[PATCH v2 12/12] OMAP2: Serial: Add no async wake flag.

[govindraj.raja@ti.com (Govindraj.R)]

For omap2 cpu_idle thread will not be available
and uart_clock cutting happens only in suspend path.

Prior to this patch the uart_clock was cut using prepare/resume
calls since these funcs are no more available with runtime
changes use no_async_wake flag to keep clock active during bootup
otherwise uart port will disabled during boot-up and cannot be
enabled back.
Also based on this flag we can disable uart port during suspend
and enable back during resume.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/mach-omap2/serial.c                  |    7 +++++++
 arch/arm/plat-omap/include/plat/omap-serial.h |    3 +++
 drivers/tty/serial/omap-serial.c              |   14 ++++++++++++++
 3 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index d4ef370..1af9fd5 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -245,6 +245,12 @@ static void omap_uart_wakeup_enable(struct platform_device *pdev, bool enable)
 static void omap_uart_idle_init(struct omap_uart_port_info *uart,
 				unsigned short num)
 {
+	/* On omap2 no cpu_idle and async wakeup from prcm_module.
+	 * This flag can be used to cut clocks only in suspend path.
+	 * to avoid boot break due to aggressive clock cutting from
+	 * omap-serial driver.
+	 */
+	uart->no_async_wake = true;
 	if (cpu_is_omap34xx()) {
 		u32 mod = num > 1 ? OMAP3430_PER_MOD : CORE_MOD;
 		u32 wk_mask = 0;
@@ -266,6 +272,7 @@ static void omap_uart_idle_init(struct omap_uart_port_info *uart,
 			break;
 		}
 		uart->wk_mask = wk_mask;
+		uart->no_async_wake = false;
 	} else if (cpu_is_omap24xx()) {
 		u32 wk_mask = 0;
 		u32 wk_en = PM_WKEN1, wk_st = PM_WKST1;
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index b5117bd..1de5bc4 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -79,6 +79,7 @@ struct omap_uart_port_info {
 	void __iomem *wk_st;
 	void __iomem *wk_en;
 	u32 wk_mask;
+	bool			no_async_wake;
 };
 
 struct uart_omap_dma {
@@ -134,6 +135,8 @@ struct uart_omap_port {
 	unsigned int		errata;
 	void (*enable_wakeup)(struct platform_device *, bool);
 	bool (*chk_wakeup)(struct platform_device *);
+
+	bool			no_async_wake;
 };
 
 #endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index eea478c..59f548f 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1168,6 +1168,13 @@ static int serial_omap_suspend(struct device *dev)
 		uart_suspend_port(&serial_omap_reg, &up->port);
 		console_trylock();
 		serial_omap_pm(&up->port, 3, 0);
+
+		/* OMAP2 dont have cpu_idle thread and async wakeup from prcm.
+		 * For such socs clocks will be kept active from probe and
+		 * cut only in suspend path.
+		 */
+		if (up->no_async_wake)
+			serial_omap_port_disable(up);
 	}
 	return 0;
 }
@@ -1179,6 +1186,9 @@ static int serial_omap_resume(struct device *dev)
 	if (up) {
 		uart_resume_port(&serial_omap_reg, &up->port);
 		console_unlock();
+
+		if (up->no_async_wake)
+			serial_omap_port_enable(up);
 	}
 
 	return 0;
@@ -1402,6 +1412,7 @@ static int serial_omap_probe(struct platform_device *pdev)
 	up->errata = omap_up_info->errata;
 	up->enable_wakeup = omap_up_info->enable_wakeup;
 	up->chk_wakeup = omap_up_info->chk_wakeup;
+	up->no_async_wake = omap_up_info->no_async_wake;
 
 	if (omap_up_info->dma_enabled) {
 		up->uart_dma.uart_dma_tx = dma_tx->start;
@@ -1430,6 +1441,9 @@ static int serial_omap_probe(struct platform_device *pdev)
 		serial_omap_port_disable(up);
 	}
 
+	if (up->no_async_wake)
+		serial_omap_port_enable(up);
+
 	ui[pdev->id] = up;
 	serial_omap_add_console_port(up);
 
-- 
1.7.1