From: Eddie James <eajames@linux.ibm.com>
To: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
eajames@linux.ibm.com, joel@jms.id.au,
bradleyb@fuzziesquirrel.com, broonie@kernel.org,
robh+dt@kernel.org, arnd@arndb.de
Subject: [PATCH 6/7] spi: fsi: Check mux status before transfers
Date: Thu, 20 Aug 2020 12:02:27 -0500 [thread overview]
Message-ID: <20200820170228.42053-7-eajames@linux.ibm.com> (raw)
In-Reply-To: <20200820170228.42053-1-eajames@linux.ibm.com>
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>
---
drivers/spi/spi-fsi.c | 40 +++++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 13 deletions(-)
diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c
index 53cfa201e187..9c0a4413ec3d 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;
--
2.26.2
next prev parent reply other threads:[~2020-08-20 17:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 17:02 [PATCH 0/7] spi: Fix FSI-attached controller and AT25 drivers Eddie James
2020-08-20 17:02 ` [PATCH 1/7] spi: fsi: Handle 9 to 15 byte transfers lengths Eddie James
2020-08-20 17:02 ` [PATCH 2/7] spi: fsi: Fix clock running too fast Eddie James
2020-08-20 17:12 ` Mark Brown
2020-08-20 21:06 ` Eddie James
2020-08-25 7:10 ` Joel Stanley
2020-08-20 17:02 ` [PATCH 3/7] spi: fsi: Fix use of the bneq+ sequencer instruction Eddie James
2020-08-20 17:02 ` [PATCH 4/7] dt-bindings: fsi: fsi2spi: Document new restricted property Eddie James
2020-08-20 17:14 ` Mark Brown
2020-08-20 21:07 ` Eddie James
2020-08-21 12:03 ` Mark Brown
2020-09-08 20:44 ` Rob Herring
2020-08-20 17:02 ` [PATCH 5/7] spi: fsi: Implement restricted size for certain controllers Eddie James
2020-08-20 17:19 ` Mark Brown
2020-08-20 17:02 ` Eddie James [this message]
2020-08-20 17:02 ` [PATCH 7/7] eeprom: at25: Split reads into chunks and cap write size Eddie James
2020-08-20 17:20 ` Mark Brown
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