dm: rpi: Convert GPIO driver to driver model

Convert the BCM2835 GPIO driver to use driver model, and switch over
Raspberry Pi to use this, since it is the only board.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>

arch/arm/include/asm/arch-bcm2835/gpio.h

@@ -52,4 +52,13 @@ struct bcm2835_gpio_regs {
 	u32 gppudclk[2];
 };
 
+/**
+ * struct bcm2835_gpio_platdata - GPIO platform description
+ *
+ * @base: Base address of GPIO controller
+ */
+struct bcm2835_gpio_platdata {
+	unsigned long base;
+};
+
 #endif /* _BCM2835_GPIO_H_ */

board/raspberrypi/rpi_b/rpi_b.c

@@ -16,15 +16,26 @@
 
 #include <common.h>
 #include <config.h>
+#include <dm.h>
 #include <fdt_support.h>
 #include <lcd.h>
 #include <mmc.h>
+#include <asm/gpio.h>
 #include <asm/arch/mbox.h>
 #include <asm/arch/sdhci.h>
 #include <asm/global_data.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static const struct bcm2835_gpio_platdata gpio_platdata = {
+	.base = BCM2835_GPIO_BASE,
+};
+
+U_BOOT_DEVICE(bcm2835_gpios) = {
+	.name = "gpio_bcm2835",
+	.platdata = &gpio_platdata,
+};
+
 struct msg_get_arm_mem {
 	struct bcm2835_mbox_hdr hdr;
 	struct bcm2835_mbox_tag_get_arm_mem get_arm_mem;

drivers/gpio/bcm2835_gpio.c

@@ -6,73 +6,207 @@
  */
 
 #include <common.h>
+#include <dm.h>
+#include <errno.h>
 #include <asm/gpio.h>
 #include <asm/io.h>
 
-inline int gpio_is_valid(unsigned gpio)
+#define GPIO_NAME_SIZE		20
+
+struct bcm2835_gpios {
+	char label[BCM2835_GPIO_COUNT][GPIO_NAME_SIZE];
+	struct bcm2835_gpio_regs *reg;
+};
+
+/**
+ * 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 bcm2835_gpios *gpios, int offset)
 {
-	return (gpio < BCM2835_GPIO_COUNT);
+	return *gpios->label[offset] != '\0';
 }
 
-int gpio_request(unsigned gpio, const char *label)
+static int check_requested(struct udevice *dev, unsigned offset,
+			   const char *func)
 {
-	return !gpio_is_valid(gpio);
-}
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
+	if (!gpio_is_requested(gpios, offset)) {
+		printf("omap_gpio: %s: error: gpio %s%d not requested\n",
+		       func, uc_priv->bank_name, offset);
+		return -EPERM;
+	}
 
-int gpio_free(unsigned gpio)
-{
 	return 0;
 }
 
-int gpio_direction_input(unsigned gpio)
+static int bcm2835_gpio_request(struct udevice *dev, unsigned offset,
+				const char *label)
 {
-	struct bcm2835_gpio_regs *reg =
-		(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+
+	if (gpio_is_requested(gpios, offset))
+		return -EBUSY;
+
+	strncpy(gpios->label[offset], label, GPIO_NAME_SIZE);
+	gpios->label[offset][GPIO_NAME_SIZE - 1] = '\0';
+
+	return 0;
+}
+
+static int bcm2835_gpio_free(struct udevice *dev, unsigned offset)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	int ret;
+
+	ret = check_requested(dev, offset, __func__);
+	if (ret)
+		return ret;
+	gpios->label[offset][0] = '\0';
+
+	return 0;
+}
+
+static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
 	unsigned val;
 
-	val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
 	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
 	val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
-	writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
 
 	return 0;
 }
 
-int gpio_direction_output(unsigned gpio, int value)
+static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned gpio,
+					 int value)
 {
-	struct bcm2835_gpio_regs *reg =
-		(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
 	unsigned val;
 
 	gpio_set_value(gpio, value);
 
