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path: root/drivers/mmc/host/renesas_sdhi_internal_dmac.c
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Diffstat (limited to 'drivers/mmc/host/renesas_sdhi_internal_dmac.c')
-rw-r--r--drivers/mmc/host/renesas_sdhi_internal_dmac.c39
1 files changed, 33 insertions, 6 deletions
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index 8e0acd197c43..6af946d16d24 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -9,6 +9,7 @@
* published by the Free Software Foundation.
*/
+#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/io-64-nonatomic-hi-lo.h>
@@ -62,6 +63,17 @@
* need a custom accessor.
*/
+static unsigned long global_flags;
+/*
+ * Workaround for avoiding to use RX DMAC by multiple channels.
+ * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
+ * RX DMAC simultaneously, sometimes hundreds of bytes data are not
+ * stored into the system memory even if the DMAC interrupt happened.
+ * So, this driver then uses one RX DMAC channel only.
+ */
+#define SDHI_INTERNAL_DMAC_ONE_RX_ONLY 0
+#define SDHI_INTERNAL_DMAC_RX_IN_USE 1
+
/* Definitions for sampling clocks */
static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
{
@@ -126,6 +138,9 @@ renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
RST_RESERVED_BITS | val);
+ if (host->data && host->data->flags & MMC_DATA_READ)
+ clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
+
renesas_sdhi_internal_dmac_enable_dma(host, true);
}
@@ -155,6 +170,9 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
if (data->flags & MMC_DATA_READ) {
dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
dir = DMA_FROM_DEVICE;
+ if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
+ test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
+ goto force_pio;
} else {
dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
dir = DMA_TO_DEVICE;
@@ -208,6 +226,9 @@ static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
renesas_sdhi_internal_dmac_enable_dma(host, false);
dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);
+ if (dir == DMA_FROM_DEVICE)
+ clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
+
tmio_mmc_do_data_irq(host);
out:
spin_unlock_irq(&host->lock);
@@ -251,18 +272,24 @@ static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
* implementation as others may use a different implementation.
*/
static const struct soc_device_attribute gen3_soc_whitelist[] = {
- { .soc_id = "r8a7795", .revision = "ES1.*" },
- { .soc_id = "r8a7795", .revision = "ES2.0" },
- { .soc_id = "r8a7796", .revision = "ES1.0" },
- { .soc_id = "r8a77995", .revision = "ES1.0" },
- { /* sentinel */ }
+ { .soc_id = "r8a7795", .revision = "ES1.*",
+ .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
+ { .soc_id = "r8a7795", .revision = "ES2.0" },
+ { .soc_id = "r8a7796", .revision = "ES1.0",
+ .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
+ { .soc_id = "r8a77995", .revision = "ES1.0" },
+ { /* sentinel */ }
};
static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
{
- if (!soc_device_match(gen3_soc_whitelist))
+ const struct soc_device_attribute *soc = soc_device_match(gen3_soc_whitelist);
+
+ if (!soc)
return -ENODEV;
+ global_flags |= (unsigned long)soc->data;
+
return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
}