diff options
Diffstat (limited to 'drivers/spi/spi-rspi.c')
| -rw-r--r-- | drivers/spi/spi-rspi.c | 14 |
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); |