dm: omap: gpio: Support driver model

Add driver model support to this driver, while retaining support for the
legacy system. Driver model GPIO support is enabled with CONFIG_DM_GPIO
as usual.

Since gpio_is_valid() no longer exists, we can use the -EINVAL error
returned from gpio_request().

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/drivers/gpio/omap_gpio.c b/drivers/gpio/omap_gpio.c
index d2d2640..a4651bc 100644
--- a/drivers/gpio/omap_gpio.c
+++ b/drivers/gpio/omap_gpio.c
@@ -19,6 +19,7 @@
  * Written by Juha Yrjölä <juha.yrjola@nokia.com>
  */
 #include <common.h>
+#include <dm.h>
 #include <asm/gpio.h>
 #include <asm/io.h>
 #include <asm/errno.h>
@@ -26,6 +27,20 @@
 #define OMAP_GPIO_DIR_OUT	0
 #define OMAP_GPIO_DIR_IN	1
 
+#ifdef CONFIG_DM_GPIO
+
+#define GPIO_NAME_SIZE			20
+#define GPIO_PER_BANK			32
+
+struct gpio_bank {
+	char label[GPIO_PER_BANK][GPIO_NAME_SIZE];
+	/* TODO(sjg@chromium.org): Can we use a struct here? */
+	void *base;	/* address of registers in physical memory */
+	enum gpio_method method;
+};
+
+#endif
+
 static inline int get_gpio_index(int gpio)
 {
 	return gpio & 0x1f;
@@ -130,6 +145,8 @@
 	return (__raw_readl(reg) & (1 << gpio)) != 0;
 }
 
+#ifndef CONFIG_DM_GPIO
+
 static inline const struct gpio_bank *get_gpio_bank(int gpio)
 {
 	return &omap_gpio_bank[gpio >> 5];
@@ -224,5 +241,209 @@
  */
 int gpio_free(unsigned gpio)
 {
+	return 0;
+}
+
+#else /* new driver model interface CONFIG_DM_GPIO */
+
+/**
+ * gpio_is_requested() - check if a GPIO has been requested
+ *
+ * @bank:	Bank to check
+ * @offset:	GPIO offset within bank to check
+ * @return true if marked as requested, false if not
+ */
+static inline bool gpio_is_requested(struct gpio_bank *bank, int offset)
+{
+	return *bank->label[offset] != '\0';
+}
+
+static int omap_gpio_is_output(struct gpio_bank *bank, int offset)
+{
+	return _get_gpio_direction(bank, offset) == OMAP_GPIO_DIR_OUT;
+}
+
+static int check_requested(struct udevice *dev, unsigned offset,
+			   const char *func)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
+	if (!gpio_is_requested(bank, offset)) {
+		printf("omap_gpio: %s: error: gpio %s%d not requested\n",
+		       func, uc_priv->bank_name, offset);
+		return -EPERM;
+	}
+
+	return 0;
+}
+
+/* set GPIO pin 'gpio' as an input */
+static int omap_gpio_direction_input(struct udevice *dev, unsigned offset)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+
+	/* Configure GPIO direction as input. */
+	_set_gpio_direction(bank, offset, 1);
+
+	return 0;
+}
+
+/* set GPIO pin 'gpio' as an output, with polarity 'value' */
+static int omap_gpio_direction_output(struct udevice *dev, unsigned offset,
+				       int value)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+
+	_set_gpio_dataout(bank, offset, value);
+	_set_gpio_direction(bank, offset, 0);
+
+	return 0;
+}
+
+/* read GPIO IN value of pin 'gpio' */
+static int omap_gpio_get_value(struct udevice *dev, unsigned offset)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+
+	return _get_gpio_value(bank, offset);
+}
+
+/* write GPIO OUT value to pin 'gpio' */
+static int omap_gpio_set_value(struct udevice *dev, unsigned offset,
+				 int value)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+
+	_set_gpio_dataout(bank, offset, value);
+
 	return 0;
 }
+
+static int omap_gpio_get_state(struct udevice *dev, unsigned int offset,
+			      char *buf, int bufsize)
+{
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+	struct gpio_bank *bank = dev_get_priv(dev);
+	const char *label;
+	bool requested;
+	bool is_output;
+	int size;
+
+	label = bank->label[offset];
+	is_output = omap_gpio_is_output(bank->base, offset);
+	size = snprintf(buf, bufsize, "%s%d: ",
+			uc_priv->bank_name ? uc_priv->bank_name : "", offset);
+	buf += size;
+	bufsize -= size;
+	requested = gpio_is_requested(bank, offset);
+	snprintf(buf, bufsize, "%s: %d [%c]%s%s",
+		 is_output ? "out" : " in",
+		 _get_gpio_value(bank, offset),
+		 requested ? 'x' : ' ',
+		 requested ? " " : "",
+		 label);
+
+	return 0;
+}
+
+static int omap_gpio_request(struct udevice *dev, unsigned offset,
+			      const char *label)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+
+	if (gpio_is_requested(bank, offset))
+		return -EBUSY;
+
+	strncpy(bank->label[offset], label, GPIO_NAME_SIZE);
+	bank->label[offset][GPIO_NAME_SIZE - 1] = '\0';
+
+	return 0;
+}
+
+static int omap_gpio_free(struct udevice *dev, unsigned offset)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+	bank->label[offset][0] = '\0';
+
+	return 0;
+}
+
+static int omap_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+
+	if (!gpio_is_requested(bank, offset))
+		return GPIOF_UNUSED;
+
+	/* GPIOF_FUNC is not implemented yet */
+	if (_get_gpio_direction(bank->base, offset))
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static const struct dm_gpio_ops gpio_omap_ops = {
+	.request		= omap_gpio_request,
+	.free			= omap_gpio_free,
+	.direction_input	= omap_gpio_direction_input,
+	.direction_output	= omap_gpio_direction_output,
+	.get_value		= omap_gpio_get_value,
+	.set_value		= omap_gpio_set_value,
+	.get_function		= omap_gpio_get_function,
+	.get_state		= omap_gpio_get_state,
+};
+
+static int omap_gpio_probe(struct udevice *dev)
+{
+	struct gpio_bank *bank = dev_get_priv(dev);
+	struct omap_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+	char name[18], *str;
+
+	sprintf(name, "GPIO%d_", plat->bank_index);
+	str = strdup(name);
+	if (!str)
+		return -ENOMEM;
+	uc_priv->bank_name = str;
+	uc_priv->gpio_count = GPIO_PER_BANK;
+	bank->base = (void *)plat->base;
+	bank->method = plat->method;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(gpio_omap) = {
+	.name	= "gpio_omap",
+	.id	= UCLASS_GPIO,
+	.ops	= &gpio_omap_ops,
+	.probe	= omap_gpio_probe,
+	.priv_auto_alloc_size = sizeof(struct gpio_bank),
+};
+
+#endif /* CONFIG_DM_GPIO */