[PATCH v8 1/4] drm/bridge: add support for sn65dsi86 bridge driver

Sandeep Panda
2018-06-05T05:40:15Z

Add support for TI's sn65dsi86 dsi2edp bridge chip.
The chip converts DSI transmitted signal to eDP signal,
which is fed to the connected eDP panel.

This chip can be controlled via either i2c interface or
dsi interface. Currently in driver all the control registers
are being accessed through i2c interface only.
Also as of now HPD support has not been added to bridge
chip driver.

Changes in v1:
- Split the dt-bindings and the driver support into separate patches
(Andrzej Hajda).
- Use of gpiod APIs to parse and configure gpios instead of obsolete ones
(Andrzej Hajda).
- Use macros to define the register offsets (Andrzej Hajda).

Changes in v2:
- Separate out edp panel specific HW resource handling from bridge
driver and create a separate edp panel drivers to handle panel
specific mode information and HW resources (Sean Paul).
- Replace pr_* APIs to DRM_* APIs to log error or debug information
(Sean Paul).
- Remove some of the unnecessary structure/variable from driver (Sean
Paul).
- Rename the function and structure prefix "sn65dsi86" to "ti_sn_bridge"
(Sean Paul / Rob Herring).
- Remove most of the hard-coding and modified the bridge init sequence
based on current mode (Sean Paul).
- Remove the existing function to retrieve the EDID data and
implemented this as an i2c_adapter and use drm_get_edid() (Sean Paul).
- Remove the dummy irq handler implementation, will add back the
proper irq handling later (Sean Paul).
- Capture the required enable gpios in a single array based on dt entry
instead of having individual descriptor for each gpio (Sean Paul).

Changes in v3:
- Remove usage of irq_gpio and replace it as "interrupts" property (Rob
Herring).
- Remove the unnecessary header file inclusions (Sean Paul).
- Rearrange the header files in alphabetical order (Sean Paul).
- Use regmap interface to perform i2c transactions.
- Update Copyright/License field and address other review comments
(Jordan Crouse).

Changes in v4:
- Update License/Copyright (Sean Paul).
- Add Kconfig and Makefile changes (Sean Paul).
- Drop i2c gpio handling from this bridge driver, since i2c sda/scl gpios
will be handled by i2c master.
- Update required supplies names.
- Remove unnecessary goto statements (Sean Paul).
- Add mutex lock to power_ctrl API to avoid race conditions (Sean
Paul).
- Add support to parse reference clk frequency from dt(optional).
- Update the bridge chip enable/disable sequence.

Changes in v5:
- Fixed Kbuild test service reported warnings.

Changes in v6:
- Use PM runtime based ref-counting instead of local ref_count mechanism
(Stephen Boyd).
- Clean up some debug logs and indentations (Sean Paul).
- Simplify dp rate calculation (Sean Paul).
- Add support to configure refclk based on input REFCLK pin or DACP/N
pin (Stephen Boyd).

Changes in v7:
- Use static supply entries instead of dynamic allocation (Andrzej
Hajda).
- Defer bridge driver probe if panel is not probed (Andrzej Hajda).
- Update of_graph APIs for correct node reference management. (Andrzej
Hajda).
- Remove local display_mode object (Andrzej Hajda).
- Remove version id check function from driver.

Changes in v8:
- Move dsi register/attach function to bridge driver probe (Andrzej
Hajda).
- Introduce a new helper function to write 16bit words into consecutive
registers (Andrzej Hajda).
- Remove unnecessary macros (Andrzej Hajda).

Signed-off-by: Sandeep Panda <spanda@codeaurora.org>
---
drivers/gpu/drm/bridge/Kconfig | 9 +
drivers/gpu/drm/bridge/Makefile | 1 +
drivers/gpu/drm/bridge/ti-sn65dsi86.c | 666 ++++++++++++++++++++++++++++++++++
3 files changed, 676 insertions(+)
create mode 100644 drivers/gpu/drm/bridge/ti-sn65dsi86.c

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 3b99d5a..8153150 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -108,6 +108,15 @@ config DRM_TI_TFP410
---help---
Texas Instruments TFP410 DVI/HDMI Transmitter driver

