drivers: mtd: m25p80: convert "bool" read check into an enum

This is a cleanup prior to adding quad read support. This will facilitate
easy addition of more read commands check under an enum rather that defining a
separate bool for it.

Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 7eda71dbc183b7aa456e60a41f0490c882d94331..04f8a245ffefaaf2b2a6cf6e4dc8a04b90a4ce4b 100644 (file)
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -84,6 +84,11 @@
 
 /****************************************************************************/
 
+enum read_type {
+       M25P80_NORMAL = 0,
+       M25P80_FAST,
+};
+
 struct m25p {
        struct spi_device       *spi;
        struct mutex            lock;
@@ -94,7 +99,7 @@ struct m25p {
        u8                      read_opcode;
        u8                      program_opcode;
        u8                      *command;
-       bool                    fast_read;
+       enum read_type          flash_read;
 };
 
 static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
@@ -349,6 +354,24 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
        return 0;
 }
 
+/*
+ * Dummy Cycle calculation for different type of read.
+ * It can be used to support more commands with
+ * different dummy cycle requirements.
+ */
+static inline int m25p80_dummy_cycles_read(struct m25p *flash)
+{
+       switch (flash->flash_read) {
+       case M25P80_FAST:
+               return 1;
+       case M25P80_NORMAL:
+               return 0;
+       default:
+               dev_err(&flash->spi->dev, "No valid read type supported\n");
+               return -1;
+       }
+}
+
 /*
  * Read an address range from the flash chip.  The address range
  * may be any size provided it is within the physical boundaries.
@@ -360,6 +383,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
        struct spi_transfer t[2];
        struct spi_message m;
        uint8_t opcode;
+       int dummy;
 
        pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
                        __func__, (u32)from, len);
@@ -367,8 +391,14 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
        spi_message_init(&m);
        memset(t, 0, (sizeof t));
 
+       dummy =  m25p80_dummy_cycles_read(flash);
+       if (dummy < 0) {
+               dev_err(&flash->spi->dev, "No valid read command supported\n");
+               return -EINVAL;
+       }
+
        t[0].tx_buf = flash->command;
-       t[0].len = m25p_cmdsz(flash) + (flash->fast_read ? 1 : 0);
+       t[0].len = m25p_cmdsz(flash) + dummy;
        spi_message_add_tail(&t[0], &m);
 
        t[1].rx_buf = buf;
@@ -391,8 +421,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 
        spi_sync(flash->spi, &m);
 
-       *retlen = m.actual_length - m25p_cmdsz(flash) -
-                       (flash->fast_read ? 1 : 0);
+       *retlen = m.actual_length - m25p_cmdsz(flash) - dummy;
 
        mutex_unlock(&flash->lock);
 
@@ -1051,22 +1080,31 @@ static int m25p_probe(struct spi_device *spi)
        flash->page_size = info->page_size;
        flash->mtd.writebufsize = flash->page_size;
 
-       if (np)
+       if (np) {
                /* If we were instantiated by DT, use it */
-               flash->fast_read = of_property_read_bool(np, "m25p,fast-read");
-       else
+               if (of_property_read_bool(np, "m25p,fast-read"))
+                       flash->flash_read = M25P80_FAST;
+       } else {
                /* If we weren't instantiated by DT, default to fast-read */
-               flash->fast_read = true;
+               flash->flash_read = M25P80_FAST;
+       }
 
        /* Some devices cannot do fast-read, no matter what DT tells us */
        if (info->flags & M25P_NO_FR)
-               flash->fast_read = false;
+               flash->flash_read = M25P80_NORMAL;
 
        /* Default commands */
-       if (flash->fast_read)
+       switch (flash->flash_read) {
+       case M25P80_FAST:
                flash->read_opcode = OPCODE_FAST_READ;
-       else
+               break;
+       case M25P80_NORMAL:
                flash->read_opcode = OPCODE_NORM_READ;
+               break;
+       default:
+               dev_err(&flash->spi->dev, "No Read opcode defined\n");
+               return -EINVAL;
+       }
 
        flash->program_opcode = OPCODE_PP;
 
@@ -1077,9 +1115,14 @@ static int m25p_probe(struct spi_device *spi)
                flash->addr_width = 4;
                if (JEDEC_MFR(info->jedec_id) == CFI_MFR_AMD) {
                        /* Dedicated 4-byte command set */
-                       flash->read_opcode = flash->fast_read ?
-                               OPCODE_FAST_READ_4B :
-                               OPCODE_NORM_READ_4B;
+                       switch (flash->flash_read) {
+                       case M25P80_FAST:
+                               flash->read_opcode = OPCODE_FAST_READ_4B;
+                               break;
+                       case M25P80_NORMAL:
+                               flash->read_opcode = OPCODE_NORM_READ_4B;
+                               break;
+                       }
                        flash->program_opcode = OPCODE_PP_4B;
                        /* No small sector erase for 4-byte command set */
                        flash->erase_opcode = OPCODE_SE_4B;