[U-Boot] [PATCH] reset: socfpga: add reset driver for SoCFPGA platform

[Dinh Nguyen]

Add a DM compatible reset driver for the SoCFPGA platform.

Signed-off-by: Dinh Nguyen <dinguyen at kernel.org>
---
 drivers/reset/Kconfig         |   7 +++
 drivers/reset/Makefile        |   1 +
 drivers/reset/reset-socfpga.c | 111 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 119 insertions(+)
 create mode 100644 drivers/reset/reset-socfpga.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 3964b9e..90b021f 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -83,4 +83,11 @@ config RESET_ROCKCHIP
 	  though is that some reset signals, like I2C or MISC reset multiple
 	  devices.
 
+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
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 7d7e080..6f791ee 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
 obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
+obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
new file mode 100644
index 0000000..af585ec
--- /dev/null
+++ b/drivers/reset/reset-socfpga.c
@@ -0,0 +1,111 @@
+/*
+ * Socfpga Reset Controller Driver
+ *
+ * Copyright 2014 Steffen Trumtrar <s.trumtrar at pengutronix.de>
+ *
+ * based on
+ * Allwinner SoCs Reset Controller driver
+ *
+ * Copyright 2013 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard at 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);
+	unsigned long flags;
+	u32 reg;
+
+	reg = readl(data->membase + (bank * BANK_INCREMENT));
+	writel(reg | BIT(offset), data->membase + (bank * BANK_INCREMENT));
+	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);
+	unsigned long flags;
+	u32 reg;
+
+	reg = readl(data->membase + (bank * BANK_INCREMENT));
+	writel(reg & ~BIT(offset), data->membase + (bank * BANK_INCREMENT));
+	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,
+};
-- 
2.7.4