[PATCH 07/10] gpio: 104-dio-48e: Utilize the ISA bus driver

From: William Breathitt Gray
Date: Thu Apr 07 2016 - 10:48:58 EST


The ACCES 104-DIO-48E series communicates via the ISA bus. As such, it
is more appropriate to use the ISA bus driver over the platform driver
to control the ACCES 104-DIO-48E GPIO driver.

This patch also adds support for multiple devices via the base and irq
module array parameters. Each element of the base array corresponds to a
discrete device; each element of the irq array corresponds to the
respective device addressed in the respective base array element.

Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
---
drivers/gpio/Kconfig | 9 ++--
drivers/gpio/gpio-104-dio-48e.c | 106 ++++++++++++++--------------------------
2 files changed, 43 insertions(+), 72 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 5f3429f..4ce3f8d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -517,12 +517,13 @@ menu "Port-mapped I/O GPIO drivers"

config GPIO_104_DIO_48E
tristate "ACCES 104-DIO-48E GPIO support"
+ depends on ISA_BUS
select GPIOLIB_IRQCHIP
help
- Enables GPIO support for the ACCES 104-DIO-48E family. The base port
- address for the device may be configured via the dio_48e_base module
- parameter. The interrupt line number for the device may be configured
- via the dio_48e_irq module parameter.
+ Enables GPIO support for the ACCES 104-DIO-48E series (104-DIO-48E,
+ 104-DIO-24E). The base port addresses for the devices may be
+ configured via the base module parameter. The interrupt line numbers
+ for the devices may be configured via the irq module parameter.

config GPIO_104_IDIO_16
tristate "ACCES 104-IDIO-16 GPIO support"
diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c
index 448a903..1a647c0 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -1,5 +1,5 @@
/*
- * GPIO driver for the ACCES 104-DIO-48E
+ * GPIO driver for the ACCES 104-DIO-48E series
* Copyright (C) 2016 William Breathitt Gray
*
* This program is free software; you can redistribute it and/or modify
@@ -10,6 +10,9 @@
* 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.
+ *
+ * This driver supports the following ACCES devices: 104-DIO-48E and
+ * 104-DIO-24E.
*/
#include <linux/bitops.h>
#include <linux/device.h>
@@ -19,18 +22,23 @@
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/irqdesc.h>
+#include <linux/isa.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
-#include <linux/platform_device.h>
#include <linux/spinlock.h>

-static unsigned dio_48e_base;
-module_param(dio_48e_base, uint, 0);
-MODULE_PARM_DESC(dio_48e_base, "ACCES 104-DIO-48E base address");
-static unsigned dio_48e_irq;
-module_param(dio_48e_irq, uint, 0);
-MODULE_PARM_DESC(dio_48e_irq, "ACCES 104-DIO-48E interrupt line number");
+#define DIO48E_EXTENT 16
+#define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
+
+static unsigned int base[MAX_NUM_DIO48E];
+static unsigned int num_dio48e;
+module_param_array(base, uint, &num_dio48e, 0);
+MODULE_PARM_DESC(base, "ACCES 104-DIO-48E base addresses");
+
+static unsigned int irq[MAX_NUM_DIO48E];
+module_param_array(irq, uint, NULL, 0);
+MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");

/**
* struct dio48e_gpio - GPIO device private data structure
@@ -294,23 +302,19 @@ static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static int __init dio48e_probe(struct platform_device *pdev)
+static int dio48e_probe(struct device *dev, unsigned int id)
{
- struct device *dev = &pdev->dev;
struct dio48e_gpio *dio48egpio;
- const unsigned base = dio_48e_base;
- const unsigned extent = 16;
const char *const name = dev_name(dev);
int err;
- const unsigned irq = dio_48e_irq;

dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL);
if (!dio48egpio)
return -ENOMEM;

- if (!devm_request_region(dev, base, extent, name)) {
+ if (!devm_request_region(dev, base[id], DIO48E_EXTENT, name)) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
- base, base + extent);
+ base[id], base[id] + DIO48E_EXTENT);
return -EBUSY;
}

