zynqmp: gpio: Add support for zynqmp gpio modepin driver

ZynqMP modepin driver has capability to get/set/check status of modepin
gpios. These modepins are accessed using xilinx firmware. In modepin
register, [3:0] bits set direction, [7:4] bits read IO, [11:8] bits
set/clear IO.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/2d802d98fd56d95d764532a33e844d935e0cebb3.1635505900.git.michal.simek@xilinx.com

MAINTAINERS

@@ -602,6 +602,7 @@ F:	drivers/clk/clk_zynqmp.c
 F:	driver/firmware/firmware-zynqmp.c
 F:	drivers/fpga/zynqpl.c
 F:	drivers/gpio/zynq_gpio.c
+F:	drivers/gpio/zynqmp_gpio_modepin.c
 F:	drivers/i2c/i2c-cdns.c
 F:	drivers/i2c/muxes/pca954x.c
 F:	drivers/i2c/zynq_i2c.c

arch/arm/Kconfig

@@ -1214,6 +1214,7 @@ config ARCH_ZYNQMP
 	imply FAT_WRITE
 	imply MP
 	imply DM_USB_GADGET
+	imply ZYNQMP_GPIO_MODEPIN if DM_GPIO && USB
 
 config ARCH_TEGRA
 	bool "NVIDIA Tegra"

drivers/gpio/Kconfig

@@ -523,4 +523,13 @@ config NOMADIK_GPIO
 	  into a number of banks each with 32 GPIOs. The GPIOs for a device are
 	  defined in the device tree with one node for each bank.
 
+config ZYNQMP_GPIO_MODEPIN
+	bool "ZynqMP gpio modepin"
+	depends on DM_GPIO
+	help
+	  This config enables the ZynqMP gpio modepin driver. ZynqMP modepin
+	  driver will set and get the status of PS_MODE pins. These modepins
+	  are accessed using xilinx firmware. In modepin register, [3:0] bits
+	  set direction, [7:4] bits read IO, [11:8] bits set/clear IO.
+
 endif

drivers/gpio/Makefile

@@ -69,3 +69,4 @@ obj-$(CONFIG_NX_GPIO)		+= nx_gpio.o
 obj-$(CONFIG_SIFIVE_GPIO)	+= sifive-gpio.o
 obj-$(CONFIG_NOMADIK_GPIO)	+= nmk_gpio.o
 obj-$(CONFIG_MAX7320_GPIO)	+= max7320_gpio.o
+obj-$(CONFIG_ZYNQMP_GPIO_MODEPIN)	+= zynqmp_gpio_modepin.o

drivers/gpio/zynqmp_gpio_modepin.c

@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ZynqMP GPIO modepin driver
+ *
+ * Copyright (C) 2021 Xilinx, Inc.
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+#include <dm.h>
+#include <asm/arch/hardware.h>
+#include <zynqmp_firmware.h>
+
+#define OUTEN(pin)		(BIT(0) << (pin))
+#define INVAL(pin)		(BIT(4) << (pin))
+#define OUTVAL(pin)		(BIT(8) << (pin))
+
+#define ZYNQMP_CRL_APB_BOOTPIN_CTRL_MASK	0xF0F
+#define ZYNQMP_CRL_APB_BOOT_PIN_CTRL		(ZYNQMP_CRL_APB_BASEADDR + \
+						(0x250U))
+
+static int get_gpio_modepin(u32 *ret_payload)
+{
+	return xilinx_pm_request(PM_MMIO_READ, ZYNQMP_CRL_APB_BOOT_PIN_CTRL,
+				 0, 0, 0, ret_payload);
+}
+
+static int set_gpio_modepin(int val)
+{
+	return xilinx_pm_request(PM_MMIO_WRITE, ZYNQMP_CRL_APB_BOOT_PIN_CTRL,
+				 ZYNQMP_CRL_APB_BOOTPIN_CTRL_MASK,
+				 val, 0, NULL);
+}
+
+static int modepin_gpio_direction_input(struct udevice *dev,
+					unsigned int offset)
+{
+	return 0;
+}
+
+static int modepin_gpio_set_value(struct udevice *dev, unsigned int offset,
+				  int value)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	u32 out_val = 0;
+	int ret;
+
+	ret = get_gpio_modepin(ret_payload);
+	if (value)
+		out_val = OUTVAL(offset) | ret_payload[1];
+	else
+		out_val = ~OUTVAL(offset) & ret_payload[1];
+
+	return set_gpio_modepin(out_val);
+}
+
+static int modepin_gpio_direction_output(struct udevice *dev,
+					 unsigned int offset, int value)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	u32 out_en = 0;
+	int ret;
+
+	ret = get_gpio_modepin(ret_payload);
+	if (ret)
+		return ret;
+
+	if (value)
+		out_en = OUTEN(offset) | ret_payload[1];
+	else
+		out_en = ~OUTEN(offset) & ret_payload[1];
+
+	ret = set_gpio_modepin(out_en);
+	if (ret)
+		return ret;
+
+	return modepin_gpio_set_value(dev, offset, value);
+}
+
+static int modepin_gpio_xlate(struct udevice *dev, struct gpio_desc *desc,
+			      struct ofnode_phandle_args *args)
+{
+	desc->offset = args->args[0];
+
+	return 0;
+}
+
+static int modepin_gpio_get_value(struct udevice *dev, unsigned int offset)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	int ret;
+
+	ret = get_gpio_modepin(ret_payload);
+	if (ret)
+		return ret;
+
+	return (INVAL(offset) & ret_payload[1]) ? 1 : 0;
+}
+
+static int modepin_gpio_get_function(struct udevice *dev, unsigned int offset)
+{
+	u32 ret_payload[PAYLOAD_ARG_CNT];
+	int ret;
+
+	ret = get_gpio_modepin(ret_payload);
+	if (ret)
+		return ret;
+
+	return (OUTEN(offset) & ret_payload[1]) ? GPIOF_OUTPUT : GPIOF_INPUT;
+}
+
+static const struct dm_gpio_ops modepin_gpio_ops = {
+	.direction_input = modepin_gpio_direction_input,
+	.direction_output = modepin_gpio_direction_output,
+	.get_value = modepin_gpio_get_value,
+	.set_value = modepin_gpio_set_value,
+	.get_function = modepin_gpio_get_function,
+	.xlate = modepin_gpio_xlate,
+};
+
+static int modepin_gpio_probe(struct udevice *dev)
+{
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	const void *label_ptr;
+
+	label_ptr = dev_read_prop(dev, "label", NULL);
+	if (label_ptr) {
+		uc_priv->bank_name = strdup(label_ptr);
+		if (!uc_priv->bank_name)
+			return -ENOMEM;
+	} else {
+		uc_priv->bank_name = dev->name;
+	}
+
+	uc_priv->gpio_count = 4;
+
+	return 0;
+}
+
+static const struct udevice_id modepin_gpio_ids[] = {
+	{ .compatible = "xlnx,zynqmp-gpio-modepin",},
+	{ }
+};
+
+U_BOOT_DRIVER(modepin_gpio) = {
+	.name = "modepin_gpio",
+	.id = UCLASS_GPIO,
+	.ops = &modepin_gpio_ops,
+	.of_match = modepin_gpio_ids,
+	.probe = modepin_gpio_probe,
+};