Re: [PATCH v8 5/5] drm/bridge: cdns-dsi: Add support for J721E wrapper

From: Rahul T R
Date: Mon Oct 31 2022 - 08:24:32 EST

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In reply to: Tomi Valkeinen: "Re: [PATCH v8 5/5] drm/bridge: cdns-dsi: Add support for J721E wrapper"
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Hi Tomi,

On 09:12-20221026, Tomi Valkeinen wrote:
> Hi,
>
> On 21/10/2022 20:18, Rahul T R wrote:
> > Add support for wrapper settings for DSI bridge on
> > j721e. Also set the DPI input to DPI0
>
> I think a few more words on the HW layout would be nice. What does the
> wrapper do and how is it connected to the DSS.
>
> > Signed-off-by: Rahul T R <r-ravikumar@xxxxxx>
> > ---
> > drivers/gpu/drm/bridge/cadence/Kconfig | 10 ++++
> > drivers/gpu/drm/bridge/cadence/Makefile | 1 +
> > .../gpu/drm/bridge/cadence/cdns-dsi-core.c | 37 +++++++++++++-
> > .../gpu/drm/bridge/cadence/cdns-dsi-core.h | 13 +++++
> > .../gpu/drm/bridge/cadence/cdns-dsi-j721e.c | 51 +++++++++++++++++++
> > .../gpu/drm/bridge/cadence/cdns-dsi-j721e.h | 18 +++++++
> > 6 files changed, 129 insertions(+), 1 deletion(-)
> > create mode 100644 drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.c
> > create mode 100644 drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.h
> >
> > diff --git a/drivers/gpu/drm/bridge/cadence/Kconfig b/drivers/gpu/drm/bridge/cadence/Kconfig
> > index 8fbb46c66094..663a02d96420 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Kconfig
> > +++ b/drivers/gpu/drm/bridge/cadence/Kconfig
> > @@ -36,3 +36,13 @@ config DRM_CDNS_DSI
> > help
> > Support Cadence DPI to DSI bridge. This is an internal
> > bridge and is meant to be directly embedded in a SoC.
> > +
> > +if DRM_CDNS_DSI
> > +
> > +config DRM_CDNS_DSI_J721E
> > + bool "J721E Cadence DPI/DSI wrapper support"
> > + default y
> > + help
> > + Support J721E Cadence DPI/DSI wrapper. This wrapper adds
> > + support to select which DPI input to use for the bridge.
>
> I'm not sure if the above is quite necessary here. If I understand right,
> there's only one way on J721E to mux the DPI signal going to the DSI. If you
> write "adds support to select DPI input" it sounds like there's something to
> select, and this config somehow enables that selection for the user.
>
> Perhaps instead just say something like "Support J721E Cadence DPI/DSI
> wrapper. The wrapper manages the routing of the DSS DPI signal to the
> Cadence DSI.", or something along those lines.
>
> Also, you say "DPI/DSI wrapper". How does this wrap DPI? Isn't this just a
> DSI wrapper?
>
> > +endif
> > diff --git a/drivers/gpu/drm/bridge/cadence/Makefile b/drivers/gpu/drm/bridge/cadence/Makefile
> > index e3d8e9a40784..4cffc8ff71c4 100644
> > --- a/drivers/gpu/drm/bridge/cadence/Makefile
> > +++ b/drivers/gpu/drm/bridge/cadence/Makefile
> > @@ -4,3 +4,4 @@ cdns-mhdp8546-y := cdns-mhdp8546-core.o cdns-mhdp8546-hdcp.o
> > cdns-mhdp8546-$(CONFIG_DRM_CDNS_MHDP8546_J721E) += cdns-mhdp8546-j721e.o
> > obj-$(CONFIG_DRM_CDNS_DSI) += cdns-dsi.o
> > cdns-dsi-y := cdns-dsi-core.o
> > +cdns-dsi-$(CONFIG_DRM_CDNS_DSI_J721E) += cdns-dsi-j721e.o
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> > index cba91247ab26..4b7de38ef1b0 100644
> > --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> > @@ -15,12 +15,16 @@
> > #include <linux/iopoll.h>
> > #include <linux/module.h>
> > #include <linux/of_address.h>
> > +#include <linux/of_device.h>
> > #include <linux/of_graph.h>
> > #include <linux/platform_device.h>
> > #include <linux/pm_runtime.h>
> > #include <linux/reset.h>
> > #include "cdns-dsi-core.h"
> > +#ifdef CONFIG_DRM_CDNS_DSI_J721E
> > +#include "cdns-dsi-j721e.h"
> > +#endif
> > static inline struct cdns_dsi *input_to_dsi(struct cdns_dsi_input *input)
> > {
> > @@ -265,6 +269,10 @@ static void cdns_dsi_bridge_disable(struct drm_bridge *bridge)
> > val = readl(dsi->regs + MCTL_MAIN_EN) & ~IF_EN(input->id);
> > writel(val, dsi->regs + MCTL_MAIN_EN);
> > +
> > + if (dsi->platform_ops && dsi->platform_ops->disable)
> > + dsi->platform_ops->disable(dsi);
> > +
> > pm_runtime_put(dsi->base.dev);
> > }
> > @@ -360,6 +368,9 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
> > if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0))
> > return;
> > + if (dsi->platform_ops && dsi->platform_ops->enable)
> > + dsi->platform_ops->enable(dsi);
> > +
> > mode = &bridge->encoder->crtc->state->adjusted_mode;
> > nlanes = output->dev->lanes;
> > @@ -800,6 +811,8 @@ static int cdns_dsi_drm_probe(struct platform_device *pdev)
> > goto err_disable_pclk;
> > }
> > + dsi->platform_ops = of_device_get_match_data(&pdev->dev);
> > +
> > val = readl(dsi->regs + IP_CONF);
> > dsi->direct_cmd_fifo_depth = 1 << (DIRCMD_FIFO_DEPTH(val) + 2);
> > dsi->rx_fifo_depth = RX_FIFO_DEPTH(val);
> > @@ -835,14 +848,27 @@ static int cdns_dsi_drm_probe(struct platform_device *pdev)
> > dsi->base.dev = &pdev->dev;
> > dsi->base.ops = &cdns_dsi_ops;
> > + if (dsi->platform_ops && dsi->platform_ops->init) {
> > + ret = dsi->platform_ops->init(dsi);
> > + if (ret != 0) {
> > + dev_err(&pdev->dev, "platform initialization failed: %d\n",
> > + ret);
> > + goto err_disable_runtime_pm;
> > + }
> > + }
> > +
> > ret = mipi_dsi_host_register(&dsi->base);
> > if (ret)
> > - goto err_disable_runtime_pm;
> > + goto err_deinit_platform;
> > clk_disable_unprepare(dsi->dsi_p_clk);
> > return 0;
> > +err_deinit_platform:
> > + if (dsi->platform_ops && dsi->platform_ops->exit)
> > + dsi->platform_ops->exit(dsi);
> > +
> > err_disable_runtime_pm:
> > pm_runtime_disable(&pdev->dev);
> > @@ -857,6 +883,10 @@ static int cdns_dsi_drm_remove(struct platform_device *pdev)
> > struct cdns_dsi *dsi = platform_get_drvdata(pdev);
> > mipi_dsi_host_unregister(&dsi->base);
> > +
> > + if (dsi->platform_ops && dsi->platform_ops->exit)
> > + dsi->platform_ops->exit(dsi);
> > +
> > pm_runtime_disable(&pdev->dev);
> > return 0;
> > @@ -864,6 +894,11 @@ static int cdns_dsi_drm_remove(struct platform_device *pdev)
> > static const struct of_device_id cdns_dsi_of_match[] = {
> > { .compatible = "cdns,dsi" },
> > +#ifdef CONFIG_DRM_CDNS_DSI_J721E
> > + { .compatible = "ti,j721e-dsi",
> > + .data = &dsi_ti_j721e_ops,
> > + },
>
> I find the above formatting a bit odd. I think this should do fine:
>
> { .compatible = "ti,j721e-dsi", .data = &dsi_ti_j721e_ops, },
>
> If you want multi-line, then I think the opening { should be on its own
> line, similarly to the closing }.
>
> > +#endif
> > { },
> > };
> > MODULE_DEVICE_TABLE(of, cdns_dsi_of_match);
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h
> > index 65cc77f19b39..37568b547fbe 100644
> > --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.h
> > @@ -439,9 +439,22 @@ struct cdns_dsi_input {
> > struct drm_bridge bridge;
> > };
> > +struct cdns_dsi;
> > +
> > +struct dsi_platform_ops {
> > + int (*init)(struct cdns_dsi *dsi);
> > + void (*exit)(struct cdns_dsi *dsi);
>
