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 | 49 ++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index 1f0c3028987a..912b2aad9f2e 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;
+ struct mmc_request *sdio_mrq;
};
static void pxav2_reset(struct sdhci_host *host, u8 mask)
@@ -93,6 +96,50 @@ static u16 pxav1_readw(struct sdhci_host *host, int reg)
return readw(host->ioaddr + reg);
}
+static u32 pxav1_irq(struct sdhci_host *host, u32 intmask)
+{
+ struct sdhci_pxav2_host *pxav2_host = sdhci_pltfm_priv(sdhci_priv(host));
+
+ if (pxav2_host->sdio_mrq && (intmask & SDHCI_INT_CMD_MASK)) {
+ /* 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;
+ mmc_request_done(host->mmc, pxav2_host->sdio_mrq);
+ pxav2_host->sdio_mrq = NULL;
+ }
+
+ return intmask;
+}
+
+static void pxav1_request_done(struct sdhci_host *host, struct mmc_request *mrq)
+{
+ u16 tmp;
+ struct sdhci_pxav2_host *pxav2_host;
+
+ /* If this is an SDIO command, perform errata workaround for silicon bug */
+ if (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));
+ pxav2_host->sdio_mrq = mrq;
+ 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),
+ SDHCI_COMMAND);
+
+ /* Don't finish this request until the dummy CMD0 finishes */
+ return;
+ }
+
+ mmc_request_done(host->mmc, mrq);
+}
+
static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
{
u8 ctrl;
@@ -117,10 +164,12 @@ static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
static const struct sdhci_ops pxav1_sdhci_ops = {
.read_w = pxav1_readw,
.set_clock = sdhci_set_clock,
+ .irq = pxav1_irq,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = pxav2_mmc_set_bus_width,
.reset = pxav2_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
+ .request_done = pxav1_request_done,
};
static const struct sdhci_ops pxav2_sdhci_ops = {
--
2.34.1
