Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH v3 7/9] drm/bridge: tc358764: Add DSI to LVDS bridge
 driver
To:     Maciej Purski <m.purski@samsung.com>, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
        dri-devel@lists.freedesktop.org
Cc:     David Airlie <airlied@linux.ie>, Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Kukjin Kim <kgene@kernel.org>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Archit Taneja <architt@codeaurora.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Inki Dae <inki.dae@samsung.com>,
        Joonyoung Shim <jy0922.shim@samsung.com>,
        Seung-Woo Kim <sw0312.kim@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
From:   Andrzej Hajda <a.hajda@samsung.com>
Date:   Mon, 9 Jul 2018 16:08:58 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
        Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <1529396370-18761-8-git-send-email-m.purski@samsung.com>
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Message-Id: <20180709140900eucas1p1420203570c5cf82320f0313c64777d63~-uJM1AEu92685626856eucas1p1L@eucas1p1.samsung.com>
Content-Type: text/plain; charset="utf-8"
CMS-TYPE: 201P
References: <1529396370-18761-1-git-send-email-m.purski@samsung.com>
        <CGME20180619082002eucas1p2e3606dff0191ab5380cc455e33083459@eucas1p2.samsung.com>
        <1529396370-18761-8-git-send-email-m.purski@samsung.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 19.06.2018 10:19, Maciej Purski wrote:
> From: Andrzej Hajda <a.hajda@samsung.com>
>
> Add a drm_bridge driver for the Toshiba TC358764 DSI to LVDS bridge.
>
> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
> Signed-off-by: Maciej Purski <m.purski@samsung.com>
> ---
>  drivers/gpu/drm/bridge/Kconfig    |   8 +
>  drivers/gpu/drm/bridge/Makefile   |   1 +
>  drivers/gpu/drm/bridge/tc358764.c | 521 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 530 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/tc358764.c
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index fa2c799..f3da8a7 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -110,6 +110,14 @@ config DRM_THINE_THC63LVD1024
>  	---help---
>  	  Thine THC63LVD1024 LVDS/parallel converter driver.
>  
> +config DRM_TOSHIBA_TC358764
> +	tristate "TC358764 DSI/LVDS bridge"
> +	depends on DRM && DRM_PANEL
> +	depends on OF
> +	select DRM_MIPI_DSI
> +	help
> +	  Toshiba TC358764 DSI/LVDS bridge driver.
> +
>  config DRM_TOSHIBA_TC358767
>  	tristate "Toshiba TC358767 eDP bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index 35f88d4..bf7c0ce 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_DRM_SIL_SII8620) += sil-sii8620.o
>  obj-$(CONFIG_DRM_SII902X) += sii902x.o
>  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-$(CONFIG_DRM_ANALOGIX_DP) += analogix/
>  obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
> diff --git a/drivers/gpu/drm/bridge/tc358764.c b/drivers/gpu/drm/bridge/tc358764.c
> new file mode 100644
> index 0000000..0aee155
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/tc358764.c
> @@ -0,0 +1,521 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2018 Samsung Electronics Co., Ltd
> + *
> + * Authors:
> + *	Andrzej Hajda <a.hajda@samsung.com>
> + *	Maciej Purski <m.purski@samsung.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * 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 should have received a copy of the GNU General Public License
> + * along with this program.

You should drop license blob if SPDX identifer provided, see for example
drivers/gpu/drm/i915/intel_hdcp.c

> + *
> + */
> +
> +#include <drm/drm_atomic_helper.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_crtc_helper.h>
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <video/mipi_display.h>

You can order it alphabetically.

