From: Ulf Hansson <ulf.hansson@xxxxxxxxxxxxxx>
The Ux500 variant of this block has a different divider.
The value used right now is too big and which means a loss
in performance. This fix corrects it.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
drivers/mmc/host/mmci.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index cabd386..21fd486 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -57,6 +57,7 @@ static unsigned int fmax = 515633;
* @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when
* using DMA.
* @sdio: variant supports SDIO
+ * @st_clkdiv: true if using a ST-specific clock divider algorithm
*/
struct variant_data {
unsigned int clkreg;
@@ -69,6 +70,7 @@ struct variant_data {
bool broken_blockend;
bool broken_blockend_dma;
bool sdio;
+ bool st_clkdiv;
};
static struct variant_data variant_arm = {
@@ -96,7 +98,9 @@ static struct variant_data variant_ux500 = {
.datalength_bits = 24,
.broken_blockend = true,
.sdio = true,
+ .st_clkdiv = true,
};
+
/*
* This must be called with host->lock held
*/
@@ -109,6 +113,11 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
if (desired >= host->mclk) {
clk = MCI_CLK_BYPASS;
host->cclk = host->mclk;
+ } else if (variant->st_clkdiv) {
+ clk = ((host->mclk + desired - 1) / desired) - 2;
+ if (clk >= 256)
+ clk = 255;
+ host->cclk = host->mclk / (clk + 2);
} else {
clk = host->mclk / (2 * desired) - 1;
if (clk >= 256)
--
1.7.3.2
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