bus: ti-sysc: Improve reset to work with modules with no sysconfig

At least display susbsystem (DSS) has modules with no sysconfig registers
and rely on custom function for module reset handling. Let's make reset
work with that too.

Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
index 31dae22..f32ba6e 100644 (file)
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -1571,7 +1571,7 @@ static int sysc_reset(struct sysc *ddata)
        sysc_offset = ddata->offsets[SYSC_SYSCONFIG];
        syss_offset = ddata->offsets[SYSC_SYSSTATUS];
 
-       if (ddata->legacy_mode || sysc_offset < 0 ||
+       if (ddata->legacy_mode ||
            ddata->cap->regbits->srst_shift < 0 ||
            ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)
                return 0;
@@ -1586,9 +1586,11 @@ static int sysc_reset(struct sysc *ddata)
        if (ddata->pre_reset_quirk)
                ddata->pre_reset_quirk(ddata);
 
-       sysc_val = sysc_read_sysconfig(ddata);
-       sysc_val |= sysc_mask;
-       sysc_write(ddata, sysc_offset, sysc_val);
+       if (sysc_offset >= 0) {
+               sysc_val = sysc_read_sysconfig(ddata);
+               sysc_val |= sysc_mask;
+               sysc_write(ddata, sysc_offset, sysc_val);
+       }
 
        if (ddata->cfg.srst_udelay)
                usleep_range(ddata->cfg.srst_udelay,