gpio: Add SpacemiT K1-X gpio driver

GPIO driver is a dependence for many devices like SD card, ethernet.
Port it from the vendor kernel [1].

[1] - https://github.com/BPI-SINOVOIP/pi-linux.git

Change-Id: Ibc7d674aeaf2e725bf34e5a6928532bcfe18e9a0
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>

3 files changed, 438 insertions, 0 deletions

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d56b835359d3..7c41dd9a2a74 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -124,6 +124,15 @@ config GPIO_IDIO_16
 menu "Memory mapped GPIO drivers"
 	depends on HAS_IOMEM
 
+config GPIO_K1X
+	bool "SPACEMIT-K1X GPIO support"
+	depends on ARCH_SPACEMIT
+	help
+	  Say yes here to support the K1X GPIO device.
+	  The K1X GPIO device may have several banks, and each
+	  bank control at most 32 GPIO pins. The number of banks
+	  is passed by device tree or platform data.
+
 config GPIO_74XX_MMIO
 	tristate "GPIO driver for 74xx-ICs with MMIO access"
 	depends on OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index eb73b5d633eb..59fed8362317 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -195,3 +195,4 @@ obj-$(CONFIG_GPIO_XTENSA)		+= gpio-xtensa.o
 obj-$(CONFIG_GPIO_ZEVIO)		+= gpio-zevio.o
 obj-$(CONFIG_GPIO_ZYNQ)			+= gpio-zynq.o
 obj-$(CONFIG_GPIO_ZYNQMP_MODEPIN)	+= gpio-zynqmp-modepin.o
+obj-$(CONFIG_GPIO_K1X)			+= gpio-k1x.o
\ No newline at end of file
diff --git a/drivers/gpio/gpio-k1x.c b/drivers/gpio/gpio-k1x.c
new file mode 100644
index 000000000000..58c1bd2f04aa
--- /dev/null
+++ b/drivers/gpio/gpio-k1x.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * spacemit-k1x gpio driver file
+ *
+ * Copyright (C) 2023 Spacemit
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/clk.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/irqdomain.h>
+#include <linux/gpio/driver.h>
+#include <linux/device.h>
+#include <linux/of.h>
+
+
+#define GPLR		0x0
+#define GPDR		0xc
+#define GPSR		0x18
+#define GPCR		0x24
+#define GRER		0x30
+#define GFER		0x3c
+#define GEDR		0x48
+#define GSDR		0x54
+#define GCDR		0x60
+#define GSRER		0x6c
+#define GCRER		0x78
+#define GSFER		0x84
+#define GCFER		0x90
+#define GAPMASK		0x9c
+#define GCPMASK		0xa8
+
+#define K1X_BANK_GPIO_NUMBER	(32)
+#define BANK_GPIO_MASK		(K1X_BANK_GPIO_NUMBER - 1)
+
+#define k1x_gpio_to_bank_idx(gpio)	((gpio)/K1X_BANK_GPIO_NUMBER)
+#define k1x_gpio_to_bank_offset(gpio)	((gpio) & BANK_GPIO_MASK)
+#define k1x_bank_to_gpio(idx, offset)	(((idx) * K1X_BANK_GPIO_NUMBER)	\
+						| ((offset) & BANK_GPIO_MASK))
+
+struct k1x_gpio_bank {
+	void __iomem *reg_bank;
+	u32 irq_mask;
+	u32 irq_rising_edge;
+	u32 irq_falling_edge;
+};
+
+struct k1x_gpio_chip {
+	struct gpio_chip chip;
+	void __iomem *reg_base;
+	int irq;
+	struct irq_domain *domain;
+	unsigned int ngpio;
+	unsigned int nbank;
+	struct k1x_gpio_bank *banks;
+};
+
+static int k1x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+
+	return irq_create_mapping(k1x_chip->domain, offset);
+}
+
+static int k1x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(offset)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(offset));
+
+	writel(bit, bank->reg_bank + GCDR);
+
+	return 0;
+}
+
+static int k1x_gpio_direction_output(struct gpio_chip *chip,
+				     unsigned offset, int value)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(offset)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(offset));
+
+	/* Set value first. */
+	writel(bit, bank->reg_bank + (value ? GPSR : GPCR));
+
+	writel(bit, bank->reg_bank + GSDR);
+
+	return 0;
+}
+
+static int k1x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(offset)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(offset));
+	u32 gplr;
+
+	gplr  = readl(bank->reg_bank + GPLR);
+
+	return !!(gplr & bit);
+}
+
