MFD: ucb1x00: convert to use genirq

Convert the ucb1x00 driver to use genirq's interrupt services, rather
than its own private implementation.  This allows a wider range of
drivers to use the GPIO interrupts (such as the gpio_keys driver)
without being aware of the UCB1x00's private IRQ system.

This prevents the UCB1x00 core driver from being built as a module,
so adjust the configuration to add that restriction.
Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/mfd/Kconfig

@@ -847,8 +847,9 @@ config MCP_SA11X0
 
 # Chip drivers
 config MCP_UCB1200
-	tristate "Support for UCB1200 / UCB1300"
-	depends on MCP
+	bool "Support for UCB1200 / UCB1300"
+	depends on MCP_SA11X0
+	select MCP
 
 config MCP_UCB1200_TS
 	tristate "Touchscreen interface support"

drivers/mfd/ucb1x00-ts.c

@@ -20,8 +20,9 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
-#include <linux/smp.h>
+#include <linux/interrupt.h>
 #include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/string.h>
@@ -41,6 +42,8 @@ struct ucb1x00_ts {
 	struct input_dev	*idev;
 	struct ucb1x00		*ucb;
 
+	spinlock_t		irq_lock;
+	unsigned		irq_disabled;
 	wait_queue_head_t	irq_wait;
 	struct task_struct	*rtask;
 	u16			x_res;
@@ -237,7 +240,12 @@ static int ucb1x00_thread(void *_ts)
 		if (ucb1x00_ts_pen_down(ts)) {
 			set_current_state(TASK_INTERRUPTIBLE);
 
-			ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
+			spin_lock_irq(&ts->irq_lock);
+			if (ts->irq_disabled) {
+				ts->irq_disabled = 0;
+				enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
+			}
+			spin_unlock_irq(&ts->irq_lock);
 			ucb1x00_disable(ts->ucb);
 
 			/*
@@ -280,23 +288,37 @@ static int ucb1x00_thread(void *_ts)
  * We only detect touch screen _touches_ with this interrupt
  * handler, and even then we just schedule our task.
  */
-static void ucb1x00_ts_irq(int idx, void *id)
+static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
 {
 	struct ucb1x00_ts *ts = id;
 
-	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+	spin_lock(&ts->irq_lock);
+	ts->irq_disabled = 1;
+	disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
+	spin_unlock(&ts->irq_lock);
 	wake_up(&ts->irq_wait);
+
+	return IRQ_HANDLED;
 }
 
 static int ucb1x00_ts_open(struct input_dev *idev)
 {
 	struct ucb1x00_ts *ts = input_get_drvdata(idev);
+	unsigned long flags = 0;
 	int ret = 0;
 
 	BUG_ON(ts->rtask);
 
+	if (machine_is_collie())
+		flags = IRQF_TRIGGER_RISING;
+	else
+		flags = IRQF_TRIGGER_FALLING;
+
+	ts->irq_disabled = 0;
+
 	init_waitqueue_head(&ts->irq_wait);
-	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
+	ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
+			  flags, "ucb1x00-ts", ts);
 	if (ret < 0)
 		goto out;
 
@@ -313,7 +335,7 @@ static int ucb1x00_ts_open(struct input_dev *idev)
 	if (!IS_ERR(ts->rtask)) {
 		ret = 0;
 	} else {
-		ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+		free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
 		ts->rtask = NULL;
 		ret = -EFAULT;
 	}
@@ -333,7 +355,7 @@ static void ucb1x00_ts_close(struct input_dev *idev)
 		kthread_stop(ts->rtask);
 
 	ucb1x00_enable(ts->ucb);
-	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
 	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
 	ucb1x00_disable(ts->ucb);
 }
@@ -358,6 +380,7 @@ static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
 	ts->ucb = dev->ucb;
 	ts->idev = idev;
 	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
+	spin_lock_init(&ts->irq_lock);
 
 	idev->name       = "Touchscreen panel";
 	idev->id.product = ts->ucb->id;

include/linux/mfd/ucb1x00.h

@@ -112,18 +112,15 @@ enum ucb1x00_reset {
 
 struct ucb1x00_plat_data {
 	void			(*reset)(enum ucb1x00_reset);
+	unsigned		irq_base;
 	int			gpio_base;
 };
 
-struct ucb1x00_irq {
-	void *devid;
-	void (*fn)(int, void *);
-};
-
 struct ucb1x00 {
-	spinlock_t		lock;
+	raw_spinlock_t		irq_lock;
 	struct mcp		*mcp;
 	unsigned int		irq;
+	int			irq_base;
 	struct mutex		adc_mutex;
 	spinlock_t		io_lock;
 	u16			id;
@@ -132,7 +129,7 @@ struct ucb1x00 {
 	u16			adc_cr;
 	u16			irq_fal_enbl;
 	u16			irq_ris_enbl;
-	struct ucb1x00_irq	irq_handler[16];
+	u16			irq_mask;
 	struct device		dev;
 	struct list_head	node;
 	struct list_head	devs;
@@ -255,15 +252,4 @@ unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync);
 void ucb1x00_adc_enable(struct ucb1x00 *ucb);
 void ucb1x00_adc_disable(struct ucb1x00 *ucb);
 
-/*
- * Which edges of the IRQ do you want to control today?
- */
-#define UCB_RISING	(1 << 0)
-#define UCB_FALLING	(1 << 1)
-
-int ucb1x00_hook_irq(struct ucb1x00 *ucb, unsigned int idx, void (*fn)(int, void *), void *devid);
-void ucb1x00_enable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges);
-void ucb1x00_disable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges);
-int ucb1x00_free_irq(struct ucb1x00 *ucb, unsigned int idx, void *devid);
-
 #endif