Hey Liu, checkpatch --strict lists some nit and a warning. With those fixed feel free to add my r-b. On Wed, 17 Mar 2021 at 04:57, Liu Ying <victor.liu@xxxxxxx> wrote: > > This patch adds a drm bridge driver for i.MX8qxp LVDS display bridge(LDB) > which is officially named as pixel mapper. The LDB has two channels. > Each of them supports up to 24bpp parallel input color format and can map > the input to VESA or JEIDA standards. The two channels cannot be used > simultaneously, that is to say, the user should pick one of them to use. > Two LDB channels from two LDB instances can work together in LDB split > mode to support a dual link LVDS display. The channel indexes have to be > different. Channel0 outputs odd pixels and channel1 outputs even pixels. > This patch supports the LDB single mode and split mode. > > Signed-off-by: Liu Ying <victor.liu@xxxxxxx> > --- > Note that this patch depends on the patch 'phy: Add LVDS configuration options', > which has already been sent with the following series to add Mixel combo PHY > found in i.MX8qxp: > https://www.spinics.net/lists/arm-kernel/msg879957.html > > v5->v6: > * No change. > > v4->v5: > * Link with the imx-ldb-helper object. (Robert) > * Correspondingly, rename 'imx8qxp-ldb.c' to 'imx8qxp-ldb-drv.c'. > > v3->v4: > * No change. > > v2->v3: > * No change. > > v1->v2: > * Drop unnecessary DT validation. > * Use of_graph_get_endpoint_by_regs() and of_graph_get_remote_endpoint() to > get the input remote endpoint in imx8qxp_ldb_set_di_id(). > * Avoid using companion_port OF node after putting it in > imx8qxp_ldb_parse_dt_companion(). > * Mention i.MX8qxp LDB official name 'pixel mapper' in the bridge driver > and Kconfig help message. > > drivers/gpu/drm/bridge/imx/Kconfig | 9 + > drivers/gpu/drm/bridge/imx/Makefile | 3 + > drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c | 720 +++++++++++++++++++++++++++ > 3 files changed, 732 insertions(+) > create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c > > diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig > index 1ea1ce7..94f8db4d 100644 > --- a/drivers/gpu/drm/bridge/imx/Kconfig > +++ b/drivers/gpu/drm/bridge/imx/Kconfig > @@ -1,3 +1,12 @@ > +config DRM_IMX8QXP_LDB > + tristate "Freescale i.MX8QXP LVDS display bridge" > + depends on OF > + depends on COMMON_CLK > + select DRM_KMS_HELPER > + help > + Choose this to enable the internal LVDS Display Bridge(LDB) found in > + Freescale i.MX8qxp processor. Official name of LDB is pixel mapper. > + > config DRM_IMX8QXP_PIXEL_COMBINER > tristate "Freescale i.MX8QM/QXP pixel combiner" > depends on OF > diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile > index e74dd64..96d5d1e 100644 > --- a/drivers/gpu/drm/bridge/imx/Makefile > +++ b/drivers/gpu/drm/bridge/imx/Makefile > @@ -1,3 +1,6 @@ > +imx8qxp-ldb-objs := imx-ldb-helper.o imx8qxp-ldb-drv.o > +obj-$(CONFIG_DRM_IMX8QXP_LDB) += imx8qxp-ldb.o > + > obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o > obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o > obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK_TO_DPI) += imx8qxp-pxl2dpi.o > diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c > new file mode 100644 > index 00000000..d7f59c1 > --- /dev/null > +++ b/drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c > @@ -0,0 +1,720 @@ > +// SPDX-License-Identifier: GPL-2.0+ > + > +/* > + * Copyright 2020 NXP > + */ > + > +#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/phy/phy.h> > +#include <linux/pm_runtime.h> > +#include <linux/regmap.h> > + > +#include <drm/drm_atomic_state_helper.h> > +#include <drm/drm_bridge.h> > +#include <drm/drm_connector.h> > +#include <drm/drm_fourcc.h> > +#include <drm/drm_of.h> > +#include <drm/drm_print.h> > + > +#include "imx-ldb-helper.h" > + > +#define LDB_CH_SEL (1 << 28) > + > +#define SS_CTRL 0x20 > +#define CH_HSYNC_M(id) BIT(0 + ((id) * 2)) > +#define CH_VSYNC_M(id) BIT(1 + ((id) * 2)) > +#define CH_PHSYNC(id) BIT(0 + ((id) * 2)) > +#define CH_PVSYNC(id) BIT(1 + ((id) * 2)) > + > +#define DRIVER_NAME "imx8qxp-ldb" > + > +struct imx8qxp_ldb_channel { > + struct ldb_channel base; > + struct phy *phy; > + unsigned int di_id; > +}; > + > +struct imx8qxp_ldb { > + struct ldb base; > + struct device *dev; > + struct imx8qxp_ldb_channel channel[MAX_LDB_CHAN_NUM]; > + struct clk *clk_pixel; > + struct clk *clk_bypass; > + struct drm_bridge *companion; > + int active_chno; > +}; > + > +static inline struct imx8qxp_ldb_channel * > +base_to_imx8qxp_ldb_channel(struct ldb_channel *base) > +{ > + return container_of(base, struct imx8qxp_ldb_channel, base); > +} > + > +static inline struct imx8qxp_ldb *base_to_imx8qxp_ldb(struct ldb *base) > +{ > + return container_of(base, struct imx8qxp_ldb, base); > +} > + > +static void imx8qxp_ldb_set_phy_cfg(struct imx8qxp_ldb *imx8qxp_ldb, > + unsigned long di_clk, bool is_split, > + struct phy_configure_opts_lvds *phy_cfg) > +{ > + phy_cfg->bits_per_lane_and_dclk_cycle = 7; > + phy_cfg->lanes = 4; > + > + if (is_split) { > + phy_cfg->differential_clk_rate = di_clk / 2; > + phy_cfg->is_slave = !imx8qxp_ldb->companion; > + } else { > + phy_cfg->differential_clk_rate = di_clk; > + phy_cfg->is_slave = false; > + } > +} > + > +static int imx8qxp_ldb_bridge_atomic_check(struct drm_bridge *bridge, > + struct drm_bridge_state *bridge_state, > + struct drm_crtc_state *crtc_state, > + struct drm_connector_state *conn_state) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + struct ldb *ldb = ldb_ch->ldb; > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + base_to_imx8qxp_ldb_channel(ldb_ch); > + struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb); > + struct drm_bridge *companion = imx8qxp_ldb->companion; > + struct drm_display_mode *adj = &crtc_state->adjusted_mode; > + unsigned long di_clk = adj->clock * 1000; > + bool is_split = ldb_channel_is_split_link(ldb_ch); > + union phy_configure_opts opts = { }; > + struct phy_configure_opts_lvds *phy_cfg = &opts.lvds; > + int ret; > + > + ret = ldb_bridge_atomic_check_helper(bridge, bridge_state, > + crtc_state, conn_state); > + if (ret) > + return ret; > + > + imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg); > + ret = phy_validate(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts); > + if (ret < 0) { > + DRM_DEV_DEBUG_DRIVER(imx8qxp_ldb->dev, > + "failed to validate PHY: %d\n", ret); > + return ret; > + } > + > + if (is_split && companion) { > + ret = companion->funcs->atomic_check(companion, > + bridge_state, crtc_state, conn_state); > + if (ret) > + return ret; > + } > + > + return ret; > +} > + > +static void > +imx8qxp_ldb_bridge_mode_set(struct drm_bridge *bridge, > + const struct drm_display_mode *mode, > + const struct drm_display_mode *adjusted_mode) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + struct ldb_channel *companion_ldb_ch; > + struct ldb *ldb = ldb_ch->ldb; > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + base_to_imx8qxp_ldb_channel(ldb_ch); > + struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb); > + struct drm_bridge *companion = imx8qxp_ldb->companion; > + struct device *dev = imx8qxp_ldb->dev; > + unsigned long di_clk = adjusted_mode->clock * 1000; > + bool is_split = ldb_channel_is_split_link(ldb_ch); > + union phy_configure_opts opts = { }; > + struct phy_configure_opts_lvds *phy_cfg = &opts.lvds; > + u32 chno = ldb_ch->chno; > + int ret; > + > + ret = pm_runtime_get_sync(dev); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to get runtime PM