[PATCH v2 0/4] OF GPIO integration for I2C/SPI GPIO chips
Anton Vorontsov
Here comes v2. Changes:
- In 'gpiolib: Introduce chip addition/removal notifier', open-coded
gpio_call_chain().
- In 'of/gpio: Add support for two-stage registration for the
of_gpio_chips', improved commit message.
David, I think it would be best if these patches could go via powerpc
or OF trees, so your Ack would be highly appreciated.
Thanks!
--
Anton Vorontsov
email: cbouat...@gmail.com
irc://irc.freenode.net/bd2
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Anton Vorontsov
GPIO controllers, i.e. now drivers don't have to deal with the
OF-specific bits.
Signed-off-by: Anton Vorontsov <avoro...@ru.mvista.com>
---
arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c | 68 +++++-------------------
1 files changed, 14 insertions(+), 54 deletions(-)
diff --git a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
index 73c7e6b..5525175 100644
--- a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
+++ b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
@@ -18,8 +18,6 @@
#include <linux/mutex.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
-#include <linux/of.h>
-#include <linux/of_gpio.h>
#include <asm/prom.h>
#include <asm/machdep.h>
@@ -36,7 +34,7 @@ struct mcu {
struct mutex lock;
struct device_node *np;
struct i2c_client *client;
- struct of_gpio_chip of_gc;
+ struct gpio_chip gc;
u8 reg_ctrl;
};
@@ -55,8 +53,7 @@ static void mcu_power_off(void)
static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
- struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
- struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
+ struct mcu *mcu = container_of(gc, struct mcu, gc);
u8 bit = 1 << (4 + gpio);
mutex_lock(&mcu->lock);
@@ -75,53 +72,6 @@ static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
return 0;
}
-static int mcu_gpiochip_add(struct mcu *mcu)
-{
- struct device_node *np;
- struct of_gpio_chip *of_gc = &mcu->of_gc;
- struct gpio_chip *gc = &of_gc->gc;
- int ret;
-
- np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
- if (!np)
- return -ENODEV;
-
- gc->owner = THIS_MODULE;
- gc->label = np->full_name;
- gc->can_sleep = 1;
- gc->ngpio = MCU_NUM_GPIO;
- gc->base = -1;
- gc->set = mcu_gpio_set;
- gc->direction_output = mcu_gpio_dir_out;
- of_gc->chip = gc;
- of_gc->gpio_cells = 2;
- of_gc->xlate = of_gpio_simple_xlate;
-
- np->data = of_gc;
- mcu->np = np;
-
- /*
- * We don't want to lose the node, its ->data and ->full_name...
- * So, if succeeded, we don't put the node here.
- */
- ret = gpiochip_add(gc);
- if (ret)
- of_node_put(np);
- return ret;
-}
-
-static int mcu_gpiochip_remove(struct mcu *mcu)
-{
- int ret;
-
- ret = gpiochip_remove(&mcu->of_gc.gc);
- if (ret)
- return ret;
- of_node_put(mcu->np);
-
- return 0;
-}
-
static int __devinit mcu_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -141,7 +91,16 @@ static int __devinit mcu_probe(struct i2c_client *client,
goto err;
mcu->reg_ctrl = ret;
- ret = mcu_gpiochip_add(mcu);
+ mcu->gc.dev = &client->dev;
+ mcu->gc.owner = THIS_MODULE;
+ mcu->gc.label = dev_name(&client->dev);
+ mcu->gc.can_sleep = 1;
+ mcu->gc.ngpio = MCU_NUM_GPIO;
+ mcu->gc.base = -1;
+ mcu->gc.set = mcu_gpio_set;
+ mcu->gc.direction_output = mcu_gpio_dir_out;
+
+ ret = gpiochip_add(&mcu->gc);
if (ret)
goto err;
@@ -168,9 +127,10 @@ static int __devexit mcu_remove(struct i2c_client *client)
glob_mcu = NULL;
}
- ret = mcu_gpiochip_remove(mcu);
+ ret = gpiochip_remove(&mcu->gc);
if (ret)
return ret;
+
i2c_set_clientdata(client, NULL);
kfree(mcu);
return 0;
--
1.6.5.7
Anton Vorontsov
added or removed, so that the platforms could add their specifics for
non-platform devices, like I2C or SPI GPIO chips.
