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Subject: Re: [PATCH] display/bridge: dsi2lvds tc358775 driver
To:     Vinay Simha BN <simhavcs@gmail.com>
Cc:     "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Jernej Skrabec <jernej.skrabec@siol.net>,
        Neil Armstrong <narmstrong@baylibre.com>,
        David Airlie <airlied@linux.ie>,
        Jonas Karlman <jonas@kwiboo.se>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>,
        Rob Herring <robh+dt@kernel.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
From:   Andrzej Hajda <a.hajda@samsung.com>
Message-ID: <01e0b365-6c72-c199-9fb5-2f6fa7f77335@samsung.com>
Date:   Tue, 3 Mar 2020 16:09:20 +0100
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        <1582812239-29480-1-git-send-email-simhavcs@gmail.com>
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On 27.02.2020 15:03, Vinay Simha BN wrote:
> dsi2lvds tc358775 bridge driver added
> Tested in apq8016, ifc6309 board and panel
> auo,b101xtn01


Just FYI, there exists already TC358764/5 driver for similar hw, but
controlled via DSI bus.


> Signed-off-by: Vinay Simha BN <simhavcs@gmail.com>
> ---
>  .../bindings/display/bridge/toshiba,tc358775.txt   | 106 ++++


Bindings should be in separate patch and in yaml format.


>  drivers/gpu/drm/bridge/Kconfig                     |  10 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/tc358775.c                  | 687 +++++++++++++++++++++
>  4 files changed, 804 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.txt
>  create mode 100644 drivers/gpu/drm/bridge/tc358775.c
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.txt b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.txt
> new file mode 100644
> index 0000000..c4c364d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/toshiba,tc358775.txt
> @@ -0,0 +1,106 @@
> +Toshiba TC358775 DSI to LVDS bridge bindings
> +
> +Required properties:
> + - compatible: "toshiba,tc358775"
> + - reg: i2c address of the bridge, 0x0f
> + - tc, dsi-lanes: Number of DSI data lanes connected to the DSI host. It should
> +  be one of 1, 2, 3 or 4.
> + - tc, dual-link : To configure the LVDS transmitter either
> +  as single-link or dual-link.
> + - tc, data-format: To configure the data formats
> +   0 for VESA standard, 1 for JEIDA standard


IMO, three properties above should be received from downstream device in
runtime, not hardcoded into DT, however I am not sure if frameworks
support it.

> + - vdd-supply: 1.2V LVDS Power Supply
> + - vddio-supply: 1.8V IO Power Supply
> + - stby-gpios: Standby pin, Low active 
> + - reset-gpios: Hardware reset,	Low active 
> +
> +Required nodes:
> +
> +The TC358775 has two ports. Their connections are modelled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> +
> +- Video port 0 for the DSI input. The remote endpoint phandle should be a
> +	reference to a valid mipi_dsi_host device node.
> +- Video port 1 for the LVDS output.
> +
> +Example:
> +
> +	i2c@78b8000 {
> +		/* On High speed expansion */
> +		label = "HS-I2C2";
> +		status = "okay";
> +
> +		tc_bridge: bridge@f {
> +			status = "okay";
> +
> +			compatible = "toshiba,tc358775";
> +			reg = <0x0f>;
> +
> +			tc,dsi-lanes = <4>;
> +			tc,dual-link = <0>;
> +			tc,data-format = <1>;
> +
> +			vdd-supply = <&pm8916_l2>;
> +			vddio-supply = <&pm8916_l6>;
> +
> +			stby-gpio = <&msmgpio 99 GPIO_ACTIVE_LOW>;
> +			reset-gpio = <&msmgpio 72 GPIO_ACTIVE_LOW>;
> +
> +			ports {
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +
> +				port@0 {
> +					reg = <0>;
> +					d2l_in: endpoint {
> +						remote-endpoint = <&dsi0_out>;
> +					};
> +				};
> +
> +				port@1 {
> +					reg = <1>;
> +					d2l_out: endpoint {
> +						remote-endpoint = <&panel_in>;
> +					};
> +				};
> +			};
> +		};
> +	};
> +
> +	panel: auo,b101xtn01 {
> +			status = "okay";
> +			compatible = "auo,b101xtn01";
> +			power-supply = <&pm8916_l14>;
> +
> +			port {
> +				panel_in: endpoint {
> +					remote-endpoint = <&d2l_out>;
> +				};
> +			};
> +	};
> +
> +	mdss@1a00000 {
> +		status = "okay";
> +
> +		mdp@1a01000 {
> +			status = "okay";
> +		};
> +
> +		dsi@1a98000 {
> +			status = "okay";
> +			..
> +			ports {
> +				port@1 {
> +					dsi0_out: endpoint {
> +						remote-endpoint = <&d2l_in>;
> +						data-lanes = <0 1 2 3>;
> +					};
> +				};
> +			};
> +		};
> +
> +		dsi-phy@1a98300 {
> +			status = "okay";
> +			..
> +		};
> +	};
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 8397bf7..d5528fa 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -133,6 +133,16 @@ config DRM_TOSHIBA_TC358767
>  	---help---
>  	  Toshiba TC358767 eDP bridge chip driver.
>  
> +config DRM_TOSHIBA_TC358775
> +        tristate "Toshiba TC358775 LVDS bridge"
> +        depends on OF
> +        select DRM_KMS_HELPER
> +        select REGMAP_I2C
> +        select DRM_PANEL
> +	select DRM_MIPI_DSI
> +        ---help---
> +          Toshiba TC358775 LVDS bridge chip driver.
> +
>  config DRM_TI_TFP410
>  	tristate "TI TFP410 DVI/HDMI bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 1eb5376..9b2c512 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_SII9234) += sii9234.o
>  obj-$(CONFIG_DRM_THINE_THC63LVD1024) += thc63lvd1024.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358764) += tc358764.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
> +obj-$(CONFIG_DRM_TOSHIBA_TC358775) += tc358775.o
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
>  obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
>  obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
> diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c
> new file mode 100644
> index 0000000..3db0f49
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/tc358775.c
> @@ -0,0 +1,687 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * tc358775 DSI to LVDS bridge driver
> + *
> + * Copyright (C) 2020 InforceComputing
> + * Author: Vinay Simha BN <vinaysimha@inforcecomputing.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.


You can drop these statements, SPDX identifier is enough.


> + */
> +
> +/* #define DEBUG */
> +/* #define TC358775_DEBUG */


Please remove these development leftovers.


> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/regulator/consumer.h>
Alphabetic order.
> +
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_dp_helper.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_bridge.h>
> +#include <drm/drm_probe_helper.h>
ditto
> +
> +/* Registers */
> +
> +/* DSI D-PHY Layer Registers */
> +#define D0W_DPHYCONTTX  0x0004  /* Data Lane 0 DPHY Tx Control */
> +#define CLW_DPHYCONTRX  0x0020  /* Clock Lane DPHY Rx Control */
> +#define D0W_DPHYCONTRX  0x0024  /* Data Lane 0 DPHY Rx Control */
> +#define D1W_DPHYCONTRX  0x0028  /* Data Lane 1 DPHY Rx Control */
> +#define D2W_DPHYCONTRX  0x002C  /* Data Lane 2 DPHY Rx Control */
> +#define D3W_DPHYCONTRX  0x0030  /* Data Lane 3 DPHY Rx Control */
> +#define COM_DPHYCONTRX  0x0038  /* DPHY Rx Common Control */
> +#define CLW_CNTRL       0x0040  /* Clock Lane Control */
> +#define D0W_CNTRL       0x0044  /* Data Lane 0 Control */
> +#define D1W_CNTRL       0x0048  /* Data Lane 1 Control */
> +#define D2W_CNTRL       0x004C  /* Data Lane 2 Control */
> +#define D3W_CNTRL       0x0050  /* Data Lane 3 Control */
> +#define DFTMODE_CNTRL   0x0054  /* DFT Mode Control */
> +
> +/* DSI PPI Layer Registers */
> +#define PPI_STARTPPI    0x0104  /* START control bit of PPI-TX function. */
> +#define PPI_BUSYPPI     0x0108
> +#define PPI_LINEINITCNT 0x0110  /* Line Initialization Wait Counter  */
> +#define PPI_LPTXTIMECNT 0x0114
> +#define PPI_LANEENABLE  0x0134  /* Enables each lane at the PPI layer. */
> +#define PPI_TX_RX_TA    0x013C  /* DSI Bus Turn Around timing parameters */
> +
> +/* Analog timer function enable */
> +#define PPI_CLS_ATMR    0x0140  /* Delay for Clock Lane in LPRX  */
> +#define PPI_D0S_ATMR    0x0144  /* Delay for Data Lane 0 in LPRX */
> +#define PPI_D1S_ATMR    0x0148  /* Delay for Data Lane 1 in LPRX */
> +#define PPI_D2S_ATMR    0x014C  /* Delay for Data Lane 2 in LPRX */
> +#define PPI_D3S_ATMR    0x0150  /* Delay for Data Lane 3 in LPRX */
> +#define PPI_D0S_CLRSIPOCOUNT    0x0164
> +
> +#define PPI_D1S_CLRSIPOCOUNT    0x0168  /* For lane 1 */
> +#define PPI_D2S_CLRSIPOCOUNT    0x016C  /* For lane 2 */
> +#define PPI_D3S_CLRSIPOCOUNT    0x0170  /* For lane 3 */
> +
> +#define CLS_PRE         0x0180  /* Digital Counter inside of PHY IO */
> +#define D0S_PRE         0x0184  /* Digital Counter inside of PHY IO */
> +#define D1S_PRE         0x0188  /* Digital Counter inside of PHY IO */
> +#define D2S_PRE         0x018C  /* Digital Counter inside of PHY IO */
> +#define D3S_PRE         0x0190  /* Digital Counter inside of PHY IO */
> +#define CLS_PREP        0x01A0  /* Digital Counter inside of PHY IO */
> +#define D0S_PREP        0x01A4  /* Digital Counter inside of PHY IO */
> +#define D1S_PREP        0x01A8  /* Digital Counter inside of PHY IO */
> +#define D2S_PREP        0x01AC  /* Digital Counter inside of PHY IO */
> +#define D3S_PREP        0x01B0  /* Digital Counter inside of PHY IO */
> +#define CLS_ZERO        0x01C0  /* Digital Counter inside of PHY IO */
> +#define D0S_ZERO        0x01C4  /* Digital Counter inside of PHY IO */
> +#define D1S_ZERO        0x01C8  /* Digital Counter inside of PHY IO */
> +#define D2S_ZERO        0x01CC  /* Digital Counter inside of PHY IO */
> +#define D3S_ZERO        0x01D0  /* Digital Counter inside of PHY IO */
> +
> +#define PPI_CLRFLG      0x01E0  /* PRE Counters has reached set values */
> +#define PPI_CLRSIPO     0x01E4  /* Clear SIPO values, Slave mode use only. */
> +#define HSTIMEOUT       0x01F0  /* HS Rx Time Out Counter */
> +#define HSTIMEOUTENABLE 0x01F4  /* Enable HS Rx Time Out Counter */
> +#define DSI_STARTDSI    0x0204  /* START control bit of DSI-TX function */
> +#define DSI_BUSYDSI     0x0208
> +#define DSI_LANEENABLE  0x0210  /* Enables each lane at the Protocol layer. */
> +#define DSI_LANESTATUS0 0x0214  /* Displays lane is in HS RX mode. */
> +#define DSI_LANESTATUS1 0x0218  /* Displays lane is in ULPS or STOP state */
> +
> +#define DSI_INTSTATUS   0x0220  /* Interrupt Status */
> +#define DSI_INTMASK     0x0224  /* Interrupt Mask */
> +#define DSI_INTCLR      0x0228  /* Interrupt Clear */
> +#define DSI_LPTXTO      0x0230  /* Low Power Tx Time Out Counter */
> +
> +#define DSIERRCNT       0x0300  /* DSI Error Count */
> +#define APLCTRL         0x0400  /* Application Layer Control */
> +#define RDPKTLN         0x0404  /* Command Read Packet Length */
> +
> +#define VPCTRL          0x0450  /* Video Path Control */
> +#define HTIM1           0x0454  /* Horizontal Timing Control 1 */
> +#define HTIM2           0x0458  /* Horizontal Timing Control 2 */
> +#define VTIM1           0x045C  /* Vertical Timing Control 1 */
> +#define VTIM2           0x0460  /* Vertical Timing Control 2 */
> +#define VFUEN           0x0464  /* Video Frame Timing Update Enable */
> +
> +/* Mux Input Select for LVDS LINK Input */
> +#define LVMX0003        0x0480  /* Bit 0 to 3 */
> +#define LVMX0407        0x0484  /* Bit 4 to 7 */
> +#define LVMX0811        0x0488  /* Bit 8 to 11 */
> +#define LVMX1215        0x048C  /* Bit 12 to 15 */
> +#define LVMX1619        0x0490  /* Bit 16 to 19 */
> +#define LVMX2023        0x0494  /* Bit 20 to 23 */
> +#define LVMX2427        0x0498  /* Bit 24 to 27 */
> +
> +#define LVCFG           0x049C  /* LVDS Configuration  */
> +#define LVPHY0          0x04A0  /* LVDS PHY 0 */
> +#define LVPHY1          0x04A4  /* LVDS PHY 1 */
> +#define SYSSTAT         0x0500  /* System Status  */
> +#define SYSRST          0x0504  /* System Reset  */
> +/* GPIO Registers */
> +#define GPIOC           0x0520  /* GPIO Control  */
> +#define GPIOO           0x0524  /* GPIO Output  */
> +#define GPIOI           0x0528  /* GPIO Input  */
> +
> +/* I2C Registers */
> +#define I2CTIMCTRL      0x0540  /* I2C IF Timing and Enable Control */
> +#define I2CMADDR        0x0544  /* I2C Master Addressing */
> +#define WDATAQ          0x0548  /* Write Data Queue */
> +#define RDATAQ          0x054C  /* Read Data Queue */
> +
> +/* Chip ID and Revision ID Register */
> +#define IDREG           0x0580
> +
> +#define TC358775XBG_ID  0x00007500
> +
> +/* Debug Registers */
> +#define DEBUG00         0x05A0  /* Debug */
> +#define DEBUG01         0x05A4  /* LVDS Data */
> +
> +#define DSI_CLEN_BIT		BIT(0)
> +#define DIVIDE_BY_3		3 /* PCLK=DCLK/3 */
> +#define LVCFG_LVEN_BIT		BIT(0)
> +
> +#define L0EN BIT(1)
> +
> +#define TC358775_VPCTRL_VSDELAY__MASK	0x3FF00000
> +#define TC358775_VPCTRL_VSDELAY__SHIFT	20
> +static inline uint32_t TC358775_VPCTRL_VSDELAY(uint32_t val)


Use u32 here and below, unit32_t is mainly for userspace interactions.


> +{
> +	return ((val) << TC358775_VPCTRL_VSDELAY__SHIFT) &
> +			TC358775_VPCTRL_VSDELAY__MASK;
> +}
> +
> +#define TC358775_VPCTRL_OPXLFMT__MASK	0x00000100
> +#define TC358775_VPCTRL_OPXLFMT__SHIFT	8
> +static inline uint32_t TC358775_VPCTRL_OPXLFMT(uint32_t val)
> +{
> +	return ((val) << TC358775_VPCTRL_OPXLFMT__SHIFT) &
> +			TC358775_VPCTRL_OPXLFMT__MASK;
> +}
> +
> +#define TC358775_VPCTRL_MSF__MASK	0x00000001
> +#define TC358775_VPCTRL_MSF__SHIFT	0
> +static inline uint32_t TC358775_VPCTRL_MSF(uint32_t val)
> +{
> +	return ((val) << TC358775_VPCTRL_MSF__SHIFT) &
> +			TC358775_VPCTRL_MSF__MASK;
> +}
> +
> +#define TC358775_LVCFG_PCLKDIV__MASK	0x000000f0
> +#define TC358775_LVCFG_PCLKDIV__SHIFT	4
> +static inline uint32_t TC358775_LVCFG_PCLKDIV(uint32_t val)
> +{
> +	return ((val) << TC358775_LVCFG_PCLKDIV__SHIFT) &
> +			TC358775_LVCFG_PCLKDIV__MASK;
> +}
> +
> +#define TC358775_LVCFG_LVDLINK__MASK                         0x00000002
> +#define TC358775_LVCFG_LVDLINK__SHIFT                        0
> +static inline uint32_t TC358775_LVCFG_LVDLINK(uint32_t val)
> +{
> +	return ((val) << TC358775_LVCFG_LVDLINK__SHIFT) &
> +			TC358775_LVCFG_LVDLINK__MASK;
> +}
> +
> +static const struct reg_sequence tc_fixed_registers[] = {
> +	{ 0x013C, 0x00040006 },
> +	{ 0x0114, 0x00000004 },
> +	{ 0x0164, 0x00000003 },
> +	{ 0x0168, 0x00000003 },
> +	{ 0x016C, 0x00000003 },
> +	{ 0x0170, 0x00000003 },


use macros instead of magic numbers.


