Subject: Re: [RFC PATCH 2/8] phy: add driver for MediaTek pextp 10GE SerDes PHY

From: Vinod Koul <[email-masked]>
Date: Mon, 27 Nov 2023 18:46:06 +0530

On 09-11-23, 21:51, Daniel Golle wrote:
> Add driver for MediaTek's pextp 10 Gigabit/s Ethernet SerDes PHY which
> can be found in the MT7988 SoC.
> 
> The PHY can operates only in PHY_MODE_ETHERNET, the submode is one of
> PHY_INTERFACE_MODE_* corresponding to the supported modes:
> 
>  * USXGMII
>  * 10GBase-R
>  * 5GBase-R
>  * 2500Base-X
>  * 1000Base-X
>  * Cisco SGMII (MAC side)
> 
> In order to work-around a performance issue present on the first of
> two PEXTP present in MT7988 special tuning is applied which can be
> selected by adding the mediatek,usxgmii-performance-errata property to
> the device tree node.
> 
> There is no documentation what-so-ever for the pextp registers and
> this driver is based on a GPL licensed implementation found in
> MediaTek's SDK.
> 
> Signed-off-by: Daniel Golle <[email-masked]>
> ---
>  MAINTAINERS                          |   1 +
>  drivers/phy/mediatek/Kconfig         |  11 +
>  drivers/phy/mediatek/Makefile        |   1 +
>  drivers/phy/mediatek/phy-mtk-pextp.c | 355 +++++++++++++++++++++++++++
>  4 files changed, 368 insertions(+)
>  create mode 100644 drivers/phy/mediatek/phy-mtk-pextp.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 7b151710e8c58..6499acd8f3874 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13527,6 +13527,7 @@ L:	[email-masked]
>  S:	Maintained
>  F:	drivers/net/phy/mediatek-ge-soc.c
>  F:	drivers/net/phy/mediatek-ge.c
> +F:	drivers/phy/mediatek/phy-mediatek-pextp.c
>  
>  MEDIATEK I2C CONTROLLER DRIVER
>  M:	Qii Wang <[email-masked]>
> diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
> index 3125ecb5d119f..a7749a6d96541 100644
> --- a/drivers/phy/mediatek/Kconfig
> +++ b/drivers/phy/mediatek/Kconfig
> @@ -13,6 +13,17 @@ config PHY_MTK_PCIE
>  	  callback for PCIe GEN3 port, it supports software efuse
>  	  initialization.
>  
> +config PHY_MTK_PEXTP
> +	tristate "MediaTek PEXTP Driver"
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	depends on OF && OF_ADDRESS
> +	depends on HAS_IOMEM
> +	select GENERIC_PHY
> +	help
> +	  Say 'Y' here to add support for MediaTek pextp PHY driver.
> +	  The driver provides access to the Ethernet SerDes PHY supporting
> +	  various 1GE, 2.5GE, 5GE and 10GE modes.
> +
>  config PHY_MTK_TPHY
>  	tristate "MediaTek T-PHY Driver"
>  	depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
> index c9a50395533eb..ca60c7b9b02ac 100644
> --- a/drivers/phy/mediatek/Makefile
> +++ b/drivers/phy/mediatek/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_PHY_MTK_PCIE)		+= phy-mtk-pcie.o
>  obj-$(CONFIG_PHY_MTK_TPHY)		+= phy-mtk-tphy.o
>  obj-$(CONFIG_PHY_MTK_UFS)		+= phy-mtk-ufs.o
>  obj-$(CONFIG_PHY_MTK_XSPHY)		+= phy-mtk-xsphy.o
> +obj-$(CONFIG_PHY_MTK_PEXTP)		+= phy-mtk-pextp.o
>  
>  phy-mtk-hdmi-drv-y			:= phy-mtk-hdmi.o
>  phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt2701.o
> diff --git a/drivers/phy/mediatek/phy-mtk-pextp.c b/drivers/phy/mediatek/phy-mtk-pextp.c
> new file mode 100644
> index 0000000000000..272bff4f37a96
> --- /dev/null
> +++ b/drivers/phy/mediatek/phy-mtk-pextp.c
> @@ -0,0 +1,355 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* MediaTek 10GE SerDes PHY driver
> + *
> + * Copyright (c) 2023 Daniel Golle <[email-masked]>
> + * based on mtk_usxgmii.c found in MediaTek's SDK released under GPL-2.0
> + * Copyright (c) 2022 MediaTek Inc.
