From patchwork Tue Sep 17 08:53:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 829481 Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFCC8178397; Tue, 17 Sep 2024 08:53:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.193 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726563220; cv=none; b=lJ13sy7w9oZ4SbWwMmQ4qrRPhFSVpU/hhhAixL9e/xyJnDQPlpmH1Fu9Vs0BpgNIauI93zLETx90R/DUMy+msTGn6C1r5nimIQwlsI7xq3V4j3o55yOUZvEZykPBJoMTs0L+8sPiCpAVJx5t3tdwihwapVeIol+tDBRFGvwRT1k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726563220; c=relaxed/simple; bh=d46UyFg31sQdtl+sD0JkuMUtCzrEA2Rn4kzIuAmWtPk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ElGSkag3JFlgliSBxwW7qVCrHilQBGXf4jdcweywVE1hY7fKWrdcOh9ubTEYydPO65ujVHZUwHk0lvDOBdIShwZvMUr86sm3A0g+bp1b5ZW9sfvsIFBLhA6rNc4F/5DbWtsAMrUK2yFkjTF+gTDNAMrOIRQmg5o3ixYsYVPhsxE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=PBtMUpvs; arc=none smtp.client-ip=217.70.183.193 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="PBtMUpvs" Received: by mail.gandi.net (Postfix) with ESMTPSA id EC972240013; Tue, 17 Sep 2024 08:53:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1726563216; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HXAI/3ju1VCCwHCAXzm98BOlwNQZ+fS3qOU0jxqqHME=; b=PBtMUpvsQ6u8B6br9fNHriTcfs27bbqmsPcDiOOvE/K0+CWYRz7KkOmv96eLDMjFhye0BJ MCDjrTItCm0F/ZfRddlYvKkPyhQKl+4xrPd+REuiksVuV4kPnSjeBO4evplsR19lgrZ93x TCLy9AKbH6uRdSbIjbtG5p6y95P2awGt0h5p1EJ1q3qPCm2uFFxHGEOf7XqlU7SqD+YPTP ryjavBsToaMvdfQ12aiYGivWaPmNIFOB300pqtuW8GFCT0ST8IBlHs1nU/OyHraG1R05b/ Np1MCqZWxZlXqI2duqti4I5eJsScFndC6D9/zsfCIV8mpF9MC6NSw/+fE/V2Zg== From: Luca Ceresoli Date: Tue, 17 Sep 2024 10:53:12 +0200 Subject: [PATCH v4 8/8] misc: add ge-addon-connector driver Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240917-hotplug-drm-bridge-v4-8-bc4dfee61be6@bootlin.com> References: <20240917-hotplug-drm-bridge-v4-0-bc4dfee61be6@bootlin.com> In-Reply-To: <20240917-hotplug-drm-bridge-v4-0-bc4dfee61be6@bootlin.com> To: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Saravana Kannan , Wolfram Sang , "Rafael J. Wysocki" , Lee Jones , Daniel Thompson , Jingoo Han , Helge Deller Cc: Paul Kocialkowski , =?utf-8?q?Herv=C3=A9_Codina?= , Thomas Petazzoni , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-i2c@vger.kernel.org, linux-fbdev@vger.kernel.org, Paul Kocialkowski , Luca Ceresoli X-Mailer: b4 0.14.1 X-GND-Sasl: luca.ceresoli@bootlin.com Add a driver to support the runtime hot-pluggable add-on connector on the GE SUNH device. This connector allows connecting and disconnecting an add-on to/from the main device to augment its features. Connection and disconnection can happen at runtime at any moment without notice. Different add-on models can be connected, and each has an EEPROM with a model identifier at a fixed address. The add-on hardware is added and removed using device tree overlay loading and unloading. Co-developed-by: Herve Codina Signed-off-by: Herve Codina Signed-off-by: Luca Ceresoli --- Changed in v4: - rename 'nobus-devices' to 'devices' as per new bindings - remove the 'powergood' GPIO, removed from hardware design - rename "base" and "addon" overlays to "overlay 0" and "overlay 1" as the "addon" name is ambiguous - remove unused enum sunh_conn_overlay_level entries, then move the only remaining enum value to a define Changed in v3: - update to the new overlay representation that now does not include the target node; instead the target node is the connector node itself and is now passed by the connector driver to of_overlay_fdt_apply(), so the overlay is now decoupled from the base device tree - update to explicitely probe devices not reachable by the CPU on any physical bus (which probe as platform devices) which