Re: [PATCH V3 2/2] drm/bridge: tc358762: Add basic driver for Toshiba TC358762 DSI-to-DPI bridge

[Sam Ravnborg <sam@ravnborg.org>]

Hi Marek.

On Sun, Aug 09, 2020 at 12:57:05PM +0200, Marek Vasut wrote:
> Add very basic driver for Toshiba TC358762 DSI-to-DPI bridge, derived
> from tc358764 driver and panel-raspberrypi-touchscreen. This driver is
> meant to replace the panel-raspberrypi-touchscreen too, as the bridge
> connection can be described in DT too.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> To: dri-devel@lists.freedesktop.org
> Cc: Eric Anholt <eric@anholt.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: devicetree@vger.kernel.org
> Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> ---
> V2: Switch to DRM_PANEL_BRIDGE
> V3: No change

Applied to drm-misc-next.

	Sam

> ---
>  drivers/gpu/drm/bridge/Kconfig    |   8 +
>  drivers/gpu/drm/bridge/Makefile   |   1 +
>  drivers/gpu/drm/bridge/tc358762.c | 280 ++++++++++++++++++++++++++++++
>  3 files changed, 289 insertions(+)
>  create mode 100644 drivers/gpu/drm/bridge/tc358762.c
> 
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 43271c21d3fc..58e879852082 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -153,6 +153,14 @@ config DRM_THINE_THC63LVD1024
>  	help
>  	  Thine THC63LVD1024 LVDS/parallel converter driver.
>  
> +config DRM_TOSHIBA_TC358762
> +	tristate "TC358762 DSI/DPI bridge"
> +	depends on OF
> +	select DRM_MIPI_DSI
> +	select DRM_PANEL_BRIDGE
> +	help
> +	  Toshiba TC358762 DSI/DPI bridge driver.
> +
>  config DRM_TOSHIBA_TC358764
>  	tristate "TC358764 DSI/LVDS bridge"
>  	depends on OF
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index d63d4b7e4347..b341c60ee96a 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_SII902X) += sii902x.o
>  obj-$(CONFIG_DRM_SII9234) += sii9234.o
>  obj-$(CONFIG_DRM_SIMPLE_BRIDGE) += simple-bridge.o
>  obj-$(CONFIG_DRM_THINE_THC63LVD1024) += thc63lvd1024.o
> +obj-$(CONFIG_DRM_TOSHIBA_TC358762) += tc358762.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358764) += tc358764.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
>  obj-$(CONFIG_DRM_TOSHIBA_TC358768) += tc358768.o
> diff --git a/drivers/gpu/drm/bridge/tc358762.c b/drivers/gpu/drm/bridge/tc358762.c
> new file mode 100644
> index 000000000000..1bfdfc6affaf
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/tc358762.c
> @@ -0,0 +1,280 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Marek Vasut <marex@denx.de>
> + *
> + * Based on tc358764.c by
> + *  Andrzej Hajda <a.hajda@samsung.com>
> + *  Maciej Purski <m.purski@samsung.com>
> + *
> + * Based on rpi_touchscreen.c by
> + *  Eric Anholt <eric@anholt.net>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/of_graph.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <video/mipi_display.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_fb_helper.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_of.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
> +#include <drm/drm_probe_helper.h>
> +
> +/* PPI layer registers */
> +#define PPI_STARTPPI		0x0104 /* START control bit */
> +#define PPI_LPTXTIMECNT		0x0114 /* LPTX timing signal */
> +#define PPI_D0S_ATMR		0x0144
> +#define PPI_D1S_ATMR		0x0148
> +#define PPI_D0S_CLRSIPOCOUNT	0x0164 /* Assertion timer for Lane 0 */
> +#define PPI_D1S_CLRSIPOCOUNT	0x0168 /* Assertion timer for Lane 1 */
> +#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
> +
> +/* LCDC/DPI Host Registers */
> +#define LCDCTRL			0x0420
> +
> +/* SPI Master Registers */
> +#define SPICMR			0x0450
> +#define SPITCR			0x0454
> +
> +/* System Controller Registers */
> +#define SYSCTRL			0x0464
> +
> +/* System registers */
> +#define LPX_PERIOD		3
> +
> +/* Lane enable PPI and DSI register bits */
> +#define LANEENABLE_CLEN		BIT(0)
> +#define LANEENABLE_L0EN		BIT(1)
> +#define LANEENABLE_L1EN		BIT(2)
> +
> +struct tc358762 {
> +	struct device *dev;
> +	struct drm_bridge bridge;
> +	struct drm_connector connector;
> +	struct regulator *regulator;
> +	struct drm_bridge *panel_bridge;
> +	bool pre_enabled;
> +	int error;
> +};
> +
> +static int tc358762_clear_error(struct tc358762 *ctx)
> +{
> +	int ret = ctx->error;
> +
> +	ctx->error = 0;
> +	return ret;
> +}
> +
> +static void tc358762_write(struct tc358762 *ctx, u16 addr, u32 val)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	ssize_t ret;
> +	u8 data[6];
> +
> +	if (ctx->error)
> +		return;
> +
> +	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));
> +	if (ret < 0)
> +		ctx->error = ret;
> +}
> +
> +static inline struct tc358762 *bridge_to_tc358762(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct tc358762, bridge);
> +}
> +
> +static int tc358762_init(struct tc358762 *ctx)
> +{
> +	tc358762_write(ctx, DSI_LANEENABLE,
> +		       LANEENABLE_L0EN | LANEENABLE_CLEN);
> +	tc358762_write(ctx, PPI_D0S_CLRSIPOCOUNT, 5);
> +	tc358762_write(ctx, PPI_D1S_CLRSIPOCOUNT, 5);
> +	tc358762_write(ctx, PPI_D0S_ATMR, 0);
> +	tc358762_write(ctx, PPI_D1S_ATMR, 0);
> +	tc358762_write(ctx, PPI_LPTXTIMECNT, LPX_PERIOD);
> +
> +	tc358762_write(ctx, SPICMR, 0x00);
> +	tc358762_write(ctx, LCDCTRL, 0x00100150);
> +	tc358762_write(ctx, SYSCTRL, 0x040f);
> +	msleep(100);
> +
> +	tc358762_write(ctx, PPI_STARTPPI, PPI_START_FUNCTION);
> +	tc358762_write(ctx, DSI_STARTDSI, DSI_RX_START);
> +
> +	msleep(100);
> +
> +	return tc358762_clear_error(ctx);
> +}
> +
> +static void tc358762_post_disable(struct drm_bridge *bridge)
> +{
> +	struct tc358762 *ctx = bridge_to_tc358762(bridge);
> +	int ret;
> +
> +	/*
> +	 * The post_disable hook might be called multiple times.
> +	 * We want to avoid regulator imbalance below.
> +	 */
> +	if (!ctx->pre_enabled)
> +		return;
> +
> +	ctx->pre_enabled = false;
> +
> +	ret = regulator_disable(ctx->regulator);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "error disabling regulators (%d)\n", ret);
> +}
> +
> +static void tc358762_pre_enable(struct drm_bridge *bridge)
> +{
> +	struct tc358762 *ctx = bridge_to_tc358762(bridge);
> +	int ret;
> +
> +	ret = regulator_enable(ctx->regulator);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "error enabling regulators (%d)\n", ret);
> +
> +	ret = tc358762_init(ctx);
> +	if (ret < 0)
> +		dev_err(ctx->dev, "error initializing bridge (%d)\n", ret);
> +
> +	ctx->pre_enabled = true;
> +}
> +
> +static int tc358762_attach(struct drm_bridge *bridge,
> +			   enum drm_bridge_attach_flags flags)
> +{
> +	struct tc358762 *ctx = bridge_to_tc358762(bridge);
> +
> +	return drm_bridge_attach(bridge->encoder, ctx->panel_bridge,
> +				 bridge, flags);
> +}
> +
> +static const struct drm_bridge_funcs tc358762_bridge_funcs = {
> +	.post_disable = tc358762_post_disable,
> +	.pre_enable = tc358762_pre_enable,
> +	.attach = tc358762_attach,
> +};
> +
> +static int tc358762_parse_dt(struct tc358762 *ctx)
> +{
> +	struct drm_bridge *panel_bridge;
> +	struct device *dev = ctx->dev;
> +	struct drm_panel *panel;
> +	int ret;
> +
> +	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, 0, &panel, NULL);
> +	if (ret)
> +		return ret;
> +
> +	panel_bridge = devm_drm_panel_bridge_add(dev, panel);
> +
> +	if (IS_ERR(panel_bridge))
> +		return PTR_ERR(panel_bridge);
> +
> +	ctx->panel_bridge = panel_bridge;
> +
> +	return 0;
> +}
> +
> +static int tc358762_configure_regulators(struct tc358762 *ctx)
> +{
> +	ctx->regulator = devm_regulator_get(ctx->dev, "vddc");
> +	if (IS_ERR(ctx->regulator))
> +		return PTR_ERR(ctx->regulator);
> +
> +	return 0;
> +}
> +
> +static int tc358762_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	struct tc358762 *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(struct tc358762), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	ctx->dev = dev;
> +	ctx->pre_enabled = false;
> +
> +	/* TODO: Find out how to get dual-lane mode working */
> +	dsi->lanes = 1;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> +			  MIPI_DSI_MODE_LPM;
> +
> +	ret = tc358762_parse_dt(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = tc358762_configure_regulators(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->bridge.funcs = &tc358762_bridge_funcs;
> +	ctx->bridge.type = DRM_MODE_CONNECTOR_DPI;
> +	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 tc358762_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct tc358762 *ctx = mipi_dsi_get_drvdata(dsi);
> +
> +	mipi_dsi_detach(dsi);
> +	drm_bridge_remove(&ctx->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id tc358762_of_match[] = {
> +	{ .compatible = "toshiba,tc358762" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, tc358762_of_match);
> +
> +static struct mipi_dsi_driver tc358762_driver = {
> +	.probe = tc358762_probe,
> +	.remove = tc358762_remove,
> +	.driver = {
> +		.name = "tc358762",
> +		.of_match_table = tc358762_of_match,
> +	},
> +};
> +module_mipi_dsi_driver(tc358762_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
> +MODULE_DESCRIPTION("MIPI-DSI based Driver for TC358762 DSI/DPI Bridge");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.28.0