On Sat, 2021-04-24 at 07:50 +0800, Chun-Kuang Hu wrote:
> Hi, Jitao:
>
> Jitao Shi <jitao.shi@xxxxxxxxxxxx> 於 2021年4月20日 週二 下午9:26寫道：
> >
> > Reset dsi HW to default when power on. Prevent the setting differet
> > between bootloader and kernel.
> >
> > Signed-off-by: Jitao Shi <jitao.shi@xxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/mediatek/mtk_dsi.c | 36 +++++++++++++++++++++++++++++-
> > 1 file changed, 35 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index 455fe582c6b5..113438ddd4cc 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -7,10 +7,12 @@
> > #include <linux/component.h>
> > #include <linux/iopoll.h>
> > #include <linux/irq.h>
> > +#include <linux/mfd/syscon.h>
> > #include <linux/of.h>
> > #include <linux/of_platform.h>
> > #include <linux/phy/phy.h>
> > #include <linux/platform_device.h>
> > +#include <linux/regmap.h>
> >
> > #include <video/mipi_display.h>
> > #include <video/videomode.h>
> > @@ -143,6 +145,8 @@
> > #define DATA_0 (0xff << 16)
> > #define DATA_1 (0xff << 24)
> >
> > +#define MMSYS_SW_RST_DSI_B BIT(25)
> > +
> > #define NS_TO_CYCLE(n, c) ((n) / (c) + (((n) % (c)) ? 1 : 0))
> >
> > #define MTK_DSI_HOST_IS_READ(type) \
> > @@ -186,7 +190,8 @@ struct mtk_dsi {
> > struct drm_bridge *next_bridge;
> > struct drm_connector *connector;
> > struct phy *phy;
> > -
> > + struct regmap *mmsys_sw_rst_b;
> > + u32 sw_rst_b;
> > void __iomem *regs;
> >
> > struct clk *engine_clk;
> > @@ -272,6 +277,16 @@ static void mtk_dsi_disable(struct mtk_dsi *dsi)
> > mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_EN, 0);
> > }
> >
> > +static void mtk_dsi_reset_all(struct mtk_dsi *dsi)
> > +{
> > + regmap_update_bits(dsi->mmsys_sw_rst_b, dsi->sw_rst_b,
> > + MMSYS_SW_RST_DSI_B, 0);
> > + usleep_range(1000, 1100);
> > +
> > + regmap_update_bits(dsi->mmsys_sw_rst_b, dsi->sw_rst_b,
> > + MMSYS_SW_RST_DSI_B, MMSYS_SW_RST_DSI_B);
> > +}
> > +
> > static void mtk_dsi_reset_engine(struct mtk_dsi *dsi)
> > {
> > mtk_dsi_mask(dsi, DSI_CON_CTRL, DSI_RESET, DSI_RESET);
> > @@ -985,6 +1000,8 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
> >
> > ret = mtk_dsi_encoder_init(drm, dsi);
> >
> > + mtk_dsi_reset_all(dsi);
> > +
> > return ret;
> > }
> >
> > @@ -1007,6 +1024,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> > struct device *dev = &pdev->dev;
> > struct drm_panel *panel;
> > struct resource *regs;
> > + struct regmap *regmap;
> > int irq_num;
> > int ret;
> >
> > @@ -1022,6 +1040,22 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> > return ret;
> > }
> >
> > + regmap = syscon_regmap_lookup_by_phandle(dev->of_node,
> > + "mediatek,syscon-dsi");
> > + ret = of_property_read_u32_index(dev->of_node, "mediatek,syscon-dsi", 1,
> > + &dsi->sw_rst_b);
> > +
> > + if (IS_ERR(regmap))
> > + ret = PTR_ERR(regmap);
> > +
> > + if (ret) {
> > + ret = PTR_ERR(regmap);
> > + dev_err(dev, "Failed to get mmsys registers: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + dsi->mmsys_sw_rst_b = regmap;
> > +
>
> It looks like that mtk-mmsys is the reset controller and mtk-dsi is
> reset consumer. Please refer to [1], [2] to implement.
>
> [1] https://www.kernel.org/doc/html/latest/driver-api/reset.html
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/reset/reset.txt?h=v5.12-rc8
>
> Regards,
> Chun-Kuang.
>
Thanks, I'll fix next version.
> > ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> > &panel, &dsi->next_bridge);
> > if (ret)
> > --
> > 2.25.1
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