sync: %d\n", ret); > + > + ret = phy_init(imx8qxp_ldb_ch->phy); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to initialize PHY: %d\n", ret); > + > + ret = phy_set_mode(imx8qxp_ldb_ch->phy, PHY_MODE_LVDS); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to set PHY mode: %d\n", ret); > + > + if (is_split && companion) { > + companion_ldb_ch = bridge_to_ldb_ch(companion); > + > + companion_ldb_ch->in_bus_format = ldb_ch->in_bus_format; > + companion_ldb_ch->out_bus_format = ldb_ch->out_bus_format; > + } > + > + clk_set_rate(imx8qxp_ldb->clk_bypass, di_clk); > + clk_set_rate(imx8qxp_ldb->clk_pixel, di_clk); > + > + imx8qxp_ldb_set_phy_cfg(imx8qxp_ldb, di_clk, is_split, phy_cfg); > + ret = phy_configure(imx8qxp_ldb_ch->phy, &opts); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to configure PHY: %d\n", ret); > + > + if (chno == 0) > + ldb->ldb_ctrl &= ~LDB_CH_SEL; > + else > + ldb->ldb_ctrl |= LDB_CH_SEL; > + > + /* input VSYNC signal from pixel link is active low */ > + if (imx8qxp_ldb_ch->di_id == 0) > + ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW; > + else > + ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW; > + > + /* > + * For split mode, settle input VSYNC signal polarity and > + * channel selection down early. > + */ > + if (is_split) > + regmap_write(ldb->regmap, ldb->ctrl_reg, ldb->ldb_ctrl); > + > + ldb_bridge_mode_set_helper(bridge, mode, adjusted_mode); > + > + if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC) > + regmap_update_bits(ldb->regmap, SS_CTRL, CH_VSYNC_M(chno), 0); > + else if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC) > + regmap_update_bits(ldb->regmap, SS_CTRL, > + CH_VSYNC_M(chno), CH_PVSYNC(chno)); > + > + if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC) > + regmap_update_bits(ldb->regmap, SS_CTRL, CH_HSYNC_M(chno), 0); > + else if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC) > + regmap_update_bits(ldb->regmap, SS_CTRL, > + CH_HSYNC_M(chno), CH_PHSYNC(chno)); > + > + if (is_split && companion) > + companion->funcs->mode_set(companion, mode, adjusted_mode); > +} > + > +static void > +imx8qxp_ldb_bridge_atomic_pre_enable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + struct ldb *ldb = ldb_ch->ldb; > + struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb); > + struct drm_bridge *companion = imx8qxp_ldb->companion; > + bool is_split = ldb_channel_is_split_link(ldb_ch); > + > + clk_prepare_enable(imx8qxp_ldb->clk_pixel); > + clk_prepare_enable(imx8qxp_ldb->clk_bypass); > + > + if (is_split && companion) > + companion->funcs->atomic_pre_enable(companion, old_bridge_state); > +} > + > +static void > +imx8qxp_ldb_bridge_atomic_enable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + struct ldb *ldb = ldb_ch->ldb; > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + base_to_imx8qxp_ldb_channel(ldb_ch); > + struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb); > + struct drm_bridge *companion = imx8qxp_ldb->companion; > + struct device *dev = imx8qxp_ldb->dev; > + bool is_split = ldb_channel_is_split_link(ldb_ch); > + int ret; > + > + if (ldb_ch->chno == 0 || is_split) { > + ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK; > + ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ? > + LDB_CH0_MODE_EN_TO_DI0 : LDB_CH0_MODE_EN_TO_DI1; > + } > + if (ldb_ch->chno == 1 || is_split) { > + ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK; > + ldb->ldb_ctrl |= imx8qxp_ldb_ch->di_id == 0 ? > + LDB_CH1_MODE_EN_TO_DI0 : LDB_CH1_MODE_EN_TO_DI1; > + } > + > + ldb_bridge_enable_helper(bridge); > + > + ret = phy_power_on(imx8qxp_ldb_ch->phy); > + if (ret) > + DRM_DEV_ERROR(dev, "failed to power on PHY: %d\n", ret); > + > + if (is_split && companion) > + companion->funcs->atomic_enable(companion, old_bridge_state); > +} > + > +static void > +imx8qxp_ldb_bridge_atomic_disable(struct drm_bridge *bridge, > + struct drm_bridge_state *old_bridge_state) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + struct ldb *ldb = ldb_ch->ldb; > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + base_to_imx8qxp_ldb_channel(ldb_ch); > + struct imx8qxp_ldb *imx8qxp_ldb = base_to_imx8qxp_ldb(ldb); > + struct drm_bridge *companion = imx8qxp_ldb->companion; > + struct device *dev = imx8qxp_ldb->dev; > + bool is_split = ldb_channel_is_split_link(ldb_ch); > + int ret; > + > + ret = phy_power_off(imx8qxp_ldb_ch->phy); > + if (ret) > + DRM_DEV_ERROR(dev, "failed to power off PHY: %d\n", ret); > + > + ret = phy_exit(imx8qxp_ldb_ch->phy); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to teardown PHY: %d\n", ret); > + > + ldb_bridge_disable_helper(bridge); > + > + clk_disable_unprepare(imx8qxp_ldb->clk_bypass); > + clk_disable_unprepare(imx8qxp_ldb->clk_pixel); > + > + if (is_split && companion) > + companion->funcs->atomic_disable(companion, old_bridge_state); > + > + ret = pm_runtime_put(dev); > + if (ret < 0) > + DRM_DEV_ERROR(dev, "failed to put runtime PM: %d\n", ret); > +} > + > +static const u32 imx8qxp_ldb_bus_output_fmts[] = { > + MEDIA_BUS_FMT_RGB666_1X7X3_SPWG, > + MEDIA_BUS_FMT_RGB888_1X7X4_SPWG, > + MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA, > + MEDIA_BUS_FMT_FIXED, > +}; > + > +static bool imx8qxp_ldb_bus_output_fmt_supported(u32 fmt) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts); i++) { > + if (imx8qxp_ldb_bus_output_fmts[i] == fmt) > + return true; > + } > + > + return false; > +} > + > +static u32 * > +imx8qxp_ldb_bridge_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) > +{ > + struct drm_display_info *di; > + const struct drm_format_info *finfo; > + u32 *input_fmts; > + > + if (!imx8qxp_ldb_bus_output_fmt_supported(output_fmt)) > + return NULL; > + > + *num_input_fmts = 1; > + > + input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL); > + if (!input_fmts) > + return NULL; > + > + switch (output_fmt) { > + case MEDIA_BUS_FMT_FIXED: > + di = &conn_state->connector->display_info; > + > + /* > + * Look at the first bus format to determine input format. > + * Default to MEDIA_BUS_FMT_RGB888_1X24, if no match. > + */ > + if (di->num_bus_formats) { > + finfo = drm_format_info(di->bus_formats[0]); > + > + input_fmts[0] = finfo->depth == 18 ? > + MEDIA_BUS_FMT_RGB666_1X24_CPADHI : > + MEDIA_BUS_FMT_RGB888_1X24; > + } else { > + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24; > + } > + break; > + case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG: > + input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X24_CPADHI; > + break; > + case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG: > + case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA: > + input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24; > + break; > + default: > + kfree(input_fmts); > + input_fmts = NULL; > + break; > + } > + > + return input_fmts; > +} > + > +static u32 * > +imx8qxp_ldb_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge, > + struct drm_bridge_state *bridge_state, > + struct drm_crtc_state *crtc_state, > + struct drm_connector_state *conn_state, > + unsigned int *num_output_fmts) > +{ > + *num_output_fmts = ARRAY_SIZE(imx8qxp_ldb_bus_output_fmts); > + return kmemdup(imx8qxp_ldb_bus_output_fmts, > + sizeof(imx8qxp_ldb_bus_output_fmts), GFP_KERNEL); > +} > + > +static enum drm_mode_status > +imx8qxp_ldb_bridge_mode_valid(struct drm_bridge *bridge, > + const struct drm_display_info *info, > + const struct drm_display_mode *mode) > +{ > + struct ldb_channel *ldb_ch = bridge->driver_private; > + bool is_single = ldb_channel_is_single_link(ldb_ch); > + > + if (mode->clock > 170000) > + return MODE_CLOCK_HIGH; > + > + if (mode->clock > 150000 && is_single) > + return MODE_CLOCK_HIGH; > + > + return MODE_OK; > +} > + > +static const struct drm_bridge_funcs imx8qxp_ldb_bridge_funcs = { > + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, > + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, > + .atomic_reset = drm_atomic_helper_bridge_reset, > + .mode_valid = imx8qxp_ldb_bridge_mode_valid, > + .attach = ldb_bridge_attach_helper, > + .atomic_check = imx8qxp_ldb_bridge_atomic_check, > + .mode_set = imx8qxp_ldb_bridge_mode_set, > + .atomic_pre_enable = imx8qxp_ldb_bridge_atomic_pre_enable, > + .atomic_enable = imx8qxp_ldb_bridge_atomic_enable, > + .atomic_disable = imx8qxp_ldb_bridge_atomic_disable, > + .atomic_get_input_bus_fmts = > + imx8qxp_ldb_bridge_atomic_get_input_bus_fmts, > + .atomic_get_output_bus_fmts = > + imx8qxp_ldb_bridge_atomic_get_output_bus_fmts, > +}; > + > +static int imx8qxp_ldb_set_di_id(struct imx8qxp_ldb *imx8qxp_ldb) > +{ > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno]; > + struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base; > + struct device_node *ep, *remote; > + struct device *dev = imx8qxp_ldb->dev; > + struct of_endpoint endpoint; > + int ret; > + > + ep = of_graph_get_endpoint_by_regs(ldb_ch->np, 0, -1); > + if (!ep) { > + DRM_DEV_ERROR(dev, "failed to get port0 endpoint\n"); > + return -EINVAL; > + } > + > + remote = of_graph_get_remote_endpoint(ep); > + of_node_put(ep); > + if (!remote) { > + DRM_DEV_ERROR(dev, "failed to get port0 remote endpoint\n"); > + return -EINVAL; > + } > + > + ret = of_graph_parse_endpoint(remote, &endpoint); > + of_node_put(remote); > + if (ret) { > + DRM_DEV_ERROR(dev, "failed to parse port0 remote endpoint: %d\n", > + ret); > + return ret; > + } > + > + imx8qxp_ldb_ch->di_id = endpoint.id; > + > + return 0; > +} > + > +static int > +imx8qxp_ldb_check_chno_and_dual_link(struct ldb_channel *ldb_ch, int link) > +{ > + if ((link == DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS && ldb_ch->chno != 0) || > + (link == DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS && ldb_ch->chno != 1)) > + return -EINVAL; > + > + return 0; > +} > + > +static int imx8qxp_ldb_parse_dt_companion(struct imx8qxp_ldb *imx8qxp_ldb) > +{ > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch = > + &imx8qxp_ldb->channel[imx8qxp_ldb->active_chno]; > + struct ldb_channel *ldb_ch = &imx8qxp_ldb_ch->base; > + struct ldb_channel *companion_ldb_ch; > + struct device_node *companion; > + struct device_node *child; > + struct device_node *companion_port = NULL; > + struct device_node *port1, *port2; > + struct device *dev = imx8qxp_ldb->dev; > + const struct of_device_id *match; > + u32 i; > + int dual_link; > + int ret; > + > + /* Locate the companion LDB for dual-link operation, if any. */ > + companion = of_parse_phandle(dev->of_node, "fsl,companion-ldb", 0); > + if (!companion) > + return 0; > + > + if (!of_device_is_available(companion)) { > + DRM_DEV_ERROR(dev, "companion LDB is not available\n"); > + ret = -ENODEV; > + goto out; > + } > + > + /* > + * Sanity check: the companion bridge must have the same compatible > + * string. > + */ > + match = of_match_device(dev->driver->of_match_table, dev); > + if (!of_device_is_compatible(companion, match->compatible)) { > + DRM_DEV_ERROR(dev, "companion LDB is incompatible\n"); > + ret = -ENXIO; > + goto out; > + } > + > + for_each_available_child_of_node(companion, child) { > + ret = of_property_read_u32(child, "reg", &i); > + if (ret || i > MAX_LDB_CHAN_NUM - 1) { > + DRM_DEV_ERROR(dev, > + "invalid channel node address: %u\n", i); > + ret = -EINVAL; > + of_node_put(child); > + goto