@@ -324,8 +328,8 @@ static int __init dio48e_probe(struct platform_device *pdev)
dio48egpio->chip.direction_output = dio48e_gpio_direction_output;
dio48egpio->chip.get = dio48e_gpio_get;
dio48egpio->chip.set = dio48e_gpio_set;
- dio48egpio->base = base;
- dio48egpio->irq = irq;
+ dio48egpio->base = base[id];
+ dio48egpio->irq = irq[id];

spin_lock_init(&dio48egpio->lock);

@@ -338,19 +342,19 @@ static int __init dio48e_probe(struct platform_device *pdev)
}

/* initialize all GPIO as output */
- outb(0x80, base + 3);
- outb(0x00, base);
- outb(0x00, base + 1);
- outb(0x00, base + 2);
- outb(0x00, base + 3);
- outb(0x80, base + 7);
- outb(0x00, base + 4);
- outb(0x00, base + 5);
- outb(0x00, base + 6);
- outb(0x00, base + 7);
+ outb(0x80, base[id] + 3);
+ outb(0x00, base[id]);
+ outb(0x00, base[id] + 1);
+ outb(0x00, base[id] + 2);
+ outb(0x00, base[id] + 3);
+ outb(0x80, base[id] + 7);
+ outb(0x00, base[id] + 4);
+ outb(0x00, base[id] + 5);
+ outb(0x00, base[id] + 6);
+ outb(0x00, base[id] + 7);

/* disable IRQ by default */
- inb(base + 0xB);
+ inb(base[id] + 0xB);

err = gpiochip_irqchip_add(&dio48egpio->chip, &dio48e_irqchip, 0,
handle_edge_irq, IRQ_TYPE_NONE);
@@ -359,7 +363,7 @@ static int __init dio48e_probe(struct platform_device *pdev)
goto err_gpiochip_remove;
}

- err = request_irq(irq, dio48e_irq_handler, 0, name, dio48egpio);
+ err = request_irq(irq[id], dio48e_irq_handler, 0, name, dio48egpio);
if (err) {
dev_err(dev, "IRQ handler registering failed (%d)\n", err);
goto err_gpiochip_remove;
@@ -372,9 +376,9 @@ err_gpiochip_remove:
return err;
}

-static int dio48e_remove(struct platform_device *pdev)
+static int dio48e_remove(struct device *dev, unsigned int id)
{
- struct dio48e_gpio *const dio48egpio = platform_get_drvdata(pdev);
+ struct dio48e_gpio *const dio48egpio = dev_get_drvdata(dev);

free_irq(dio48egpio->irq, dio48egpio);
gpiochip_remove(&dio48egpio->chip);
@@ -382,48 +386,14 @@ static int dio48e_remove(struct platform_device *pdev)
return 0;
}

-static struct platform_device *dio48e_device;
-
-static struct platform_driver dio48e_driver = {
+static struct isa_driver dio48e_driver = {
+ .probe = dio48e_probe,
.driver = {
.name = "104-dio-48e"
},
.remove = dio48e_remove
};
-
-static void __exit dio48e_exit(void)
-{
- platform_device_unregister(dio48e_device);
- platform_driver_unregister(&dio48e_driver);
-}
-
-static int __init dio48e_init(void)
-{
- int err;
-
- dio48e_device = platform_device_alloc(dio48e_driver.driver.name, -1);
- if (!dio48e_device)
- return -ENOMEM;
-
- err = platform_device_add(dio48e_device);
- if (err)
- goto err_platform_device;
-
- err = platform_driver_probe(&dio48e_driver, dio48e_probe);
- if (err)
- goto err_platform_driver;
-
- return 0;
-
-err_platform_driver:
- platform_device_del(dio48e_device);
-err_platform_device:
- platform_device_put(dio48e_device);
- return err;
-}
-
-module_init(dio48e_init);
-module_exit(dio48e_exit);
+module_isa_driver(dio48e_driver, num_dio48e);

MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@xxxxxxxxx>");
MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver");
--
2.7.3