[PATCH 05/19] drivers: mtd: nand: cadence: Add support for read status command

[dinesh . maniyam]

From: Dinesh Maniyam <dinesh.mani...@intel.com>

This patch will add support for read status command
in Cadence NAND driver. This status bit is important to check
whether the flash is write-protected.

Signed-off-by: Dinesh Maniyam <dinesh.mani...@intel.com>
---
 drivers/mtd/nand/raw/cadence_nand.c | 46 ++++++++++++++++++++++++++++-
 include/cadence-nand.h              |  2 ++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/cadence_nand.c 
b/drivers/mtd/nand/raw/cadence_nand.c
index f9f28c392b..670f5ca184 100644
--- a/drivers/mtd/nand/raw/cadence_nand.c
+++ b/drivers/mtd/nand/raw/cadence_nand.c
@@ -343,6 +343,7 @@ static int cadence_nand_generic_cmd_send(struct 
cadence_nand_info *cadence,
 
        /* Issue command. */
        writel_relaxed(reg, cadence->reg + CMD_REG0);
+       cadence->buf_index = 0;
 
        return 0;
 }
@@ -1902,9 +1903,42 @@ static void cadence_nand_select_chip(struct mtd_info 
*mtd, int chipnr)
        }
 }
 
+static int cadence_nand_status(struct mtd_info *mtd, unsigned int command)
+{
+       struct cadence_nand_info *cadence = mtd_to_cadence(mtd);
+       int ret = 0;
+
+       ret = cadence_nand_cmd_opcode(cadence, command);
+       if (ret)
+               return ret;
+
+       ret = cadence_nand_cmd_data(cadence, 1, GCMD_DIR_READ);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
 static void cadence_nand_cmdfunc(struct mtd_info *mtd, unsigned int command,
                                 int offset_in_page, int page)
 {
+       struct cadence_nand_info *cadence = mtd_to_cadence(mtd);
+       int ret = 0;
+
+       cadence->cmd = command;
+       switch (command) {
+       case NAND_CMD_STATUS:
+               ret = cadence_nand_status(mtd, command);
+               break;
+       /*
+        * ecc will override other command for read, write and erase
+        */
+       default:
+               break;
+       }
+
+       if (ret != 0)
+               printf("ERROR:%s:command:0x%x\n", __func__, cadence->cmd);
 }
 
 static int cadence_nand_dev_ready(struct mtd_info *mtd)
@@ -1921,7 +1955,17 @@ static int cadence_nand_dev_ready(struct mtd_info *mtd)
 
 static u8 cadence_nand_read_byte(struct mtd_info *mtd)
 {
-       return 0;
+       struct cadence_nand_info *cadence = mtd_to_cadence(mtd);
+       u32 size = 1;
+       u8 val;
+
+       if (cadence->buf_index == 0)
+               cadence_nand_read_buf(mtd, &cadence->buf[0], size);
+
+       val = *(&cadence->buf[0] + cadence->buf_index);
+       cadence->buf_index++;
+
+       return val;
 }
 
 static void cadence_nand_write_byte(struct mtd_info *mtd, u8 byte)
diff --git a/include/cadence-nand.h b/include/cadence-nand.h
index 101f60ce0e..5b9d6e0382 100644
--- a/include/cadence-nand.h
+++ b/include/cadence-nand.h
@@ -453,6 +453,8 @@ struct cadence_nand_info {
        u8 *buf;
        u32 buf_size;
        u8 *stat;
+       u8 cmd;
+       u32 buf_index;
 
        u8 curr_corr_str_idx;
 
-- 
2.26.2