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239 lines
6.2 KiB
239 lines
6.2 KiB
/* |
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* Atmel AT91 SAM9 SoCs reset code |
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* |
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* Copyright (C) 2007 Atmel Corporation. |
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* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <[email protected]> |
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* Copyright (C) 2014 Free Electrons |
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* |
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* This file is licensed under the terms of the GNU General Public |
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* License version 2. This program is licensed "as is" without any |
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* warranty of any kind, whether express or implied. |
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*/ |
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#include <linux/clk.h> |
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#include <linux/io.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/of_address.h> |
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#include <linux/platform_device.h> |
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#include <linux/printk.h> |
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#include <soc/at91/at91sam9_ddrsdr.h> |
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#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */ |
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#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */ |
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#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */ |
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#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */ |
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#define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */ |
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#define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */ |
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#define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */ |
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#define AT91_SHDW_CPTWK0_(x) ((x) << 4) |
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#define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */ |
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#define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */ |
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#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */ |
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#define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */ |
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#define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */ |
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#define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */ |
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enum wakeup_type { |
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AT91_SHDW_WKMODE0_NONE = 0, |
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AT91_SHDW_WKMODE0_HIGH = 1, |
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AT91_SHDW_WKMODE0_LOW = 2, |
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AT91_SHDW_WKMODE0_ANYLEVEL = 3, |
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}; |
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static const char *shdwc_wakeup_modes[] = { |
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[AT91_SHDW_WKMODE0_NONE] = "none", |
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[AT91_SHDW_WKMODE0_HIGH] = "high", |
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[AT91_SHDW_WKMODE0_LOW] = "low", |
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[AT91_SHDW_WKMODE0_ANYLEVEL] = "any", |
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}; |
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static struct shdwc { |
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struct clk *sclk; |
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void __iomem *shdwc_base; |
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void __iomem *mpddrc_base; |
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} at91_shdwc; |
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static void __init at91_wakeup_status(struct platform_device *pdev) |
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{ |
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const char *reason; |
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u32 reg = readl(at91_shdwc.shdwc_base + AT91_SHDW_SR); |
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/* Simple power-on, just bail out */ |
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if (!reg) |
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return; |
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if (reg & AT91_SHDW_RTTWK) |
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reason = "RTT"; |
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else if (reg & AT91_SHDW_RTCWK) |
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reason = "RTC"; |
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else |
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reason = "unknown"; |
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dev_info(&pdev->dev, "Wake-Up source: %s\n", reason); |
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} |
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static void at91_poweroff(void) |
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{ |
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asm volatile( |
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/* Align to cache lines */ |
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".balign 32\n\t" |
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/* Ensure AT91_SHDW_CR is in the TLB by reading it */ |
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" ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" |
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/* Power down SDRAM0 */ |
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" tst %0, #0\n\t" |
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" beq 1f\n\t" |
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" str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" |
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/* Shutdown CPU */ |
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"1: str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" |
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" b .\n\t" |
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: |
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: "r" (at91_shdwc.mpddrc_base), |
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"r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF), |
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"r" (at91_shdwc.shdwc_base), |
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"r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW) |
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: "r6"); |
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} |
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static int at91_poweroff_get_wakeup_mode(struct device_node *np) |
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{ |
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const char *pm; |
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unsigned int i; |
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int err; |
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err = of_property_read_string(np, "atmel,wakeup-mode", &pm); |
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if (err < 0) |
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return AT91_SHDW_WKMODE0_ANYLEVEL; |
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for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++) |
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if (!strcasecmp(pm, shdwc_wakeup_modes[i])) |
