mtd: m25p80: Add support for CAT25xxx serial EEPROMs

CAT25 chips (as manufactured by On Semiconductor, previously Catalyst
Semiconductor) are similar to the original M25Px0 chips, except:

- Address width can vary (1-2 bytes, in contrast to 3 bytes in M25P
  chips). So, implement convenient m25p_addr2cmd() and m25p_cmdsz()
  calls, and place address width information into flash_info struct;

- Page size can vary, therefore we shouldn't hardcode it, so get rid
  of FLASH_PAGESIZE definition, and place the page size information
  into flash_info struct;

- CAT25 EEPROMs don't need to be erased, so add NO_ERASE flag, and
  propagate it to the mtd subsystem.

[dwmw2: Fix up for conflicts with DMA safety patch]
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 69 insertions, 45 deletions

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index e6892851e813..8f8c249d7c46 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -29,9 +29,6 @@
 #include <linux/spi/spi.h>
 #include <linux/spi/flash.h>
 
-
-#define FLASH_PAGESIZE          256
-
 /* Flash opcodes. */
 #define OPCODE_WREN             0x06    /* Write enable */
 #define OPCODE_RDSR             0x05    /* Read status register */
@@ -61,7 +58,7 @@
 
 /* Define max times to check status register before we give up. */
 #define MAX_READY_WAIT_JIFFIES  (40 * HZ)       /* M25P16 specs 40s max chip erase */
-#define CMD_SIZE                4
+#define MAX_CMD_SIZE            4
 
 #ifdef CONFIG_M25PXX_USE_FAST_READ
 #define OPCODE_READ     OPCODE_FAST_READ
@@ -78,6 +75,8 @@ struct m25p {
         struct mutex            lock;
         struct mtd_info         mtd;
         unsigned                partitioned:1;
+        u16                     page_size;
+        u16                     addr_width;
         u8                      erase_opcode;
         u8                      *command;
 };
@@ -198,6 +197,19 @@ static int erase_chip(struct m25p *flash)
         return 0;
 }
 
+static void m25p_addr2cmd(struct m25p *flash, unsigned int addr, u8 *cmd)
+{
+        /* opcode is in cmd[0] */
+        cmd[1] = addr >> (flash->addr_width * 8 -  8);
+        cmd[2] = addr >> (flash->addr_width * 8 - 16);
+        cmd[3] = addr >> (flash->addr_width * 8 - 24);
+}
+
+static int m25p_cmdsz(struct m25p *flash)
+{
+        return 1 + flash->addr_width;
+}
+
 /*
  * Erase one sector of flash memory at offset ``offset'' which is any
  * address within the sector which should be erased.
@@ -219,11 +231,9 @@ static int erase_sector(struct m25p *flash, u32 offset)
 
         /* Set up command buffer. */
         flash->command[0] = flash->erase_opcode;
-        flash->command[1] = offset >> 16;
-        flash->command[2] = offset >> 8;
-        flash->command[3] = offset;
+        m25p_addr2cmd(flash, offset, flash->command);
 
-        spi_write(flash->spi, flash->command, CMD_SIZE);
+        spi_write(flash->spi, flash->command, m25p_cmdsz(flash));
 
         return 0;
 }
@@ -325,7 +335,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
          * Should add 1 byte DUMMY_BYTE.
          */
         t[0].tx_buf = flash->command;
-        t[0].len = CMD_SIZE + FAST_READ_DUMMY_BYTE;
+        t[0].len = m25p_cmdsz(flash) + FAST_READ_DUMMY_BYTE;
         spi_message_add_tail(&t[0], &m);
 
         t[1].rx_buf = buf;
@@ -352,13 +362,11 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 
         /* Set up the write data buffer. */
         flash->command[0] = OPCODE_READ;
-        flash->command[1] = from >> 16;
-        flash->command[2] = from >> 8;
-        flash->command[3] = from;
+        m25p_addr2cmd(flash, from, flash->command);
 
         spi_sync(flash->spi, &m);
 
-        *retlen = m.actual_length - CMD_SIZE - FAST_READ_DUMMY_BYTE;
+        *retlen = m.actual_length - m25p_cmdsz(flash) - FAST_READ_DUMMY_BYTE;
 
         mutex_unlock(&flash->lock);
 
