fpga: mgr: altera-ps-spi: enable usage on non-dt platforms

Driver probing fails on non-dt platforms since of_match_device() always returns NULL here. Add device names and matching driver data to the spi_device_id table. This allows driver binding to dynamically added PS-SPI devices (e.g. added via spi_new_device() after hot-plugging).

Signed-off-by Anatolij Gustschin <[email protected]>

---
Changes in v3:
- don't use pointers to device data struct in driver_data

Driver probing fails on non-dt platforms since of_match_device() always returns NULL here. Add device names and matching driver data to the spi_device_id table. This allows driver binding to dynamically added PS-SPI devices (e.g. added via spi_new_device() after hot-plugging).

Signed-off-by Anatolij Gustschin <[email protected]>

---
Changes in v3:
- don't use pointers to device data struct in driver_data

Changes in v2:
- removed not necessary braces {}
- dropped not needed !id check

 drivers/fpga/altera-ps-spi.c | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

drivers/fpga/altera-ps-spi.c +0 -0

index 33aafda50af5..78d809194b7d 100644

drivers/fpga/altera-ps-spi.c +4 -0

+       &c5_data,
+       &a10_data,
+};
+
 static const struct of_device_id of_ef_match[] = {
        { .compatible = "altr,fpga-passive-serial", .data = &c5_data },
        { .compatible = "altr,fpga-arria10-passive-serial", .data = &a10_data },

drivers/fpga/altera-ps-spi.c +20 -6

+               data = altera_ps_data_map[i];
+               if (data && data->devtype == id->driver_data)
+                       return data;
+       }
+       return NULL;
+}
+
 static int altera_ps_probe(struct spi_device *spi)
 {
        struct altera_ps_conf *conf;

@@ -244,11 +262,17 @@ static int altera_ps_probe(struct spi_device *spi)
        if (!conf)
                return -ENOMEM;
 
-       of_id = of_match_device(of_ef_match, &spi->dev);
-       if (!of_id)
-               return -ENODEV;
+       if (spi->dev.of_node) {
+               of_id = of_match_device(of_ef_match, &spi->dev);
+               if (!of_id)
+                       return -ENODEV;
+               conf->data = of_id->data;
+       } else {
+               conf->data = id_to_data(spi_get_device_id(spi));
+               if (!conf->data)
+                       return -ENODEV;
+       }
 
-       conf->data = of_id->data;
        conf->spi = spi;
        conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW);
        if (IS_ERR(conf->config)) {

@@ -294,7 +318,9 @@ static int altera_ps_remove(struct spi_device *spi)
 }
 
 static const struct spi_device_id altera_ps_spi_ids[] = {
-       {"cyclone-ps-spi", 0},
+       { "cyclone-ps-spi", CYCLONE5 },
+       { "fpga-passive-serial", CYCLONE5 },
+       { "fpga-arria10-passive-serial", ARRIA10 },
        {}
 };
 MODULE_DEVICE_TABLE(spi, altera_ps_spi_ids);
--

2.17.1

Need to update the header to explain what has been added since v2 (added spi ids and an array and code to map spi ids to data).

Quoted 1 line

+static const struct altera_ps_data *altera_ps_data_map[] = {

Please add a comment that array index is enum altera_ps_devtype or something like that. Make it easy for future generations to do the right thing. :)

Quoted 5 lines

drivers/fpga/altera-ps-spi.c +5 -0

+static const struct altera_ps_data *id_to_data(const struct spi_device_id *id)
+{
+       const struct altera_ps_data *data;
+       unsigned int i;
+

Quoted 1 line

+ for (i = 0; i < ARRAY_SIZE(altera_ps_data_map); i++) {

At this point, id->driver_data == CYCLONE5 or ARRIA10 (more added in the future) so we don't need a loop to search the mapping array for a
matching id. Would something like the following work instead of
this for loop? I understand you wanted to do some checking, this accomplishes some checking but will exit NULL if someone extends the array wrongly.

kernel_ulong_t devtype = id->driver_data;

/* someone added a altera_ps_devtype without adding to the map array */ if (devtype >= ARRAY_SIZE(altera_ps_data_map))
return NULL;

data = altera_ps_data_map[devtype];
if (!data || data->devtype != devtype)
return NULL;

return data;