* [PATCH v2] spi: enable spi_board_info to be registered after spi_master
@ 2010-07-28 2:39 Feng Tang
[not found] ` <1280284796-26136-1-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
0 siblings, 1 reply; 2+ messages in thread
From: Feng Tang @ 2010-07-28 2:39 UTC (permalink / raw)
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Cc: david-b-yBeKhBN/0LDR7s880joybQ, David Brownell,
alan-VuQAYsv1563Yd54FQh9/CA
Currently spi_register_board_info() has to be called before its related
spi_master be registered, otherwise these board info will be just ignored.
This patch will remove this order limit, it adds a global spi master list
like the existing global board info listr. Whenever a board info is
registered, the spi master list will be scanned, and a new spi device will
be created if master and boardinfo match.
Cc: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
Signed-off-by: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/spi/spi.c | 73 ++++++++++++++++++++++++++++++++++-------------
include/linux/spi/spi.h | 3 ++
2 files changed, 56 insertions(+), 20 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index b3a1f92..1266fb2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -196,13 +196,16 @@ EXPORT_SYMBOL_GPL(spi_register_driver);
struct boardinfo {
struct list_head list;
- unsigned n_board_info;
- struct spi_board_info board_info[0];
+ struct spi_board_info board_info;
};
static LIST_HEAD(board_list);
static DEFINE_MUTEX(board_lock);
+
+static LIST_HEAD(spi_master_list);
+static DEFINE_MUTEX(spi_master_lock);
+
/**
* spi_alloc_device - Allocate a new SPI device
* @master: Controller to which device is connected
@@ -365,6 +368,25 @@ struct spi_device *spi_new_device(struct spi_master *master,
}
EXPORT_SYMBOL_GPL(spi_new_device);
+static void spi_scan_masterlist(struct spi_board_info *bi)
+{
+ struct spi_master *master;
+ struct spi_device *dev;
+
+ mutex_lock(&spi_master_lock);
+ list_for_each_entry(master, &spi_master_list, list) {
+ if (master->bus_num != bi->bus_num)
+ continue;
+
+ dev = spi_new_device(master, bi);
+ if (!dev)
+ dev_err(master->dev.parent,
+ "can't create new device for %s\n",
+ bi->modalias);
+ }
+ mutex_unlock(&spi_master_lock);
+}
+
/**
* spi_register_board_info - register SPI devices for a given board
* @info: array of chip descriptors
@@ -387,41 +409,45 @@ EXPORT_SYMBOL_GPL(spi_new_device);
int __init
spi_register_board_info(struct spi_board_info const *info, unsigned n)
{
- struct boardinfo *bi;
+ struct boardinfo *bi, *tmp_bi;
+ int i;
- bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
+ bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
if (!bi)
return -ENOMEM;
- bi->n_board_info = n;
- memcpy(bi->board_info, info, n * sizeof *info);
mutex_lock(&board_lock);
- list_add_tail(&bi->list, &board_list);
+ for (i = 0, tmp_bi = bi; i < n; i++, tmp_bi++, info++) {
+ memcpy(&tmp_bi->board_info, info, sizeof(*info));
+ list_add_tail(&tmp_bi->list, &board_list);
+ }
mutex_unlock(&board_lock);
+
+ for (i = 0, tmp_bi = bi; i < n; i++, tmp_bi++)
+ spi_scan_masterlist(&tmp_bi->board_info);
+
return 0;
}
/* FIXME someone should add support for a __setup("spi", ...) that
* creates board info from kernel command lines
*/
-
static void scan_boardinfo(struct spi_master *master)
{
struct boardinfo *bi;
+ struct spi_device *dev;
mutex_lock(&board_lock);
list_for_each_entry(bi, &board_list, list) {
- struct spi_board_info *chip = bi->board_info;
- unsigned n;
-
- for (n = bi->n_board_info; n > 0; n--, chip++) {
- if (chip->bus_num != master->bus_num)
- continue;
- /* NOTE: this relies on spi_new_device to
- * issue diagnostics when given bogus inputs
- */
- (void) spi_new_device(master, chip);
- }
+ struct spi_board_info *chip = &bi->board_info;
+
+ if (chip->bus_num != master->bus_num)
+ continue;
+ dev = spi_new_device(master, chip);
+ if (!dev)
+ dev_err(master->dev.parent,
+ "can't create new device for %s\n",
+ chip->modalias);
}
mutex_unlock(&board_lock);
}
@@ -537,15 +563,18 @@ int spi_register_master(struct spi_master *master)
dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
dynamic ? " (dynamic)" : "");
+ mutex_lock(&spi_master_lock);
+ list_add_tail(&master->list, &spi_master_list);
/* populate children from any spi device tables */
scan_boardinfo(master);
+ mutex_unlock(&spi_master_lock);
+
status = 0;
done:
return status;
}
EXPORT_SYMBOL_GPL(spi_register_master);
-
static int __unregister(struct device *dev, void *master_dev)
{
/* note: before about 2.6.14-rc1 this would corrupt memory: */
@@ -568,6 +597,10 @@ void spi_unregister_master(struct spi_master *master)
{
int dummy;
+ mutex_lock(&spi_master_lock);
+ list_del(&master->list);
+ mutex_unlock(&spi_master_lock);
+
dummy = device_for_each_child(master->dev.parent, &master->dev,
__unregister);
device_unregister(&master->dev);
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index af56071..f4a29b6 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -204,6 +204,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
/**
* struct spi_master - interface to SPI master controller
* @dev: device interface to this driver
+ * @list: link with the global spi_master list
* @bus_num: board-specific (and often SOC-specific) identifier for a
* given SPI controller.
