[PATCH v4 03/12] mmc: sdhci-omap: Workaround for Errata i843

From: Kishon Vijay Abraham I
Date: Wed Apr 25 2018 - 08:13:34 EST


Errata i843 in AM572x Sitara Processors Silicon Revision 2.0, 1.1
(SPRZ429L July 2014âRevised April 2018 [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/sprz429l/sprz429l.pdf

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
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 6e2cf4cfeec0..b4400be0606f 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);
--
2.17.0