@@ -27,6 +27,13 @@ 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_LPC18XX
bool "LPC18xx/43xx Reset Driver" if COMPILE_TEST
default ARCH_LPC18XX
@@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_STI) += sti/
obj-$(CONFIG_ARCH_TEGRA) += tegra/
obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_GEMINI) += reset-gemini.o
obj-$(CONFIG_RESET_LPC18XX) += reset-lpc18xx.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
new file mode 100644
@@ -0,0 +1,110 @@
+/*
+ * Cortina Gemini Reset controller driver
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * 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 <linux/err.h>
+#include <linux/init.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <dt-bindings/reset/cortina,gemini-reset.h>
+
+/**
+ * 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-reset", },
+ { /* 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);
The Cortina Systems Gemini reset controller is a simple 32bit register with self-deasserting reset lines. It is accessed using regmap over syscon. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - Add an explicit GPL license statement. - Move the reset controller to be identical to the sycon node, no need to a separate child node for this. - Drop unneeded struct device *dev pointer from state container. - Print error code on missing regmap. - Use #define from the <dt-bindings/*> to indicate that we always set the CPU1 reset line to 1 when writing the resets. --- 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