/* * Atmel AT91 SAM9 SoCs reset code * * Copyright (C) 2007 Atmel Corporation. * Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD * 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 #include #include #include #include #include #include #include #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 = 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");