On Sun, Jan 29, 2017 at 01:24:43PM +0000, 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.
I always find it a little grating to see a device managed resource given to a local variable that is used immediately and only once. However, I think this might just be one of my twitches. So now that I've aired my grievance,
Reviewed-by: Sean Paul seanpaul@chromium.org
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) {apb_rst = NULL;} else {dev_err(dev, "Unable to get reset control: %d\n", ret);return PTR_ERR(apb_rst);}- }
- if (apb_rst) {
ret = clk_prepare_enable(dsi->pclk);if (ret) {dev_err(dev, "%s: Failed to enable pclk\n", __func__);return ret;}reset_control_assert(apb_rst);usleep_range(10, 20);reset_control_deassert(apb_rst);clk_disable_unprepare(dsi->pclk);- }
- ret = clk_prepare_enable(dsi->pllref_clk); if (ret) { dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
-- 2.11.0.197.gb556de5.dirty
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel