/* linux/arch/arm/plat-s3c/pm-gpio.c * * Copyright 2008 Openmoko, Inc. * Copyright 2008 Simtec Electronics * Ben Dooks <ben@simtec.co.uk> * http://armlinux.simtec.co.uk/ * * S3C series GPIO PM code * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kernel.h> #include <linux/device.h> #include <linux/init.h> #include <linux/io.h> #include <linux/gpio.h> #include <plat/gpio-core.h> #include <plat/pm.h> /* PM GPIO helpers */ #define OFFS_CON (0x00) #define OFFS_DAT (0x04) #define OFFS_UP (0x08) static void samsung_gpio_pm_1bit_save(struct samsung_gpio_chip *chip) { chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); } static void samsung_gpio_pm_1bit_resume(struct samsung_gpio_chip *chip) { void __iomem *base = chip->base; u32 old_gpcon = __raw_readl(base + OFFS_CON); u32 old_gpdat = __raw_readl(base + OFFS_DAT); u32 gps_gpcon = chip->pm_save[0]; u32 gps_gpdat = chip->pm_save[1]; u32 gpcon; /* GPACON only has one bit per control / data and no PULLUPs. * GPACON[x] = 0 => Output, 1 => SFN */ /* first set all SFN bits to SFN */ gpcon = old_gpcon | gps_gpcon; __raw_writel(gpcon, base + OFFS_CON); /* now set all the other bits */ __raw_writel(gps_gpdat, base + OFFS_DAT); __raw_writel(gps_gpcon, base + OFFS_CON); S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); } struct samsung_gpio_pm samsung_gpio_pm_1bit = { .save = samsung_gpio_pm_1bit_save, .resume = samsung_gpio_pm_1bit_resume, }; static void samsung_gpio_pm_2bit_save(struct samsung_gpio_chip *chip) { chip->pm_save[0] = __raw_readl(chip->base + OFFS_CON); chip->pm_save[1] = __raw_readl(chip->base + OFFS_DAT); chip->pm_save[2] = __raw_readl(chip->base + OFFS_UP); } /* Test whether the given masked+shifted bits of an GPIO configuration * are one of the SFN (special function) modes. */ static inline int is_sfn(unsigned long con) { return con >= 2; } /* Test if the given masked+shifted GPIO configuration is an input */ static inline int is_in(unsigned long con) { return con == 0; } /* Test if the given masked+shifted GPIO configuration is an output */ static inline int is_out(unsigned long con) { return con == 1; } /** * samsung_gpio_pm_2bit_resume() - restore the given GPIO bank * @chip: The chip information to resume. * * Restore one of the GPIO banks that was saved during suspend. This is * not as simple as once thought, due to the possibility of glitches * from the order that the CON and DAT registers are set in. * * The three states the pin can be are {IN,OUT,SFN} which gives us 9 * combinations of changes to check. Three of these, if the pin stays * in the same configuration can be discounted. This leaves us with * the following: * * { IN => OUT } Change DAT first * { IN => SFN } Change CON first * { OUT => SFN } Change CON first, so new data will not glitch * { OUT => IN } Change CON first, so new data will not glitch * { SFN => IN } Change CON first * { SFN => OUT } Change DAT first, so new data will not glitch [1] * * We do not currently deal with the UP registers as these control * weak resistors, so a small delay in change should not need to bring * these into the calculations. * * [1] this assumes that writing to a pin DAT whilst in SFN will set the * state for when it is next output. */ static void samsung_gpio_pm_2bit_resume(struct samsung_gpio_chip *chip) { void __iomem *base = chip->base; u32 old_gpcon = __raw_readl(base + OFFS_CON); u32 old_gpdat = __raw_readl(base + OFFS_DAT); u32 gps_gpcon = chip->pm_save[0]; u32 gps_gpdat = chip->pm_save[1]; u32 gpcon, old, new, mask; u32 change_mask = 0x0; int nr; /* restore GPIO pull-up settings */ __raw_writel(chip->pm_save[2], base + OFFS_UP); /* Create a change_mask of all the items that need to have * their CON value changed before their DAT value, so that * we minimise the work between the two settings. */ for (nr = 0, mask = 0x03; nr < 32; nr += 2, mask <<= 2) { old = (old_gpcon & mask) >> nr; new = (gps_gpcon & mask) >> nr; /* If there is no change, then skip */ if (old == new) continue; /* If both are special function, then skip */ if (is_sfn(old) && is_sfn(new)) continue; /* Change is IN => OUT, do not change now */ if (is_in(old) && is_out(new)) continue; /* Change is SFN => OUT, do not change now */ if (is_sfn(old) && is_out(new)) continue; /* We should now be at the case of IN=>SFN, * OUT=>SFN, OUT=>IN, SFN=>IN. */ change_mask |= mask; } /* Write the new CON settings */ gpcon = old_gpcon & ~change_mask; gpcon |= gps_gpcon & change_mask; __raw_writel(gpcon, base + OFFS_CON); /* Now change any items that require DAT,CON */ __raw_writel(gps_gpdat, base + OFFS_DAT); __raw_writel(gps_gpcon, base + OFFS_CON); S3C_PMDBG("%s: CON %08x => %08x, DAT %08x => %08x\n", chip->chip.label, old_gpcon, gps_gpcon, old_gpdat, gps_gpdat); } struct samsung_gpio_pm samsung_gpio_pm_2bit = { .save = samsung_gpio_pm_2bit_save, .resume = samsung_gpio_pm_2bit_resume, }; #if defined(CONFIG_ARCH_S3C64XX) || defined(CONFIG_PLAT_S5P) static void samsung_gpio_pm_4bit_save(struct samsung_gpio_chip *chip) { chip->pm_save[1] = __raw_readl(chip->base + OFFS_CON); chip->pm_save[2] = __raw_readl(chip->base + OFFS_DAT); chip->pm_save[3] = __raw_readl(chip->base + OFFS_UP); if (chip->chip.ngpio > 8) chip->pm_save[0] = __raw_readl(chip->base - 4); } static u32 samsung_gpio_pm_4bit_mask(u32 old_gpcon, u32 gps_gpcon) { u32 old, new, mask; u32 change_mask = 0x0; int nr; for (nr = 0, mask = 0x0f; nr < 16; nr += 4, mask <<= 4) { old = (old_gpcon & mask) >> nr; new = (gps_gpcon & mask) >> nr; /* If there is no change, then skip */ if (old == new) continue; /* If both are special function, then skip */ if (is_sfn(old) && is_sfn(new)) continue; /* Change is IN => OUT, do not change now */ if (is_in(old) && is_out(new)) continue; /* Change is SFN => OUT, do not change now */ if (is_sfn(old) && is_out(new)) continue; /* We should now be at the case of IN=>SFN, * OUT=>SFN, OUT=>IN, SFN=>IN. */ change_mask |= mask; } return change_mask; } static void samsung_gpio_pm_4bit_con(struct samsung_gpio_chip *chip, int index) { void __iomem *con = chip->base + (index * 4); u32 old_gpcon = __raw_readl(con); u32 gps_gpcon = chip->pm_save[index + 1]; u32 gpcon, mask; mask = samsung_gpio_pm_4bit_mask(old_gpcon, gps_gpcon); gpcon = old_gpcon & ~mask; gpcon |= gps_gpcon & mask; __raw_writel(gpcon, con); } static void samsung_gpio_pm_4bit_resume(struct samsung_gpio_chip *chip) { void __iomem *base = chip->base; u32 old_gpcon[2]; u32 old_gpdat = __raw_readl(base + OFFS_DAT); u32 gps_gpdat = chip->pm_save[2]; /* First, modify the CON settings */ old_gpcon[0] = 0; old_gpcon[1] = __raw_readl(base + OFFS_CON); samsung_gpio_pm_4bit_con(chip, 0); if (chip->chip.ngpio > 8) { old_gpcon[0] = __raw_readl(base - 4); samsung_gpio_pm_4bit_con(chip, -1); } /* Now change the configurations that require DAT,CON */ __raw_writel(chip->pm_save[2], base + OFFS_DAT); __raw_writel(chip->pm_save[1], base + OFFS_CON); if (chip->chip.ngpio > 8) __raw_writel(chip->pm_save[0], base - 4); __raw_writel(chip->pm_save[2], base + OFFS_DAT); __raw_writel(chip->pm_save[3], base + OFFS_UP); if (chip->chip.ngpio > 8) { S3C_PMDBG("%s: CON4 %08x,%08x => %08x,%08x, DAT %08x => %08x\n", chip->chip.label, old_gpcon[0], old_gpcon[1], __raw_readl(base - 4), __raw_readl(base + OFFS_CON), old_gpdat, gps_gpdat); } else S3C_PMDBG("%s: CON4 %08x => %08x, DAT %08x => %08x\n", chip->chip.label, old_gpcon[1], __raw_readl(base + OFFS_CON), old_gpdat, gps_gpdat); } struct samsung_gpio_pm samsung_gpio_pm_4bit = { .save = samsung_gpio_pm_4bit_save, .resume = samsung_gpio_pm_4bit_resume, }; #endif /* CONFIG_ARCH_S3C64XX || CONFIG_PLAT_S5P */ /** * samsung_pm_save_gpio() - save gpio chip data for suspend * @ourchip: The chip for suspend. */ static void samsung_pm_save_gpio(struct samsung_gpio_chip *ourchip) { struct samsung_gpio_pm *pm = ourchip->pm; if (pm == NULL || pm->save == NULL) S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); else pm->save(ourchip); } /** * samsung_pm_save_gpios() - Save the state of the GPIO banks. * * For all the GPIO banks, save the state of each one ready for going * into a suspend mode. */ void samsung_pm_save_gpios(void) { struct samsung_gpio_chip *ourchip; unsigned int gpio_nr; for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { ourchip = samsung_gpiolib_getchip(gpio_nr); if (!ourchip) { gpio_nr++; continue; } samsung_pm_save_gpio(ourchip); S3C_PMDBG("%s: save %08x,%08x,%08x,%08x\n", ourchip->chip.label, ourchip->pm_save[0], ourchip->pm_save[1], ourchip->pm_save[2], ourchip->pm_save[3]); gpio_nr += ourchip->chip.ngpio; gpio_nr += CONFIG_S3C_GPIO_SPACE; } } /** * samsung_pm_resume_gpio() - restore gpio chip data after suspend * @ourchip: The suspended chip. */ static void samsung_pm_resume_gpio(struct samsung_gpio_chip *ourchip) { struct samsung_gpio_pm *pm = ourchip->pm; if (pm == NULL || pm->resume == NULL) S3C_PMDBG("%s: no pm for %s\n", __func__, ourchip->chip.label); else pm->resume(ourchip); } void samsung_pm_restore_gpios(void) { struct samsung_gpio_chip *ourchip; unsigned int gpio_nr; for (gpio_nr = 0; gpio_nr < S3C_GPIO_END;) { ourchip = samsung_gpiolib_getchip(gpio_nr); if (!ourchip) { gpio_nr++; continue; } samsung_pm_resume_gpio(ourchip); gpio_nr += ourchip->chip.ngpio; gpio_nr += CONFIG_S3C_GPIO_SPACE; } }