+config DRM_TI_SN65DSI86
+ tristate "TI SN65DSI86 DSI to eDP bridge"
+ depends on OF
+ select DRM_KMS_HELPER
+ select REGMAP_I2C
+ select DRM_PANEL
+ ---help---
+ Texas Instruments SN65DSI86 DSI to eDP Bridge driver
+
source "drivers/gpu/drm/bridge/analogix/Kconfig"

source "drivers/gpu/drm/bridge/adv7511/Kconfig"
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 373eb28..3711be8 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -12,4 +12,5 @@ obj-$(CONFIG_DRM_TOSHIBA_TC358767) += tc358767.o
obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix/
obj-$(CONFIG_DRM_I2C_ADV7511) += adv7511/
obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
+obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
obj-y += synopsys/
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
new file mode 100644
index 0000000..add6e0f
--- /dev/null
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
@@ -0,0 +1,666 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/of_graph.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+/* Link Training specific registers */
+#define SN_DEVICE_REV_REG 0x08
+#define SN_HPD_DISABLE_REG 0x5C
+#define SN_REFCLK_FREQ_REG 0x0A
+#define SN_DSI_LANES_REG 0x10
+#define SN_DSIA_CLK_FREQ_REG 0x12
+#define SN_ENH_FRAME_REG 0x5A
+#define SN_SSC_CONFIG_REG 0x93
+#define SN_DATARATE_CONFIG_REG 0x94
+#define SN_PLL_ENABLE_REG 0x0D
+#define SN_SCRAMBLE_CONFIG_REG 0x95
+#define SN_AUX_WDATA0_REG 0x64
+#define SN_AUX_ADDR_19_16_REG 0x74
+#define SN_AUX_ADDR_15_8_REG 0x75
+#define SN_AUX_ADDR_7_0_REG 0x76
+#define SN_AUX_LENGTH_REG 0x77
+#define SN_AUX_CMD_REG 0x78
+#define SN_ML_TX_MODE_REG 0x96
+/* video config specific registers */
+#define SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG 0x20
+#define SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG 0x24
+#define SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG 0x2C
+#define SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG 0x30
+#define SN_CHA_HORIZONTAL_BACK_PORCH_REG 0x34
+#define SN_CHA_VERTICAL_BACK_PORCH_REG 0x36
+#define SN_CHA_HORIZONTAL_FRONT_PORCH_REG 0x38
+#define SN_CHA_VERTICAL_FRONT_PORCH_REG 0x3A
+#define SN_DATA_FORMAT_REG 0x5B
+
+#define MIN_DSI_CLK_FREQ_MHZ 40
+
+/* fudge factor required to account for 8b/10b encoding */
+#define DP_CLK_FUDGE_NUM 10
+#define DP_CLK_FUDGE_DEN 8
+
+#define DPPLL_CLK_SRC_REFCLK 0
+#define DPPLL_CLK_SRC_DSICLK 1
+
+#define SN_DSIA_REFCLK_OFFSET 1
+#define SN_DSIA_LANE_OFFSET 3
+#define SN_DP_LANE_OFFSET 4
+#define SN_DP_DATA_RATE_OFFSET 5
+
+#define SN_ENABLE_VID_STREAM_BIT BIT(3)
+#define SN_DSIA_NUM_LANES_BITS (BIT(4) | BIT(3))
+#define SN_DP_NUM_LANES_BITS (BIT(5) | BIT(4))
+#define SN_DP_DATA_RATE_BITS (BIT(7) | BIT(6) | BIT(5))
+#define SN_HPD_DISABLE_BIT BIT(0)
+
+#define SN_REGULATOR_SUPPLY_NUM 4
+
+struct ti_sn_bridge {
+ struct device *dev;
+ struct regmap *regmap;
+ struct drm_bridge bridge;
+ struct drm_connector connector;
+ struct device_node *host_node;
+ struct mipi_dsi_device *dsi;
+ struct clk *refclk;
+ struct drm_panel *panel;
+ struct gpio_desc *enable_gpio;
+ struct regulator_bulk_data supplies[SN_REGULATOR_SUPPLY_NUM];
+ struct i2c_adapter *ddc;
+};
+
+static const struct regmap_range ti_sn_bridge_volatile_ranges[] = {
