From 3f07af494dfa6de43137dae430431c9fbf929c0c Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 25 Jul 2008 22:25:13 -0400 Subject: [PATCH 1/3] of: adapt of_find_i2c_driver() to be usable by SPI also SPI has a similar problem as I2C in that it needs to determine an appropriate modalias value for each device node. This patch adapts the of_i2c of_find_i2c_driver() function to be usable by of_spi also. Signed-off-by: Grant Likely --- drivers/of/base.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ drivers/of/of_i2c.c | 64 ++------------------------------- include/linux/of.h | 1 + 3 files changed, 92 insertions(+), 61 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 23ffb7c0caf2..ad8ac1a8af28 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -385,3 +385,91 @@ struct device_node *of_find_matching_node(struct device_node *from, return np; } EXPORT_SYMBOL(of_find_matching_node); + +/** + * of_modalias_table: Table of explicit compatible ==> modalias mappings + * + * This table allows particulare compatible property values to be mapped + * to modalias strings. This is useful for busses which do not directly + * understand the OF device tree but are populated based on data contained + * within the device tree. SPI and I2C are the two current users of this + * table. + * + * In most cases, devices do not need to be listed in this table because + * the modalias value can be derived directly from the compatible table. + * However, if for any reason a value cannot be derived, then this table + * provides a method to override the implicit derivation. + * + * At the moment, a single table is used for all bus types because it is + * assumed that the data size is small and that the compatible values + * should already be distinct enough to differentiate between SPI, I2C + * and other devices. + */ +struct of_modalias_table { + char *of_device; + char *modalias; +}; +static struct of_modalias_table of_modalias_table[] = { + /* Empty for now; add entries as needed */ +}; + +/** + * of_modalias_node - Lookup appropriate modalias for a device node + * @node: pointer to a device tree node + * @modalias: Pointer to buffer that modalias value will be copied into + * @len: Length of modalias value + * + * Based on the value of the compatible property, this routine will determine + * an appropriate modalias value for a particular device tree node. Three + * separate methods are used to derive a modalias value. + * + * First method is to lookup the compatible value in of_modalias_table. + * Second is to look for a "linux," entry in the compatible list + * and used that for modalias. Third is to strip off the manufacturer + * prefix from the first compatible entry and use the remainder as modalias + * + * This routine returns 0 on success + */ +int of_modalias_node(struct device_node *node, char *modalias, int len) +{ + int i, cplen; + const char *compatible; + const char *p; + + /* 1. search for exception list entry */ + for (i = 0; i < ARRAY_SIZE(of_modalias_table); i++) { + compatible = of_modalias_table[i].of_device; + if (!of_device_is_compatible(node, compatible)) + continue; + strlcpy(modalias, of_modalias_table[i].modalias, len); + return 0; + } + + compatible = of_get_property(node, "compatible", &cplen); + if (!compatible) + return -ENODEV; + + /* 2. search for linux, entry */ + p = compatible; + while (cplen > 0) { + if (!strncmp(p, "linux,", 6)) { + p += 6; + strlcpy(modalias, p, len); + return 0; + } + + i = strlen(p) + 1; + p += i; + cplen -= i; + } + + /* 3. take first compatible entry and strip manufacturer */ + p = strchr(compatible, ','); + if (!p) + return -ENODEV; + p++; + strlcpy(modalias, p, len); + return 0; +} +EXPORT_SYMBOL_GPL(of_modalias_node); + diff --git a/drivers/of/of_i2c.c b/drivers/of/of_i2c.c index 344e1b03dd8b..6a98dc8aa30b 100644 --- a/drivers/of/of_i2c.c +++ b/drivers/of/of_i2c.c @@ -16,62 +16,6 @@ #include #include -struct i2c_driver_device { - char *of_device; - char *i2c_type; -}; - -static struct i2c_driver_device i2c_devices[] = { -}; - -static int of_find_i2c_driver(struct device_node *node, - struct i2c_board_info *info) -{ - int i, cplen; - const char *compatible; - const char *p; - - /* 1. search for exception list entry */ - for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) { - if (!of_device_is_compatible(node, i2c_devices[i].of_device)) - continue; - if (strlcpy(info->type, i2c_devices[i].i2c_type, - I2C_NAME_SIZE) >= I2C_NAME_SIZE) - return -ENOMEM; - - return 0; - } - - compatible = of_get_property(node, "compatible", &cplen); - if (!compatible) - return -ENODEV; - - /* 2. search for linux, entry */ - p = compatible; - while (cplen > 0) { - if (!strncmp(p, "linux,", 6)) { - p += 6; - if (strlcpy(info->type, p, - I2C_NAME_SIZE) >= I2C_NAME_SIZE) - return -ENOMEM; - return 0; - } - - i = strlen(p) + 1; - p += i; - cplen -= i; - } - - /* 3. take fist compatible entry and strip manufacturer */ - p = strchr(compatible, ','); - if (!p) - return -ENODEV; - p++; - if (strlcpy(info->type, p, I2C_NAME_SIZE) >= I2C_NAME_SIZE) - return -ENOMEM; - return 0; -} - void of_register_i2c_devices(struct i2c_adapter *adap, struct device_node *adap_node) { @@ -83,6 +27,9 @@ void of_register_i2c_devices(struct i2c_adapter *adap, const u32 *addr; int len; + if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) + continue; + addr = of_get_property(node, "reg", &len); if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) { printk(KERN_ERR @@ -92,11 +39,6 @@ void of_register_i2c_devices(struct i2c_adapter *adap, info.irq = irq_of_parse_and_map(node, 0); - if (of_find_i2c_driver(node, &info) < 0) { - irq_dispose_mapping(info.irq); - continue; - } - info.addr = *addr; request_module(info.type); diff --git a/include/linux/of.h b/include/linux/of.h index 59a61bdc98b6..79886ade070f 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -70,5 +70,6 @@ extern int of_n_addr_cells(struct device_node *np); extern int of_n_size_cells(struct device_node *np); extern const struct of_device_id *of_match_node( const struct of_device_id *matches, const struct device_node *node); +extern int of_modalias_node(struct device_node *node, char *modalias, int len); #endif /* _LINUX_OF_H */ From dc87c98e8f635a718f1abb2c3e15fc77c0001651 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Thu, 15 May 2008 16:50:22 -0600 Subject: [PATCH 2/3] spi: split up spi_new_device() to allow two stage registration. spi_new_device() allocates and registers an spi device all in one swoop. If the driver needs to add extra data to the spi_device before it is registered, then this causes problems. This is needed for OF device tree support so that the SPI device tree helper can add a pointer to the device node after the device is allocated, but before the device is registered. OF aware SPI devices can then retrieve data out of the device node to populate a platform data structure. This patch splits the allocation and registration portions of code out of spi_new_device() and creates two new functions; spi_alloc_device() and spi_register_device(). spi_new_device() is modified to use the new functions for allocation and registration. None of the existing users of spi_new_device() should be affected by this change. Drivers using the new API can forego the use of spi_board_info structure to describe the device layout and populate data into the spi_device structure directly. This change is in preparation for adding an OF device tree parser to generate spi_devices based on data in the device tree. Signed-off-by: Grant Likely Acked-by: David Brownell --- drivers/spi/spi.c | 139 +++++++++++++++++++++++++++------------- include/linux/spi/spi.h | 12 ++++ 2 files changed, 107 insertions(+), 44 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ecca4a6a6f94..964124b60db2 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -178,6 +178,96 @@ struct boardinfo { static LIST_HEAD(board_list); static DEFINE_MUTEX(board_lock); +/** + * spi_alloc_device - Allocate a new SPI device + * @master: Controller to which device is connected + * Context: can sleep + * + * Allows a driver to allocate and initialize a spi_device without + * registering it immediately. This allows a driver to directly + * fill the spi_device with device parameters before calling + * spi_add_device() on it. + * + * Caller is responsible to call spi_add_device() on the returned + * spi_device structure to add it to the SPI master. If the caller + * needs to discard the spi_device without adding it, then it should + * call spi_dev_put() on it. + * + * Returns a pointer to the new device, or NULL. + */ +struct spi_device *spi_alloc_device(struct spi_master *master) +{ + struct spi_device *spi; + struct device *dev = master->dev.parent; + + if (!spi_master_get(master)) + return NULL; + + spi = kzalloc(sizeof *spi, GFP_KERNEL); + if (!spi) { + dev_err(dev, "cannot alloc spi_device\n"); + spi_master_put(master); + return NULL; + } + + spi->master = master; + spi->dev.parent = dev; + spi->dev.bus = &spi_bus_type; + spi->dev.release = spidev_release; + device_initialize(&spi->dev); + return spi; +} +EXPORT_SYMBOL_GPL(spi_alloc_device); + +/** + * spi_add_device - Add spi_device allocated with spi_alloc_device + * @spi: spi_device to register + * + * Companion function to spi_alloc_device. Devices allocated with + * spi_alloc_device can be added onto the spi bus with this function. + * + * Returns 0 on success; non-zero on failure + */ +int spi_add_device(struct spi_device *spi) +{ + struct device *dev = spi->master->dev.parent; + int status; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= spi->master->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", + spi->chip_select, + spi->master->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + snprintf(spi->dev.bus_id, sizeof spi->dev.bus_id, + "%s.%u", spi->master->dev.bus_id, + spi->chip_select); + + /* drivers may modify this initial i/o setup */ + status = spi->master->setup(spi); + if (status < 0) { + dev_err(dev, "can't %s %s, status %d\n", + "setup", spi->dev.bus_id, status); + return status; + } + + /* driver core catches callers that misbehave by defining + * devices that already exist. + */ + status = device_add(&spi->dev); + if (status < 0) { + dev_err(dev, "can't %s %s, status %d\n", + "add", spi->dev.bus_id, status); + return status; + } + + dev_dbg(dev, "registered child %s\n", spi->dev.bus_id); + return 0; +} +EXPORT_SYMBOL_GPL(spi_add_device); /** * spi_new_device - instantiate one new SPI device @@ -197,7 +287,6 @@ struct spi_device *spi_new_device(struct spi_master *master, struct spi_board_info *chip) { struct spi_device *proxy; - struct device *dev = master->dev.parent; int status; /* NOTE: caller did any chip->bus_num checks necessary. @@ -207,66 +296,28 @@ struct spi_device *spi_new_device(struct spi_master *master, * suggests syslogged diagnostics are best here (ugh). */ - /* Chipselects are numbered 0..max; validate. */ - if (chip->chip_select >= master->num_chipselect) { - dev_err(dev, "cs%d > max %d\n", - chip->chip_select, - master->num_chipselect); - return NULL; - } - - if (!spi_master_get(master)) + proxy = spi_alloc_device(master); + if (!proxy) return NULL; WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); - proxy = kzalloc(sizeof *proxy, GFP_KERNEL); - if (!proxy) { - dev_err(dev, "can't alloc dev for cs%d\n", - chip->chip_select); - goto fail; - } - proxy->master = master; proxy->chip_select = chip->chip_select; proxy->max_speed_hz = chip->max_speed_hz; proxy->mode = chip->mode; proxy->irq = chip->irq; strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias)); - - snprintf(proxy->dev.bus_id, sizeof proxy->dev.bus_id, - "%s.%u", master->dev.bus_id, - chip->chip_select); - proxy->dev.parent = dev; - proxy->dev.bus = &spi_bus_type; proxy->dev.platform_data = (void *) chip->platform_data; proxy->controller_data = chip->controller_data; proxy->controller_state = NULL; - proxy->dev.release = spidev_release; - /* drivers may modify this initial i/o setup */ - status = master->setup(proxy); + status = spi_add_device(proxy); if (status < 0) { - dev_err(dev, "can't %s %s, status %d\n", - "setup", proxy->dev.bus_id, status); - goto fail; + spi_dev_put(proxy); + return NULL; } - /* driver core catches callers that misbehave by defining - * devices that already exist. - */ - status = device_register(&proxy->dev); - if (status < 0) { - dev_err(dev, "can't %s %s, status %d\n", - "add", proxy->dev.bus_id, status); - goto fail; - } - dev_dbg(dev, "registered child %s\n", proxy->dev.bus_id); return proxy; - -fail: - spi_master_put(master); - kfree(proxy); - return NULL; } EXPORT_SYMBOL_GPL(spi_new_device); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a9cc29d46653..4be01bb44377 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -778,7 +778,19 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n) * use spi_new_device() to describe each device. You can also call * spi_unregister_device() to start making that device vanish, but * normally that would be handled by spi_unregister_master(). + * + * You can also use spi_alloc_device() and spi_add_device() to use a two + * stage registration sequence for each spi_device. This gives the caller + * some more control over the spi_device structure before it is registered, + * but requires that caller to initialize fields that would otherwise + * be defined using the board info. */ +extern struct spi_device * +spi_alloc_device(struct spi_master *master); + +extern int +spi_add_device(struct spi_device *spi); + extern struct spi_device * spi_new_device(struct spi_master *, struct spi_board_info *); From 284b01897340974000bcc84de87a4e1becc8a83d Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Fri, 16 May 2008 11:37:09 -0600 Subject: [PATCH 3/3] spi: Add OF binding support for SPI busses This patch adds support for populating an SPI bus based on data in the OF device tree. This is useful for powerpc platforms which use the device tree instead of discrete code for describing platform layout. Signed-off-by: Grant Likely --- drivers/of/Kconfig | 6 +++ drivers/of/Makefile | 1 + drivers/of/of_spi.c | 93 ++++++++++++++++++++++++++++++++++++++++++ include/linux/of_spi.h | 18 ++++++++ 4 files changed, 118 insertions(+) create mode 100644 drivers/of/of_spi.c create mode 100644 include/linux/of_spi.h diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 1d7ec3129349..f821dbc952a4 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -13,3 +13,9 @@ config OF_I2C depends on PPC_OF && I2C help OpenFirmware I2C accessors + +config OF_SPI + def_tristate SPI + depends on OF && PPC_OF && SPI + help + OpenFirmware SPI accessors diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 548772e871fd..4c3c6f8e36f5 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -2,3 +2,4 @@ obj-y = base.o obj-$(CONFIG_OF_DEVICE) += device.o platform.o obj-$(CONFIG_OF_GPIO) += gpio.o obj-$(CONFIG_OF_I2C) += of_i2c.o +obj-$(CONFIG_OF_SPI) += of_spi.o diff --git a/drivers/of/of_spi.c b/drivers/of/of_spi.c new file mode 100644 index 000000000000..b01eec026f68 --- /dev/null +++ b/drivers/of/of_spi.c @@ -0,0 +1,93 @@ +/* + * SPI OF support routines + * Copyright (C) 2008 Secret Lab Technologies Ltd. + * + * Support routines for deriving SPI device attachments from the device + * tree. + */ + +#include +#include +#include +#include + +/** + * of_register_spi_devices - Register child devices onto the SPI bus + * @master: Pointer to spi_master device + * @np: parent node of SPI device nodes + * + * Registers an spi_device for each child node of 'np' which has a 'reg' + * property. + */ +void of_register_spi_devices(struct spi_master *master, struct device_node *np) +{ + struct spi_device *spi; + struct device_node *nc; + const u32 *prop; + int rc; + int len; + + for_each_child_of_node(np, nc) { + /* Alloc an spi_device */ + spi = spi_alloc_device(master); + if (!spi) { + dev_err(&master->dev, "spi_device alloc error for %s\n", + nc->full_name); + spi_dev_put(spi); + continue; + } + + /* Select device driver */ + if (of_modalias_node(nc, spi->modalias, + sizeof(spi->modalias)) < 0) { + dev_err(&master->dev, "cannot find modalias for %s\n", + nc->full_name); + spi_dev_put(spi); + continue; + } + + /* Device address */ + prop = of_get_property(nc, "reg", &len); + if (!prop || len < sizeof(*prop)) { + dev_err(&master->dev, "%s has no 'reg' property\n", + nc->full_name); + spi_dev_put(spi); + continue; + } + spi->chip_select = *prop; + + /* Mode (clock phase/polarity/etc.) */ + if (of_find_property(nc, "spi-cpha", NULL)) + spi->mode |= SPI_CPHA; + if (of_find_property(nc, "spi-cpol", NULL)) + spi->mode |= SPI_CPOL; + + /* Device speed */ + prop = of_get_property(nc, "spi-max-frequency", &len); + if (!prop || len < sizeof(*prop)) { + dev_err(&master->dev, "%s has no 'spi-max-frequency' property\n", + nc->full_name); + spi_dev_put(spi); + continue; + } + spi->max_speed_hz = *prop; + + /* IRQ */ + spi->irq = irq_of_parse_and_map(nc, 0); + + /* Store a pointer to the node in the device structure */ + of_node_get(nc); + spi->dev.archdata.of_node = nc; + + /* Register the new device */ + request_module(spi->modalias); + rc = spi_add_device(spi); + if (rc) { + dev_err(&master->dev, "spi_device register error %s\n", + nc->full_name); + spi_dev_put(spi); + } + + } +} +EXPORT_SYMBOL(of_register_spi_devices); diff --git a/include/linux/of_spi.h b/include/linux/of_spi.h new file mode 100644 index 000000000000..5f71ee8c0868 --- /dev/null +++ b/include/linux/of_spi.h @@ -0,0 +1,18 @@ +/* + * OpenFirmware SPI support routines + * Copyright (C) 2008 Secret Lab Technologies Ltd. + * + * Support routines for deriving SPI device attachments from the device + * tree. + */ + +#ifndef __LINUX_OF_SPI_H +#define __LINUX_OF_SPI_H + +#include +#include + +extern void of_register_spi_devices(struct spi_master *master, + struct device_node *np); + +#endif /* __LINUX_OF_SPI */