+static void k1x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(offset)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(offset));
+	u32 gpdr;
+
+	gpdr = readl(bank->reg_bank + GPDR);
+	/* Is it configured as output? */
+	if (gpdr & bit)
+		writel(bit, bank->reg_bank + (value ? GPSR : GPCR));
+}
+
+#ifdef CONFIG_OF_GPIO
+static int k1x_gpio_of_xlate(struct gpio_chip *chip,
+			     const struct of_phandle_args *gpiospec,
+			     u32 *flags)
+{
+	struct k1x_gpio_chip *k1x_chip =
+			container_of(chip, struct k1x_gpio_chip, chip);
+
+	/* GPIO index start from 0. */
+	if (gpiospec->args[0] >= k1x_chip->ngpio)
+		return -EINVAL;
+
+	if (flags)
+		*flags = gpiospec->args[1];
+
+	return gpiospec->args[0];
+}
+#endif
+
+static int k1x_gpio_irq_type(struct irq_data *d, unsigned int type)
+{
+	struct k1x_gpio_chip *k1x_chip = irq_data_get_irq_chip_data(d);
+	int gpio = irqd_to_hwirq(d);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(gpio)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(gpio));
+
+	if (type & IRQ_TYPE_EDGE_RISING) {
+		bank->irq_rising_edge |= bit;
+		writel(bit, bank->reg_bank + GSRER);
+	} else {
+		bank->irq_rising_edge &= ~bit;
+		writel(bit, bank->reg_bank + GCRER);
+	}
+
+	if (type & IRQ_TYPE_EDGE_FALLING) {
+		bank->irq_falling_edge |= bit;
+		writel(bit, bank->reg_bank + GSFER);
+	} else {
+		bank->irq_falling_edge &= ~bit;
+		writel(bit, bank->reg_bank + GCFER);
+	}
+
+	return 0;
+}
+
+static irqreturn_t k1x_gpio_demux_handler(int irq, void *data)
+{
+	struct k1x_gpio_chip *k1x_chip = (struct k1x_gpio_chip *)data;
+	struct k1x_gpio_bank *bank;
+	int i, n;
+	u32 gedr;
+	unsigned long pending = 0;
+	unsigned int irqs_handled = 0;
+
+	for (i = 0; i < k1x_chip->nbank; i++) {
+		bank = &k1x_chip->banks[i];
+
+		gedr = readl(bank->reg_bank + GEDR);
+		if (!gedr)
+			continue;
+
+		writel(gedr, bank->reg_bank + GEDR);
+		gedr = gedr & bank->irq_mask;
+
+		if (!gedr)
+			continue;
+		pending = gedr;
+		for_each_set_bit(n, &pending, BITS_PER_LONG) {
+			generic_handle_irq(irq_find_mapping(k1x_chip->domain,
+						k1x_bank_to_gpio(i, n)));
+		}
+		irqs_handled++;
+	}
+
+	return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void k1x_ack_muxed_gpio(struct irq_data *d)
+{
+	struct k1x_gpio_chip *k1x_chip = irq_data_get_irq_chip_data(d);
+	int gpio = irqd_to_hwirq(d);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(gpio)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(gpio));
+
+	writel(bit, bank->reg_bank + GEDR);
+}
+
+static void k1x_mask_muxed_gpio(struct irq_data *d)
+{
+	struct k1x_gpio_chip *k1x_chip = irq_data_get_irq_chip_data(d);
+	int gpio = irqd_to_hwirq(d);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(gpio)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(gpio));
+
+	bank->irq_mask &= ~bit;
+
+	/* Clear the bit of rising and falling edge detection. */
+	writel(bit, bank->reg_bank + GCRER);
+	writel(bit, bank->reg_bank + GCFER);
+}
+
+static void k1x_unmask_muxed_gpio(struct irq_data *d)
+{
+	struct k1x_gpio_chip *k1x_chip = irq_data_get_irq_chip_data(d);
+	int gpio = irqd_to_hwirq(d);
+	struct k1x_gpio_bank *bank =
+			&k1x_chip->banks[k1x_gpio_to_bank_idx(gpio)];
+	u32 bit = (1 << k1x_gpio_to_bank_offset(gpio));
+
+	bank->irq_mask |= bit;
+
+	/* Set the bit of rising and falling edge detection if the gpio has. */
+	writel(bit & bank->irq_rising_edge, bank->reg_bank + GSRER);
+	writel(bit & bank->irq_falling_edge, bank->reg_bank + GSFER);
+}
+
+static struct irq_chip k1x_muxed_gpio_chip = {
+	.name		= "k1x-gpio-irqchip",
+	.irq_ack	= k1x_ack_muxed_gpio,
+	.irq_mask	= k1x_mask_muxed_gpio,
+	.irq_unmask	= k1x_unmask_muxed_gpio,
+	.irq_set_type	= k1x_gpio_irq_type,
+	.flags		= IRQCHIP_SKIP_SET_WAKE,
+};
+
+static const struct of_device_id k1x_gpio_dt_ids[] = {
+	{ .compatible = "spacemit,k1x-gpio"},
+	{}
+};
+
