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Date: Tue, 19 Apr 2011 20:40:48 +0400
From: Anton Vorontsov <cbouatmailru@...il.com>
To: Alan Cox <alan@...rguk.ukuu.org.uk>
Cc: Grant Likely <grant.likely@...retlab.ca>,
Jean Delvare <khali@...ux-fr.org>,
LKML <linux-kernel@...r.kernel.org>,
Jamie Iles <jamie@...ieiles.com>,
Mark Brown <broonie@...nsource.wolfsonmicro.com>, arnd@...db.de
Subject: Re: [PATCH] gpio: New driver for the Intel 82801 (ICH) GPIO pins
On Tue, Apr 19, 2011 at 04:57:46PM +0100, Alan Cox wrote:
> > Doing a platform device is one solution that is pretty simple to
> > implement and I don't think adding child devices is at all a problem.
> > However, I'm not mandating that approach, and if you or Jean prefer to
> > abstract out the gpio accessors from basic_mmio_gpio(), then that is
> > fine by me. The key issue it to avoid merging yet another, probably
> > subtly broken, set of GPIO accessor functions if it can at all be
> > avoided.
>
> As is adding a set of subtly broken attempts to create device stacks that
> then get into funny sysfs and power management tangles. As well as being
> about 12K larger due to the need to suck in an extra module.
>
> I can see the point of splitting out the accessors but if thats a module
> of its own then thats another 8K we don't need to waste on a few hundred
> bytes of utterly trivial code.
How about exporting some bus/device-type neutral probe function, like
we do in drivers/ata/pata_platform.c ?
That way bus-specific probe functions may call the generic routines.
And if you still want to save 8K, you could place the PCI bindings
inside the basic_mmio_gpio.
The patch below is against Linus tree + the following patches from
Jamie Iles:
basic_mmio_gpio: remove runtime width/endianness evaluation
basic_mmio_gpio: convert to platform_{get,set}_drvdata()
basic_mmio_gpio: allow overriding number of gpio
basic_mmio_gpio: request register regions
basic_mmio_gpio: detect output method at probe time
basic_mmio_gpio: support different input/output registers
basic_mmio_gpio: support direction registers
basic_mmio_gpio: convert to non-__raw* accessors
Not-yet-signed-off-by: Anton Vorontsov <cbouatmailru@...il.com>
and only compile tested so far, just an idea:
---
drivers/gpio/Kconfig | 6 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/basic_mmio_gpio.c | 98 ++++++++++++++++++++++----------------
include/linux/basic_mmio_gpio.h | 14 ++++++
4 files changed, 78 insertions(+), 41 deletions(-)
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 664660e..88dd650 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -70,8 +70,14 @@ config GPIO_MAX730X
comment "Memory mapped GPIO expanders:"
+config GPIO_BASIC_MMIO_CORE
+ tristate
+ help
+ Provides core functionality for basic memory-mapped GPIO controllers.
+
config GPIO_BASIC_MMIO
tristate "Basic memory-mapped GPIO controllers support"
+ select GPIO_BASIC_MMIO_CORE
help
Say yes here to support basic memory-mapped GPIO controllers.
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 3351cf8..1abf916 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o
obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o
+obj-$(CONFIG_GPIO_BASIC_MMIO_CORE) += basic_mmio_gpio.o
obj-$(CONFIG_GPIO_BASIC_MMIO) += basic_mmio_gpio.o
obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
obj-$(CONFIG_GPIO_MAX730X) += max730x.o
diff --git a/drivers/gpio/basic_mmio_gpio.c b/drivers/gpio/basic_mmio_gpio.c
index b2ec45f..3deb1d7 100644
--- a/drivers/gpio/basic_mmio_gpio.c
+++ b/drivers/gpio/basic_mmio_gpio.c
@@ -294,10 +294,10 @@ static void __iomem *bgpio_request_and_map(struct device *dev,
return devm_ioremap(dev, res->start, resource_size(res));
}
-static int bgpio_setup_accessors(struct platform_device *pdev,
- struct bgpio_chip *bgc)
+static int bgpio_setup_accessors(struct device *dev,
+ struct bgpio_chip *bgc,
+ bool be)
{
- const struct platform_device_id *platid = platform_get_device_id(pdev);
switch (bgc->bits) {
case 8:
@@ -319,13 +319,11 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
break;
#endif /* BITS_PER_LONG >= 64 */
default:
- dev_err(&pdev->dev, "unsupported data width %u bits\n",
- bgc->bits);
+ dev_err(dev, "unsupported data width %u bits\n", bgc->bits);
return -EINVAL;
}
- bgc->pin2mask = strcmp(platid->name, "basic-mmio-gpio-be") ?