> +};
> +
> +static const struct reg_sequence tc_vesa_data_format_registers[] = {
> +	{ 0x0480, 0x03020100 },
> +	{ 0x0484, 0x08050704 },
> +	{ 0x0488, 0x0F0E0A09 },
> +	{ 0x048C, 0x100D0C0B },
> +	{ 0x0490, 0x12111716 },
> +	{ 0x0494, 0x1B151413 },
> +	{ 0x0498, 0x061A1918 },
ditto
> +};
> +
> +static const char * const regulator_names[] = {
> +	"vdd",
> +	"vddio"
> +};
> +
> +struct tc_data {
> +	struct i2c_client	*i2c;
> +
> +	struct device		*dev;
> +	struct regmap		*regmap;
> +
> +	struct drm_bridge	bridge;
> +	struct drm_connector	connector;
> +	struct drm_panel	*panel;
> +
> +	enum drm_connector_status status;
unused field
> +	struct device_node *host_node;
> +	struct mipi_dsi_device *dsi;
> +	u8 num_dsi_lanes;
> +
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
> +	struct gpio_desc	*reset_gpio;
> +	struct gpio_desc	*stby_gpio;
> +	u32                     rev;
> +	u8                      dual_link; /* single-link or dual-link */
> +	u8			data_format; /* VESA or JEIDA */
> +};
> +
> +static inline struct tc_data *bridge_to_tc(struct drm_bridge *b)
> +{
> +	return container_of(b, struct tc_data, bridge);
> +}
> +
> +static inline struct tc_data *connector_to_tc(struct drm_connector *c)
> +{
> +	return container_of(c, struct tc_data, connector);
> +}
> +
> +static void tc_bridge_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct tc_data *tc = bridge_to_tc(bridge);
> +	struct device *dev = &tc->dsi->dev;
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(tc->supplies), tc->supplies);
> +	if (ret < 0) {
> +		dev_err(dev, "regulator enable failed, %d\n", ret);
> +		return;
> +	}
> +	mdelay(10);
> +
> +	gpiod_set_value(tc->stby_gpio, 0);
> +	mdelay(10);
> +
> +	gpiod_set_value(tc->reset_gpio, 0);
> +	ndelay(50);
> +
> +	drm_panel_prepare(tc->panel);
> +}
> +
> +static void tc_bridge_disable(struct drm_bridge *bridge)
> +{
> +	struct tc_data *tc = bridge_to_tc(bridge);
> +	struct device *dev = &tc->dsi->dev;
> +	int ret;
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(tc->supplies), tc->supplies);
> +	if (ret < 0)
> +		dev_err(dev, "regulator disable failed, %d\n", ret);
> +	mdelay(10);
> +
> +	gpiod_set_value(tc->stby_gpio, 1);
> +	mdelay(10);
> +
> +	gpiod_set_value(tc->reset_gpio, 1);
> +	ndelay(50);
> +
> +	drm_panel_disable(tc->panel);

I suspect the order should be different - ie reverse to the one pre_enable.

Moreover since it reverts pre_enable it should be put into post_disable
(except drm_panel_disable).

> +}
> +
> +static void tc_bridge_post_disable(struct drm_bridge *bridge)
> +{
> +	struct tc_data *tc = bridge_to_tc(bridge);
> +
> +	drm_panel_unprepare(tc->panel);
> +}
> +
> +#ifdef TC358775_DEBUG
> +static u32 d2l_read(struct tc_data *tc, u16 reg)
> +{
> +	int ret;
> +	u32 data;
> +
> +	ret = regmap_bulk_read(tc->regmap, reg, &data, 1);
> +	if (ret)
> +		return ret;
> +
> +	pr_debug("d2l: I2C : reg:%04x value:%08x\n", reg, data);
> +
> +	return data;
> +}
> +#endif


I guess this leftover can be removed as well.


