| Message ID | 1415360068-8606-1-git-send-email-andy.yan@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2014?11?07? 19:45, Lucas Stach wrote: > Am Freitag, den 07.11.2014, 19:35 +0800 schrieb Andy Yan: >> On rockchip rk3288, only word(32-bit) accesses are >> permitted for hdmi registers. Byte width access (writeb, >> readb) generates an imprecise external abort. >> >> Signed-off-by: Andy Yan <andy.yan@rock-chips.com> >> --- >> drivers/gpu/drm/bridge/dw_hdmi.c | 49 +++++++++++++++++++++++++++++++++++++--- >> 1 file changed, 46 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c >> index df76a8c..9867642 100644 >> --- a/drivers/gpu/drm/bridge/dw_hdmi.c >> +++ b/drivers/gpu/drm/bridge/dw_hdmi.c >> @@ -126,19 +126,42 @@ struct dw_hdmi { > [...] >> + u32 val; >> + >> + if (!of_property_read_u32(np, "reg-io-width", &val)) { >> + switch (val) { >> + case 4: >> + hdmi->write = dw_hdmi_writel; >> + hdmi->read = dw_hdmi_readl; >> + hdmi->reg_shift = 2; >> + break; >> + default: >> + hdmi->write = dw_hdmi_writeb; >> + hdmi->read = dw_hdmi_readb; >> + hdmi->reg_shift = 0; >> + break; >> + } >> + } else { >> + hdmi->write = dw_hdmi_writeb; >> + hdmi->read = dw_hdmi_readb; >> + hdmi->reg_shift = 0; >> + } >> >> ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0); >> if (ddc_node) { > This should throw an error if the property value in devicetree is not > recognized. This could be simplified like this: > > u32 val = 1; > > // this won't touch val if it can't find the property > of_property_read_u32(np, "reg-io-width", &val) > > > switch (val) { > case 4: > hdmi->write = dw_hdmi_writel; > hdmi->read = dw_hdmi_readl; > hdmi->reg_shift = 2; > break; > case 1: > hdmi->write = dw_hdmi_writeb; > hdmi->read = dw_hdmi_readb; > hdmi->reg_shift = 0; > break; > default: > dev_err(dev, "unrecognized value for reg-io-width"); > // error handling > } > > Also the DT binding doc for this property is missing. > > Regards, > Lucas thanks for your suggestion, I will take it. this properity is optional, I will add it to DT binding doc
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 693a379..df76a8c 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -1503,8 +1503,11 @@ static int dw_hdmi_bind(struct device *dev, struct device *master, void *data) ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0); if (ddc_node) { hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node); - if (!hdmi->ddc) + if (!hdmi->ddc) { dev_dbg(hdmi->dev, "failed to read ddc node\n"); + of_node_put(ddc_node); + return -EPROBE_DEFER; + } of_node_put(ddc_node); } else {
drm driver may probe before the i2c bus, so the driver should defer probing untill it is avaliable Signed-off-by: Andy Yan <andy.yan@rock-chips.com> --- drivers/gpu/drm/bridge/dw_hdmi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)