- bgpio_pin2mask : bgpio_pin2mask_be;
+ bgc->pin2mask = be ? bgpio_pin2mask_be : bgpio_pin2mask;
return 0;
}
@@ -352,18 +350,14 @@ static int bgpio_setup_accessors(struct platform_device *pdev,
* - an input direction register (named "dirin") where a 1 bit indicates
* the GPIO is an input.
*/
-static int bgpio_setup_io(struct platform_device *pdev,
- struct bgpio_chip *bgc)
+static int bgpio_setup_io(struct device *dev,
+ struct bgpio_chip *bgc,
+ struct resource *res_dat,
+ struct resource *res_set,
+ struct resource *res_clr)
{
- struct resource *res_set;
- struct resource *res_clr;
- struct resource *res_dat;
resource_size_t dat_sz;
- res_dat = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat");
- if (!res_dat)
- return -EINVAL;
-
dat_sz = resource_size(res_dat);
if (!is_power_of_2(dat_sz))
return -EINVAL;
@@ -372,19 +366,17 @@ static int bgpio_setup_io(struct platform_device *pdev,
if (bgc->bits > BITS_PER_LONG)
return -EINVAL;
- bgc->reg_dat = bgpio_request_and_map(&pdev->dev, res_dat);
+ bgc->reg_dat = bgpio_request_and_map(dev, res_dat);
if (!bgc->reg_dat)
return -ENOMEM;
- res_set = platform_get_resource_byname(pdev, IORESOURCE_MEM, "set");
- res_clr = platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr");
if (res_set && res_clr) {
if (resource_size(res_set) != resource_size(res_clr) ||
resource_size(res_set) != resource_size(res_dat))
return -EINVAL;
- bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
- bgc->reg_clr = bgpio_request_and_map(&pdev->dev, res_clr);
+ bgc->reg_set = bgpio_request_and_map(dev, res_set);
+ bgc->reg_clr = bgpio_request_and_map(dev, res_clr);
if (!bgc->reg_set || !bgc->reg_clr)
return -ENOMEM;
@@ -393,7 +385,7 @@ static int bgpio_setup_io(struct platform_device *pdev,
if (resource_size(res_set) != resource_size(res_dat))
return -EINVAL;
- bgc->reg_set = bgpio_request_and_map(&pdev->dev, res_set);
+ bgc->reg_set = bgpio_request_and_map(dev, res_set);
if (!bgc->reg_set)
return -ENOMEM;
@@ -407,25 +399,21 @@ static int bgpio_setup_io(struct platform_device *pdev,
return 0;
}
-static int bgpio_setup_direction(struct platform_device *pdev,
- struct bgpio_chip *bgc)
+static int bgpio_setup_direction(struct device *dev,
+ struct bgpio_chip *bgc,
+ struct resource *res_dirout,
+ struct resource *res_dirin)
{
- struct resource *res_dirout;
- struct resource *res_dirin;
-
- res_dirout = platform_get_resource_byname(pdev, IORESOURCE_MEM,
- "dirout");
- res_dirin = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin");
if (res_dirout && res_dirin) {
return -EINVAL;
} else if (res_dirout) {
- bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirout);
+ bgc->reg_dir = bgpio_request_and_map(dev, res_dirout);
if (!bgc->reg_dir)
return -ENOMEM;
bgc->gc.direction_output = bgpio_dir_out;
bgc->gc.direction_input = bgpio_dir_in;
} else if (res_dirin) {
- bgc->reg_dir = bgpio_request_and_map(&pdev->dev, res_dirin);
+ bgc->reg_dir = bgpio_request_and_map(dev, res_dirin);
if (!bgc->reg_dir)
return -ENOMEM;
bgc->gc.direction_output = bgpio_dir_out_inv;
@@ -438,9 +426,22 @@ static int bgpio_setup_direction(struct platform_device *pdev,
return 0;
}
-static int __devinit bgpio_probe(struct platform_device *pdev)
+int __devexit __bgpio_remove(struct device *dev)
