The PXA168 has a documented silicon bug that results in a data abort
exception when accessing the SDHCI_HOST_VERSION register on SDH2 and
SDH4 through a 16-bit read. Implement the workaround described in the
errata, which performs a 32-bit read from a lower address instead. This
is safe to use on all four SDH peripherals.
Signed-off-by: Doug Brown <doug@xxxxxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci-pxav2.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c
index 5707d597ecae..5e01dab94426 100644
--- a/drivers/mmc/host/sdhci-pxav2.c
+++ b/drivers/mmc/host/sdhci-pxav2.c
@@ -80,6 +80,15 @@ static void pxav2_reset(struct sdhci_host *host, u8 mask)
}
}
+static u16 pxav1_readw(struct sdhci_host *host, int reg)
+{
+ /* Workaround for data abort exception on SDH2 and SDH4 on PXA168 */
+ if (reg == SDHCI_HOST_VERSION)
+ return readl(host->ioaddr + SDHCI_HOST_VERSION - 2) >> 16;
+
+ return readw(host->ioaddr + reg);
+}
+
static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
{
u8 ctrl;
@@ -107,6 +116,7 @@ struct sdhci_pxa_variant {
};
static const struct sdhci_ops pxav1_sdhci_ops = {
+ .read_w = pxav1_readw,
.set_clock = sdhci_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = pxav2_mmc_set_bus_width,
--
2.34.1
