[PATCH v4 09/11] OMAP2+: Serial: Use prepare and resume calls to gate uart clocks

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

Currently we are using uart prepare and resume calls to gate uart clocks
retaining the same method.

More details on reason to retain this design is provided here:
http://www.spinics.net/lists/linux-serial/msg04128.html

Since prepare and resume hooks are moved to driver itself we can just use
a single prepare and resume call. As in driver we traverse on number of uart
instance and handle it accordingly.

In 34xx uart can wakeup using module level PM_WKEN or IO PAD wakeup use
resume_call from prcm irq handler to wakeup uart, based on chk_wakeup_status
from io_pad or PM_WKST.

Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
---
 arch/arm/mach-omap2/pm24xx.c             |    8 +----
 arch/arm/mach-omap2/pm34xx.c             |   17 +++++-------
 arch/arm/plat-omap/include/plat/serial.h |    4 +-
 drivers/tty/serial/omap-serial.c         |   40 ++++++++++++++++++++++++++++++
 4 files changed, 51 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c
index 39f26af..91eacef 100644
--- a/arch/arm/mach-omap2/pm24xx.c
+++ b/arch/arm/mach-omap2/pm24xx.c
@@ -138,18 +138,14 @@ static void omap2_enter_full_retention(void)
 		if (!console_trylock())
 			goto no_sleep;
 
-	omap_uart_prepare_idle(0);
-	omap_uart_prepare_idle(1);
-	omap_uart_prepare_idle(2);
+	omap_uart_prepare_idle();
 
 	/* Jump to SRAM suspend code */
 	omap2_sram_suspend(sdrc_read_reg(SDRC_DLLA_CTRL),
 			   OMAP_SDRC_REGADDR(SDRC_DLLA_CTRL),
 			   OMAP_SDRC_REGADDR(SDRC_POWER));
 
-	omap_uart_resume_idle(2);
-	omap_uart_resume_idle(1);
-	omap_uart_resume_idle(0);
+	omap_uart_resume_idle();
 
 	if (!is_suspending())
 		console_unlock();
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 9f3bf2c..26ddd56 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -210,6 +210,7 @@ static int prcm_clear_mod_irqs(s16 module, u8 regs)
 
 	wkst = omap2_prm_read_mod_reg(module, wkst_off);
 	wkst &= omap2_prm_read_mod_reg(module, grpsel_off);
+	c += omap_uart_resume_idle();
 	if (wkst) {
 		iclk = omap2_cm_read_mod_reg(module, iclk_off);
 		fclk = omap2_cm_read_mod_reg(module, fclk_off);
@@ -380,17 +381,19 @@ void omap_sram_idle(void)
 	}
 
 	/* Block console output in case it is on one of the OMAP UARTs */
-	if (!is_suspending())
+	if (!is_suspending()) {
 		if (per_next_state < PWRDM_POWER_ON ||
-		    core_next_state < PWRDM_POWER_ON)
+		    core_next_state < PWRDM_POWER_ON) {
 			if (!console_trylock())
 				goto console_still_active;
+			else
+				omap_uart_prepare_idle();
+		}
+	}
 
 	/* PER */
 	if (per_next_state < PWRDM_POWER_ON) {
 		per_going_off = (per_next_state == PWRDM_POWER_OFF) ? 1 : 0;
-		omap_uart_prepare_idle(2);
-		omap_uart_prepare_idle(3);
 		omap2_gpio_prepare_for_idle(per_going_off);
 		if (per_next_state == PWRDM_POWER_OFF)
 				omap3_per_save_context();
@@ -398,8 +401,6 @@ void omap_sram_idle(void)
 
 	/* CORE */
 	if (core_next_state < PWRDM_POWER_ON) {
-		omap_uart_prepare_idle(0);
-		omap_uart_prepare_idle(1);
 		if (core_next_state == PWRDM_POWER_OFF) {
 			omap3_core_save_context();
 			omap3_cm_save_context();
@@ -446,8 +447,6 @@ void omap_sram_idle(void)
 			omap3_sram_restore_context();
 			omap2_sms_restore_context();
 		}
-		omap_uart_resume_idle(0);
-		omap_uart_resume_idle(1);
 		if (core_next_state == PWRDM_POWER_OFF)
 			omap2_prm_clear_mod_reg_bits(OMAP3430_AUTO_OFF_MASK,
 					       OMAP3430_GR_MOD,
@@ -461,8 +460,6 @@ void omap_sram_idle(void)
 		omap2_gpio_resume_after_idle();
 		if (per_prev_state == PWRDM_POWER_OFF)
 			omap3_per_restore_context();
-		omap_uart_resume_idle(2);
-		omap_uart_resume_idle(3);
 	}
 
 	if (!is_suspending())
diff --git a/arch/arm/plat-omap/include/plat/serial.h b/arch/arm/plat-omap/include/plat/serial.h
index bfd73b7..5b8c8f2 100644
--- a/arch/arm/plat-omap/include/plat/serial.h
+++ b/arch/arm/plat-omap/include/plat/serial.h
@@ -109,8 +109,8 @@ struct omap_board_data;
 
 extern void omap_serial_init(void);
 extern void omap_serial_init_port(struct omap_board_data *bdata);
-extern void omap_uart_prepare_idle(int num);
-extern void omap_uart_resume_idle(int num);
+extern void omap_uart_prepare_idle(void);
+extern int omap_uart_resume_idle(void);
 #endif
 
 #endif
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 96fc860..05c2f52 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -54,6 +54,46 @@ static void serial_omap_rx_timeout(unsigned long uart_no);
 static int serial_omap_start_rxdma(struct uart_omap_port *up);
 static void omap_uart_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
 
+int omap_uart_resume_idle()
+{
+	struct uart_omap_port *up;
+	int i, ret = 0;
+
+	for (i = 0; i < OMAP_MAX_HSUART_PORTS; i++) {
+		up = ui[i];
+		if (!up)
+			continue;
+
+		if (!up->clocked && up->chk_wakeup(up->pdev)) {
+			pm_runtime_get_sync(&up->pdev->dev);
+			up->clocked = 1;
+			ret++;
+		}
+	}
+
+	return ret;
+}
+
+void omap_uart_prepare_idle()
+{
+	struct uart_omap_port *up;
+	int i;
+
+	for (i = 0; i < OMAP_MAX_HSUART_PORTS; i++) {
+		up = ui[i];
+		if (!up)
+			continue;
+
+		if (up->clocked &&
+				jiffies_to_msecs(jiffies - up->port_activity)
+					> 3000) {
+			pm_runtime_mark_last_busy(&up->pdev->dev);
+			pm_runtime_put_autosuspend(&up->pdev->dev);
+			up->clocked = 0;
+		}
+	}
+}
+
 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
 {
 	offset <<= up->port.regshift;
-- 
1.7.4.1