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380 lines
9.5 KiB
380 lines
9.5 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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// |
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// Copyright 2008 Openmoko, Inc. |
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// Copyright 2008 Simtec Electronics |
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// Ben Dooks <[email protected]> |
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// http://armlinux.simtec.co.uk/ |
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// |
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// S3C series GPIO PM code |
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#include <linux/kernel.h> |
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#include <linux/device.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/gpio.h> |
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#include "gpio-samsung.h" |
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#include "gpio-core.h" |
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#include "pm.h" |
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/* PM GPIO helpers */ |
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#define OFFS_CON (0x00) |
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#define OFFS_DAT (0x04) |
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#define OFFS_UP (0x08) |
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static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip) |
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{ |
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chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); |
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chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); |
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} |
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static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip) |
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{ |
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void __iomem *base = chip->base; |
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u32 old_gpcon = __raw_readl(base + OFFS_CON); |
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u32 old_gpdat = __raw_readl(base + OFFS_DAT); |
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u32 gps_gpcon = chip->pm_save[0]; |
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u32 gps_gpdat = chip->pm_save[1]; |
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u32 gpcon; |
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/* GPACON only has one bit per control / data and no PULLUPs. |
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* GPACON[x] = 0 => Output, 1 => SFN */ |
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/* first set all SFN bits to SFN */ |
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gpcon = old_gpcon | gps_gpcon; |
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__raw_writel(gpcon, base + OFFS_CON); |
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/* now set all the other bits */ |
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__raw_writel(gps_gpdat, base + OFFS_DAT); |
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__raw_writel(gps_gpcon, base + OFFS_CON); |
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S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", |
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chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); |
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} |
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struct samsung_gpio_pm samsung_gpio_pm_1bit = { |
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.save = samsung_gpio_pm_1bit_save, |
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.resume = samsung_gpio_pm_1bit_resume, |
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}; |
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static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip) |
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{ |
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chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); |
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chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); |
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chip->pm_save[2] = __raw_readl(chip->base + OFFS_UP); |
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} |
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/* Test whether the given masked+shifted bits of an GPIO configuration |
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* are one of the SFN (special function) modes. */ |
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static inline int is_sfn(unsigned long con) |
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{ |
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return con >= 2; |
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} |
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/* Test if the given masked+shifted GPIO configuration is an input */ |
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static inline int is_in(unsigned long con) |
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{ |
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return con == 0; |
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} |
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/* Test if the given masked+shifted GPIO configuration is an output */ |
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static inline int is_out(unsigned long con) |
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{ |
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return con == 1; |
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} |
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/** |
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* samsung_gpio_pm_2bit_resume() - restore the given GPIO bank |
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* @chip: The chip information to resume. |
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* |
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* Restore one of the GPIO banks that was saved during suspend. This is |
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* not as simple as once thought, due to the possibility of glitches |
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* from the order that the CON and DAT registers are set in. |
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* |
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* The three states the pin can be are {IN,OUT,SFN} which gives us 9 |
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* combinations of changes to check. Three of these, if the pin stays |
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* in the same configuration can be discounted. This leaves us with |
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* the following: |
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* |
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* { IN => OUT } Change DAT first |
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* { IN => SFN } Change CON first |
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* { OUT => SFN } Change CON first, so new data will not glitch |
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* { OUT => IN } Change CON first, so new data will not glitch |
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* { SFN => IN } Change CON first |
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* { SFN => OUT } Change DAT first, so new data will not glitch [1] |
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* |
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* We do not currently deal with the UP registers as these control |
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* weak resistors, so a small delay in change should not need to bring |
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* these into the calculations. |
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* |
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* [1] this assumes that writing to a pin DAT whilst in SFN will set the |
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* state for when it is next output. |
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*/ |
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static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip) |
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{ |
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void __iomem *base = chip->base; |
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u32 old_gpcon = __raw_readl(base + OFFS_CON); |
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u32 old_gpdat = __raw_readl(base + OFFS_DAT); |
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u32 gps_gpcon = chip->pm_save[0]; |
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u32 gps_gpdat = chip->pm_save[1]; |
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u32 gpcon, old, new, mask; |
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u32 change_mask = 0x0; |
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int nr; |
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/* restore GPIO pull-up settings */ |
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__raw_writel(chip->pm_save[2], base + OFFS_UP); |
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/* Create a change_mask of all the items that need to have |
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* their CON value changed before their DAT value, so that |
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* we minimise the work between the two settings. |
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*/ |
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for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) { |
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old = (old_gpcon & mask) >> nr; |
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new = (gps_gpcon & mask) >> nr; |
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/* If there is no change, then skip */ |
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if (old == new) |
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continue; |
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/* If both are special function, then skip */ |
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if (is_sfn(old) && is_sfn(new)) |
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continue; |
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/* Change is IN => OUT, do not change now */ |
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if (is_in(old) && is_out(new)) |
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continue; |
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/* Change is SFN => OUT, do not change now */ |
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if (is_sfn(old) && is_out(new)) |
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continue; |
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/* We should now be at the case of IN=>SFN, |
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* OUT=>SFN, OUT=>IN, SFN=>IN. */ |
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change_mask |= mask; |
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} |
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/* Write the new CON settings */ |
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gpcon = old_gpcon & ~change_mask; |
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gpcon |= gps_gpcon & change_mask; |
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__raw_writel(gpcon, base + OFFS_CON); |
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/* Now change any items that require DAT,CON */ |
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__raw_writel(gps_gpdat, base + OFFS_DAT); |
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__raw_writel(gps_gpcon, base + OFFS_CON); |
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S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", |
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chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); |
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} |
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struct samsung_gpio_pm samsung_gpio_pm_2bit = { |
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.save = samsung_gpio_pm_2bit_save, |
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.resume = samsung_gpio_pm_2bit_resume, |
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}; |
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#if defined(CONFIG_ARCH_S3C64XX) |
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static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip) |
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{ |
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chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON); |
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chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT); |
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chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP); |
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if (chip->chip.ngpio > 8) |
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chip->pm_save[0] = __raw_readl(chip->base - 4); |
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} |
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static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon) |
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{ |
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u32 old, new, mask; |
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u32 change_mask = 0x0; |
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int nr; |
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for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) { |
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old = (old_gpcon & mask) >> nr; |
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new = (gps_gpcon & mask) >> nr; |
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/* If there is no change, then skip */ |
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if (old == new) |
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continue; |
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/* If both are special function, then skip */ |
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if (is_sfn(old) && is_sfn(new)) |
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continue; |
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/* Change is IN => OUT, do not change now */ |
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if (is_in(old) && is_out(new)) |
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continue; |
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/* Change is SFN => OUT, do not change now */ |
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if (is_sfn(old) && is_out(new)) |
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continue; |
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/* We should now be at the case of IN=>SFN, |
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* OUT=>SFN, OUT=>IN, SFN=>IN. */ |
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change_mask |= mask; |
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} |
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return change_mask; |
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} |
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static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index) |
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{ |
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void __iomem *con = chip->base + (index * 4); |
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u32 old_gpcon = __raw_readl(con); |
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u32 gps_gpcon = chip->pm_save[index + 1]; |
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u32 gpcon, mask; |
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mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon); |
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gpcon = old_gpcon & ~mask; |
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gpcon |= gps_gpcon & mask; |
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__raw_writel(gpcon, con); |
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} |
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static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip) |
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{ |
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void __iomem *base = chip->base; |
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u32 old_gpcon[2]; |
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u32 old_gpdat = __raw_readl(base + OFFS_DAT); |
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u32 gps_gpdat = chip->pm_save[2]; |
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/* First, modify the CON settings */ |
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old_gpcon[0] = 0; |
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old_gpcon[1] = __raw_readl(base + OFFS_CON); |
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samsung_gpio_pm_4bit_con(chip, 0); |
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if (chip->chip.ngpio > 8) { |
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old_gpcon[0] = __raw_readl(base - 4); |
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samsung_gpio_pm_4bit_con(chip, -1); |
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} |
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/* Now change the configurations that require DAT,CON */ |
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__raw_writel(chip->pm_save[2], base + OFFS_DAT); |
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__raw_writel(chip->pm_save[1], base + OFFS_CON); |
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if (chip->chip.ngpio > 8) |
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__raw_writel(chip->pm_save[0], base - 4); |
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__raw_writel(chip->pm_save[2], base + OFFS_DAT); |
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__raw_writel(chip->pm_save[3], base + OFFS_UP); |
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if (chip->chip.ngpio > 8) { |
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S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n", |
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chip->chip.label, old_gpcon[0], old_gpcon[1], |
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__raw_readl(base - 4), |
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__raw_readl(base + OFFS_CON), |
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old_gpdat, gps_gpdat); |
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} else |
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S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n", |
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chip->chip.label, old_gpcon[1], |
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__raw_readl(base + OFFS_CON), |
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old_gpdat, gps_gpdat); |
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} |
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struct samsung_gpio_pm samsung_gpio_pm_4bit = { |
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.save = samsung_gpio_pm_4bit_save, |
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.resume = samsung_gpio_pm_4bit_resume, |
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}; |
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#endif /* CONFIG_ARCH_S3C64XX */ |
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/** |
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* samsung_pm_save_gpio() - save gpio chip data for suspend |
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* @ourchip: The chip for suspend. |
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*/ |
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static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip) |
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{ |
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struct samsung_gpio_pm *pm = ourchip->pm; |
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if (pm == NULL || pm->save == NULL) |
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S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); |
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else |
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pm->save(ourchip); |
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} |
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/** |
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* samsung_pm_save_gpios() - Save the state of the GPIO banks. |
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* |
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* For all the GPIO banks, save the state of each one ready for going |
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* into a suspend mode. |
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*/ |
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void samsung_pm_save_gpios(void) |
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{ |
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struct samsung_gpio_chip *ourchip; |
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unsigned int gpio_nr; |
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for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
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ourchip = samsung_gpiolib_getchip(gpio_nr); |
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if (!ourchip) { |
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gpio_nr++; |
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continue; |
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} |
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samsung_pm_save_gpio(ourchip); |
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S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n", |
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ourchip->chip.label, |
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ourchip->pm_save[0], |
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ourchip->pm_save[1], |
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ourchip->pm_save[2], |
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ourchip->pm_save[3]); |
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gpio_nr += ourchip->chip.ngpio; |
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gpio_nr += CONFIG_S3C_GPIO_SPACE; |
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} |
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} |
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/** |
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* samsung_pm_resume_gpio() - restore gpio chip data after suspend |
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* @ourchip: The suspended chip. |
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*/ |
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static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip) |
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{ |
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struct samsung_gpio_pm *pm = ourchip->pm; |
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if (pm == NULL || pm->resume == NULL) |
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S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); |
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else |
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pm->resume(ourchip); |
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} |
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void samsung_pm_restore_gpios(void) |
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{ |
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struct samsung_gpio_chip *ourchip; |
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unsigned int gpio_nr; |
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for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { |
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ourchip = samsung_gpiolib_getchip(gpio_nr); |
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if (!ourchip) { |
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gpio_nr++; |
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continue; |
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} |
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samsung_pm_resume_gpio(ourchip); |
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gpio_nr += ourchip->chip.ngpio; |
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gpio_nr += CONFIG_S3C_GPIO_SPACE; |
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} |
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}
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