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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 | /* * Atmel AT91 SAM9 SoCs reset code * * Copyright (C) 2007 Atmel Corporation. * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> * Copyright (C) 2014 Free Electrons * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/clk.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/printk.h> #include <soc/at91/at91sam9_ddrsdr.h> #define AT91_SHDW_CR 0x00 /* Shut Down Control Register */ #define AT91_SHDW_SHDW BIT(0) /* Shut Down command */ #define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */ #define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */ #define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */ #define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */ #define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */ #define AT91_SHDW_CPTWK0_(x) ((x) << 4) #define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */ #define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */ #define AT91_SHDW_SR 0x08 /* Shut Down Status Register */ #define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */ #define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */ #define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */ enum wakeup_type { AT91_SHDW_WKMODE0_NONE = 0, AT91_SHDW_WKMODE0_HIGH = 1, AT91_SHDW_WKMODE0_LOW = 2, AT91_SHDW_WKMODE0_ANYLEVEL = 3, }; static const char *shdwc_wakeup_modes[] = { [AT91_SHDW_WKMODE0_NONE] = "none", [AT91_SHDW_WKMODE0_HIGH] = "high", [AT91_SHDW_WKMODE0_LOW] = "low", [AT91_SHDW_WKMODE0_ANYLEVEL] = "any", }; static struct shdwc { struct clk *sclk; void __iomem *shdwc_base; void __iomem *mpddrc_base; } at91_shdwc; static void at91_wakeup_status(struct platform_device *pdev) { const char *reason; u32 reg = readl(at91_shdwc.shdwc_base + AT91_SHDW_SR); /* Simple power-on, just bail out */ if (!reg) return; if (reg & AT91_SHDW_RTTWK) reason = "RTT"; else if (reg & AT91_SHDW_RTCWK) reason = "RTC"; else reason = "unknown"; dev_info(&pdev->dev, "Wake-Up source: %s\n", reason); } static void at91_poweroff(void) { asm volatile( /* Align to cache lines */ ".balign 32\n\t" /* Ensure AT91_SHDW_CR is in the TLB by reading it */ " ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" /* Power down SDRAM0 */ " tst %0, #0\n\t" " beq 1f\n\t" " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" /* Shutdown CPU */ "1: str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" " b .\n\t" : : "r" (at91_shdwc.mpddrc_base), "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF), "r" (at91_shdwc.shdwc_base), "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW) : "r6"); } static int at91_poweroff_get_wakeup_mode(struct device_node *np) { const char *pm; unsigned int i; int err; err = of_property_read_string(np, "atmel,wakeup-mode", &pm); if (err < 0) return AT91_SHDW_WKMODE0_ANYLEVEL; for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++) if (!strcasecmp(pm, shdwc_wakeup_modes[i])) return i; return -ENODEV; } static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; int wakeup_mode; u32 mode = 0, tmp; wakeup_mode = at91_poweroff_get_wakeup_mode(np); if (wakeup_mode < 0) { dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n"); return; } if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) { if (tmp > AT91_SHDW_CPTWK0_MAX) { dev_warn(&pdev->dev, "shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n", tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX); tmp = AT91_SHDW_CPTWK0_MAX; } mode |= AT91_SHDW_CPTWK0_(tmp); } if (of_property_read_bool(np, "atmel,wakeup-rtc-timer")) mode |= AT91_SHDW_RTCWKEN; if (of_property_read_bool(np, "atmel,wakeup-rtt-timer")) mode |= AT91_SHDW_RTTWKEN; writel(wakeup_mode | mode, at91_shdwc.shdwc_base + AT91_SHDW_MR); } static int at91_poweroff_probe(struct platform_device *pdev) { struct device_node *np; u32 ddr_type; int ret; at91_shdwc.shdwc_base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(at91_shdwc.shdwc_base)) return PTR_ERR(at91_shdwc.shdwc_base); at91_shdwc.sclk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(at91_shdwc.sclk)) return PTR_ERR(at91_shdwc.sclk); ret = clk_prepare_enable(at91_shdwc.sclk); if (ret) { dev_err(&pdev->dev, "Could not enable slow clock\n"); return ret; } at91_wakeup_status(pdev); if (pdev->dev.of_node) at91_poweroff_dt_set_wakeup_mode(pdev); np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc"); if (np) { at91_shdwc.mpddrc_base = of_iomap(np, 0); of_node_put(np); if (!at91_shdwc.mpddrc_base) { ret = -ENOMEM; goto clk_disable; } ddr_type = readl(at91_shdwc.mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD; if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 && ddr_type != AT91_DDRSDRC_MD_LPDDR3) { iounmap(at91_shdwc.mpddrc_base); at91_shdwc.mpddrc_base = NULL; } } pm_power_off = at91_poweroff; return 0; clk_disable: clk_disable_unprepare(at91_shdwc.sclk); return ret; } static void at91_poweroff_remove(struct platform_device *pdev) { if (pm_power_off == at91_poweroff) pm_power_off = NULL; if (at91_shdwc.mpddrc_base) iounmap(at91_shdwc.mpddrc_base); clk_disable_unprepare(at91_shdwc.sclk); } static const struct of_device_id at91_poweroff_of_match[] = { { .compatible = "atmel,at91sam9260-shdwc", }, { .compatible = "atmel,at91sam9rl-shdwc", }, { .compatible = "atmel,at91sam9x5-shdwc", }, { /*sentinel*/ } }; MODULE_DEVICE_TABLE(of, at91_poweroff_of_match); static struct platform_driver at91_poweroff_driver = { .probe = at91_poweroff_probe, .remove_new = at91_poweroff_remove, .driver = { .name = "at91-poweroff", .of_match_table = at91_poweroff_of_match, }, }; module_platform_driver(at91_poweroff_driver); MODULE_AUTHOR("Atmel Corporation"); MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs"); MODULE_LICENSE("GPL v2"); |