are now inside a 'nobus-devices' subnode of the connector node - change how the DRM bridge is populated to use the new device tree representation, having the video ports inside the 'dsi' node **NOTE** this specific change opens up a question about the .of_node_reused flag: setting it to true might be wrong now as the bridge will be handed the 'dsi' subnode of the connector node; however not setting it to true prevents the hotplug bridge module autoloading due to the alias string changing from "platform:hotplug-dsi-bridge" to "of:NdsiT(null)". - remove dev_info() and uninformative dev_dbg() calls - Kconfig: use 'depends on' instead of 'select' - Kconfig: improve help text and add module name This patch first appeared in v2. --- MAINTAINERS | 1 + drivers/misc/Kconfig | 18 ++ drivers/misc/Makefile | 1 + drivers/misc/ge-sunh-connector.c | 481 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 501 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 95a05eb75202..7dec59888df2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10278,6 +10278,7 @@ F: drivers/iio/pressure/mprls0025pa* HOTPLUG CONNECTOR FOR GE SUNH ADDONS M: Luca Ceresoli S: Maintained +F: drivers/misc/ge-sunh-connector.c F: Documentation/devicetree/bindings/connector/ge,sunh-addon-connector.yaml HP BIOSCFG DRIVER diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 41c54051347a..e2a5bcce0073 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -600,6 +600,24 @@ config MARVELL_CN10K_DPI To compile this driver as a module, choose M here: the module will be called mrvl_cn10k_dpi. +config GE_SUNH_CONNECTOR + tristate "GE SUNH hotplug add-on connector" + depends on OF_OVERLAY + depends on NVMEM + depends on DRM_HOTPLUG_BRIDGE + select FW_LOADER + help + Driver for the runtime hot-pluggable add-on connector on the GE + SUNH device. This connector allows connecting an add-on to the + main device to augment its features, and to later disconnect + it. Connection and disconnection can be done at runtime at any + moment without notice. Different add-on models can be connected, + and each has an EEPROM with a model identifier at a fixed + address. + + To compile this driver as a module, choose M here. + The module will be called ge-sunh-connector. + source "drivers/misc/c2port/Kconfig" source "drivers/misc/eeprom/Kconfig" source "drivers/misc/cb710/Kconfig" diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index c2f990862d2b..69747b048046 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -70,4 +70,5 @@ obj-$(CONFIG_TPS6594_ESM) += tps6594-esm.o obj-$(CONFIG_TPS6594_PFSM) += tps6594-pfsm.o obj-$(CONFIG_NSM) += nsm.o obj-$(CONFIG_MARVELL_CN10K_DPI) += mrvl_cn10k_dpi.o +obj-$(CONFIG_GE_SUNH_CONNECTOR) += ge-sunh-connector.o obj-y += keba/ diff --git a/drivers/misc/ge-sunh-connector.c b/drivers/misc/ge-sunh-connector.c new file mode 100644 index 000000000000..0e6064a9a519 --- /dev/null +++ b/drivers/misc/ge-sunh-connector.c @@ -0,0 +1,481 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GE SUNH hotplug add-on connector + * + * Driver for the runtime hot-pluggable add-on connector on the GE SUNH + * device. Add-on connection is detected via GPIOs (+ a debugfs + * trigger). On connection, a "base" DT overlay is added that describes + * enough to reach the NVMEM cell with the model ID. Based on the ID, an + * add-on-specific overlay is loaded on top to describe everything else. + * + * Copyright (C) 2024, GE HealthCare + * + * Authors: + * Luca Ceresoli + * Herve Codina + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SUNH_CONN_OVERLAY_N_LEVELS 2 + +struct sunh_conn { + struct device *dev; + struct gpio_desc *reset_gpio; + struct gpio_desc *plugged_gpio; + + bool plugged; + int ovcs_id[SUNH_CONN_OVERLAY_N_LEVELS]; + struct