The i.MX8MP contains two syscon registers which are responsible for configuring the on-SoC DPI-to-LVDS serializer. Implement a simple bridge driver for this serializer.

Reviewed-by: Sam Ravnborg sam@ravnborg.org Signed-off-by: Marek Vasut marex@denx.de Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Cc: Lucas Stach l.stach@pengutronix.de Cc: Maxime Ripard maxime@cerno.tech Cc: Peng Fan peng.fan@nxp.com Cc: Robby Cai robby.cai@nxp.com Cc: Robert Foss robert.foss@linaro.org Cc: Sam Ravnborg sam@ravnborg.org Cc: Thomas Zimmermann tzimmermann@suse.de To: dri-devel@lists.freedesktop.org -- V2: - Rename syscon to fsl,syscon V3: - Consistently use MX8MP - Add sentinel of_device_table - Add RB from Sam V4: - Fix MODULE_DESCRIPTION to also use MX8MP - Rename to fsl-ldb altogether --- drivers/gpu/drm/bridge/Kconfig | 8 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/fsl-ldb.c | 342 +++++++++++++++++++++++++++++++ 3 files changed, 351 insertions(+) create mode 100644 drivers/gpu/drm/bridge/fsl-ldb.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index edba12dde250..acccd97335b3 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -75,6 +75,14 @@ config DRM_DISPLAY_CONNECTOR on ARM-based platforms. Saying Y here when this driver is not needed will not cause any issue.

+config DRM_FSL_LDB + tristate "Freescale i.MX8MP LDB bridge" + depends on OF + select DRM_KMS_HELPER + select DRM_PANEL_BRIDGE + help + Support for i.MX8MP DPI-to-LVDS on-SoC encoder. + config DRM_ITE_IT6505 tristate "ITE IT6505 DisplayPort bridge" depends on OF diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index bdffad2a7ed3..313f4a09bbe0 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o obj-$(CONFIG_DRM_DISPLAY_CONNECTOR) += display-connector.o +obj-$(CONFIG_DRM_FSL_LDB) += fsl-ldb.o obj-$(CONFIG_DRM_ITE_IT6505) += ite-it6505.o obj-$(CONFIG_DRM_LONTIUM_LT8912B) += lontium-lt8912b.o obj-$(CONFIG_DRM_LONTIUM_LT9211) += lontium-lt9211.o diff --git a/drivers/gpu/drm/bridge/fsl-ldb.c b/drivers/gpu/drm/bridge/fsl-ldb.c new file mode 100644 index 000000000000..c24c488fb208 --- /dev/null +++ b/drivers/gpu/drm/bridge/fsl-ldb.c @@ -0,0 +1,342 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2022 Marek Vasut marex@denx.de + */ + +#include <linux/clk.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_graph.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include <drm/drm_atomic_helper.h> +#include <drm/drm_bridge.h> +#include <drm/drm_of.h> +#include <drm/drm_panel.h> + +#define LDB_CTRL 0x5c +#define LDB_CTRL_CH0_ENABLE BIT(0) +#define LDB_CTRL_CH0_DI_SELECT BIT(1) +#define LDB_CTRL_CH1_ENABLE BIT(2) +#define LDB_CTRL_CH1_DI_SELECT BIT(3) +#define LDB_CTRL_SPLIT_MODE BIT(4) +#define LDB_CTRL_CH0_DATA_WIDTH BIT(5) +#define LDB_CTRL_CH0_BIT_MAPPING BIT(6) +#define LDB_CTRL_CH1_DATA_WIDTH BIT(7) +#define LDB_CTRL_CH1_BIT_MAPPING BIT(8) +#define LDB_CTRL_DI0_VSYNC_POLARITY BIT(9) +#define LDB_CTRL_DI1_VSYNC_POLARITY BIT(10) +#define LDB_CTRL_REG_CH0_FIFO_RESET BIT(11) +#define LDB_CTRL_REG_CH1_FIFO_RESET BIT(12) +#define LDB_CTRL_ASYNC_FIFO_ENABLE BIT(24) +#define LDB_CTRL_ASYNC_FIFO_THRESHOLD_MASK GENMASK(27, 25) + +#define LVDS_CTRL 0x128 +#define LVDS_CTRL_CH0_EN BIT(0) +#define LVDS_CTRL_CH1_EN BIT(1) +#define LVDS_CTRL_VBG_EN BIT(2) +#define LVDS_CTRL_HS_EN BIT(3) +#define LVDS_CTRL_PRE_EMPH_EN BIT(4) +#define LVDS_CTRL_PRE_EMPH_ADJ(n) (((n) & 0x7) << 5) +#define LVDS_CTRL_PRE_EMPH_ADJ_MASK GENMASK(7, 5) +#define LVDS_CTRL_CM_ADJ(n) (((n) & 0x7) << 8) +#define LVDS_CTRL_CM_ADJ_MASK GENMASK(10, 8) +#define LVDS_CTRL_CC_ADJ(n) (((n) & 0x7) << 11) +#define LVDS_CTRL_CC_ADJ_MASK GENMASK(13, 11) +#define LVDS_CTRL_SLEW_ADJ(n) (((n) & 0x7) << 14) +#define LVDS_CTRL_SLEW_ADJ_MASK GENMASK(16, 14) +#define LVDS_CTRL_VBG_ADJ(n) (((n) & 0x7) << 17) +#define LVDS_CTRL_VBG_ADJ_MASK GENMASK(19, 17) + +struct fsl_ldb { + struct device *dev; + struct drm_bridge bridge; + struct drm_bridge *panel_bridge; + struct clk *clk; + struct regmap *regmap; + bool lvds_dual_link; +}; + +static inline struct fsl_ldb *to_fsl_ldb(struct drm_bridge *bridge) +{ + return container_of(bridge, struct fsl_ldb, bridge); +} + +static int fsl_ldb_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge); + + return drm_bridge_attach(bridge->encoder, fsl_ldb->panel_bridge, + bridge, flags); +} + +static int fsl_ldb_atomic_check(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state) +{ + /* Invert DE signal polarity. */ + bridge_state->input_bus_cfg.flags &= ~(DRM_BUS_FLAG_DE_LOW | + DRM_BUS_FLAG_DE_HIGH); + if (bridge_state->output_bus_cfg.flags & DRM_BUS_FLAG_DE_LOW) + bridge_state->input_bus_cfg.flags |= DRM_BUS_FLAG_DE_HIGH; + else if (bridge_state->output_bus_cfg.flags & DRM_BUS_FLAG_DE_HIGH) + bridge_state->input_bus_cfg.flags |= DRM_BUS_FLAG_DE_LOW; + + return 0; +} + +static void fsl_ldb_atomic_enable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge); + struct drm_atomic_state *state = old_bridge_state->base.state; + const struct drm_bridge_state *bridge_state; + const struct drm_crtc_state *crtc_state; + const struct drm_display_mode *mode; + struct drm_connector *connector; + struct drm_crtc *crtc; + bool lvds_format_24bpp; + bool lvds_format_jeida; + u32 reg; + + /* Get the LVDS format from the bridge state. */ + bridge_state = drm_atomic_get_new_bridge_state(state, bridge); + + switch (bridge_state->output_bus_cfg.format) { + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG: + lvds_format_24bpp = false; + lvds_format_jeida = true; + break; + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA: + lvds_format_24bpp = true; + lvds_format_jeida = true; + break; + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG: + lvds_format_24bpp = true; + lvds_format_jeida = false; + break; + default: + /* + * Some bridges still don't set the correct LVDS bus pixel + * format, use SPWG24 default format until those are fixed. + */ + lvds_format_24bpp = true; + lvds_format_jeida = false; + dev_warn(fsl_ldb->dev, + "Unsupported LVDS bus format 0x%04x, please check output bridge driver. Falling back to SPWG24.\n", + bridge_state->output_bus_cfg.format); + break; + } + + /* + * Retrieve the CRTC adjusted mode. This requires a little dance to go + * from the bridge to the encoder, to the connector and to the CRTC. + */ + connector = drm_atomic_get_new_connector_for_encoder(state, + bridge->encoder); + crtc = drm_atomic_get_new_connector_state(state, connector)->crtc; + crtc_state = drm_atomic_get_new_crtc_state(state, crtc); + mode = &crtc_state->adjusted_mode; + + if (fsl_ldb->lvds_dual_link) + clk_set_rate(fsl_ldb->clk, mode->clock * 3500); + else + clk_set_rate(fsl_ldb->clk, mode->clock * 7000); + clk_prepare_enable(fsl_ldb->clk); + + /* Program LDB_CTRL */ + reg = LDB_CTRL_CH0_ENABLE; + + if (fsl_ldb->lvds_dual_link) + reg |= LDB_CTRL_CH1_ENABLE; + + if (lvds_format_24bpp) { + reg |= LDB_CTRL_CH0_DATA_WIDTH; + if (fsl_ldb->lvds_dual_link) + reg |= LDB_CTRL_CH1_DATA_WIDTH; + } + + if (lvds_format_jeida) { + reg |= LDB_CTRL_CH0_BIT_MAPPING; + if (fsl_ldb->lvds_dual_link) + reg |= LDB_CTRL_CH1_BIT_MAPPING; + } + + if (mode->flags & DRM_MODE_FLAG_PVSYNC) { + reg |= LDB_CTRL_DI0_VSYNC_POLARITY; + if (fsl_ldb->lvds_dual_link) + reg |= LDB_CTRL_DI1_VSYNC_POLARITY; + } + + regmap_write(fsl_ldb->regmap, LDB_CTRL, reg); + + /* Program LVDS_CTRL */ + reg = LVDS_CTRL_CC_ADJ(2) | LVDS_CTRL_PRE_EMPH_EN | + LVDS_CTRL_PRE_EMPH_ADJ(3) | LVDS_CTRL_VBG_EN; + regmap_write(fsl_ldb->regmap, LVDS_CTRL, reg); + + /* Wait for VBG to stabilize. */ + usleep_range(15, 20); + + reg |= LVDS_CTRL_CH0_EN; + if (fsl_ldb->lvds_dual_link) + reg |= LVDS_CTRL_CH1_EN; + + regmap_write(fsl_ldb->regmap, LVDS_CTRL, reg); +} + +static void fsl_ldb_atomic_disable(struct drm_bridge *bridge, + struct drm_bridge_state *old_bridge_state) +{ + struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge); + + /* Stop both channels. */ + regmap_write(fsl_ldb->regmap, LVDS_CTRL, 0); + regmap_write(fsl_ldb->regmap, LDB_CTRL, 0); + + clk_disable_unprepare(fsl_ldb->clk); +} + +#define MAX_INPUT_SEL_FORMATS 1 +static u32 * +fsl_ldb_atomic_get_input_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + u32 output_fmt, + unsigned int *num_input_fmts) +{ + u32 *input_fmts; + + *num_input_fmts = 0; + + input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts), + GFP_KERNEL); + if (!input_fmts) + return NULL; + + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24; + *num_input_fmts = MAX_INPUT_SEL_FORMATS; + + return input_fmts; +} + +static enum drm_mode_status +fsl_ldb_mode_valid(struct drm_bridge *bridge, + const struct drm_display_info *info, + const struct drm_display_mode *mode) +{ + struct fsl_ldb *fsl_ldb = to_fsl_ldb(bridge); + + if (mode->clock > (fsl_ldb->lvds_dual_link ? 80000 : 160000)) + return MODE_CLOCK_HIGH; + + return MODE_OK; +} + +static const struct drm_bridge_funcs funcs = { + .attach = fsl_ldb_attach, + .atomic_check = fsl_ldb_atomic_check, + .atomic_enable = fsl_ldb_atomic_enable, + .atomic_disable = fsl_ldb_atomic_disable, + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, + .atomic_get_input_bus_fmts = fsl_ldb_atomic_get_input_bus_fmts, + .atomic_reset = drm_atomic_helper_bridge_reset, + .mode_valid = fsl_ldb_mode_valid, +}; + +static int fsl_ldb_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *panel_node; + struct device_node *port1, *port2; + struct drm_panel *panel; + struct fsl_ldb *fsl_ldb; + int dual_link; + + fsl_ldb = devm_kzalloc(dev, sizeof(*fsl_ldb), GFP_KERNEL); + if (!fsl_ldb) + return -ENOMEM; + + fsl_ldb->dev = &pdev->dev; + fsl_ldb->bridge.funcs = &funcs; + fsl_ldb->bridge.of_node = dev->of_node; + + fsl_ldb->clk = devm_clk_get(dev, "ldb"); + if (IS_ERR(fsl_ldb->clk)) + return PTR_ERR(fsl_ldb->clk); + + fsl_ldb->regmap = syscon_node_to_regmap(dev->of_node->parent); + if (IS_ERR(fsl_ldb->regmap)) + return PTR_ERR(fsl_ldb->regmap); + + /* Locate the panel DT node. */ + panel_node = of_graph_get_remote_node(dev->of_node, 1, 0); + if (!panel_node) + return -ENXIO; + + panel = of_drm_find_panel(panel_node); + of_node_put(panel_node); + if (IS_ERR(panel)) + return PTR_ERR(panel); + + fsl_ldb->panel_bridge = devm_drm_panel_bridge_add(dev, panel); + if (IS_ERR(fsl_ldb->panel_bridge)) + return PTR_ERR(fsl_ldb->panel_bridge); + + /* Determine whether this is dual-link configuration */ + port1 = of_graph_get_port_by_id(dev->of_node, 1); + port2 = of_graph_get_port_by_id(dev->of_node, 2); + dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2); + of_node_put(port1); + of_node_put(port2); + + if (dual_link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) { + dev_err(dev, "LVDS channel pixel swap not supported.\n"); + return -EINVAL; + } + + if (dual_link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) + fsl_ldb->lvds_dual_link = true; + + platform_set_drvdata(pdev, fsl_ldb); + + drm_bridge_add(&fsl_ldb->bridge); + + return 0; +} + +static int fsl_ldb_remove(struct platform_device *pdev) +{ + struct fsl_ldb *fsl_ldb = platform_get_drvdata(pdev); + + drm_bridge_remove(&fsl_ldb->bridge); + + return 0; +} + +static const struct of_device_id fsl_ldb_match[] = { + { .compatible = "fsl,imx8mp-ldb", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, fsl_ldb_match); + +static struct platform_driver fsl_ldb_driver = { + .probe = fsl_ldb_probe, + .remove = fsl_ldb_remove, + .driver = { + .name = "fsl-ldb", + .of_match_table = fsl_ldb_match, + }, +}; +module_platform_driver(fsl_ldb_driver); + +MODULE_AUTHOR("Marek Vasut marex@denx.de"); +MODULE_DESCRIPTION("Freescale i.MX8MP LDB"); +MODULE_LICENSE("GPL");