Exar XR17V352/354/358 chips have 16 multi-purpose inputs/outputs which
can be controlled using gpio interface.
Add the gpio specific code.
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
---
drivers/gpio/Kconfig | 7 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-exar.c | 238 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 246 insertions(+)
create mode 100644 drivers/gpio/gpio-exar.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ed37e59..89033d6 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -185,6 +185,13 @@ config GPIO_ETRAXFS
help
Say yes here to support the GPIO controller on Axis ETRAX FS SoCs.
+config GPIO_EXAR
+ tristate "Support for GPIO pins on XR17V352/354/358"
+ depends on SERIAL_8250_EXAR
+ help
+ Selecting this option will enable handling of GPIO pins present
+ on Exar XR17V352/354/358 chips.
+
config GPIO_GE_FPGA
bool "GE FPGA based GPIO"
depends on GE_FPGA
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d074c22..d4d44f8 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
obj-$(CONFIG_GPIO_EM) += gpio-em.o
obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_ETRAXFS) += gpio-etraxfs.o
+obj-$(CONFIG_GPIO_EXAR) += gpio-exar.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o
diff --git a/drivers/gpio/gpio-exar.c b/drivers/gpio/gpio-exar.c
new file mode 100644
index 0000000..b7d1363
--- /dev/null
+++ b/drivers/gpio/gpio-exar.c
@@ -0,0 +1,238 @@
+/*
+ * GPIO driver for Exar XR17V35X chip
+ *
+ * Copyright (C) 2015 Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/device.h>
+#include <linux/gpio.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 LIST_HEAD(exar_list);
+static DEFINE_MUTEX(exar_list_mtx);
+DEFINE_IDA(ida_index);
+
+struct exar_gpio_chip {
+ struct gpio_chip gpio_chip;
+ struct pci_dev *pcidev;
+ struct mutex lock;
+ struct list_head list;
+ int index;
+ void __iomem *regs;
+ char name[16];
+};
+
+#define to_exar_chip(n) container_of(n, struct exar_gpio_chip, gpio_chip)
+
+static inline unsigned int read_exar_reg(struct exar_gpio_chip *chip,
+ int offset)
+{
+ dev_dbg(chip->gpio_chip.parent, "regs=%p offset=%x\n",
+ chip->regs, offset);
+
+ return readb(chip->regs + offset);
+}
+
+static inline void write_exar_reg(struct exar_gpio_chip *chip, int offset,
+ int value)
+{
+ dev_dbg(chip->gpio_chip.parent,
+ "regs=%p value=%x offset=%x\n", chip->regs, value,
+ offset);
+ writeb(value, chip->regs + offset);
+}
+
+static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
+ unsigned int offset)
+{
+ struct exar_gpio_chip *exar_gpio = to_exar_chip(chip);
+ int temp;
+
+ mutex_lock(&exar_gpio->lock);
+ temp = read_exar_reg(exar_gpio, reg);
+ temp &= ~(1 << offset);
+ temp |= val << offset;
+ write_exar_reg(exar_gpio, reg, temp);
+ mutex_unlock(&exar_gpio->lock);
+}
+
+static int exar_set_direction(struct gpio_chip *chip, int direction,
+ unsigned int offset)
+{
+ if (offset < 8)
+ exar_update(chip, EXAR_OFFSET_MPIOSEL_LO, direction,
+ offset);
+ else
+ exar_update(chip, EXAR_OFFSET_MPIOSEL_HI, direction,
+ offset - 8);
+ return 0;
+}
+
+static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
+ int 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 exar_get(struct gpio_chip *chip, unsigned int reg)
+{
+ struct exar_gpio_chip *exar_gpio = to_exar_chip(chip);
+ int value;
+
+ mutex_lock(&exar_gpio->lock);
+ value = read_exar_reg(exar_gpio, reg);
+ mutex_unlock(&exar_gpio->lock);
+
+ return value;
+}
+
+static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+ int val;
+
+ if (offset < 8)
+ val = exar_get(chip, EXAR_OFFSET_MPIOSEL_LO) >> offset;
+ else
+ val = exar_get(chip, EXAR_OFFSET_MPIOSEL_HI) >>
+ (offset - 8);
+
+ return val & 0x01;
+}
+
+static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
+{
+ int val;
+
+ if (offset < 8)
+ val = exar_get(chip, EXAR_OFFSET_MPIOLVL_LO) >> offset;
+ else
+ val = exar_get(chip, EXAR_OFFSET_MPIOLVL_HI) >>
+ (offset - 8);
+ return val & 0x01;
+}
+
+static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ if (offset < 8)
+ exar_update(chip, EXAR_OFFSET_MPIOLVL_LO, value,
+ offset);
+ else
+ exar_update(chip, EXAR_OFFSET_MPIOLVL_HI, value,
+ offset - 8);
+}
+
+static int gpio_exar_probe(struct platform_device *pdev)
+{
+ struct pci_dev *dev = platform_get_drvdata(pdev);
+ struct exar_gpio_chip *exar_gpio;
+ void __iomem *p;
+ int index = 1;
+ int ret;
+
+ if (dev->vendor != PCI_VENDOR_ID_EXAR)
+ return -ENODEV;
+
+ p = pci_ioremap_bar(dev, 0);
+ if (!p)
+ return -ENOMEM;
+
+ exar_gpio = devm_kzalloc(&dev->dev, sizeof(*exar_gpio), GFP_KERNEL);
+ if (!exar_gpio)
+ return -ENOMEM;
+
+ mutex_init(&exar_gpio->lock);
+ INIT_LIST_HEAD(&exar_gpio->list);
+
+ index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
+ mutex_lock(&exar_list_mtx);
+
+ sprintf(exar_gpio->name, "exar_gpio%d", index);
+ exar_gpio->gpio_chip.label = exar_gpio->name;
+ exar_gpio->gpio_chip.parent = &dev->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 = 16;
+ exar_gpio->regs = p;
+ exar_gpio->index = index;
+ exar_gpio->pcidev = dev;
+
+ ret = gpiochip_add(&exar_gpio->gpio_chip);
+ if (ret)
+ goto err_destroy;
+
+ list_add_tail(&exar_gpio->list, &exar_list);
+ mutex_unlock(&exar_list_mtx);
+
+ return 0;
+
+err_destroy:
+ mutex_unlock(&exar_list_mtx);
+ mutex_destroy(&exar_gpio->lock);
+ return ret;
+}
+
+static int gpio_exar_remove(struct platform_device *pdev)
+{
+ struct exar_gpio_chip *exar_gpio, *exar_temp;
+ struct pci_dev *pcidev;
+ int index;
+
+ pcidev = platform_get_drvdata(pdev);
+
+ mutex_lock(&exar_list_mtx);
+ list_for_each_entry_safe(exar_gpio, exar_temp, &exar_list, list) {
+ if (exar_gpio->pcidev == pcidev) {
+ list_del(&exar_gpio->list);
+ break;
+ }
+ }
+ mutex_unlock(&exar_list_mtx);
+
+ index = exar_gpio->index;
+ gpiochip_remove(&exar_gpio->gpio_chip);
+ mutex_destroy(&exar_gpio->lock);
+ ida_simple_remove(&ida_index, index);
+
+ 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 <sudipm.mukherjee@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
--
1.9.1
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