> + * Author: Henry Yen <[email-masked]>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/netdevice.h>
> +#include <linux/platform_device.h>
> +#include <linux/of.h>
> +#include <linux/io.h>
> +#include <linux/clk.h>
> +#include <linux/reset.h>
> +#include <linux/phy.h>
> +#include <linux/phy/phy.h>
> +
> +struct mtk_pextp_phy {
> +	void __iomem		*base;
> +	struct device		*dev;
> +	struct reset_control	*reset;
> +	struct clk		*clk;
> +	bool			da_war;
> +};
> +
> +static inline bool mtk_interface_mode_is_xgmii(phy_interface_t interface)
> +{
> +	switch (interface) {
> +	case PHY_INTERFACE_MODE_INTERNAL:
> +	case PHY_INTERFACE_MODE_USXGMII:
> +	case PHY_INTERFACE_MODE_10GBASER:
> +	case PHY_INTERFACE_MODE_5GBASER:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static void mtk_pextp_setup(struct mtk_pextp_phy *pextp, phy_interface_t interface)
> +{
> +	bool is_10g = (interface == PHY_INTERFACE_MODE_10GBASER ||
> +		       interface == PHY_INTERFACE_MODE_USXGMII);
> +	bool is_2p5g = (interface == PHY_INTERFACE_MODE_2500BASEX);
> +	bool is_5g = (interface == PHY_INTERFACE_MODE_5GBASER);
> +
> +	dev_dbg(pextp->dev, "setting up for mode %s\n", phy_modes(interface));
> +
> +	/* Setup operation mode */
> +	if (is_10g)
> +		iowrite32(0x00C9071C, pextp->base + 0x9024);

what are these magic numbers? also lower case hex values pls

> +	else
> +		iowrite32(0x00D9071C, pextp->base + 0x9024);
> +
> +	if (is_5g)
> +		iowrite32(0xAAA5A5AA, pextp->base + 0x2020);
> +	else
> +		iowrite32(0xAA8585AA, pextp->base + 0x2020);
> +
> +	if (is_2p5g || is_5g || is_10g) {
> +		iowrite32(0x0C020707, pextp->base + 0x2030);
> +		iowrite32(0x0E050F0F, pextp->base + 0x2034);
> +		iowrite32(0x00140032, pextp->base + 0x2040);
> +	} else {
> +		iowrite32(0x0C020207, pextp->base + 0x2030);
> +		iowrite32(0x0E05050F, pextp->base + 0x2034);
> +		iowrite32(0x00200032, pextp->base + 0x2040);
> +	}
> +
> +	if (is_2p5g || is_10g)
> +		iowrite32(0x00C014AA, pextp->base + 0x50F0);
> +	else if (is_5g)
> +		iowrite32(0x00C018AA, pextp->base + 0x50F0);
> +	else
> +		iowrite32(0x00C014BA, pextp->base + 0x50F0);
> +
> +	if (is_5g) {
> +		iowrite32(0x3777812B, pextp->base + 0x50E0);
> +		iowrite32(0x005C9CFF, pextp->base + 0x506C);
> +		iowrite32(0x9DFAFAFA, pextp->base + 0x5070);
> +		iowrite32(0x273F3F3F, pextp->base + 0x5074);
> +		iowrite32(0xA8883868, pextp->base + 0x5078);
> +		iowrite32(0x14661466, pextp->base + 0x507C);
> +	} else {
> +		iowrite32(0x3777C12B, pextp->base + 0x50E0);
> +		iowrite32(0x005F9CFF, pextp->base + 0x506C);
> +		iowrite32(0x9D9DFAFA, pextp->base + 0x5070);
> +		iowrite32(0x27273F3F, pextp->base + 0x5074);
> +		iowrite32(0xA7883C68, pextp->base + 0x5078);
> +		iowrite32(0x11661166, pextp->base + 0x507C);
> +	}
> +
> +	if (is_2p5g || is_10g) {
> +		iowrite32(0x0E000AAF, pextp->base + 0x5080);
> +		iowrite32(0x08080D0D, pextp->base + 0x5084);
> +		iowrite32(0x02030909, pextp->base + 0x5088);
> +	} else if (is_5g) {
> +		iowrite32(0x0E001ABF, pextp->base + 0x5080);
> +		iowrite32(0x080B0D0D, pextp->base + 0x5084);
> +		iowrite32(0x02050909, pextp->base + 0x5088);
> +	} else {
> +		iowrite32(0x0E000EAF, pextp->base + 0x5080);
> +		iowrite32(0x08080E0D, pextp->base + 0x5084);
> +		iowrite32(0x02030B09, pextp->base + 0x5088);
> +	}
> +
> +	if (is_5g) {
> +		iowrite32(0x0C000000, pextp->base + 0x50E4);
> +		iowrite32(0x04000000, pextp->base + 0x50E8);
> +	} else {
> +		iowrite32(0x0C0C0000, pextp->base + 0x50E4);
> +		iowrite32(0x04040000, pextp->base + 0x50E8);
> +	}
> +
> +	if (is_2p5g || mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x0F0F0C06, pextp->base + 0x50EC);
> +	else
> +		iowrite32(0x0F0F0606, pextp->base + 0x50EC);
> +
> +	if (is_5g) {
> +		iowrite32(0x50808C8C, pextp->base + 0x50A8);
> +		iowrite32(0x18000000, pextp->base + 0x6004);
> +	} else {
> +		iowrite32(0x506E8C8C, pextp->base + 0x50A8);
> +		iowrite32(0x18190000, pextp->base + 0x6004);
> +	}
> +
> +	if (is_10g)
> +		iowrite32(0x01423342, pextp->base + 0x00F8);
> +	else if (is_5g)
> +		iowrite32(0x00A132A1, pextp->base + 0x00F8);
> +	else if (is_2p5g)
> +		iowrite32(0x009C329C, pextp->base + 0x00F8);
> +	else
> +		iowrite32(0x00FA32FA, pextp->base + 0x00F8);
> +
> +	/* Force SGDT_OUT off and select PCS */
> +	if (mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x80201F20, pextp->base + 0x00F4);
> +	else
> +		iowrite32(0x80201F21, pextp->base + 0x00F4);
> +
> +	/* Force GLB_CKDET_OUT */
> +	iowrite32(0x00050C00, pextp->base + 0x0030);
> +
> +	/* Force AEQ on */
> +	iowrite32(0x02002800, pextp->base + 0x0070);
> +	ndelay(1020);
> +
> +	/* Setup DA default value */
> +	iowrite32(0x00000020, pextp->base + 0x30B0);
> +	iowrite32(0x00008A01, pextp->base + 0x3028);
> +	iowrite32(0x0000A884, pextp->base + 0x302C);
> +	iowrite32(0x00083002, pextp->base + 0x3024);
> +	if (mtk_interface_mode_is_xgmii(interface)) {
> +		iowrite32(0x00022220, pextp->base + 0x3010);
> +		iowrite32(0x0F020A01, pextp->base + 0x5064);
> +		iowrite32(0x06100600, pextp->base + 0x50B4);
> +		if (interface == PHY_INTERFACE_MODE_USXGMII)
> +			iowrite32(0x40704000, pextp->base + 0x3048);
> +		else
> +			iowrite32(0x47684100, pextp->base + 0x3048);
> +	} else {
> +		iowrite32(0x00011110, pextp->base + 0x3010);
> +		iowrite32(0x40704000, pextp->base + 0x3048);
> +	}
> +
> +	if (!mtk_interface_mode_is_xgmii(interface) && !is_2p5g)
> +		iowrite32(0x0000C000, pextp->base + 0x3064);
> +
> +	if (interface == PHY_INTERFACE_MODE_USXGMII) {
> +		iowrite32(0xA8000000, pextp->base + 0x3050);
> +		iowrite32(0x000000AA, pextp->base + 0x3054);
> +	} else if (mtk_interface_mode_is_xgmii(interface)) {
> +		iowrite32(0x00000000, pextp->base + 0x3050);
> +		iowrite32(0x00000000, pextp->base + 0x3054);
> +	} else {
> +		iowrite32(0xA8000000, pextp->base + 0x3050);
> +		iowrite32(0x000000AA, pextp->base + 0x3054);
> +	}
> +
> +	if (mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x00000F00, pextp->base + 0x306C);
> +	else if (is_2p5g)
> +		iowrite32(0x22000F00, pextp->base + 0x306C);
> +	else
> +		iowrite32(0x20200F00, pextp->base + 0x306C);
> +
> +	if (interface == PHY_INTERFACE_MODE_10GBASER && pextp->da_war)
> +		iowrite32(0x0007B400, pextp->base + 0xA008);
> +
> +	if (mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x00040000, pextp->base + 0xA060);
> +	else
> +		iowrite32(0x00050000, pextp->base + 0xA060);
> +
> +	if (is_10g)
> +		iowrite32(0x00000001, pextp->base + 0x90D0);
> +	else if (is_5g)
> +		iowrite32(0x00000003, pextp->base + 0x90D0);
> +	else if (is_2p5g)
> +		iowrite32(0x00000005, pextp->base + 0x90D0);
> +	else
> +		iowrite32(0x00000007, pextp->base + 0x90D0);
> +
> +	/* Release reset */
> +	iowrite32(0x0200E800, pextp->base + 0x0070);
> +	usleep_range(150, 500);
> +
> +	/* Switch to P0 */
> +	iowrite32(0x0200C111, pextp->base + 0x0070);
> +	ndelay(1020);
> +	iowrite32(0x0200C101, pextp->base + 0x0070);
> +	usleep_range(15, 50);
> +
> +	if (mtk_interface_mode_is_xgmii(interface)) {
> +		/* Switch to Gen3 */
> +		iowrite32(0x0202C111, pextp->base + 0x0070);
> +	} else {
> +		/* Switch to Gen2 */
