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path: root/drivers/pinctrl/pinctrl-samsung.c
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Diffstat (limited to 'drivers/pinctrl/pinctrl-samsung.c')
-rw-r--r--drivers/pinctrl/pinctrl-samsung.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-samsung.c b/drivers/pinctrl/pinctrl-samsung.c
index 055d0162098b..63ac22e89678 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 +960,151 @@ 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]);
+ }
+ }
+
+ if (ctrl->suspend)
+ ctrl->suspend(drvdata);
+}
+
+/**
+ * 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;
+
+ if (ctrl->resume)
+ ctrl->resume(drvdata);
+
+ 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 +1133,14 @@ 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);