The PXA168 has a documented silicon bug that causes SDIO card IRQs to be
missed. Implement the first half of the suggested workaround, which
involves resetting the data port logic and issuing a dummy CMD0 to
restart the clock.
Signed-off-by: Doug Brown <doug@xxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav2.c | 36 ++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index 4996d72c6d23..0b9b2e4b2153 100644
--- a/drivers/mmc/host/sdhci-pxav2.c
+++ b/drivers/mmc/host/sdhci-pxav2.c
@@ -20,6 +20,8 @@
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/mmc/sdio.h>
+#include <linux/mmc/mmc.h>
#include "sdhci.h"
#include "sdhci-pltfm.h"
@@ -43,6 +45,7 @@
struct sdhci_pxav2_host {
struct clk *clk_core;
+ void (*orig_post_req)(struct mmc_host *mmc, struct mmc_request *mrq, int err);
};
static void pxav2_reset(struct sdhci_host *host, u8 mask)
@@ -96,6 +99,37 @@ static inline u16 pxav1_readw(struct sdhci_host *host, int reg)
return readw(host->ioaddr + reg);
}
+static void pxav1_post_req(struct mmc_host *mmc, struct mmc_request *mrq, int err)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_pxav2_host *pxav2_host;
+ struct mmc_command dummy_cmd = {};
+ u16 tmp;
+
+ /* If this is an SDIO command, perform errata workaround for silicon bug. */
+ if (!err && mrq->cmd && !mrq->cmd->error &&
+ (mrq->cmd->opcode == SD_IO_RW_DIRECT ||
+ mrq->cmd->opcode == SD_IO_RW_EXTENDED)) {
+ /* Reset data port */
+ tmp = readw(host->ioaddr + SDHCI_TIMEOUT_CONTROL);
+ tmp |= 0x400;
+ writew(tmp, host->ioaddr + SDHCI_TIMEOUT_CONTROL);
+
+ /* Clock is now stopped, so restart it by sending a dummy CMD0. */
+ pxav2_host = sdhci_pltfm_priv(sdhci_priv(host));
+
+ dummy_cmd.opcode = MMC_GO_IDLE_STATE;
+ dummy_cmd.arg = 0;
+ dummy_cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_NONE | MMC_CMD_BC;
+
+ mmc_wait_for_cmd(host->mmc, &dummy_cmd, 0);
+ }
+
+ /* Pass onto SDHCI host driver now */
+ if (pxav2_host->orig_post_req)
+ pxav2_host->orig_post_req(mmc, mrq, err);
+}
+
static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
{
u8 ctrl;
@@ -252,6 +286,8 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
if (match && of_device_is_compatible(dev->of_node, "mrvl,pxav1-mmc")) {
host->quirks |= SDHCI_QUIRK_NO_BUSY_IRQ | SDHCI_QUIRK_32BIT_DMA_SIZE;
host->ops = &pxav1_sdhci_ops;
+ pxav2_host->orig_post_req = host->mmc_host_ops.post_req;
+ host->mmc_host_ops.post_req = pxav1_post_req;
} else {
host->ops = &pxav2_sdhci_ops;
}
--
2.34.1
