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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 | // 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/kallsyms.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; char symname[KSYM_NAME_LEN]; 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) { 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 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"); |