This driver supports the Chip Common A GPIO controller present on a
number of Broadcom switch ASICs with integrated SoCs. The controller is
similar to the pinctrl-nsp-gpio and pinctrl-iproc-gpio blocks but
different enough that a separate driver is required.

This has been ported from Broadcom's XLDK 5.0.3 retaining only the CCA
support (pinctrl-iproc-gpio covers CCB).

Signed-off-by: Chris Packham <chris.pack...@alliedtelesis.co.nz>
---

Notes:
    Changes in v2:
    - use more of the generic infrastructure for gpio chips
    - handling the root interrupt is still done manually due to sharing with 
uart0.

 drivers/gpio/Kconfig          |   9 +
 drivers/gpio/Makefile         |   1 +
 drivers/gpio/gpio-xgs-iproc.c | 301 ++++++++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+)
 create mode 100644 drivers/gpio/gpio-xgs-iproc.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 38e096e6925f..4b3c0f8397d7 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -156,6 +156,15 @@ config GPIO_BRCMSTB
        help
          Say yes here to enable GPIO support for Broadcom STB (BCM7XXX) SoCs.
 
+config GPIO_XGS_IPROC
+       tristate "BRCM XGS iProc GPIO support"
+       depends on OF_GPIO && (ARCH_BCM_IPROC || COMPILE_TEST)
+       select GPIO_GENERIC
+       select GPIOLIB_IRQCHIP
+       default ARCH_BCM_IPROC
+       help
+         Say yes here to enable GPIO support for Broadcom XGS iProc SoCs.
+
 config GPIO_CADENCE
        tristate "Cadence GPIO support"
        depends on OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d2fd19c15bae..3783c3d43fbe 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_GPIO_BCM_KONA)           += gpio-bcm-kona.o
 obj-$(CONFIG_GPIO_BD70528)             += gpio-bd70528.o
 obj-$(CONFIG_GPIO_BD9571MWV)           += gpio-bd9571mwv.o
 obj-$(CONFIG_GPIO_BRCMSTB)             += gpio-brcmstb.o
+obj-$(CONFIG_GPIO_XGS_IPROC)           += gpio-xgs-iproc.o
 obj-$(CONFIG_GPIO_BT8XX)               += gpio-bt8xx.o
 obj-$(CONFIG_GPIO_CADENCE)             += gpio-cadence.o
 obj-$(CONFIG_GPIO_CLPS711X)            += gpio-clps711x.o
diff --git a/drivers/gpio/gpio-xgs-iproc.c b/drivers/gpio/gpio-xgs-iproc.c
new file mode 100644
index 000000000000..a0277acf9369
--- /dev/null
+++ b/drivers/gpio/gpio-xgs-iproc.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Broadcom Corporation
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+
+#define CCA_INT_F_GPIOINT              BIT(0)
+#define CCA_INT_STS                    0x20
+#define CCA_INT_MASK                   0x24
+
+#define GPIO_CCA_DIN                   0x0
+#define GPIO_CCA_DOUT                  0x4
+#define GPIO_CCA_OUT_EN                        0x8
+#define GPIO_CCA_INT_LEVEL             0x10
+#define GPIO_CCA_INT_LEVEL_MASK                0x14
+#define GPIO_CCA_INT_EVENT             0x18
+#define GPIO_CCA_INT_EVENT_MASK                0x1C
+#define GPIO_CCA_INT_EDGE              0x24
+
+struct iproc_gpio_chip {
+       struct irq_chip irqchip;
+       struct gpio_chip gc;
+       spinlock_t lock;
+       struct device *dev;
+       void __iomem *base;
+       void __iomem *intr;
+};
+
+static inline struct iproc_gpio_chip *
+to_iproc_gpio(struct gpio_chip *gc)
+{
+       return container_of(gc, struct iproc_gpio_chip, gc);
+}
+
+static void iproc_gpio_irq_ack(struct irq_data *d)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+       int pin = d->hwirq;
+       u32 irq = d->irq;
+       u32 irq_type, event_status = 0;
+
+       irq_type = irq_get_trigger_type(irq);
+       if (irq_type & IRQ_TYPE_EDGE_BOTH) {
+               event_status |= BIT(pin);
+               writel(event_status, chip->base + GPIO_CCA_INT_EVENT);
+       }
+}
+
+static void iproc_gpio_irq_unmask(struct irq_data *d)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+       int pin = d->hwirq;
+       u32 irq = d->irq;
+       u32 int_mask, irq_type, event_mask;
+
+       irq_type = irq_get_trigger_type(irq);
+       event_mask = readl(chip->base + GPIO_CCA_INT_EVENT_MASK);
