bootcount: dm_i2c: Support also single word mode

In addition to pre-existing half-word (2 byte) mode, add support for
the driver to work also in single word (4 byte) mode by adding
'size = <0x4>;' in the device tree node.

Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>

diff --git a/drivers/bootcount/bootcount_dm_i2c.c b/drivers/bootcount/bootcount_dm_i2c.c
index e27034cbeb0d2588e9d060739d319e5ae5034c7f..07359ecfa6c2cce1339f7404add30a78be612988 100644 (file)
--- a/drivers/bootcount/bootcount_dm_i2c.c
+++ b/drivers/bootcount/bootcount_dm_i2c.c
@@ -15,6 +15,7 @@
 struct bootcount_i2c_priv {
        struct udevice *bcdev;
        unsigned int offset;
+       unsigned int size;
 };
 
 static int bootcount_i2c_set(struct udevice *dev, const u32 val)
@@ -22,13 +23,22 @@ static int bootcount_i2c_set(struct udevice *dev, const u32 val)
        int ret;
        struct bootcount_i2c_priv *priv = dev_get_priv(dev);
 
-       ret = dm_i2c_reg_write(priv->bcdev, priv->offset, BC_MAGIC);
-       if (ret < 0)
-               goto err_exit;
-
-       ret = dm_i2c_reg_write(priv->bcdev, priv->offset + 1, val & 0xff);
-       if (ret < 0)
-               goto err_exit;
+       if (priv->size == 4) {
+               u32 bc = (CONFIG_SYS_BOOTCOUNT_MAGIC & BOOTCOUNT_MAGIC_MASK)
+                       | (val & BOOTCOUNT_COUNT_MASK);
+
+               ret = dm_i2c_write(priv->bcdev, priv->offset, (uint8_t *)&bc, sizeof(bc));
+               if (ret < 0)
+                       goto err_exit;
+       } else {
+               ret = dm_i2c_reg_write(priv->bcdev, priv->offset, BC_MAGIC);
+               if (ret < 0)
+                       goto err_exit;
+
+               ret = dm_i2c_reg_write(priv->bcdev, priv->offset + 1, val & 0xff);
+               if (ret < 0)
+                       goto err_exit;
+       }
 
        return 0;
 
@@ -42,21 +52,39 @@ static int bootcount_i2c_get(struct udevice *dev, u32 *val)
        int ret;
        struct bootcount_i2c_priv *priv = dev_get_priv(dev);
 
-       ret = dm_i2c_reg_read(priv->bcdev, priv->offset);
-       if (ret < 0)
-               goto err_exit;
-
-       if ((ret & 0xff) != BC_MAGIC) {
-               log_debug("%s: Invalid Magic, reset bootcounter.\n", __func__);
-               *val = 0;
-               return bootcount_i2c_set(dev, 0);
+       if (priv->size == 4) {
+               u32 bc;
+
+               ret = dm_i2c_read(priv->bcdev, priv->offset, (uint8_t *)&bc, sizeof(bc));
+               if (ret < 0)
+                       goto err_exit;
+
+               if ((bc & BOOTCOUNT_MAGIC_MASK) !=
+                   (CONFIG_SYS_BOOTCOUNT_MAGIC & BOOTCOUNT_MAGIC_MASK)) {
+                       log_debug("%s: Invalid Magic, reset bootcounter.\n", __func__);
+                       *val = 0;
+                       return bootcount_i2c_set(dev, 0);
+               }
+
+               *val = (bc & BOOTCOUNT_COUNT_MASK);
+       } else {
+               ret = dm_i2c_reg_read(priv->bcdev, priv->offset);
+               if (ret < 0)
+                       goto err_exit;
+
+               if ((ret & 0xff) != BC_MAGIC) {
+                       log_debug("%s: Invalid Magic, reset bootcounter.\n", __func__);
+                       *val = 0;
+                       return bootcount_i2c_set(dev, 0);
+               }
+
+               ret = dm_i2c_reg_read(priv->bcdev, priv->offset + 1);
+               if (ret < 0)
+                       goto err_exit;
+
+               *val = ret;
        }
 
-       ret = dm_i2c_reg_read(priv->bcdev, priv->offset + 1);
-       if (ret < 0)
-               goto err_exit;
-
-       *val = ret;
        return 0;
 
 err_exit:
@@ -73,6 +101,12 @@ static int bootcount_i2c_probe(struct udevice *dev)
        if (ret)
                goto exit;
 
+       priv->size = dev_read_u32_default(dev, "size", 2);
+       if (priv->size != 2 && priv->size != 4) {
+               ret = -EINVAL;
+               goto exit;
+       }
+
        ret = i2c_get_chip_by_phandle(dev, "i2cbcdev", &priv->bcdev);
 
 exit: