ARM: OMAP2+: UART: Get context loss count to context restore
authorGovindraj.R <govindraj.raja@ti.com>
Tue, 11 Oct 2011 13:41:27 +0000 (19:11 +0530)
committerKevin Hilman <khilman@ti.com>
Thu, 15 Dec 2011 00:05:22 +0000 (16:05 -0800)
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>
arch/arm/mach-omap2/serial.c
arch/arm/plat-omap/include/plat/omap-serial.h
drivers/tty/serial/omap-serial.c

index b3f3284..78ca7e8 100644 (file)
@@ -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 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
        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);
index 5b913c7..348c9ea 100644 (file)
@@ -62,6 +62,8 @@ struct omap_uart_port_info {
        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 @@ struct uart_omap_port {
        unsigned char           msr_saved_flags;
        char                    name[20];
        unsigned long           port_activity;
+       u32                     context_loss_cnt;
 };
 
 #endif /* __OMAP_SERIAL_H__ */
index f5a5ed6..ea4c24a 100644 (file)
@@ -1440,15 +1440,31 @@ static void serial_omap_restore_context(struct uart_omap_port *up)
 #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;
 }