+       int_mask = readl(chip->base + GPIO_CCA_INT_LEVEL_MASK);
+
+       if (irq_type & IRQ_TYPE_EDGE_BOTH) {
+               event_mask |= 1 << pin;
+               writel(event_mask, chip->base + GPIO_CCA_INT_EVENT_MASK);
+       } else {
+               int_mask |= 1 << pin;
+               writel(int_mask, chip->base + GPIO_CCA_INT_LEVEL_MASK);
+       }
+}
+
+static void iproc_gpio_irq_mask(struct irq_data *d)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+       int pin = d->hwirq;
+       u32 irq = d->irq;
+       u32 irq_type, int_mask, event_mask;
+
+       irq_type = irq_get_trigger_type(irq);
+       event_mask = readl(chip->base + GPIO_CCA_INT_EVENT_MASK);
+       int_mask = readl(chip->base + GPIO_CCA_INT_LEVEL_MASK);
+
+       if (irq_type & IRQ_TYPE_EDGE_BOTH) {
+               event_mask &= ~BIT(pin);
+               writel(event_mask, chip->base + GPIO_CCA_INT_EVENT_MASK);
+       } else {
+               int_mask &= ~BIT(pin);
+               writel(int_mask, chip->base + GPIO_CCA_INT_LEVEL_MASK);
+       }
+}
+
+
+static int iproc_gpio_irq_set_type(struct irq_data *d, u32 type)
+{
+       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+       struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+       int pin = d->hwirq;
+       u32 irq = d->irq;
+       u32 event_pol, int_pol;
+
+
+       switch (type & IRQ_TYPE_SENSE_MASK) {
+       case IRQ_TYPE_EDGE_RISING:
+               event_pol = readl(chip->base + GPIO_CCA_INT_EDGE);
+               event_pol &= ~BIT(pin);
+               writel(event_pol, chip->base + GPIO_CCA_INT_EDGE);
+               break;
+       case IRQ_TYPE_EDGE_FALLING:
+               event_pol = readl(chip->base + GPIO_CCA_INT_EDGE);
+               event_pol |= BIT(pin);
+               writel(event_pol, chip->base + GPIO_CCA_INT_EDGE);
+               break;
+       case IRQ_TYPE_LEVEL_HIGH:
+               int_pol = readl(chip->base + GPIO_CCA_INT_LEVEL);
+               int_pol &= ~BIT(pin);
+               writel(int_pol, chip->base + GPIO_CCA_INT_LEVEL);
+               break;
+       case IRQ_TYPE_LEVEL_LOW:
+               int_pol = readl(chip->base + GPIO_CCA_INT_LEVEL);
+               int_pol |= BIT(pin);
+               writel(int_pol, chip->base + GPIO_CCA_INT_LEVEL);
+               break;
+       default:
+               /* should not come here */
+               return -EINVAL;
+       }
+
+       if (type & IRQ_TYPE_LEVEL_MASK)
+               irq_set_handler_locked(irq_get_irq_data(irq), handle_level_irq);
+       else if (type & IRQ_TYPE_EDGE_BOTH)
+               irq_set_handler_locked(irq_get_irq_data(irq), handle_edge_irq);
+
+       return 0;
+}
+
+static irqreturn_t iproc_gpio_irq_handler(int irq, void *data)
+{
+       struct gpio_chip *gc = (struct gpio_chip *)data;
+       struct iproc_gpio_chip *chip = to_iproc_gpio(gc);
+       int bit;
+       unsigned long int_bits = 0;
+       u32 int_status;
+
+       /* go through the entire GPIOs and handle all interrupts */
+       int_status = readl(chip->intr + CCA_INT_STS);
+       if (int_status & CCA_INT_F_GPIOINT) {
+               u32 event, level;
+
+               /* Get level and edge interrupts */
+               event = readl(chip->base + GPIO_CCA_INT_EVENT_MASK);
+               event &= readl(chip->base + GPIO_CCA_INT_EVENT);
+               level = readl(chip->base + GPIO_CCA_DIN);
+               level ^= readl(chip->base + GPIO_CCA_INT_LEVEL);
+               level &= readl(chip->base + GPIO_CCA_INT_LEVEL_MASK);
+               int_bits = level | event;
+
+               for_each_set_bit(bit, &int_bits, gc->ngpio)
+                       generic_handle_irq(
+                               irq_linear_revmap(gc->irq.domain, bit));
+       }
+
+       return  int_bits ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int iproc_gpio_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct device_node *dn = pdev->dev.of_node;
+       struct iproc_gpio_chip *chip;
+       u32 num_gpios;