+ { .range_min = 0, .range_max = 0xFF },
+};
+
+static const struct regmap_access_table ti_sn_bridge_volatile_table = {
+ .yes_ranges = ti_sn_bridge_volatile_ranges,
+ .n_yes_ranges = ARRAY_SIZE(ti_sn_bridge_volatile_ranges),
+};
+
+static const struct regmap_config ti_sn_bridge_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .volatile_table = &ti_sn_bridge_volatile_table,
+ .cache_type = REGCACHE_NONE,
+};
+
+static void ti_sn_bridge_write_u16(struct ti_sn_bridge *pdata,
+ unsigned int reg, u16 val)
+{
+ regmap_write(pdata->regmap, reg, val & 0xFF);
+ regmap_write(pdata->regmap, reg + 1, val >> 8);
+}
+
+static int __maybe_unused ti_sn_bridge_resume(struct device *dev)
+{
+ struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
+ int ret = 0;
+
+ ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
+ if (ret) {
+ DRM_ERROR("failed to enable supplies %d\n", ret);
+ return ret;
+ }
+
+ gpiod_set_value(pdata->enable_gpio, 1);
+
+ return ret;
+}
+
+static int __maybe_unused ti_sn_bridge_suspend(struct device *dev)
+{
+ struct ti_sn_bridge *pdata = dev_get_drvdata(dev);
+ int ret = 0;
+
+ gpiod_set_value(pdata->enable_gpio, 0);
+
+ ret = regulator_bulk_disable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies);
+ if (ret)
+ DRM_ERROR("failed to disable supplies %d\n", ret);
+
+ return ret;
+}
+
+static const struct dev_pm_ops ti_sn_bridge_pm_ops = {
+ SET_RUNTIME_PM_OPS(ti_sn_bridge_suspend, ti_sn_bridge_resume, NULL)
+};
+
+/* Connector funcs */
+static struct ti_sn_bridge *
+connector_to_ti_sn_bridge(struct drm_connector *connector)
+{
+ return container_of(connector, struct ti_sn_bridge, connector);
+}
+
+static int ti_sn_bridge_connector_get_modes(struct drm_connector *connector)
+{
+ struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
+ struct edid *edid;
+ u32 num_modes;
+
+ if (pdata->panel) {
+ DRM_DEBUG_KMS("get mode from connected drm_panel\n");
+ return drm_panel_get_modes(pdata->panel);
+ }
+
+ if (!pdata->ddc)
+ return 0;
+
+ pm_runtime_get_sync(pdata->dev);
+ edid = drm_get_edid(connector, pdata->ddc);
+ pm_runtime_put_sync(pdata->dev);
+ if (!edid)
+ return 0;
+
+ drm_mode_connector_update_edid_property(connector, edid);
+ num_modes = drm_add_edid_modes(connector, edid);
+ kfree(edid);
+
+ return num_modes;
+}
+
+static enum drm_mode_status
+ti_sn_bridge_connector_mode_valid(struct drm_connector *connector,
+ struct drm_display_mode *mode)
+{
+ /* maximum supported resolution is 4K at 60 fps */
+ if (mode->clock > 594000)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+}
+
+static struct drm_connector_helper_funcs ti_sn_bridge_connector_helper_funcs = {
+ .get_modes = ti_sn_bridge_connector_get_modes,
+ .mode_valid = ti_sn_bridge_connector_mode_valid,
+};
+
+static enum drm_connector_status
+ti_sn_bridge_connector_detect(struct drm_connector *connector, bool force)
+{
+ struct ti_sn_bridge *pdata = connector_to_ti_sn_bridge(connector);
+
+ /**
+ * TODO: Currently if drm_panel is present, then always
+ * return the status as connected. Need to add support to detect
+ * device state for no panel(hot pluggable) scenarios.
+ */
+ if (pdata->panel)
+ return connector_status_connected;
+ else
+ return connector_status_unknown;
+}
+
