add drivers/mfd/twl4030-core.c

From: David Brownell <[email protected]>

This patch adds the core of the TWL4030 driver, which supports chips including the TPS65950. These chips are multi-function; see

http://focus.ti.com/docs/prod/folders/print/tps65950.html

Public specs are in the works. For now, the block diagram on the second page of the datasheet is fairly informative.

There are some known issues with this core code. Most notably, the IRQ dispatching needs simplification (to use more of genirq), generalization (integrating support for secondary IRQ dispatch as well as primary, and removing the build dependency on OMAP), and then probably updating to leverage threaded IRQ support (expected to arrive in mainline "soon").

Once the core is in mainline, drivers for other parts of this chip can follow its lead and start swimming upstream too.

Signed-off-by David Brownell <[email protected]>

Thanks, applied to my mfd tree.

Quoted 2 lines

+#if defined(CONFIG_TWL4030_BCI_BATTERY) || \
+     defined(CONFIG_TWL4030_BCI_BATTERY_MODUEL)

minor typo, you probably meant: CONFIG_TWL4030_BCI_BATTERY_MODULE

Quoted 1 line · Samuel Ortiz

Thanks, applied to my mfd tree.

Great!

Quoted 4 lines

Quoted 2 lines

+#if defined(CONFIG_TWL4030_BCI_BATTERY) || \
+     defined(CONFIG_TWL4030_BCI_BATTERY_MODUEL)

minor typo, you probably meant: CONFIG_TWL4030_BCI_BATTERY_MODULE

Yes, good catch. You'll tweak?

Appended is that simple IRQ cleanup I mentioned.
(Get a load of the diffstat!)

There's more substantial IRQ stuff on the way, but it won't be ready before the 2.6.28 merges start.

- Dave

================== CUT HERE
From: David Brownell <[email protected]>

twl4030-core irq simplification

Simplify twl4030 IRQ handling by removing a needless custom flow handler. The top level IRQs, from the PIH, are well suited for handle_simple_irq() ... they can't be acked or masked.

Switching resolves some issues with how IRQs were dispatched. Notably, abuse of desc->status, IRQ accounting, and handling of various faults.

In short, use standard genirq code.

Drivers that request_irq() to the PIH will need to pay more attention to things like setting IRQF_DISABLED (since it's no longer ignored), and making I2C calls from handlers (you'll need a lockdep workaround).

Signed-off-by David Brownell <[email protected]>

Signed-off-by Tony Lindgren <[email protected]>

---
 drivers/mfd/twl4030-core.c |   68 +--------------------------------------------
 1 file changed, 2 insertions(+), 66 deletions(-)

drivers/mfd/twl4030-core.c +2 -66

@@ -535,68 +535,6 @@ EXPORT_SYMBOL(twl4030_i2c_read_u8);
 
 /*----------------------------------------------------------------------*/
 
-/*
- * do_twl4030_module_irq() is the desc->handle method for each of the twl4030
- * module interrupts that doesn't chain to another irq_chip (GPIO, power, etc).
- * It executes in kernel thread context.  On entry, cpu interrupts are disabled.
- */
-static void do_twl4030_module_irq(unsigned int irq, irq_desc_t *desc)
-{
-	struct irqaction *action;
-	const unsigned int cpu = smp_processor_id();
-
-	/*
-	 * Earlier this was desc->triggered = 1;
-	 */
-	desc->status |= IRQ_LEVEL;
-
-	/*
-	 * The desc->handle method would normally call the desc->chip->ack
-	 * method here, but we won't bother since our ack method is NULL.
-	 */
-
-	if (!desc->depth) {
-		kstat_cpu(cpu).irqs[irq]++;
-
-		action = desc->action;
-		if (action) {
-			int ret;
-			int status = 0;
-			int retval = 0;
-
-			local_irq_enable();
-
-			do {
-				/* Call the ISR with cpu interrupts enabled */
-				ret = action->handler(irq, action->dev_id);
-				if (ret == IRQ_HANDLED)
-					status |= action->flags;
-				retval |= ret;
-				action = action->next;
-			} while (action);
-
-			if (status & IRQF_SAMPLE_RANDOM)
-				add_interrupt_randomness(irq);
-
-			local_irq_disable();
-
-			if (retval != IRQ_HANDLED)
-				printk(KERN_ERR "ISR for TWL4030 module"
-					" irq %d can't handle interrupt\n",
-					irq);
-
-			/*
-			 * Here is where we should call the unmask method, but
-			 * again we won't bother since it is NULL.
-			 */
-		} else
-			printk(KERN_CRIT "TWL4030 module irq %d has no ISR"
-					" but can't be masked!\n", irq);
-	} else
-		printk(KERN_CRIT "TWL4030 module irq %d is disabled but can't"
-				" be masked!\n", irq);
-}
-
 static unsigned twl4030_irq_base;
 
 static struct completion irq_event;

@@ -611,7 +549,6 @@ static int twl4030_irq_thread(void *data)
 	static unsigned i2c_errors;
 	const static unsigned max_i2c_errors = 100;
 
-	daemonize("twl4030-irq");
 	current->flags |= PF_NOFREEZE;
 
 	while (!kthread_should_stop()) {

@@ -691,8 +628,7 @@ static struct task_struct * __init start_twl4030_irq_thread(long irq)
 	struct task_struct *thread;
 
 	init_completion(&irq_event);
-	thread = kthread_run(twl4030_irq_thread, (void *)irq,
-			     "twl4030 irq %ld", irq);
+	thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq");
 	if (!thread)
 		pr_err("%s: could not create twl4030 irq %ld thread!\n",
 		       DRIVER_NAME, irq);

@@ -1126,7 +1062,7 @@ static void twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
 	/* install an irq handler for each of the PIH modules */
 	for (i = irq_base; i < irq_end; i++) {
 		set_irq_chip_and_handler(i, &twl4030_irq_chip,
-				do_twl4030_module_irq);
+				handle_simple_irq);
 		activate_irq(i);
 	}
 

Quoted 2 lines

There's more substantial IRQ stuff on the way, but it won't be ready before the 2.6.28 merges start.

I can still take patches during the merge window, if you think they're really ready and necessary.

This patch adds the core of the TWL4030 driver, which supports chips including the TPS65950.  These chips are multi-function; see

  http://focus.ti.com/docs/prod/folders/print/tps65950.html

Public specs are in the works.