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path: root/drivers/spi/spi-rspi.c
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Diffstat (limited to 'drivers/spi/spi-rspi.c')
-rw-r--r--drivers/spi/spi-rspi.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 818843336932..a816f07e168e 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -295,14 +295,24 @@ static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
{
int spbr;
+ int div = 0;
+ unsigned long clksrc;
/* Sets output mode, MOSI signal, and (optionally) loopback */
rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
+ clksrc = clk_get_rate(rspi->clk);
+ while (div < 3) {
+ if (rspi->max_speed_hz >= clksrc/4) /* 4=(CLK/2)/2 */
+ break;
+ div++;
+ clksrc /= 2;
+ }
+
/* Sets transfer bit rate */
- spbr = DIV_ROUND_UP(clk_get_rate(rspi->clk),
- 2 * rspi->max_speed_hz) - 1;
+ spbr = DIV_ROUND_UP(clksrc, 2 * rspi->max_speed_hz) - 1;
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
+ rspi->spcmd |= div << 2;
/* Disable dummy transmission, set byte access */
rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);