+static int k1x_irq_domain_map(struct irq_domain *d, unsigned int irq,
+			      irq_hw_number_t hw)
+{
+	irq_set_chip_and_handler(irq, &k1x_muxed_gpio_chip,
+				 handle_edge_irq);
+	irq_set_chip_data(irq, d->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops k1x_gpio_irq_domain_ops = {
+	.map	= k1x_irq_domain_map,
+	.xlate	= irq_domain_xlate_twocell,
+};
+
+static int k1x_gpio_probe_dt(struct platform_device *pdev,
+				struct k1x_gpio_chip *k1x_chip)
+{
+	struct device_node *np = dev_of_node(&pdev->dev);
+	struct device_node *child;
+	u32 offset;
+	int i, nbank, ret;
+
+	nbank = of_get_child_count(np);
+	if (nbank == 0)
+		return -EINVAL;
+
+	k1x_chip->banks = devm_kzalloc(&pdev->dev,
+				sizeof(*k1x_chip->banks) * nbank,
+				GFP_KERNEL);
+	if (k1x_chip->banks == NULL)
+		return -ENOMEM;
+
+	i = 0;
+	for_each_child_of_node(np, child) {
+		ret = of_property_read_u32(child, "reg-offset", &offset);
+		if (ret) {
+			of_node_put(child);
+			return ret;
+		}
+		k1x_chip->banks[i].reg_bank = k1x_chip->reg_base + offset;
+		i++;
+	}
+
+	k1x_chip->nbank = nbank;
+	k1x_chip->ngpio = k1x_chip->nbank * K1X_BANK_GPIO_NUMBER;
+
+	return 0;
+}
+
+static int k1x_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	struct k1x_gpio_chip *k1x_chip;
+	struct k1x_gpio_bank *bank;
+	struct resource *res;
+	struct irq_domain *domain;
+	struct clk *clk;
+
+	int irq, i, ret;
+	void __iomem *base;
+
+	np = dev_of_node(&pdev->dev);
+	if (!np)
+		return -EINVAL;
+
+	k1x_chip = devm_kzalloc(dev, sizeof(*k1x_chip), GFP_KERNEL);
+	if (k1x_chip == NULL)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+	base = devm_ioremap_resource(dev, res);
+	if (!base)
+		return -EINVAL;
+
+	k1x_chip->irq = irq;
+	k1x_chip->reg_base = base;
+
+	ret = k1x_gpio_probe_dt(pdev, k1x_chip);
+	if (ret) {
+		dev_err(dev, "Fail to initialize gpio unit, error %d.\n", ret);
+		return ret;
+	}
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "Fail to get gpio clock, error %ld.\n",
+			PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(dev, "Fail to enable gpio clock, error %d.\n", ret);
+		return ret;
+	}
+
+	domain = irq_domain_add_linear(np, k1x_chip->ngpio,
+					&k1x_gpio_irq_domain_ops, k1x_chip);
+	if (domain == NULL)
+		return -EINVAL;
+
+	k1x_chip->domain = domain;
+
+	/* Initialize the gpio chip */
+	k1x_chip->chip.label = "k1x-gpio";
+	k1x_chip->chip.request = gpiochip_generic_request;
+	k1x_chip->chip.free = gpiochip_generic_free;
+	k1x_chip->chip.direction_input  = k1x_gpio_direction_input;
+	k1x_chip->chip.direction_output = k1x_gpio_direction_output;
+	k1x_chip->chip.get = k1x_gpio_get;
+	k1x_chip->chip.set = k1x_gpio_set;
+	k1x_chip->chip.to_irq = k1x_gpio_to_irq;
+#ifdef CONFIG_OF_GPIO
+	k1x_chip->chip.fwnode = of_fwnode_handle(np);
+	k1x_chip->chip.of_xlate = k1x_gpio_of_xlate;
+	k1x_chip->chip.of_gpio_n_cells = 2;
+#endif
+	k1x_chip->chip.ngpio = k1x_chip->ngpio;
+
+	if (devm_request_irq(&pdev->dev, irq,
+			     k1x_gpio_demux_handler, 0, k1x_chip->chip.label, k1x_chip)) {
+		dev_err(&pdev->dev, "failed to request high IRQ\n");
+		ret = -ENOENT;
+		goto err;
+	}
+
+	gpiochip_add(&k1x_chip->chip);
+
+	/* clear all GPIO edge detects */
+	for (i = 0; i < k1x_chip->nbank; i++) {
+		bank = &k1x_chip->banks[i];
+		writel(0xffffffff, bank->reg_bank + GCFER);
+		writel(0xffffffff, bank->reg_bank + GCRER);
+		/* Unmask edge detection to AP. */
+		writel(0xffffffff, bank->reg_bank + GAPMASK);
+	}
+
+	return 0;
+err:
+	irq_domain_remove(domain);
+	return ret;
+}
+
+static struct platform_driver k1x_gpio_driver = {
+	.probe		= k1x_gpio_probe,
+	.driver		= {
+		.name	= "k1x-gpio",
+		.of_match_table = k1x_gpio_dt_ids,
+	},
+};
+
+static int __init k1x_gpio_init(void)
+{
+	return platform_driver_register(&k1x_gpio_driver);
+}
+subsys_initcall(k1x_gpio_init);