drm/bridge: imx: Add LDB driver helper support

This patch adds a helper to support LDB drm bridge drivers for
i.MX SoCs.  Helper functions supported by this helper should
implement common logics for all LDB modules embedded in i.MX SoCs.

Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> # Colibri iMX8X, LT170410-2WHC, LP156WF1
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220611141421.718743-10-victor.liu@nxp.com

diff --git a/drivers/gpu/drm/bridge/imx/imx-ldb-helper.c b/drivers/gpu/drm/bridge/imx/imx-ldb-helper.c
new file mode 100644 (file)
index 0000000..e85eb9a
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx-ldb-helper.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ * Copyright 2019,2020,2022 NXP
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
+#include <drm/drm_print.h>
+
+#include "imx-ldb-helper.h"
+
+bool ldb_channel_is_single_link(struct ldb_channel *ldb_ch)
+{
+       return ldb_ch->link_type == LDB_CH_SINGLE_LINK;
+}
+
+bool ldb_channel_is_split_link(struct ldb_channel *ldb_ch)
+{
+       return ldb_ch->link_type == LDB_CH_DUAL_LINK_EVEN_ODD_PIXELS ||
+              ldb_ch->link_type == LDB_CH_DUAL_LINK_ODD_EVEN_PIXELS;
+}
+
+int ldb_bridge_atomic_check_helper(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;
+
+       ldb_ch->in_bus_format = bridge_state->input_bus_cfg.format;
+       ldb_ch->out_bus_format = bridge_state->output_bus_cfg.format;
+
+       return 0;
+}
+
+void ldb_bridge_mode_set_helper(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 *ldb = ldb_ch->ldb;
+       bool is_split = ldb_channel_is_split_link(ldb_ch);
+
+       if (is_split)
+               ldb->ldb_ctrl |= LDB_SPLIT_MODE_EN;
+
+       switch (ldb_ch->out_bus_format) {
+       case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
+               break;
+       case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+               if (ldb_ch->chno == 0 || is_split)
+                       ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24;
+               if (ldb_ch->chno == 1 || is_split)
+                       ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24;
+               break;
+       case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+               if (ldb_ch->chno == 0 || is_split)
+                       ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24 |
+                                        LDB_BIT_MAP_CH0_JEIDA;
+               if (ldb_ch->chno == 1 || is_split)
+                       ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24 |
+                                        LDB_BIT_MAP_CH1_JEIDA;
+               break;
+       }
+}
+
+void ldb_bridge_enable_helper(struct drm_bridge *bridge)
+{
+       struct ldb_channel *ldb_ch = bridge->driver_private;
+       struct ldb *ldb = ldb_ch->ldb;
+
+       /*
+        * Platform specific bridge drivers should set ldb_ctrl properly
+        * for the enablement, so just write the ctrl_reg here.
+        */
+       regmap_write(ldb->regmap, ldb->ctrl_reg, ldb->ldb_ctrl);
+}
+
+void ldb_bridge_disable_helper(struct drm_bridge *bridge)
+{
+       struct ldb_channel *ldb_ch = bridge->driver_private;
+       struct ldb *ldb = ldb_ch->ldb;
+       bool is_split = ldb_channel_is_split_link(ldb_ch);
+
+       if (ldb_ch->chno == 0 || is_split)
+               ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
+       if (ldb_ch->chno == 1 || is_split)
+               ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
+
+       regmap_write(ldb->regmap, ldb->ctrl_reg, ldb->ldb_ctrl);
+}
+
+int ldb_bridge_attach_helper(struct drm_bridge *bridge,
+                            enum drm_bridge_attach_flags flags)
+{
+       struct ldb_channel *ldb_ch = bridge->driver_private;
+       struct ldb *ldb = ldb_ch->ldb;
+
+       if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+               DRM_DEV_ERROR(ldb->dev,
+                             "do not support creating a drm_connector\n");
+               return -EINVAL;
+       }
+
+       if (!bridge->encoder) {
+               DRM_DEV_ERROR(ldb->dev, "missing encoder\n");
+               return -ENODEV;
+       }
+
+       return drm_bridge_attach(bridge->encoder,
+                               ldb_ch->next_bridge, bridge,
+                               DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+}
+
+int ldb_init_helper(struct ldb *ldb)
+{
+       struct device *dev = ldb->dev;
+       struct device_node *np = dev->of_node;
+       struct device_node *child;
+       int ret;
+       u32 i;
+
+       ldb->regmap = syscon_node_to_regmap(np->parent);
+       if (IS_ERR(ldb->regmap)) {
+               ret = PTR_ERR(ldb->regmap);
+               if (ret != -EPROBE_DEFER)
+                       DRM_DEV_ERROR(dev, "failed to get regmap: %d\n", ret);
+               return ret;
+       }
+
+       for_each_available_child_of_node(np, child) {
+               struct ldb_channel *ldb_ch;
+
+               ret = of_property_read_u32(child, "reg", &i);
+               if (ret || i > MAX_LDB_CHAN_NUM - 1) {
+                       ret = -EINVAL;
+                       DRM_DEV_ERROR(dev,
+                                     "invalid channel node address: %u\n", i);
+                       of_node_put(child);
+                       return ret;
+               }
+
+               ldb_ch = ldb->channel[i];
+               ldb_ch->ldb = ldb;
+               ldb_ch->chno = i;
+               ldb_ch->is_available = true;
+               ldb_ch->np = child;
+
+               ldb->available_ch_cnt++;
+       }
+
+       return 0;
+}
+
+int ldb_find_next_bridge_helper(struct ldb *ldb)
+{
+       struct device *dev = ldb->dev;
+       struct ldb_channel *ldb_ch;
+       int ret, i;
+
+       for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
+               ldb_ch = ldb->channel[i];
+
+               if (!ldb_ch->is_available)
+                       continue;
+
+               ldb_ch->next_bridge = devm_drm_of_get_bridge(dev, ldb_ch->np,
+                                                            1, 0);
+               if (IS_ERR(ldb_ch->next_bridge)) {
+                       ret = PTR_ERR(ldb_ch->next_bridge);
+                       if (ret != -EPROBE_DEFER)
+                               DRM_DEV_ERROR(dev,
+                                             "failed to get next bridge: %d\n",
+                                             ret);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+void ldb_add_bridge_helper(struct ldb *ldb,
+                          const struct drm_bridge_funcs *bridge_funcs)
+{
+       struct ldb_channel *ldb_ch;
+       int i;
+
+       for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
+               ldb_ch = ldb->channel[i];
+
+               if (!ldb_ch->is_available)
+                       continue;
+
+               ldb_ch->bridge.driver_private = ldb_ch;
+               ldb_ch->bridge.funcs = bridge_funcs;
+               ldb_ch->bridge.of_node = ldb_ch->np;
+
+               drm_bridge_add(&ldb_ch->bridge);
+       }
+}
+
+void ldb_remove_bridge_helper(struct ldb *ldb)
+{
+       struct ldb_channel *ldb_ch;
+       int i;
+
+       for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
+               ldb_ch = ldb->channel[i];
+
+               if (!ldb_ch->is_available)
+                       continue;
+
+               drm_bridge_remove(&ldb_ch->bridge);
+       }
+}