> +
> +#define FLD_MASK(start, end)    (((1 << ((start) - (end) + 1)) - 1) << (end))
> +#define FLD_VAL(val, start, end) (((val) << (end)) & FLD_MASK(start, end))
> +
> +/* PPI layer registers */
> +#define PPI_STARTPPI		0x0104 /* START control bit */
> +#define PPI_LPTXTIMECNT		0x0114 /* LPTX timing signal */
> +#define PPI_LANEENABLE		0x0134 /* Enables each lane */
> +#define PPI_TX_RX_TA		0x013C /* BTA timing parameters */
> +#define PPI_D0S_CLRSIPOCOUNT	0x0164 /* Assertion timer for Lane 0 */
> +#define PPI_D1S_CLRSIPOCOUNT	0x0168 /* Assertion timer for Lane 1 */
> +#define PPI_D2S_CLRSIPOCOUNT	0x016C /* Assertion timer for Lane 2 */
> +#define PPI_D3S_CLRSIPOCOUNT	0x0170 /* Assertion timer for Lane 3 */
> +#define PPI_START_FUNCTION	1
> +
> +/* DSI layer registers */
> +#define DSI_STARTDSI		0x0204 /* START control bit of DSI-TX */
> +#define DSI_LANEENABLE		0x0210 /* Enables each lane */
> +#define DSI_RX_START		1
> +
> +/* Video path registers */
> +#define VP_CTRL			0x0450 /* Video Path Control */
> +#define VP_CTRL_MSF(v)		FLD_VAL(v, 0, 0) /* Magic square in RGB666 */
> +#define VP_CTRL_VTGEN(v)	FLD_VAL(v, 4, 4) /* Use chip clock for timing */
> +#define VP_CTRL_EVTMODE(v)	FLD_VAL(v, 5, 5) /* Event mode */
> +#define VP_CTRL_RGB888(v)	FLD_VAL(v, 8, 8) /* RGB888 mode */
> +#define VP_CTRL_VSDELAY(v)	FLD_VAL(v, 31, 20) /* VSYNC delay */
> +#define VP_CTRL_HSPOL		BIT(17) /* Polarity of HSYNC signal */
> +#define VP_CTRL_DEPOL		BIT(18) /* Polarity of DE signal */
> +#define VP_CTRL_VSPOL		BIT(19) /* Polarity of VSYNC signal */
> +#define VP_HTIM1		0x0454 /* Horizontal Timing Control 1 */
> +#define VP_HTIM1_HBP(v)		FLD_VAL(v, 24, 16)
> +#define VP_HTIM1_HSYNC(v)	FLD_VAL(v, 8, 0)
> +#define VP_HTIM2		0x0458 /* Horizontal Timing Control 2 */
> +#define VP_HTIM2_HFP(v)		FLD_VAL(v, 24, 16)
> +#define VP_HTIM2_HACT(v)	FLD_VAL(v, 10, 0)
> +#define VP_VTIM1		0x045C /* Vertical Timing Control 1 */
> +#define VP_VTIM1_VBP(v)		FLD_VAL(v, 23, 16)
> +#define VP_VTIM1_VSYNC(v)	FLD_VAL(v, 7, 0)
> +#define VP_VTIM2		0x0460 /* Vertical Timing Control 2 */
> +#define VP_VTIM2_VFP(v)		FLD_VAL(v, 23, 16)
> +#define VP_VTIM2_VACT(v)	FLD_VAL(v, 10, 0)
> +#define VP_VFUEN		0x0464 /* Video Frame Timing Update Enable */
> +
> +/* LVDS registers */
> +#define LV_MX0003		0x0480 /* Mux input bit 0 to 3 */
> +#define LV_MX0407		0x0484 /* Mux input bit 4 to 7 */
> +#define LV_MX0811		0x0488 /* Mux input bit 8 to 11 */
> +#define LV_MX1215		0x048C /* Mux input bit 12 to 15 */
> +#define LV_MX1619		0x0490 /* Mux input bit 16 to 19 */
> +#define LV_MX2023		0x0494 /* Mux input bit 20 to 23 */
> +#define LV_MX2427		0x0498 /* Mux input bit 24 to 27 */
> +#define LV_MX(b0, b1, b2, b3)	(FLD_VAL(b0, 4, 0) | FLD_VAL(b1, 12, 8) | \
> +				FLD_VAL(b2, 20, 16) | FLD_VAL(b3, 28, 24))
> +
> +/* Input bit numbers used in mux registers */
> +enum {
> +	LVI_R0,
> +	LVI_R1,
> +	LVI_R2,
> +	LVI_R3,
> +	LVI_R4,
> +	LVI_R5,
> +	LVI_R6,
> +	LVI_R7,
> +	LVI_G0,
> +	LVI_G1,
> +	LVI_G2,
> +	LVI_G3,
> +	LVI_G4,
> +	LVI_G5,
> +	LVI_G6,
> +	LVI_G7,
> +	LVI_B0,
> +	LVI_B1,
> +	LVI_B2,
> +	LVI_B3,
> +	LVI_B4,
> +	LVI_B5,
> +	LVI_B6,
> +	LVI_B7,
> +	LVI_HS,
> +	LVI_VS,
> +	LVI_DE,
> +	LVI_L0
> +};
> +
> +#define LV_CFG			0x049C /* LVDS Configuration */
> +#define LV_PHY0			0x04A0 /* LVDS PHY 0 */
> +#define LV_PHY0_RST(v)		FLD_VAL(v, 22, 22) /* PHY reset */
> +#define LV_PHY0_IS(v)		FLD_VAL(v, 15, 14)
> +#define LV_PHY0_ND(v)		FLD_VAL(v, 4, 0) /* Frequency range select */
> +#define LV_PHY0_PRBS_ON(v)	FLD_VAL(v, 20, 16) /* Clock/Data Flag pins */
> +
> +/* System registers */
> +#define SYS_RST			0x0504 /* System Reset */
> +#define SYS_ID			0x0580 /* System ID */
> +
> +#define SYS_RST_I2CS		BIT(0) /* Reset I2C-Slave controller */
> +#define SYS_RST_I2CM		BIT(1) /* Reset I2C-Master controller */
> +#define SYS_RST_LCD		BIT(2) /* Reset LCD controller */
> +#define SYS_RST_BM		BIT(3) /* Reset Bus Management controller */
> +#define SYS_RST_DSIRX		BIT(4) /* Reset DSI-RX and App controller */
> +#define SYS_RST_REG		BIT(5) /* Reset Register module */
> +
> +#define LPX_PERIOD		2
> +#define TTA_SURE		3
> +#define TTA_GET			0x20000
> +
> +/* Lane enable PPI and DSI register bits */
> +#define LANEENABLE_CLEN		BIT(0)
> +#define LANEENABLE_L0EN		BIT(1)
> +#define LANEENABLE_L1EN		BIT(2)
> +#define LANEENABLE_L2EN		BIT(3)
> +#define LANEENABLE_L3EN		BIT(4)
> +
> +/* LVCFG fields */
> +#define LV_CFG_LVEN		BIT(0)
> +#define LV_CFG_LVDLINK		BIT(1)
> +#define LV_CFG_CLKPOL1		BIT(2)
> +#define LV_CFG_CLKPOL2		BIT(3)
> +
> +static const char * const tc358764_supplies[] = {
> +	"vddc", "vddio", "vddmipi", "vddlvds133", "vddlvds112"
> +};
> +
> +struct tc358764 {
> +	struct device *dev;
> +	struct drm_bridge bridge;
> +	struct drm_connector connector;
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(tc358764_supplies)];
> +	struct gpio_desc *gpio_reset;
> +
> +	struct drm_panel *panel;
> +};
> +
> +static int tc358764_read(struct tc358764 *ctx, u16 addr, u32 *val)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	ssize_t ret;
> +
> +	cpu_to_le16s(&addr);
> +	ret = mipi_dsi_generic_read(dsi, &addr, sizeof(addr), val, sizeof(val));

