Initial import

1 files changed, 108 insertions, 0 deletions

diff --git a/arch/arm/mach-prima2/rstc.c b/arch/arm/mach-prima2/rstc.c
new file mode 100644
index 000000000..7c251eb11
--- /dev/null
+++ b/arch/arm/mach-prima2/rstc.c
@@ -0,0 +1,108 @@
+/*
+ * reset controller for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/reset-controller.h>
+
+#include <asm/system_misc.h>
+
+#define SIRFSOC_RSTBIT_NUM	64
+
+static void __iomem *sirfsoc_rstc_base;
+static DEFINE_MUTEX(rstc_lock);
+
+static int sirfsoc_reset_module(struct reset_controller_dev *rcdev,
+					unsigned long sw_reset_idx)
+{
+	u32 reset_bit = sw_reset_idx;
+
+	if (reset_bit >= SIRFSOC_RSTBIT_NUM)
+		return -EINVAL;
+
+	mutex_lock(&rstc_lock);
+
+	/*
+	 * Writing 1 to this bit resets corresponding block.
+	 * Writing 0 to this bit de-asserts reset signal of the
+	 * corresponding block. datasheet doesn't require explicit
+	 * delay between the set and clear of reset bit. it could
+	 * be shorter if tests pass.
+	 */
+	writel(readl(sirfsoc_rstc_base +
+			(reset_bit / 32) * 4) | (1 << reset_bit),
+		sirfsoc_rstc_base + (reset_bit / 32) * 4);
+	msleep(20);
+	writel(readl(sirfsoc_rstc_base +
+			(reset_bit / 32) * 4) & ~(1 << reset_bit),
+		sirfsoc_rstc_base + (reset_bit / 32) * 4);
+
+	mutex_unlock(&rstc_lock);
+
+	return 0;
+}
+
+static struct reset_control_ops sirfsoc_rstc_ops = {
+	.reset = sirfsoc_reset_module,
+};
+
+static struct reset_controller_dev sirfsoc_reset_controller = {
+	.ops = &sirfsoc_rstc_ops,
+	.nr_resets = SIRFSOC_RSTBIT_NUM,
+};
+
+#define SIRFSOC_SYS_RST_BIT  BIT(31)
+
+static void sirfsoc_restart(enum reboot_mode mode, const char *cmd)
+{
+	writel(SIRFSOC_SYS_RST_BIT, sirfsoc_rstc_base);
+}
+
+static int sirfsoc_rstc_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	sirfsoc_rstc_base = of_iomap(np, 0);
+	if (!sirfsoc_rstc_base) {
+		dev_err(&pdev->dev, "unable to map rstc cpu registers\n");
+		return -ENOMEM;
+	}
+
+	sirfsoc_reset_controller.of_node = np;
+	arm_pm_restart = sirfsoc_restart;
+
+	if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
+		reset_controller_register(&sirfsoc_reset_controller);
+
+	return 0;
+}
+
+static const struct of_device_id rstc_ids[]  = {
+	{ .compatible = "sirf,prima2-rstc" },
+	{},
+};
+
+static struct platform_driver sirfsoc_rstc_driver = {
+	.probe		= sirfsoc_rstc_probe,
+	.driver		= {
+		.name	= "sirfsoc_rstc",
+		.of_match_table = rstc_ids,
+	},
+};
+
+static int __init sirfsoc_rstc_init(void)
+{
+	return platform_driver_register(&sirfsoc_rstc_driver);
+}
+subsys_initcall(sirfsoc_rstc_init);