+{
+ struct bgpio_chip *bgc = dev_get_drvdata(dev);
+
+ return gpiochip_remove(&bgc->gc);
+}
+EXPORT_SYMBOL_GPL(__bgpio_remove);
+
+int __devinit __bgpio_probe(struct device *dev,
+ struct resource *res_dat,
+ struct resource *res_set,
+ struct resource *res_clr,
+ struct resource *res_dirout,
+ struct resource *res_dirin,
+ bool be)
{
- struct device *dev = &pdev->dev;
struct bgpio_pdata *pdata = dev_get_platdata(dev);
struct bgpio_chip *bgc;
int ret;
@@ -450,7 +451,7 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
if (!bgc)
return -ENOMEM;
- ret = bgpio_setup_io(pdev, bgc);
+ ret = bgpio_setup_io(dev, bgc, res_dat, res_set, res_clr);
if (ret)
return ret;
@@ -463,12 +464,12 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
bgc->gc.base = -1;
}
- ret = bgpio_setup_accessors(pdev, bgc);
+ ret = bgpio_setup_accessors(dev, bgc, be);
if (ret)
return ret;
spin_lock_init(&bgc->lock);
- ret = bgpio_setup_direction(pdev, bgc);
+ ret = bgpio_setup_direction(dev, bgc, res_dirout, res_dirin);
if (ret)
return ret;
@@ -478,7 +479,7 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
bgc->gc.dev = dev;
bgc->gc.label = dev_name(dev);
- platform_set_drvdata(pdev, bgc);
+ dev_set_drvdata(dev, bgc);
ret = gpiochip_add(&bgc->gc);
if (ret)
@@ -486,12 +487,25 @@ static int __devinit bgpio_probe(struct platform_device *pdev)
return ret;
}
+EXPORT_SYMBOL_GPL(__bgpio_probe);
-static int __devexit bgpio_remove(struct platform_device *pdev)
+#ifdef CONFIG_GPIO_BASIC_MMIO
+
+static int __devinit bgpio_probe(struct platform_device *pdev)
{
- struct bgpio_chip *bgc = platform_get_drvdata(pdev);
+ return __bgpio_probe(&pdev->dev,
+ platform_get_resource_byname(pdev, IORESOURCE_MEM, "dat"),
+ platform_get_resource_byname(pdev, IORESOURCE_MEM, "set"),
+ platform_get_resource_byname(pdev, IORESOURCE_MEM, "clr"),
+ platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirout"),
+ platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirin"),
+ !strcmp(platform_get_device_id(pdev)->name,
+ "basic-mmio-gpio-be"));
+}
- return gpiochip_remove(&bgc->gc);
+static int __devexit bgpio_remove(struct platform_device *pdev)
+{
+ return __bgpio_remove(&pdev->dev);
}
static const struct platform_device_id bgpio_id_table[] = {
@@ -522,6 +536,8 @@ static void __exit bgpio_exit(void)
}
module_exit(bgpio_exit);
+#endif /* CONFIG_GPIO_BASIC_MMIO */
+
MODULE_DESCRIPTION("Driver for basic memory-mapped GPIO controllers");
MODULE_AUTHOR("Anton Vorontsov <cbouatmailru@...il.com>");
MODULE_LICENSE("GPL");
diff --git a/include/linux/basic_mmio_gpio.h b/include/linux/basic_mmio_gpio.h
index f23ec73..9277e59 100644
--- a/include/linux/basic_mmio_gpio.h
+++ b/include/linux/basic_mmio_gpio.h
@@ -13,9 +13,23 @@
#ifndef __BASIC_MMIO_GPIO_H
#define __BASIC_MMIO_GPIO_H
+#include <linux/types.h>
+
struct bgpio_pdata {
int base;
int ngpio;
};
+struct device;
+struct resource;
+
+int __devexit __bgpio_remove(struct device *dev);
+int __devinit __bgpio_probe(struct device *dev,
+ struct resource *res_dat,
+ struct resource *res_set,
+ struct resource *res_clr,
+ struct resource *res_dirout,
+ struct resource *res_dirin,
+ bool be);
+
#endif /* __BASIC_MMIO_GPIO_H */
--
1.7.4.1
--
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