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 spi ids with device names and matching driver data as an index of a map array with data for supported devices. Add this map array and a function for mapping spi ids to driver data. This allows driver binding to dynamically added PS-SPI devices (e.g. when added via spi_new_device() after hot-plugging).

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

---
Changes in v5:
- reword commit message

Changes in v4:
- reword commit message to describe code changes
- rework mapping code as suggested by Alan
- add comment about index with driver data map

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 | 40 +++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

drivers/fpga/altera-ps-spi.c +35 -6

index 33aafda50af5..8c18beec6b57 100644
@@ -75,6 +75,12 @@ static struct altera_ps_data a10_data = {
        .t_st2ck_us = 10, /* min(t_ST2CK) */
 };
 
+/* Array index is enum altera_ps_devtype */
+static const struct altera_ps_data *altera_ps_data_map[] = {
+       &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 },

@@ -234,6 +240,22 @@ static const struct fpga_manager_ops altera_ps_ops = {
        .write_complete = altera_ps_write_complete,
 };
 
+static const struct altera_ps_data *id_to_data(const struct spi_device_id *id)
+{
+       kernel_ulong_t devtype = id->driver_data;
+       const struct altera_ps_data *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;
+}
+
 static int altera_ps_probe(struct spi_device *spi)
 {
        struct altera_ps_conf *conf;

@@ -244,11 +266,17 @@ 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 +322,9 @@ 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