misc: at25: Parse dt settings

This adds dt support to the at25 eeprom driver.

Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Tested-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/devicetree/bindings/misc/at25.txt b/Documentation/devicetree/bindings/misc/at25.txt
new file mode 100644 (file)
index 0000000..ab3c327
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/at25.txt
@@ -0,0 +1,21 @@
+Atmel AT25 eeprom
+
+Required properties:
+- compatible : "atmel,at25".
+- reg : chip select number
+- spi-max-frequency : max spi frequency to use
+
+- at25,byte-len : total eeprom size in bytes
+- at25,addr-mode : addr-mode flags, as defined in include/linux/spi/eeprom.h
+- at25,page-size : size of the eeprom page
+
+Examples:
+at25@0 {
+       compatible = "atmel,at25";
+       reg = <0>
+       spi-max-frequency = <5000000>;
+
+       at25,byte-len = <0x8000>;
+       at25,addr-mode = <2>;
+       at25,page-size = <64>;
+};

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 0842c2994ee24d2f2d6d285968bdad054ea52e13..25003d6ceb56f2bca0364c81c881b79dee870711 100644 (file)
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -19,7 +19,7 @@
 
 #include <linux/spi/spi.h>
 #include <linux/spi/eeprom.h>
-
+#include <linux/of.h>
 
 /*
  * NOTE: this is an *EEPROM* driver.  The vagaries of product naming
@@ -305,25 +305,54 @@ static ssize_t at25_mem_write(struct memory_accessor *mem, const char *buf,
 static int at25_probe(struct spi_device *spi)
 {
        struct at25_data        *at25 = NULL;
-       const struct spi_eeprom *chip;
+       struct spi_eeprom       chip;
+       struct device_node      *np = spi->dev.of_node;
        int                     err;
        int                     sr;
        int                     addrlen;
 
        /* Chip description */
-       chip = spi->dev.platform_data;
-       if (!chip) {
-               dev_dbg(&spi->dev, "no chip description\n");
-               err = -ENODEV;
-               goto fail;
-       }
+       if (!spi->dev.platform_data) {
+               if (np) {
+                       u32 val;
+
+                       memset(&chip, 0, sizeof(chip));
+                       strncpy(chip.name, np->name, 10);
+
+                       err = of_property_read_u32(np, "at25,byte-len", &val);
+                       if (err) {
+                               dev_dbg(&spi->dev, "invalid chip dt description\n");
+                               goto fail;
+                       }
+                       chip.byte_len = val;
+
+                       err = of_property_read_u32(np, "at25,addr-mode", &val);
+                       if (err) {
+                               dev_dbg(&spi->dev, "invalid chip dt description\n");
+                               goto fail;
+                       }
+                       chip.flags = (u16)val;
+
+                       err = of_property_read_u32(np, "at25,page-size", &val);
+                       if (err) {
+                               dev_dbg(&spi->dev, "invalid chip dt description\n");
+                               goto fail;
+                       }
+                       chip.page_size = (u16)val;
+               } else {
+                       dev_dbg(&spi->dev, "no chip description\n");
+                       err = -ENODEV;
+                       goto fail;
+               }
+       } else
+               chip = *(struct spi_eeprom *)spi->dev.platform_data;
 
        /* For now we only support 8/16/24 bit addressing */
-       if (chip->flags & EE_ADDR1)
+       if (chip.flags & EE_ADDR1)
                addrlen = 1;
-       else if (chip->flags & EE_ADDR2)
+       else if (chip.flags & EE_ADDR2)
                addrlen = 2;
-       else if (chip->flags & EE_ADDR3)
+       else if (chip.flags & EE_ADDR3)
                addrlen = 3;
        else {
                dev_dbg(&spi->dev, "unsupported address type\n");
@@ -348,7 +377,7 @@ static int at25_probe(struct spi_device *spi)
        }
 
        mutex_init(&at25->lock);
-       at25->chip = *chip;
+       at25->chip = chip;
        at25->spi = spi_dev_get(spi);
        dev_set_drvdata(&spi->dev, at25);
        at25->addrlen = addrlen;
@@ -369,7 +398,7 @@ static int at25_probe(struct spi_device *spi)
        at25->mem.read = at25_mem_read;
 
        at25->bin.size = at25->chip.byte_len;
-       if (!(chip->flags & EE_READONLY)) {
+       if (!(chip.flags & EE_READONLY)) {
                at25->bin.write = at25_bin_write;
                at25->bin.attr.mode |= S_IWUSR;
                at25->mem.write = at25_mem_write;
@@ -379,8 +408,8 @@ static int at25_probe(struct spi_device *spi)
        if (err)
                goto fail;
 
-       if (chip->setup)
-               chip->setup(&at25->mem, chip->context);
+       if (chip.setup)
+               chip.setup(&at25->mem, chip.context);
 
        dev_info(&spi->dev, "%Zd %s %s eeprom%s, pagesize %u\n",
                (at25->bin.size < 1024)
@@ -388,7 +417,7 @@ static int at25_probe(struct spi_device *spi)
                        : (at25->bin.size / 1024),
                (at25->bin.size < 1024) ? "Byte" : "KByte",
                at25->chip.name,
-               (chip->flags & EE_READONLY) ? " (readonly)" : "",
+               (chip.flags & EE_READONLY) ? " (readonly)" : "",
                at25->chip.page_size);
        return 0;
 fail: