Hi, On Tuesday 04 October 2016 04:13 PM, Vivek Gautam wrote: > No-Op phy transceiver can be used on platforms that have > controllers which themselves provide PHY functionality and > there's no separate PHY controller available. > > This driver provides a basic skeleton for a nop-phy driver. > This can be further extended to add required features. > > Inspired by phy-generic driver in drivers/usb/phy. > > Signed-off-by: Vivek Gautam <vivek.gau...@codeaurora.org> > Cc: Kishon Vijay Abraham I <kis...@ti.com> > Cc: Felipe Balbi <ba...@kernel.org> > --- > > Hi Kishon, Felipe, > > This patch has been lying in my tree for sometime. > This introduces a skeletal nop-phy driver based on generic > phy framework. > I mainly use this driver when I have only one phy driver available > for testing for a controller that uses more than one phy. > > But this can be further extended to add any feature support for > controllers that don't have a separate PHY controller and that > themselves provide the PHY functionality, a purpose similar > to what drivers/usb/phy/phy-generic.c driver serves. > > Do you think we have a requirement for such a driver in the generic > phy layer? I hope this driver can do some good. > Let me know your comments on this. > > Thanks > Vivek > > Documentation/devicetree/bindings/phy/phy-nop.txt | 22 +++ > drivers/phy/Kconfig | 10 ++ > drivers/phy/Makefile | 1 + > drivers/phy/phy-nop.c | 193 > ++++++++++++++++++++++ > 4 files changed, 226 insertions(+) > create mode 100644 Documentation/devicetree/bindings/phy/phy-nop.txt > create mode 100644 drivers/phy/phy-nop.c > > diff --git a/Documentation/devicetree/bindings/phy/phy-nop.txt > b/Documentation/devicetree/bindings/phy/phy-nop.txt > new file mode 100644 > index 0000000..6cb6779 > --- /dev/null > +++ b/Documentation/devicetree/bindings/phy/phy-nop.txt > @@ -0,0 +1,22 @@ > +Generic No-Op PHY > +----------------- > + > +Required properties: > + - compatible: compatible list, contains "phy-nop". > + - #phy-cells: must be 0. > + > +Optional properties: > + - clocks: a list of phandles and clock-specifier pairs, > + one for each entry in clock-names. > + - clock-names: must be "main_clk" for phy core clock, > + "ref_clk" for phy reference clk. > + - resets: a list of phandles and reset controller specifier pairs, > + one for each entry in reset-names. > + - reset-names: must be "phy" for reset of phy block. > + - vdd-supply: Phandle to a regulator supply to PHY core block. > + > +Example: > + phy_nop: phy_nop { > + compatible = "phy-nop"; > + #phy-cells = <0>; > + };
I don't think this qualifies to be modeled as dt. device tree should try to represent HW and not workaround SW issues by creating dummy nodes. For such cases phy_optional_get should suffice? I'm more towards having a simple-phy, along the lines of [1] [1] -> https://patchwork.kernel.org/patch/8153691/ Thanks Kishon > diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig > index fe00f91..1923c4f 100644 > --- a/drivers/phy/Kconfig > +++ b/drivers/phy/Kconfig > @@ -489,4 +489,14 @@ config PHY_NS2_PCIE > help > Enable this to support the Broadcom Northstar2 PCIe PHY. > If unsure, say N. > + > +config PHY_NOP > + tristate "No-Operation PHY transceiver driver" > + depends on OF || COMPILE_TEST > + select GENERIC_PHY > + help > + Enable this to support the generic no-operation PHY > + transeiver. This driver can be used with consumers > + requiring a no-op phy for few of the handlers. > + > endmenu > diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile > index a534cf5..d6e0e60 100644 > --- a/drivers/phy/Makefile > +++ b/drivers/phy/Makefile > @@ -60,3 +60,4 @@ obj-$(CONFIG_PHY_PISTACHIO_USB) += > phy-pistachio-usb.o > obj-$(CONFIG_PHY_CYGNUS_PCIE) += phy-bcm-cygnus-pcie.o > obj-$(CONFIG_ARCH_TEGRA) += tegra/ > obj-$(CONFIG_PHY_NS2_PCIE) += phy-bcm-ns2-pcie.o > +obj-$(CONFIG_PHY_NOP) += phy-nop.o > diff --git a/drivers/phy/phy-nop.c b/drivers/phy/phy-nop.c > new file mode 100644 > index 0000000..cab01a1 > --- /dev/null > +++ b/drivers/phy/phy-nop.c > @@ -0,0 +1,193 @@ > +/* > + * Copyright (c) 2016, The Linux Foundation. All rights reserved. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 and > + * only version 2 as published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + */ > + > +#include <linux/clk.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/phy/phy.h> > +#include <linux/platform_device.h> > +#include <linux/reset.h> > + > +/** > + * struct phy_nop:- structure holding NOP PHY attributes. > + * > + * @dev: pointer to device. > + * @phy: pointer to generic phy. > + * @clk: pointer to phy clock. > + * @refclk: pointer to phy reference clock. > + * @vdd: vdd supply to the phy core block. > + * @rst: pointer to reset controller for the phy block. > + */ > +struct phy_nop { > + struct device *dev; > + struct phy *phy; > + struct clk *clk; > + struct clk *refclk; > + struct regulator *vdd; > + struct reset_control *rst; > +}; > + > +static int phy_nop_poweron(struct phy *generic_phy) > +{ > + struct phy_nop *phy = phy_get_drvdata(generic_phy); > + int ret = 0; > + > + if (phy->vdd) { > + ret = regulator_enable(phy->vdd); > + if (ret) { > + dev_err(phy->dev, "vdd enable failed: %d\n", ret); > + return ret; > + } > + } > + > + if (phy->clk) { > + ret = clk_prepare_enable(phy->clk); > + if (ret) { > + dev_err(phy->dev, "main clk enable failed: %d\n", ret); > + goto err_clk; > + } > + } > + > + if (phy->refclk) { > + ret = clk_prepare_enable(phy->refclk); > + if (ret) { > + dev_err(phy->dev, "ref clk enable failed: %d\n", ret); > + goto err_refclk; > + } > + } > + > + if (phy->rst) { > + ret = reset_control_deassert(phy->rst); > + if (ret) { > + dev_err(phy->dev, "phy reset deassert failed\n"); > + goto err_rst; > + } > + } > + > + return 0; > + > +err_rst: > + clk_disable_unprepare(phy->refclk); > +err_refclk: > + clk_disable_unprepare(phy->clk); > +err_clk: > + regulator_disable(phy->vdd); > + return ret; > +} > + > +static int phy_nop_poweroff(struct phy *generic_phy) > +{ > + struct phy_nop *phy = phy_get_drvdata(generic_phy); > + > + if (phy->rst) > + reset_control_assert(phy->rst); > + > + if (phy->clk) > + clk_disable_unprepare(phy->clk); > + if (phy->refclk) > + clk_disable_unprepare(phy->refclk); > + > + if (phy->vdd) > + regulator_disable(phy->vdd); > + > + return 0; > +} > + > +static const struct phy_ops phy_nop_gen_ops = { > + .power_on = phy_nop_poweron, > + .power_off = phy_nop_poweroff, > + .owner = THIS_MODULE, > +}; > + > +static int phy_nop_probe(struct platform_device *pdev) > +{ > + struct phy_nop *phy; > + struct phy *generic_phy; > + struct device *dev = &pdev->dev; > + struct phy_provider *phy_provider; > + int ret = 0; > + > + phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL); > + if (!phy) > + return -ENOMEM; > + phy->dev = dev; > + > + /* XXX: Do we need to request any clocks ? */ > + phy->clk = devm_clk_get(dev, "main_clk"); > + if (IS_ERR(phy->clk)) { > + dev_dbg(dev, "failed to get main_clk: %ld\n", > + PTR_ERR(phy->clk)); > + phy->clk = NULL; > + } > + phy->refclk = devm_clk_get(dev, "ref_clk"); > + if (IS_ERR(phy->refclk)) { > + dev_dbg(dev, "failed to get ref_clk: %ld\n", > + PTR_ERR(phy->refclk)); > + phy->refclk = NULL; > + } > + > + /* XXX: Do we need to request any regulators ? */ > + phy->vdd = devm_regulator_get(dev, "vdd"); > + if (IS_ERR(phy->vdd)) { > + dev_dbg(dev, "failed to get vdd for phy: %ld\n", > + PTR_ERR(phy->vdd)); > + phy->vdd = NULL; > + } > + > + /* XXX: Do we need to request any phy-reset ? */ > + phy->rst = devm_reset_control_get(dev, "phy"); > + if (IS_ERR(phy->rst)) { > + dev_dbg(dev, "failed to get phy core reset: %ld\n", > + PTR_ERR(phy->rst)); > + phy->rst = NULL; > + } > + > + generic_phy = devm_phy_create(dev, NULL, &phy_nop_gen_ops); > + if (IS_ERR(generic_phy)) { > + ret = PTR_ERR(generic_phy); > + dev_err(dev, "failed to create generic phy %d\n", ret); > + return ret; > + } > + phy->phy = generic_phy; > + phy_set_drvdata(generic_phy, phy); > + > + phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate); > + if (IS_ERR(phy_provider)) { > + ret = PTR_ERR(phy_provider); > + dev_err(dev, "failed to register phy %d\n", ret); > + } > + > + return ret; > +} > + > +static const struct of_device_id phy_nop_id_table[] = { > + { > + .compatible = "phy-nop", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, phy_nop_id_table); > + > +static struct platform_driver phy_nop_driver = { > + .probe = phy_nop_probe, > + .driver = { > + .name = "phy_nop", > + .of_match_table = of_match_ptr(phy_nop_id_table), > + }, > +}; > + > +module_platform_driver(phy_nop_driver); > + > +MODULE_DESCRIPTION("Generic No-op PHY driver"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html