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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | /* * QNAP Turbo NAS Board power off * * 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> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/serial_reg.h> #include <linux/kallsyms.h> #include <linux/of.h> #include <linux/io.h> #include <linux/clk.h> #define UART1_REG(x) (base + ((UART_##x) << 2)) static void __iomem *base; static unsigned long tclk; static void qnap_power_off(void) { /* 19200 baud divisor */ const unsigned divisor = ((tclk + (8 * 19200)) / (16 * 19200)); pr_err("%s: triggering power-off...\n", __func__); /* hijack UART1 and reset into sane state (19200,8n1) */ 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 'A' to PIC */ writel('A', UART1_REG(TX)); } static int qnap_power_off_probe(struct platform_device *pdev) { struct resource *res; struct clk *clk; char symname[KSYM_NAME_LEN]; 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) { lookup_symbol_name((ulong)pm_power_off, symname); dev_err(&pdev->dev, "pm_power_off already claimed %p %s", pm_power_off, symname); 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 const struct of_device_id qnap_power_off_of_match_table[] = { { .compatible = "qnap,power-off", }, {} }; MODULE_DEVICE_TABLE(of, qnap_power_off_of_match_table); static struct platform_driver qnap_power_off_driver = { .probe = qnap_power_off_probe, .remove = qnap_power_off_remove, .driver = { .owner = THIS_MODULE, .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"); |