Blackfin: add an example showing how to use the gptimers API
Mike Frysinger [Wed, 21 Oct 2009 21:22:35 +0000 (21:22 +0000)]
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

Documentation/blackfin/Makefile [new file with mode: 0644]
Documentation/blackfin/gptimers-example.c [new file with mode: 0644]

diff --git a/Documentation/blackfin/Makefile b/Documentation/blackfin/Makefile
new file mode 100644 (file)
index 0000000..773dbb1
--- /dev/null
@@ -0,0 +1,6 @@
+obj-m := gptimers-example.o
+
+all: modules
+
+modules clean:
+       $(MAKE) -C ../.. SUBDIRS=$(PWD) $@
diff --git a/Documentation/blackfin/gptimers-example.c b/Documentation/blackfin/gptimers-example.c
new file mode 100644 (file)
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@@ -0,0 +1,83 @@
+/*
+ * 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"
+
+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(IRQ_TIMER5, 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(IRQ_TIMER5, &data);
+       peripheral_free(P_TMR5);
+}
+module_exit(gptimer_example_exit);
+
+MODULE_LICENSE("BSD");