[RFC/NOT FOR MERGING 2/3] serial: omap: remove hwmod dependency

[Felipe Balbi <balbi@ti.com>]

Currently the omap-serial driver will not
work properly if booted via DT with CPUIDLE
enabled because it depends on function pointers
provided by hwmod to change its own SYSCONFIG
register.

Remove that relyance on hwmod by moving SYSCONFIG
handling to driver itself. Note that this also
fixes a possible corner case bug where we could
be putting UART in Force Idle mode if we called
omap_serial_enable_wakeup(up, false) after setting
NOIDLE to the idle mode. This is because hwmod
has no protection against that situation.

NYET-Signed-off-by: Felipe Balbi <balbi@ti.com>
---
 drivers/tty/serial/omap-serial.c | 67 +++++++++++++++++++---------------------
 1 file changed, 32 insertions(+), 35 deletions(-)

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 57d6b29..078beb1 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -96,6 +96,18 @@
 
 #define OMAP_UART_TCR_TRIG	0x0F
 
+#define OMAP_UART_SYSC		0x54
+#define OMAP_UART_AUTOIDLE	(1 << 0)
+#define OMAP_UART_SOFTRESET	(1 << 1)
+#define OMAP_UART_ENAWAKEUP	(1 << 2)
+
+#define OMAP_UART_IDLEMODE(n)	(((n) & 3) << 3)
+#define OMAP_UART_FORCE_IDLE	OMAP_UART_IDLEMODE(0)
+#define OMAP_UART_NO_IDLE	OMAP_UART_IDLEMODE(1)
+#define OMAP_UART_SMART_IDLE	OMAP_UART_IDLEMODE(2)
+#define OMAP_UART_SMART_IDLE_WKUP OMAP_UART_IDLEMODE(3)
+#define OMAP_UART_IDLEMODE_MASK	OMAP_UART_SMART_IDLE_WKUP
+
 struct uart_omap_dma {
 	u8			uart_dma_tx;
 	u8			uart_dma_rx;
@@ -191,44 +203,39 @@ static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
 	serial_out(up, UART_FCR, 0);
 }
 
-static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
-{
-	struct omap_uart_port_info *pdata = up->dev->platform_data;
-
-	if (!pdata || !pdata->get_context_loss_count)
-		return 0;
-
-	return pdata->get_context_loss_count(up->dev);
-}
-
 static void serial_omap_set_forceidle(struct uart_omap_port *up)
 {
-	struct omap_uart_port_info *pdata = up->dev->platform_data;
-
-	if (!pdata || !pdata->set_forceidle)
-		return;
+	u32 reg;
 
-	pdata->set_forceidle(up->dev);
+	reg = serial_in(up, OMAP_UART_SYSC);
+	reg &= ~OMAP_UART_IDLEMODE_MASK;
+	reg |= OMAP_UART_FORCE_IDLE;
+	serial_out(up, OMAP_UART_SYSC, reg);
 }
 
 static void serial_omap_set_noidle(struct uart_omap_port *up)
 {
-	struct omap_uart_port_info *pdata = up->dev->platform_data;
+	u32 reg;
 
-	if (!pdata || !pdata->set_noidle)
-		return;
-
-	pdata->set_noidle(up->dev);
+	reg = serial_in(up, OMAP_UART_SYSC);
+	reg &= ~OMAP_UART_IDLEMODE_MASK;
+	reg |= OMAP_UART_NO_IDLE;
+	serial_out(up, OMAP_UART_SYSC, reg);
 }
 
 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
 {
-	struct omap_uart_port_info *pdata = up->dev->platform_data;
+	u32 reg;
 
-	if (!pdata || !pdata->enable_wakeup)
-		return;
+	reg = serial_in(up, OMAP_UART_SYSC);
+	reg &= ~OMAP_UART_IDLEMODE_MASK;
+
+	if (enable)
+		reg |= OMAP_UART_SMART_IDLE_WKUP;
+	else
+		reg |= OMAP_UART_SMART_IDLE;
 
-	pdata->enable_wakeup(up->dev, enable);
+	serial_out(up, OMAP_UART_SYSC, reg);
 }
 
 /*
@@ -1596,8 +1603,6 @@ static int serial_omap_runtime_suspend(struct device *dev)
 	if (!pdata)
 		return 0;
 
-	up->context_loss_cnt = serial_omap_get_context_loss_count(up);
-
 	if (device_may_wakeup(dev)) {
 		if (!up->wakeups_enabled) {
 			serial_omap_enable_wakeup(up, true);
@@ -1620,15 +1625,7 @@ static int serial_omap_runtime_resume(struct device *dev)
 {
 	struct uart_omap_port *up = dev_get_drvdata(dev);
 
-	int loss_cnt = serial_omap_get_context_loss_count(up);
-
-	if (loss_cnt < 0) {
-		dev_err(dev, "serial_omap_get_context_loss_count failed : %d\n",
-			loss_cnt);
-		serial_omap_restore_context(up);
-	} else if (up->context_loss_cnt != loss_cnt) {
-		serial_omap_restore_context(up);
-	}
+	serial_omap_restore_context(up);
 	up->latency = up->calc_latency;
 	schedule_work(&up->qos_work);
 
-- 
1.8.1.rc1.5.g7e0651a