+static const struct drm_connector_funcs ti_sn_bridge_connector_funcs = {
+ .fill_modes = drm_helper_probe_single_connector_modes,
+ .detect = ti_sn_bridge_connector_detect,
+ .destroy = drm_connector_cleanup,
+ .reset = drm_atomic_helper_connector_reset,
+ .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+ .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static struct ti_sn_bridge *bridge_to_ti_sn_bridge(struct drm_bridge *bridge)
+{
+ return container_of(bridge, struct ti_sn_bridge, bridge);
+}
+
+static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
+{
+ unsigned int i;
+ const char * const ti_sn_bridge_supply_names[] = {
+ "vcca", "vcc", "vccio", "vpll",
+ };
+
+ for (i = 0; i < SN_REGULATOR_SUPPLY_NUM; i++)
+ pdata->supplies[i].supply = ti_sn_bridge_supply_names[i];
+
+ return devm_regulator_bulk_get(pdata->dev, SN_REGULATOR_SUPPLY_NUM,
+ pdata->supplies);
+}
+
+static int ti_sn_bridge_attach(struct drm_bridge *bridge)
+{
+ struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
+ int ret;
+
+ ret = drm_connector_init(bridge->dev, &pdata->connector,
+ &ti_sn_bridge_connector_funcs,
+ DRM_MODE_CONNECTOR_eDP);
+ if (ret) {
+ DRM_ERROR("Failed to initialize connector with drm\n");
+ return ret;
+ }
+
+ drm_connector_helper_add(&pdata->connector,
+ &ti_sn_bridge_connector_helper_funcs);
+ drm_mode_connector_attach_encoder(&pdata->connector, bridge->encoder);
+
+ /* attach panel to bridge */
+ if (pdata->panel)
+ drm_panel_attach(pdata->panel, &pdata->connector);
+
+ return 0;
+}
+
+static void ti_sn_bridge_disable(struct drm_bridge *bridge)
+{
+ struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
+
+ if (pdata->panel) {
+ drm_panel_disable(pdata->panel);
+ drm_panel_unprepare(pdata->panel);
+ }
+
+ /* disable video stream */
+ regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG,
+ SN_ENABLE_VID_STREAM_BIT, 0);
+ /* semi auto link training mode OFF */
+ regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0);
+ /* disable DP PLL */
+ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 0);
+}
+
+static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
+{
+ u32 bit_rate_khz, clk_freq_khz;
+ struct drm_display_mode *mode =
+ &pdata->bridge.encoder->crtc->state->adjusted_mode;
+
+ bit_rate_khz = mode->clock *
+ mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
+ clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
+
+ return clk_freq_khz;
+}
+
+#define REFCLK_LUT_SIZE 5
+
+/* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
+static const u32 ti_sn_bridge_refclk_lut[] = {
+ 12000000,
+ 19200000,
+ 26000000,
+ 27000000,
+ 38400000,
+};
+
+/* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
+static const u32 ti_sn_bridge_dsiclk_lut[] = {
+ 468000000,
+ 384000000,
+ 416000000,
+ 486000000,
+ 460800000,
+};
+
+static void ti_sn_bridge_set_refclk(struct ti_sn_bridge *pdata)
+{
+ int i = 0;
+ u8 refclk_src;
+ u32 refclk_rate;
+ const u32 *refclk_lut;
+
+ if (pdata->refclk) {
+ refclk_src = DPPLL_CLK_SRC_REFCLK;
+ refclk_rate = clk_get_rate(pdata->refclk);
+ refclk_lut = ti_sn_bridge_refclk_lut;
+ clk_prepare_enable(pdata->refclk);
+ } else {
+ refclk_src = DPPLL_CLK_SRC_DSICLK;
+ refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
