[PATCH 2/2] fpga: mgr: altera-ps-spi: enable usage on non-dt platforms

[Alan Tull]

From: Anatolij Gustschin <agust@xxxxxxx>

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 <agust@xxxxxxx>
Acked-by: Alan Tull <atull@xxxxxxxxxx>
---
 drivers/fpga/altera-ps-spi.c | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/drivers/fpga/altera-ps-spi.c b/drivers/fpga/altera-ps-spi.c
index 33aafda..8c18bee 100644
--- a/drivers/fpga/altera-ps-spi.c
+++ b/drivers/fpga/altera-ps-spi.c
@@ -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);
-- 
2.7.4