> +		iowrite32(0x0201C111, pextp->base + 0x0070);
> +	}
> +	ndelay(1020);
> +	if (mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x0202C101, pextp->base + 0x0070);
> +	else
> +		iowrite32(0x0201C101, pextp->base + 0x0070);
> +	usleep_range(100, 500);
> +	iowrite32(0x00000030, pextp->base + 0x30B0);
> +	if (mtk_interface_mode_is_xgmii(interface))
> +		iowrite32(0x80201F00, pextp->base + 0x00F4);
> +	else
> +		iowrite32(0x80201F01, pextp->base + 0x00F4);
> +
> +	iowrite32(0x30000000, pextp->base + 0x3040);
> +	usleep_range(400, 1000);
> +}
> +
> +static int mtk_pextp_set_mode(struct phy *phy, enum phy_mode mode, int submode)
> +{
> +	struct mtk_pextp_phy *pextp = phy_get_drvdata(phy);
> +
> +	if (mode != PHY_MODE_ETHERNET)
> +		return -EINVAL;
> +
> +	switch (submode) {
> +	case PHY_INTERFACE_MODE_1000BASEX:
> +	case PHY_INTERFACE_MODE_2500BASEX:
> +	case PHY_INTERFACE_MODE_SGMII:
> +	case PHY_INTERFACE_MODE_5GBASER:
> +	case PHY_INTERFACE_MODE_10GBASER:
> +	case PHY_INTERFACE_MODE_USXGMII:
> +		mtk_pextp_setup(pextp, submode);
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int mtk_pextp_reset(struct phy *phy)
> +{
> +	struct mtk_pextp_phy *pextp = phy_get_drvdata(phy);
> +
> +	reset_control_assert(pextp->reset);
> +	usleep_range(100, 500);
> +	reset_control_deassert(pextp->reset);
> +	mdelay(10);
> +
> +	return 0;
> +}
> +
> +static int mtk_pextp_power_on(struct phy *phy)
> +{
> +	struct mtk_pextp_phy *pextp = phy_get_drvdata(phy);
> +
> +	return clk_prepare_enable(pextp->clk);
> +}
> +
> +static int mtk_pextp_power_off(struct phy *phy)
> +{
> +	struct mtk_pextp_phy *pextp = phy_get_drvdata(phy);
> +
> +	clk_disable_unprepare(pextp->clk);
> +
> +	return 0;
> +}
> +
> +static const struct phy_ops mtk_pextp_ops = {
> +	.power_on	= mtk_pextp_power_on,
> +	.power_off	= mtk_pextp_power_off,
> +	.set_mode	= mtk_pextp_set_mode,
> +	.reset		= mtk_pextp_reset,
> +	.owner		= THIS_MODULE,
> +};
> +
> +static int mtk_pextp_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct phy_provider *phy_provider;
> +	struct mtk_pextp_phy *pextp;
> +	struct phy *phy;
> +
> +	if (!np)
> +		return -ENODEV;
> +
> +	pextp = devm_kzalloc(&pdev->dev, sizeof(*pextp), GFP_KERNEL);
> +	if (!pextp)
> +		return -ENOMEM;
> +
> +	pextp->base = devm_of_iomap(&pdev->dev, np, 0, NULL);
> +	if (!pextp->base)
> +		return -EIO;
> +
> +	pextp->dev = &pdev->dev;
> +	pextp->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(pextp->clk))
> +		return PTR_ERR(pextp->clk);
> +
> +	pextp->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> +	if (IS_ERR(pextp->reset))
> +		return PTR_ERR(pextp->reset);
> +
> +	pextp->da_war = of_property_read_bool(np, "mediatek,usxgmii-performance-errata");
> +
> +	phy = devm_phy_create(&pdev->dev, NULL, &mtk_pextp_ops);
> +	if (IS_ERR(phy))
> +		return PTR_ERR(phy);
> +
> +	phy_set_drvdata(phy, pextp);
> +
> +	phy_provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
> +
> +	return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static const struct of_device_id mtk_pextp_match[] = {
> +	{ .compatible = "mediatek,mt7988-xfi-pextp", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, mtk_pextp_match);
> +
> +static struct platform_driver mtk_pextp_driver = {
> +	.probe = mtk_pextp_probe,
> +	.driver = {
> +		.name = "mtk-pextp",
> +		.of_match_table = mtk_pextp_match,
> +	},
> +};
> +module_platform_driver(mtk_pextp_driver);
> +
> +MODULE_DESCRIPTION("MediaTek pextp SerDes PHY driver");
> +MODULE_AUTHOR("Daniel Golle <[email-masked]>");
> +MODULE_LICENSE("GPL");
> -- 
> 2.42.1

-- 
~Vinod