+ refclk_lut = ti_sn_bridge_dsiclk_lut;
+ }
+
+ /* for i equals to REFCLK_LUT_SIZE means default frequency */
+ for (i = 0; i < REFCLK_LUT_SIZE; i++)
+ if (refclk_lut[i] == refclk_rate)
+ break;
+
+ regmap_write(pdata->regmap, SN_REFCLK_FREQ_REG,
+ (refclk_src | (i << SN_DSIA_REFCLK_OFFSET)));
+}
+
+/**
+ * LUT index corresponds to register value and
+ * LUT values corresponds to dp data rate supported
+ * by the bridge in Mbps unit.
+ */
+static const unsigned int ti_sn_bridge_dp_rate_lut[] = {
+ 0, 1620, 2160, 2430, 2700, 3240, 4320, 5400
+};
+
+static void ti_sn_bridge_set_dsi_dp_rate(struct ti_sn_bridge *pdata)
+{
+ unsigned int bit_rate_mhz, clk_freq_mhz, dp_rate_mhz;
+ unsigned int val = 0, i = 0;
+ struct drm_display_mode *mode =
+ &pdata->bridge.encoder->crtc->state->adjusted_mode;
+
+ /* set DSIA clk frequency */
+ bit_rate_mhz = (mode->clock / 1000) *
+ mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
+ clk_freq_mhz = bit_rate_mhz / (pdata->dsi->lanes * 2);
+
+ /* for each increment in val, frequency increases by 5MHz */
+ val = (MIN_DSI_CLK_FREQ_MHZ / 5) +
+ (((clk_freq_mhz - MIN_DSI_CLK_FREQ_MHZ) / 5) & 0xFF);
+ regmap_write(pdata->regmap, SN_DSIA_CLK_FREQ_REG, val);
+
+ /* set DP data rate */
+ dp_rate_mhz = ((bit_rate_mhz / pdata->dsi->lanes) * DP_CLK_FUDGE_NUM) /
+ DP_CLK_FUDGE_DEN;
+ for (i = 0; i < ARRAY_SIZE(ti_sn_bridge_dp_rate_lut) - 1; i++)
+ if (ti_sn_bridge_dp_rate_lut[i] > dp_rate_mhz)
+ break;
+
+ regmap_update_bits(pdata->regmap, SN_DATARATE_CONFIG_REG,
+ SN_DP_DATA_RATE_BITS, i << SN_DP_DATA_RATE_OFFSET);
+}
+
+static void ti_sn_bridge_set_video_timings(struct ti_sn_bridge *pdata)
+{
+ struct drm_display_mode *mode =
+ &pdata->bridge.encoder->crtc->state->adjusted_mode;
+
+ ti_sn_bridge_write_u16(pdata, SN_CHA_ACTIVE_LINE_LENGTH_LOW_REG,
+ mode->hdisplay);
+ ti_sn_bridge_write_u16(pdata, SN_CHA_VERTICAL_DISPLAY_SIZE_LOW_REG,
+ mode->vdisplay);
+ ti_sn_bridge_write_u16(pdata, SN_CHA_HSYNC_PULSE_WIDTH_LOW_REG,
+ mode->hsync_end - mode->hsync_start);
+ ti_sn_bridge_write_u16(pdata, SN_CHA_VSYNC_PULSE_WIDTH_LOW_REG,
+ mode->vsync_end - mode->vsync_start);
+
+ regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_BACK_PORCH_REG,
+ (mode->htotal - mode->hsync_end) & 0xFF);
+ regmap_write(pdata->regmap, SN_CHA_VERTICAL_BACK_PORCH_REG,
+ (mode->vtotal - mode->vsync_end) & 0xFF);
+
+ regmap_write(pdata->regmap, SN_CHA_HORIZONTAL_FRONT_PORCH_REG,
+ (mode->hsync_start - mode->hdisplay) & 0xFF);
+ regmap_write(pdata->regmap, SN_CHA_VERTICAL_FRONT_PORCH_REG,
+ (mode->vsync_start - mode->vdisplay) & 0xFF);
+
+ usleep_range(10000, 10500); /* 10ms delay recommended by spec */
+}
+
+static void ti_sn_bridge_enable(struct drm_bridge *bridge)
+{
+ struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
+ unsigned int val = 0;
+
+ if (pdata->panel) {
+ drm_panel_prepare(pdata->panel);
+ /* in case drm_panel is connected then HPD is not supported */
+ regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG,
+ SN_HPD_DISABLE_BIT, !0);
+ }
+
+ /* DSI_A lane config */
+ val = (4 - pdata->dsi->lanes) << SN_DSIA_LANE_OFFSET;
+ regmap_update_bits(pdata->regmap, SN_DSI_LANES_REG,
+ SN_DSIA_NUM_LANES_BITS, val);
+
+ /* DP lane config */
+ val = (pdata->dsi->lanes - 1) << SN_DP_LANE_OFFSET;
