[PATCH 09/10] gpio: 104-idio-16: Utilize the ISA bus driver

From: William Breathitt Gray
Date: Thu Apr 07 2016 - 10:49:12 EST


The ACCES 104-IDIO-16 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-IDIO-16 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 | 10 +++--
drivers/gpio/gpio-104-idio-16.c | 85 ++++++++++++++---------------------------
2 files changed, 34 insertions(+), 61 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 46db6fc..5ee6706 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -527,12 +527,14 @@ config GPIO_104_DIO_48E

config GPIO_104_IDIO_16
tristate "ACCES 104-IDIO-16 GPIO support"
+ depends on ISA_BUS
select GPIOLIB_IRQCHIP
help
- Enables GPIO support for the ACCES 104-IDIO-16 family. The base port
- address for the device may be set via the idio_16_base module
- parameter. The interrupt line number for the device may be set via the
- idio_16_irq module parameter.
+ Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
+ 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, 104-IDO-8). 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_IDI_48
tristate "ACCES 104-IDI-48 GPIO support"
diff --git a/drivers/gpio/gpio-104-idio-16.c b/drivers/gpio/gpio-104-idio-16.c
index ecc85fe..6787b8f 100644
--- a/drivers/gpio/gpio-104-idio-16.c
+++ b/drivers/gpio/gpio-104-idio-16.c
@@ -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-IDIO-16,
+ * 104-IDIO-16E, 104-IDO-16, 104-IDIO-8, 104-IDIO-8E, and 104-IDO-8.
*/
#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 idio_16_base;
-module_param(idio_16_base, uint, 0);
-MODULE_PARM_DESC(idio_16_base, "ACCES 104-IDIO-16 base address");
-static unsigned idio_16_irq;
-module_param(idio_16_irq, uint, 0);
-MODULE_PARM_DESC(idio_16_irq, "ACCES 104-IDIO-16 interrupt line number");
+#define IDIO_16_EXTENT 8
+#define MAX_NUM_IDIO_16 max_num_isa_dev(IDIO_16_EXTENT)
+
+static unsigned int base[MAX_NUM_IDIO_16];
+static unsigned int num_idio_16;
+module_param_array(base, uint, &num_idio_16, 0);
+MODULE_PARM_DESC(base, "ACCES 104-IDIO-16 base addresses");
+
+static unsigned int irq[MAX_NUM_IDIO_16];
+module_param_array(irq, uint, NULL, 0);
+MODULE_PARM_DESC(irq, "ACCES 104-IDIO-16 interrupt line numbers");

/**
* struct idio_16_gpio - GPIO device private data structure
@@ -185,23 +193,19 @@ static irqreturn_t idio_16_irq_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static int __init idio_16_probe(struct platform_device *pdev)
+static int idio_16_probe(struct device *dev, unsigned int id)
{
- struct device *dev = &pdev->dev;
struct idio_16_gpio *idio16gpio;
- const unsigned base = idio_16_base;
- const unsigned extent = 8;
const char *const name = dev_name(dev);
int err;
- const unsigned irq = idio_16_irq;

idio16gpio = devm_kzalloc(dev, sizeof(*idio16gpio), GFP_KERNEL);
if (!idio16gpio)
return -ENOMEM;

- if (!devm_request_region(dev, base, extent, name)) {
+ if (!devm_request_region(dev, base[id], IDIO_16_EXTENT, name)) {
dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
- base, base + extent);
+ base[id], base[id] + IDIO_16_EXTENT);
return -EBUSY;
}

@@ -215,8 +219,8 @@ static int __init idio_16_probe(struct platform_device *pdev)
idio16gpio->chip.direction_output = idio_16_gpio_direction_output;
idio16gpio->chip.get = idio_16_gpio_get;
idio16gpio->chip.set = idio_16_gpio_set;
- idio16gpio->base = base;
- idio16gpio->irq = irq;
+ idio16gpio->base = base[id];
+ idio16gpio->irq = irq[id];
idio16gpio->out_state = 0xFFFF;

spin_lock_init(&idio16gpio->lock);
@@ -230,8 +234,8 @@ static int __init idio_16_probe(struct platform_device *pdev)
}

/* Disable IRQ by default */
- outb(0, base + 2);
- outb(0, base + 1);
+ outb(0, base[id] + 2);
+ outb(0, base[id] + 1);

err = gpiochip_irqchip_add(&idio16gpio->chip, &idio_16_irqchip, 0,
handle_edge_irq, IRQ_TYPE_NONE);
@@ -240,7 +244,7 @@ static int __init idio_16_probe(struct platform_device *pdev)
goto err_gpiochip_remove;
}

- err = request_irq(irq, idio_16_irq_handler, 0, name, idio16gpio);
+ err = request_irq(irq[id], idio_16_irq_handler, 0, name, idio16gpio);
if (err) {
dev_err(dev, "IRQ handler registering failed (%d)\n", err);
goto err_gpiochip_remove;
@@ -253,9 +257,9 @@ err_gpiochip_remove:
return err;
}

-static int idio_16_remove(struct platform_device *pdev)
+static int idio_16_remove(struct device *dev, unsigned int id)
{
- struct idio_16_gpio *const idio16gpio = platform_get_drvdata(pdev);
+ struct idio_16_gpio *const idio16gpio = dev_get_drvdata(dev);

free_irq(idio16gpio->irq, idio16gpio);
gpiochip_remove(&idio16gpio->chip);
@@ -263,48 +267,15 @@ static int idio_16_remove(struct platform_device *pdev)
return 0;
}

-static struct platform_device *idio_16_device;
-
-static struct platform_driver idio_16_driver = {
+static struct isa_driver idio_16_driver = {
+ .probe = idio_16_probe,
.driver = {
.name = "104-idio-16"
},
.remove = idio_16_remove
};

-static void __exit idio_16_exit(void)
-{
- platform_device_unregister(idio_16_device);
- platform_driver_unregister(&idio_16_driver);
-}
-
-static int __init idio_16_init(void)
-{
- int err;
-
- idio_16_device = platform_device_alloc(idio_16_driver.driver.name, -1);
- if (!idio_16_device)
- return -ENOMEM;
-
- err = platform_device_add(idio_16_device);
- if (err)
- goto err_platform_device;
-
- err = platform_driver_probe(&idio_16_driver, idio_16_probe);
- if (err)
- goto err_platform_driver;
-
- return 0;
-
-err_platform_driver:
- platform_device_del(idio_16_device);
-err_platform_device:
- platform_device_put(idio_16_device);
- return err;
-}
-
-module_init(idio_16_init);
-module_exit(idio_16_exit);
+module_isa_driver(idio_16_driver, num_idio_16);

MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@xxxxxxxxx>");
MODULE_DESCRIPTION("ACCES 104-IDIO-16 GPIO driver");
--
2.7.3