MLK-17416 imx8: sim: add usleep_range() before reading SPDP Bit

Card Presence Detect Status Bit SPDP in EMV_SIM_PCSR is
synchronized by two posedge of low_ref_clk which is 32KHz.

So there should be 1.5 low_ref_clk cycles(about 90us) before
reading SPDP Bit.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
(cherry pick from: 42a733a62525725d145ce6b55dfc94f1f5ff0a9d)
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>

diff --git a/drivers/mxc/sim/imx_emvsim.c b/drivers/mxc/sim/imx_emvsim.c
index ecb3451..ee8dde9 100644 (file)
--- a/drivers/mxc/sim/imx_emvsim.c
+++ b/drivers/mxc/sim/imx_emvsim.c
@@ -752,6 +752,7 @@ static void emvsim_start(struct emvsim_t *emvsim)
        clk_div = (clk_rate + emvsim->clk_rate - 1) / emvsim->clk_rate;
        __raw_writel(clk_div, emvsim->ioaddr + EMV_SIM_CLKCFG);
 
+       usleep_range(90, 100);
        /* SPDP=0: SIM Presence Detect pin is low, default PRESENT status */
        if (__raw_readl(emvsim->ioaddr + EMV_SIM_PCSR) & SPDP) {
                emvsim->present = SIM_PRESENT_REMOVED;