out; > + } > + > + /* > + * Channel numbers have to be different, because channel0 > + * transmits odd pixels and channel1 transmits even pixels. > + */ > + if (i == (ldb_ch->chno ^ 0x1)) { > + companion_port = child; > + break; > + } > + } > + > + if (companion_port == NULL) { > + DRM_DEV_ERROR(dev, > + "failed to find companion LDB channel port\n"); > + ret = -EINVAL; > + goto out; > + } > + > + /* > + * We need to work out if the sink is expecting us to function in > + * dual-link mode. We do this by looking at the DT port nodes we are > + * connected to. If they are marked as expecting odd pixels and > + * even pixels than we need to enable LDB split mode. > + */ > + port1 = of_graph_get_port_by_id(ldb_ch->np, 1); > + port2 = of_graph_get_port_by_id(companion_port, 1); > + dual_link = drm_of_lvds_get_dual_link_pixel_order(port1, port2); > + of_node_put(port1); > + of_node_put(port2); > + > + switch (dual_link) { > + case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS: > + ldb_ch->link_type = LDB_CH_DUAL_LINK_ODD_EVEN_PIXELS; > + break; > + case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS: > + ldb_ch->link_type = LDB_CH_DUAL_LINK_EVEN_ODD_PIXELS; > + break; > + default: > + ret = dual_link; > + DRM_DEV_ERROR(dev, > + "failed to get dual link pixel order: %d\n", ret); > + goto out; > + } > + > + ret = imx8qxp_ldb_check_chno_and_dual_link(ldb_ch, dual_link); > + if (ret < 0) { > + DRM_DEV_ERROR(dev, > + "unmatched channel number(%u) vs dual link(%d)\n", > + ldb_ch->chno, dual_link); > + goto out; > + } > + > + imx8qxp_ldb->companion = of_drm_find_bridge(companion_port); > + if (!imx8qxp_ldb->companion) { > + ret = -EPROBE_DEFER; > + DRM_DEV_DEBUG_DRIVER(dev, > + "failed to find bridge for companion bridge: %d\n", ret); > + goto out; > + } > + > + DRM_DEV_DEBUG_DRIVER(dev, > + "dual-link configuration detected (companion bridge %pOF)\n", > + companion); > + > + companion_ldb_ch = bridge_to_ldb_ch(imx8qxp_ldb->companion); > + companion_ldb_ch->link_type = ldb_ch->link_type; > +out: > + of_node_put(companion_port); > + of_node_put(companion); > + return ret; > +} > + > +static int imx8qxp_ldb_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct imx8qxp_ldb *imx8qxp_ldb; > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch; > + struct ldb *ldb; > + struct ldb_channel *ldb_ch; > + int ret, i; > + > + imx8qxp_ldb = devm_kzalloc(dev, sizeof(*imx8qxp_ldb), GFP_KERNEL); > + if (!imx8qxp_ldb) > + return -ENOMEM; > + > + imx8qxp_ldb->clk_pixel = devm_clk_get(dev, "pixel"); > + if (IS_ERR(imx8qxp_ldb->clk_pixel)) { > + ret = PTR_ERR(imx8qxp_ldb->clk_pixel); > + if (ret != -EPROBE_DEFER) > + DRM_DEV_ERROR(dev, > + "failed to get pixel clock: %d\n", ret); > + return ret; > + } > + > + imx8qxp_ldb->clk_bypass = devm_clk_get(dev, "bypass"); > + if (IS_ERR(imx8qxp_ldb->clk_bypass)) { > + ret = PTR_ERR(imx8qxp_ldb->clk_bypass); > + if (ret != -EPROBE_DEFER) > + DRM_DEV_ERROR(dev, > + "failed to get bypass clock: %d\n", ret); > + return ret; > + } > + > + imx8qxp_ldb->dev = dev; > + > + ldb = &imx8qxp_ldb->base; > + ldb->dev = dev; > + ldb->ctrl_reg = 0xe0; > + > + for (i = 0; i < MAX_LDB_CHAN_NUM; i++) > + ldb->channel[i] = &imx8qxp_ldb->channel[i].base; > + > + ret = ldb_init_helper(ldb); > + if (ret) > + return ret; > + > + if (ldb->available_ch_cnt == 0) { > + DRM_DEV_DEBUG_DRIVER(dev, "no available channel\n"); > + return 0; > + } else if (ldb->available_ch_cnt > 1) { > + DRM_DEV_ERROR(dev, "invalid available channel number(%u)\n", > + ldb->available_ch_cnt); > + return -ENOTSUPP; > + } WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP #683: FILE: drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c:625: + return -ENOTSUPP; Maybe -EINVAL is a better return value.