[PATCH v8 09/14] drm/bridge: imx: Add LDB driver helper support

Liu Ying
2022-06-09T06:49:27Z

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>
---
Marcel, I add your T-b tag from v6, let me know if you want me to drop it, as
the checkpatch fix in v7 and the rebase in v8 are trivial.

v7->v8:
* Use devm_drm_of_get_bridge() due to the rebase upon v5.19-rc1.

v6->v7:
* Fix below complaints from 'checkpatch.pl --strict'. (Robert)
- 'Alignment should match open parenthesis'
- 'Prefer using the BIT macro'
* Add Marcel's T-b tag.
* Add Robert's R-b tag.

v5->v6:
* No change.

v4->v5:
* Make imx-ldb-helper be a pure object to be linked with i.MX8qxp LDB bridge
driver and i.MX8qm LDB bridge driver. (Robert)
* Move 'imx_ldb_helper.h' to 'drivers/gpu/drm/bridge/imx/imx-ldb-helper.h'.
(Robert)
* s/__FSL_IMX_LDB__/__IMX_LDB_HELPER__/ for 'imx-ldb-helper.h'.

v3->v4:
* No change.

v2->v3:
* Call syscon_node_to_regmap() to get regmap instead of
syscon_regmap_lookup_by_phandle().

v1->v2:
* No change.

drivers/gpu/drm/bridge/imx/imx-ldb-helper.c | 220 ++++++++++++++++++++
drivers/gpu/drm/bridge/imx/imx-ldb-helper.h | 96 +++++++++
2 files changed, 316 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/imx/imx-ldb-helper.c
create mode 100644 drivers/gpu/drm/bridge/imx/imx-ldb-helper.h

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
index 000000000000..e85eb9ab5947
--- /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
index 000000000000..a0a5cde27fbc
--- /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__ */
--
2.25.1