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| author | Eddie James <eajames@linux.ibm.com> | 2020-09-10 00:28:57 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-09-17 20:31:43 +0200 |
| commit | 9211a441e60686eec2ebd8f7bd65c4f780416404 (patch) | |
| tree | 68885d300b39a1055a49a47d87c5a823453051b1 /drivers/spi/spi-fsi.c | |
| parent | spi: fsi: Implement restricted size for certain controllers (diff) | |
| download | linux-9211a441e60686eec2ebd8f7bd65c4f780416404.tar.xz linux-9211a441e60686eec2ebd8f7bd65c4f780416404.zip | |
spi: fsi: Check mux status before transfers
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>
Diffstat (limited to '')
| -rw-r--r-- | drivers/spi/spi-fsi.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index a702e9d7d68c..8a440c7078ef 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -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; |