+ regmap_update_bits(pdata->regmap, SN_SSC_CONFIG_REG,
+ SN_DP_NUM_LANES_BITS, val);
+
+ /* set dsi/dp clk frequency value */
+ ti_sn_bridge_set_dsi_dp_rate(pdata);
+
+ /* enable DP PLL */
+ regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
+ usleep_range(10000, 10500); /* 10ms delay recommended by spec */
+
+ /**
+ * The SN65DSI86 only supports ASSR Display Authentication method and
+ * this method is enabled by default. An eDP panel must support this
+ * authentication method. We need to enable this method in the eDP panel
+ * at DisplayPort address 0x0010A prior to link training.
+ */
+ regmap_write(pdata->regmap, SN_AUX_WDATA0_REG, 0x01);
+ regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, 0x00);
+ regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG, 0x01);
+ regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, 0x0A);
+ regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, 0x01);
+ regmap_write(pdata->regmap, SN_AUX_CMD_REG, 0x81);
+ usleep_range(10000, 10500); /* 10ms delay recommended by spec */
+
+ /* Semi auto link training mode */
+ regmap_write(pdata->regmap, SN_ML_TX_MODE_REG, 0x0A);
+ msleep(20); /* 20ms delay recommended by spec */
+
+ /* config video parameters */
+ ti_sn_bridge_set_video_timings(pdata);
+
+ /* enable video stream */
+ regmap_update_bits(pdata->regmap, SN_ENH_FRAME_REG,
+ SN_ENABLE_VID_STREAM_BIT, SN_ENABLE_VID_STREAM_BIT);
+
+ if (pdata->panel)
+ drm_panel_enable(pdata->panel);
+}
+
+static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
+{
+ struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
+
+ pm_runtime_get_sync(pdata->dev);
+
+ /* configure bridge CLK_SRC and ref_clk */
+ ti_sn_bridge_set_refclk(pdata);
+}
+
+static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
+{
+ struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
+
+ if (pdata->refclk)
+ clk_disable_unprepare(pdata->refclk);
+
+ pm_runtime_put_sync(pdata->dev);
+}
+
+static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
+ .attach = ti_sn_bridge_attach,
+ .pre_enable = ti_sn_bridge_pre_enable,
+ .enable = ti_sn_bridge_enable,
+ .disable = ti_sn_bridge_disable,
+ .post_disable = ti_sn_bridge_post_disable,
+};
+
+static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)
+{
+ struct device_node *np = pdata->dev->of_node;
+
+ pdata->host_node = of_graph_get_remote_node(np, 0, 0);
+
+ if (!pdata->host_node) {
+ DRM_ERROR("remote dsi host node not found\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int ti_sn_bridge_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ti_sn_bridge *pdata;
+ struct device_node *ddc_node;
+ struct mipi_dsi_host *host;
+ struct mipi_dsi_device *dsi;
+ int ret = 0;
+ const struct mipi_dsi_device_info info = { .type = "ti_sn_bridge",
+ .channel = 0,
+ .node = NULL,
+ };
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ DRM_ERROR("device doesn't support I2C\n");
+ return -ENODEV;
+ }
+
+ pdata = devm_kzalloc(&client->dev, sizeof(struct ti_sn_bridge),
+ GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->regmap = devm_regmap_init_i2c(client,
+ &ti_sn_bridge_regmap_config);
+ if (IS_ERR(pdata->regmap)) {
+ DRM_ERROR("regmap i2c init failed\n");
+ return PTR_ERR(pdata->regmap);
+ }
+