+       int irq, ret;
+
+       chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+       if (!chip)
+               return -ENOMEM;
+
+       chip->dev = dev;
+       platform_set_drvdata(pdev, chip);
+
+       chip->base = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(chip->base))
+               return PTR_ERR(chip->base);
+
+       ret = bgpio_init(&chip->gc, dev, 4,
+                        chip->base + GPIO_CCA_DIN,
+                        chip->base + GPIO_CCA_DOUT,
+                        NULL,
+                        chip->base + GPIO_CCA_OUT_EN,
+                        NULL,
+                        0);
+       if (ret) {
+               dev_err(dev, "unable to init GPIO chip\n");
+               return ret;
+       }
+
+       chip->gc.label = dev_name(dev);
+       if (of_property_read_u32(dn, "ngpios", &num_gpios))
+               chip->gc.ngpio = num_gpios;
+
+       irq = platform_get_irq(pdev, 0);
+       if (irq > 0) {
+               struct gpio_irq_chip *girq;
+               struct irq_chip *irqc;
+               u32 val;
+
+               irqc = &chip->irqchip;
+               irqc->name = dev_name(dev);
+               irqc->irq_ack = iproc_gpio_irq_ack;
+               irqc->irq_mask = iproc_gpio_irq_mask;
+               irqc->irq_unmask = iproc_gpio_irq_unmask;
+               irqc->irq_set_type = iproc_gpio_irq_set_type;
+
+               chip->intr = devm_platform_ioremap_resource(pdev, 1);
+               if (IS_ERR(chip->intr))
+                       return PTR_ERR(chip->intr);
+
+               /* Enable GPIO interrupts for CCA GPIO */
+               val = readl(chip->intr + CCA_INT_MASK);
+               val |= CCA_INT_F_GPIOINT;
+               writel(val, chip->intr + CCA_INT_MASK);
+
+               /*
+                * Directly request the irq here instead of passing
+                * a flow-handler to gpiochip_set_chained_irqchip,
+                * because the irq is shared.
+                */
+               ret = devm_request_irq(dev, irq, iproc_gpio_irq_handler,
+                                      IRQF_SHARED, chip->gc.label, &chip->gc);
+               if (ret) {
+                       dev_err(dev, "Fail to request IRQ%d: %d\n", irq, ret);
+                       return ret;
+               }
+
+               girq = &chip->gc.irq;
+               girq->chip =  irqc;
+               /* This will let us handle the parent IRQ in the driver */
+               girq->parent_handler = NULL;
+               girq->num_parents = 0;
+               girq->parents = NULL;
+               girq->default_type = IRQ_TYPE_NONE;
+               girq->handler = handle_simple_irq;
+       }
+
+       ret = devm_gpiochip_add_data(dev, &chip->gc, chip);
+       if (ret) {
+               dev_err(dev, "unable to add GPIO chip\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int __exit iproc_gpio_remove(struct platform_device *pdev)
+{
+       struct iproc_gpio_chip *chip;
+
+       chip = platform_get_drvdata(pdev);
+       if (!chip)
+               return -ENODEV;
+
+       if (chip->intr) {
+               u32 val;
+
+               val = readl(chip->intr + CCA_INT_MASK);
+               val &= ~CCA_INT_F_GPIOINT;
+               writel(val, chip->intr + CCA_INT_MASK);
+       }
+
+       return 0;
+}
+
+static const struct of_device_id bcm_iproc_gpio_of_match[] __initconst = {
+       { .compatible = "brcm,iproc-gpio-cca" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, bcm_iproc_gpio_of_match);
+
+static struct platform_driver bcm_iproc_gpio_driver = {
+       .driver = {
+               .name = "iproc-xgs-gpio",
+               .owner = THIS_MODULE,
+               .of_match_table = bcm_iproc_gpio_of_match,
+       },
+       .probe = iproc_gpio_probe,
+       .remove = iproc_gpio_remove,
+};
+
+module_platform_driver(bcm_iproc_gpio_driver);
+
+MODULE_DESCRIPTION("XGS IPROC GPIO driver");
+MODULE_LICENSE("GPL v2");
-- 
2.23.0

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