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457 lines
11 KiB
457 lines
11 KiB
/* |
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* Atmel SAMA5D2-Compatible Shutdown Controller (SHDWC) driver. |
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* Found on some SoCs as the sama5d2 (obviously). |
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* |
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* Copyright (C) 2015 Atmel Corporation, |
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* Nicolas Ferre <[email protected]> |
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* |
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* Evolved from driver at91-poweroff.c. |
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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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* TODO: |
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* - addition to status of other wake-up inputs [1 - 15] |
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* - Analog Comparator wake-up alarm |
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* - Serial RX wake-up alarm |
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* - low power debouncer |
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*/ |
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#include <linux/clk.h> |
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#include <linux/clk/at91_pmc.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 SLOW_CLOCK_FREQ 32768 |
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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 (0xa5UL << 24) /* KEY Password */ |
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#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */ |
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#define AT91_SHDW_WKUPDBC_SHIFT 24 |
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#define AT91_SHDW_WKUPDBC_MASK GENMASK(26, 24) |
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#define AT91_SHDW_WKUPDBC(x) (((x) << AT91_SHDW_WKUPDBC_SHIFT) \ |
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& AT91_SHDW_WKUPDBC_MASK) |
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|
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#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */ |
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#define AT91_SHDW_WKUPIS_SHIFT 16 |
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#define AT91_SHDW_WKUPIS_MASK GENMASK(31, 16) |
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#define AT91_SHDW_WKUPIS(x) ((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \ |
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& AT91_SHDW_WKUPIS_MASK) |
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#define AT91_SHDW_WUIR 0x0c /* Shutdown Wake-up Inputs Register */ |
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#define AT91_SHDW_WKUPEN_MASK GENMASK(15, 0) |
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#define AT91_SHDW_WKUPEN(x) ((1 << (x)) & AT91_SHDW_WKUPEN_MASK) |
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#define AT91_SHDW_WKUPT_SHIFT 16 |
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#define AT91_SHDW_WKUPT_MASK GENMASK(31, 16) |
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#define AT91_SHDW_WKUPT(x) ((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \ |
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& AT91_SHDW_WKUPT_MASK) |
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#define SHDW_WK_PIN(reg, cfg) ((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input)) |
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#define SHDW_RTCWK(reg, cfg) (((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1) |
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#define SHDW_RTTWK(reg, cfg) (((reg) >> ((cfg)->sr_rttwk_shift)) & 0x1) |
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#define SHDW_RTCWKEN(cfg) (1 << ((cfg)->mr_rtcwk_shift)) |
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#define SHDW_RTTWKEN(cfg) (1 << ((cfg)->mr_rttwk_shift)) |
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#define DBC_PERIOD_US(x) DIV_ROUND_UP_ULL((1000000 * (x)), \ |
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SLOW_CLOCK_FREQ) |
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#define SHDW_CFG_NOT_USED (32) |
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struct shdwc_reg_config { |
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u8 wkup_pin_input; |
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u8 mr_rtcwk_shift; |
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u8 mr_rttwk_shift; |
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u8 sr_rtcwk_shift; |
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u8 sr_rttwk_shift; |
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}; |
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struct pmc_reg_config { |
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u8 mckr; |
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}; |
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struct ddrc_reg_config { |
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u32 type_offset; |
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u32 type_mask; |
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}; |
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struct reg_config { |
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struct shdwc_reg_config shdwc; |
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struct pmc_reg_config pmc; |
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struct ddrc_reg_config ddrc; |
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}; |
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struct shdwc { |
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const struct reg_config *rcfg; |
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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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void __iomem *pmc_base; |
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}; |
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/* |
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* Hold configuration here, cannot be more than one instance of the driver |
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* since pm_power_off itself is global. |
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*/ |
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static struct shdwc *at91_shdwc; |
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static const unsigned long long sdwc_dbc_period[] = { |
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0, 3, 32, 512, 4096, 32768, |
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}; |
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static void __init at91_wakeup_status(struct platform_device *pdev) |
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{ |
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struct shdwc *shdw = platform_get_drvdata(pdev); |
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const struct reg_config *rcfg = shdw->rcfg; |
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u32 reg; |
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char *reason = "unknown"; |
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reg = readl(shdw->shdwc_base + AT91_SHDW_SR); |
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dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg); |
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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 (SHDW_WK_PIN(reg, &rcfg->shdwc)) |
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reason = "WKUP pin"; |
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else if (SHDW_RTCWK(reg, &rcfg->shdwc)) |
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reason = "RTC"; |
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else if (SHDW_RTTWK(reg, &rcfg->shdwc)) |
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reason = "RTT"; |
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pr_info("AT91: 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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|
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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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|
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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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/* Switch the master clock source to slow clock. */ |
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"1: ldr r6, [%4, %5]\n\t" |
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" bic r6, r6, #" __stringify(AT91_PMC_CSS) "\n\t" |
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" str r6, [%4, %5]\n\t" |
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/* Wait for clock switch. */ |
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"2: ldr r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t" |
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" tst r6, #" __stringify(AT91_PMC_MCKRDY) "\n\t" |
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" beq 2b\n\t" |
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/* Shutdown CPU */ |
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" 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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"r" (at91_shdwc->pmc_base), |
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"r" (at91_shdwc->rcfg->pmc.mckr) |
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: "r6"); |
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} |
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static u32 at91_shdwc_debouncer_value(struct platform_device *pdev, |
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u32 in_period_us) |
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{ |
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int i; |
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int max_idx = ARRAY_SIZE(sdwc_dbc_period) - 1; |
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unsigned long long period_us; |
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unsigned long long max_period_us = DBC_PERIOD_US(sdwc_dbc_period[max_idx]); |
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if (in_period_us > max_period_us) { |
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dev_warn(&pdev->dev, |
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"debouncer period %u too big, reduced to %llu us\n", |
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in_period_us, max_period_us); |
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return max_idx; |
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} |
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for (i = max_idx - 1; i > 0; i--) { |
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period_us = DBC_PERIOD_US(sdwc_dbc_period[i]); |
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dev_dbg(&pdev->dev, "%s: ref[%d] = %llu\n", |
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__func__, i, period_us); |
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if (in_period_us > period_us) |
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break; |
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} |
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return i + 1; |
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} |
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static u32 at91_shdwc_get_wakeup_input(struct platform_device *pdev, |
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struct device_node *np) |
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{ |
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struct device_node *cnp; |
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u32 wk_input_mask; |
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u32 wuir = 0; |
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u32 wk_input; |
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for_each_child_of_node(np, cnp) { |
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if (of_property_read_u32(cnp, "reg", &wk_input)) { |
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dev_warn(&pdev->dev, "reg property is missing for %pOF\n", |
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cnp); |
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continue; |
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} |
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wk_input_mask = 1 << wk_input; |
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if (!(wk_input_mask & AT91_SHDW_WKUPEN_MASK)) { |
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dev_warn(&pdev->dev, |
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"wake-up input %d out of bounds ignore\n", |
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wk_input); |
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continue; |
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} |
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wuir |= wk_input_mask; |
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if (of_property_read_bool(cnp, "atmel,wakeup-active-high")) |
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wuir |= AT91_SHDW_WKUPT(wk_input); |
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dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n", |
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__func__, wk_input, wuir); |
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} |
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return wuir; |
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} |
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static void at91_shdwc_dt_configure(struct platform_device *pdev) |
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{ |
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struct shdwc *shdw = platform_get_drvdata(pdev); |
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const struct reg_config *rcfg = shdw->rcfg; |
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struct device_node *np = pdev->dev.of_node; |
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u32 mode = 0, tmp, input; |
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if (!np) { |
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dev_err(&pdev->dev, "device node not found\n"); |
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return; |
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} |
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if (!of_property_read_u32(np, "debounce-delay-us", &tmp)) |
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mode |= AT91_SHDW_WKUPDBC(at91_shdwc_debouncer_value(pdev, tmp)); |
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if (of_property_read_bool(np, "atmel,wakeup-rtc-timer")) |
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mode |= SHDW_RTCWKEN(&rcfg->shdwc); |
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if (of_property_read_bool(np, "atmel,wakeup-rtt-timer")) |
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mode |= SHDW_RTTWKEN(&rcfg->shdwc); |
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dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode); |
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writel(mode, shdw->shdwc_base + AT91_SHDW_MR); |
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input = at91_shdwc_get_wakeup_input(pdev, np); |
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writel(input, shdw->shdwc_base + AT91_SHDW_WUIR); |
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} |
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static const struct reg_config sama5d2_reg_config = { |
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.shdwc = { |
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.wkup_pin_input = 0, |
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.mr_rtcwk_shift = 17, |
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.mr_rttwk_shift = SHDW_CFG_NOT_USED, |
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.sr_rtcwk_shift = 5, |
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.sr_rttwk_shift = SHDW_CFG_NOT_USED, |
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}, |
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.pmc = { |
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.mckr = 0x30, |
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}, |
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.ddrc = { |
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.type_offset = AT91_DDRSDRC_MDR, |
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.type_mask = AT91_DDRSDRC_MD |
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}, |
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}; |
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static const struct reg_config sam9x60_reg_config = { |
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.shdwc = { |
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.wkup_pin_input = 0, |
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.mr_rtcwk_shift = 17, |
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.mr_rttwk_shift = 16, |
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.sr_rtcwk_shift = 5, |
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.sr_rttwk_shift = 4, |
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}, |
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.pmc = { |
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.mckr = 0x28, |
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}, |
