reset: socfpga: add reset driver for SoCFPGA platform

Add a DM compatible reset driver for the SoCFPGA platform.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

drivers/reset/Kconfig

@@ -91,4 +91,11 @@ config RESET_MESON
 	help
 	  Support for reset controller on Amlogic Meson SoC.
 
+config RESET_SOCFPGA
+	bool "Reset controller driver for SoCFPGA"
+	depends on DM_RESET && ARCH_SOCFPGA
+	default y
+	help
+	  Support for reset controller on SoCFPGA platform.
+
 endmenu

drivers/reset/Makefile

@@ -14,3 +14,4 @@ obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
 obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
 obj-$(CONFIG_RESET_MESON) += reset-meson.o
+obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o

drivers/reset/reset-socfpga.c

@@ -0,0 +1,105 @@
+/*
+ * Socfpga Reset Controller Driver
+ *
+ * Copyright 2014 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ *
+ * based on
+ * Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/of_access.h>
+#include <reset-uclass.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/sizes.h>
+
+#define BANK_INCREMENT		4
+#define NR_BANKS		8
+
+struct socfpga_reset_data {
+	void __iomem *membase;
+};
+
+static int socfpga_reset_assert(struct reset_ctl *reset_ctl)
+{
+	struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
+	int id = reset_ctl->id;
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+
+	setbits_le32(data->membase + (bank * BANK_INCREMENT), BIT(offset));
+	return 0;
+}
+
+static int socfpga_reset_deassert(struct reset_ctl *reset_ctl)
+{
+	struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
+	int id = reset_ctl->id;
+	int reg_width = sizeof(u32);
+	int bank = id / (reg_width * BITS_PER_BYTE);
+	int offset = id % (reg_width * BITS_PER_BYTE);
+
+	clrbits_le32(data->membase + (bank * BANK_INCREMENT), BIT(offset));
+	return 0;
+}
+
+static int socfpga_reset_request(struct reset_ctl *reset_ctl)
+{
+	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__,
+	      reset_ctl, reset_ctl->dev, reset_ctl->id);
+
+	return 0;
+}
+
+static int socfpga_reset_free(struct reset_ctl *reset_ctl)
+{
+	debug("%s(reset_ctl=%p) (dev=%p, id=%lu)\n", __func__, reset_ctl,
+	      reset_ctl->dev, reset_ctl->id);
+
+	return 0;
+}
+
+static const struct reset_ops socfpga_reset_ops = {
+	.request = socfpga_reset_request,
+	.free = socfpga_reset_free,
+	.rst_assert = socfpga_reset_assert,
+	.rst_deassert = socfpga_reset_deassert,
+};
+
+static int socfpga_reset_probe(struct udevice *dev)
+{
+	struct socfpga_reset_data *data = dev_get_priv(dev);
+	const void *blob = gd->fdt_blob;
+	int node = dev_of_offset(dev);
+	u32 modrst_offset;
+
+	data->membase = devfdt_get_addr_ptr(dev);
+
+	modrst_offset = fdtdec_get_int(blob, node, "altr,modrst-offset", 0x10);
+	data->membase += modrst_offset;
+
+	return 0;
+}
+
+static const struct udevice_id socfpga_reset_match[] = {
+	{ .compatible = "altr,rst-mgr" },
+	{ /* sentinel */ },
+};
+
+U_BOOT_DRIVER(socfpga_reset) = {
+	.name = "socfpga-reset",
+	.id = UCLASS_RESET,
+	.of_match = socfpga_reset_match,
+	.probe = socfpga_reset_probe,
+	.priv_auto_alloc_size = sizeof(struct socfpga_reset_data),
+	.ops = &socfpga_reset_ops,
+};