Re: [PATCH v3 03/11] mmc: sdhci-omap: Workaround for Errata i843

[Adrian Hunter]

On 07/03/18 15:20, Kishon Vijay Abraham I wrote:
> Errata i843 in AM572x Sitara Processors Silicon Revision 2.0, 1.1
> (SPRZ429K July 2014âRevised March 2017 [1]) mentions
> PG 1.0/1.1 silicon has limitations w.r.t frequencies at which MMC1/2/3
> can operate.
> 
> Use soc_device_match() to identify rev 1.0/1.1 silicon and
> override mmc->f_max according to the errata workaround.
> "max-frequency" dt property cannot be used since the device
> tree is added for rev 2.0 silicon.
> 
> soc_device_match() is also used in order to get the IODelay values
> for rev 1.0/1.1 silicon.
> 
> [1] -> http://www.ti.com/lit/er/sprz429k/sprz429k.pdf
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
>  drivers/mmc/host/sdhci-omap.c | 35 ++++++++++++++++++++++++++++++++++-
>  1 file changed, 34 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
> index 0c40b13fb67d..fbc20a4fbb23 100644
> --- a/drivers/mmc/host/sdhci-omap.c
> +++ b/drivers/mmc/host/sdhci-omap.c
> @@ -26,6 +26,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/pinctrl/consumer.h>
> +#include <linux/sys_soc.h>
>  
>  #include "sdhci-pltfm.h"
>  
> @@ -100,6 +101,7 @@ struct sdhci_omap_data {
>  };
>  
>  struct sdhci_omap_host {
> +	char			*version;
>  	void __iomem		*base;
>  	struct device		*dev;
>  	struct	regulator	*pbias;
> @@ -733,12 +735,21 @@ static struct pinctrl_state
>  				  u32 *caps, u32 capmask)
>  {
>  	struct device *dev = omap_host->dev;
> +	char *version = omap_host->version;
>  	struct pinctrl_state *pinctrl_state = ERR_PTR(-ENODEV);
> +	char str[20];
>  
>  	if (!(*caps & capmask))
>  		goto ret;
>  
> -	pinctrl_state = pinctrl_lookup_state(omap_host->pinctrl, mode);
> +	if (version) {
> +		snprintf(str, 20, "%s-%s", mode, version);
> +		pinctrl_state = pinctrl_lookup_state(omap_host->pinctrl, str);
> +	}
> +
> +	if (IS_ERR(pinctrl_state))
> +		pinctrl_state = pinctrl_lookup_state(omap_host->pinctrl, mode);
> +
>  	if (IS_ERR(pinctrl_state)) {
>  		dev_err(dev, "no pinctrl state for %s mode", mode);
>  		*caps &= ~capmask;
> @@ -830,6 +841,16 @@ static int sdhci_omap_config_iodelay_pinctrl_state(struct sdhci_omap_host
>  	return 0;
>  }
>  
> +static const struct soc_device_attribute sdhci_omap_soc_devices[] = {
> +	{
> +		.machine = "DRA7[45]*",
> +		.revision = "ES1.[01]",
> +	},
> +	{
> +		/* sentinel */
> +	}
> +};
> +
>  static int sdhci_omap_probe(struct platform_device *pdev)
>  {
>  	int ret;
> @@ -841,6 +862,7 @@ static int sdhci_omap_probe(struct platform_device *pdev)
>  	struct mmc_host *mmc;
>  	const struct of_device_id *match;
>  	struct sdhci_omap_data *data;
> +	const struct soc_device_attribute *soc;
>  
>  	match = of_match_device(omap_sdhci_match, dev);
>  	if (!match)
> @@ -875,6 +897,17 @@ static int sdhci_omap_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto err_pltfm_free;
>  
> +	soc = soc_device_match(sdhci_omap_soc_devices);
> +	if (soc) {
> +		omap_host->version = "rev11";
> +		if (!strcmp(dev_name(dev), "4809c000.mmc"))
> +			mmc->f_max = 96000000;
> +		if (!strcmp(dev_name(dev), "480b4000.mmc"))
> +			mmc->f_max = 48000000;
> +		if (!strcmp(dev_name(dev), "480ad000.mmc"))
> +			mmc->f_max = 48000000;
> +	}
> +
>  	pltfm_host->clk = devm_clk_get(dev, "fck");
>  	if (IS_ERR(pltfm_host->clk)) {
>  		ret = PTR_ERR(pltfm_host->clk);
>