As robot complained it should be sizeof(*val).
> +	if (ret >= 0)
> +		le32_to_cpus(val);
> +
> +	dev_dbg(ctx->dev, "read: %d, addr: %d\n", addr, *val);
> +
> +	return ret;
> +}
> +
> +static int tc358764_write(struct tc358764 *ctx, u16 addr, u32 val)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	ssize_t ret;
> +	u8 data[6];
> +
> +	data[0] = addr;
> +	data[1] = addr >> 8;
> +	data[2] = val;
> +	data[3] = val >> 8;
> +	data[4] = val >> 16;
> +	data[5] = val >> 24;
> +
> +	ret = mipi_dsi_generic_write(dsi, data, sizeof(data));
> +
> +	return ret;
> +}
> +
> +static inline struct tc358764 *bridge_to_tc358764(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct tc358764, bridge);
> +}
> +
> +static inline
> +struct tc358764 *connector_to_tc358764(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct tc358764, connector);
> +}
> +
> +static int tc358764_init(struct tc358764 *ctx)
> +{
> +	u32 v = 0;
> +
> +	tc358764_read(ctx, SYS_ID, &v);

There is no error handling, here and below.

> +	dev_info(ctx->dev, "ID: %#x\n", v);
> +
> +	/* configure PPI counters */
> +	tc358764_write(ctx, PPI_TX_RX_TA, TTA_GET | TTA_SURE);
> +	tc358764_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
> +	tc358764_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
> +	tc358764_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
> +	tc358764_write(ctx, PPI_D2S_CLRSIPOCOUNT, 5);
> +	tc358764_write(ctx, PPI_D3S_CLRSIPOCOUNT, 5);
> +
> +	/* enable four data lanes and clock lane */
> +	tc358764_write(ctx, PPI_LANEENABLE, LANEENABLE_L3EN | LANEENABLE_L2EN |
> +		       LANEENABLE_L1EN | LANEENABLE_L0EN | LANEENABLE_CLEN);
> +	tc358764_write(ctx, DSI_LANEENABLE, LANEENABLE_L3EN | LANEENABLE_L2EN |
> +		       LANEENABLE_L1EN | LANEENABLE_L0EN | LANEENABLE_CLEN);
> +
> +	/* start */
> +	tc358764_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
> +	tc358764_write(ctx, DSI_STARTDSI, DSI_RX_START);
> +
> +	/* configure video path */
> +	tc358764_write(ctx, VP_CTRL, VP_CTRL_VSDELAY(15) | VP_CTRL_RGB888(1) |
> +		       VP_CTRL_EVTMODE(1) | VP_CTRL_HSPOL | VP_CTRL_VSPOL);
> +
> +	/* reset PHY */
> +	tc358764_write(ctx, LV_PHY0, LV_PHY0_RST(1) |
> +		       LV_PHY0_PRBS_ON(4) | LV_PHY0_IS(2) | LV_PHY0_ND(6));
> +	tc358764_write(ctx, LV_PHY0, LV_PHY0_PRBS_ON(4) | LV_PHY0_IS(2) |
> +		       LV_PHY0_ND(6));
> +
> +	/* reset bridge */
> +	tc358764_write(ctx, SYS_RST, SYS_RST_LCD);
> +
> +	/* set bit order */
> +	tc358764_write(ctx, LV_MX0003, LV_MX(LVI_R0, LVI_R1, LVI_R2, LVI_R3));
> +	tc358764_write(ctx, LV_MX0407, LV_MX(LVI_R4, LVI_R7, LVI_R5, LVI_G0));
> +	tc358764_write(ctx, LV_MX0811, LV_MX(LVI_G1, LVI_G2, LVI_G6, LVI_G7));
> +	tc358764_write(ctx, LV_MX1215, LV_MX(LVI_G3, LVI_G4, LVI_G5, LVI_B0));
> +	tc358764_write(ctx, LV_MX1619, LV_MX(LVI_B6, LVI_B7, LVI_B1, LVI_B2));
> +	tc358764_write(ctx, LV_MX2023, LV_MX(LVI_B3, LVI_B4, LVI_B5, LVI_L0));
> +	tc358764_write(ctx, LV_MX2427, LV_MX(LVI_HS, LVI_VS, LVI_DE, LVI_R6));
> +	tc358764_write(ctx, LV_CFG, LV_CFG_CLKPOL2 | LV_CFG_CLKPOL1 |
> +		       LV_CFG_LVEN);
> +
> +	return 0;
> +}
> +
> +static void tc358764_reset(struct tc358764 *ctx)
> +{
> +	msleep(20);
> +	gpiod_set_value(ctx->gpio_reset, 0);
> +	msleep(20);
> +	gpiod_set_value(ctx->gpio_reset, 1);
> +	msleep(40);
> +}
> +
> +static void tc358764_poweroff(struct tc358764 *ctx)
> +{
> +	int ret;
> +
> +	tc358764_reset(ctx);
> +
> +	drm_panel_disable(ctx->panel);
I do not see drm_panel_unprepare, it should be called from post_disable
callback.
> +	msleep(40);
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
> +}
> +
> +static int tc358764_get_modes(struct drm_connector *connector)
> +{
> +	struct tc358764 *ctx = connector_to_tc358764(connector);
> +
> +	if (ctx->panel && ctx->panel->funcs && ctx->panel->funcs->get_modes)
> +		return ctx->panel->funcs->get_modes(ctx->panel);

