[RESEND PATCH v4 2/2] eeprom: at24: Add support for address-width property

From: alanx . chiang
Date: Tue Jul 24 2018 - 23:21:39 EST


From: Alan Chiang <alanx.chiang@xxxxxxxxx>

Provide a flexible way to determine the addressing bits of eeprom.
Pass the addressing bits to driver through address-width property.

Signed-off-by: Alan Chiang <alanx.chiang@xxxxxxxxx>
Signed-off-by: Andy Yeh <andy.yeh@xxxxxxxxx>
---
drivers/misc/eeprom/at24.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 0c125f2..7ea640b 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -478,6 +478,23 @@ static void at24_properties_to_pdata(struct device *dev,
if (device_property_present(dev, "no-read-rollover"))
chip->flags |= AT24_FLAG_NO_RDROL;

+ err = device_property_read_u32(dev, "address-width", &val);
+ if (!err) {
+ switch (val) {
+ case 8:
+ if (chip->flags & AT24_FLAG_ADDR16)
+ dev_warn(dev, "Override address width to be 8, while default is 16\n");
+ chip->flags &= ~AT24_FLAG_ADDR16;
+ break;
+ case 16:
+ chip->flags |= AT24_FLAG_ADDR16;
+ break;
+ default:
+ dev_warn(dev, "Bad \"address-width\" property: %u\n",
+ val);
+ }
+ }
+
err = device_property_read_u32(dev, "size", &val);
if (!err)
chip->byte_len = val;
--
2.7.4