1 /* 2 * Atmel AT91 SAM9 SoCs reset code 3 * 4 * Copyright (C) 2007 Atmel Corporation. 5 * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> 6 * Copyright (C) 2014 Free Electrons 7 * 8 * This file is licensed under the terms of the GNU General Public 9 * License version 2. This program is licensed "as is" without any 10 * warranty of any kind, whether express or implied. 11 */ 12 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/of.h> 16 #include <linux/platform_device.h> 17 #include <linux/printk.h> 18 19 #define AT91_SHDW_CR 0x00 /* Shut Down Control Register */ 20 #define AT91_SHDW_SHDW BIT(0) /* Shut Down command */ 21 #define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */ 22 23 #define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */ 24 #define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */ 25 #define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */ 26 #define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */ 27 #define AT91_SHDW_CPTWK0_(x) ((x) << 4) 28 #define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */ 29 #define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */ 30 31 #define AT91_SHDW_SR 0x08 /* Shut Down Status Register */ 32 #define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */ 33 #define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */ 34 #define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */ 35 36 enum wakeup_type { 37 AT91_SHDW_WKMODE0_NONE = 0, 38 AT91_SHDW_WKMODE0_HIGH = 1, 39 AT91_SHDW_WKMODE0_LOW = 2, 40 AT91_SHDW_WKMODE0_ANYLEVEL = 3, 41 }; 42 43 static const char *shdwc_wakeup_modes[] = { 44 [AT91_SHDW_WKMODE0_NONE] = "none", 45 [AT91_SHDW_WKMODE0_HIGH] = "high", 46 [AT91_SHDW_WKMODE0_LOW] = "low", 47 [AT91_SHDW_WKMODE0_ANYLEVEL] = "any", 48 }; 49 50 static void __iomem *at91_shdwc_base; 51 52 static void __init at91_wakeup_status(void) 53 { 54 u32 reg = readl(at91_shdwc_base + AT91_SHDW_SR); 55 char *reason = "unknown"; 56 57 /* Simple power-on, just bail out */ 58 if (!reg) 59 return; 60 61 if (reg & AT91_SHDW_RTTWK) 62 reason = "RTT"; 63 else if (reg & AT91_SHDW_RTCWK) 64 reason = "RTC"; 65 66 pr_info("AT91: Wake-Up source: %s\n", reason); 67 } 68 69 static void at91_poweroff(void) 70 { 71 writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR); 72 } 73 74 const enum wakeup_type at91_poweroff_get_wakeup_mode(struct device_node *np) 75 { 76 const char *pm; 77 int err, i; 78 79 err = of_property_read_string(np, "atmel,wakeup-mode", &pm); 80 if (err < 0) 81 return AT91_SHDW_WKMODE0_ANYLEVEL; 82 83 for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++) 84 if (!strcasecmp(pm, shdwc_wakeup_modes[i])) 85 return i; 86 87 return -ENODEV; 88 } 89 90 static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev) 91 { 92 struct device_node *np = pdev->dev.of_node; 93 enum wakeup_type wakeup_mode; 94 u32 mode = 0, tmp; 95 96 wakeup_mode = at91_poweroff_get_wakeup_mode(np); 97 if (wakeup_mode < 0) { 98 dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n"); 99 return; 100 } 101 102 if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) { 103 if (tmp > AT91_SHDW_CPTWK0_MAX) { 104 dev_warn(&pdev->dev, 105 "shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n", 106 tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX); 107 tmp = AT91_SHDW_CPTWK0_MAX; 108 } 109 mode |= AT91_SHDW_CPTWK0_(tmp); 110 } 111 112 if (of_property_read_bool(np, "atmel,wakeup-rtc-timer")) 113 mode |= AT91_SHDW_RTCWKEN; 114 115 if (of_property_read_bool(np, "atmel,wakeup-rtt-timer")) 116 mode |= AT91_SHDW_RTTWKEN; 117 118 writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR); 119 } 120 121 static int at91_poweroff_probe(struct platform_device *pdev) 122 { 123 struct resource *res; 124 125 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 126 at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res); 127 if (IS_ERR(at91_shdwc_base)) { 128 dev_err(&pdev->dev, "Could not map reset controller address\n"); 129 return PTR_ERR(at91_shdwc_base); 130 } 131 132 at91_wakeup_status(); 133 134 if (pdev->dev.of_node) 135 at91_poweroff_dt_set_wakeup_mode(pdev); 136 137 pm_power_off = at91_poweroff; 138 139 return 0; 140 } 141 142 static struct of_device_id at91_poweroff_of_match[] = { 143 { .compatible = "atmel,at91sam9260-shdwc", }, 144 { .compatible = "atmel,at91sam9rl-shdwc", }, 145 { .compatible = "atmel,at91sam9x5-shdwc", }, 146 { /*sentinel*/ } 147 }; 148 149 static struct platform_driver at91_poweroff_driver = { 150 .probe = at91_poweroff_probe, 151 .driver = { 152 .name = "at91-poweroff", 153 .of_match_table = at91_poweroff_of_match, 154 }, 155 }; 156 module_platform_driver(at91_poweroff_driver); 157