The TI TPS380x family [1] is a volatage supervisor with a dedicated manual reset (mr) line input and a reset output. The chip(s) have a build in reset delay, depending on the chip partnumber. This simple driver addresses this so the cosumer don't need to care about it. [1] https://www.ti.com/product/TPS3801 Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx> --- drivers/reset/Kconfig | 8 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-tps380x.c | 130 ++++++++++++++++++++++++++++++++++ 3 files changed, 139 insertions(+) create mode 100644 drivers/reset/reset-tps380x.c diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index e0fc80e041ea..e2eb616af812 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -256,6 +256,14 @@ config RESET_TI_SYSCON you wish to use the reset framework for such memory-mapped devices, say Y here. Otherwise, say N. +config RESET_TI_TPS380X + tristate "TI TPS380x Reset Driver" + select GPIOLIB + help + This enables the reset driver support for TI TPS380x devices. If + you wish to use the reset framework for such devices, say Y here. + Otherwise, say N. + config RESET_TN48M_CPLD tristate "Delta Networks TN48M switch CPLD reset controller" depends on MFD_TN48M_CPLD || COMPILE_TEST diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index a80a9c4008a7..66399b92b1bb 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o +obj-$(CONFIG_RESET_TI_TPS380X) += reset-tps380x.o obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o diff --git a/drivers/reset/reset-tps380x.c b/drivers/reset/reset-tps380x.c new file mode 100644 index 000000000000..fd2c0929ae2d --- /dev/null +++ b/drivers/reset/reset-tps380x.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TI TPS380x Supply Voltage Supervisor and Reset Controller Driver + * + * Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@xxxxxxxxxxxxxx> + * + * Based on Simple Reset Controller Driver + * + * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@xxxxxxxxxxxxxx> + */ + +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/reset-controller.h> + +struct tps380x_reset { + struct reset_controller_dev rcdev; + struct gpio_desc *reset_gpio; + unsigned int reset_ms; +}; + +struct tps380x_reset_devdata { + unsigned int min_reset_ms; + unsigned int typ_reset_ms; + unsigned int max_reset_ms; +}; + +static inline +struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct tps380x_reset, rcdev); +} + +static int +tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id) +{ + struct tps380x_reset *tps380x = to_tps380x_reset(rcdev); + + gpiod_set_value_cansleep(tps380x->reset_gpio, 1); + + return 0; +} + +static int +tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id) +{ + struct tps380x_reset *tps380x = to_tps380x_reset(rcdev); + + gpiod_set_value_cansleep(tps380x->reset_gpio, 0); + msleep(tps380x->reset_ms); + + return 0; +} + +const struct reset_control_ops reset_tps380x_ops = { + .assert = tps380x_reset_assert, + .deassert = tps380x_reset_deassert, +}; + +static int tps380x_reset_of_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + /* No special handling needed, we have only one reset line per device */ + return 0; +} + +static int tps380x_reset_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct tps380x_reset_devdata *devdata; + struct tps380x_reset *tps380x; + + devdata = device_get_match_data(dev); + if (!devdata) + return -EINVAL; + + tps380x = devm_kzalloc(dev, sizeof(*tps380x), GFP_KERNEL); + if (!tps380x) + return -ENOMEM; + + tps380x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(tps380x->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(tps380x->reset_gpio), + "Failed to get GPIO\n"); + + /* + * Todo: + * Add firmware handling to switch between min/typ/max reset time + */ + tps380x->reset_ms = devdata->max_reset_ms; + + tps380x->rcdev.ops = &reset_tps380x_ops; + tps380x->rcdev.owner = THIS_MODULE; + tps380x->rcdev.dev = dev; + tps380x->rcdev.of_node = dev->of_node; + tps380x->rcdev.of_reset_n_cells = 0; + tps380x->rcdev.of_xlate = tps380x_reset_of_xlate; + tps380x->rcdev.nr_resets = 1; + + return devm_reset_controller_register(dev, &tps380x->rcdev); +} + +static const struct tps380x_reset_devdata tps3801_reset_data = { + .min_reset_ms = 120, + .typ_reset_ms = 200, + .max_reset_ms = 280, +}; + +static const struct of_device_id tps380x_reset_dt_ids[] = { + { .compatible = "ti,tps3801", .data = &tps3801_reset_data }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, tps380x_reset_dt_ids); + +static struct platform_driver tps380x_reset_driver = { + .probe = tps380x_reset_probe, + .driver = { + .name = "tps380x-reset", + .of_match_table = tps380x_reset_dt_ids, + }, +}; +module_platform_driver(tps380x_reset_driver); + +MODULE_AUTHOR("Marco Felsch <kernel@xxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("TI TPS380x Supply Voltags Supervisor and Reset Driver"); +MODULE_LICENSE("GPL v2"); -- 2.30.2
