From 2acb037fc42b8ce5ae59a7d5db3c9b35672e3dd7 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 24 May 2017 10:19:20 +0200 Subject: reset: Add a Gemini reset controller The Cortina Systems Gemini reset controller is a simple 32bit register with self-deasserting reset lines. It is accessed using regmap over syscon. Acked-by: Philipp Zabel Signed-off-by: Linus Walleij Signed-off-by: Philipp Zabel --- drivers/reset/Kconfig | 7 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-gemini.c | 110 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 118 insertions(+) create mode 100644 drivers/reset/reset-gemini.c (limited to 'drivers/reset') diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 42d5631c6da0..61fabf6ddaec 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -34,6 +34,13 @@ config RESET_BERLIN help This enables the reset controller driver for Marvell Berlin SoCs. +config RESET_GEMINI + bool "Gemini Reset Driver" if COMPILE_TEST + default ARCH_GEMINI + select MFD_SYSCON + help + This enables the reset controller driver for Cortina Systems Gemini. + config RESET_IMX7 bool "i.MX7 Reset Driver" if COMPILE_TEST default SOC_IMX7D diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 26270e0f8342..e422a04f7b85 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -5,6 +5,7 @@ obj-$(CONFIG_ARCH_TEGRA) += tegra/ obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o obj-$(CONFIG_RESET_ATH79) += reset-ath79.o obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o +obj-$(CONFIG_RESET_GEMINI) += reset-gemini.o obj-$(CONFIG_RESET_IMX7) += reset-imx7.o obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o obj-$(CONFIG_RESET_MESON) += reset-meson.o diff --git a/drivers/reset/reset-gemini.c b/drivers/reset/reset-gemini.c new file mode 100644 index 000000000000..a2478997c75b --- /dev/null +++ b/drivers/reset/reset-gemini.c @@ -0,0 +1,110 @@ +/* + * Cortina Gemini Reset controller driver + * Copyright (C) 2017 Linus Walleij + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * struct gemini_reset - gemini reset controller + * @map: regmap to access the containing system controller + * @rcdev: reset controller device + */ +struct gemini_reset { + struct regmap *map; + struct reset_controller_dev rcdev; +}; + +#define GEMINI_GLOBAL_SOFT_RESET 0x0c + +#define to_gemini_reset(p) \ + container_of((p), struct gemini_reset, rcdev) + +/* + * This is a self-deasserting reset controller. + */ +static int gemini_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct gemini_reset *gr = to_gemini_reset(rcdev); + + /* Manual says to always set BIT 30 (CPU1) to 1 */ + return regmap_write(gr->map, + GEMINI_GLOBAL_SOFT_RESET, + BIT(GEMINI_RESET_CPU1) | BIT(id)); +} + +static int gemini_reset_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct gemini_reset *gr = to_gemini_reset(rcdev); + u32 val; + int ret; + + ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val); + if (ret) + return ret; + + return !!(val & BIT(id)); +} + +static const struct reset_control_ops gemini_reset_ops = { + .reset = gemini_reset, + .status = gemini_reset_status, +}; + +static int gemini_reset_probe(struct platform_device *pdev) +{ + struct gemini_reset *gr; + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + int ret; + + gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL); + if (!gr) + return -ENOMEM; + + gr->map = syscon_node_to_regmap(np); + if (IS_ERR(gr->map)) { + ret = PTR_ERR(gr->map); + dev_err(dev, "unable to get regmap (%d)", ret); + return ret; + } + gr->rcdev.owner = THIS_MODULE; + gr->rcdev.nr_resets = 32; + gr->rcdev.ops = &gemini_reset_ops; + gr->rcdev.of_node = pdev->dev.of_node; + + ret = devm_reset_controller_register(&pdev->dev, &gr->rcdev); + if (ret) + return ret; + + dev_info(dev, "registered Gemini reset controller\n"); + return 0; +} + +static const struct of_device_id gemini_reset_dt_ids[] = { + { .compatible = "cortina,gemini-syscon", }, + { /* sentinel */ }, +}; + +static struct platform_driver gemini_reset_driver = { + .probe = gemini_reset_probe, + .driver = { + .name = "gemini-reset", + .of_match_table = gemini_reset_dt_ids, + .suppress_bind_attrs = true, + }, +}; +builtin_platform_driver(gemini_reset_driver); -- cgit v1.2.3