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gpio: Add GPIO support for the ACCES 104-IDIO-16

PATCH Superseded William Breathitt Gray 2 participants 2 messages Oct 9, 2015 – Oct 16, 2015

Subsystems (2)
GPIO Acces 104-idio-16 GPIO driver

v9 of 10 Superseded Latest is v10 →

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William Breathitt Gray

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#0 lore raw

PATCH v9 1/1 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. The base port address for the device may be set via the a_104_idio_16_base module parameter.

Signed-off-by William Breathitt Gray <[email protected]>

---
Changes in v9:
- Initialize GPIO device private data structure to 0 to prevent garbage data pollution

 drivers/gpio/Kconfig            |  10 ++
 drivers/gpio/Makefile           |   1 +
 drivers/gpio/gpio-104-idio-16.c | 219 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 230 insertions(+)
 create mode 100644 drivers/gpio/gpio-104-idio-16.c
drivers/gpio/Kconfig +10 -0
index 8949b3f..dc843e0 100644
@@ -684,6 +684,16 @@ config GPIO_SX150X
 
 endmenu
 
+menu "ISA GPIO drivers"
+
+config 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.
+
+endmenu
+
 menu "MFD GPIO expanders"
 
 config GPIO_ADP5520
drivers/gpio/Makefile +1 -0
index f79a7c4..6f2fea5 100644
@@ -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
drivers/gpio/gpio-104-idio-16.c new file +219 -0

219 lines not on this page · raw message

Signature · 1 line
2.4.9
#1 lore raw
Quoted 9 lines · William Breathitt Gray

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. The base port address for the device may be set via the a_104_idio_16_base module parameter.

Quoted 5 lines
Signed-off-by William Breathitt Gray <[email protected]>

---
Changes in v9:
- Initialize GPIO device private data structure to 0 to prevent garbage data pollution

Getting there...

drivers/gpio/gpio-104-idio-16.c line 28

Quoted 3 lines
drivers/gpio/gpio-104-idio-16.c new file +3 -0
+static unsigned a_104_idio_16_base;
+module_param(a_104_idio_16_base, uint, 0);
+MODULE_PARM_DESC(a_104_idio_16_base, "ACCES 104-IDIO-16 base address");

This is nice!

drivers/gpio/gpio-104-idio-16.c line 114

Quoted 3 lines
drivers/gpio/gpio-104-idio-16.c new file +3 -0
+static int __init a_104_idio_16_probe(struct platform_device *pdev)
+{
+       struct a_104_idio_16_gpio *const a104idio16gp = pdev->dev.platform_data;

No.

Why not just allocate zeroed it here in probe() like this:

struct a_104_idio_16_gpio *gp;

gp = devm_kzalloc(&pdev->dev, sizeof(*gp), GFP_KERNEL); if (!gp)
return -ENOMEM;

You may want to rename "a_104_idio_16_gpio" to something more everyday. This is hard to type.

drivers/gpio/gpio-104-idio-16.c line 191

Quoted 4 lines
drivers/gpio/gpio-104-idio-16.c new file +4 -0
+static int __init a_104_idio_16_init(void)
+{
+       int err;
+       const struct a_104_idio_16_gpio GP = { 0 };

This just works by chance. The keyword you're looking for is not "const" but "static" if you want this to stay around. But do it as described above instead.

drivers/gpio/gpio-104-idio-16.c line 198

Quoted 6 lines
drivers/gpio/gpio-104-idio-16.c new file +6 -0
+       a_104_idio_16_device = platform_device_register_data(NULL,
+               a_104_idio_16_driver.driver.name, -1, &GP, sizeof(GP));
+       if (IS_ERR(a_104_idio_16_device)) {
+               err = PTR_ERR(a_104_idio_16_device);
+               goto out_platform_device;
+       }

Skip all this. Use devm_kzalloc() in probe as described.

Quoted 4 lines
drivers/gpio/gpio-104-idio-16.c new file +4 -0
+
+       dev_info(&a_104_idio_16_device->dev, "Initializing module\n");
+
+       err = platform_driver_probe(&a_104_idio_16_driver, a_104_idio_16_probe);

drivers/gpio/gpio-104-idio-16.c line 212

Quoted 10 lines
drivers/gpio/gpio-104-idio-16.c new file +10 -0
+       if (err)
+               goto out_platform_driver;
+
+       return 0;
+
+out_platform_driver:
+       platform_device_unregister(a_104_idio_16_device);
+out_platform_device:
+       return err;
+}

Then this can be just return platform_driver_probe(...);

Yours,
Linus Walleij