[RFC PATH 2/2] gpio: starfive-jh7100: Add StarFive JH7100 GPIO driver

From: Drew Fustini
Date: Wed Jun 30 2021 - 20:22:36 EST


Add GPIO driver for the StarFive JH7100 SoC [1] used on the
BeagleV Starlight JH7100 board [2].

[1] https://github.com/starfive-tech/beaglev_doc/
[2] https://github.com/beagleboard/beaglev-starlight

Signed-off-by: Emil Renner Berthing <kernel@xxxxxxxx>
Signed-off-by: Huan Feng <huan.feng@xxxxxxxxxxxxxxxx>
Signed-off-by: Drew Fustini <drew@xxxxxxxxxxxxxxx>
---
MAINTAINERS | 8 +
drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-starfive-jh7100.c | 425 ++++++++++++++++++++++++++++
4 files changed, 442 insertions(+)
create mode 100644 drivers/gpio/gpio-starfive-jh7100.c

diff --git a/MAINTAINERS b/MAINTAINERS
index bc0ceef87b73..04fccc2ceffa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17423,6 +17423,14 @@ S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
F: drivers/staging/

+SIFVE JH7100 SOC GPIO DRIVER
+M: Drew Fustini <drew@xxxxxxxxxxxxxxx>
+M: Huan Feng <huan.feng@xxxxxxxxxxxxxxxx>
+L: linux-riscv@xxxxxxxxxxxxxxxxxxx
+L: linux-gpio@xxxxxxxxxxxxxxx
+F: Documentation/devicetree/bindings/gpio/starfive,jh7100-gpio.yaml
+F: drivers/gpio/gpio-starfive-jh7100.c
+
STARFIRE/DURALAN NETWORK DRIVER
M: Ion Badulescu <ionut@xxxxxxxxxx>
S: Odd Fixes
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 1dd0ec6727fd..26630e4852c0 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -542,6 +542,14 @@ config GPIO_SIFIVE
help
Say yes here to support the GPIO device on SiFive SoCs.

