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Message-ID: <20151006000841.GA20844@sophia>
Date: Mon, 5 Oct 2015 20:08:41 -0400
From: William Breathitt Gray <vilhelm.gray@...il.com>
To: linus.walleij@...aro.org, gnurou@...il.com
Cc: bhelgaas@...gle.com, linux-kernel@...r.kernel.org,
linux-gpio@...r.kernel.org
Subject: [PATCH v3] gpio: Add GPIO support for the ACCES 104-IDIO-16
The ACCES 104-IDIO-16 family of PC/104 utility boards feature 16
optically isolated inputs and 16 optically isolated FET solid state
outputs. This driver provides GPIO support for these 32 channels of
digital I/O. Change-of-State detection interrupts are not supported.
GPIO 0-15 correspond to digital outputs 0-15, while GPIO 16-31
correspond to digital inputs 0-15.
Signed-off-by: William Breathitt Gray <vilhelm.gray@...il.com>
---
Changes in v3:
- Replace gpio.h include with gpio/driver.h since all needed
relevant symbols and resources are within the latter
- Rename struct a_104_idio_16 'data' member to the more apt and
descriptive 'out_state'
- Add kerneldoc for struct a_104_idio_16_gpio
- Reorganize function definitions to eliminate need for forward
declarations
drivers/gpio/Kconfig | 15 ++++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-104-idio-16.c | 154 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 170 insertions(+)
create mode 100644 drivers/gpio/gpio-104-idio-16.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8949b3f..70b63f1 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -684,6 +684,21 @@ config GPIO_SX150X
endmenu
+menu "ISA GPIO expanders"
+
+menuconfig GPIO_104_IDIO_16
+ tristate "ACCES 104-IDIO-16 GPIO support"
+ depends on X86
+ help
+ Enables GPIO support for the ACCES 104-IDIO-16 family.
+
+config 104_IDIO_16_BASE
+ hex "ACCES 104-IDIO-16 base address"
+ depends on GPIO_104_IDIO_16
+ default 0x000
+
+endmenu
+
menu "MFD GPIO expanders"
config GPIO_ADP5520
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f79a7c4..6f2fea5 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
# Device drivers. Generally keep list sorted alphabetically
obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o
+obj-$(CONFIG_GPIO_104_IDIO_16) += gpio-104-idio-16.o
obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o
obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o
obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
new file mode 100644
index 0000000..f6b2afd
--- /dev/null
+++ b/drivers/gpio/gpio-104-idio-16.c
@@ -0,0 +1,154 @@
+/*
+ * GPIO driver for the ACCES 104-IDIO-16 family
+ * Copyright (C) 2015 William Breathitt Gray
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/spinlock.h>
+
+/**
+ * struct a_104_idio_16_gpio - gpio device private data structure
+ * @chip: instance of the gpio_chip
+ * @lock: synchronization lock to prevent gpio_set race conditions
+ * @base: base port address of the GPIO device
+ * @out_state: output bits state
+ */
+struct a_104_idio_16_gpio {
+ struct gpio_chip chip;
+ spinlock_t lock;
+ unsigned base;
+ unsigned out_state;
+};
+
+static const unsigned A_104_IDIO_16_EXTENT = 8;
+
+static int a_104_idio_16_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ return 0;
+}
+
+static int a_104_idio_16_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ chip->set(chip, offset, value);
+ return 0;
+}
+
+static struct a_104_idio_16_gpio *to_a104i16gp(struct gpio_chip *gc)
+{
+ return container_of(gc, struct a_104_idio_16_gpio, chip);
+}
+
+static int a_104_idio_16_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct a_104_idio_16_gpio *a104i16gp = to_a104i16gp(chip);
+ const unsigned BIT_MASK = 1U << (offset-16);
+
+ if (offset < 16)
+ return 0;
+
+ if (offset < 24)
+ return !!(inb(a104i16gp->base + 1) & BIT_MASK);
+
+ return !!(inb(a104i16gp->base + 5) & (BIT_MASK>>8));
+}
+
+static void a_104_idio_16_gpio_set(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct a_104_idio_16_gpio *a104i16gp = to_a104i16gp(chip);
+ const unsigned BIT_MASK = 1U << offset;
+ unsigned long flags;
+
+ if (offset > 15)
+ return;
+
+ spin_lock_irqsave(&a104i16gp->lock, flags);
+
+ if (value)
+ a104i16gp->out_state |= BIT_MASK;
+ else
+ a104i16gp->out_state &= ~BIT_MASK;
+
+ if (offset > 7)
+ outb(~a104i16gp->out_state >> 8, a104i16gp->base + 4);
+ else
+ outb(~a104i16gp->out_state, a104i16gp->base);
+
+ spin_unlock_irqrestore(&a104i16gp->lock, flags);
+}
+
+static struct a_104_idio_16_gpio gp = {
+ .chip = {
+ .label = "104-IDIO-16 GPIO",
+ .owner = THIS_MODULE,
+ .base = -1,
+ .ngpio = 32,
+ .direction_input = a_104_idio_16_gpio_direction_input,
+ .direction_output = a_104_idio_16_gpio_direction_output,
+ .get = a_104_idio_16_gpio_get,
+ .set = a_104_idio_16_gpio_set
+ },
+ .base = CONFIG_104_IDIO_16_BASE
+};
+
+static void __exit a_104_idio_16_exit(void)
+{
+ pr_info("104-idio-16: Exiting 104-idio-16 module\n");
+
+ gpiochip_remove(&gp.chip);
+ release_region(CONFIG_104_IDIO_16_BASE, A_104_IDIO_16_EXTENT);
+}
+
+static int __init a_104_idio_16_init(void)
+{
+ int err = 0;
+
+ pr_info("104-idio-16: Initializing 104-idio-16 module\n");
+
+ if (!request_region(CONFIG_104_IDIO_16_BASE, A_104_IDIO_16_EXTENT,
+ "104-idio-16")) {
+ pr_err("104-idio-16: Unable to lock 104-idio-16 port addresses (0x%X-0x%X)\n",
+ CONFIG_104_IDIO_16_BASE,
+ CONFIG_104_IDIO_16_BASE + A_104_IDIO_16_EXTENT);
+ err = -EBUSY;
+ goto out_lock_a_104_idio_16_port;
+ }
+
+ spin_lock_init(&gp.lock);
+
+ pr_info("104-idio-16: 104-IDIO-16 GPIO detected\n");
+ err = gpiochip_add(&gp.chip);
+ if (err) {
+ pr_err("104-idio-16: GPIO registering failed (%d)\n", err);
+ goto out_gpio_register;
+ }
+
+ return 0;
+
+out_gpio_register:
+ release_region(CONFIG_104_IDIO_16_BASE, A_104_IDIO_16_EXTENT);
+out_lock_a_104_idio_16_port:
+ return err;
+}
+
+module_init(a_104_idio_16_init);
+module_exit(a_104_idio_16_exit);
+
+MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@...il.com>");
+MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
+MODULE_LICENSE("GPL");
--
2.4.9
--
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