mutex ovl_mutex; // serialize overlay code + struct notifier_block nvmem_nb; + struct work_struct nvmem_notifier_work; + + struct platform_device *hpb_pdev; + struct dentry *debugfs_root; +}; + +/* + * Populate all platform devices that are not on any bus. + * + * Populate devices without any I/O access from the CPU, (e.g. fixed + * regulators and gpio regulators). In the normal case of a device tree + * without runtime-loaded overlays these are direct children of the root + * node and as such they are populated as a special case. + * + * Within the hotplug connector they need to be at a deeper level of the + * tree. Moreover they are "segregated" in the "devices" node which allows + * to avoid trying of_platform_default_populate() on other kind of nodes. + * + * No need to depopulate them in this driver: of_platform_notify() will do + * that on overlay removal. + * + * In case a generalized framework for OF_based hotplug connector drivers + * will exist in the future, this function is definitely meant for the + * framework. + */ +static int sunh_conn_populate_nobus_devices(struct sunh_conn *conn) +{ + struct device_node *nobus_devs_dn; + int err; + + nobus_devs_dn = of_get_child_by_name(conn->dev->of_node, "devices"); + if (!nobus_devs_dn) + return 0; + + err = of_platform_default_populate(nobus_devs_dn, NULL, conn->dev); + if (err) + dev_err(conn->dev, "Failed to populate nobus devices\n"); + + of_node_put(nobus_devs_dn); + return err; +} + +static int sunh_conn_insert_overlay(struct sunh_conn *conn, + unsigned int level, + const char *filename) +{ + const struct firmware *fw; + int err; + + err = request_firmware(&fw, filename, conn->dev); + if (err) + return dev_err_probe(conn->dev, err, "Error requesting overlay %s", filename); + + dev_dbg(conn->dev, "insert overlay %d: %s", level, filename); + err = of_overlay_fdt_apply(fw->data, fw->size, &conn->ovcs_id[level], conn->dev->of_node); + if (err) + dev_err_probe(conn->dev, err, "Failed to apply overlay %s\n", filename); + else + err = sunh_conn_populate_nobus_devices(conn); + + if (err) { + int err2; + + /* changeset may be partially applied */ + err2 = of_overlay_remove(&conn->ovcs_id[level]); + if (err2 < 0) + dev_err_probe(conn->dev, err2, + "Failed to remove failed overlay %s\n", filename); + } + + release_firmware(fw); + + return err; +} + +/* Load the overlay common to all add-ons (enough to read the model ID) */ +static int sunh_conn_load_overlay_0(struct sunh_conn *conn) +{ + int err = 0; + + mutex_lock(&conn->ovl_mutex); + + if (conn->ovcs_id[0] != 0) { + dev_dbg(conn->dev, "base overlay already loaded\n"); + goto out_unlock; + } + + err = sunh_conn_insert_overlay(conn, 0, "imx8mp-sundv1-addon-base.dtbo"); + +out_unlock: + mutex_unlock(&conn->ovl_mutex); + return err; +} + +/* Load the model-specific overlay describing everything not in the overlay 0 */ +static int sunh_conn_load_overlay_1(struct sunh_conn *conn) +{ + u8 addon_id; + const char *filename; + int err; + + mutex_lock(&conn->ovl_mutex); + + if (conn->ovcs_id[0] == 0) { + dev_dbg(conn->dev, "base overlay not loaded\n"); + err = -EINVAL; + goto out_unlock; + } + + if (conn->ovcs_id[1] != 0) { + dev_dbg(conn->dev, "addon overlay already loaded\n"); + err = -EEXIST; + goto out_unlock; + } + + err = nvmem_cell_read_u8(conn->dev, "id", &addon_id); + if (err) + goto out_unlock; + + dev_dbg(conn->dev, "Found add-on ID %d\n", addon_id); + + switch (addon_id) { + case 23: + filename = "imx8mp-sundv1-addon-13.dtbo"; + break; + case 24: + filename = "imx8mp-sundv1-addon-15.dtbo"; + break; + case 25: + filename = "imx8mp-sundv1-addon-18.dtbo"; + break; + default: + dev_warn(conn->dev, "Unknown add-on ID %d\n", addon_id); + err = -ENODEV; + goto out_unlock; + } + + err = sunh_conn_insert_overlay(conn, 1, filename); + +out_unlock: + mutex_unlock(&conn->ovl_mutex); + return err; +} + +static void sunh_conn_unload_overlays(struct sunh_conn *conn) +{ + int level = SUNH_CONN_OVERLAY_N_LEVELS; + int err; + + mutex_lock(&conn->ovl_mutex); + while (level) { + level--; + + if (conn->ovcs_id[level] == 0) + continue; + + dev_dbg(conn->dev, "remove overlay %d (ovcs id %d)", + level, conn->ovcs_id[level]); + + err = of_overlay_remove(&conn->ovcs_id[level]); + if (err) + dev_err_probe(conn->dev, err, "Failed to remove overlay %d\n", level); + } + mutex_unlock(&conn->ovl_mutex); +} + +static void sunh_conn_reset(struct sunh_conn *conn, bool keep_reset) +{ + gpiod_set_value_cansleep(conn->reset_gpio, 1); + + if (keep_reset) + return; + + mdelay(10); + gpiod_set_value_cansleep(conn->reset_gpio, 0); + mdelay(10); +} + +static int sunh_conn_detach(struct sunh_conn *conn) +{ + /* Cancel any pending NVMEM notification jobs */ + cancel_work_sync(&conn->nvmem_notifier_work); + + /* Unload previouly loaded overlays */ + sunh_conn_unload_overlays(conn); + + /* Set reset signal to have it set on next plug */ + sunh_conn_reset(conn, true); + + return 0; +} + +static int sunh_conn_attach(struct sunh_conn *conn) +{ + int err; + + /* Reset the plugged board in order to start from a stable state */ + sunh_conn_reset(conn, false); + + err = sunh_conn_load_overlay_0(conn); + if (err) + goto err; + + /* + * -EPROBE_DEFER can be due to NVMEM cell not yet available, so + * don't give up, an NVMEM event could arrive later + */ + err = sunh_conn_load_overlay_1(conn); + if (err && err != -EPROBE_DEFER) + goto err; + + return 0; + +err: + sunh_conn_detach(conn); + return err; +} + +static int sunh_conn_handle_event(struct sunh_conn *conn, bool plugged) +{ + int err; + + if (plugged == conn->plugged) + return 0; + + dev_dbg(conn->dev, "%s\n", plugged ? "connected" : "disconnected"); + + err = (plugged ? + sunh_conn_attach(conn) : + sunh_conn_detach(conn)); + + conn->plugged = plugged; + + return err; +} + +/* + * Return the current status of the connector as reported by the hardware, + * logging any errors. + */ +static int sunh_conn_get_connector_status(struct sunh_conn *conn) +{ + int val = gpiod_get_value_cansleep(conn->plugged_gpio); + + if (val < 0) + dev_err(conn->dev, "Error reading plugged GPIO (%d)\n", val); + + return val; +} + +static irqreturn_t sunh_conn_gpio_irq(int irq, void *data) +{ + struct sunh_conn *conn = data; + int conn_status; + + conn_status = sunh_conn_get_connector_status(conn); + if (conn_status >= 0) + sunh_conn_handle_event(conn, conn_status); + + return IRQ_HANDLED; +} + +static int plugged_read(void *dat, u64 *val) +{ + struct sunh_conn *conn = dat; + + *val = conn->plugged; + + return 0; +} + +static int plugged_write(void *dat, u64 val) +{ + struct sunh_conn *conn = dat; + + if (val > 1) + return -EINVAL; + + return sunh_conn_handle_event(conn, val); +} + +DEFINE_DEBUGFS_ATTRIBUTE(plugged_fops, plugged_read, plugged_write, "%lld\n"); + +static void sunh_conn_nvmem_notifier_work(struct work_struct *work) +{ + struct sunh_conn *conn = container_of(work, struct sunh_conn, nvmem_notifier_work); + + sunh_conn_load_overlay_1(conn); +} + +static int sunh_conn_nvmem_notifier(struct notifier_block *nb, unsigned long action, void *arg) +{ + struct sunh_conn *conn = container_of(nb, struct sunh_conn, nvmem_nb); + + if (action == NVMEM_CELL_ADD) + queue_work(system_power_efficient_wq, &conn->nvmem_notifier_work); + + return NOTIFY_OK; +} + +static int sunh_conn_register_drm_bridge(struct sunh_conn *conn) +{ + struct device *dev = conn->dev; + struct device_node *dsi_np; + + dsi_np = of_get_child_by_name(dev->of_node, "dsi"); + if (!dsi_np) + return dev_err_probe(dev, -ENOENT, "dsi node not found"); + + const struct platform_device_info hpb_info = { + .parent = dev, + .fwnode = of_fwnode_handle(dsi_np), + .of_node_reused = true, + .name = "hotplug-dsi-bridge", + .id = PLATFORM_DEVID_NONE, + }; + + conn->hpb_pdev = platform_device_register_full(&hpb_info); + of_node_put(dsi_np); // platform core gets/puts the device node + if (IS_ERR(conn->hpb_pdev)) + return dev_err_probe(dev, PTR_ERR(conn->hpb_pdev), + "Error registering DRM bridge\n"); + + return 0; +} + +static void sunh_conn_unregister_drm_bridge(struct sunh_conn *conn) +{ + platform_device_unregister(conn->hpb_pdev); +} + +static int sunh_conn_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct sunh_conn *conn; + int conn_status; + int err; + + /* Cannot load overlay from filesystem before rootfs is mounted */ + if (system_state < SYSTEM_RUNNING) + return -EPROBE_DEFER; + + conn = devm_kzalloc(dev, sizeof(*conn), GFP_KERNEL); + if (!conn) + return -ENOMEM; + + platform_set_drvdata(pdev, conn); + conn->dev = dev; + + mutex_init(&conn->ovl_mutex); + INIT_WORK(&conn->nvmem_notifier_work, sunh_conn_nvmem_notifier_work); + + conn->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(conn->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(conn->reset_gpio), + "Error getting reset GPIO\n"); + + conn->plugged_gpio = devm_gpiod_get_optional(dev, "plugged", GPIOD_IN); + if (IS_ERR(conn->plugged_gpio)) + return dev_err_probe(dev, PTR_ERR(conn->plugged_gpio), + "Error getting plugged GPIO\n"); + + err = sunh_conn_register_drm_bridge(conn); + if (err) + return err; + + conn->nvmem_nb.notifier_call = sunh_conn_nvmem_notifier; + err = nvmem_register_notifier(&conn->nvmem_nb); + if (err) { + dev_err_probe(dev, err, "Error registering NVMEM notifier\n"); + goto err_unregister_drm_bridge; + } + + if (conn->plugged_gpio) { + err = devm_request_threaded_irq(dev, gpiod_to_irq(conn->plugged_gpio), + NULL, sunh_conn_gpio_irq, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | + IRQF_ONESHOT, + dev_name(dev), conn); + if (err) { + dev_err_probe(dev, err, "Error getting plugged GPIO IRQ\n"); + goto err_nvmem_unregister_notifier; + } + } + + conn_status = sunh_conn_get_connector_status(conn); + if (conn_status < 0) { + err = conn_status; + goto err_nvmem_unregister_notifier; + } + + /* Ensure initial state is known and overlay loaded if plugged */ + sunh_conn_handle_event(conn, conn_status); + + conn->debugfs_root = debugfs_create_dir(dev_name(dev), NULL); + debugfs_create_file("plugged", 0644, conn->debugfs_root, conn, &plugged_fops); + + return 0; + +err_nvmem_unregister_notifier: + nvmem_unregister_notifier(&conn->nvmem_nb); + cancel_work_sync(&conn->nvmem_notifier_work); +err_unregister_drm_bridge: + sunh_conn_unregister_drm_bridge(conn); + return err; +} + +static void sunh_conn_remove(struct platform_device *pdev) +{ + struct sunh_conn *conn = platform_get_drvdata(pdev); + + debugfs_remove(conn->debugfs_root); + sunh_conn_detach(conn); + + nvmem_unregister_notifier(&conn->nvmem_nb); + cancel_work_sync(&conn->nvmem_notifier_work); + + sunh_conn_unregister_drm_bridge(conn); +} + +static const struct of_device_id sunh_conn_dt_ids[] = { + { .compatible = "ge,sunh-addon-connector" }, + {} +}; +MODULE_DEVICE_TABLE(of, sunh_conn_dt_ids); + +static struct platform_driver sunh_conn_driver = { + .driver = { + .name = "sunh-addon-connector", + .of_match_table = sunh_conn_dt_ids, + }, + .probe = sunh_conn_probe, + .remove_new = sunh_conn_remove, +}; +module_platform_driver(sunh_conn_driver); + +MODULE_AUTHOR("Luca Ceresoli "); +MODULE_AUTHOR("Herve Codina "); +MODULE_DESCRIPTION("GE SUNH hotplug add-on connector"); +MODULE_LICENSE("GPL");