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return i; |
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return -ENODEV; |
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} |
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static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev) |
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{ |
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struct device_node *np = pdev->dev.of_node; |
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int wakeup_mode; |
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u32 mode = 0, tmp; |
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wakeup_mode = at91_poweroff_get_wakeup_mode(np); |
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if (wakeup_mode < 0) { |
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dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n"); |
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return; |
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} |
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if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) { |
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if (tmp > AT91_SHDW_CPTWK0_MAX) { |
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dev_warn(&pdev->dev, |
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"shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n", |
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tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX); |
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tmp = AT91_SHDW_CPTWK0_MAX; |
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} |
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mode |= AT91_SHDW_CPTWK0_(tmp); |
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} |
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if (of_property_read_bool(np, "atmel,wakeup-rtc-timer")) |
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mode |= AT91_SHDW_RTCWKEN; |
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if (of_property_read_bool(np, "atmel,wakeup-rtt-timer")) |
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mode |= AT91_SHDW_RTTWKEN; |
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writel(wakeup_mode | mode, at91_shdwc.shdwc_base + AT91_SHDW_MR); |
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} |
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static int __init at91_poweroff_probe(struct platform_device *pdev) |
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{ |
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struct resource *res; |
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struct device_node *np; |
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u32 ddr_type; |
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int ret; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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at91_shdwc.shdwc_base = devm_ioremap_resource(&pdev->dev, res); |
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if (IS_ERR(at91_shdwc.shdwc_base)) |
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return PTR_ERR(at91_shdwc.shdwc_base); |
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at91_shdwc.sclk = devm_clk_get(&pdev->dev, NULL); |
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if (IS_ERR(at91_shdwc.sclk)) |
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return PTR_ERR(at91_shdwc.sclk); |
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ret = clk_prepare_enable(at91_shdwc.sclk); |
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if (ret) { |
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dev_err(&pdev->dev, "Could not enable slow clock\n"); |
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return ret; |
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} |
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at91_wakeup_status(pdev); |
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if (pdev->dev.of_node) |
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at91_poweroff_dt_set_wakeup_mode(pdev); |
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np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc"); |
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if (np) { |
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at91_shdwc.mpddrc_base = of_iomap(np, 0); |
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of_node_put(np); |
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if (!at91_shdwc.mpddrc_base) { |
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ret = -ENOMEM; |
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goto clk_disable; |
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} |
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ddr_type = readl(at91_shdwc.mpddrc_base + AT91_DDRSDRC_MDR) & |
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AT91_DDRSDRC_MD; |
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if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 && |
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ddr_type != AT91_DDRSDRC_MD_LPDDR3) { |
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iounmap(at91_shdwc.mpddrc_base); |
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at91_shdwc.mpddrc_base = NULL; |
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} |
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} |
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pm_power_off = at91_poweroff; |
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return 0; |
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clk_disable: |
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clk_disable_unprepare(at91_shdwc.sclk); |
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return ret; |
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} |
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static int __exit at91_poweroff_remove(struct platform_device *pdev) |
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{ |
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if (pm_power_off == at91_poweroff) |
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pm_power_off = NULL; |
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if (at91_shdwc.mpddrc_base) |
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iounmap(at91_shdwc.mpddrc_base); |
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clk_disable_unprepare(at91_shdwc.sclk); |
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return 0; |
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} |
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static const struct of_device_id at91_poweroff_of_match[] = { |
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{ .compatible = "atmel,at91sam9260-shdwc", }, |
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{ .compatible = "atmel,at91sam9rl-shdwc", }, |
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{ .compatible = "atmel,at91sam9x5-shdwc", }, |
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{ /*sentinel*/ } |
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}; |
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MODULE_DEVICE_TABLE(of, at91_poweroff_of_match); |
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static struct platform_driver at91_poweroff_driver = { |
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.remove = __exit_p(at91_poweroff_remove), |
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.driver = { |
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.name = "at91-poweroff", |
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.of_match_table = at91_poweroff_of_match, |
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}, |
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}; |
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module_platform_driver_probe(at91_poweroff_driver, at91_poweroff_probe); |
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MODULE_AUTHOR("Atmel Corporation"); |
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MODULE_DESCRIPTION("Shutdown driver for Atmel SoCs"); |
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MODULE_LICENSE("GPL v2");
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