With this patch spi drivers can use standard spi_driver.id_table and
MODULE_DEVICE_TABLE() mechanisms to bind against the devices. Just
like we do with I2C drivers.
This is useful when a single driver supports several variants of
devices but it is not possible to detect them in run-time (like
non-JEDEC chips probing in drivers/mtd/devices/m25p80.c), and
when platform_data usage is overkill.
This patch also makes life a lot easier on OpenFirmware platforms,
since with OF we extensively use proper device IDs in modaliases.
Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
---
drivers/spi/spi.c | 26 +++++++++++++++++++++++++-
include/linux/mod_devicetable.h | 13 +++++++++++++
include/linux/spi/spi.h | 10 ++++++++--
scripts/mod/file2alias.c | 13 +++++++++++++
4 files changed, 59 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 70845cc..1431bf2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -59,9 +59,24 @@ static struct device_attribute spi_dev_attrs[] = {
* and the sysfs version makes coldplug work too.
*/
+static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
+ const struct spi_device *sdev)
+{
+ while (id->name[0]) {
+ if (!strcmp(sdev->modalias, id->name))
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
static int spi_match_device(struct device *dev, struct device_driver *drv)
{
const struct spi_device *spi = to_spi_device(dev);
+ const struct spi_driver *sdrv = to_spi_driver(drv);
+
+ if (sdrv->id_table)
+ return !!spi_match_id(sdrv->id_table, spi);
return strcmp(spi->modalias, drv->name) == 0;
}
@@ -121,6 +136,13 @@ struct bus_type spi_bus_type = {
};
EXPORT_SYMBOL_GPL(spi_bus_type);
+static int spi_drv_probe_id(struct device *dev)
+{
+ const struct spi_driver *sdrv = to_spi_driver(dev->driver);
+ struct spi_device *sdev = to_spi_device(dev);
+
+ return sdrv->probe_id(sdev, spi_match_id(sdrv->id_table, sdev));
+}
static int spi_drv_probe(struct device *dev)
{
@@ -151,7 +173,9 @@ static void spi_drv_shutdown(struct device *dev)
int spi_register_driver(struct spi_driver *sdrv)
{
sdrv->driver.bus = &spi_bus_type;
- if (sdrv->probe)
+ if (sdrv->probe_id)
+ sdrv->driver.probe = spi_drv_probe_id;
+ else if (sdrv->probe)
sdrv->driver.probe = spi_drv_probe;
if (sdrv->remove)
sdrv->driver.remove = spi_drv_remove;
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 1bf5900..9660dca 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -399,6 +399,19 @@ struct i2c_device_id {
__attribute__((aligned(sizeof(kernel_ulong_t))));
};
+/* spi */
+
+#define SPI_NAME_SIZE 20
+
+struct spi_device_id {
+ char name[SPI_NAME_SIZE];
+#ifdef __KERNEL__
+ void *data;
+#else
+ kernel_ulong_t data;
+#endif
+};
+
/* dmi */
enum dmi_field {
DMI_NONE,
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index c47c4b4..c8d92a1 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -20,6 +20,7 @@
#define __LINUX_SPI_H
#include <linux/device.h>
+#include <linux/mod_devicetable.h>
/*
* INTERFACES between SPI master-side drivers and SPI infrastructure.
@@ -86,7 +87,7 @@ struct spi_device {
int irq;
void *controller_state;
void *controller_data;
- char modalias[32];
+ char modalias[SPI_NAME_SIZE];
/*
* likely need more hooks for more protocol options affecting how
@@ -145,6 +146,8 @@ struct spi_message;
/**
* struct spi_driver - Host side "protocol" driver
+ * @id_table: List of SPI devices supported by this driver
+ * @probe_id: Binds this driver to the spi device via id_table matching.
* @probe: Binds this driver to the spi device. Drivers can verify
* that the device is actually present, and may need to configure
* characteristics (such as bits_per_word) which weren't needed for
@@ -170,6 +173,9 @@ struct spi_message;
* MMC, RTC, filesystem character device nodes, and hardware monitoring.
*/
struct spi_driver {
+ const struct spi_device_id *id_table;
+ int (*probe_id)(struct spi_device *spi,
+ const struct spi_device_id *id);
int (*probe)(struct spi_device *spi);
int (*remove)(struct spi_device *spi);
void (*shutdown)(struct spi_device *spi);
@@ -732,7 +738,7 @@ struct spi_board_info {
* controller_data goes to spi_device.controller_data,
* irq is copied too
*/
- char modalias[32];
+ char modalias[SPI_NAME_SIZE];
const void *platform_data;
void *controller_data;
int irq;
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 40e0045..9d446e3 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -657,6 +657,15 @@ static int do_i2c_entry(const char *filename, struct i2c_device_id *id,
return 1;
}
+/* Looks like: S */
+static int do_spi_entry(const char *filename, struct spi_device_id *id,
+ char *alias)
+{
+ sprintf(alias, "%s", id->name);
+
+ return 1;
+}
+
static const struct dmifield {
const char *prefix;
int field;
@@ -853,6 +862,10 @@ void handle_moddevtable(struct module *mod, struct elf_info *info,
do_table(symval, sym->st_size,
sizeof(struct i2c_device_id), "i2c",
do_i2c_entry, mod);
+ else if (sym_is(symname, "__mod_spi_device_table"))
+ do_table(symval, sym->st_size,
+ sizeof(struct spi_device_id), "spi",
+ do_spi_entry, mod);
else if (sym_is(symname, "__mod_dmi_device_table"))
do_table(symval, sym->st_size,
sizeof(struct dmi_system_id), "dmi",
--
1.6.3.3
