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Date:   Mon, 2 Jan 2023 15:32:14 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Rahul T R <r-ravikumar@ti.com>
Cc:     dri-devel@lists.freedesktop.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, tomi.valkeinen@ideasonboard.com,
        andrzej.hajda@intel.com, narmstrong@baylibre.com,
        robert.foss@linaro.org, jonas@kwiboo.se, jernej.skrabec@gmail.com,
        airlied@linux.ie, daniel@ffwll.ch, p.zabel@pengutronix.de,
        linux-kernel@vger.kernel.org, jpawar@cadence.com,
        sjakhade@cadence.com, mparab@cadence.com, a-bhatia1@ti.com,
        devicetree@vger.kernel.org, vigneshr@ti.com, lee.jones@linaro.org
Subject: Re: [PATCH v10 5/5] drm/bridge: cdns-dsi: Add support for J721E
 wrapper
Message-ID: <Y7Lc3m+EatH7x2w7@pendragon.ideasonboard.com>
References: <20230102100942.1828-1-r-ravikumar@ti.com>
 <20230102100942.1828-6-r-ravikumar@ti.com>
MIME-Version: 1.0
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In-Reply-To: <20230102100942.1828-6-r-ravikumar@ti.com>
Precedence: bulk

Hi Rahul,

Thank you for the patch.

On Mon, Jan 02, 2023 at 03:39:42PM +0530, Rahul T R wrote:
> Add support for wrapper settings for DSI bridge on
> j721e. Also enable DPI0
> 
> ---------------      -----------------------
> |      -------|      |-------              |
> | DSS  | DPI2 |----->| DPI0 |  DSI Wrapper |
> |      -------|      |-------              |
> ---------------      -----------------------
> 
> As shown above DPI2 output of DSS is connected
> to DPI0 input of DSI Wrapper, DSI wrapper
> gives control wheather to enable/disable DPI0
> input. In j721e above is the only configuration
> supported

You can also go up to 72 characters per line here :-)

> Signed-off-by: Rahul T R <r-ravikumar@ti.com>
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/gpu/drm/bridge/cadence/Kconfig        | 10 ++++
>  drivers/gpu/drm/bridge/cadence/Makefile       |  1 +
>  .../gpu/drm/bridge/cadence/cdns-dsi-core.c    | 35 ++++++++++++-
>  .../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   | 16 ++++++
>  6 files changed, 125 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..f8ea0393fe8a 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 DSI wrapper support"
> +	default y
> +	help
> +	  Support J721E Cadence DSI wrapper. The wrapper manages
> +	  the routing of the DSS DPI signal to the Cadence DSI.
> +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..a5b5dfbf09a0 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->deinit)
> +		dsi->platform_ops->deinit(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->deinit)
> +		dsi->platform_ops->deinit(dsi);
> +
>  	pm_runtime_disable(&pdev->dev);
>  
>  	return 0;
> @@ -864,6 +894,9 @@ 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, },
> +#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..2b1e96440c49 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;
> +

Please add kerneldoc to document the operations.

> +struct dsi_platform_ops {

Call this cdns_dsi_platform_ops, dsi_platform_ops is too generic.

> +	int (*init)(struct cdns_dsi *dsi);
> +	void (*deinit)(struct cdns_dsi *dsi);
> +	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@ti.com>
> + */
> +
> +#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..fd251c1a268b
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-j721e.h
> @@ -0,0 +1,16 @@
> +/* 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@ti.com>
> + */
> +
> +#ifndef CDNS_DSI_J721E_H

__ prefix for header guard ?

> +#define CDNS_DSI_J721E_H
> +
> +#include "cdns-dsi-core.h"
> +
> +extern const struct dsi_platform_ops dsi_ti_j721e_ops;
> +
> +#endif /* !CDNS_DSI_J721E_H */

-- 
Regards,

Laurent Pinchart