This patch implements the notifier for chip addition and removal events.
Signed-off-by: Anton Vorontsov <avoro...@ru.mvista.com>
---
drivers/gpio/gpiolib.c | 14 ++++++++++++++
include/asm-generic/gpio.h | 8 ++++++++
2 files changed, 22 insertions(+), 0 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 350842a..375c03a 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -9,6 +9,7 @@
#include <linux/seq_file.h>
#include <linux/gpio.h>
#include <linux/idr.h>
+#include <linux/notifier.h>
/* Optional implementation infrastructure for GPIO interfaces.
@@ -1029,6 +1030,9 @@ static inline void gpiochip_unexport(struct gpio_chip *chip)
#endif /* CONFIG_GPIO_SYSFS */
+BLOCKING_NOTIFIER_HEAD(gpio_notifier);
+EXPORT_SYMBOL_GPL(gpio_notifier);
+
/**
* gpiochip_add() - register a gpio_chip
* @chip: the chip to register, with chip->base initialized
@@ -1103,6 +1107,9 @@ fail:
pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
chip->base, chip->base + chip->ngpio - 1,
chip->label ? : "generic");
+ else
+ blocking_notifier_call_chain(&gpio_notifier,
+ GPIO_NOTIFY_CHIP_ADDED, chip);
return status;
}
EXPORT_SYMBOL_GPL(gpiochip_add);
@@ -1119,6 +1126,13 @@ int gpiochip_remove(struct gpio_chip *chip)
int status = 0;
unsigned id;
+ /* Ask external subsystems to release the chip. */
+ status = blocking_notifier_call_chain(&gpio_notifier,
+ GPIO_NOTIFY_CHIP_REMOVE, chip);
+ status = notifier_to_errno(status);
+ if (status)
+ return status;
+
spin_lock_irqsave(&gpio_lock, flags);
for (id = chip->base; id < chip->base + chip->ngpio; id++) {
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 485eeb6..84faae4 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -4,6 +4,7 @@
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
+#include <linux/notifier.h>
#ifdef CONFIG_GPIOLIB
@@ -208,4 +209,11 @@ static inline void gpio_unexport(unsigned gpio)
}
#endif /* CONFIG_GPIO_SYSFS */
+enum gpio_notify_msg {
+ GPIO_NOTIFY_CHIP_ADDED = 0,
+ GPIO_NOTIFY_CHIP_REMOVE = 1,
+};
+
+extern struct blocking_notifier_head gpio_notifier;
+
#endif /* _ASM_GENERIC_GPIO_H */
--
1.6.5.7
Anton Vorontsov
'struct gpio_chip gc' in the OF GPIO subsystem, instead we need to store
just a pointer, and then attach the already allocated gpio_chip to the
of_gpio_chip structure.
With this patch there are two ways to register OF GPIO controllers:
1. Allocating the of_gpio_chip structure and passing the
&of_gc->gc pointer to the gpiochip_add. (Can use container_of
to convert the gpio_chip to the of_gpio_chip.)
2. Allocating and registering the gpio_chip structure separately
from the of_gpio_chip. (Since two allocations are separate,
container_of won't work.)
As time goes by we'll kill the first option.
