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dm: spi: Check cs number before accessing slaves

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Add chip select number check in spi_find_chip_select().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # SoPine
This commit is contained in:
Bin Meng 2019-09-09 06:00:02 -07:00 committed by Jagan Teki
parent 383fded70c
commit 7bacce524d
2 changed files with 28 additions and 20 deletions
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45
drivers/spi/spi-uclass.c
View File

@ -224,7 +224,32 @@ int spi_chip_select(struct udevice *dev)
int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
{
struct dm_spi_ops *ops;
struct spi_cs_info info;
struct udevice *dev;
int ret;
/*
* Ask the driver. For the moment we don't have CS info.
* When we do we could provide the driver with a helper function
* to figure out what chip selects are valid, or just handle the
* request.
*/
ops = spi_get_ops(bus);
if (ops->cs_info) {
ret = ops->cs_info(bus, cs, &info);
} else {
/*
* We could assume there is at least one valid chip select.
* The driver didn't care enough to tell us.
*/
ret = 0;
}
if (ret) {
printf("Invalid cs %d (err=%d)\n", cs, ret);
return ret;
}
for (device_find_first_child(bus, &dev); dev;
device_find_next_child(&dev)) {
@ -259,7 +284,6 @@ int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
{
struct spi_cs_info local_info;
struct dm_spi_ops *ops;
int ret;
if (!info)
@ -268,24 +292,7 @@ int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
/* If there is a device attached, return it */
info->dev = NULL;
ret = spi_find_chip_select(bus, cs, &info->dev);
if (!ret)
return 0;
/*
* Otherwise ask the driver. For the moment we don't have CS info.
* When we do we could provide the driver with a helper function
* to figure out what chip selects are valid, or just handle the
* request.
*/
ops = spi_get_ops(bus);
if (ops->cs_info)
return ops->cs_info(bus, cs, info);
/*
* We could assume there is at least one valid chip select.
* The driver didn't care enough to tell us.
*/
return 0;
return ret == -ENODEV ? 0 : ret;
}
int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,

3
include/spi.h
View File

@ -561,7 +561,8 @@ int spi_chip_select(struct udevice *slave);
* @bus: SPI bus to search
* @cs: Chip select to look for
* @devp: Returns the slave device if found
* @return 0 if found, -ENODEV on error
* @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached,
* other -ve value on error
*/
int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);