mfd: rtsx: Add clock divider hook

Add callback function conv_clk_and_div_n to convert between SSC clock
and its divider N.
For rtl8411, the formula to calculate SSC clock divider N is different
with the other card reader models.

Signed-off-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/mfd/rtl8411.c b/drivers/mfd/rtl8411.c
index 5058ba8dec3b..3d3b4addf81a 100644
--- a/drivers/mfd/rtl8411.c
+++ b/drivers/mfd/rtl8411.c
@@ -178,6 +178,18 @@ static unsigned int rtl8411_cd_deglitch(struct rtsx_pcr *pcr)
         return card_exist;
 }
 
+static int rtl8411_conv_clk_and_div_n(int input, int dir)
+{
+        int output;
+
+        if (dir == CLK_TO_DIV_N)
+                output = input * 4 / 5 - 2;
+        else
+                output = (input + 2) * 5 / 4;
+
+        return output;
+}
+
 static const struct pcr_ops rtl8411_pcr_ops = {
         .extra_init_hw = rtl8411_extra_init_hw,
         .optimize_phy = NULL,
@@ -189,6 +201,7 @@ static const struct pcr_ops rtl8411_pcr_ops = {
         .card_power_off = rtl8411_card_power_off,
         .switch_output_voltage = rtl8411_switch_output_voltage,
         .cd_deglitch = rtl8411_cd_deglitch,
+        .conv_clk_and_div_n = rtl8411_conv_clk_and_div_n,
 };
 
 /* SD Pull Control Enable: