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[PATCHv2] i2c: slave-eeprom: Make it possible to pre-load eeprom data

Message ID 20200424090443.26316-1-bjorn.ardo@axis.com
State Accepted
Commit e804f0a78e9e43f0105e1bc3e264894b3898e970
Headers show
Series [PATCHv2] i2c: slave-eeprom: Make it possible to pre-load eeprom data | expand

Commit Message

Bjorn Ardo April 24, 2020, 9:04 a.m. UTC
If the slave eeprom has a "firmware-name" in devicetree, then
pre-load the data in the eeprom with this file. Otherwise we
init the eeprom with 0xFF.

Signed-off-by: Björn Ardö <bjorn.ardo@axis.com>
---
 drivers/i2c/i2c-slave-eeprom.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
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Patch

diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c
index cb415b10642f..c846c96c25c9 100644
--- a/drivers/i2c/i2c-slave-eeprom.c
+++ b/drivers/i2c/i2c-slave-eeprom.c
@@ -18,6 +18,7 @@ 
  */
 
 #include <linux/bitfield.h>
+#include <linux/firmware.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -120,6 +121,26 @@  static ssize_t i2c_slave_eeprom_bin_write(struct file *filp, struct kobject *kob
 	return count;
 }
 
+static int i2c_slave_init_eeprom_data(struct eeprom_data *eeprom, struct i2c_client *client,
+					 unsigned int size)
+{
+	const struct firmware *fw;
+	const char *eeprom_data;
+	int error = device_property_read_string(&client->dev, "firmware-name", &eeprom_data);
+
+	if (!error) {
+		int ret = request_firmware_into_buf(&fw, eeprom_data, &client->dev,
+						    eeprom->buffer, size);
+		if (ret)
+			return ret;
+		release_firmware(fw);
+	} else {
+		/* An empty eeprom typically has all bits set to 1 */
+		memset(eeprom->buffer, 0xFF, size);
+	}
+	return 0;
+}
+
 static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct eeprom_data *eeprom;
@@ -138,6 +159,10 @@  static int i2c_slave_eeprom_probe(struct i2c_client *client, const struct i2c_de
 	spin_lock_init(&eeprom->buffer_lock);
 	i2c_set_clientdata(client, eeprom);
 
+	ret = i2c_slave_init_eeprom_data(eeprom, client, size);
+	if (ret)
+		return ret;
+
 	sysfs_bin_attr_init(&eeprom->bin);
 	eeprom->bin.attr.name = "slave-eeprom";
 	eeprom->bin.attr.mode = S_IRUSR | S_IWUSR;