From 7bacce524d48594dae399f9ee9280ab105f6c8cf Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Mon, 9 Sep 2019 06:00:02 -0700 Subject: [PATCH] dm: spi: Check cs number before accessing slaves Add chip select number check in spi_find_chip_select(). Signed-off-by: Bin Meng Tested-by: Jagan Teki # SoPine --- drivers/spi/spi-uclass.c | 45 ++++++++++++++++++++++++++------------------- include/spi.h | 3 ++- 2 files changed, 28 insertions(+), 20 deletions(-) diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c index 0ca108e..5ced890 100644 --- a/drivers/spi/spi-uclass.c +++ b/drivers/spi/spi-uclass.c @@ -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, diff --git a/include/spi.h b/include/spi.h index ba2c840..18a0312 100644 --- a/include/spi.h +++ b/include/spi.h @@ -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); -- 2.7.4