+config GPIO_STARFIVE_JH7100
+ bool "StarFive JH7100 GPIO support"
+ depends on OF_GPIO
+ select GPIOLIB_IRQCHIP
+ default y if SOC_STARFIVE_VIC7100
+ help
+ Say yes here to support the GPIO device on StarFive JH7100 SoC.
+
config GPIO_SIOX
tristate "SIOX GPIO support"
depends on SIOX
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d7c81e1611a4..939922eaf5f3 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -132,6 +132,7 @@ obj-$(CONFIG_GPIO_SAMA5D2_PIOBU) += gpio-sama5d2-piobu.o
obj-$(CONFIG_GPIO_SCH311X) += gpio-sch311x.o
obj-$(CONFIG_GPIO_SCH) += gpio-sch.o
obj-$(CONFIG_GPIO_SIFIVE) += gpio-sifive.o
+obj-$(CONFIG_GPIO_STARFIVE_JH7100) += gpio-starfive-jh7100.o
obj-$(CONFIG_GPIO_SIOX) += gpio-siox.o
obj-$(CONFIG_GPIO_SL28CPLD) += gpio-sl28cpld.o
obj-$(CONFIG_GPIO_SODAVILLE) += gpio-sodaville.o
diff --git a/drivers/gpio/gpio-starfive-jh7100.c b/drivers/gpio/gpio-starfive-jh7100.c
new file mode 100644
index 000000000000..b94ebfe9eaf7
--- /dev/null
+++ b/drivers/gpio/gpio-starfive-jh7100.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * GPIO driver for StarFive JH7100 SoC
+ *
+ * Copyright (C) 2020 Shanghai StarFive Technology Co., Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+/*
+ * refer to Section 12. GPIO Registers in JH7100 datasheet:
+ * https://github.com/starfive-tech/beaglev_doc
+ */
+
+/* global enable */
+#define GPIO_EN 0x0
+
+/* interrupt type */
+#define GPIO_IS_LOW 0x10
+#define GPIO_IS_HIGH 0x14
+
+/* edge trigger interrupt type */
+#define GPIO_IBE_LOW 0x18
+#define GPIO_IBE_HIGH 0x1c
+
+/* edge trigger interrupt polarity */
+#define GPIO_IEV_LOW 0x20
+#define GPIO_IEV_HIGH 0x24
+
+/* interrupt max */
+#define GPIO_IE_LOW 0x28
+#define GPIO_IE_HIGH 0x2c
+
+/* clear edge-triggered interrupt */
+#define GPIO_IC_LOW 0x30
+#define GPIO_IC_HIGH 0x34
+
+/* edge-triggered interrupt status (read-only) */
+#define GPIO_RIS_LOW 0x38
+#define GPIO_RIS_HIGH 0x3c
+
+/* interrupt status after masking (read-only) */
+#define GPIO_MIS_LOW 0x40
+#define GPIO_MIS_HIGH 0x44
+
+/* data value of gpio */
+#define GPIO_DIN_LOW 0x48
+#define GPIO_DIN_HIGH 0x4c
+
+/* GPIO0_DOUT_CFG is 0x50, GPIOn_DOUT_CFG is 0x50+(n*8) */
+#define GPIO_DOUT_X_REG 0x50
+
+/* GPIO0_DOEN_CFG is 0x54, GPIOn_DOEN_CFG is 0x54+(n*8) */
+#define GPIO_DOEN_X_REG 0x54
+
+#define MAX_GPIO 64
+
+struct starfive_gpio {
+ raw_spinlock_t lock;
+ void __iomem *base;
+ struct gpio_chip gc;
+ unsigned long enabled;
+ unsigned int trigger[MAX_GPIO];
+ unsigned int irq_parent[MAX_GPIO];
+};
+
+static int starfive_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ raw_spin_lock_irqsave(&chip->lock, flags);
+ writel_relaxed(0x1, chip->base + GPIO_DOEN_X_REG + offset * 8);
+ raw_spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static int starfive_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ raw_spin_lock_irqsave(&chip->lock, flags);
+ writel_relaxed(0x0, chip->base + GPIO_DOEN_X_REG + offset * 8);
+ writel_relaxed(value, chip->base + GPIO_DOUT_X_REG + offset * 8);
+ raw_spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static int starfive_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ return readl_relaxed(chip->base + GPIO_DOEN_X_REG + offset * 8) & 0x1;
+}
+
+static int starfive_get_value(struct gpio_chip *gc, unsigned int offset)
+{
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ int value;
+
+ if (offset >= gc->ngpio)
+ return -EINVAL;
+
+ if (offset < 32) {
+ value = readl_relaxed(chip->base + GPIO_DIN_LOW);
+ value = (value >> offset) & 0x1;
+ } else {
+ value = readl_relaxed(chip->base + GPIO_DIN_HIGH);
+ value = (value >> (offset - 32)) & 0x1;
+ }
+
+ return value;
+}
+