diff --git a/drivers/gpu/drm/bridge/imx/imx-ldb-helper.h b/drivers/gpu/drm/bridge/imx/imx-ldb-helper.h
new file mode 100644 (file)
index 0000000..a0a5cde
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx-ldb-helper.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+/*
+ * Copyright 2019,2020,2022 NXP
+ */
+
+#ifndef __IMX_LDB_HELPER__
+#define __IMX_LDB_HELPER__
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_device.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#define LDB_CH0_MODE_EN_TO_DI0         BIT(0)
+#define LDB_CH0_MODE_EN_TO_DI1         (3 << 0)
+#define LDB_CH0_MODE_EN_MASK           (3 << 0)
+#define LDB_CH1_MODE_EN_TO_DI0         BIT(2)
+#define LDB_CH1_MODE_EN_TO_DI1         (3 << 2)
+#define LDB_CH1_MODE_EN_MASK           (3 << 2)
+#define LDB_SPLIT_MODE_EN              BIT(4)
+#define LDB_DATA_WIDTH_CH0_24          BIT(5)
+#define LDB_BIT_MAP_CH0_JEIDA          BIT(6)
+#define LDB_DATA_WIDTH_CH1_24          BIT(7)
+#define LDB_BIT_MAP_CH1_JEIDA          BIT(8)
+#define LDB_DI0_VS_POL_ACT_LOW         BIT(9)
+#define LDB_DI1_VS_POL_ACT_LOW         BIT(10)
+
+#define MAX_LDB_CHAN_NUM               2
+
+enum ldb_channel_link_type {
+       LDB_CH_SINGLE_LINK,
+       LDB_CH_DUAL_LINK_EVEN_ODD_PIXELS,
+       LDB_CH_DUAL_LINK_ODD_EVEN_PIXELS,
+};
+
+struct ldb;
+
+struct ldb_channel {
+       struct ldb *ldb;
+       struct drm_bridge bridge;
+       struct drm_bridge *next_bridge;
+       struct device_node *np;
+       u32 chno;
+       bool is_available;
+       u32 in_bus_format;
+       u32 out_bus_format;
+       enum ldb_channel_link_type link_type;
+};
+
+struct ldb {
+       struct regmap *regmap;
+       struct device *dev;
+       struct ldb_channel *channel[MAX_LDB_CHAN_NUM];
+       unsigned int ctrl_reg;
+       u32 ldb_ctrl;
+       unsigned int available_ch_cnt;
+};
+
+#define bridge_to_ldb_ch(b)    container_of(b, struct ldb_channel, bridge)
+
+bool ldb_channel_is_single_link(struct ldb_channel *ldb_ch);
+bool ldb_channel_is_split_link(struct ldb_channel *ldb_ch);
+
+int ldb_bridge_atomic_check_helper(struct drm_bridge *bridge,
+                                  struct drm_bridge_state *bridge_state,
+                                  struct drm_crtc_state *crtc_state,
+                                  struct drm_connector_state *conn_state);
+
+void ldb_bridge_mode_set_helper(struct drm_bridge *bridge,
+                               const struct drm_display_mode *mode,
+                               const struct drm_display_mode *adjusted_mode);
+
+void ldb_bridge_enable_helper(struct drm_bridge *bridge);
+
+void ldb_bridge_disable_helper(struct drm_bridge *bridge);
+
+int ldb_bridge_attach_helper(struct drm_bridge *bridge,
+                            enum drm_bridge_attach_flags flags);
+
+int ldb_init_helper(struct ldb *ldb);
+
+int ldb_find_next_bridge_helper(struct ldb *ldb);
+
+void ldb_add_bridge_helper(struct ldb *ldb,
+                          const struct drm_bridge_funcs *bridge_funcs);
+
+void ldb_remove_bridge_helper(struct ldb *ldb);
+
+#endif /* __IMX_LDB_HELPER__ */