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

From: Adrian Hunter
Date: Thu Mar 15 2018 - 10:25:54 EST


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);
>