On Thu, 16 Feb 2017 10:12:33 +0800, Chris Zhong wrote:
On 02/15/2017 08:39 PM, John Keeping wrote:
On Wed, 15 Feb 2017 11:38:45 +0800, Chris Zhong wrote:
On 01/29/2017 09:24 PM, John Keeping wrote:
In order to fully reset the state of the MIPI controller we must assert this reset.
This is slightly more complicated than it could be in order to maintain compatibility with device trees that do not specify the reset property.
Signed-off-by: John Keeping john@metanate.com Reviewed-by: Chris Zhong zyw@rock-chips.com
v3:
- Add Chris' Reviewed-by
Unchanged in v2
drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index 58cb8ace2fe8..cf3ca6b0cbdb 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -13,6 +13,7 @@ #include <linux/module.h> #include <linux/of_device.h> #include <linux/regmap.h> +#include <linux/reset.h> #include <linux/mfd/syscon.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_crtc.h> @@ -1124,6 +1125,7 @@ static int dw_mipi_dsi_bind(struct device *dev, struct device *master, of_match_device(dw_mipi_dsi_dt_ids, dev); const struct dw_mipi_dsi_plat_data *pdata = of_id->data; struct platform_device *pdev = to_platform_device(dev);
- struct reset_control *apb_rst; struct drm_device *drm = data; struct dw_mipi_dsi *dsi; struct resource *res;
@@ -1162,6 +1164,34 @@ static int dw_mipi_dsi_bind(struct device *dev, struct device *master, return ret; }
- /*
* Note that the reset was not defined in the initial device tree, so* we have to be prepared for it not being found.*/- apb_rst = devm_reset_control_get(dev, "apb");
- if (IS_ERR(apb_rst)) {
if (PTR_ERR(apb_rst) == -ENODEV) {According to [0], I think it should be -ENOENT here.
Nice catch, I'll fix this.
[0] https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=...
commit 3d81216fde465e76c5eae98f61d3666163634395 Author: Alban Bedel albeu@free.fr Date: Tue Sep 1 17:28:31 2015 +0200
reset: Fix of_reset_control_get() for consistent return values When of_reset_control_get() is called without connection ID it returns -ENOENT when the 'resets' property doesn't exists or is an empty entry. However when a connection ID is given it returns -EINVAL when the'resets' property doesn't exists or the requested name can't be found. This is because the error code returned by of_property_match_string() is just passed down as an index to of_parse_phandle_with_args(), which then returns -EINVAL.
To get a consistent return value with both code paths we must return -ENOENT when of_property_match_string() fails. Signed-off-by: Alban Bedel <albeu@free.fr> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
apb_rst = NULL;} else {dev_err(dev, "Unable to get reset control: %d\n", ret);Also, we can not get error number from "ret" here.
Good point, I'll fix this.
John