[PATCH v4 23/23] drm/rockchip: dw-mipi-dsi: add reset control
From: briannorris@chromium.org (Brian Norris)
Date: 2017-03-02 22:09:11
Also in:
dri-devel, linux-rockchip, lkml
Oh, one more thing: On Fri, Feb 24, 2017 at 12:55:06PM +0000, John Keeping wrote:
quoted hunk ↗ jump to hunk
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);
Might want to check for -EPROBE_DEFER before printing an error? Brian
+ 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__);