From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 175A52FD1A9; Thu, 14 Aug 2025 10:52:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755168734; cv=none; b=EJo4SxHuRBUl+/I3tGKeaLUX966x2EnRfK3uYE83VTrwBOP2dOEgzgo+q7FAtjQLaitLM5/PglLqWBVtHuvOA7xq7RYYyoQLMn/QjD9ZbqToOpTckAoC8Jnah1JlSufK747djSAZv5bbrof+FkUofEm5AwUTNyphMOzE2HE92/0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755168734; c=relaxed/simple; bh=cCEgYLnJf+5grhqhoUEvF8DCQ1F3ij1AI1rFPHd0Smw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IJZ/Msndjjga2YfGq6A2w6oEaC/Qjl0ZCFmTe7HEQVkPi7Fh0IHY8g20K3W8M/3N+5i+SZGmN4MLYHCynjxxmjUz2Fnjji9LTz5H1oSfpsgDyntT3/QpTDZ4rDNS5bpuMUjhb5j5uPjUyaki3w3mxmvnbco/U0hJwghpkoqs6fg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YTuyRrM2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YTuyRrM2" Received: by smtp.kernel.org (Postfix) with ESMTPS id B1723C4CEEF; Thu, 14 Aug 2025 10:52:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755168733; bh=cCEgYLnJf+5grhqhoUEvF8DCQ1F3ij1AI1rFPHd0Smw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=YTuyRrM2AJbmp+987JBvu/I4lRFyBopz/rHTXPOcqz+j/02nE2Y4XGH/VKick5eV1 tyylKzd36Deg0waMzw5JbF2DgG+zTjtuwFclZDC/5ckAcUOjnkpZwsOrOv4QlCIr/U WWXTt6xj/Wy+ldcve3b/CxwKFyMuAtOY1ARq5ImPpDnPSMIOaDD5GpEwEyoLg56TqG Jia9ARGGM9RgzkWwigT7CSy0du2SRyzURsfqk/gXJYh4ODiP5kaEBTVK35ugLwyq6N 1/wC8PahfGLWuw3irOMKUqopE4RpL3Bw6X9K32xYICDF4glNIE1Ww3NOufB54g64mz Nw+H2UWRuwzMg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3AC8CA0EE6; Thu, 14 Aug 2025 10:52:13 +0000 (UTC) From: =?utf-8?q?Nuno_S=C3=A1_via_B4_Relay?= Date: Thu, 14 Aug 2025 11:52:24 +0100 Subject: [PATCH 2/6] mfd: ltc4283: Add support for the LTC4283 Swap Controller Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20250814-ltc4283-support-v1-2-88b2cef773f2@analog.com> References: <20250814-ltc4283-support-v1-0-88b2cef773f2@analog.com> In-Reply-To: <20250814-ltc4283-support-v1-0-88b2cef773f2@analog.com> To: linux-hwmon@vger.kernel.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Cc: Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jean Delvare , Guenter Roeck , Jonathan Corbet , Linus Walleij , Bartosz Golaszewski X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1755168752; l=7869; i=nuno.sa@analog.com; s=20231116; h=from:subject:message-id; bh=YJEiTHe9kb+DC8FT96u8vbrt9euhbvLgsuaavOLJvd0=; b=tNjM9wTGeiBzHFn7funqVFxJYEEVNZPoI1tUkvZkprAg+plh0sz0LBZQlK5MJ7vjcFs3+I0VC 6AbVLXGzHEbCL4PQXQ2qz3GfaV3ev+GdoXiqRvVB3MhlrL17E4cglFh X-Developer-Key: i=nuno.sa@analog.com; a=ed25519; pk=3NQwYA013OUYZsmDFBf8rmyyr5iQlxV/9H4/Df83o1E= X-Endpoint-Received: by B4 Relay for nuno.sa@analog.com/20231116 with auth_id=100 X-Original-From: =?utf-8?q?Nuno_S=C3=A1?= Reply-To: nuno.sa@analog.com From: Nuno Sá The LTC4283 is a negative voltage hot swap controller that drives an external N-channel MOSFET to allow a board to be safely inserted and removed from a live backplane. Main usage is as an Hardware Monitoring device. However, it has up to 8 pins that can be configured and used as GPIOs and hence, the device can also be a GPIO controller (and so being added as MFD device). Signed-off-by: Nuno Sá --- MAINTAINERS | 2 + drivers/mfd/Kconfig | 11 ++++ drivers/mfd/Makefile | 1 + drivers/mfd/ltc4283.c | 140 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/ltc4283.h | 33 +++++++++++ 5 files changed, 187 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 413bb77d5eebe2b51aa9c3af86e7cfd5ab142044..b5f4f1c41c64b738d57c1fb5552a60b4c6b9985c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14506,6 +14506,8 @@ L: linux-hwmon@vger.kernel.org L: linux-gpio@vger.kernel.org S: Supported F: Documentation/devicetree/bindings/mfd/adi,ltc4283.yaml +F: drivers/mfd/ltc4283.c +F: include/linux/mfd/ltc4283.h LTC4286 HARDWARE MONITOR DRIVER M: Delphine CC Chiu diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 425c5fba6cb1e7848dcea05bd77c729a71d48e2c..ec3e02d40fd17a0bba29e3157723055feedebd11 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -900,6 +900,17 @@ config MFD_MAX14577 additional drivers must be enabled in order to use the functionality of the device. +config MFD_LTC4283 + tristate "LTC4283 Hot Swap Controller" + depends on I2C + select MFD_CORE + select REGMAP_I2C + help + This enables support for the LTC4283 Negative Voltage Hot Swap + Controller. This driver provides common support for accessing the + device; additional drivers must be enabled in order to use the + functionality of the device. + config MFD_MAX77541 tristate "Analog Devices MAX77541/77540 PMIC Support" depends on I2C=y diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index f7bdedd5a66d16bf8ccee0da1236a441e6f085b0..4a3bcd30ab7e12aed4bc5e48294500c77cb61aa7 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_MFD_EXYNOS_LPASS) += exynos-lpass.o obj-$(CONFIG_MFD_GATEWORKS_GSC) += gateworks-gsc.o obj-$(CONFIG_MFD_MACSMC) += macsmc.o +obj-$(CONFIG_MFD_LTC4283) += ltc4283.o obj-$(CONFIG_MFD_TI_LP873X) += lp873x.o obj-$(CONFIG_MFD_TI_LP87565) += lp87565.o obj-$(CONFIG_MFD_TI_AM335X_TSCADC) += ti_am335x_tscadc.o diff --git a/drivers/mfd/ltc4283.c b/drivers/mfd/ltc4283.c new file mode 100644 index 0000000000000000000000000000000000000000..a45c01278f884630984790c922c057c4f2db9c82 --- /dev/null +++ b/drivers/mfd/ltc4283.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller + * + * Copyright 2025 Analog Devices Inc. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +static const struct mfd_cell ltc4283_cells[] = { + MFD_CELL_OF("ltc4283-hwmon", NULL, NULL, 0, 0, "adi,ltc4283-hwmon"), + MFD_CELL_OF("ltc4283-gpio", NULL, NULL, 0, 0, "adi,ltc4283-gpio"), +}; + +static bool ltc4283_writable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case 0x00 ... 0x03: + return false; + case 0x3c: + return false; + case 0x86 ... 0x8f: + return false; + case 0x91 ... 0xa1: + return false; + case 0xa3: + return false; + case 0xac: + return false; + case 0xf1 ... 0xff: + return false; + default: + return true; + } +} + +static const struct regmap_config ltc4283_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0xff, + .writeable_reg = ltc4283_writable_reg, +}; + +static int ltc4283_get_gpio_pins(struct i2c_client *client, u32 *n_cells) +{ + struct device *dev = &client->dev; + u32 pins[LTC4283_GPIO_MAX], pin; + unsigned long *gpio_mask; + int n_pins, ret; + + /* + * The device has up to 8 pins that can be configured either as GPIOS or + * for