1 files changed, 132 insertions, 0 deletions
diff --git a/drivers/power/reset/qnap-poweroff.c b/drivers/power/reset/qnap-poweroff.c
new file mode 100644
index 000000000..0ddf7f25f
--- /dev/null
+++ b/drivers/power/reset/qnap-poweroff.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * QNAP Turbo NAS Board power off. Can also be used on Synology devices.
+ *
+ * Copyright (C) 2012 Andrew Lunn <andrew@lunn.ch>
+ *
+ * Based on the code from:
+ *
+ * Copyright (C) 2009  Martin Michlmayr <tbm@cyrius.com>
+ * Copyright (C) 2008  Byron Bradley <byron.bbradley@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/serial_reg.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+
+#define UART1_REG(x)	(base + ((UART_##x) << 2))
+
+struct power_off_cfg {
+	u32 baud;
+	char cmd;
+};
+
+static const struct power_off_cfg qnap_power_off_cfg = {
+	.baud = 19200,
+	.cmd = 'A',
+};
+
+static const struct power_off_cfg synology_power_off_cfg = {
+	.baud = 9600,
+	.cmd = '1',
+};
+
+static const struct of_device_id qnap_power_off_of_match_table[] = {
+	{ .compatible = "qnap,power-off",
+	  .data = &qnap_power_off_cfg,
+	},
+	{ .compatible = "synology,power-off",
+	  .data = &synology_power_off_cfg,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qnap_power_off_of_match_table);
+
+static void __iomem *base;
+static unsigned long tclk;
+static const struct power_off_cfg *cfg;
+
+static void qnap_power_off(void)
+{
+	const unsigned divisor = ((tclk + (8 * cfg->baud)) / (16 * cfg->baud));
+
+	pr_err("%s: triggering power-off...\n", __func__);
+
+	/* hijack UART1 and reset into sane state */
+	writel(0x83, UART1_REG(LCR));
+	writel(divisor & 0xff, UART1_REG(DLL));
+	writel((divisor >> 8) & 0xff, UART1_REG(DLM));
+	writel(0x03, UART1_REG(LCR));
+	writel(0x00, UART1_REG(IER));
+	writel(0x00, UART1_REG(FCR));
+	writel(0x00, UART1_REG(MCR));
+
+	/* send the power-off command to PIC */
+	writel(cfg->cmd, UART1_REG(TX));
+}
+
+static int qnap_power_off_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct resource *res;
+	struct clk *clk;
+
+	const struct of_device_id *match =
+		of_match_node(qnap_power_off_of_match_table, np);
+	cfg = match->data;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Missing resource");
+		return -EINVAL;
+	}
+
+	base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!base) {
+		dev_err(&pdev->dev, "Unable to map resource");
+		return -EINVAL;
+	}
+
+	/* We need to know tclk in order to calculate the UART divisor */
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "Clk missing");
+		return PTR_ERR(clk);
+	}
+
+	tclk = clk_get_rate(clk);
+
+	/* Check that nothing else has already setup a handler */
+	if (pm_power_off) {
+		dev_err(&pdev->dev, "pm_power_off already claimed for %ps",
+			pm_power_off);
+		return -EBUSY;
+	}
+	pm_power_off = qnap_power_off;
+
+	return 0;
+}
+
+static int qnap_power_off_remove(struct platform_device *pdev)
+{
+	pm_power_off = NULL;
+	return 0;
+}
+
+static struct platform_driver qnap_power_off_driver = {
+	.probe	= qnap_power_off_probe,
+	.remove	= qnap_power_off_remove,
+	.driver	= {
+		.name	= "qnap_power_off",
+		.of_match_table = of_match_ptr(qnap_power_off_of_match_table),
+	},
+};
+module_platform_driver(qnap_power_off_driver);
+
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
+MODULE_DESCRIPTION("QNAP Power off driver");
+MODULE_LICENSE("GPL v2");