> +
> +static int d2l_write(struct tc_data *tc, u16 reg, u32 data)
> +{
> +	int ret = 0;
> +
> +	ret = regmap_bulk_write(tc->regmap, reg, (u32[]) {data}, 1);
> +
> +#ifdef TC358775_DEBUG
> +	d2l_read(tc, reg);
> +#endif
> +	return ret;
> +}
> +
> +static void tc_bridge_enable(struct drm_bridge *bridge)
> +{
> +	struct tc_data *tc = bridge_to_tc(bridge);
> +	int ret;
> +	u32 hbpr, hpw, htime1, hfpr, hsize, htime2;
> +	u32 vbpr, vpw, vtime1, vfpr, vsize, vtime2;
> +	u32 val = 0;
> +	struct drm_display_mode *mode;
> +
> +	mode = &bridge->encoder->crtc->state->adjusted_mode;
> +
> +	hbpr = 0;
> +	hpw  = mode->hsync_end - mode->hsync_start;
> +	vbpr = 0;
> +	vpw  = mode->vsync_end - mode->vsync_start;
> +
> +	htime1 = (hbpr << 16) + hpw;
> +	vtime1 = (vbpr << 16) + vpw;
> +
> +	hfpr = mode->hsync_start - mode->hdisplay;
> +	hsize = mode->hdisplay;
> +	vfpr = mode->vsync_start - mode->vdisplay;
> +	vsize = mode->vdisplay;
> +
> +	htime2 = (hfpr << 16) + hsize;
> +	vtime2 = (vfpr << 16) + vsize;
> +
> +	ret = regmap_read(tc->regmap, IDREG, &tc->rev);
> +	if (ret) {
> +		dev_err(tc->dev, "can not read device ID: %d\n", ret);
> +		return;
> +	}
> +	pr_debug("tc IDREG %04x Rev. %08x\n", IDREG, tc->rev);
> +
> +	d2l_write(tc, SYSRST, 0x000000FF);
> +	mdelay(30);
> +
> +	ret = regmap_register_patch(tc->regmap,
> +				    tc_fixed_registers,
> +				    ARRAY_SIZE(tc_fixed_registers));
> +	if (ret)
> +		return;
> +
> +	val = ((L0EN << tc->num_dsi_lanes) - L0EN) | DSI_CLEN_BIT;
> +	d2l_write(tc, PPI_LANEENABLE, val);
> +	d2l_write(tc, DSI_LANEENABLE, val);
> +
> +	d2l_write(tc, PPI_STARTPPI, 0x00000001);
> +	d2l_write(tc, DSI_STARTDSI, 0x00000001);
> +
> +	val = TC358775_VPCTRL_VSDELAY(21); //TODO : to set the dynamic value
> +
> +	if (tc->connector.display_info.bpc == 8) {/* RGB888 */
> +		val |= TC358775_VPCTRL_OPXLFMT(1);
> +		d2l_write(tc, VPCTRL, val);
> +	} else {				/* RGB666 */
> +		val |= TC358775_VPCTRL_MSF(1);
> +		d2l_write(tc, VPCTRL, val);
> +	}
> +
> +	d2l_write(tc, HTIM1, htime1);
> +	d2l_write(tc, VTIM1, vtime1);
> +	d2l_write(tc, HTIM2, htime2);
> +	d2l_write(tc, VTIM2, vtime2);
> +
> +	d2l_write(tc, VFUEN, 0x00000001);
> +	d2l_write(tc, SYSRST, 0x00000004);
> +	d2l_write(tc, LVPHY0, 0x00040006);
> +
> +	if (tc->data_format) { /* Data Format VESA=0 , JEIDA=1 */
> +		ret = regmap_register_patch
> +			(tc->regmap,
> +			 tc_vesa_data_format_registers,
> +			 ARRAY_SIZE(tc_vesa_data_format_registers));
> +		if (ret)
> +			return;
> +	}
> +
> +	d2l_write(tc, VFUEN, 0x00000001);
> +
> +	val = TC358775_LVCFG_PCLKDIV(DIVIDE_BY_3) | LVCFG_LVEN_BIT;
> +	if (tc->dual_link)
> +		val |= TC358775_LVCFG_LVDLINK(1);
> +
> +	d2l_write(tc, LVCFG, val);
> +
> +	drm_panel_enable(tc->panel);
> +}
> +
> +static int tc_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct tc_data *tc = connector_to_tc(connector);
> +	struct edid *edid;
> +	unsigned int count;
> +
> +	if (tc->panel && tc->panel->funcs && tc->panel->funcs->get_modes) {
> +		count = tc->panel->funcs->get_modes(tc->panel, connector);
> +		if (count > 0)
> +			return count;
> +	}
> +
> +	edid = drm_get_edid(connector, tc->i2c->adapter);
> +	if (!edid)
> +		return 0;
> +
> +	drm_connector_update_edid_property(connector, edid);
> +	count = drm_add_edid_modes(connector, edid);
> +	kfree(edid);
> +