+static void starfive_set_value(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ if (offset >= gc->ngpio)
+ return;
+
+ raw_spin_lock_irqsave(&chip->lock, flags);
+ writel_relaxed(value, chip->base + GPIO_DOUT_X_REG + offset * 8);
+ raw_spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static void starfive_set_ie(struct starfive_gpio *chip, int offset)
+{
+ unsigned long flags;
+ int old_value, new_value;
+ int reg_offset, index;
+
+ if (offset < 32) {
+ reg_offset = 0;
+ index = offset;
+ } else {
+ reg_offset = 4;
+ index = offset - 32;
+ }
+ raw_spin_lock_irqsave(&chip->lock, flags);
+ old_value = readl_relaxed(chip->base + GPIO_IE_LOW + reg_offset);
+ new_value = old_value | (1 << index);
+ writel_relaxed(new_value, chip->base + GPIO_IE_LOW + reg_offset);
+ raw_spin_unlock_irqrestore(&chip->lock, flags);
+}
+
+static int starfive_irq_set_type(struct irq_data *d, unsigned int trigger)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(d);
+ unsigned int reg_is, reg_ibe, reg_iev;
+ int reg_offset, index;
+
+ if (offset < 0 || offset >= gc->ngpio)
+ return -EINVAL;
+
+ if (offset < 32) {
+ reg_offset = 0;
+ index = offset;
+ } else {
+ reg_offset = 4;
+ index = offset - 32;
+ }
+
+ reg_is = readl_relaxed(chip->base + GPIO_IS_LOW + reg_offset);
+ reg_ibe = readl_relaxed(chip->base + GPIO_IBE_LOW + reg_offset);
+ reg_iev = readl_relaxed(chip->base + GPIO_IEV_LOW + reg_offset);
+
+ switch (trigger) {
+ case IRQ_TYPE_LEVEL_HIGH:
+ reg_is &= ~(1 << index);
+ reg_ibe &= ~(1 << index);
+ reg_iev |= (1 << index);
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ reg_is &= ~(1 << index);
+ reg_ibe &= ~(1 << index);
+ reg_iev &= (1 << index);
+ break;
+ case IRQ_TYPE_EDGE_BOTH:
+ reg_is |= ~(1 << index);
+ reg_ibe |= ~(1 << index);
+ // no need to set edge type when both
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ reg_is |= ~(1 << index);
+ reg_ibe &= ~(1 << index);
+ reg_iev |= (1 << index);
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ reg_is |= ~(1 << index);
+ reg_ibe &= ~(1 << index);
+ reg_iev &= (1 << index);
+ break;
+ }
+
+ writel_relaxed(reg_is, chip->base + GPIO_IS_LOW + reg_offset);
+ writel_relaxed(reg_ibe, chip->base + GPIO_IBE_LOW + reg_offset);
+ writel_relaxed(reg_iev, chip->base + GPIO_IEV_LOW + reg_offset);
+ chip->trigger[offset] = trigger;
+ starfive_set_ie(chip, offset);
+ return 0;
+}
+
+/* chained_irq_{enter,exit} already mask the parent */
+static void starfive_irq_mask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ unsigned int value;
+ int offset = irqd_to_hwirq(d);
+ int reg_offset, index;
+
+ if (offset < 0 || offset >= gc->ngpio)
+ return;
+
+ if (offset < 32) {
+ reg_offset = 0;
+ index = offset;
+ } else {
+ reg_offset = 4;
+ index = offset - 32;
+ }
+
+ value = readl_relaxed(chip->base + GPIO_IE_LOW + reg_offset);
+ value &= ~(0x1 << index);
+ writel_relaxed(value, chip->base + GPIO_IE_LOW + reg_offset);
+}
+
+static void starfive_irq_unmask(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ unsigned int value;
+ int offset = irqd_to_hwirq(d);
+ int reg_offset, index;
+
+ if (offset < 0 || offset >= gc->ngpio)
+ return;
+
+ if (offset < 32) {
+ reg_offset = 0;
+ index = offset;
+ } else {
+ reg_offset = 4;
+ index = offset - 32;
+ }
+
+ value = readl_relaxed(chip->base + GPIO_IE_LOW + reg_offset);
+ value |= (0x1 << index);
+ writel_relaxed(value, chip->base + GPIO_IE_LOW + reg_offset);
+}
+
+static void starfive_irq_enable(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(d);
+
+ starfive_irq_unmask(d);
+ assign_bit(offset, &chip->enabled, 1);
+}
+