-	val = readl(&reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
 	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
 	val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
-	writel(val, &reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
 
 	return 0;
 }
 
-int gpio_get_value(unsigned gpio)
+static bool bcm2835_gpio_is_output(const struct bcm2835_gpios *gpios, int gpio)
+{
+	u32 val;
+
+	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	val &= BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio);
+	return val ? true : false;
+}
+
+static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
 {
-	struct bcm2835_gpio_regs *reg =
-		(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
 	unsigned val;
 
-	val = readl(&reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
+	val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
 
 	return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
 }
 
-int gpio_set_value(unsigned gpio, int value)
+static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
 {
-	struct bcm2835_gpio_regs *reg =
-		(struct bcm2835_gpio_regs *)BCM2835_GPIO_BASE;
-	u32 *output_reg = value ? reg->gpset : reg->gpclr;
+	const struct bcm2835_gpios *gpios = dev_get_priv(dev);
+
+	return bcm2835_get_value(gpios, gpio);
+}
+
+static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
+				  int value)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
 
 	writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
 				&output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
 
 	return 0;
 }
+
+static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+
+	if (!gpio_is_requested(gpios, offset))
+		return GPIOF_UNUSED;
+
+	/* GPIOF_FUNC is not implemented yet */
+	if (bcm2835_gpio_is_output(gpios, offset))
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static int bcm2835_gpio_get_state(struct udevice *dev, unsigned int offset,
+				  char *buf, int bufsize)
+{
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	const char *label;
+	bool requested;
+	bool is_output;
+	int size;
+
+	label = gpios->label[offset];
+	is_output = bcm2835_gpio_is_output(gpios, offset);
+	size = snprintf(buf, bufsize, "%s%d: ",
+			uc_priv->bank_name ? uc_priv->bank_name : "", offset);
+	buf += size;
+	bufsize -= size;
+	requested = gpio_is_requested(gpios, offset);
+	snprintf(buf, bufsize, "%s: %d [%c]%s%s",
+		 is_output ? "out" : " in",
+		 bcm2835_get_value(gpios, offset),
+		 requested ? 'x' : ' ',
+		 requested ? " " : "",
+		 label);
+
+	return 0;
+}
+
+static const struct dm_gpio_ops gpio_bcm2835_ops = {
+	.request		= bcm2835_gpio_request,
+	.free			= bcm2835_gpio_free,
+	.direction_input	= bcm2835_gpio_direction_input,
+	.direction_output	= bcm2835_gpio_direction_output,
+	.get_value		= bcm2835_gpio_get_value,
+	.set_value		= bcm2835_gpio_set_value,
+	.get_function		= bcm2835_gpio_get_function,
+	.get_state		= bcm2835_gpio_get_state,
+};
+
+static int bcm2835_gpio_probe(struct udevice *dev)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+
+	uc_priv->bank_name = "GPIO";
+	uc_priv->gpio_count = BCM2835_GPIO_COUNT;
+	gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
+
+	return 0;
+}
+
+U_BOOT_DRIVER(gpio_bcm2835) = {
+	.name	= "gpio_bcm2835",
+	.id	= UCLASS_GPIO,
+	.ops	= &gpio_bcm2835_ops,
+	.probe	= bcm2835_gpio_probe,
+	.priv_auto_alloc_size = sizeof(struct bcm2835_gpios),
+};

include/configs/rpi_b.h

@@ -31,6 +31,11 @@
  */
 #define CONFIG_MACH_TYPE		MACH_TYPE_BCM2708
 
+/* Enable driver model */
+#define CONFIG_DM
+#define CONFIG_CMD_DM
+#define CONFIG_DM_GPIO
+
 /* Memory layout */
 #define CONFIG_NR_DRAM_BANKS		1
 #define CONFIG_SYS_SDRAM_BASE		0x00000000