> I don't think init and exit are the opposites, but rather init and
> deinit/uninit.
>
> > + void (*enable)(struct cdns_dsi *dsi);
> > + void (*disable)(struct cdns_dsi *dsi);
> > +};
> > +
> > struct cdns_dsi {
> > struct mipi_dsi_host base;
> > void __iomem *regs;
> > +#ifdef CONFIG_DRM_CDNS_DSI_J721E
> > + void __iomem *j721e_regs;
> > +#endif
> > + const struct dsi_platform_ops *platform_ops;
> > struct cdns_dsi_input input;
> > struct cdns_dsi_output output;
> > unsigned int direct_cmd_fifo_depth;
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.c
> > new file mode 100644
> > index 000000000000..b5216acb333e
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.c
> > @@ -0,0 +1,51 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * TI j721e Cadence DSI wrapper
> > + *
> > + * Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
> > + * Author: Rahul T R <r-ravikumar@xxxxxx>
> > + */
> > +
> > +#include <linux/io.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include "cdns-dsi-j721e.h"
> > +
> > +#define DSI_WRAP_REVISION 0x0
> > +#define DSI_WRAP_DPI_CONTROL 0x4
> > +#define DSI_WRAP_DSC_CONTROL 0x8
> > +#define DSI_WRAP_DPI_SECURE 0xc
> > +#define DSI_WRAP_DSI_0_ASF_STATUS 0x10
> > +
> > +#define DSI_WRAP_DPI_0_EN BIT(0)
> > +#define DSI_WRAP_DSI2_MUX_SEL BIT(4)
> > +
> > +static int cdns_dsi_j721e_init(struct cdns_dsi *dsi)
> > +{
> > + struct platform_device *pdev = to_platform_device(dsi->base.dev);
> > +
> > + dsi->j721e_regs = devm_platform_ioremap_resource(pdev, 1);
> > + return PTR_ERR_OR_ZERO(dsi->j721e_regs);
> > +}
> > +
> > +static void cdns_dsi_j721e_enable(struct cdns_dsi *dsi)
> > +{
> > + /*
> > + * Enable DPI0 as its input. DSS0 DPI2 is connected
> > + * to DSI DPI0. This is the only supported configuration on
> > + * J721E.
> > + */
> > + writel(DSI_WRAP_DPI_0_EN, dsi->j721e_regs + DSI_WRAP_DPI_CONTROL);
> > +}
> > +
> > +static void cdns_dsi_j721e_disable(struct cdns_dsi *dsi)
> > +{
> > + /* Put everything to defaults */
> > + writel(0, dsi->j721e_regs + DSI_WRAP_DPI_CONTROL);
> > +}
> > +
> > +const struct dsi_platform_ops dsi_ti_j721e_ops = {
> > + .init = cdns_dsi_j721e_init,
> > + .enable = cdns_dsi_j721e_enable,
> > + .disable = cdns_dsi_j721e_disable,
> > +};
> > diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.h b/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.h
> > new file mode 100644
> > index 000000000000..01f3dbd92db2
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.h
> > @@ -0,0 +1,18 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * TI j721e Cadence DSI wrapper
> > + *
> > + * Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
> > + * Author: Rahul T R <r-ravikumar@xxxxxx>
> > + */
> > +
> > +#ifndef CDNS_DSI_J721E_H
> > +#define CDNS_DSI_J721E_H
> > +
> > +#include "cdns-dsi-core.h"
> > +
> > +struct dsi_platform_ops;
>
> You don't need the above line as you already include the cdns-dsi-core.h
>

Thanks for the detailed review
I have addressed the review comments
and sent a v9 of this series

Regards
Rahul T R

> > +extern const struct dsi_platform_ops dsi_ti_j721e_ops;
> > +
> > +#endif /* !CDNS_DSI_J721E_H */
>

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Previous message: Ajye Huang: "[PATCH v5 2/2] ASoC: mediatek: mt8186-rt5682: Modify machine driver for two DMICs case"
In reply to: Tomi Valkeinen: "Re: [PATCH v8 5/5] drm/bridge: cdns-dsi: Add support for J721E wrapper"
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