@@ -396,7 +404,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
         memset(t, 0, (sizeof t));
 
         t[0].tx_buf = flash->command;
-        t[0].len = CMD_SIZE;
+        t[0].len = m25p_cmdsz(flash);
         spi_message_add_tail(&t[0], &m);
 
         t[1].tx_buf = buf;
@@ -414,41 +422,36 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
 
         /* Set up the opcode in the write buffer. */
         flash->command[0] = OPCODE_PP;
-        flash->command[1] = to >> 16;
-        flash->command[2] = to >> 8;
-        flash->command[3] = to;
+        m25p_addr2cmd(flash, to, flash->command);
 
-        /* what page do we start with? */
-        page_offset = to % FLASH_PAGESIZE;
+        page_offset = to & (flash->page_size - 1);
 
         /* do all the bytes fit onto one page? */
-        if (page_offset + len <= FLASH_PAGESIZE) {
+        if (page_offset + len <= flash->page_size) {
                 t[1].len = len;
 
                 spi_sync(flash->spi, &m);
 
-                *retlen = m.actual_length - CMD_SIZE;
+                *retlen = m.actual_length - m25p_cmdsz(flash);
         } else {
                 u32 i;
 
                 /* the size of data remaining on the first page */
-                page_size = FLASH_PAGESIZE - page_offset;
+                page_size = flash->page_size - page_offset;
 
                 t[1].len = page_size;
                 spi_sync(flash->spi, &m);
 
-                *retlen = m.actual_length - CMD_SIZE;
+                *retlen = m.actual_length - m25p_cmdsz(flash);
 
-                /* write everything in PAGESIZE chunks */
+                /* write everything in flash->page_size chunks */
                 for (i = page_size; i < len; i += page_size) {
                         page_size = len - i;
-                        if (page_size > FLASH_PAGESIZE)
-                                page_size = FLASH_PAGESIZE;
+                        if (page_size > flash->page_size)
+                                page_size = flash->page_size;
 
                         /* write the next page to flash */
-                        flash->command[1] = (to + i) >> 16;
-                        flash->command[2] = (to + i) >> 8;
-                        flash->command[3] = (to + i);
+                        m25p_addr2cmd(flash, to + i, flash->command);
 
                         t[1].tx_buf = buf + i;
                         t[1].len = page_size;
@@ -460,7 +463,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
                         spi_sync(flash->spi, &m);
 
                         if (retlen)
-                                *retlen += m.actual_length - CMD_SIZE;
+                                *retlen += m.actual_length - m25p_cmdsz(flash);
                 }
         }
 
@@ -492,7 +495,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
         memset(t, 0, (sizeof t));
 
         t[0].tx_buf = flash->command;
-        t[0].len = CMD_SIZE;
+        t[0].len = m25p_cmdsz(flash);
         spi_message_add_tail(&t[0], &m);
 
         t[1].tx_buf = buf;
@@ -511,9 +514,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
         /* Start write from odd address. */
         if (actual) {
                 flash->command[0] = OPCODE_BP;
-                flash->command[1] = to >> 16;
-                flash->command[2] = to >> 8;
-                flash->command[3] = to;
+                m25p_addr2cmd(flash, to, flash->command);
 
                 /* write one byte. */
                 t[1].len = 1;
@@ -521,17 +522,15 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
                 ret = wait_till_ready(flash);
                 if (ret)
                         goto time_out;
-                *retlen += m.actual_length - CMD_SIZE;
+                *retlen += m.actual_length - m25p_cmdsz(flash);
         }
         to += actual;
 
         flash->command[0] = OPCODE_AAI_WP;
-        flash->command[1] = to >> 16;
-        flash->command[2] = to >> 8;
-        flash->command[3] = to;
+        m25p_addr2cmd(flash, to, flash->command);
 
         /* Write out most of the data here. */
-        cmd_sz = CMD_SIZE;
+        cmd_sz = m25p_cmdsz(flash);
         for (; actual < len - 1; actual += 2) {
                 t[0].len = cmd_sz;
                 /* write two bytes. */
@@ -555,10 +554,8 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
         if (actual != len) {
                 write_enable(flash);
                 flash->command[0] = OPCODE_BP;
-                flash->command[1] = to >> 16;
-                flash->command[2] = to >> 8;
-                flash->command[3] = to;
-                t[0].len = CMD_SIZE;
+                m25p_addr2cmd(flash, to, flash->command);
+                t[0].len = m25p_cmdsz(flash);
                 t[1].len = 1;
                 t[1].tx_buf = buf + actual;
 
@@ -566,7 +563,7 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
                 ret = wait_till_ready(flash);
                 if (ret)
                         goto time_out;
-                *retlen += m.actual_length - CMD_SIZE;
+                *retlen += m.actual_length - m25p_cmdsz(flash);
                 write_disable(flash);
         }
 
@@ -595,8 +592,12 @@ struct flash_info {
         unsigned        sector_size;
         u16             n_sectors;
 
+        u16             page_size;
+        u16             addr_width;
+
         u16             flags;
 #define SECT_4K         0x01            /* OPCODE_BE_4K works uniformly */
+#define M25P_NO_ERASE   0x02            /* No erase command needed */
 };
 
 #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)      \
@@ -605,9 +606,20 @@ struct flash_info {
                 .ext_id = (_ext_id),                                    \
                 .sector_size = (_sector_size),                          \
                 .n_sectors = (_n_sectors),                              \
+                .page_size = 256,                                       \
+                .addr_width = 3,                                        \
                 .flags = (_flags),                                      \
         })
 
+#define CAT25_INFO(_sector_size, _n_sectors, _page_size, _addr_width)   \
+        ((kernel_ulong_t)&(struct flash_info) {                         \
+                .sector_size = (_sector_size),                          \
+                .n_sectors = (_n_sectors),                              \
+                .page_size = (_page_size),                              \
+                .addr_width = (_addr_width),                            \
+                .flags = M25P_NO_ERASE,                                 \
+        })
+
 /* NOTE: double check command sets and memory organization when you add
  * more flash chips.  This current list focusses on newer chips, which
  * have been converging on command sets which including JEDEC ID.
@@ -680,6 +692,13 @@ static const struct spi_device_id m25p_ids[] = {
         { "w25x16", INFO(0xef3015, 0, 64 * 1024,  32, SECT_4K) },
         { "w25x32", INFO(0xef3016, 0, 64 * 1024,  64, SECT_4K) },
         { "w25x64", INFO(0xef3017, 0, 64 * 1024, 128, SECT_4K) },
+
+        /* Catalyst / On Semiconductor -- non-JEDEC */
+        { "cat25c11", CAT25_INFO(  16, 8, 16, 1) },
+        { "cat25c03", CAT25_INFO(  32, 8, 16, 2) },
+        { "cat25c09", CAT25_INFO( 128, 8, 32, 2) },
+        { "cat25c17", CAT25_INFO( 256, 8, 32, 2) },
+        { "cat25128", CAT25_INFO(2048, 8, 64, 2) },
         { },
 };
 MODULE_DEVICE_TABLE(spi, m25p_ids);
@@ -793,7 +812,7 @@ static int __devinit m25p_probe(struct spi_device *spi)
         flash = kzalloc(sizeof *flash, GFP_KERNEL);
         if (!flash)
                 return -ENOMEM;
-        flash->command = kmalloc(CMD_SIZE + FAST_READ_DUMMY_BYTE, GFP_KERNEL);
+        flash->command = kmalloc(MAX_CMD_SIZE + FAST_READ_DUMMY_BYTE, GFP_KERNEL);
         if (!flash->command) {
                 kfree(flash);
                 return -ENOMEM;
@@ -841,7 +860,12 @@ static int __devinit m25p_probe(struct spi_device *spi)
                 flash->mtd.erasesize = info->sector_size;
         }
 
+        if (info->flags & M25P_NO_ERASE)
+                flash->mtd.flags |= MTD_NO_ERASE;
+
         flash->mtd.dev.parent = &spi->dev;
+        flash->page_size = info->page_size;
+        flash->addr_width = info->addr_width;
 
         dev_info(&spi->dev, "%s (%lld Kbytes)\n", id->name,
                         (long long)flash->mtd.size >> 10);