From 2b9603a0d7e395fb844af90fba71448bc8019077 Mon Sep 17 00:00:00 2001 From: Feng Tang Date: Mon, 2 Aug 2010 15:52:15 +0800 Subject: [PATCH] spi: enable spi_board_info to be registered after spi_master 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 or a spi_master is registered, the spi master list or board info list will be scanned, and a new spi device will be created if there is a master-board info match. Signed-off-by: Feng Tang Signed-off-by: Grant Likely --- drivers/spi/spi.c | 88 ++++++++++++++++++++++------------------- include/linux/spi/spi.h | 3 ++ 2 files changed, 50 insertions(+), 41 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index b5a78a1f4421..0845cd4c5155 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -29,11 +29,6 @@ #include #include - -/* SPI bustype and spi_master class are registered after board init code - * provides the SPI device tables, ensuring that both are present by the - * time controller driver registration causes spi_devices to "enumerate". - */ static void spidev_release(struct device *dev) { struct spi_device *spi = to_spi_device(dev); @@ -202,11 +197,16 @@ 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 LIST_HEAD(spi_master_list); + +/* + * Used to protect add/del opertion for board_info list and + * spi_master list, and their matching process + */ static DEFINE_MUTEX(board_lock); /** @@ -371,6 +371,20 @@ struct spi_device *spi_new_device(struct spi_master *master, } EXPORT_SYMBOL_GPL(spi_new_device); +static void spi_match_master_to_boardinfo(struct spi_master *master, + struct spi_board_info *bi) +{ + struct spi_device *dev; + + if (master->bus_num != bi->bus_num) + return; + + dev = spi_new_device(master, bi); + if (!dev) + dev_err(master->dev.parent, "can't create new device for %s\n", + bi->modalias); +} + /** * spi_register_board_info - register SPI devices for a given board * @info: array of chip descriptors @@ -393,43 +407,25 @@ 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; + 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); - mutex_unlock(&board_lock); - return 0; -} + for (i = 0; i < n; i++, bi++, info++) { + struct spi_master *master; -/* 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; - - 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); - } + memcpy(&bi->board_info, info, sizeof(*info)); + mutex_lock(&board_lock); + list_add_tail(&bi->list, &board_list); + list_for_each_entry(master, &spi_master_list, list) + spi_match_master_to_boardinfo(master, &bi->board_info); + mutex_unlock(&board_lock); } - mutex_unlock(&board_lock); + + return 0; } /*-------------------------------------------------------------------------*/ @@ -512,6 +508,7 @@ int spi_register_master(struct spi_master *master) { static atomic_t dyn_bus_id = ATOMIC_INIT((1<<15) - 1); struct device *dev = master->dev.parent; + struct boardinfo *bi; int status = -ENODEV; int dynamic = 0; @@ -547,8 +544,12 @@ int spi_register_master(struct spi_master *master) dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), dynamic ? " (dynamic)" : ""); - /* populate children from any spi device tables */ - scan_boardinfo(master); + mutex_lock(&board_lock); + list_add_tail(&master->list, &spi_master_list); + list_for_each_entry(bi, &board_list, list) + spi_match_master_to_boardinfo(master, &bi->board_info); + mutex_unlock(&board_lock); + status = 0; /* Register devices from the device tree */ @@ -579,7 +580,12 @@ void spi_unregister_master(struct spi_master *master) { int dummy; - dummy = device_for_each_child(&master->dev, NULL, __unregister); + mutex_lock(&board_lock); + list_del(&master->list); + mutex_unlock(&board_lock); + + dummy = device_for_each_child(master->dev.parent, &master->dev, + __unregister); device_unregister(&master->dev); } EXPORT_SYMBOL_GPL(spi_unregister_master); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 92e52a1e6af3..b4d7710bc38d 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 @@ -238,6 +239,8 @@ 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, -- GitLab