This adds a pair of context save/restore functions to save/restore the
state of a set of pinctrl registers. The context is lost during rtc only
suspend with ddr in self-refresh on am43xx. Currently the save/restore
is being done unconditionally. This will be optimized later with a
pdata-quirk function which will allow is to save/restore only when doing
the rtc only mode with ddr in self refresh.
Signed-off-by: Keerthy <j-keerthy@xxxxxx>
---
Changes in v2:
* As this is needed only the in the suspend/resume path
removed the cpu_pm notifier and added the save/restore in
the suspend/resume calls.
* Saving/Restoring unconditionally at the moment. This will
be optimized later with the help of a pdata-quirk function.
drivers/pinctrl/pinctrl-single.c | 72 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 71 insertions(+), 1 deletion(-)
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
index a7c5eb3..9c3c005 100644
--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -144,6 +144,7 @@ struct pcs_soc_data {
* struct pcs_device - pinctrl device instance
* @res: resources
* @base: virtual address of the controller
+ * @saved_vals: saved values for the controller
* @size: size of the ioremapped area
* @dev: device entry
* @np: device tree node
@@ -172,11 +173,13 @@ struct pcs_soc_data {
struct pcs_device {
struct resource *res;
void __iomem *base;
+ void *saved_vals;
unsigned size;
struct device *dev;
struct device_node *np;
struct pinctrl_dev *pctl;
unsigned flags;
+#define PCS_CONTEXT_LOSS_OFF (1 << 3)
#define PCS_QUIRK_SHARED_IRQ (1 << 2)
#define PCS_FEAT_IRQ (1 << 1)
#define PCS_FEAT_PINCONF (1 << 0)
@@ -1576,6 +1579,67 @@ static int pcs_irq_init_chained_handler(struct pcs_device *pcs,
}
#ifdef CONFIG_PM
+static int pcs_save_context(struct pcs_device *pcs)
+{
+ int i, mux_bytes;
+ u64 *regsl;
+ u32 *regsw;
+ u16 *regshw;
+
+ mux_bytes = pcs->width / BITS_PER_BYTE;
+
+ if (!pcs->saved_vals)
+ pcs->saved_vals = devm_kzalloc(pcs->dev, pcs->size, GFP_ATOMIC);
+
+ switch (pcs->width) {
+ case 64:
+ regsl = (u64 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ regsl[i] = pcs->read(pcs->base + i * mux_bytes);
+ break;
+ case 32:
+ regsw = (u32 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ regsw[i] = pcs->read(pcs->base + i * mux_bytes);
+ break;
+ case 16:
+ regshw = (u16 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ regshw[i] = pcs->read(pcs->base + i * mux_bytes);
+ break;
+ }
+
+ return 0;
+}
+
+static void pcs_restore_context(struct pcs_device *pcs)
+{
+ int i, mux_bytes;
+ u64 *regsl;
+ u32 *regsw;
+ u16 *regshw;
+
+ mux_bytes = pcs->width / BITS_PER_BYTE;
+
+ switch (pcs->width) {
+ case 64:
+ regsl = (u64 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ pcs->write(regsl[i], pcs->base + i * mux_bytes);
+ break;
+ case 32:
+ regsw = (u32 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ pcs->write(regsw[i], pcs->base + i * mux_bytes);
+ break;
+ case 16:
+ regshw = (u16 *)pcs->saved_vals;
+ for (i = 0; i < pcs->size / mux_bytes; i++)
+ pcs->write(regshw[i], pcs->base + i * mux_bytes);
+ break;
+ }
+}
+
static int pinctrl_single_suspend(struct platform_device *pdev,
pm_message_t state)
{
@@ -1585,6 +1649,9 @@ static int pinctrl_single_suspend(struct platform_device *pdev,
if (!pcs)
return -EINVAL;
+ if (pcs->flags & PCS_CONTEXT_LOSS_OFF)
+ pcs_save_context(pcs);
+
return pinctrl_force_sleep(pcs->pctl);
}
@@ -1596,6 +1663,9 @@ static int pinctrl_single_resume(struct platform_device *pdev)
if (!pcs)
return -EINVAL;
+ if (pcs->flags & PCS_CONTEXT_LOSS_OFF)
+ pcs_restore_context(pcs);
+
return pinctrl_force_default(pcs->pctl);
}
#endif
@@ -1824,7 +1894,7 @@ static int pcs_remove(struct platform_device *pdev)
};
static const struct pcs_soc_data pinctrl_single_am437x = {
- .flags = PCS_QUIRK_SHARED_IRQ,
+ .flags = PCS_QUIRK_SHARED_IRQ | PCS_CONTEXT_LOSS_OFF,
.irq_enable_mask = (1 << 29), /* OMAP_WAKEUP_EN */
.irq_status_mask = (1 << 30), /* OMAP_WAKEUP_EVENT */
};
--
1.9.1
--
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