monitoring purposes. Both gpio and hwmon devices need to have + * this information in order to do proper validations and + * configurations. Hence, this property needs to be in the top level + * device. + */ + n_pins = device_property_count_u32(dev, "adi,gpio-pins"); + if (n_pins < 0) + return 0; + if (n_pins >= LTC4283_GPIO_MAX) + return dev_err_probe(dev, -EINVAL, "Too many GPIO pins specified (%d), max is %d\n", + n_pins, LTC4283_GPIO_MAX); + + ret = device_property_read_u32_array(dev, "adi,gpio-pins", pins, n_pins); + if (ret) + return dev_err_probe(dev, ret, "Failed to read GPIO pins\n"); + + gpio_mask = devm_bitmap_zalloc(dev, LTC4283_GPIO_MAX, GFP_KERNEL); + if (!gpio_mask) + return -ENOMEM; + + for (pin = 0; pin < n_pins; pin++) { + if (pins[pin] >= LTC4283_GPIO_MAX) + return dev_err_probe(dev, -EINVAL, + "Invalid GPIO pin specified (%u), max is %d\n", + pins[pin], LTC4283_GPIO_MAX); + + __set_bit(pins[pin], gpio_mask); + } + + /* Add the GPIO cell */ + *n_cells += 1; + i2c_set_clientdata(client, gpio_mask); + + return 0; +} + +static int ltc4283_probe(struct i2c_client *client) +{ + u32 n_cells = ARRAY_SIZE(ltc4283_cells) - 1; + struct regmap *regmap; + int ret; + + regmap = devm_regmap_init_i2c(client, <c4283_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + ret = ltc4283_get_gpio_pins(client, &n_cells); + if (ret) + return ret; + + return devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO, + ltc4283_cells, n_cells, NULL, 0, NULL); +} + +static const struct of_device_id ltc4283_of_match[] = { + { .compatible = "adi,ltc4283" }, + { } +}; +MODULE_DEVICE_TABLE(of, ltc4283_of_match); + +static const struct i2c_device_id ltc4283_i2c_id[] = { + { "ltc4283" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ltc4283_i2c_id); + +static struct i2c_driver ltc4283_driver = { + .driver = { + .name = "ltc4283", + .of_match_table = ltc4283_of_match, + }, + .probe = ltc4283_probe, + .id_table = ltc4283_i2c_id, +}; +module_i2c_driver(ltc4283_driver); + +MODULE_AUTHOR("Nuno Sá "); +MODULE_DESCRIPTION("LTC4283 MFD I2C driver"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/mfd/ltc4283.h b/include/linux/mfd/ltc4283.h new file mode 100644 index 0000000000000000000000000000000000000000..153594009c07b296ce5743e5e817e96464d81cb3 --- /dev/null +++ b/include/linux/mfd/ltc4283.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller + * + * Copyright 2025 Analog Devices Inc. + */ + +#ifndef __MFD_LTC4283_H_ +#define __MFD_LTC4283_H_ + +#include +#include + +/* + * We can have up to 8 gpios. 4 PGIOs and 4 ADIOs. PGIOs start at index 4 in the + * gpios mask. + */ +#define LTC4283_PGIOX_START_NR 4 + +#define LTC4283_PGIO_CONFIG 0x10 +#define LTC4283_PGIO_CFG_MASK(pin) \ + GENMASK(((pin) - LTC4283_PGIOX_START_NR) * 2 + 1, (((pin) - LTC4283_PGIOX_START_NR) * 2)) +#define LTC4283_PGIO_CONFIG_2 0x11 +#define LTC4283_ADC_MASK GENMASK(2, 0) +#define LTC4283_PGIO_OUT_MASK(pin) BIT(4 + (pin)) + +#define LTC4283_GPIO_MAX 8 + +/* Non-constant mask variant of FIELD_GET() and FIELD_PREP() */ +#define field_get(_mask, _reg) (((_reg) & (_mask)) >> (ffs(_mask) - 1)) +#define field_prep(_mask, _val) (((_val) << (ffs(_mask) - 1)) & (_mask)) + +#endif -- 2.50.1