dm: demo: Add a simple GPIO demonstration
Add a new 'demo light' command which uses GPIOs to control imaginary lights.
Each light is assigned a bit number in the overall value. This provides an
example driver for using the new GPIO API.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/demo/demo-shape.c b/drivers/demo/demo-shape.c
index 3fa9c59..d908736 100644
--- a/drivers/demo/demo-shape.c
+++ b/drivers/demo/demo-shape.c
@@ -11,6 +11,7 @@
#include <malloc.h>
#include <dm-demo.h>
#include <asm/io.h>
+#include <asm/gpio.h>
DECLARE_GLOBAL_DATA_PTR;
@@ -20,6 +21,8 @@
struct shape_data {
int num_chars; /* Number of non-space characters output so far */
+ struct gpio_desc gpio_desc[8];
+ int gpio_count;
};
/* Crazy little function to draw shapes on the console */
@@ -89,9 +92,52 @@
return 0;
}
+static int set_light(struct udevice *dev, int light)
+{
+ struct shape_data *priv = dev_get_priv(dev);
+ struct gpio_desc *desc;
+ int ret;
+ int i;
+
+ desc = priv->gpio_desc;
+ for (i = 0; i < priv->gpio_count; i++, desc++) {
+ uint mask = 1 << i;
+
+ ret = dm_gpio_set_value(desc, light & mask);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int get_light(struct udevice *dev)
+{
+ struct shape_data *priv = dev_get_priv(dev);
+ struct gpio_desc *desc;
+ uint value = 0;
+ int ret;
+ int i;
+
+ desc = priv->gpio_desc;
+ for (i = 0; i < priv->gpio_count; i++, desc++) {
+ uint mask = 1 << i;
+
+ ret = dm_gpio_get_value(desc);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ value |= mask;
+ }
+
+ return value;
+}
+
static const struct demo_ops shape_ops = {
.hello = shape_hello,
.status = shape_status,
+ .get_light = get_light,
+ .set_light = set_light,
};
static int shape_ofdata_to_platdata(struct udevice *dev)
@@ -111,6 +157,29 @@
return 0;
}
+static int dm_shape_probe(struct udevice *dev)
+{
+ struct shape_data *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = gpio_request_list_by_name(dev, "light-gpios", priv->gpio_desc,
+ ARRAY_SIZE(priv->gpio_desc),
+ GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+ if (ret < 0)
+ return ret;
+ priv->gpio_count = ret;
+ debug("%s: %d GPIOs\n", __func__, priv->gpio_count);
+
+ return 0;
+}
+
+static int dm_shape_remove(struct udevice *dev)
+{
+ struct shape_data *priv = dev_get_priv(dev);
+
+ return gpio_free_list(dev, priv->gpio_desc, priv->gpio_count);
+}
+
static const struct udevice_id demo_shape_id[] = {
{ "demo-shape", 0 },
{ },
@@ -122,6 +191,8 @@
.id = UCLASS_DEMO,
.ofdata_to_platdata = shape_ofdata_to_platdata,
.ops = &shape_ops,
+ .probe = dm_shape_probe,
+ .remove = dm_shape_remove,
.priv_auto_alloc_size = sizeof(struct shape_data),
.platdata_auto_alloc_size = sizeof(struct dm_demo_pdata),
};