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Date:   Mon, 26 Dec 2022 13:56:29 +0800
From:   Xu Yilun <yilun.xu@intel.com>
To:     Nava kishore Manne <nava.kishore.manne@amd.com>
Cc:     michal.simek@xilinx.com, mdf@kernel.org, hao.wu@intel.com,
        trix@redhat.com, ronak.jain@xilinx.com, gregkh@linuxfoundation.org,
        tanmay.shah@xilinx.com, ben.levinsky@amd.com,
        harsha.harsha@xilinx.com, rajan.vaja@xilinx.com,
        mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org
Subject: Re: [PATCH v4 1/2] firmware: xilinx: Add pm api function for PL
 config reg readback
Message-ID: <Y6k3jXv+J7C43akc@yilunxu-OptiPlex-7050>
References: <20221223115850.2572573-1-nava.kishore.manne@amd.com>
 <20221223115850.2572573-2-nava.kishore.manne@amd.com>
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On 2022-12-23 at 17:28:49 +0530, Nava kishore Manne wrote:
> Adds PM API for performing Programmable Logic(PL) configuration
> register readback. It provides an interface to the firmware(pmufw)
> to readback the FPGA configuration register.
> 
> Signed-off-by: Nava kishore Manne <nava.kishore.manne@amd.com>
> ---
> changes for v2:
>               - None.
> 
> Changes for v3:
>               - Updated API and config reg read-back handling logic
>               - Updated the commit msg to align with the changes.
> 
> Changes for v4:
>               - Fix some minor coding issues. No functional changes.
>               - Updated Return value comments as suggested by Xu Yilun.
> 
>  drivers/firmware/xilinx/zynqmp.c     | 33 ++++++++++++++++++++++++++++
>  include/linux/firmware/xlnx-zynqmp.h | 10 +++++++++
>  2 files changed, 43 insertions(+)
> 
> diff --git a/drivers/firmware/xilinx/zynqmp.c b/drivers/firmware/xilinx/zynqmp.c
> index ff5cabe70a2b..ca954e1119b5 100644
> --- a/drivers/firmware/xilinx/zynqmp.c
> +++ b/drivers/firmware/xilinx/zynqmp.c
> @@ -941,6 +941,39 @@ int zynqmp_pm_fpga_get_status(u32 *value)
>  }
>  EXPORT_SYMBOL_GPL(zynqmp_pm_fpga_get_status);
>  
> +/**
> + * zynqmp_pm_fpga_get_config_status - Get the FPGA configuration status.
> + * @value: Buffer to store FPGA configuration status.
> + *
> + * This function provides access to the pmufw to get the FPGA configuration
> + * status
> + *
> + * Return: 0 on success, a negative value on error
> + */
> +int zynqmp_pm_fpga_get_config_status(u32 *value)
> +{
> +	u32 buf, phys_lower_addr, phys_upper_addr;

Why naming them phys_xxx?

> +	u32 ret_payload[PAYLOAD_ARG_CNT];
> +	int ret;
> +
> +	if (!value)
> +		return -EINVAL;
> +
> +	phys_lower_addr = lower_32_bits((u64)&buf);
> +	phys_upper_addr = upper_32_bits((u64)&buf);
> +
> +	ret = zynqmp_pm_invoke_fn(PM_FPGA_READ,
> +				  XILINX_ZYNQMP_PM_FPGA_CONFIG_STAT_OFFSET,
> +				  phys_lower_addr, phys_upper_addr,
> +				  XILINX_ZYNQMP_PM_FPGA_READ_CONFIG_REG,
> +				  ret_payload);
> +
> +	*value = ret_payload[1];
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(zynqmp_pm_fpga_get_config_status);
> +
>  /**
>   * zynqmp_pm_pinctrl_request - Request Pin from firmware
>   * @pin: Pin number to request
> diff --git a/include/linux/firmware/xlnx-zynqmp.h b/include/linux/firmware/xlnx-zynqmp.h
> index 76d2b3ebad84..29e8964f4297 100644
> --- a/include/linux/firmware/xlnx-zynqmp.h
> +++ b/include/linux/firmware/xlnx-zynqmp.h
> @@ -70,6 +70,10 @@
>  #define XILINX_ZYNQMP_PM_FPGA_FULL	0x0U
>  #define XILINX_ZYNQMP_PM_FPGA_PARTIAL	BIT(0)
>  
> +/* FPGA Status Reg */
> +#define XILINX_ZYNQMP_PM_FPGA_CONFIG_STAT_OFFSET	7U
> +#define XILINX_ZYNQMP_PM_FPGA_READ_CONFIG_REG		0U
> +
>  /*
>   * Node IDs for the Error Events.
>   */
> @@ -117,6 +121,7 @@ enum pm_api_id {
>  	PM_CLOCK_GETRATE = 42,
>  	PM_CLOCK_SETPARENT = 43,
>  	PM_CLOCK_GETPARENT = 44,
> +	PM_FPGA_READ = 46,
>  	PM_SECURE_AES = 47,
>  	PM_FEATURE_CHECK = 63,
>  };
> @@ -505,6 +510,7 @@ int zynqmp_pm_register_sgi(u32 sgi_num, u32 reset);
>  int zynqmp_pm_set_sd_config(u32 node, enum pm_sd_config_type config, u32 value);
>  int zynqmp_pm_set_gem_config(u32 node, enum pm_gem_config_type config,
>  			     u32 value);
> +int zynqmp_pm_fpga_get_config_status(u32 *value);

Is it better put it along with zynqmp_pm_fpga_get_status()?

Thanks,
Yilun

>  #else
>  static inline int zynqmp_pm_get_api_version(u32 *version)
>  {
> @@ -790,6 +796,10 @@ static inline int zynqmp_pm_set_gem_config(u32 node,
>  	return -ENODEV;
>  }
>  
> +static inline int zynqmp_pm_fpga_get_config_status(u32 *value)
> +{
> +	return -ENODEV;
> +}
>  #endif
>  
>  #endif /* __FIRMWARE_ZYNQMP_H__ */
> -- 
> 2.25.1
>