+static void starfive_irq_disable(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct starfive_gpio *chip = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(d) % MAX_GPIO; // must not fail
+
+ assign_bit(offset, &chip->enabled, 0);
+ starfive_set_ie(chip, offset);
+}
+
+static struct irq_chip starfive_irqchip = {
+ .name = "starfive-jh7100-gpio",
+ .irq_set_type = starfive_irq_set_type,
+ .irq_mask = starfive_irq_mask,
+ .irq_unmask = starfive_irq_unmask,
+ .irq_enable = starfive_irq_enable,
+ .irq_disable = starfive_irq_disable,
+};
+
+static irqreturn_t starfive_irq_handler(int irq, void *gc)
+{
+ int offset;
+ int reg_offset, index;
+ unsigned int value;
+ unsigned long flags;
+ struct starfive_gpio *chip = gc;
+
+ for (offset = 0; offset < MAX_GPIO; offset++) {
+ if (offset < 32) {
+ reg_offset = 0;
+ index = offset;
+ } else {
+ reg_offset = 4;
+ index = offset - 32;
+ }
+
+ raw_spin_lock_irqsave(&chip->lock, flags);
+ value = readl_relaxed(chip->base + GPIO_MIS_LOW + reg_offset);
+ if (value & BIT(index))
+ writel_relaxed(BIT(index), chip->base + GPIO_IC_LOW +
+ reg_offset);
+ raw_spin_unlock_irqrestore(&chip->lock, flags);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int starfive_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct starfive_gpio *chip;
+ struct gpio_irq_chip *girq;
+ struct resource *res;
+ int irq, ret, ngpio;
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ chip->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(chip->base)) {
+ dev_err(dev, "failed to allocate device memory\n");
+ return PTR_ERR(chip->base);
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(dev, "Cannot get IRQ resource\n");
+ return irq;
+ }
+
+ raw_spin_lock_init(&chip->lock);
+ chip->gc.direction_input = starfive_direction_input;
+ chip->gc.direction_output = starfive_direction_output;
+ chip->gc.get_direction = starfive_get_direction;
+ chip->gc.get = starfive_get_value;
+ chip->gc.set = starfive_set_value;
+ chip->gc.base = 0;
+ chip->gc.ngpio = MAX_GPIO;
+ chip->gc.label = dev_name(dev);
+ chip->gc.parent = dev;
+ chip->gc.owner = THIS_MODULE;
+
+ girq = &chip->gc.irq;
+ girq->chip = &starfive_irqchip;
+ girq->parent_handler = NULL;
+ girq->num_parents = 0;
+ girq->parents = NULL;
+ girq->default_type = IRQ_TYPE_NONE;
+ girq->handler = handle_simple_irq;
+
+ ret = gpiochip_add_data(&chip->gc, chip);
+ if (ret) {
+ dev_err(dev, "gpiochip_add_data ret=%d!\n", ret);
+ return ret;
+ }
+
+ /* Disable all GPIO interrupts before enabling parent interrupts */
+ iowrite32(0, chip->base + GPIO_IE_HIGH);
+ iowrite32(0, chip->base + GPIO_IE_LOW);
+ chip->enabled = 0;
+
+ ret = devm_request_irq(dev, irq, starfive_irq_handler, IRQF_SHARED,
+ dev_name(dev), chip);
+ if (ret) {
+ dev_err(dev, "IRQ handler registering failed (%d)\n", ret);
+ return ret;
+ }
+
+ writel_relaxed(1, chip->base + GPIO_EN);
+
+ dev_info(dev, "StarFive GPIO chip registered %d GPIOs\n", ngpio);
+
+ return 0;
+}
+
+static const struct of_device_id starfive_gpio_match[] = {
+ { .compatible = "starfive,jh7100-gpio", },
+ { },
+};
+
+static struct platform_driver starfive_gpio_driver = {
+ .probe = starfive_gpio_probe,
+ .driver = {
+ .name = "gpio_starfive_jh7100",
+ .of_match_table = of_match_ptr(starfive_gpio_match),
+ },
+};
+
+static int __init starfive_gpio_init(void)
+{
+ return platform_driver_register(&starfive_gpio_driver);
+}
+subsys_initcall(starfive_gpio_init);
+
+static void __exit starfive_gpio_exit(void)
+{
+ platform_driver_unregister(&starfive_gpio_driver);
+}
+module_exit(starfive_gpio_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Huan Feng <huan.feng@xxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("StarFive JH7100 GPIO driver");
--
2.27.0