drm_panel_get_modes

> +
> +	return 0;
> +}
> +
> +static const
> +struct drm_connector_helper_funcs tc358764_connector_helper_funcs = {
> +	.get_modes = tc358764_get_modes,
> +};
> +
> +static const struct drm_connector_funcs tc358764_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,
> +};
> +
> +static void tc358764_disable(struct drm_bridge *bridge)
> +{
> +	struct tc358764 *ctx = bridge_to_tc358764(bridge);
> +
> +	tc358764_poweroff(ctx);
> +}
> +
> +static void tc358764_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct tc358764 *ctx = bridge_to_tc358764(bridge);
> +	int ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies),
> +					ctx->supplies);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
> +
> +	tc358764_reset(ctx);
> +	tc358764_init(ctx);
> +}
> +
> +static void tc358764_enable(struct drm_bridge *bridge)
> +{
> +	struct tc358764 *ctx = bridge_to_tc358764(bridge);
> +	int ret;
> +
> +	drm_panel_prepare(ctx->panel);

drm_panel_prepare should be called from pre_enable.

> +
> +	ret = drm_panel_enable(ctx->panel);
> +	if (ret < 0)
> +		pr_err("panel enable failed\n");
> +
> +	msleep(40);
> +}
> +
> +static int tc358764_attach(struct drm_bridge *bridge)
> +{
> +	struct tc358764 *ctx = bridge_to_tc358764(bridge);
> +	struct drm_device *drm = bridge->dev;
> +	int ret;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Encoder not found\n");
> +		return -ENODEV;
> +	}
> +
> +	ctx->connector.polled = DRM_CONNECTOR_POLL_HPD;
> +	ret = drm_connector_init(drm, &ctx->connector,
> +				 &tc358764_connector_funcs,
> +				 DRM_MODE_CONNECTOR_LVDS);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	drm_connector_helper_add(&ctx->connector,
> +				 &tc358764_connector_helper_funcs);
> +
> +	drm_mode_connector_attach_encoder(&ctx->connector, bridge->encoder);
> +
> +	if (ctx->panel)
> +		drm_panel_attach(ctx->panel, &ctx->connector);
Could ctx->panel be NULL here?
> +
> +	drm_atomic_helper_connector_reset(&ctx->connector);
> +	drm_connector_register(&ctx->connector);
> +
> +	return 0;
> +}
> +
> +static const struct drm_bridge_funcs tc358764_bridge_funcs = {
> +	.disable = tc358764_disable,
> +	.enable = tc358764_enable,
> +	.pre_enable = tc358764_pre_enable,
> +	.attach = tc358764_attach,
> +};
> +
> +static struct device_node *tc358764_of_find_panel_node(struct device *dev)
> +{
> +	struct device_node *np, *ep;
> +
> +	ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
> +	if (!ep) {
> +		pr_err("failed to get endpoint\n");
> +		return NULL;
> +	}
> +
> +	np = of_graph_get_remote_port_parent(ep);
> +
> +	return np;
> +}

