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spi: fsi: Check mux status before transfers

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The SPI controllers are not accessible if the mux isn't set. Therefore,
check the mux status before starting a transfer and fail out if it isn't
set.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20200909222857.28653-7-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Eddie James 2020-09-09 17:28:57 -05:00 committed by Mark Brown
parent 49c9fc1d7c
commit 9211a441e6
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 27 additions and 13 deletions
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40
drivers/spi/spi-fsi.c
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@ -12,6 +12,7 @@
#define FSI_ENGID_SPI 0x23
#define FSI_MBOX_ROOT_CTRL_8 0x2860
#define FSI_MBOX_ROOT_CTRL_8_SPI_MUX 0xf0000000
#define FSI2SPI_DATA0 0x00
#define FSI2SPI_DATA1 0x04
@ -84,6 +85,26 @@ struct fsi_spi_sequence {
u64 data;
};
static int fsi_spi_check_mux(struct fsi_device *fsi, struct device *dev)
{
int rc;
u32 root_ctrl_8;
__be32 root_ctrl_8_be;
rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8_be,
sizeof(root_ctrl_8_be));
if (rc)
return rc;
root_ctrl_8 = be32_to_cpu(root_ctrl_8_be);
dev_dbg(dev, "Root control register 8: %08x\n", root_ctrl_8);
if ((root_ctrl_8 & FSI_MBOX_ROOT_CTRL_8_SPI_MUX) ==
FSI_MBOX_ROOT_CTRL_8_SPI_MUX)
return 0;
return -ENOLINK;
}
static int fsi_spi_check_status(struct fsi_spi *ctx)
{
int rc;
@ -449,11 +470,15 @@ static int fsi_spi_transfer_init(struct fsi_spi *ctx)
static int fsi_spi_transfer_one_message(struct spi_controller *ctlr,
struct spi_message *mesg)
{
int rc = 0;
int rc;
u8 seq_slave = SPI_FSI_SEQUENCE_SEL_SLAVE(mesg->spi->chip_select + 1);
struct spi_transfer *transfer;
struct fsi_spi *ctx = spi_controller_get_devdata(ctlr);
rc = fsi_spi_check_mux(ctx->fsi, ctx->dev);
if (rc)
return rc;
list_for_each_entry(transfer, &mesg->transfers, transfer_list) {
struct fsi_spi_sequence seq;
struct spi_transfer *next = NULL;
@ -537,24 +562,13 @@ static size_t fsi_spi_max_transfer_size(struct spi_device *spi)
static int fsi_spi_probe(struct device *dev)
{
int rc;
u32 root_ctrl_8;
struct device_node *np;
int num_controllers_registered = 0;
struct fsi_device *fsi = to_fsi_dev(dev);
/*
* Check the SPI mux before attempting to probe. If the mux isn't set
* then the SPI controllers can't access their slave devices.
*/
rc = fsi_slave_read(fsi->slave, FSI_MBOX_ROOT_CTRL_8, &root_ctrl_8,
sizeof(root_ctrl_8));
rc = fsi_spi_check_mux(fsi, dev);
if (rc)
return rc;
if (!root_ctrl_8) {
dev_dbg(dev, "SPI mux not set, aborting probe.\n");
return -ENODEV;
}
for_each_available_child_of_node(dev->of_node, np) {
u32 base;