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authorJohn Keeping <john@metanate.com>2017-02-24 12:55:06 +0000
committerSean Paul <seanpaul@chromium.org>2017-03-01 14:48:59 -0500
commitf3b7a5b83896cb11deecab6aa30c5f53e19a83d5 (patch)
tree1680ed1758052419e5798c1a3ad10c5e2443e834 /drivers/gpu/drm/rockchip
parent03a5832c0ed8086fa0726d7160e936f71eccc25b (diff)
drm/rockchip: dw-mipi-dsi: add reset control
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> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: http://patchwork.freedesktop.org/patch/msgid/20170224125506.21533-24-john@metanate.com
Diffstat (limited to 'drivers/gpu/drm/rockchip')
-rw-r--r--drivers/gpu/drm/rockchip/dw-mipi-dsi.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
index 0c4bae711e84..30da75667334 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>
@@ -1144,6 +1145,7 @@ 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;
@@ -1182,6 +1184,35 @@ 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)) {
+ ret = PTR_ERR(apb_rst);
+ if (ret == -ENOENT) {
+ apb_rst = NULL;
+ } else {
+ dev_err(dev, "Unable to get reset control: %d\n", ret);
+ return ret;
+ }
+ }
+
+ 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__);