Subject: Re: [RESEND v6 07/13] spi: imx: remove ERR009165 workaround on i.mx6ul

From: Sascha Hauer <[email-masked]>
Date: Tue, 10 Mar 2020 09:02:41 +0100

On Tue, Mar 10, 2020 at 07:31:56PM +0800, Robin Gong wrote:
> ERR009165 fixed on i.mx6ul/6ull/6sll. All other i.mx6/7 and
> i.mx8m/8mm still need this errata. Please refer to nxp official
> errata document from https://www.nxp.com/ .
> 
> For removing workaround on those chips. Add new i.mx6ul type.
> 
> Signed-off-by: Robin Gong <[email-masked]>
> Acked-by: Mark Brown <[email-masked]>
> ---
>  drivers/spi/spi-imx.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 45 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
> index 842a86e..f7ee2ec 100644
> --- a/drivers/spi/spi-imx.c
> +++ b/drivers/spi/spi-imx.c
> @@ -57,6 +57,7 @@ enum spi_imx_devtype {
>  	IMX35_CSPI,	/* CSPI on all i.mx except above */
>  	IMX51_ECSPI,	/* ECSPI on i.mx51 */
>  	IMX53_ECSPI,	/* ECSPI on i.mx53 and later */
> +	IMX6UL_ECSPI,	/* ERR009165 fix from i.mx6ul */
>  };
>  
>  struct spi_imx_data;
> @@ -75,6 +76,11 @@ struct spi_imx_devtype_data {
>  	bool has_slavemode;
>  	unsigned int fifo_size;
>  	bool dynamic_burst;
> +	/*
> +	 * ERR009165 fixed or not:
> +	 * https://www.nxp.com/docs/en/errata/IMX6DQCE.pdf
> +	 */
> +	bool tx_glitch_fixed;
>  	enum spi_imx_devtype devtype;
>  };
>  
> @@ -128,7 +134,8 @@ static inline int is_imx35_cspi(struct spi_imx_data *d)
>  
>  static inline int is_imx51_ecspi(struct spi_imx_data *d)
>  {
> -	return d->devtype_data->devtype == IMX51_ECSPI;
> +	return d->devtype_data->devtype == IMX51_ECSPI ||
> +	       d->devtype_data->devtype == IMX6UL_ECSPI;
>  }

Erm, no. A i.MX51 ECSPI is a i.MX51 ECSPI and not a i.MX6UL ECSPI. If
you want to handle them equally somewhere then explicitly test for
i.MX6ul *and* i.MX51 there.

>  
>  static inline int is_imx53_ecspi(struct spi_imx_data *d)
> @@ -585,9 +592,16 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
>  	ctrl |= mx51_ecspi_clkdiv(spi_imx, t->speed_hz, &clk);
>  	spi_imx->spi_bus_clk = clk;
>  
> -	/* ERR009165: work in XHC mode as PIO */
> -	if (spi_imx->usedma)
> -		ctrl &= ~MX51_ECSPI_CTRL_SMC;
> +	/*
> +	 * ERR009165: work in XHC mode instead of SMC as PIO on the chips
> +	 * before i.mx6ul.
> +	 */
> +	if (spi_imx->usedma) {
> +		if (spi_imx->devtype_data->tx_glitch_fixed)
> +			ctrl |= MX51_ECSPI_CTRL_SMC;
> +		else
> +			ctrl &= ~MX51_ECSPI_CTRL_SMC;
> +	}

Changed again, but the PIO case still not honoured. This should look
like
	if (spi_imx->usedma && spi_imx->devtype_data->tx_glitch_fixed)
		ctrl |= MX51_ECSPI_CTRL_SMC;
	else
		ctrl &= ~MX51_ECSPI_CTRL_SMC;

>  
>  	writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
>  
> @@ -615,6 +629,8 @@ static void mx51_setup_wml(struct spi_imx_data *spi_imx)
>  {
>  	u32 tx_wml = 0;
>  
> +	if (spi_imx->devtype_data->tx_glitch_fixed)
> +		tx_wml = spi_imx->wml;

That explains the variable introduced in the last patch, ok.

I have the impression that splitting up 06/13 and 07/13 into two patches
doesn't make it easier to review.

Sascha

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