ARM: OMAP2+: UART: Get context loss count to context restore
Avoid unconditional context restore every time we gate uart
clocks. Check whether context loss happened based on which
we can context restore uart regs from uart_port structure.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index b3f3284..78ca7e8 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -33,6 +33,7 @@
#include <plat/dma.h>
#include <plat/omap_hwmod.h>
#include <plat/omap_device.h>
+#include <plat/omap-pm.h>
#include "prm2xxx_3xxx.h"
#include "pm.h"
@@ -478,6 +479,7 @@
omap_up.dma_enabled = uart->dma_enabled;
omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
omap_up.flags = UPF_BOOT_AUTOCONF;
+ omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
pdata = &omap_up;
pdata_size = sizeof(struct omap_uart_port_info);
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index 5b913c7..348c9ea 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -62,6 +62,8 @@
bool dma_enabled; /* To specify DMA Mode */
unsigned int uartclk; /* UART clock rate */
upf_t flags; /* UPF_* flags */
+
+ int (*get_context_loss_count)(struct device *);
};
struct uart_omap_dma {
@@ -114,6 +116,7 @@
unsigned char msr_saved_flags;
char name[20];
unsigned long port_activity;
+ u32 context_loss_cnt;
};
#endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index f5a5ed6..ea4c24a 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1440,15 +1440,31 @@
#ifdef CONFIG_PM_RUNTIME
static int serial_omap_runtime_suspend(struct device *dev)
{
+ struct uart_omap_port *up = dev_get_drvdata(dev);
+ struct omap_uart_port_info *pdata = dev->platform_data;
+
+ if (!up)
+ return -EINVAL;
+
+ if (pdata->get_context_loss_count)
+ up->context_loss_cnt = pdata->get_context_loss_count(dev);
+
return 0;
}
static int serial_omap_runtime_resume(struct device *dev)
{
struct uart_omap_port *up = dev_get_drvdata(dev);
+ struct omap_uart_port_info *pdata = dev->platform_data;
- if (up)
- serial_omap_restore_context(up);
+ if (up) {
+ if (pdata->get_context_loss_count) {
+ u32 loss_cnt = pdata->get_context_loss_count(dev);
+
+ if (up->context_loss_cnt != loss_cnt)
+ serial_omap_restore_context(up);
+ }
+ }
return 0;
}
