The tmds181 and sn65dp159 are "retimers" and hence can be considered HDMI-to-HDMI bridges. Typical usage is to convert the output of an FPGA into a valid HDMI signal, and it will typically be inserted between an encoder and hdmi-connector.
Signed-off-by: Mike Looijmans <mike.looijm...@topic.nl> --- Changes in v2: Use atomic_enable/disable Use #defines for bit fields in registers Allow HDMI 2 compliance Filter modes on clock range Use cross-over pixel frequency instead of manual overides Devicetree bindings according to standards drivers/gpu/drm/bridge/Kconfig | 11 + drivers/gpu/drm/bridge/Makefile | 1 + drivers/gpu/drm/bridge/ti-tmds181.c | 561 ++++++++++++++++++++++++++++ 3 files changed, 573 insertions(+) create mode 100644 drivers/gpu/drm/bridge/ti-tmds181.c diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index b9e0ca85226a..753177fc9b50 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -430,6 +430,17 @@ config DRM_TI_SN65DSI86 help Texas Instruments SN65DSI86 DSI to eDP Bridge driver +config DRM_TI_TMDS181 + tristate "TI TMDS181 and SN65DP159 HDMI retimer bridge driver" + depends on OF + select DRM_KMS_HELPER + select REGMAP_I2C + help + Enable this to support the TI TMDS181 and SN65DP159 HDMI retimers. + The SN65DP159 provides output into a cable (source) whereas the + TMDS181 is meant to forward a cable signal into a PCB (sink). Either + can be set up as source or sink though. + config DRM_TI_TPD12S015 tristate "TI TPD12S015 HDMI level shifter and ESD protection" depends on OF diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 245e8a27e3fc..f4b5089e903c 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_DRM_TI_SN65DSI83) += ti-sn65dsi83.o obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o obj-$(CONFIG_DRM_TI_TDP158) += ti-tdp158.o obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o +obj-$(CONFIG_DRM_TI_TMDS181) += ti-tmds181.o obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o obj-$(CONFIG_DRM_ITE_IT66121) += ite-it66121.o diff --git a/drivers/gpu/drm/bridge/ti-tmds181.c b/drivers/gpu/drm/bridge/ti-tmds181.c new file mode 100644 index 000000000000..34cbdb066820 --- /dev/null +++ b/drivers/gpu/drm/bridge/ti-tmds181.c @@ -0,0 +1,561 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TI tmds181 and sn65dp159 HDMI redriver and retimer chips + * + * Copyright (C) 2018 - 2025 Topic Embedded Products <www.topic.nl> + * + * based on code + * Copyright (C) 2007 Hans Verkuil + * Copyright (C) 2016, 2017 Leon Woestenberg <l...@sidebranch.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <linux/gpio/consumer.h> +#include <linux/delay.h> + +#include <drm/drm_atomic_helper.h> +#include <drm/drm_bridge.h> +#include <drm/drm_crtc.h> +#include <drm/drm_print.h> +#include <drm/drm_probe_helper.h> + +MODULE_DESCRIPTION("I2C device driver for DP159 and TMDS181 redriver/retimer"); +MODULE_AUTHOR("Mike Looijmans"); +MODULE_LICENSE("GPL"); + +#define TMDS181_REG_ID 0 +#define TMDS181_REG_REV 0x8 +#define TMDS181_REG_CTRL9 0x9 +/* Registers A and B have a volatile bit, but we don't use it, so cache is ok */ +#define TMDS181_REG_CTRLA 0xA +#define TMDS181_REG_CTRLB 0xB +#define TMDS181_REG_CTRLC 0xC +#define TMDS181_REG_EQUALIZER 0xD +#define TMDS181_REG_EYESCAN 0xE + +#define TMDS181_CTRL9_SIG_EN BIT(4) +#define TMDS181_CTRL9_PD_EN BIT(3) +#define TMDS181_CTRL9_HPD_AUTO_PWRDWN_DISABLE BIT(2) +#define TMDS181_CTRL9_I2C_DR_CTL GENMASK(1, 0) + +#define