[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