Re: [PATCH] phy: xilinx: phy-zynqmp: Fix SGMII linkup failure on resume

[Vinod Koul <vkoul@kernel.org>]

On 17-07-24, 00:11, Radhey Shyam Pandey wrote:
> From: Piyush Mehta <piyush.mehta@amd.com>
> 
> On a few Kria KR260 Robotics Starter Kit the PS-GEM SGMII linkup is not
> happening after the resume. This is because serdes registers are reset
> when FPD is off (in suspend state) and needs to be reprogrammed in the
> resume path with the same default initialization as done in the first
> stage bootloader psu_init routine.
> 
> To address the failure introduce a set of serdes registers to be saved in
> the suspend path and then restore it on resume.
> 
> Signed-off-by: Piyush Mehta <piyush.mehta@amd.com>
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
> ---
>  drivers/phy/xilinx/phy-zynqmp.c | 56 +++++++++++++++++++++++++++++++++
>  1 file changed, 56 insertions(+)
> 
> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
> index dc8319bda43d..bdcc8d7c3dfa 100644
> --- a/drivers/phy/xilinx/phy-zynqmp.c
> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> @@ -165,6 +165,24 @@
>  /* Timeout values */
>  #define TIMEOUT_US			1000
>  
> +/* Lane 0/1/2/3 offset */
> +#define DIG_8(n)		((0x4000 * (n)) + 0x1074)
> +#define ILL13(n)		((0x4000 * (n)) + 0x1994)
> +#define DIG_10(n)		((0x4000 * (n)) + 0x107C)
> +#define RST_DLY(n)		((0x4000 * (n)) + 0x19A4)
> +#define BYP_15(n)		((0x4000 * (n)) + 0x1038)
> +#define BYP_12(n)		((0x4000 * (n)) + 0x102C)
> +#define MISC3(n)		((0x4000 * (n)) + 0x19AC)
> +#define EQ11(n)			((0x4000 * (n)) + 0x1978)

Lower case hex value please

> +
> +static u32 save_reg_address[] = {
> +	/* Lane 0/1/2/3 Register */
> +	DIG_8(0), ILL13(0), DIG_10(0), RST_DLY(0), BYP_15(0), BYP_12(0), MISC3(0), EQ11(0),
> +	DIG_8(1), ILL13(1), DIG_10(1), RST_DLY(1), BYP_15(1), BYP_12(1), MISC3(1), EQ11(1),
> +	DIG_8(2), ILL13(2), DIG_10(2), RST_DLY(2), BYP_15(2), BYP_12(2), MISC3(2), EQ11(2),
> +	DIG_8(3), ILL13(3), DIG_10(3), RST_DLY(3), BYP_15(3), BYP_12(3), MISC3(3), EQ11(3),
> +};
> +
>  struct xpsgtr_dev;
>  
>  /**
> @@ -213,6 +231,7 @@ struct xpsgtr_phy {
>   * @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
> + * @saved_regs: registers to be saved/restored during suspend/resume
>   */
>  struct xpsgtr_dev {
>  	struct device *dev;
> @@ -225,6 +244,7 @@ struct xpsgtr_dev {
>  	bool tx_term_fix;
>  	unsigned int saved_icm_cfg0;
>  	unsigned int saved_icm_cfg1;
> +	u32 *saved_regs;
>  };
>  
>  /*
> @@ -298,6 +318,32 @@ static inline void xpsgtr_clr_set_phy(struct xpsgtr_phy *gtr_phy,
>  	writel((readl(addr) & ~clr) | set, addr);
>  }
>  
> +/**
> + * xpsgtr_save_lane_regs - Saves registers on suspend
> + * @gtr_dev: pointer to phy controller context structure
> + */
> +static void xpsgtr_save_lane_regs(struct xpsgtr_dev *gtr_dev)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(save_reg_address); i++)
> +		gtr_dev->saved_regs[i] = xpsgtr_read(gtr_dev,
> +						     save_reg_address[i]);
> +}
> +
> +/**
> + * xpsgtr_restore_lane_regs - Restores registers on resume
> + * @gtr_dev: pointer to phy controller context structure
> + */
> +static void xpsgtr_restore_lane_regs(struct xpsgtr_dev *gtr_dev)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(save_reg_address); i++)
> +		xpsgtr_write(gtr_dev, save_reg_address[i],
> +			     gtr_dev->saved_regs[i]);
> +}
> +
>  /*
>   * Hardware Configuration
>   */
> @@ -837,6 +883,8 @@ static int xpsgtr_runtime_suspend(struct device *dev)
>  	gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
>  	gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
>  
> +	xpsgtr_save_lane_regs(gtr_dev);
> +
>  	return 0;
>  }
>  
> @@ -847,6 +895,8 @@ static int xpsgtr_runtime_resume(struct device *dev)
>  	unsigned int i;
>  	bool skip_phy_init;
>  
> +	xpsgtr_restore_lane_regs(gtr_dev);
> +
>  	icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
>  	icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
>  
> @@ -992,6 +1042,12 @@ static int xpsgtr_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> +	gtr_dev->saved_regs = devm_kmalloc(gtr_dev->dev,
> +					   sizeof(save_reg_address),
> +					   GFP_KERNEL);
> +	if (!gtr_dev->saved_regs)
> +		return -ENOMEM;
> +
>  	return 0;
>  }
>  
> 
> base-commit: d67978318827d06f1c0fa4c31343a279e9df6fde
> -- 
> 2.34.1

-- 
~Vinod

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