TMDS181_CTRLA_MODE_SINK BIT(7) +#define TMDS181_CTRLA_HPDSNK_GATE_EN BIT(6) +#define TMDS181_CTRLA_EQ_ADA_EN BIT(5) +#define TMDS181_CTRLA_EQ_EN BIT(4) +#define TMDS181_CTRLA_AUX_BRG_EN BIT(3) +#define TMDS181_CTRLA_APPLY BIT(2) +#define TMDS181_CTRLA_DEV_FUNC_MODE GENMASK(1, 0) + +#define TMDS181_CTRLB_SLEW_CTL GENMASK(7, 6) +#define TMDS181_CTRLB_HDMI_SEL_DVI BIT(5) +#define TMDS181_CTRLB_TX_TERM_CTL GENMASK(4, 3) +#define TMDS181_CTRLB_DDC_DR_SEL BIT(2) +#define TMDS181_CTRLB_TMDS_CLOCK_RATIO_STATUS BIT(1) +#define TMDS181_CTRLB_DDC_TRAIN_SET BIT(0) + +#define TMDS181_CTRLB_TX_TERM_150_300_OHMS 1 +#define TMDS181_CTRLB_TX_TERM_75_150_OHMS 3 + +#define TMDS181_CTRLC_VSWING_DATA GENMASK(7, 5) +#define TMDS181_CTRLC_VSWING_CLK GENMASK(4, 2) +#define TMDS181_CTRLC_HDMI_TWPST1 GENMASK(1, 0) + +#define TMDS181_EQ_DATA_LANE GENMASK(5, 3) +#define TMDS181_EQ_CLOCK_LANE GENMASK(2, 1) +#define TMDS181_EQ_DIS_HDMI2_SWG BIT(0) + +/* Above this data rate HDMI2 standards apply (TX termination) */ +#define HDMI2_PIXEL_RATE_KHZ 340000 + +enum tmds181_chip { + tmds181, + dp159, +}; + +struct tmds181_data { + struct i2c_client *client; + struct regmap *regmap; + struct drm_bridge *next_bridge; + struct drm_bridge bridge; + u32 retimer_threshold_khz; + enum tmds181_chip chip; +}; + +static inline struct tmds181_data * +drm_bridge_to_tmds181_data(struct drm_bridge *bridge) +{ + return container_of(bridge, struct tmds181_data, bridge); +} + +/* Set "apply" bit in control register after making changes */ +static int tmds181_apply_changes(struct tmds181_data *data) +{ + return regmap_write_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_APPLY, TMDS181_CTRLA_APPLY); +} + +static int tmds181_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct tmds181_data *data = drm_bridge_to_tmds181_data(bridge); + + return drm_bridge_attach(bridge->encoder, data->next_bridge, bridge, + flags); +} + +static enum drm_mode_status +tmds181_mode_valid(struct drm_bridge *bridge, const struct drm_display_info *info, + const struct drm_display_mode *mode) +{ + /* Clock limits: clk between 25 and 350 MHz, clk is 1/10 of bit clock */ + if (mode->clock < 25000) + return MODE_CLOCK_LOW; + + /* The actual HDMI clock (if provided) cannot exceed 350MHz */ + if (mode->crtc_clock > 350000) + return MODE_CLOCK_HIGH; + + /* + * When in HDMI 2 mode, the clock is 1/40th of the bitrate. The limit is + * then the data rate of 6Gbps, which would use a 600MHz pixel clock. + */ + if (mode->clock > 600000) + return MODE_CLOCK_HIGH; + + return MODE_OK; +} + +static void tmds181_enable(struct drm_bridge *bridge, struct drm_bridge_state *old_bridge_state) +{ + struct tmds181_data *data = drm_bridge_to_tmds181_data(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; + unsigned int val; + + /* + * 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; + + /* Set retimer/redriver mode based on pixel clock */ + val = mode->clock > data->retimer_threshold_khz ? TMDS181_CTRLA_DEV_FUNC_MODE : 0; + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_DEV_FUNC_MODE, val); + + /* Configure TX termination based on pixel clock */ + val = mode->clock > HDMI2_PIXEL_RATE_KHZ ? + TMDS181_CTRLB_TX_TERM_75_150_OHMS : + TMDS181_CTRLB_TX_TERM_150_300_OHMS; + regmap_update_bits(data->regmap, TMDS181_REG_CTRLB, + TMDS181_CTRLB_TX_TERM_CTL, + FIELD_PREP(TMDS181_CTRLB_TX_TERM_CTL, val)); + + regmap_update_bits(data->regmap, TMDS181_REG_CTRL9, + TMDS181_CTRL9_PD_EN, 