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From:   Eddie James <eajames@linux.ibm.com>
To:     linux-fsi@lists.ozlabs.org
Cc:     linux-kernel@vger.kernel.org, jk@ozlabs.org, joel@jms.id.au,
        alistair@popple.id.au, andrew@aj.id.au, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        devicetree@vger.kernel.org
Subject: [PATCH 02/14] fsi: Add aliased device numbering
Date:   Mon, 12 Jun 2023 14:56:45 -0500
Message-Id: <20230612195657.245125-3-eajames@linux.ibm.com>
In-Reply-To: <20230612195657.245125-1-eajames@linux.ibm.com>
References: <20230612195657.245125-1-eajames@linux.ibm.com>
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The I2C and SPI subsystems can use an aliased name to number the device.
Add similar support to the FSI subsystem for any device type.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
---
 drivers/fsi/fsi-core.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index d591e68afd11..b77013b9d8a7 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -955,9 +955,34 @@ static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
 	return 0;
 }
 
+static const char *const fsi_dev_type_names[] = {
+	"cfam",
+	"sbefifo",
+	"scom",
+	"occ",
+};
+
 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
 		      dev_t *out_dev, int *out_index)
 {
+	if (fdev->dev.of_node) {
+		int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);
+
+		if (aid >= 0) {
+			int id = (aid << 4) | type;
+
+			id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
+			if (id >= 0) {
+				*out_index = aid;
+				*out_dev = fsi_base_dev + id;
+				return 0;
+			}
+
+			if (id != -ENOSPC)
+				return id;
+		}
+	}
+
 	return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
 }
 EXPORT_SYMBOL_GPL(fsi_get_new_minor);
-- 
2.31.1