x86: Add a generic Intel GPIO driver

Add a GPIO driver which uses the pinctrl driver to access the pad
information. This driver relies on the GPIO nodes being subnodes to the
pinctrl device.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

doc/device-tree-bindings/gpio/intel,apl-gpio.txt

@@ -0,0 +1,55 @@
+Intel Apollo Lake GPIO controller
+
+The Apollo Lake (APL) GPIO controller is used to control GPIO functions of
+the pins.
+
+Required properties:
+- compatible: "intel,apl-gpio"
+- #gpio-cells: Should be 2. The syntax of the gpio specifier used by client
+  nodes should be the following with values derived from the SoC user manual.
+     <[phandle of the gpio controller node]
+      [pin number within the gpio controller]
+      [flags]>
+
+  Values for gpio specifier:
+  - Pin number: is a GPIO pin number between 0 and 244
+  - Flags: GPIO_ACTIVE_HIGH or GPIO_ACTIVE_LOW
+
+- gpio-controller: Specifies that the node is a gpio controller.
+
+Example:
+
+...
+{
+	p2sb: p2sb@d,0 {
+		reg = <0x02006810 0 0 0 0>;
+		compatible = "intel,apl-p2sb";
+		early-regs = <IOMAP_P2SB_BAR 0x100000>;
+
+		north {
+			compatible = "intel,apl-pinctrl";
+			intel,p2sb-port-id = <PID_GPIO_N>;
+			gpio_n: gpio-n {
+				compatible = "intel,gpio";
+				gpio-controller;
+				#gpio-cells = <2>;
+			};
+		};
+	};
+
+	i2c_2: i2c2@16,2 {
+		compatible = "intel,apl-i2c", "snps,designware-i2c-pci";
+		reg = <0x0200b210 0 0 0 0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clock-frequency = <400000>;
+		tpm@50 {
+			reg = <0x50>;
+			compatible = "google,cr50";
+			u-boot,i2c-offset-len = <0>;
+			ready-gpio = <&gpio_n GPIO_28 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+};
+...

drivers/gpio/Kconfig

@@ -104,6 +104,15 @@ config INTEL_BROADWELL_GPIO
 	  driver from the common Intel ICH6 driver. It supports a total of
 	  95 GPIOs which can be configured from the device tree.
 
+config INTEL_GPIO
+	bool "Intel generic GPIO driver"
+	depends on DM_GPIO
+	help
+	  Say yes here to select Intel generic GPIO driver. This controller
+	  supports recent chips (e.g. Apollo Lake). It permits basic GPIO
+	  control including setting pins to input/output. It makes use of its
+	  parent pinctrl driver to actually effect changes.
+
 config INTEL_ICH6_GPIO
 	bool "Intel ICH6 compatible legacy GPIO driver"
 	depends on DM_GPIO

drivers/gpio/Makefile

@@ -17,6 +17,7 @@ endif
 obj-$(CONFIG_AT91_GPIO)	+= at91_gpio.o
 obj-$(CONFIG_ATMEL_PIO4)	+= atmel_pio4.o
 obj-$(CONFIG_BCM6345_GPIO)	+= bcm6345_gpio.o
+obj-$(CONFIG_INTEL_GPIO)	+= intel_gpio.o
 obj-$(CONFIG_INTEL_ICH6_GPIO)	+= intel_ich6_gpio.o
 obj-$(CONFIG_INTEL_BROADWELL_GPIO)	+= intel_broadwell_gpio.o
 obj-$(CONFIG_KIRKWOOD_GPIO)	+= kw_gpio.o

