diff options
| -rw-r--r-- | drivers/pinctrl/pinctrl-samsung.c | 148 | ||||
| -rw-r--r-- | drivers/pinctrl/pinctrl-samsung.h | 5 |
2 files changed, 153 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-samsung.c b/drivers/pinctrl/pinctrl-samsung.c index 055d016..15db258 100644 --- a/drivers/pinctrl/pinctrl-samsung.c +++ b/drivers/pinctrl/pinctrl-samsung.c @@ -28,6 +28,7 @@ #include <linux/gpio.h> #include <linux/irqdomain.h> #include <linux/spinlock.h> +#include <linux/syscore_ops.h> #include "core.h" #include "pinctrl-samsung.h" @@ -48,6 +49,9 @@ static struct pin_config { { "samsung,pin-pud-pdn", PINCFG_TYPE_PUD_PDN }, }; +/* Global list of devices (struct samsung_pinctrl_drv_data) */ +LIST_HEAD(drvdata_list); + static unsigned int pin_base; static inline struct samsung_pin_bank *gc_to_pin_bank(struct gpio_chip *gc) @@ -956,9 +960,145 @@ static int samsung_pinctrl_probe(struct platform_device *pdev) ctrl->eint_wkup_init(drvdata); platform_set_drvdata(pdev, drvdata); + + /* Add to the global list */ + list_add_tail(&drvdata->node, &drvdata_list); + return 0; } +#ifdef CONFIG_PM + +/** + * samsung_pinctrl_suspend_dev - save pinctrl state for suspend for a device + * + * Save data for all banks handled by this device. + */ +static void samsung_pinctrl_suspend_dev( + struct samsung_pinctrl_drv_data *drvdata) +{ + struct samsung_pin_ctrl *ctrl = drvdata->ctrl; + void __iomem *virt_base = drvdata->virt_base; + int i; + + for (i = 0; i < ctrl->nr_banks; i++) { + struct samsung_pin_bank *bank = &ctrl->pin_banks[i]; + void __iomem *reg = virt_base + bank->pctl_offset; + + u8 *offs = bank->type->reg_offset; + u8 *widths = bank->type->fld_width; + enum pincfg_type type; + + /* Registers without a powerdown config aren't lost */ + if (!widths[PINCFG_TYPE_CON_PDN]) + continue; + + for (type = 0; type < PINCFG_TYPE_NUM; type++) + if (widths[type]) + bank->pm_save[type] = readl(reg + offs[type]); + + if (widths[PINCFG_TYPE_FUNC] * bank->nr_pins > 32) { + /* Some banks have two config registers */ + bank->pm_save[PINCFG_TYPE_NUM] = + readl(reg + offs[PINCFG_TYPE_FUNC] + 4); + pr_debug("Save %s @ %p (con %#010x %08x)\n", + bank->name, reg, + bank->pm_save[PINCFG_TYPE_FUNC], + bank->pm_save[PINCFG_TYPE_NUM]); + } else { + pr_debug("Save %s @ %p (con %#010x)\n", bank->name, + reg, bank->pm_save[PINCFG_TYPE_FUNC]); + } + } +} + +/** + * samsung_pinctrl_resume_dev - restore pinctrl state from suspend for a device + * + * Restore one of the banks that was saved during suspend. + * + * We don't bother doing anything complicated to avoid glitching lines since + * we're called before pad retention is turned off. + */ +static void samsung_pinctrl_resume_dev(struct samsung_pinctrl_drv_data *drvdata) +{ + struct samsung_pin_ctrl *ctrl = drvdata->ctrl; + void __iomem *virt_base = drvdata->virt_base; + int i; + + for (i = 0; i < ctrl->nr_banks; i++) { + struct samsung_pin_bank *bank = &ctrl->pin_banks[i]; + void __iomem *reg = virt_base + bank->pctl_offset; + + u8 *offs = bank->type->reg_offset; + u8 *widths = bank->type->fld_width; + enum pincfg_type type; + + /* Registers without a powerdown config aren't lost */ + if (!widths[PINCFG_TYPE_CON_PDN]) + continue; + + if (widths[PINCFG_TYPE_FUNC] * bank->nr_pins > 32) { + /* Some banks have two config registers */ + pr_debug("%s @ %p (con %#010x %08x => %#010x %08x)\n", + bank->name, reg, + readl(reg + offs[PINCFG_TYPE_FUNC]), + readl(reg + offs[PINCFG_TYPE_FUNC] + 4), + bank->pm_save[PINCFG_TYPE_FUNC], + bank->pm_save[PINCFG_TYPE_NUM]); + writel(bank->pm_save[PINCFG_TYPE_NUM], + reg + offs[PINCFG_TYPE_FUNC] + 4); + } else { + pr_debug("%s @ %p (con %#010x => %#010x)\n", bank->name, + reg, readl(reg + offs[PINCFG_TYPE_FUNC]), + bank->pm_save[PINCFG_TYPE_FUNC]); + } + for (type = 0; type < PINCFG_TYPE_NUM; type++) + if (widths[type]) + writel(bank->pm_save[type], reg + offs[type]); + } +} + +/** + * samsung_pinctrl_suspend - save pinctrl state for suspend + * + * Save data for all banks across all devices. + */ +static int samsung_pinctrl_suspend(void) +{ + struct samsung_pinctrl_drv_data *drvdata; + + list_for_each_entry(drvdata, &drvdata_list, node) { + samsung_pinctrl_suspend_dev(drvdata); + } + + return 0; +} + +/** + * samsung_pinctrl_resume - restore pinctrl state for suspend + * + * Restore data for all banks across all devices. + */ +static void samsung_pinctrl_resume(void) +{ + struct samsung_pinctrl_drv_data *drvdata; + + list_for_each_entry_reverse(drvdata, &drvdata_list, node) { + samsung_pinctrl_resume_dev(drvdata); + } +} + +#else +#define samsung_pinctrl_suspend NULL +#define samsung_pinctrl_resume NULL +#endif + +static struct syscore_ops samsung_pinctrl_syscore_ops = { + .suspend = samsung_pinctrl_suspend, + .resume = samsung_pinctrl_resume, +}; + static const struct of_device_id samsung_pinctrl_dt_match[] = { #ifdef CONFIG_PINCTRL_EXYNOS { .compatible = "samsung,exynos4210-pinctrl", @@ -987,6 +1127,14 @@ static struct platform_driver samsung_pinctrl_driver = { static int __init samsung_pinctrl_drv_register(void) { + /* + * Register syscore ops for save/restore of registers across suspend. + * It's important to ensure that this driver is running at an earlier + * initcall level than any arch-specific init calls that install syscore + * ops that turn off pad retention (like exynos_pm_resume). + */ + register_syscore_ops(&samsung_pinctrl_syscore_ops); + return platform_driver_register(&samsung_pinctrl_driver); } postcore_initcall(samsung_pinctrl_drv_register); diff --git a/drivers/pinctrl/pinctrl-samsung.h b/drivers/pinctrl/pinctrl-samsung.h index 7c7f9eb..9f5cc81 100644 --- a/drivers/pinctrl/pinctrl-samsung.h +++ b/drivers/pinctrl/pinctrl-samsung.h @@ -127,6 +127,7 @@ struct samsung_pin_bank_type { * @gpio_chip: GPIO chip of the bank. * @grange: linux gpio pin range supported by this bank. * @slock: spinlock protecting bank registers + * @pm_save: saved register values during suspend */ struct samsung_pin_bank { struct samsung_pin_bank_type *type; @@ -144,6 +145,8 @@ struct samsung_pin_bank { struct gpio_chip gpio_chip; struct pinctrl_gpio_range grange; spinlock_t slock; + + u32 pm_save[PINCFG_TYPE_NUM + 1]; /* +1 to handle double CON registers*/ }; /** @@ -189,6 +192,7 @@ struct samsung_pin_ctrl { /** * struct samsung_pinctrl_drv_data: wrapper for holding driver data together. + * @node: global list node * @virt_base: register base address of the controller. * @dev: device instance representing the controller. * @irq: interrpt number used by the controller to notify gpio interrupts. @@ -201,6 +205,7 @@ struct samsung_pin_ctrl { * @nr_function: number of such pin functions. */ struct samsung_pinctrl_drv_data { + struct list_head node; void __iomem *virt_base; struct device *dev; int irq; |