spi: spi-mem: Extend the SPI mem interface to set a custom memory name

When porting (Q)SPI controller drivers from the MTD layer to the SPI
layer, the naming scheme for the memory devices changes. To be able
to keep compatibility with the old drivers naming scheme, a name
field is added to struct spi_mem and a hook is added to let controller
drivers set a custom name for the memory device.

Example for the FSL QSPI driver:

Name with the old driver: 21e0000.qspi,
or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ...

Name with the new driver without spi_mem_get_name: spi4.0

Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 990770dfa5cf..e43842c7a31a 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -311,6 +311,24 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 EXPORT_SYMBOL_GPL(spi_mem_exec_op);
 
 /**
+ * spi_mem_get_name() - Return the SPI mem device name to be used by the
+ *			upper layer if necessary
+ * @mem: the SPI memory
+ *
+ * This function allows SPI mem users to retrieve the SPI mem device name.
+ * It is useful if the upper layer needs to expose a custom name for
+ * compatibility reasons.
+ *
+ * Return: a string containing the name of the memory device to be used
+ *	   by the SPI mem user
+ */
+const char *spi_mem_get_name(struct spi_mem *mem)
+{
+	return mem->name;
+}
+EXPORT_SYMBOL_GPL(spi_mem_get_name);
+
+/**
  * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
  *			      match controller limitations
  * @mem: the SPI memory
@@ -344,6 +362,7 @@ static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv)
 static int spi_mem_probe(struct spi_device *spi)
 {
 	struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver);
+	struct spi_controller *ctlr = spi->controller;
 	struct spi_mem *mem;
 
 	mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL);
@@ -351,6 +370,15 @@ static int spi_mem_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	mem->spi = spi;
+
+	if (ctlr->mem_ops && ctlr->mem_ops->get_name)
+		mem->name = ctlr->mem_ops->get_name(mem);
+	else
+		mem->name = dev_name(&spi->dev);
+
+	if (IS_ERR_OR_NULL(mem->name))
+		return PTR_ERR(mem->name);
+
 	spi_set_drvdata(spi, mem);
 
 	return memdrv->probe(mem);