dm: reset: add BCM6345 reset driver

This is a simplified version of linux/arch/mips/bcm63xx/reset.c

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/reset/Kconfig

@@ -42,6 +42,12 @@ config TEGRA186_RESET
 	  Enable support for manipulating Tegra's on-SoC reset signals via IPC
 	  requests to the BPMP (Boot and Power Management Processor).
 
+config RESET_BCM6345
+	bool "Reset controller driver for BCM6345"
+	depends on DM_RESET && ARCH_BMIPS
+	help
+	  Support reset controller on BCM6345.
+
 config RESET_UNIPHIER
 	bool "Reset controller driver for UniPhier SoCs"
 	depends on ARCH_UNIPHIER

drivers/reset/Makefile

@@ -8,5 +8,6 @@ obj-$(CONFIG_SANDBOX_MBOX) += sandbox-reset-test.o
 obj-$(CONFIG_STI_RESET) += sti-reset.o
 obj-$(CONFIG_TEGRA_CAR_RESET) += tegra-car-reset.o
 obj-$(CONFIG_TEGRA186_RESET) += tegra186-reset.o
+obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o

drivers/reset/reset-bcm6345.c

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/arch/mips/bcm63xx/reset.c:
+ *	Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <reset-uclass.h>
+#include <asm/io.h>
+
+#define MAX_RESETS	32
+
+struct bcm6345_reset_priv {
+	void __iomem *regs;
+};
+
+static int bcm6345_reset_assert(struct reset_ctl *rst)
+{
+	struct bcm6345_reset_priv *priv = dev_get_priv(rst->dev);
+
+	clrbits_be32(priv->regs, BIT(rst->id));
+	mdelay(20);
+
+	return 0;
+}
+
+static int bcm6345_reset_deassert(struct reset_ctl *rst)
+{
+	struct bcm6345_reset_priv *priv = dev_get_priv(rst->dev);
+
+	setbits_be32(priv->regs, BIT(rst->id));
+	mdelay(20);
+
+	return 0;
+}
+
+static int bcm6345_reset_free(struct reset_ctl *rst)
+{
+	return 0;
+}
+
+static int bcm6345_reset_request(struct reset_ctl *rst)
+{
+	if (rst->id >= MAX_RESETS)
+		return -EINVAL;
+
+	return bcm6345_reset_assert(rst);
+}
+
+struct reset_ops bcm6345_reset_reset_ops = {
+	.free = bcm6345_reset_free,
+	.request = bcm6345_reset_request,
+	.rst_assert = bcm6345_reset_assert,
+	.rst_deassert = bcm6345_reset_deassert,
+};
+
+static const struct udevice_id bcm6345_reset_ids[] = {
+	{ .compatible = "brcm,bcm6345-reset" },
+	{ /* sentinel */ }
+};
+
+static int bcm6345_reset_probe(struct udevice *dev)
+{
+	struct bcm6345_reset_priv *priv = dev_get_priv(dev);
+	fdt_addr_t addr;
+	fdt_size_t size;
+
+	addr = dev_get_addr_size_index(dev, 0, &size);
+	if (addr == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	priv->regs = ioremap(addr, size);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(bcm6345_reset) = {
+	.name = "bcm6345-reset",
+	.id = UCLASS_RESET,
+	.of_match = bcm6345_reset_ids,
+	.ops = &bcm6345_reset_reset_ops,
+	.probe = bcm6345_reset_probe,
+	.priv_auto_alloc_size = sizeof(struct bcm6345_reset_priv),
+};