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>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav2.c | 56 +++++++++++++++++++++++++++++++++-
1 file changed, 55 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index b10f55b478fc..10fa9de14ad4 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"
@@ -41,6 +43,10 @@
#define MMC_CARD 0x1000
#define MMC_WIDTH 0x0100
+struct sdhci_pxav2_host {
+ struct mmc_request *sdio_mrq;
+};
+
static void pxav2_reset(struct sdhci_host *host, u8 mask)
{
struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
@@ -89,6 +95,52 @@ 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));
+ struct mmc_request *sdio_mrq;
+
+ 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;
+ sdio_mrq = pxav2_host->sdio_mrq;
+ pxav2_host->sdio_mrq = NULL;
+ mmc_request_done(host->mmc, sdio_mrq);
+ }
+
+ 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;
@@ -118,10 +170,12 @@ struct sdhci_pxa_variant {
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_pxa_variant __maybe_unused pxav1_variant = {
@@ -193,7 +247,7 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
int ret;
struct clk *clk, *clk_core;
- host = sdhci_pltfm_init(pdev, NULL, 0);
+ host = sdhci_pltfm_init(pdev, NULL, sizeof(struct sdhci_pxav2_host));
if (IS_ERR(host))
return PTR_ERR(host);
--
2.34.1
