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-rw-r--r--drivers/spi/mxc_spi.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index dadf228..2a4ddad 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -199,15 +199,36 @@ void spi_cs_deactivate(struct spi_slave *slave)
!(mxcs->ss_pol));
}
+u32 get_cspi_div(u32 div)
+{
+ int i;
+
+ for (i = 0; i < 8; i++) {
+ if (div <= (4 << i))
+ return i;
+ }
+ return i;
+}
+
#if defined(CONFIG_MX31) || defined(CONFIG_MX35)
static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
unsigned int ctrl_reg;
+ u32 clk_src;
+ u32 div;
+
+ clk_src = mxc_get_clock(MXC_CSPI_CLK);
+
+ div = clk_src / max_hz;
+ div = get_cspi_div(div);
+
+ debug("clk %d Hz, div %d, real clk %d Hz\n",
+ max_hz, div, clk_src / (4 << div));
ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) |
MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS) |
- MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */
+ MXC_CSPICTRL_DATARATE(div) |
MXC_CSPICTRL_EN |
#ifdef CONFIG_MX35
MXC_CSPICTRL_SSCTL |