[PATCH 3/3] eeprom/of: Add device tree bindings to at25.

[David Daney <ddaney.cavm@gmail.com>]

From: David Daney <david.daney@cavium.com>

We can extract the "pagesize", "size" and "address-width" from the
device tree so that SPI eeproms can be fully specified in the device
tree.

Also add a MODULE_DEVICE_TABLE so the drivers can be automatically bound.

Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Axel Lin <axel.lin@gmail.com>
---
 drivers/misc/eeprom/at25.c |   61 +++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 01ab3c9..609ee72 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -16,6 +16,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/sched.h>
+#include <linux/of.h>
 
 #include <linux/spi/spi.h>
 #include <linux/spi/eeprom.h>
@@ -293,6 +294,9 @@ static int at25_probe(struct spi_device *spi)
 {
 	struct at25_data	*at25 = NULL;
 	const struct spi_eeprom *chip;
+#ifdef CONFIG_OF
+	struct spi_eeprom of_chip;
+#endif
 	int			err;
 	int			sr;
 	int			addrlen;
@@ -300,9 +304,51 @@ static int at25_probe(struct spi_device *spi)
 	/* Chip description */
 	chip = spi->dev.platform_data;
 	if (!chip) {
-		dev_dbg(&spi->dev, "no chip description\n");
-		err = -ENODEV;
-		goto fail;
+#ifdef CONFIG_OF
+		if (spi->dev.of_node) {
+			u32 val;
+			memset(&of_chip, 0, sizeof(of_chip));
+			if (of_property_read_u32(spi->dev.of_node, "pagesize", &val)) {
+				dev_dbg(&spi->dev, "no \"pagesize\" property\n");
+				err = -ENODEV;
+				goto fail;
+			}
+			of_chip.page_size = val;
+			if (of_property_read_u32(spi->dev.of_node, "size", &val)) {
+				dev_dbg(&spi->dev, "no \"size\" property\n");
+				err = -ENODEV;
+				goto fail;
+			}
+			of_chip.byte_len = val;
+			if (of_property_read_u32(spi->dev.of_node, "address-width", &val)) {
+				dev_dbg(&spi->dev, "no \"address-width\" property\n");
+				err = -ENODEV;
+				goto fail;
+			}
+			switch (val) {
+			case 8:
+				of_chip.flags |= EE_ADDR1;
+				break;
+			case 16:
+				of_chip.flags |= EE_ADDR2;
+				break;
+			case 24:
+				of_chip.flags |= EE_ADDR3;
+				break;
+			default:
+				dev_dbg(&spi->dev, "bad \"address-width\" property: %u\n", val);
+				err = -EINVAL;
+				goto fail;
+			}
+			strlcpy(of_chip.name, spi->dev.of_node->name, sizeof(of_chip.name));
+			chip = &of_chip;
+		} else
+#endif
+		{
+			dev_dbg(&spi->dev, "no chip description\n");
+			err = -ENODEV;
+			goto fail;
+		}
 	}
 
 	/* For now we only support 8/16/24 bit addressing */
@@ -396,11 +442,19 @@ static int __devexit at25_remove(struct spi_device *spi)
 
 /*-------------------------------------------------------------------------*/
 
+static const struct spi_device_id at25_id[] = {
+	{"at25", 0},
+	{"m95256", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, at25_id);
+
 static struct spi_driver at25_driver = {
 	.driver = {
 		.name		= "at25",
 		.owner		= THIS_MODULE,
 	},
+	.id_table	= at25_id,
 	.probe		= at25_probe,
 	.remove		= __devexit_p(at25_remove),
 };
@@ -410,4 +464,3 @@ module_spi_driver(at25_driver);
 MODULE_DESCRIPTION("Driver for most SPI EEPROMs");
 MODULE_AUTHOR("David Brownell");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("spi:at25");
-- 
1.7.2.3