Signed-off-by: Anton Vorontsov <avoro...@ru.mvista.com>
---
arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c | 1 +
drivers/of/gpio.c | 23 +++++++++++++++++++++--
include/linux/of_gpio.h | 3 ++-
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
index 82a9bcb..73c7e6b 100644
--- a/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
+++ b/arch/powerpc/platforms/83xx/mcu_mpc8349emitx.c
@@ -93,6 +93,7 @@ static int mcu_gpiochip_add(struct mcu *mcu)
gc->base = -1;
gc->set = mcu_gpio_set;
gc->direction_output = mcu_gpio_dir_out;
+ of_gc->chip = gc;
of_gc->gpio_cells = 2;
of_gc->xlate = of_gpio_simple_xlate;
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index 6eea601..12c4af0 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -70,7 +70,7 @@ int of_get_gpio_flags(struct device_node *np, int index,
if (ret < 0)
goto err1;
- ret += of_gc->gc.base;
+ ret += of_gc->chip->base;
err1:
of_node_put(gc);
err0:
@@ -140,7 +140,7 @@ int of_gpio_simple_xlate(struct of_gpio_chip *of_gc, struct device_node *np,
return -EINVAL;
}
- if (*gpio > of_gc->gc.ngpio)
+ if (*gpio > of_gc->chip->ngpio)
return -EINVAL;
if (flags)
@@ -178,6 +178,25 @@ int of_mm_gpiochip_add(struct device_node *np,
struct of_gpio_chip *of_gc = &mm_gc->of_gc;
struct gpio_chip *gc = &of_gc->gc;
+ /*
+ * Currently there are two ways to register OF GPIO controllers:
+ *
+ * 1. Allocating the of_gpio_chip structure and passing the
+ * &of_gc->gc pointer to the gpiochip_add. (Can use container_of
+ * to convert the gpio_chip to the of_gpio_chip.)
+ *
+ * 2. Allocating and registering the gpio_chip structure separately
+ * from the of_gpio_chip. (Since two allocations are separate,
+ * container_of won't work.)
+ *
+ * As time goes by we'll kill the first option. For now just check
+ * if it's the new-style registration or the old-style.
+ */
+ if (!of_gc->chip)
+ of_gc->chip = gc;
+ else
+ gc = of_gc->chip;
+
gc->label = kstrdup(np->full_name, GFP_KERNEL);
if (!gc->label)
goto err0;
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index fc2472c..c74cb37 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -36,7 +36,8 @@ enum of_gpio_flags {
* Generic OF GPIO chip
*/
struct of_gpio_chip {
- struct gpio_chip gc;
+ struct gpio_chip gc; /* legacy, don't use for a new code */
+ struct gpio_chip *chip;
int gpio_cells;
int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
const void *gpio_spec, enum of_gpio_flags *flags);
--
1.6.5.7
Grant Likely
Rather than doing an else block which will need to be reworked if/when
any additional code is added to the bottom of this routine, please
rework the if() block to bail on failure instead of implicitly falling
through to the return statement.
Otherwise, this patch looks okay to me, so you can go ahead and add my:
Acked-by: Grant Likely <grant....@secretlab.ca>
*however* (and don't kill me for saying this because I know I
suggested the notifier approach in the first place). Looking at the
whole patch series, the notifier call adds a lot of code for very
little gain. If you dropped just the notifier bits (but left the rest
of the series the same), then the the of gpio bits would be
considerably simpler, and the only impact on the core gpiolib would be
the addition of an of_gpiochip_register_simple() and
of_gpiochip_unregister() hooks that will be conditionally compiled.
And to address one of my previous concerns, I've got no problem with
the automatic registration of GPIO devices for OF usage, as long as
of-aware drivers have the option of overriding the simple defaults
when needed.
g.
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
Andrew Morton
This still hasn't happened.
> Otherwise, this patch looks okay to me, so you can go ahead and add my:
>
> Acked-by: Grant Likely <grant....@secretlab.ca>
>
I'll merge it anyway and will ask you guys to keep track of this issue,
thanks.
Anton Vorontsov
[...]
> > > /**
> > > * gpiochip_add() - register a gpio_chip
> > > * @chip: the chip to register, with chip->base initialized
> > > @@ -1103,6 +1107,9 @@ fail:
> > > pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
> > > chip->base, chip->base + chip->ngpio - 1,
> > > chip->label ? : "generic");
> > > + else
> > > + blocking_notifier_call_chain(&gpio_notifier,
> > > + GPIO_NOTIFY_CHIP_ADDED, chip);
> >
> > Rather than doing an else block which will need to be reworked if/when
> > any additional code is added to the bottom of this routine, please
> > rework the if() block to bail on failure instead of implicitly falling
> > through to the return statement.
>
> This still hasn't happened.
It's in your tree already :-)
gpiolib-cosmetic-improvements-for-error-handling-in-gpiochip_add.patch
--
Anton Vorontsov
email: cbouat...@gmail.com
irc://irc.freenode.net/bd2