Date:   Wed, 13 May 2020 08:16:19 +0530
From:   Kishon Vijay Abraham I <kishon@...com>
To:     Laurent Pinchart <laurent.pinchart@...asonboard.com>
CC:     <linux-kernel@...r.kernel.org>,
        Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>,
        Michal Simek <michal.simek@...inx.com>,
        Vinod Koul <vkoul@...nel.org>
Subject: Re: [PATCH v7 2/3] phy: zynqmp: Add PHY driver for the Xilinx ZynqMP
 Gigabit Transceiver

Hi Laurent,

On 5/8/2020 6:23 AM, Laurent Pinchart wrote:
> Hi Kishon,
> 
> On Thu, May 07, 2020 at 10:14:45AM +0530, Kishon Vijay Abraham I wrote:
>> On 4/2/2020 3:40 AM, Laurent Pinchart wrote:
>>> From: Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>
>>>
>>> Xilinx ZynqMP SoCs have a Gigabit Transceiver with four lanes. All the
>>> high speed peripherals such as USB, SATA, PCIE, Display Port and
>>> Ethernet SGMII can rely on any of the four GT lanes for PHY layer. This
>>> patch adds driver for that ZynqMP GT core.
>>>
>>> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>
>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>
>>> ---
>>> Changes since v5:
>>>
>>> - Cleanup headers
>>> - Organize the code in sections
>>> - Constify data tables and structures
>>> - Allocate all PHY instances in one go
>>> - Add I/O accessors
>>> - Move DP-specific init to a separate function
>>> - Use devm_platform_ioremap_resource_byname()
>>> - Simplify acquisition of reset controllers
>>> - Implement .configure() PHY operation for DP
>>> - Implement .power_on() and .power_off() operations
>>> - Wait for PLL lock for DP PHY too
>>> - Remove USB core reset operations
>>> - Fix SGMII bus width settings
>>> - Update copyright notice and authors list
>>> - Disable error messages on probe deferral
>>> - Update reset names to new DT bindings
>>> - Update to removal of subnodes in new DT bindings
>>> - Handle reference clocks through CCF
>>> - Add MAINTAINERS entry
>>> - Drop reset handling
>>> - Split TX term fix to separate function
>>> - Remove unused registers
>>> ---
>>>  MAINTAINERS              |   9 +
>>>  drivers/phy/Kconfig      |   8 +
>>>  drivers/phy/Makefile     |   1 +
>>>  drivers/phy/phy-zynqmp.c | 995 +++++++++++++++++++++++++++++++++++++++
>>
>> Better to add a xilinx directory for this driver.
> 
> OK.
> 
>>>  4 files changed, 1013 insertions(+)
>>>  create mode 100644 drivers/phy/phy-zynqmp.c
>>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 07293073c4f6..19e630fcaf62 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -18406,6 +18406,15 @@ F:	Documentation/devicetree/bindings/dma/xilinx/xlnx,zynqmp-dpdma.yaml
>>>  F:	drivers/dma/xilinx/xilinx_dpdma.c
>>>  F:	include/dt-bindings/dma/xlnx-zynqmp-dpdma.h
>>>  
>>> +XILINX ZYNQMP GSPTR PHY DRIVER
>>
>> Looks like a typo here,  rest of the place seems to use PSGTR
> 
> Good catch. Will fix it.
> 
>>> +M:	Anurag Kumar Vulisha <anurag.kumar.vulisha@...inx.com>
>>> +M:	Laurent Pinchart <laurent.pinchart@...asonboard.com>
>>> +L:	linux-kernel@...r.kernel.org
>>> +T:	git https://github.com/Xilinx/linux-xlnx.git
>>> +S:	Supported
>>> +F:	Documentation/devicetree/bindings/phy/xlnx,zynqmp-psgtr.yaml
>>> +F:	drivers/phy/phy-zynqmp.c
>>> +
>>>  XILLYBUS DRIVER
>>>  M:	Eli Billauer <eli.billauer@...il.com>
>>>  L:	linux-kernel@...r.kernel.org
>>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>>> index b3ed94b98d9b..b8251b9f3d87 100644
>>> --- a/drivers/phy/Kconfig
>>> +++ b/drivers/phy/Kconfig
>>> @@ -49,6 +49,14 @@ config PHY_XGENE
>>>  	help
>>>  	  This option enables support for APM X-Gene SoC multi-purpose PHY.
>>>  
>>> +config PHY_XILINX_ZYNQMP
>>> +	tristate "Xilinx ZynqMP PHY driver"
>>> +	depends on ARCH_ZYNQMP
>>> +	select GENERIC_PHY
>>> +	help
>>> +	  Enable this to support ZynqMP High Speed Gigabit Transceiver
>>> +	  that is part of ZynqMP SoC.
>>> +
>>>  source "drivers/phy/allwinner/Kconfig"
>>>  source "drivers/phy/amlogic/Kconfig"
>>>  source "drivers/phy/broadcom/Kconfig"
>>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>>> index 310c149a9df5..5dc7469f078b 100644
>>> --- a/drivers/phy/Makefile
>>> +++ b/drivers/phy/Makefile
>>> @@ -8,6 +8,7 @@ obj-$(CONFIG_GENERIC_PHY_MIPI_DPHY)	+= phy-core-mipi-dphy.o
>>>  obj-$(CONFIG_PHY_LPC18XX_USB_OTG)	+= phy-lpc18xx-usb-otg.o
>>>  obj-$(CONFIG_PHY_XGENE)			+= phy-xgene.o
>>>  obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
>>> +obj-$(CONFIG_PHY_XILINX_ZYNQMP)		+= phy-zynqmp.o
>>>  obj-$(CONFIG_ARCH_SUNXI)		+= allwinner/
>>>  obj-$(CONFIG_ARCH_MESON)		+= amlogic/
>>>  obj-$(CONFIG_ARCH_MEDIATEK)		+= mediatek/
>>> diff --git a/drivers/phy/phy-zynqmp.c b/drivers/phy/phy-zynqmp.c
>>> new file mode 100644
>>> index 000000000000..8ab99d6b9220
>>> --- /dev/null
>>> +++ b/drivers/phy/phy-zynqmp.c
>>> @@ -0,0 +1,995 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * phy-zynqmp.c - PHY driver for Xilinx ZynqMP GT.
>>> + *
>>> + * Copyright (C) 2018-20 Xilinx Inc.
>>> + *
>>> + * Author: Anurag Kumar Vulisha <anuragku@...inx.com>
>>> + * Author: Subbaraya Sundeep <sundeep.lkml@...il.com>
>>> + * Author: Laurent Pinchart <laurent.pinchart@...asonboard.com>
>>> + *
>>> + * This driver is tested for USB, SATA and Display Port currently.
>>> + * Other controllers PCIe and SGMII should also work but that is
>>> + * experimental as of now.
>>> + */
>>> +
>>> +#include <linux/clk.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/io.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/phy/phy.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/slab.h>
>>> +
>>> +#include <dt-bindings/phy/phy.h>
>>> +
>>> +/*
>>> + * Lane Registers
>>> + */
>>> +
>>> +/* TX De-emphasis parameters */
>>> +#define L0_TX_ANA_TM_18			0x0048
>>> +#define L0_TX_ANA_TM_118		0x01d8
>>> +#define L0_TX_ANA_TM_118_FORCE_17_0	BIT(0)
>>> +
>>> +/* DN Resistor calibration code parameters */
>>> +#define L0_TXPMA_ST_3			0x0b0c
>>> +#define L0_DN_CALIB_CODE		0x3f
>>> +
>>> +/* PMA control parameters */
>>> +#define L0_TXPMD_TM_45			0x0cb4
>>> +#define L0_TXPMD_TM_48			0x0cc0
>>> +#define L0_TXPMD_TM_45_OVER_DP_MAIN	BIT(0)
>>> +#define L0_TXPMD_TM_45_ENABLE_DP_MAIN	BIT(1)
>>> +#define L0_TXPMD_TM_45_OVER_DP_POST1	BIT(2)
>>> +#define L0_TXPMD_TM_45_ENABLE_DP_POST1	BIT(3)
>>> +#define L0_TXPMD_TM_45_OVER_DP_POST2	BIT(4)
>>> +#define L0_TXPMD_TM_45_ENABLE_DP_POST2	BIT(5)
>>> +
>>> +/* PCS control parameters */
>>> +#define L0_TM_DIG_6			0x106c
>>> +#define L0_TM_DIS_DESCRAMBLE_DECODER	0x0f
>>> +#define L0_TX_DIG_61			0x00f4
>>> +#define L0_TM_DISABLE_SCRAMBLE_ENCODER	0x0f
>>> +
>>> +/* PLL Test Mode register parameters */
>>> +#define L0_TM_PLL_DIG_37		0x2094
>>> +#define L0_TM_COARSE_CODE_LIMIT		0x10
>>> +
>>> +/* PLL SSC step size offsets */
>>> +#define L0_PLL_SS_STEPS_0_LSB		0x2368
>>> +#define L0_PLL_SS_STEPS_1_MSB		0x236c
>>> +#define L0_PLL_SS_STEP_SIZE_0_LSB	0x2370
>>> +#define L0_PLL_SS_STEP_SIZE_1		0x2374
>>> +#define L0_PLL_SS_STEP_SIZE_2		0x2378
>>> +#define L0_PLL_SS_STEP_SIZE_3_MSB	0x237c
>>> +#define L0_PLL_STATUS_READ_1		0x23e4
>>> +
>>> +/* SSC step size parameters */
>>> +#define STEP_SIZE_0_MASK		0xff
>>> +#define STEP_SIZE_1_MASK		0xff
>>> +#define STEP_SIZE_2_MASK		0xff
>>> +#define STEP_SIZE_3_MASK		0x3
>>> +#define STEP_SIZE_SHIFT			8
>>> +#define FORCE_STEP_SIZE			0x10
>>> +#define FORCE_STEPS			0x20
>>> +#define STEPS_0_MASK			0xff
>>> +#define STEPS_1_MASK			0x07
>>> +
>>> +/* Reference clock selection parameters */
>>> +#define L0_Ln_REF_CLK_SEL(n)		(0x2860 + (n) * 4)
>>> +#define L0_REF_CLK_SEL_MASK		0x8f
>>> +
>>> +/* Calibration digital logic parameters */
>>> +#define L3_TM_CALIB_DIG19		0xec4c
>>> +#define L3_CALIB_DONE_STATUS		0xef14
>>> +#define L3_TM_CALIB_DIG18		0xec48
>>> +#define L3_TM_CALIB_DIG19_NSW		0x07
>>> +#define L3_TM_CALIB_DIG18_NSW		0xe0
>>> +#define L3_TM_OVERRIDE_NSW_CODE         0x20
>>> +#define L3_CALIB_DONE			0x02
>>> +#define L3_NSW_SHIFT			5
>>> +#define L3_NSW_PIPE_SHIFT		4
>>> +#define L3_NSW_CALIB_SHIFT		3
>>> +
>>> +#define PHY_REG_OFFSET			0x4000
>>> +
>>> +/*
>>> + * Global Registers
>>> + */
>>> +
>>> +/* Refclk selection parameters */
>>> +#define PLL_REF_SEL(n)			(0x10000 + (n) * 4)
>>> +#define PLL_FREQ_MASK			0x1f
>>> +#define PLL_STATUS_LOCKED		0x10
>>> +
>>> +/* Inter Connect Matrix parameters */
>>> +#define ICM_CFG0			0x10010
>>> +#define ICM_CFG1			0x10014
>>> +#define ICM_CFG0_L0_MASK		0x07
>>> +#define ICM_CFG0_L1_MASK		0x70
>>> +#define ICM_CFG1_L2_MASK		0x07
>>> +#define ICM_CFG2_L3_MASK		0x70
>>> +#define ICM_CFG_SHIFT			4
>>> +
>>> +/* Inter Connect Matrix allowed protocols */
>>> +#define ICM_PROTOCOL_PD			0x0
>>> +#define ICM_PROTOCOL_PCIE		0x1
>>> +#define ICM_PROTOCOL_SATA		0x2
>>> +#define ICM_PROTOCOL_USB		0x3
>>> +#define ICM_PROTOCOL_DP			0x4
>>> +#define ICM_PROTOCOL_SGMII		0x5
>>> +
>>> +/* Test Mode common reset control  parameters */
>>> +#define TM_CMN_RST			0x10018
>>> +#define TM_CMN_RST_EN			0x1
>>> +#define TM_CMN_RST_SET			0x2
>>> +#define TM_CMN_RST_MASK			0x3
>>> +
>>> +/* Bus width parameters */
>>> +#define TX_PROT_BUS_WIDTH		0x10040
>>> +#define RX_PROT_BUS_WIDTH		0x10044
>>> +#define PROT_BUS_WIDTH_10		0x0
>>> +#define PROT_BUS_WIDTH_20		0x1
>>> +#define PROT_BUS_WIDTH_40		0x2
>>> +#define PROT_BUS_WIDTH_SHIFT		2
>>> +
>>> +/* Number of GT lanes */
>>> +#define NUM_LANES			4
>>> +
>>> +/* SIOU SATA control register */
>>> +#define SATA_CONTROL_OFFSET		0x0100
>>> +
>>> +/* Total number of controllers */
>>> +#define CONTROLLERS_PER_LANE		5
>>> +
>>> +/* Protocol Type parameters */
>>> +#define XPSGTR_TYPE_USB0		0  /* USB controller 0 */
>>> +#define XPSGTR_TYPE_USB1		1  /* USB controller 1 */
>>> +#define XPSGTR_TYPE_SATA_0		2  /* SATA controller lane 0 */
>>> +#define XPSGTR_TYPE_SATA_1		3  /* SATA controller lane 1 */
>>> +#define XPSGTR_TYPE_PCIE_0		4  /* PCIe controller lane 0 */
>>> +#define XPSGTR_TYPE_PCIE_1		5  /* PCIe controller lane 1 */
>>> +#define XPSGTR_TYPE_PCIE_2		6  /* PCIe controller lane 2 */
>>> +#define XPSGTR_TYPE_PCIE_3		7  /* PCIe controller lane 3 */
>>> +#define XPSGTR_TYPE_DP_0		8  /* Display Port controller lane 0 */
>>> +#define XPSGTR_TYPE_DP_1		9  /* Display Port controller lane 1 */
>>> +#define XPSGTR_TYPE_SGMII0		10 /* Ethernet SGMII controller 0 */
>>> +#define XPSGTR_TYPE_SGMII1		11 /* Ethernet SGMII controller 1 */
>>> +#define XPSGTR_TYPE_SGMII2		12 /* Ethernet SGMII controller 2 */
>>> +#define XPSGTR_TYPE_SGMII3		13 /* Ethernet SGMII controller 3 */
>>> +
>>> +/* Timeout values */
>>> +#define TIMEOUT_US			1000
>>> +
>>> +struct xpsgtr_dev;
>>> +
>>> +/**
>>> + * struct xpsgtr_ssc - structure to hold SSC settings for a lane
>>> + * @refclk_rate: PLL reference clock frequency
>>> + * @pll_ref_clk: value to be written to register for corresponding ref clk rate
>>> + * @steps: number of steps of SSC (Spread Spectrum Clock)
>>> + * @step_size: step size of each step
>>> + */
>>> +struct xpsgtr_ssc {
>>> +	u32 refclk_rate;
>>> +	u8  pll_ref_clk;
>>> +	u32 steps;
>>> +	u32 step_size;
>>> +};
>>> +
>>> +/**
>>> + * struct xpsgtr_phy - representation of a lane
>>> + * @phy: pointer to the kernel PHY device
>>> + * @type: controller which uses this lane
>>> + * @lane: lane number
>>> + * @protocol: protocol in which the lane operates
>>> + * @skip_phy_init: skip phy_init() if true
>>> + * @dev: pointer to the xpsgtr_dev instance
>>> + * @refclk: reference clock index
>>> + */
>>> +struct xpsgtr_phy {
>>> +	struct phy *phy;
>>> +	u8 type;
>>> +	u8 lane;
>>> +	u8 protocol;
>>> +	bool skip_phy_init;
>>> +	struct xpsgtr_dev *dev;
>>> +	unsigned int refclk;
>>> +};
>>> +
>>> +/**
>>> + * struct xpsgtr_dev - representation of a ZynMP GT device
>>> + * @dev: pointer to device
>>> + * @serdes: serdes base address
>>> + * @siou: siou base address
>>> + * @gtr_mutex: mutex for locking
>>> + * @phys: PHY lanes
>>> + * @refclk_sscs: spread spectrum settings for the reference clocks
>>> + * @tx_term_fix: fix for GT issue
>>> + * @saved_icm_cfg0: stored value of ICM CFG0 register
>>> + * @saved_icm_cfg1: stored value of ICM CFG1 register
>>> + */
>>> +struct xpsgtr_dev {
>>> +	struct device *dev;
>>> +	void __iomem *serdes;
>>> +	void __iomem *siou;
>>> +	struct mutex gtr_mutex; /* mutex for locking */
>>> +	struct xpsgtr_phy phys[NUM_LANES];
>>> +	const struct xpsgtr_ssc *refclk_sscs[NUM_LANES];
>>> +	bool tx_term_fix;
>>> +	unsigned int saved_icm_cfg0;
>>> +	unsigned int saved_icm_cfg1;
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>
>> The dash here is not commonly used. Please stick to default multi-line comment
>> style.
> 
> It's more common in some subsystems than others :-) No big deal, I'll
> drop it (even if I think it increases readability by clearly marking
> sections visually).
> 
>>> + * Configuration Data
>>> + */
>>> +
>>> +/* lookup table to hold all settings needed for a ref clock frequency */
>>> +static const struct xpsgtr_ssc ssc_lookup[] = {
>>> +	{  19200000, 0x05,  608, 264020 },
>>> +	{  20000000, 0x06,  634, 243454 },
>>> +	{  24000000, 0x07,  760, 168973 },
>>> +	{  26000000, 0x08,  824, 143860 },
>>> +	{  27000000, 0x09,  856,  86551 },
>>> +	{  38400000, 0x0a, 1218,  65896 },
>>> +	{  40000000, 0x0b,  634, 243454 },
>>> +	{  52000000, 0x0c,  824, 143860 },
>>> +	{ 100000000, 0x0d, 1058,  87533 },
>>> +	{ 108000000, 0x0e,  856,  86551 },
>>> +	{ 125000000, 0x0f,  992, 119497 },
>>> +	{ 135000000, 0x10, 1070,  55393 },
>>> +	{ 150000000, 0x11,  792, 187091 }
>>> +};
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * I/O Accessors
>>> + */
>>> +
>>> +static inline u32 xpsgtr_read(struct xpsgtr_dev *gtr_dev, u32 reg)
>>> +{
>>> +	return readl(gtr_dev->serdes + reg);
>>> +}
>>> +
>>> +static inline void xpsgtr_write(struct xpsgtr_dev *gtr_dev, u32 reg, u32 value)
>>> +{
>>> +	writel(value, gtr_dev->serdes + reg);
>>> +}
>>> +
>>> +static inline void xpsgtr_clr_set(struct xpsgtr_dev *gtr_dev, u32 reg,
>>> +				  u32 clr, u32 set)
>>> +{
>>> +	u32 value = xpsgtr_read(gtr_dev, reg);
>>> +
>>> +	value &= ~clr;
>>> +	value |= set;
>>> +	xpsgtr_write(gtr_dev, reg, value);
>>> +}
>>> +
>>> +static inline u32 xpsgtr_read_phy(struct xpsgtr_phy *gtr_phy, u32 reg)
>>> +{
>>> +	void __iomem *addr = gtr_phy->dev->serdes
>>> +			   + gtr_phy->lane * PHY_REG_OFFSET + reg;
>>> +
>>> +	return readl(addr);
>>> +}
>>> +
>>> +static inline void xpsgtr_write_phy(struct xpsgtr_phy *gtr_phy,
>>> +				    u32 reg, u32 value)
>>> +{
>>> +	void __iomem *addr = gtr_phy->dev->serdes
>>> +			   + gtr_phy->lane * PHY_REG_OFFSET + reg;
>>> +
>>> +	writel(value, addr);
>>> +}
>>> +
>>> +static inline void xpsgtr_clr_set_phy(struct xpsgtr_phy *gtr_phy,
>>> +				      u32 reg, u32 clr, u32 set)
>>> +{
>>> +	void __iomem *addr = gtr_phy->dev->serdes
>>> +			   + gtr_phy->lane * PHY_REG_OFFSET + reg;
>>> +
>>> +	writel((readl(addr) & ~clr) | set, addr);
>>> +}
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * Hardware Configuration
>>> + */
>>> +
>>> +/* Wait for the PLL to lock (with a timeout). */
>>> +static int xpsgtr_wait_pll_lock(struct phy *phy)
>>> +{
>>> +	struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
>>> +	struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>>> +	unsigned int timeout = TIMEOUT_US;
>>> +	int ret;
>>> +
>>> +	dev_dbg(gtr_dev->dev, "Waiting for PLL lock\n");
>>> +
>>> +	while (1) {
>>> +		u32 reg = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
>>> +
>>> +		if ((reg & PLL_STATUS_LOCKED) == PLL_STATUS_LOCKED) {
>>> +			ret = 0;
>>> +			break;
>>> +		}
>>> +
>>> +		if (--timeout == 0) {
>>> +			ret = -ETIMEDOUT;
>>> +			break;
>>> +		}
>>> +
>>> +		udelay(1);
>>> +	}
>>> +
>>> +	if (ret == -ETIMEDOUT)
>>> +		dev_err(gtr_dev->dev,
>>> +			"lane %u (type %u, protocol %u): PLL lock timeout\n",
>>> +			gtr_phy->lane, gtr_phy->type, gtr_phy->protocol);
>>> +
>>> +	return ret;
>>> +}
>>> +
>>> +/* Configure PLL and spread-sprectrum clock. */
>>> +static void xpsgtr_configure_pll(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	const struct xpsgtr_ssc *ssc;
>>> +	u32 step_size;
>>> +
>>> +	ssc = gtr_phy->dev->refclk_sscs[gtr_phy->refclk];
>>> +	step_size = ssc->step_size;
>>> +
>>> +	xpsgtr_clr_set(gtr_phy->dev, PLL_REF_SEL(gtr_phy->lane),
>>> +		       PLL_FREQ_MASK, ssc->pll_ref_clk);
>>> +
>>> +	/* Enable lane clock sharing, if required */
>>> +	if (gtr_phy->refclk != gtr_phy->lane) {
>>> +		/* Lane3 Ref Clock Selection Register */
>>> +		xpsgtr_clr_set(gtr_phy->dev, L0_Ln_REF_CLK_SEL(gtr_phy->lane),
>>> +			       L0_REF_CLK_SEL_MASK, 1 << gtr_phy->refclk);
>>> +	}
>>> +
>>> +	/* SSC step size [7:0] */
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_0_LSB,
>>> +			   STEP_SIZE_0_MASK, step_size & STEP_SIZE_0_MASK);
>>> +
>>> +	/* SSC step size [15:8] */
>>> +	step_size >>= STEP_SIZE_SHIFT;
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_1,
>>> +			   STEP_SIZE_1_MASK, step_size & STEP_SIZE_1_MASK);
>>> +
>>> +	/* SSC step size [23:16] */
>>> +	step_size >>= STEP_SIZE_SHIFT;
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_2,
>>> +			   STEP_SIZE_2_MASK, step_size & STEP_SIZE_2_MASK);
>>> +
>>> +	/* SSC steps [7:0] */
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEPS_0_LSB,
>>> +			   STEPS_0_MASK, ssc->steps & STEPS_0_MASK);
>>> +
>>> +	/* SSC steps [10:8] */
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEPS_1_MSB,
>>> +			   STEPS_1_MASK,
>>> +			   (ssc->steps >> STEP_SIZE_SHIFT) & STEPS_1_MASK);
>>> +
>>> +	/* SSC step size [24:25] */
>>> +	step_size >>= STEP_SIZE_SHIFT;
>>> +	xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_3_MSB,
>>> +			   STEP_SIZE_3_MASK, (step_size & STEP_SIZE_3_MASK) |
>>> +			   FORCE_STEP_SIZE | FORCE_STEPS);
>>> +}
>>> +
>>> +/* Configure the lane protocol. */
>>> +static void xpsgtr_lane_set_protocol(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>>> +	u8 protocol = gtr_phy->protocol;
>>> +
>>> +	switch (gtr_phy->lane) {
>>> +	case 0:
>>> +		xpsgtr_clr_set(gtr_dev, ICM_CFG0, ICM_CFG0_L0_MASK, protocol);
>>> +		break;
>>> +	case 1:
>>> +		xpsgtr_clr_set(gtr_dev, ICM_CFG0, ICM_CFG0_L1_MASK,
>>> +			       protocol << ICM_CFG_SHIFT);
>>> +		break;
>>> +	case 2:
>>> +		xpsgtr_clr_set(gtr_dev, ICM_CFG1, ICM_CFG0_L0_MASK, protocol);
>>> +		break;
>>> +	case 3:
>>> +		xpsgtr_clr_set(gtr_dev, ICM_CFG1, ICM_CFG0_L1_MASK,
>>> +			       protocol << ICM_CFG_SHIFT);
>>> +		break;
>>> +	default:
>>> +		/* We already checked 0 <= lane <= 3 */
>>> +		break;
>>> +	}
>>> +}
>>> +
>>> +/* Bypass (de)scrambler and 8b/10b decoder and encoder. */
>>> +static void xpsgtr_bypass_scrambler_8b10b(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	xpsgtr_write_phy(gtr_phy, L0_TM_DIG_6, L0_TM_DIS_DESCRAMBLE_DECODER);
>>> +	xpsgtr_write_phy(gtr_phy, L0_TX_DIG_61, L0_TM_DISABLE_SCRAMBLE_ENCODER);
>>> +}
>>> +
>>> +/* DP-specific initialization. */
>>> +static void xpsgtr_phy_init_dp(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	xpsgtr_write_phy(gtr_phy, L0_TXPMD_TM_45,
>>> +			 L0_TXPMD_TM_45_OVER_DP_MAIN |
>>> +			 L0_TXPMD_TM_45_ENABLE_DP_MAIN |
>>> +			 L0_TXPMD_TM_45_OVER_DP_POST1 |
>>> +			 L0_TXPMD_TM_45_OVER_DP_POST2 |
>>> +			 L0_TXPMD_TM_45_ENABLE_DP_POST2);
>>> +	xpsgtr_write_phy(gtr_phy, L0_TX_ANA_TM_118,
>>> +			 L0_TX_ANA_TM_118_FORCE_17_0);
>>> +}
>>> +
>>> +/* SATA-specific initialization. */
>>> +static void xpsgtr_phy_init_sata(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>>> +
>>> +	xpsgtr_bypass_scrambler_8b10b(gtr_phy);
>>> +
>>> +	writel(gtr_phy->lane, gtr_dev->siou + SATA_CONTROL_OFFSET);
>>> +}
>>
>> The cover letter mentions this has been tested with DP. Was it tested with SATA
>> and SGMII as well?
> 
> On the Xilinx downstream kernel only, as SATA and SGMII isn't available
> upstream yet.

Would prefer to merge only what is tested upstream. Are there plans of getting
SATA and SGMII upstream? Are the patches posted?
> 
>>> +
>>> +/* SGMII-specific initialization. */
>>> +static void xpsgtr_phy_init_sgmii(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>>> +
>>> +	/* Set SGMII protocol TX and RX bus width to 10 bits. */
>>> +	xpsgtr_write(gtr_dev, TX_PROT_BUS_WIDTH,
>>> +		     PROT_BUS_WIDTH_10 << (gtr_phy->lane * PROT_BUS_WIDTH_SHIFT));
>>> +	xpsgtr_write(gtr_dev, RX_PROT_BUS_WIDTH,
>>> +		     PROT_BUS_WIDTH_10 << (gtr_phy->lane * PROT_BUS_WIDTH_SHIFT));
>>> +
>>> +	xpsgtr_bypass_scrambler_8b10b(gtr_phy);
>>> +}
>>> +
>>> +/* Configure TX de-emphasis and margining for DP. */
>>> +static void xpsgtr_phy_configure_dp(struct xpsgtr_phy *gtr_phy, unsigned int pre,
>>> +				    unsigned int voltage)
>>> +{
>>> +	static const u8 voltage_swing[4][4] = {
>>> +		{ 0x2a, 0x27, 0x24, 0x20 },
>>> +		{ 0x27, 0x23, 0x20, 0xff },
>>> +		{ 0x24, 0x20, 0xff, 0xff },
>>> +		{ 0xff, 0xff, 0xff, 0xff }
>>> +	};
>>> +	static const u8 pre_emphasis[4][4] = {
>>> +		{ 0x02, 0x02, 0x02, 0x02 },
>>> +		{ 0x01, 0x01, 0x01, 0xff },
>>> +		{ 0x00, 0x00, 0xff, 0xff },
>>> +		{ 0xff, 0xff, 0xff, 0xff }
>>> +	};
>>> +
>>> +	xpsgtr_write_phy(gtr_phy, L0_TXPMD_TM_48, voltage_swing[pre][voltage]);
>>> +	xpsgtr_write_phy(gtr_phy, L0_TX_ANA_TM_18, pre_emphasis[pre][voltage]);
>>> +}
>>> +
>>> +/* -----------------------------------------------------------------------------
>>> + * PHY Operations
>>> + */
>>> +
>>> +static bool xpsgtr_phy_init_required(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	/*
>>> +	 * As USB may save the snapshot of the states during hibernation, doing
>>> +	 * phy_init() will put the USB controller into reset, resulting in the
>>> +	 * losing of the saved snapshot. So try to avoid phy_init() for USB
>>> +	 * except when gtr_phy->skip_phy_init is false (this happens when FPD is
>>> +	 * shutdown during suspend or when gt lane is changed from current one)
>>> +	 */
>>> +	if (gtr_phy->protocol == ICM_PROTOCOL_USB && gtr_phy->skip_phy_init)
>>> +		return false;
>>> +	else
>>
>> 'else' here is un-necessary.
> 
> Does it hurt though ? I find it more readable.
Fine then.
> 
>>> +		return true;
>>> +}
>>> +
>>> +/*
>>> + * There is a functional issue in the GT. The TX termination resistance can be
>>> + * out of spec due to a issue in the calibration logic. This is the workaround
>>> + * to fix it, required for XCZU9EG silicon.
>>> + */
>>> +static int xpsgtr_phy_tx_term_fix(struct xpsgtr_phy *gtr_phy)
>>> +{
>>> +	struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
>>> +	u32 timeout = TIMEOUT_US;
>>> +	u32 nsw;
>>> +
>>> +	/* Enabling Test Mode control for CMN Rest */
>>> +	xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_SET);
>>
>> This function writes to the global registers. Wouldn't this affect a lane that
>> is already configured?
> 
> This function is only executed once, for the first PHY that is
> initialized (see the caller, this is guarded with a mutex, so there's no
> race condition).

Indeed.

Thanks
Kishon

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