Re: [PATCH 4/4] mci: dwcmshc-sdhci: add support for Kalray Coolidge v2 SoC eMMC controller

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Hello Yann,

On 29.02.24 16:57, Yann Sionneau wrote:
> Kalray Coolidge v2 SoC eMMC controller needs static tx delay tuning even
> for basic standard or high speed modes.
> 
> This patch also adds possibility to do some vendor specific tuning
> in set_ios().
> This will be needed for Coolidge v2 for >50 MHz speeds and HS200/HS400
> modes.
> 
> Signed-off-by: Yann Sionneau <ysionneau@kalrayinc.com>
> ---
>  drivers/mci/dwcmshc-sdhci.c | 40 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/drivers/mci/dwcmshc-sdhci.c b/drivers/mci/dwcmshc-sdhci.c
> index d9c51752db..5017a1f56e 100644
> --- a/drivers/mci/dwcmshc-sdhci.c
> +++ b/drivers/mci/dwcmshc-sdhci.c
> @@ -9,11 +9,16 @@
>  #include <dma.h>
>  #include <malloc.h>
>  #include <mci.h>
> +#include <of_device.h>
>  #include <linux/err.h>
>  #include <linux/clk.h>
>  
>  #include "sdhci.h"
>  
> +#define tx_delay_static_cfg(delay)      (delay << 5)
> +#define tx_tuning_clk_sel(delay)        (delay)
> +
> +#define DWCMSHC_GPIO_OUT  0x34 /* offset from vendor specific area */
>  #define CARD_STATUS_MASK (0x1e00)
>  #define CARD_STATUS_TRAN (4 << 9)
>  
> @@ -22,6 +27,13 @@ static int do_send_cmd(struct mci_host *mci, struct mci_cmd *cmd, struct mci_dat
>  struct dwcmshc_host {
>  	struct mci_host mci;
>  	struct sdhci sdhci;
> +	int vendor_specific_area;
> +	const struct dwcmshc_callbacks *cb;
> +};
> +
> +struct dwcmshc_callbacks {
> +	void (*init)(struct mci_host *mci, struct device *dev);

Why is dev needed? There's already mci->hw_dev and mci->mci->dev

> +	void (*set_ios)(struct mci_host *mci, struct mci_ios *ios);

You don't actually use set_ios. But I assume you intend to add in future?
Maybe add it when it's actually needed?

> +static void dwcmshc_coolidgev2_init(struct mci_host *mci, struct device *dev)
> +{
> +	struct dwcmshc_host *host = priv_from_mci_host(mci);
> +
> +	// configure TX delay to set correct setup/hold for Coolidge V2

Nite: If you are going to send v2, please change into /* */ comments
for uniformity.


Cheers,
Ahmad

> +	sdhci_write32(&host->sdhci,
> +		      host->vendor_specific_area + DWCMSHC_GPIO_OUT,
> +		      tx_delay_static_cfg(0xf) | tx_tuning_clk_sel(4));
> +}
> +
> +struct dwcmshc_callbacks kalray_coolidgev2_callbacks = {
> +	.init = dwcmshc_coolidgev2_init,
> +};
> +
>  static struct of_device_id dwcmshc_dt_ids[] = {
>  	{ .compatible = "snps,dwcmshc-sdhci", },
> +	{ .compatible = "kalray,coolidge-v2-dwcmshc-sdhci", .data = &kalray_coolidgev2_callbacks },
>  	{ }
>  };
>  

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