+ pdata->dev = &client->dev;
+ dev_set_drvdata(&client->dev, pdata);
+
+ pdata->enable_gpio = devm_gpiod_get(pdata->dev, "enable",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(pdata->enable_gpio)) {
+ DRM_ERROR("failed to get enable gpio from DT\n");
+ ret = PTR_ERR(pdata->enable_gpio);
+ return ret;
+ }
+
+ ret = ti_sn_bridge_parse_regulators(pdata);
+ if (ret) {
+ DRM_ERROR("failed to parse regulators\n");
+ return ret;
+ }
+
+ ret = drm_of_find_panel_or_bridge(pdata->dev->of_node, 1, 0,
+ &pdata->panel, NULL);
+ if (ret) {
+ DRM_ERROR("could not find any drm panel node\n");
+ return ret;
+ }
+
+ ret = ti_sn_bridge_parse_dsi_host(pdata);
+ if (ret)
+ return ret;
+
+ host = of_find_mipi_dsi_host_by_node(pdata->host_node);
+ if (!host) {
+ DRM_ERROR("failed to find dsi host\n");
+ ret = -EPROBE_DEFER;
+ goto err_dsi_host;
+ }
+
+ dsi = mipi_dsi_device_register_full(host, &info);
+ if (IS_ERR(dsi)) {
+ DRM_ERROR("failed to create dsi device\n");
+ ret = PTR_ERR(dsi);
+ goto err_dsi_host;
+ }
+
+ /* TODO: setting to 4 lanes always for now */
+ dsi->lanes = 4;
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+ MIPI_DSI_MODE_EOT_PACKET | MIPI_DSI_MODE_VIDEO_HSE;
+
+ ret = mipi_dsi_attach(dsi);
+ if (ret < 0) {
+ DRM_ERROR("failed to attach dsi to host\n");
+ goto err_dsi_attach;
+ }
+ pdata->dsi = dsi;
+
+ pdata->refclk = devm_clk_get(pdata->dev, "refclk");
+
+ ddc_node = of_parse_phandle(pdata->dev->of_node, "ddc-i2c-bus", 0);
+ if (ddc_node) {
+ pdata->ddc = of_find_i2c_adapter_by_node(ddc_node);
+ of_node_put(ddc_node);
+ if (!pdata->ddc) {
+ DRM_DEBUG_KMS("failed to read ddc node\n");
+ ret = -EPROBE_DEFER;
+ goto err_dsi_attach;
+ }
+ } else {
+ DRM_DEBUG_KMS("no ddc property found\n");
+ }
+
+ pm_runtime_enable(pdata->dev);
+
+ i2c_set_clientdata(client, pdata);
+
+ pdata->bridge.funcs = &ti_sn_bridge_funcs;
+ pdata->bridge.of_node = client->dev.of_node;
+
+ drm_bridge_add(&pdata->bridge);
+
+ return 0;
+
+err_dsi_attach:
+ mipi_dsi_device_unregister(dsi);
+err_dsi_host:
+ of_node_put(pdata->host_node);
+ return ret;
+}
+
+static int ti_sn_bridge_remove(struct i2c_client *client)
+{
+ struct ti_sn_bridge *pdata = i2c_get_clientdata(client);
+
+ if (!pdata)
+ return -EINVAL;
+
+ if (pdata->host_node)
+ of_node_put(pdata->host_node);
+
+ mipi_dsi_detach(pdata->dsi);
+ mipi_dsi_device_unregister(pdata->dsi);
+
+ drm_bridge_remove(&pdata->bridge);
+ pm_runtime_disable(pdata->dev);
+ i2c_put_adapter(pdata->ddc);
+
+ return 0;
+}
+
+static struct i2c_device_id ti_sn_bridge_id[] = {
+ { "ti,sn65dsi86", 0},
+ {},
+};
+MODULE_DEVICE_TABLE(i2c, ti_sn_bridge_id);
+
+static const struct of_device_id ti_sn_bridge_match_table[] = {
+ {.compatible = "ti,sn65dsi86"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, ti_sn_bridge_match_table);
+
+static struct i2c_driver ti_sn_bridge_driver = {
+ .driver = {
+ .name = "ti_sn65dsi86",
+ .of_match_table = ti_sn_bridge_match_table,
+ .pm = &ti_sn_bridge_pm_ops,
+ },
+ .probe = ti_sn_bridge_probe,
+ .remove = ti_sn_bridge_remove,
+ .id_table = ti_sn_bridge_id,
+};
+
+module_i2c_driver(ti_sn_bridge_driver);
+MODULE_DESCRIPTION("sn65dsi86 DSI to eDP bridge driver");
+MODULE_LICENSE("GPL v2");
--
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