power: Add a GPIO driver for the as3722 PMIC

This pmic includes GPIOs which should have their own driver. Add
a driver to support these.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-on: Beaver, Jetson-TK1
Tested-by: Stephen Warren <swarren@nvidia.com>

drivers/power/pmic/as3722_gpio.c

@@ -0,0 +1,120 @@
+/*
+ * Copyright (C) 2014 NVIDIA Corporation
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/gpio.h>
+#include <power/as3722.h>
+#include <power/pmic.h>
+
+#define NUM_GPIOS	8
+
+int as3722_gpio_configure(struct udevice *pmic, unsigned int gpio,
+			  unsigned long flags)
+{
+	u8 value = 0;
+	int err;
+
+	if (flags & AS3722_GPIO_OUTPUT_VDDH)
+		value |= AS3722_GPIO_CONTROL_MODE_OUTPUT_VDDH;
+
+	if (flags & AS3722_GPIO_INVERT)
+		value |= AS3722_GPIO_CONTROL_INVERT;
+
+	err = pmic_reg_write(pmic, AS3722_GPIO_CONTROL(gpio), value);
+	if (err) {
+		error("failed to configure GPIO#%u: %d", gpio, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int as3722_gpio_set_value(struct udevice *dev, unsigned int gpio,
+				 int level)
+{
+	struct udevice *pmic = dev_get_parent(dev);
+	const char *l;
+	u8 value;
+	int err;
+
+	if (gpio >= NUM_GPIOS)
+		return -EINVAL;
+
+	err = pmic_reg_read(pmic, AS3722_GPIO_SIGNAL_OUT);
+	if (err < 0) {
+		error("failed to read GPIO signal out register: %d", err);
+		return err;
+	}
+	value = err;
+
+	if (level == 0) {
+		value &= ~(1 << gpio);
+		l = "low";
+	} else {
+		value |= 1 << gpio;
+		l = "high";
+	}
+
+	err = pmic_reg_write(pmic, AS3722_GPIO_SIGNAL_OUT, value);
+	if (err) {
+		error("failed to set GPIO#%u %s: %d", gpio, l, err);
+		return err;
+	}
+
+	return 0;
+}
+
+int as3722_gpio_direction_output(struct udevice *dev, unsigned int gpio,
+				 int value)
+{
+	struct udevice *pmic = dev_get_parent(dev);
+	int err;
+
+	if (gpio > 7)
+		return -EINVAL;
+
+	if (value == 0)
+		value = AS3722_GPIO_CONTROL_MODE_OUTPUT_VDDL;
+	else
+		value = AS3722_GPIO_CONTROL_MODE_OUTPUT_VDDH;
+
+	err = pmic_reg_write(pmic, AS3722_GPIO_CONTROL(gpio), value);
+	if (err) {
+		error("failed to configure GPIO#%u as output: %d", gpio, err);
+		return err;
+	}
+
+	err = as3722_gpio_set_value(pmic, gpio, value);
+	if (err < 0) {
+		error("failed to set GPIO#%u high: %d", gpio, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int as3722_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+
+	uc_priv->gpio_count = NUM_GPIOS;
+	uc_priv->bank_name = "as3722_";
+
+	return 0;
+}
+
+static const struct dm_gpio_ops gpio_as3722_ops = {
+	.direction_output	= as3722_gpio_direction_output,
+	.set_value		= as3722_gpio_set_value,
+};
+
+U_BOOT_DRIVER(gpio_as3722) = {
+	.name	= "gpio_as3722",
+	.id	= UCLASS_GPIO,
+	.ops	= &gpio_as3722_ops,
+	.probe	= as3722_gpio_probe,
+};

include/power/as3722.h

@@ -20,6 +20,11 @@
 #define AS3722_ASIC_ID1 0x90
 #define AS3722_ASIC_ID2 0x91
 
+#define AS3722_GPIO_CONTROL(n) (0x08 + (n))
+#define AS3722_GPIO_CONTROL_MODE_OUTPUT_VDDH (1 << 0)
+#define AS3722_GPIO_CONTROL_MODE_OUTPUT_VDDL (7 << 0)
+#define AS3722_GPIO_CONTROL_INVERT (1 << 7)
+
 struct udevice;
 
 int as3722_init(struct udevice **devp);