}; + +static int rcar_gen3_usb2_clksel_init(struct phy *p) +{ + struct rcar_gen3_usb2_clksel *r = phy_get_drvdata(p); + u16 val = readw(r->base + USB20_CLKSET0); + + dev_vdbg(&r->phy->dev, "%s: %d, %04x\n", __func__, r->usb_extal_only, + val); + + if (r->usb_extal_only && val != CLKSET0_EXTAL_ONLY) + writew(CLKSET0_EXTAL_ONLY, r->base + USB20_CLKSET0); + + return 0; +} + +static const struct phy_ops rcar_gen3_usb2_clksel_ops = { + .init = rcar_gen3_usb2_clksel_init, + .owner = THIS_MODULE, +}; + +static const struct of_device_id rcar_gen3_usb2_clksel_match_table[] = { + { .compatible = "renesas,rcar-gen3-usb2-clksel-phy" }, + { } +}; +MODULE_DEVICE_TABLE(of, rcar_gen3_usb2_clksel_match_table); + +static int rcar_gen3_usb2_clksel_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rcar_gen3_usb2_clksel *r; + struct phy_provider *provider; + struct resource *res; + int ret = 0; + + if (!dev->of_node) { + dev_err(dev, "This driver needs device tree\n"); + return -EINVAL; + } + + r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL); + if (!r) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + r->base = devm_ioremap_resource(dev, res); + if (IS_ERR(r->base)) + return PTR_ERR(r->base); + + /* + * devm_phy_create() will call pm_runtime_enable(&phy->dev); + * And then, phy-core will manage runtime pm for this device. + */ + pm_runtime_enable(dev); + + r->phy = devm_phy_create(dev, NULL, &rcar_gen3_usb2_clksel_ops); + if (IS_ERR(r->phy)) { + dev_err(dev, "Failed to create USB 2.0 clock selector PHY\n"); + ret = PTR_ERR(r->phy); + goto error; + } + + r->usb_extal_only = of_property_read_bool(dev->of_node, + "renesas,usb-extal-only"); + + platform_set_drvdata(pdev, r); + phy_set_drvdata(r->phy, r); + + provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); + if (IS_ERR(provider)) { + dev_err(dev, "Failed to register PHY provider\n"); + ret = PTR_ERR(provider); + goto error; + } + + return 0; + +error: + pm_runtime_disable(dev); + + return ret; +} + +static int rcar_gen3_usb2_clksel_remove(struct platform_device *pdev) +{ + pm_runtime_disable(&pdev->dev); + + return 0; +}; + +static struct platform_driver rcar_gen3_usb2_clksel_driver = { + .driver = { + .name = "phy_rcar_gen3_usb2_clksel", + .of_match_table = rcar_gen3_usb2_clksel_match_table, + }, + .probe = rcar_gen3_usb2_clksel_probe, + .remove = rcar_gen3_usb2_clksel_remove, +}; +module_platform_driver(rcar_gen3_usb2_clksel_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 2.0 clock selector PHY"); +MODULE_AUTHOR("Yoshihiro Shimoda <[email protected]>"); -- 1.9.1