There is already helper for it.


> +
> +static int tc358764_parse_dt(struct tc358764 *ctx)
> +{
> +	struct device *dev = ctx->dev;
> +	struct device_node *np = dev->of_node;
> +	struct device_node *lvds;
> +
> +	ctx->gpio_reset = devm_gpiod_get_from_of_node(dev, np, "reset", 0,
> +						      GPIOD_OUT_LOW,
> +						      "tc358764-reset");
> +	if (IS_ERR(ctx->gpio_reset)) {
> +		dev_err(dev, "no reset GPIO pin provided\n");
> +		return PTR_ERR(ctx->gpio_reset);
> +	}
> +
> +	lvds = tc358764_of_find_panel_node(ctx->dev);
> +	if (!lvds) {
> +		dev_err(dev, "cannot find panel node\n");
> +		return -EINVAL;
> +	}
> +
> +	ctx->panel = of_drm_find_panel(lvds);

Or even for it: drm_of_find_panel_or_bridge.

> +	if (!ctx->panel) {
> +		dev_err(dev, "panel not registered\n");
> +		return -EPROBE_DEFER;
> +	}
> +
> +	return 0;
> +}
> +
> +static int tc358764_configure_regulators(struct tc358764 *ctx)
> +{
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); ++i)
> +		ctx->supplies[i].supply = tc358764_supplies[i];
> +
> +	ret = devm_regulator_bulk_get(ctx->dev, ARRAY_SIZE(ctx->supplies),
> +				      ctx->supplies);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "failed to get regulators: %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int tc358764_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	struct tc358764 *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(struct tc358764), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	ctx->dev = dev;
> +
> +	dsi->lanes = 4;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST
> +		| MIPI_DSI_MODE_VIDEO_AUTO_VERT | MIPI_DSI_MODE_LPM;
> +
> +	ret = tc358764_parse_dt(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = tc358764_configure_regulators(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->bridge.funcs = &tc358764_bridge_funcs;
> +	ctx->bridge.of_node = dev->of_node;
> +
> +	drm_bridge_add(&ctx->bridge);
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		drm_bridge_remove(&ctx->bridge);
> +		dev_err(dev, "failed to attach dsi\n");
> +	}
> +
> +	return ret;
> +}
> +
> +static int tc358764_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct tc358764 *ctx = mipi_dsi_get_drvdata(dsi);
> +
> +	tc358764_poweroff(ctx);

It should be dropped, dsi host will do it properly if neccesary from the
call below.

Regards
Andrzej

> +
> +	mipi_dsi_detach(dsi);
> +	drm_bridge_remove(&ctx->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id tc358764_of_match[] = {
> +	{ .compatible = "toshiba,tc358764" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, tc358764_of_match);
> +
> +static struct mipi_dsi_driver tc358764_driver = {
> +	.probe = tc358764_probe,
> +	.remove = tc358764_remove,
> +	.driver = {
> +		.name = "tc358764",
> +		.owner = THIS_MODULE,
> +		.of_match_table = tc358764_of_match,
> +	},
> +};
> +module_mipi_dsi_driver(tc358764_driver);
> +
> +MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
> +MODULE_AUTHOR("Maciej Purski <m.purski@samsung.com>");
> +MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358764 DSI/LVDS Bridge");
> +MODULE_LICENSE("GPL v2");