v4.19.13 snapshot.
diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
new file mode 100644
index 0000000..0ecd236
--- /dev/null
+++ b/drivers/gpio/gpio-exar.c
@@ -0,0 +1,204 @@
+/*
+ * GPIO driver for Exar XR17V35X chip
+ *
+ * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#define EXAR_OFFSET_MPIOLVL_LO 0x90
+#define EXAR_OFFSET_MPIOSEL_LO 0x93
+#define EXAR_OFFSET_MPIOLVL_HI 0x96
+#define EXAR_OFFSET_MPIOSEL_HI 0x99
+
+#define DRIVER_NAME "gpio_exar"
+
+static DEFINE_IDA(ida_index);
+
+struct exar_gpio_chip {
+ struct gpio_chip gpio_chip;
+ struct mutex lock;
+ int index;
+ void __iomem *regs;
+ char name[20];
+ unsigned int first_pin;
+};
+
+static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
+ unsigned int offset)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ int temp;
+
+ mutex_lock(&exar_gpio->lock);
+ temp = readb(exar_gpio->regs + reg);
+ temp &= ~BIT(offset);
+ if (val)
+ temp |= BIT(offset);
+ writeb(temp, exar_gpio->regs + reg);
+ mutex_unlock(&exar_gpio->lock);
+}
+
+static int exar_set_direction(struct gpio_chip *chip, int direction,
+ unsigned int offset)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+ EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+ unsigned int bit = (offset + exar_gpio->first_pin) % 8;
+
+ exar_update(chip, addr, direction, bit);
+ return 0;
+}
+
+static int exar_get(struct gpio_chip *chip, unsigned int reg)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ int value;
+
+ mutex_lock(&exar_gpio->lock);
+ value = readb(exar_gpio->regs + reg);
+ mutex_unlock(&exar_gpio->lock);
+
+ return value;
+}
+
+static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+ EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
+ unsigned int bit = (offset + exar_gpio->first_pin) % 8;
+
+ return !!(exar_get(chip, addr) & BIT(bit));
+}
+
+static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+ EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+ unsigned int bit = (offset + exar_gpio->first_pin) % 8;
+
+ return !!(exar_get(chip, addr) & BIT(bit));
+}
+
+static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
+ unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
+ EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
+ unsigned int bit = (offset + exar_gpio->first_pin) % 8;
+
+ exar_update(chip, addr, value, bit);
+}
+
+static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ exar_set_value(chip, offset, value);
+ return exar_set_direction(chip, 0, offset);
+}
+
+static int exar_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+ return exar_set_direction(chip, 1, offset);
+}
+
+static int gpio_exar_probe(struct platform_device *pdev)
+{
+ struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
+ struct exar_gpio_chip *exar_gpio;
+ u32 first_pin, ngpios;
+ void __iomem *p;
+ int index, ret;
+
+ /*
+ * The UART driver must have mapped region 0 prior to registering this
+ * device - use it.
+ */
+ p = pcim_iomap_table(pcidev)[0];
+ if (!p)
+ return -ENOMEM;
+
+ ret = device_property_read_u32(&pdev->dev, "exar,first-pin",
+ &first_pin);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios);
+ if (ret)
+ return ret;
+
+ exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
+ if (!exar_gpio)
+ return -ENOMEM;
+
+ mutex_init(&exar_gpio->lock);
+
+ index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
+
+ sprintf(exar_gpio->name, "exar_gpio%d", index);
+ exar_gpio->gpio_chip.label = exar_gpio->name;
+ exar_gpio->gpio_chip.parent = &pdev->dev;
+ exar_gpio->gpio_chip.direction_output = exar_direction_output;
+ exar_gpio->gpio_chip.direction_input = exar_direction_input;
+ exar_gpio->gpio_chip.get_direction = exar_get_direction;
+ exar_gpio->gpio_chip.get = exar_get_value;
+ exar_gpio->gpio_chip.set = exar_set_value;
+ exar_gpio->gpio_chip.base = -1;
+ exar_gpio->gpio_chip.ngpio = ngpios;
+ exar_gpio->regs = p;
+ exar_gpio->index = index;
+ exar_gpio->first_pin = first_pin;
+
+ ret = devm_gpiochip_add_data(&pdev->dev,
+ &exar_gpio->gpio_chip, exar_gpio);
+ if (ret)
+ goto err_destroy;
+
+ platform_set_drvdata(pdev, exar_gpio);
+
+ return 0;
+
+err_destroy:
+ ida_simple_remove(&ida_index, index);
+ mutex_destroy(&exar_gpio->lock);
+ return ret;
+}
+
+static int gpio_exar_remove(struct platform_device *pdev)
+{
+ struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev);
+
+ ida_simple_remove(&ida_index, exar_gpio->index);
+ mutex_destroy(&exar_gpio->lock);
+
+ return 0;
+}
+
+static struct platform_driver gpio_exar_driver = {
+ .probe = gpio_exar_probe,
+ .remove = gpio_exar_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+};
+
+module_platform_driver(gpio_exar_driver);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_DESCRIPTION("Exar GPIO driver");
+MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>");
+MODULE_LICENSE("GPL");