From bc001cd1a48240c388804b3e438ae3e1c1a5bb48 Mon Sep 17 00:00:00 2001 From: Franz Schnyder Date: Fri, 6 Feb 2026 13:37:36 +0100 Subject: drm/bridge: ti-sn65dsi86: Enable HPD polling if IRQ is not used commit 0b87d51690dd5131cbe9fbd23746b037aab89815 upstream. Fallback to polling to detect hotplug events on systems without interrupts. On systems where the interrupt line of the bridge is not connected, the bridge cannot notify hotplug events. Only add the DRM_BRIDGE_OP_HPD flag if an interrupt has been registered otherwise remain in polling mode. Fixes: 55e8ff842051 ("drm/bridge: ti-sn65dsi86: Add HPD for DisplayPort connector type") Cc: stable@vger.kernel.org # 6.16: 9133bc3f0564: drm/bridge: ti-sn65dsi86: Add Signed-off-by: Franz Schnyder Reviewed-by: Douglas Anderson [dianders: Adjusted Fixes/stable line based on discussion] Signed-off-by: Douglas Anderson Link: https://patch.msgid.link/20260206123758.374555-1-fra.schnyder@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/bridge/ti-sn65dsi86.c') diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index ae0d08e5e960..c136ef7d4c85 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -1314,6 +1314,7 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev, { struct ti_sn65dsi86 *pdata = dev_get_drvdata(adev->dev.parent); struct device_node *np = pdata->dev->of_node; + const struct i2c_client *client = to_i2c_client(pdata->dev); int ret; pdata->next_bridge = devm_drm_of_get_bridge(&adev->dev, np, 1, 0); @@ -1332,8 +1333,9 @@ static int ti_sn_bridge_probe(struct auxiliary_device *adev, ? DRM_MODE_CONNECTOR_DisplayPort : DRM_MODE_CONNECTOR_eDP; if (pdata->bridge.type == DRM_MODE_CONNECTOR_DisplayPort) { - pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT | - DRM_BRIDGE_OP_HPD; + pdata->bridge.ops = DRM_BRIDGE_OP_EDID | DRM_BRIDGE_OP_DETECT; + if (client->irq) + pdata->bridge.ops |= DRM_BRIDGE_OP_HPD; /* * If comms were already enabled they would have been enabled * with the wrong value of HPD_DISABLE. Update it now. Comms -- cgit v1.2.3 From 9fd37b636bc2dc680ffcee0e1edea908b8b6ee7c Mon Sep 17 00:00:00 2001 From: John Ripple Date: Mon, 15 Sep 2025 11:45:43 -0600 Subject: drm/bridge: ti-sn65dsi86: Add support for DisplayPort mode with HPD commit 9133bc3f0564890218cbba6cc7e81ebc0841a6f1 upstream. Add support for DisplayPort to the bridge, which entails the following: - Get and use an interrupt for HPD; - Properly clear all status bits in the interrupt handler; Signed-off-by: John Ripple Reviewed-by: Douglas Anderson Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20250915174543.2564994-1-john.ripple@keysight.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 112 ++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) (limited to 'drivers/gpu/drm/bridge/ti-sn65dsi86.c') diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index c136ef7d4c85..98d64ad791d0 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -106,10 +106,21 @@ #define SN_PWM_EN_INV_REG 0xA5 #define SN_PWM_INV_MASK BIT(0) #define SN_PWM_EN_MASK BIT(1) + +#define SN_IRQ_EN_REG 0xE0 +#define IRQ_EN BIT(0) + +#define SN_IRQ_EVENTS_EN_REG 0xE6 +#define HPD_INSERTION_EN BIT(1) +#define HPD_REMOVAL_EN BIT(2) + #define SN_AUX_CMD_STATUS_REG 0xF4 #define AUX_IRQ_STATUS_AUX_RPLY_TOUT BIT(3) #define AUX_IRQ_STATUS_AUX_SHORT BIT(5) #define AUX_IRQ_STATUS_NAT_I2C_FAIL BIT(6) +#define SN_IRQ_STATUS_REG 0xF5 +#define HPD_REMOVAL_STATUS BIT(2) +#define HPD_INSERTION_STATUS BIT(1) #define MIN_DSI_CLK_FREQ_MHZ 40 @@ -152,7 +163,9 @@ * @ln_assign: Value to program to the LN_ASSIGN register. * @ln_polrs: Value for the 4-bit LN_POLRS field of SN_ENH_FRAME_REG. * @comms_enabled: If true then communication over the aux channel is enabled. + * @hpd_enabled: If true then HPD events are enabled. * @comms_mutex: Protects modification of comms_enabled. + * @hpd_mutex: Protects modification of hpd_enabled. * * @gchip: If we expose our GPIOs, this is used. * @gchip_output: A cache of whether we've set GPIOs to output. This @@ -190,7 +203,9 @@ struct ti_sn65dsi86 { u8 ln_assign; u8 ln_polrs; bool comms_enabled; + bool hpd_enabled; struct mutex comms_mutex; + struct mutex hpd_mutex; #if defined(CONFIG_OF_GPIO) struct gpio_chip gchip; @@ -221,6 +236,23 @@ static const struct regmap_config ti_sn65dsi86_regmap_config = { .max_register = 0xFF, }; +static int ti_sn65dsi86_read_u8(struct ti_sn65dsi86 *pdata, unsigned int reg, + u8 *val) +{ + int ret; + unsigned int reg_val; + + ret = regmap_read(pdata->regmap, reg, ®_val); + if (ret) { + dev_err(pdata->dev, "fail to read raw reg %#x: %d\n", + reg, ret); + return ret; + } + *val = (u8)reg_val; + + return 0; +} + static int __maybe_unused ti_sn65dsi86_read_u16(struct ti_sn65dsi86 *pdata, unsigned int reg, u16 *val) { @@ -379,6 +411,7 @@ static void ti_sn65dsi86_disable_comms(struct ti_sn65dsi86 *pdata) static int __maybe_unused ti_sn65dsi86_resume(struct device *dev) { struct ti_sn65dsi86 *pdata = dev_get_drvdata(dev); + const struct i2c_client *client = to_i2c_client(pdata->dev); int ret; ret = regulator_bulk_enable(SN_REGULATOR_SUPPLY_NUM, pdata->supplies); @@ -413,6 +446,13 @@ static int __maybe_unused ti_sn65dsi86_resume(struct device *dev) if (pdata->refclk) ti_sn65dsi86_enable_comms(pdata, NULL); + if (client->irq) { + ret = regmap_update_bits(pdata->regmap, SN_IRQ_EN_REG, IRQ_EN, + IRQ_EN); + if (ret) + dev_err(pdata->dev, "Failed to enable IRQ events: %d\n", ret); + } + return ret; } @@ -1211,6 +1251,8 @@ static void ti_sn65dsi86_debugfs_init(struct drm_bridge *bridge, struct dentry * static void ti_sn_bridge_hpd_enable(struct drm_bridge *bridge) { struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge); + const struct i2c_client *client = to_i2c_client(pdata->dev); + int ret; /* * Device needs to be powered on before reading the HPD state @@ -1219,11 +1261,35 @@ static void ti_sn_bridge_hpd_enable(struct drm_bridge *bridge) */ pm_runtime_get_sync(pdata->dev); + + mutex_lock(&pdata->hpd_mutex); + pdata->hpd_enabled = true; + mutex_unlock(&pdata->hpd_mutex); + + if (client->irq) { + ret = regmap_set_bits(pdata->regmap, SN_IRQ_EVENTS_EN_REG, + HPD_REMOVAL_EN | HPD_INSERTION_EN); + if (ret) + dev_err(pdata->dev, "Failed to enable HPD events: %d\n", ret); + } } static void ti_sn_bridge_hpd_disable(struct drm_bridge *bridge) { struct ti_sn65dsi86 *pdata = bridge_to_ti_sn65dsi86(bridge); + const struct i2c_client *client = to_i2c_client(pdata->dev); + int ret; + + if (client->irq) { + ret = regmap_clear_bits(pdata->regmap, SN_IRQ_EVENTS_EN_REG, + HPD_REMOVAL_EN | HPD_INSERTION_EN); + if (ret) + dev_err(pdata->dev, "Failed to disable HPD events: %d\n", ret); + } + + mutex_lock(&pdata->hpd_mutex); + pdata->hpd_enabled = false; + mutex_unlock(&pdata->hpd_mutex); pm_runtime_put_autosuspend(pdata->dev); } @@ -1309,6 +1375,41 @@ static int ti_sn_bridge_parse_dsi_host(struct ti_sn65dsi86 *pdata) return 0; } +static irqreturn_t ti_sn_bridge_interrupt(int irq, void *private) +{ + struct ti_sn65dsi86 *pdata = private; + struct drm_device *dev = pdata->bridge.dev; + u8 status; + int ret; + bool hpd_event; + + ret = ti_sn65dsi86_read_u8(pdata, SN_IRQ_STATUS_REG, &status); + if (ret) { + dev_err(pdata->dev, "Failed to read IRQ status: %d\n", ret); + return IRQ_NONE; + } + + hpd_event = status & (HPD_REMOVAL_STATUS | HPD_INSERTION_STATUS); + + dev_dbg(pdata->dev, "(SN_IRQ_STATUS_REG = %#x)\n", status); + if (!status) + return IRQ_NONE; + + ret = regmap_write(pdata->regmap, SN_IRQ_STATUS_REG, status); + if (ret) { + dev_err(pdata->dev, "Failed to clear IRQ status: %d\n", ret); + return IRQ_NONE; + } + + /* Only send the HPD event if we are bound with a device. */ + mutex_lock(&pdata->hpd_mutex); + if (pdata->hpd_enabled && hpd_event) + drm_kms_helper_hotplug_event(dev); + mutex_unlock(&pdata->hpd_mutex); + + return IRQ_HANDLED; +} + static int ti_sn_bridge_probe(struct auxiliary_device *adev, const struct auxiliary_device_id *id) { @@ -1933,6 +2034,7 @@ static int ti_sn65dsi86_probe(struct i2c_client *client) dev_set_drvdata(dev, pdata); pdata->dev = dev; + mutex_init(&pdata->hpd_mutex); mutex_init(&pdata->comms_mutex); pdata->regmap = devm_regmap_init_i2c(client, @@ -1973,6 +2075,16 @@ static int ti_sn65dsi86_probe(struct i2c_client *client) if (strncmp(id_buf, "68ISD ", ARRAY_SIZE(id_buf))) return dev_err_probe(dev, -EOPNOTSUPP, "unsupported device id\n"); + if (client->irq) { + ret = devm_request_threaded_irq(pdata->dev, client->irq, NULL, + ti_sn_bridge_interrupt, + IRQF_ONESHOT, + dev_name(pdata->dev), pdata); + + if (ret) + return dev_err_probe(dev, ret, "failed to request interrupt\n"); + } + /* * Break ourselves up into a collection of aux devices. The only real * motiviation here is to solve the chicken-and-egg problem of probe -- cgit v1.2.3