drivers/gpio/intel_gpio.c

@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <p2sb.h>
+#include <pch.h>
+#include <pci.h>
+#include <syscon.h>
+#include <asm/cpu.h>
+#include <asm/gpio.h>
+#include <asm/intel_pinctrl.h>
+#include <asm/intel_pinctrl_defs.h>
+#include <asm/io.h>
+#include <asm/pci.h>
+#include <asm/arch/gpio.h>
+#include <dt-bindings/gpio/x86-gpio.h>
+
+static int intel_gpio_direction_input(struct udevice *dev, uint offset)
+{
+	struct udevice *pinctrl = dev_get_parent(dev);
+	uint config_offset = intel_pinctrl_get_config_reg_addr(pinctrl, offset);
+
+	pcr_clrsetbits32(pinctrl, config_offset,
+			 PAD_CFG0_MODE_MASK | PAD_CFG0_TX_STATE |
+				  PAD_CFG0_RX_DISABLE,
+			 PAD_CFG0_MODE_GPIO | PAD_CFG0_TX_DISABLE);
+
+	return 0;
+}
+
+static int intel_gpio_direction_output(struct udevice *dev, uint offset,
+				       int value)
+{
+	struct udevice *pinctrl = dev_get_parent(dev);
+	uint config_offset = intel_pinctrl_get_config_reg_addr(pinctrl, offset);
+
+	pcr_clrsetbits32(dev, config_offset,
+			 PAD_CFG0_MODE_MASK | PAD_CFG0_RX_STATE |
+				  PAD_CFG0_TX_DISABLE,
+			 PAD_CFG0_MODE_GPIO | PAD_CFG0_RX_DISABLE |
+				  (value ? PAD_CFG0_TX_STATE : 0));
+
+	return 0;
+}
+
+static int intel_gpio_get_value(struct udevice *dev, uint offset)
+{
+	struct udevice *pinctrl = dev_get_parent(dev);
+	uint mode, rx_tx;
+	u32 reg;
+
+	reg = intel_pinctrl_get_config_reg(pinctrl, offset);
+	mode = (reg & PAD_CFG0_MODE_MASK) >> PAD_CFG0_MODE_SHIFT;
+	if (!mode) {
+		rx_tx = reg & (PAD_CFG0_TX_DISABLE | PAD_CFG0_RX_DISABLE);
+		if (rx_tx == PAD_CFG0_TX_DISABLE)
+			return mode & PAD_CFG0_RX_STATE_BIT ? 1 : 0;
+		else if (rx_tx == PAD_CFG0_RX_DISABLE)
+			return mode & PAD_CFG0_TX_STATE_BIT ? 1 : 0;
+	}
+
+	return 0;
+}
+
+static int intel_gpio_set_value(struct udevice *dev, unsigned offset, int value)
+{
+	struct udevice *pinctrl = dev_get_parent(dev);
+	uint config_offset = intel_pinctrl_get_config_reg_addr(pinctrl, offset);
+
+	pcr_clrsetbits32(dev, config_offset, PAD_CFG0_TX_STATE,
+			 value ? PAD_CFG0_TX_STATE : 0);
+
+	return 0;
+}
+
+static int intel_gpio_get_function(struct udevice *dev, uint offset)
+{
+	struct udevice *pinctrl = dev_get_parent(dev);
+	uint mode, rx_tx;
+	u32 reg;
+
+	reg = intel_pinctrl_get_config_reg(pinctrl, offset);
+	mode = (reg & PAD_CFG0_MODE_MASK) >> PAD_CFG0_MODE_SHIFT;
+	if (!mode) {
+		rx_tx = reg & (PAD_CFG0_TX_DISABLE | PAD_CFG0_RX_DISABLE);
+		if (rx_tx == PAD_CFG0_TX_DISABLE)
+			return GPIOF_INPUT;
+		else if (rx_tx == PAD_CFG0_RX_DISABLE)
+			return GPIOF_OUTPUT;
+	}
+
+	return GPIOF_FUNC;
+}
+
+static int intel_gpio_xlate(struct udevice *orig_dev, struct gpio_desc *desc,
+			    struct ofnode_phandle_args *args)
+{
+	struct udevice *pinctrl, *dev;
+	int gpio, ret;
+
+	/*
+	 * GPIO numbers are global in the device tree so it doesn't matter
+	 * which one is used
+	 */
+	gpio = args->args[0];
+	ret = intel_pinctrl_get_pad(gpio, &pinctrl, &desc->offset);
+	if (ret)
+		return log_msg_ret("bad", ret);
+	device_find_first_child(pinctrl, &dev);
+	if (!dev)
+		return log_msg_ret("no child", -ENOENT);
+	desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0;
+	desc->dev = dev;
+
+	return 0;
+}
+
+static int intel_gpio_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+static int intel_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+	struct gpio_dev_priv *upriv = dev_get_uclass_priv(dev);
+	struct intel_pinctrl_priv *pinctrl_priv = dev_get_priv(dev->parent);
+	const struct pad_community *comm = pinctrl_priv->comm;
+
+	upriv->gpio_count = comm->last_pad - comm->first_pad + 1;
+	upriv->bank_name = dev->name;
+
+	return 0;
+}
+
+static const struct dm_gpio_ops gpio_intel_ops = {
+	.direction_input	= intel_gpio_direction_input,
+	.direction_output	= intel_gpio_direction_output,
+	.get_value		= intel_gpio_get_value,
+	.set_value		= intel_gpio_set_value,
+	.get_function		= intel_gpio_get_function,
+	.xlate			= intel_gpio_xlate,
+};
+
+static const struct udevice_id intel_intel_gpio_ids[] = {
+	{ .compatible = "intel,gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpio_intel) = {
+	.name	= "gpio_intel",
+	.id	= UCLASS_GPIO,
+	.of_match = intel_intel_gpio_ids,
+	.ops	= &gpio_intel_ops,
+	.ofdata_to_platdata	= intel_gpio_ofdata_to_platdata,
+	.probe	= intel_gpio_probe,
+};