> +	return count;
> +}
> +
> +static int tc_connector_mode_valid(struct drm_connector *connector,
> +				   struct drm_display_mode *mode)
> +{
> +	struct tc_data *tc = connector_to_tc(connector);
> +
> +	/* Maximum pixel clock speed 135MHz-single-link/270MHz-dual-link */
> +	if ((mode->clock > 135000 && tc->dual_link == 0) ||
> +	    (mode->clock > 270000 && tc->dual_link == 1))
> +		return MODE_CLOCK_HIGH;
> +
> +	return MODE_OK;
> +}
> +
> +static struct drm_encoder *
> +tc_connector_best_encoder(struct drm_connector *connector)
> +{
> +	struct tc_data *tc = connector_to_tc(connector);
> +
> +	return tc->bridge.encoder;
> +}
> +
> +static const struct drm_connector_helper_funcs tc_connector_helper_funcs = {
> +	.get_modes = tc_connector_get_modes,
> +	.mode_valid = tc_connector_mode_valid,
> +	.best_encoder = tc_connector_best_encoder,
> +};
> +
> +static const struct drm_connector_funcs tc_connector_funcs = {
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = drm_connector_cleanup,
> +	.reset = drm_atomic_helper_connector_reset,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +int tc358775_parse_dt(struct device_node *np, struct tc_data *tc)
> +{
> +	u32 num_lanes;
> +	u8 dual_link, data_format;
> +
> +	of_property_read_u8(np, "tc,dual-link", &dual_link);
> +	of_property_read_u8(np, "tc,data-format", &data_format);
> +	of_property_read_u32(np, "tc,dsi-lanes", &num_lanes);
> +
> +	if (num_lanes < 1 || num_lanes > 4)
> +		return -EINVAL;
> +
> +	tc->num_dsi_lanes = num_lanes;
> +	tc->dual_link = dual_link;
> +	tc->data_format = data_format;
> +
> +	tc->host_node = of_graph_get_remote_node(np, 0, 0);
> +	if (!tc->host_node)
> +		return -ENODEV;
> +
> +	of_node_put(tc->host_node);
> +
> +	return 0;
> +}
> +
> +int tc358775_attach_dsi(struct tc_data *tc)
> +{
> +	struct device *dev = &tc->i2c->dev;
> +	struct mipi_dsi_host *host;
> +	struct mipi_dsi_device *dsi;
> +	int ret = 0;
> +	const struct mipi_dsi_device_info info = { .type = "tc358775",
> +							.channel = 0,
> +							.node = NULL,
> +						};
> +
> +	host = of_find_mipi_dsi_host_by_node(tc->host_node);
> +	if (!host) {
> +		dev_err(dev, "failed to find dsi host\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	dsi = mipi_dsi_device_register_full(host, &info);
> +	if (IS_ERR(dsi)) {
> +		dev_err(dev, "failed to create dsi device\n");
> +		ret = PTR_ERR(dsi);
> +		goto err_dsi_device;
> +	}
> +
> +	tc->dsi = dsi;
> +
> +	dsi->lanes = tc->num_dsi_lanes;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to attach dsi to host\n");
> +		goto err_dsi_attach;
> +	}
> +
> +	return 0;
> +
> +err_dsi_attach:
> +	mipi_dsi_device_unregister(dsi);
> +err_dsi_device:
> +	return ret;
> +}
> +
> +static int tc_bridge_attach(struct drm_bridge *bridge)
> +{
> +	struct tc_data *tc = bridge_to_tc(bridge);
> +	struct drm_device *drm = bridge->dev;
> +	int ret;
> +
> +	/* Create LVDS connector */
> +	drm_connector_helper_add(&tc->connector, &tc_connector_helper_funcs);
> +	ret = drm_connector_init(drm, &tc->connector, &tc_connector_funcs,
> +				 DRM_MODE_CONNECTOR_LVDS);
> +	if (ret)
> +		return ret;
> +
> +	if (tc->panel)
> +		drm_panel_attach(tc->panel, &tc->connector);
> +
> +	drm_connector_attach_encoder(&tc->connector, tc->bridge.encoder);
> +
> +	ret = tc358775_attach_dsi(tc);


Ignored retval.


> +
> +	return 0;
> +}
> +
> +static const struct drm_bridge_funcs tc_bridge_funcs = {
> +	.attach = tc_bridge_attach,
> +	.pre_enable = tc_bridge_pre_enable,
> +	.enable = tc_bridge_enable,
> +	.disable = tc_bridge_disable,
> +	.post_disable = tc_bridge_post_disable,
> +};
> +
> +static const struct regmap_config tc_regmap_config = {
> +	.name = "tc358775",
> +	.reg_bits = 16,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +	.max_register = 0x05A8,
> +	.cache_type = REGCACHE_RBTREE,
> +	.reg_format_endian = REGMAP_ENDIAN_BIG,
> +	.val_format_endian = REGMAP_ENDIAN_LITTLE,
> +};
> +
> +static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct tc_data *tc;
> +	int ret;
> +	unsigned int i;
> +
> +	tc = devm_kzalloc(dev, sizeof(*tc), GFP_KERNEL);
> +	if (!tc)
> +		return -ENOMEM;
> +
> +	tc->dev = dev;
> +	tc->i2c = client;
> +	tc->status = connector_status_connected;
> +
> +	/* port@1 is the output port */
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &tc->panel, NULL);
> +	if (ret && ret != -ENODEV)
> +		return ret;
> +
> +	ret = tc358775_parse_dt(dev->of_node, tc);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(tc->supplies); i++)
> +		tc->supplies[i].supply = regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(tc->supplies),
> +				      tc->supplies);
> +	if (ret < 0)
> +		dev_err(dev, "failed to init regulator, ret=%d\n", ret);
> +
> +	tc->stby_gpio = devm_gpiod_get(dev, "stby", GPIOD_OUT_HIGH);
> +	if (IS_ERR(tc->stby_gpio)) {
> +		ret = PTR_ERR(tc->stby_gpio);
> +		dev_err(dev, "cannot get stby-gpio %d\n", ret);
> +		return ret;
> +	}
> +
> +	tc->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> +	if (IS_ERR(tc->reset_gpio)) {
> +		ret = PTR_ERR(tc->reset_gpio);
> +		dev_err(dev, "cannot get reset-gpios %d\n", ret);
> +		return ret;
> +	}
> +
> +	tc->regmap = devm_regmap_init_i2c(client, &tc_regmap_config);
> +	if (IS_ERR(tc->regmap)) {
> +		ret = PTR_ERR(tc->regmap);
> +		dev_err(dev, "Failed to initialize regmap: %d\n", ret);
> +		return ret;
> +	}
> +
> +	tc->bridge.funcs = &tc_bridge_funcs;
> +	tc->bridge.of_node = dev->of_node;
> +	drm_bridge_add(&tc->bridge);
> +
> +	i2c_set_clientdata(client, tc);
> +
> +	return 0;
> +}
> +
> +static int tc_remove(struct i2c_client *client)
> +{
> +	struct tc_data *tc = i2c_get_clientdata(client);
> +
> +	drm_bridge_remove(&tc->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id tc358775_i2c_ids[] = {
> +	{ "tc358775", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, tc358775_i2c_ids);
> +
> +static const struct of_device_id tc358775_of_ids[] = {
> +	{ .compatible = "toshiba,tc358775", },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, tc358775_of_ids);
> +
> +static struct i2c_driver tc358775_driver = {
> +	.driver = {
> +		.name = "tc358775",
> +		.of_match_table = tc358775_of_ids,
> +	},
> +	.id_table = tc358775_i2c_ids,
> +	.probe = tc_probe,
> +	.remove	= tc_remove,
> +};
> +module_i2c_driver(tc358775_driver);
> +
> +MODULE_AUTHOR("Vinay Simha BN <vinaysimha@inforcecomputing.com>");
> +MODULE_DESCRIPTION("tc358775 LVDS encoder driver");


maybe  better:

tc358775 DSI/LVDS bridge driver


Regards
Andrzej

> +MODULE_LICENSE("GPL v2");