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.ddrc = { |
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.type_offset = AT91_DDRSDRC_MDR, |
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.type_mask = AT91_DDRSDRC_MD |
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}, |
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}; |
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static const struct reg_config sama7g5_reg_config = { |
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.shdwc = { |
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.wkup_pin_input = 0, |
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.mr_rtcwk_shift = 17, |
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.mr_rttwk_shift = 16, |
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.sr_rtcwk_shift = 5, |
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.sr_rttwk_shift = 4, |
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}, |
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.pmc = { |
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.mckr = 0x28, |
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}, |
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}; |
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static const struct of_device_id at91_shdwc_of_match[] = { |
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{ |
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.compatible = "atmel,sama5d2-shdwc", |
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.data = &sama5d2_reg_config, |
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}, |
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{ |
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.compatible = "microchip,sam9x60-shdwc", |
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.data = &sam9x60_reg_config, |
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}, |
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{ |
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.compatible = "microchip,sama7g5-shdwc", |
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.data = &sama7g5_reg_config, |
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}, { |
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/*sentinel*/ |
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} |
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}; |
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MODULE_DEVICE_TABLE(of, at91_shdwc_of_match); |
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static const struct of_device_id at91_pmc_ids[] = { |
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{ .compatible = "atmel,sama5d2-pmc" }, |
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{ .compatible = "microchip,sam9x60-pmc" }, |
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{ .compatible = "microchip,sama7g5-pmc" }, |
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{ /* Sentinel. */ } |
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}; |
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static int __init at91_shdwc_probe(struct platform_device *pdev) |
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{ |
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struct resource *res; |
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const struct of_device_id *match; |
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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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if (!pdev->dev.of_node) |
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return -ENODEV; |
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if (at91_shdwc) |
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return -EBUSY; |
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at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL); |
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if (!at91_shdwc) |
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return -ENOMEM; |
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platform_set_drvdata(pdev, at91_shdwc); |
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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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match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node); |
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at91_shdwc->rcfg = match->data; |
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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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at91_shdwc_dt_configure(pdev); |
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np = of_find_matching_node(NULL, at91_pmc_ids); |
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if (!np) { |
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ret = -ENODEV; |
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goto clk_disable; |
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} |
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at91_shdwc->pmc_base = of_iomap(np, 0); |
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of_node_put(np); |
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if (!at91_shdwc->pmc_base) { |
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ret = -ENOMEM; |
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goto clk_disable; |
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} |
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if (at91_shdwc->rcfg->ddrc.type_mask) { |
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np = of_find_compatible_node(NULL, NULL, |
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"atmel,sama5d3-ddramc"); |
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if (!np) { |
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ret = -ENODEV; |
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goto unmap; |
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} |
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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 unmap; |
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} |
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ddr_type = readl(at91_shdwc->mpddrc_base + |
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at91_shdwc->rcfg->ddrc.type_offset) & |
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at91_shdwc->rcfg->ddrc.type_mask; |
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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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unmap: |
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iounmap(at91_shdwc->pmc_base); |
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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_shdwc_remove(struct platform_device *pdev) |
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{ |
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struct shdwc *shdw = platform_get_drvdata(pdev); |
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if (pm_power_off == at91_poweroff) |
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pm_power_off = NULL; |
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/* Reset values to disable wake-up features */ |
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writel(0, shdw->shdwc_base + AT91_SHDW_MR); |
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writel(0, shdw->shdwc_base + AT91_SHDW_WUIR); |
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if (shdw->mpddrc_base) |
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iounmap(shdw->mpddrc_base); |
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iounmap(shdw->pmc_base); |
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clk_disable_unprepare(shdw->sclk); |
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return 0; |
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} |
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static struct platform_driver at91_shdwc_driver = { |
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.remove = __exit_p(at91_shdwc_remove), |
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.driver = { |
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.name = "at91-shdwc", |
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.of_match_table = at91_shdwc_of_match, |
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}, |
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}; |
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module_platform_driver_probe(at91_shdwc_driver, at91_shdwc_probe); |
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MODULE_AUTHOR("Nicolas Ferre <[email protected]>"); |
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MODULE_DESCRIPTION("Atmel shutdown controller driver"); |
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MODULE_LICENSE("GPL v2");
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