NFC: trf7970a: Disable SYS_CLK Output

Currently, support for providing the external
SYS_CLK signal on pin 27 is not supported so
turn it off by writing to the 'Modulator and
SYS_CLK Control' register immediately after
reset.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/nfc/trf7970a.c b/drivers/nfc/trf7970a.c
index 4709bea..9c0549d 100644 (file)
--- a/drivers/nfc/trf7970a.c
+++ b/drivers/nfc/trf7970a.c
@@ -775,6 +775,12 @@ static int trf7970a_init(struct trf7970a *trf)
        if (ret)
                goto err_out;
 
+       ret = trf7970a_write(trf, TRF7970A_MODULATOR_SYS_CLK_CTRL, 0);
+       if (ret)
+               goto err_out;
+
+       trf->modulator_sys_clk_ctrl = 0;
+
        /* Must clear NFC Target Detection Level reg due to erratum */
        ret = trf7970a_write(trf, TRF7970A_NFC_TARGET_LEVEL, 0);
        if (ret)