* @num_chipselect: chipselects are used to distinguish individual
@@ -235,6 +236,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
struct spi_master {
struct device dev;
+ struct list_head list;
+
/* other than negative (== assign one dynamically), bus_num is fully
* board-specific. usually that simplifies to being SOC-specific.
* example: one SOC has three SPI controllers, numbered 0..2,
--
1.7.0.4
------------------------------------------------------------------------------
The Palm PDK Hot Apps Program offers developers who use the
Plug-In Development Kit to bring their C/C++ apps to Palm for a share
of $1 Million in cash or HP Products. Visit us here for more details:
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] spi: enable spi_board_info to be registered after spi_master
[not found] ` <1280284796-26136-1-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
@ 2010-08-01 7:19 ` Grant Likely
0 siblings, 0 replies; 2+ messages in thread
From: Grant Likely @ 2010-08-01 7:19 UTC (permalink / raw)
To: Feng Tang
Cc: david-b-yBeKhBN/0LDR7s880joybQ,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f,
David Brownell, alan-VuQAYsv1563Yd54FQh9/CA
On Tue, Jul 27, 2010 at 8:39 PM, Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> Currently spi_register_board_info() has to be called before its related
> spi_master be registered, otherwise these board info will be just ignored.
>
> This patch will remove this order limit, it adds a global spi master list
> like the existing global board info listr. Whenever a board info is
> registered, the spi master list will be scanned, and a new spi device will
> be created if master and boardinfo match.
>
> Cc: David Brownell <dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org>
> Cc: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
> Signed-off-by: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
> drivers/spi/spi.c | 73 ++++++++++++++++++++++++++++++++++-------------
> include/linux/spi/spi.h | 3 ++
> 2 files changed, 56 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index b3a1f92..1266fb2 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -196,13 +196,16 @@ EXPORT_SYMBOL_GPL(spi_register_driver);
>
> struct boardinfo {
> struct list_head list;
> - unsigned n_board_info;
> - struct spi_board_info board_info[0];
> + struct spi_board_info board_info;
> };
>
> static LIST_HEAD(board_list);
> static DEFINE_MUTEX(board_lock);
>
> +
> +static LIST_HEAD(spi_master_list);
> +static DEFINE_MUTEX(spi_master_lock);
> +
> /**
> * spi_alloc_device - Allocate a new SPI device
> * @master: Controller to which device is connected
> @@ -365,6 +368,25 @@ struct spi_device *spi_new_device(struct spi_master *master,
> }
> EXPORT_SYMBOL_GPL(spi_new_device);
>
> +static void spi_scan_masterlist(struct spi_board_info *bi)
> +{
> + struct spi_master *master;
> + struct spi_device *dev;
> +
> + mutex_lock(&spi_master_lock);
> + list_for_each_entry(master, &spi_master_list, list) {
> + if (master->bus_num != bi->bus_num)
> + continue;
> +
> + dev = spi_new_device(master, bi);
> + if (!dev)
> + dev_err(master->dev.parent,
> + "can't create new device for %s\n",
> + bi->modalias);
> + }
> + mutex_unlock(&spi_master_lock);
> +}
> +
> /**
> * spi_register_board_info - register SPI devices for a given board
> * @info: array of chip descriptors
> @@ -387,41 +409,45 @@ EXPORT_SYMBOL_GPL(spi_new_device);
> int __init
> spi_register_board_info(struct spi_board_info const *info, unsigned n)
> {
> - struct boardinfo *bi;
> + struct boardinfo *bi, *tmp_bi;
> + int i;
>
> - bi = kmalloc(sizeof(*bi) + n * sizeof *info, GFP_KERNEL);
> + bi = kzalloc(n * sizeof(*bi), GFP_KERNEL);
> if (!bi)
> return -ENOMEM;
> - bi->n_board_info = n;
> - memcpy(bi->board_info, info, n * sizeof *info);
>
> mutex_lock(&board_lock);
> - list_add_tail(&bi->list, &board_list);
> + for (i = 0, tmp_bi = bi; i < n; i++, tmp_bi++, info++) {
> + memcpy(&tmp_bi->board_info, info, sizeof(*info));
> + list_add_tail(&tmp_bi->list, &board_list);
> + }
> mutex_unlock(&board_lock);
> +
> + for (i = 0, tmp_bi = bi; i < n; i++, tmp_bi++)
> + spi_scan_masterlist(&tmp_bi->board_info);
> +
Race condition here also. If a master gets registered between
releasing the lock and calling spi_scan_masterlist(), then the devices
could again get registered twice. I still think a single mutex should
be sufficient to protect both lists.
