[PATCH v2 1/2] drivers: gpio: add broadcom iproc gpio driver support

[Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>]

Add gpio driver support for Broadcom iproc-based socs.

Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
---
 drivers/gpio/Kconfig      |  10 ++
 drivers/gpio/Makefile     |   1 +
 drivers/gpio/iproc_gpio.c | 259 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 270 insertions(+)
 create mode 100644 drivers/gpio/iproc_gpio.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 2081520f42..a04b4af1b5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -135,6 +135,16 @@ config IMX_RGPIO2P
 	help
 	  This driver supports i.MX7ULP Rapid GPIO2P controller.
 
+config IPROC_GPIO
+	bool "Broadcom iProc GPIO driver(without pinconf)"
+	default n
+	help
+	  The Broadcom iProc based SoCs- Cygnus, NS2, NS3, NSP and Stingray,
+	  use same GPIO Controller IP hence this driver could be used for all.
+
+	  The Broadcom iProc based SoCs have multiple GPIO controllers and only
+	  the always-ON GPIO controller (CRMU/AON) is supported by this driver.
+
 config HSDK_CREG_GPIO
 	bool "HSDK CREG GPIO griver"
 	depends on DM_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 7638259007..5dc5849477 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_CORTINA_GPIO)      += cortina_gpio.o
 obj-$(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-$(CONFIG_IPROC_GPIO)	+= iproc_gpio.o
 obj-$(CONFIG_KIRKWOOD_GPIO)	+= kw_gpio.o
 obj-$(CONFIG_KONA_GPIO)	+= kona_gpio.o
 obj-$(CONFIG_MARVELL_GPIO)	+= mvgpio.o
diff --git a/drivers/gpio/iproc_gpio.c b/drivers/gpio/iproc_gpio.c
new file mode 100644
index 0000000000..037f1a7de5
--- /dev/null
+++ b/drivers/gpio/iproc_gpio.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier:      GPL-2.0+
+/*
+ * Copyright (C) 2020 Broadcom
+ */
+
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <common.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <dm/devres.h>
+#include <dm/pinctrl.h>
+#include <errno.h>
+
+/*
+ * There are five GPIO bank register. Each bank can configure max of 32 gpios.
+ * BANK0 - gpios 0 to 31
+ * BANK1 - gpios 32 to 63
+ * BANK2 - gpios 64 to 95
+ * BANK3 - gpios 96 to 127
+ * BANK4 - gpios 128 to 150
+ *
+ * Offset difference between consecutive bank register is 0x200
+ */
+#define IPROC_GPIO_PER_BANK         32
+#define IPROC_GPIO_SHIFT(n)         ((n) % IPROC_GPIO_PER_BANK)
+#define IPROC_GPIO_BANK_OFFSET(n)   (0x200 * ((n) / IPROC_GPIO_PER_BANK))
+#define IPROC_GPIO_REG(pin, reg)    (IPROC_GPIO_BANK_OFFSET(pin) + (reg))
+
+#define IPROC_GPIO_DATA_IN_OFFSET   0x00
+#define IPROC_GPIO_DATA_OUT_OFFSET  0x04
+#define IPROC_GPIO_OUT_EN_OFFSET    0x08
+
+struct iproc_gpio_pctrl_map {
+	u32 gpio_pin;
+	u32 pctrl_pin;
+	u32 npins;
+	struct list_head node;
+};
+
+struct iproc_gpio_platdata {
+	struct udevice *pinctrl_dev;
+	struct list_head gpiomap;
+	/* register base for this bank */
+	void __iomem *base;
+	char *name;
+	u32 ngpios;
+};
+
+/**
+ *  iproc_gpio_set_bit - set or clear one bit (corresponding to the GPIO pin)
+ *  in a iproc GPIO register
+ *
+ *  @iproc_gpio: Iproc GPIO device
+ *  @reg: register offset
+ *  @gpio: GPIO pin
+ *  @set: set or clear
+ */
+static inline void iproc_gpio_set_bit(struct iproc_gpio_platdata *plat,
+				      u32 reg,
+				      u32 gpio, bool set)
+{
+	u32 offset = IPROC_GPIO_REG(gpio, reg);
+	u32 shift = IPROC_GPIO_SHIFT(gpio);
+	u32 val;
+
+	val = readl(plat->base + offset);
+	if (set)
+		val |= BIT(shift);
+	else
+		val &= ~BIT(shift);
+	writel(val, plat->base + offset);
+}
+
+static inline bool iproc_gpio_get_bit(struct iproc_gpio_platdata *plat,
+				      u32 reg,
+				      u32 gpio)
+{
+	u32 offset = IPROC_GPIO_REG(gpio, reg);
+	u32 shift = IPROC_GPIO_SHIFT(gpio);
+
+	return !!(readl(plat->base + offset) & BIT(shift));
+}
+
+static u32 iproc_get_pctrl_from_gpio(struct iproc_gpio_platdata *plat, u32 gpio)
+{
+	struct iproc_gpio_pctrl_map *range = NULL;
+	struct list_head *pos, *tmp;
+	u32 ret = 0;
+
+	list_for_each_safe(pos, tmp, &plat->gpiomap) {
+		range = list_entry(pos, struct iproc_gpio_pctrl_map, node);
+		if (gpio == range->gpio_pin ||
+		    (gpio < (range->gpio_pin + range->npins))) {
+			ret = (range->pctrl_pin + (gpio - range->gpio_pin));
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int iproc_get_gpio_pctrl_mapping(struct udevice *dev)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+	struct iproc_gpio_pctrl_map *range = NULL;
+	struct ofnode_phandle_args args;
+	int node = dev_of_offset(dev);
+	int index = 0, ret;
+
+	for (;; index++) {
+		ret = dev_read_phandle_with_args(dev, "gpio-ranges",
+						 NULL, 3, index, &args);
+		if (ret)
+			break;
+
+		range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
+		if (!range)
+			return -ENOMEM;
+
+		range->gpio_pin = args.args[0];
+		range->pctrl_pin = args.args[1];
+		range->npins = args.args[2];
+		list_add_tail(&range->node, &plat->gpiomap);
+	}
+
+	return 0;
+}
+
+static int iproc_gpio_request(struct udevice *dev, u32 gpio, const char *label)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+	u32 pctrl;
+
+	if (!plat->pinctrl_dev)
+		return 0;
+
+	pctrl = iproc_get_pctrl_from_gpio(plat, gpio);
+	return pinctrl_request(plat->pinctrl_dev, pctrl, 0);
+}
+
+static int iproc_gpio_direction_input(struct udevice *dev, u32 gpio)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+
+	iproc_gpio_set_bit(plat, IPROC_GPIO_OUT_EN_OFFSET, gpio, false);
+	dev_dbg(dev, "gpio:%u set input\n", gpio);
+	return 0;
+}
+
+static int iproc_gpio_direction_output(struct udevice *dev, u32 gpio,
+				       int value)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+
+	iproc_gpio_set_bit(plat, IPROC_GPIO_OUT_EN_OFFSET, gpio, true);
+	iproc_gpio_set_bit(plat, IPROC_GPIO_DATA_OUT_OFFSET, gpio, !!value);
+	dev_dbg(dev, "gpio:%u set output, value:%d\n", gpio, value);
+
+	return 0;
+}
+
+static int iproc_gpio_get_value(struct udevice *dev, u32 gpio)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+	int value;
+
+	value = iproc_gpio_get_bit(plat, IPROC_GPIO_DATA_IN_OFFSET, gpio);
+	dev_dbg(dev, "gpio:%u get, value:%d\n", gpio, value);
+
+	return value;
+}
+
+static int iproc_gpio_set_value(struct udevice *dev, u32 gpio, int value)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+
+	if (iproc_gpio_get_bit(plat, IPROC_GPIO_OUT_EN_OFFSET, gpio))
+		iproc_gpio_set_bit(plat, IPROC_GPIO_DATA_OUT_OFFSET, gpio,
+				   !!value);
+
+	dev_dbg(dev, "gpio:%u set, value:%d\n", gpio, value);
+	return 0;
+}
+
+static int iproc_gpio_get_function(struct udevice *dev, u32 gpio)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+
+	if (iproc_gpio_get_bit(plat, IPROC_GPIO_OUT_EN_OFFSET, gpio))
+		return GPIOF_OUTPUT;
+	else
+		return GPIOF_INPUT;
+}
+
+static int iproc_gpio_ofdata_to_platdata(struct udevice *dev)
+{
+	struct iproc_gpio_platdata *plat = dev_get_platdata(dev);
+	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+	int ret;
+	char name[10];
+
+	plat->base = dev_read_addr_ptr(dev);
+	if (!plat->base) {
+		dev_err(dev, "%s: Failed to get base address\n", __func__);
+		return -EINVAL;
+	}
+
+	ret = dev_read_u32(dev, "ngpios", &plat->ngpios);
+	if (ret < 0) {
+		dev_err(dev, "%s: Failed to get ngpios\n", __func__);
+		return ret;
+	}
+
+	uclass_get_device_by_phandle(UCLASS_PINCTRL, dev, "gpio-ranges",
+				     &plat->pinctrl_dev);
+
+	INIT_LIST_HEAD(&plat->gpiomap);
+	ret = iproc_get_gpio_pctrl_mapping(dev);
+	if (ret) {
+		dev_err(dev, "%s: Failed to get gpio to pctrl map ret(%d)\n",
+			__func__, ret);
+		return ret;
+	}
+
+	snprintf(name, sizeof(name), "GPIO%d", dev->req_seq);
+	plat->name = strdup(name);
+
+	uc_priv->gpio_count = plat->ngpios;
+	uc_priv->bank_name = plat->name;
+
+	dev_info(dev, ":bank name(%s) base %p, #gpios %d\n",
+		 plat->name, plat->base, plat->ngpios);
+
+	return 0;
+}
+
+static const struct dm_gpio_ops iproc_gpio_ops = {
+	.request		= iproc_gpio_request,
+	.direction_input	= iproc_gpio_direction_input,
+	.direction_output	= iproc_gpio_direction_output,
+	.get_value		= iproc_gpio_get_value,
+	.set_value		= iproc_gpio_set_value,
+	.get_function		= iproc_gpio_get_function,
+};
+
+static const struct udevice_id iproc_gpio_ids[] = {
+	{ .compatible = "brcm,iproc-gpio" },
+	{ }
+};
+
+U_BOOT_DRIVER(iproc_gpio) = {
+	.name			= "iproc_gpio",
+	.id			= UCLASS_GPIO,
+	.of_match		= iproc_gpio_ids,
+	.ops			= &iproc_gpio_ops,
+	.ofdata_to_platdata	= iproc_gpio_ofdata_to_platdata,
+	.platdata_auto_alloc_size	= sizeof(struct iproc_gpio_platdata),
+};
-- 
2.17.1