The PXA168 errata recommends that the CMD signal should be detached from
the SD bus while performing the dummy CMD0 to restart the clock.
Implement this using pinctrl states.
Signed-off-by: Doug Brown <doug@xxxxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav2.c | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index 3dafffaa0c6e..fc306eb1f845 100644
--- a/drivers/mmc/host/sdhci-pxav2.c
+++ b/drivers/mmc/host/sdhci-pxav2.c
@@ -22,6 +22,7 @@
#include <linux/of_device.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/mmc.h>
+#include <linux/pinctrl/consumer.h>
#include "sdhci.h"
#include "sdhci-pltfm.h"
@@ -45,6 +46,9 @@
struct sdhci_pxav2_host {
struct mmc_request *sdio_mrq;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *pins_default;
+ struct pinctrl_state *pins_cmd_gpio;
};
static void pxav2_reset(struct sdhci_host *host, u8 mask)
@@ -104,6 +108,11 @@ static u32 pxav1_irq(struct sdhci_host *host, u32 intmask)
/* The dummy CMD0 for the SDIO workaround just completed */
sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK, SDHCI_INT_STATUS);
intmask &= ~SDHCI_INT_CMD_MASK;
+
+ /* Restore MMC function to CMD pin */
+ if (pxav2_host->pinctrl && pxav2_host->pins_default)
+ pinctrl_select_state(pxav2_host->pinctrl, pxav2_host->pins_default);
+
sdio_mrq = pxav2_host->sdio_mrq;
pxav2_host->sdio_mrq = NULL;
mmc_request_done(host->mmc, sdio_mrq);
@@ -129,6 +138,11 @@ static void pxav1_request_done(struct sdhci_host *host, struct mmc_request *mrq)
/* Clock is now stopped, so restart it by sending a dummy CMD0 */
pxav2_host = sdhci_pltfm_priv(sdhci_priv(host));
pxav2_host->sdio_mrq = mrq;
+
+ /* Set CMD as high output rather than MMC function while we do CMD0 */
+ if (pxav2_host->pinctrl && pxav2_host->pins_cmd_gpio)
+ pinctrl_select_state(pxav2_host->pinctrl, pxav2_host->pins_cmd_gpio);
+
sdhci_writel(host, 0, SDHCI_ARGUMENT);
sdhci_writew(host, 0, SDHCI_TRANSFER_MODE);
sdhci_writew(host, SDHCI_MAKE_CMD(MMC_GO_IDLE_STATE, SDHCI_CMD_RESP_NONE),
@@ -240,6 +254,7 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
{
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_pxa_platdata *pdata = pdev->dev.platform_data;
+ struct sdhci_pxav2_host *pxav2_host;
struct device *dev = &pdev->dev;
struct sdhci_host *host = NULL;
const struct sdhci_pxa_variant *variant;
@@ -247,11 +262,12 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
int ret;
struct clk *clk, *clk_core;
- host = sdhci_pltfm_init(pdev, NULL, sizeof(struct sdhci_pxav2_host));
+ host = sdhci_pltfm_init(pdev, NULL, sizeof(*pxav2_host));
if (IS_ERR(host))
return PTR_ERR(host);
pltfm_host = sdhci_priv(host);
+ pxav2_host = sdhci_pltfm_priv(pltfm_host);
clk = devm_clk_get(dev, "io");
if (IS_ERR(clk) && PTR_ERR(clk) != -EPROBE_DEFER)
@@ -307,6 +323,21 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
host->quirks |= variant->extra_quirks;
host->ops = variant->ops;
+ /* Set up optional pinctrl for PXA168 SDIO IRQ fix */
+ pxav2_host->pinctrl = devm_pinctrl_get(dev);
+ if (!IS_ERR(pxav2_host->pinctrl)) {
+ pxav2_host->pins_cmd_gpio = pinctrl_lookup_state(pxav2_host->pinctrl,
+ "state_cmd_gpio");
+ if (IS_ERR(pxav2_host->pins_cmd_gpio))
+ pxav2_host->pins_cmd_gpio = NULL;
+ pxav2_host->pins_default = pinctrl_lookup_state(pxav2_host->pinctrl,
+ "default");
+ if (IS_ERR(pxav2_host->pins_default))
+ pxav2_host->pins_default = NULL;
+ } else {
+ pxav2_host->pinctrl = NULL;
+ }
+
ret = sdhci_add_host(host);
if (ret)
goto disable_clk;
--
2.34.1
