[PATCH v2 4/5] nvmem: sunxi-sid: add new reg_read func

[Yangtao Li]

Because there was an endianness issue. It seems that reg_read
function which the nvmem the driver currently exposes is wrong.
So add the new read function, the new function is used when the
native_endian flag is set.

Signed-off-by: Yangtao Li <tiny.win...@gmail.com>
---
 drivers/nvmem/sunxi_sid.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
index 54620d72ddb9..5b8a42f686cd 100644
--- a/drivers/nvmem/sunxi_sid.c
+++ b/drivers/nvmem/sunxi_sid.c
@@ -37,6 +37,7 @@ struct sunxi_sid_cfg {
        u32     value_offset;
        u32     size;
        bool    need_register_readout;
+       bool    native_endian;
 };
 
 struct sunxi_sid {
@@ -75,6 +76,31 @@ static int sunxi_sid_read(void *context, unsigned int offset,
        return 0;
 }
 
+static u8 sunxi_sid_read_byte_native(const struct sunxi_sid *sid,
+                             const unsigned int offset)
+{
+       u32 sid_key;
+
+       sid_key = ioread32(sid->base + round_down(offset, 4));
+       sid_key >>= (offset % 4) * 8;
+
+       return sid_key;
+}
+
+static int sunxi_sid_read_native(void *context, unsigned int offset,
+                         void *val, size_t bytes)
+{
+       struct sunxi_sid *sid = context;
+       u8 *buf = val;
+
+       offset += sid->value_offset;
+
+       while (bytes--)
+               *buf++ = sunxi_sid_read_byte_native(sid, offset++);
+
+       return 0;
+}
+
 static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
                                      const unsigned int offset,
                                      u32 *out)
@@ -169,9 +195,12 @@ static int sunxi_sid_probe(struct platform_device *pdev)
        econfig.dev = dev;
        if (cfg->need_register_readout)
                econfig.reg_read = sun8i_sid_read_by_reg;
+       else if (cfg->native_endian)
+               econfig.reg_read = sunxi_sid_read_native;
        else
                econfig.reg_read = sunxi_sid_read;
        econfig.priv = sid;
+
        nvmem = devm_nvmem_register(dev, &econfig);
        if (IS_ERR(nvmem))
                return PTR_ERR(nvmem);
-- 
2.17.0