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>

1 files changed, 57 insertions, 14 deletions

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 7eda71dbc183..04f8a245ffef 100644
--- 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)
@@ -350,6 +355,24 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
 }
 
 /*
+ * 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;