0); +} + +static void tmds181_disable(struct drm_bridge *bridge, struct drm_bridge_state *old_bridge_state) +{ + struct tmds181_data *data = drm_bridge_to_tmds181_data(bridge); + + /* Set the PD_EN bit */ + regmap_update_bits(data->regmap, TMDS181_REG_CTRL9, + TMDS181_CTRL9_PD_EN, TMDS181_CTRL9_PD_EN); +} + +static const struct drm_bridge_funcs tmds181_bridge_funcs = { + .attach = tmds181_attach, + .mode_valid = tmds181_mode_valid, + .atomic_enable = tmds181_enable, + .atomic_disable = tmds181_disable, + + .atomic_reset = drm_atomic_helper_bridge_reset, + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, +}; + +static const char * const tmds181_modes[] = { + "redriver", + "auto1", + "auto2", + "retimer", +}; + +static ssize_t mode_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct tmds181_data *data = dev_get_drvdata(dev); + const char *equalizer; + u32 val; + int ret; + + ret = regmap_read(data->regmap, TMDS181_REG_CTRLA, &val); + if (ret < 0) + return ret; + + if (val & BIT(4)) { + if (val & BIT(5)) + equalizer = "eq-adaptive"; + else + equalizer = "eq-fixed"; + } else { + equalizer = "eq-disabled"; + } + + return scnprintf(buf, PAGE_SIZE, "%6s %s %s\n", + (val & BIT(7)) ? "sink" : "source", + tmds181_modes[val & 0x03], + equalizer); +} + +static ssize_t mode_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct tmds181_data *data = dev_get_drvdata(dev); + u32 val; + int ret; + int i; + + /* Strip trailing newline(s) for being user friendly */ + while (len && buf[len] == '\n') + --len; + + /* Need at least 4 actual characters */ + if (len < 4) + return -EINVAL; + + ret = regmap_read(data->regmap, TMDS181_REG_CTRLA, &val); + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(tmds181_modes); ++i) { + if (strncmp(tmds181_modes[i], buf, len) == 0) { + val &= ~TMDS181_CTRLA_DEV_FUNC_MODE; + val |= FIELD_PREP(TMDS181_CTRLA_DEV_FUNC_MODE, i); + break; + } + } + + if (strncmp("sink", buf, len) == 0) + val |= TMDS181_CTRLA_MODE_SINK; + + if (strncmp("source", buf, len) == 0) + val &= ~TMDS181_CTRLA_MODE_SINK; + + if (strncmp("eq-", buf, 3) == 0) { + switch (buf[3]) { + case 'a': /* adaptive */ + val |= TMDS181_CTRLA_EQ_ADA_EN | TMDS181_CTRLA_EQ_EN; + break; + case 'f': /* fixed */ + val |= TMDS181_CTRLA_EQ_EN; + val &= ~TMDS181_CTRLA_EQ_ADA_EN; + break; + case 'd': /* disable */ + val &= ~(TMDS181_CTRLA_EQ_ADA_EN | TMDS181_CTRLA_EQ_EN); + break; + } + } + + /* Always set the "apply changes" bit */ + val |= TMDS181_CTRLA_APPLY; + + ret = regmap_write(data->regmap, TMDS181_REG_CTRLA, val); + if (ret < 0) + return ret; + + return len; +} + +/* termination for HDMI TX: 0=off, 1=150..300, 3=75..150 ohms */ +static ssize_t termination_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tmds181_data *data = dev_get_drvdata(dev); + u32 val; + int ret; + + ret = regmap_read(data->regmap, TMDS181_REG_CTRLB, &val); + if (ret < 0) + return ret; + + return scnprintf(buf, PAGE_SIZE, "%u\n", + FIELD_GET(TMDS181_CTRLB_TX_TERM_CTL, val)); +} + +static ssize_t termination_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct tmds181_data *data = dev_get_drvdata(dev); + u32 val; + unsigned long newval; + int ret; + + ret = regmap_read(data->regmap, TMDS181_REG_CTRLB, &val); + if (ret < 0) + return ret; + + ret = kstrtoul((const char *) buf, 10, &newval); + if (ret) + return ret; + + if (newval > 3) + return -EINVAL; + + val &= ~TMDS181_CTRLB_TX_TERM_CTL; + val |= FIELD_PREP(TMDS181_CTRLB_TX_TERM_CTL, newval); + + ret = regmap_write(data->regmap, TMDS181_REG_CTRLB, val); + if (ret < 0) + return ret; + + return len; +} + +static DEVICE_ATTR_RW(mode); +static DEVICE_ATTR_RW(termination); + +static struct attribute *tmds181_attrs[] = { + &dev_attr_mode.attr, + &dev_attr_termination.attr, + NULL, +}; + +static const struct attribute_group tmds181_attr_group = { + .attrs = tmds181_attrs, +}; + +static const u8 tmds181_id_tmds181[8] __nonstring = "TMDS181 "; +static const u8 tmds181_id_dp159[8] __nonstring = "DP159 "; + +static int tmds181_check_id(struct tmds181_data *data) +{ + int ret; + int retry; + u8 buffer[8]; + + for (retry = 0; retry < 20; ++retry) { + ret = regmap_bulk_read(data->regmap, TMDS181_REG_ID, buffer, + sizeof(buffer)); + if (!ret) + break; + + /* Compensate for very long OE power-up delays due to the cap */ + usleep_range(5000, 10000); + } + + if (ret) { + dev_err(&data->client->dev, "I2C read ID failed\n"); + return ret; + } + + if (memcmp(buffer, tmds181_id_tmds181, sizeof(buffer)) == 0) { + dev_info(&data->client->dev, "Detected: TMDS181\n"); + data->chip = tmds181; + return 0; + } + + if (memcmp(buffer, tmds181_id_dp159, sizeof(buffer)) == 0) { + dev_info(&data->client->dev, "Detected: DP159\n"); + data->chip = dp159; + return 0; + } + + dev_err(&data->client->dev, "Unknown ID: %*pE\n", (int)sizeof(buffer), buffer); + + return -ENODEV; +} + +static bool tmds181_regmap_is_volatile(struct device *dev, unsigned int reg) +{ + switch (reg) { + /* IBERT result and status registers, not used yet */ + case 0x15: + case 0x17 ... 0x1F: + return true; + default: + return false; + } +} + +static const struct regmap_config tmds181_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .cache_type = REGCACHE_RBTREE, + .max_register = 0x20, + .volatile_reg = tmds181_regmap_is_volatile, +}; + +static int tmds181_probe(struct i2c_client *client) +{ + struct tmds181_data *data; + struct gpio_desc *oe_gpio; + int ret; + u32 param; + u8 val; + + /* Check if the adapter supports the needed features */ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) + return -EIO; + + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + i2c_set_clientdata(client, data); + data->regmap = devm_regmap_init_i2c(client, &tmds181_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + + /* The "OE" pin acts as a reset */ + oe_gpio = devm_gpiod_get_optional(&client->dev, "oe", GPIOD_OUT_LOW); + if (IS_ERR(oe_gpio)) { + ret = PTR_ERR(oe_gpio); + if (ret != -EPROBE_DEFER) + dev_err(&client->dev, "failed to acquire 'oe' gpio\n"); + return ret; + } + if (oe_gpio) { + /* Need at least 100us reset pulse */ + usleep_range(100, 200); + gpiod_set_value_cansleep(oe_gpio, 1); + } + + /* Reading the ID also provides enough time for the reset */ + ret = tmds181_check_id(data); + if (ret) + return ret; + + /* + * We take care of power control, so disable the chips PM functions, and + * allow the DDC to run at 400kHz + */ + regmap_update_bits(data->regmap, TMDS181_REG_CTRL9, + TMDS181_CTRL9_SIG_EN | TMDS181_CTRL9_PD_EN | + TMDS181_CTRL9_HPD_AUTO_PWRDWN_DISABLE | + TMDS181_CTRL9_I2C_DR_CTL, + TMDS181_CTRL9_PD_EN | + TMDS181_CTRL9_HPD_AUTO_PWRDWN_DISABLE | + TMDS181_CTRL9_I2C_DR_CTL); + + /* Apply configuration changes */ + if (of_property_read_bool(client->dev.of_node, "source-mode")) + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_MODE_SINK, 0); + if (of_property_read_bool(client->dev.of_node, "sink-mode")) + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_MODE_SINK, TMDS181_CTRLA_MODE_SINK); + + /* + * Using the automatic modes of the chip uses considerable power as it + * will keep the PLL running at all times. So instead, define our own + * threshold for the pixel rate. This also allows to use a sane default + * of 200MHz pixel rate for the redriver-retimer crossover point, as the + * modes below 3k don't show any benefit from the retimer. + */ + data->retimer_threshold_khz = 200000; + if (!of_property_read_u32(client->dev.of_node, + "ti,retimer-threshold-hz", ¶m)) + data->retimer_threshold_khz = param / 1000; + + /* Default to low-power redriver mode */ + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_DEV_FUNC_MODE, 0x00); + + if (of_property_read_bool(client->dev.of_node, "ti,adaptive-equalizer")) + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_EQ_EN | TMDS181_CTRLA_EQ_ADA_EN, + TMDS181_CTRLA_EQ_EN | TMDS181_CTRLA_EQ_ADA_EN); + if (of_property_read_bool(client->dev.of_node, "ti,disable-equalizer")) + regmap_update_bits(data->regmap, TMDS181_REG_CTRLA, + TMDS181_CTRLA_EQ_EN | TMDS181_CTRLA_EQ_ADA_EN, + 0); + + switch (data->chip) { + case dp159: + val = 0; + if (!of_property_read_u32(client->dev.of_node, + "slew-rate", ¶m)) { + if (param > 3) { + dev_err(&client->dev, "invalid slew-rate\n"); + return -EINVAL; + } + /* Implement 0 = slow, 3 = fast slew rate */ + val = FIELD_PREP(TMDS181_CTRLB_SLEW_CTL, (3 - param)); + } + if (of_property_read_bool(client->dev.of_node, "ti,dvi-mode")) + val |= TMDS181_CTRLB_HDMI_SEL_DVI; + break; + default: + val = TMDS181_CTRLB_DDC_DR_SEL; + break; + } + + /* Default to low-speed termination */ + val |= FIELD_PREP(TMDS181_CTRLB_TX_TERM_CTL, TMDS181_CTRLB_TX_TERM_150_300_OHMS); + + ret = regmap_write(data->regmap, TMDS181_REG_CTRLB, val); + if (ret < 0) { + dev_err(&client->dev, "regmap_write(B) failed\n"); + return ret; + } + + ret = sysfs_create_group(&client->dev.kobj, &tmds181_attr_group); + if (ret) + dev_err(&client->dev, "sysfs_create_group error: %d\n", ret); + + /* Find next bridge in chain */ + data->next_bridge = devm_drm_of_get_bridge(&client->dev, client->dev.of_node, 1, 0); + if (IS_ERR(data->next_bridge)) + return dev_err_probe(&client->dev, PTR_ERR(data->next_bridge), + "Failed to find next bridge\n"); + + /* Register the bridge. */ + data->bridge.funcs = &tmds181_bridge_funcs; + data->bridge.of_node = client->dev.of_node; + + return devm_drm_bridge_add(&client->dev, &data->bridge); +} + +static const struct i2c_device_id tmds181_id[] = { + { "tmds181", tmds181 }, + { "sn65dp159", dp159 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, tmds181_id); + +#if IS_ENABLED(CONFIG_OF) +static const struct of_device_id tmds181_of_match[] = { + { .compatible = "ti,tmds181", }, + { .compatible = "ti,sn65dp159", }, + {} +}; +MODULE_DEVICE_TABLE(of, tmds181_of_match); +#endif + +static struct i2c_driver tmds181_driver = { + .driver = { + .owner = THIS_MODULE, + .name = "tmds181", + .of_match_table = of_match_ptr(tmds181_of_match), + }, + .probe = tmds181_probe, + .id_table = tmds181_id, +}; + +module_i2c_driver(tmds181_driver); -- 2.43.0 Met vriendelijke groet / kind regards, Mike Looijmans System Expert TOPIC Embedded Products B.V. Materiaalweg 4, 5681 RJ Best The Netherlands T: +31 (0) 499 33 69 69 E: mike.looijm...@topic.nl W: www.topic.nl Please consider the environment before printing this e-mail