> return 0;
> }
>
> /* FIXME someone should add support for a __setup("spi", ...) that
> * creates board info from kernel command lines
> */
> -
> static void scan_boardinfo(struct spi_master *master)
> {
> struct boardinfo *bi;
> + struct spi_device *dev;
>
> mutex_lock(&board_lock);
> list_for_each_entry(bi, &board_list, list) {
> - struct spi_board_info *chip = bi->board_info;
> - unsigned n;
> -
> - for (n = bi->n_board_info; n > 0; n--, chip++) {
> - if (chip->bus_num != master->bus_num)
> - continue;
> - /* NOTE: this relies on spi_new_device to
> - * issue diagnostics when given bogus inputs
> - */
> - (void) spi_new_device(master, chip);
> - }
> + struct spi_board_info *chip = &bi->board_info;
> +
> + if (chip->bus_num != master->bus_num)
> + continue;
> + dev = spi_new_device(master, chip);
> + if (!dev)
> + dev_err(master->dev.parent,
> + "can't create new device for %s\n",
> + chip->modalias);
> }
> mutex_unlock(&board_lock);
> }
> @@ -537,15 +563,18 @@ int spi_register_master(struct spi_master *master)
> dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev),
> dynamic ? " (dynamic)" : "");
>
> + mutex_lock(&spi_master_lock);
> + list_add_tail(&master->list, &spi_master_list);
> /* populate children from any spi device tables */
> scan_boardinfo(master);
> + mutex_unlock(&spi_master_lock);
> +
> status = 0;
> done:
> return status;
> }
> EXPORT_SYMBOL_GPL(spi_register_master);
>
> -
> static int __unregister(struct device *dev, void *master_dev)
> {
> /* note: before about 2.6.14-rc1 this would corrupt memory: */
> @@ -568,6 +597,10 @@ void spi_unregister_master(struct spi_master *master)
> {
> int dummy;
>
> + mutex_lock(&spi_master_lock);
> + list_del(&master->list);
> + mutex_unlock(&spi_master_lock);
> +
> dummy = device_for_each_child(master->dev.parent, &master->dev,
> __unregister);
> device_unregister(&master->dev);
> diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
> index af56071..f4a29b6 100644
> --- a/include/linux/spi/spi.h
> +++ b/include/linux/spi/spi.h
> @@ -204,6 +204,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
> /**
> * struct spi_master - interface to SPI master controller
> * @dev: device interface to this driver
> + * @list: link with the global spi_master list
> * @bus_num: board-specific (and often SOC-specific) identifier for a
> * given SPI controller.
> * @num_chipselect: chipselects are used to distinguish individual
> @@ -235,6 +236,8 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
> struct spi_master {
> struct device dev;
>
> + struct list_head list;
> +
> /* other than negative (== assign one dynamically), bus_num is fully
> * board-specific. usually that simplifies to being SOC-specific.
> * example: one SOC has three SPI controllers, numbered 0..2,
> --
> 1.7.0.4
>
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
------------------------------------------------------------------------------
The Palm PDK Hot Apps Program offers developers who use the
Plug-In Development Kit to bring their C/C++ apps to Palm for a share
of $1 Million in cash or HP Products. Visit us here for more details:
http://p.sf.net/sfu/dev2dev-palm
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2010-07-28 2:39 [PATCH v2] spi: enable spi_board_info to be registered after spi_master Feng Tang
[not found] ` <1280284796-26136-1-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2010-08-01 7:19 ` Grant Likely
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