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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 | /* * TI keystone reboot driver * * Copyright (C) 2014 Texas Instruments Incorporated. http://www.ti.com/ * * Author: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/io.h> #include <linux/module.h> #include <linux/notifier.h> #include <linux/reboot.h> #include <linux/regmap.h> #include <linux/mfd/syscon.h> #include <linux/of_platform.h> #define RSTYPE_RG 0x0 #define RSCTRL_RG 0x4 #define RSCFG_RG 0x8 #define RSISO_RG 0xc #define RSCTRL_KEY_MASK 0x0000ffff #define RSCTRL_RESET_MASK BIT(16) #define RSCTRL_KEY 0x5a69 #define RSMUX_OMODE_MASK 0xe #define RSMUX_OMODE_RESET_ON 0xa #define RSMUX_OMODE_RESET_OFF 0x0 #define RSMUX_LOCK_MASK 0x1 #define RSMUX_LOCK_SET 0x1 #define RSCFG_RSTYPE_SOFT 0x300f #define RSCFG_RSTYPE_HARD 0x0 #define WDT_MUX_NUMBER 0x4 static int rspll_offset; static struct regmap *pllctrl_regs; /** * rsctrl_enable_rspll_write - enable access to RSCTRL, RSCFG * To be able to access to RSCTRL, RSCFG registers * we have to write a key before */ static inline int rsctrl_enable_rspll_write(void) { return regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG, RSCTRL_KEY_MASK, RSCTRL_KEY); } static int rsctrl_restart_handler(struct notifier_block *this, unsigned long mode, void *cmd) { /* enable write access to RSTCTRL */ rsctrl_enable_rspll_write(); /* reset the SOC */ regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG, RSCTRL_RESET_MASK, 0); return NOTIFY_DONE; } static struct notifier_block rsctrl_restart_nb = { .notifier_call = rsctrl_restart_handler, .priority = 128, }; static const struct of_device_id rsctrl_of_match[] = { {.compatible = "ti,keystone-reset", }, {}, }; static int rsctrl_probe(struct platform_device *pdev) { int i; int ret; u32 val; unsigned int rg; u32 rsmux_offset; struct regmap *devctrl_regs; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; if (!np) return -ENODEV; /* get regmaps */ pllctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-pll"); if (IS_ERR(pllctrl_regs)) return PTR_ERR(pllctrl_regs); devctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev"); if (IS_ERR(devctrl_regs)) return PTR_ERR(devctrl_regs); ret = of_property_read_u32_index(np, "ti,syscon-pll", 1, &rspll_offset); if (ret) { dev_err(dev, "couldn't read the reset pll offset!\n"); return -EINVAL; } ret = of_property_read_u32_index(np, "ti,syscon-dev", 1, &rsmux_offset); if (ret) { dev_err(dev, "couldn't read the rsmux offset!\n"); return -EINVAL; } /* set soft/hard reset */ val = of_property_read_bool(np, "ti,soft-reset"); val = val ? RSCFG_RSTYPE_SOFT : RSCFG_RSTYPE_HARD; ret = rsctrl_enable_rspll_write(); if (ret) return ret; ret = regmap_write(pllctrl_regs, rspll_offset + RSCFG_RG, val); if (ret) return ret; /* disable a reset isolation for all module clocks */ ret = regmap_write(pllctrl_regs, rspll_offset + RSISO_RG, 0); if (ret) return ret; /* enable a reset for watchdogs from wdt-list */ for (i = 0; i < WDT_MUX_NUMBER; i++) { ret = of_property_read_u32_index(np, "ti,wdt-list", i, &val); if (ret == -EOVERFLOW && !i) { dev_err(dev, "ti,wdt-list property has to contain at" "least one entry\n"); return -EINVAL; } else if (ret) { break; } if (val >= WDT_MUX_NUMBER) { dev_err(dev, "ti,wdt-list property can contain" "only numbers < 4\n"); return -EINVAL; } rg = rsmux_offset + val * 4; ret = regmap_update_bits(devctrl_regs, rg, RSMUX_OMODE_MASK, RSMUX_OMODE_RESET_ON | RSMUX_LOCK_SET); if (ret) return ret; } ret = register_restart_handler(&rsctrl_restart_nb); if (ret) dev_err(dev, "cannot register restart handler (err=%d)\n", ret); return ret; } static struct platform_driver rsctrl_driver = { .probe = rsctrl_probe, .driver = { .name = KBUILD_MODNAME, .of_match_table = rsctrl_of_match, }, }; module_platform_driver(rsctrl_driver); MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>"); MODULE_DESCRIPTION("Texas Instruments keystone reset driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:" KBUILD_MODNAME); |