samples: move blackfin gptimers-example from Documentation

Move blackfin gptimers-example to samples and remove it from Documentation
Makefile. Update samples Kconfig and Makefile to build gptimers-example.

blackfin is the last CONFIG_BUILD_DOCSRC target in Documentation/Makefile.
Hence this patch also includes changes to remove CONFIG_BUILD_DOCSRC from
Makefile and lib/Kconfig.debug and updates VIDEO_PCI_SKELETON dependency
on BUILD_DOCSRC.

Documentation/Makefile is not deleted to avoid braking make htmldocs and
make distclean.

Acked-by: Michal Marek <mmarek@suse.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reported-by: Valentin Rothberg <valentinrothberg@gmail.com>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

samples/Kconfig

@@ -99,4 +99,10 @@ config SAMPLE_SECCOMP
 	  Build samples of seccomp filters using various methods of
 	  BPF filter construction.
 
+config SAMPLE_BLACKFIN_GPTIMERS
+	tristate "Build blackfin gptimers sample code -- loadable modules only"
+	depends on BLACKFIN && BFIN_GPTIMERS && m
+	help
+	  Build samples of blackfin gptimers sample module.
+
 endif # SAMPLES

samples/Makefile

@@ -2,4 +2,4 @@
 
 obj-$(CONFIG_SAMPLES)	+= kobject/ kprobes/ trace_events/ livepatch/ \
 			   hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
-			   configfs/ connector/ v4l/ trace_printk/
+			   configfs/ connector/ v4l/ trace_printk/ blackfin/

samples/blackfin/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_SAMPLE_BLACKFIN_GPTIMERS) += gptimers-example.o

samples/blackfin/gptimers-example.c

@@ -0,0 +1,91 @@
+/*
+ * Simple gptimers example
+ *	http://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:drivers:gptimers
+ *
+ * Copyright 2007-2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+
+#include <asm/gptimers.h>
+#include <asm/portmux.h>
+
+/* ... random driver includes ... */
+
+#define DRIVER_NAME "gptimer_example"
+
+#ifdef IRQ_TIMER5
+#define SAMPLE_IRQ_TIMER IRQ_TIMER5
+#else
+#define SAMPLE_IRQ_TIMER IRQ_TIMER2
+#endif
+
+struct gptimer_data {
+	uint32_t period, width;
+};
+static struct gptimer_data data;
+
+/* ... random driver state ... */
+
+static irqreturn_t gptimer_example_irq(int irq, void *dev_id)
+{
+	struct gptimer_data *data = dev_id;
+
+	/* make sure it was our timer which caused the interrupt */
+	if (!get_gptimer_intr(TIMER5_id))
+		return IRQ_NONE;
+
+	/* read the width/period values that were captured for the waveform */
+	data->width = get_gptimer_pwidth(TIMER5_id);
+	data->period = get_gptimer_period(TIMER5_id);
+
+	/* acknowledge the interrupt */
+	clear_gptimer_intr(TIMER5_id);
+
+	/* tell the upper layers we took care of things */
+	return IRQ_HANDLED;
+}
+
+/* ... random driver code ... */
+
+static int __init gptimer_example_init(void)
+{
+	int ret;
+
+	/* grab the peripheral pins */
+	ret = peripheral_request(P_TMR5, DRIVER_NAME);
+	if (ret) {
+		printk(KERN_NOTICE DRIVER_NAME ": peripheral request failed\n");
+		return ret;
+	}
+
+	/* grab the IRQ for the timer */
+	ret = request_irq(SAMPLE_IRQ_TIMER, gptimer_example_irq,
+			IRQF_SHARED, DRIVER_NAME, &data);
+	if (ret) {
+		printk(KERN_NOTICE DRIVER_NAME ": IRQ request failed\n");
+		peripheral_free(P_TMR5);
+		return ret;
+	}
+
+	/* setup the timer and enable it */
+	set_gptimer_config(TIMER5_id,
+			WDTH_CAP | PULSE_HI | PERIOD_CNT | IRQ_ENA);
+	enable_gptimers(TIMER5bit);
+
+	return 0;
+}
+module_init(gptimer_example_init);
+
+static void __exit gptimer_example_exit(void)
+{
+	disable_gptimers(TIMER5bit);
+	free_irq(SAMPLE_IRQ_TIMER, &data);
+	peripheral_free(P_TMR5);
+}
+module_exit(gptimer_example_exit);
+
+MODULE_LICENSE("BSD");