sf: atmel: implement power-of-two write/erase funcs

Signed-off-by: Todor I Mollov <tmollov@ucsd.edu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>

diff --git a/drivers/mtd/spi/atmel.c b/drivers/mtd/spi/atmel.c
index c3b936f16a0d27019adcf96c6b657a98e91ec5b7..3bc2dff8b21a9d35fc28f3a8d466ffbb5f938097 100644 (file)
--- a/drivers/mtd/spi/atmel.c
+++ b/drivers/mtd/spi/atmel.c
@@ -196,6 +196,75 @@ static int dataflash_read_fast_at45(struct spi_flash *flash,
        return spi_flash_read_common(flash, cmd, sizeof(cmd), buf, len);
 }
 
+/*
+ * TODO: the two write funcs (_p2/_at45) should get unified ...
+ */
+static int dataflash_write_p2(struct spi_flash *flash,
+               u32 offset, size_t len, const void *buf)
+{
+       struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
+       unsigned long page_size;
+       u32 addr = offset;
+       size_t chunk_len;
+       size_t actual;
+       int ret;
+       u8 cmd[4];
+
+       /*
+        * TODO: This function currently uses only page buffer #1.  We can
+        * speed this up by using both buffers and loading one buffer while
+        * the other is being programmed into main memory.
+        */
+
+       page_size = (1 << asf->params->l2_page_size);
+
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       for (actual = 0; actual < len; actual += chunk_len) {
+               chunk_len = min(len - actual, page_size - (addr % page_size));
+
+               /* Use the same address bits for both commands */
+               cmd[0] = CMD_AT45_LOAD_BUF1;
+               cmd[1] = addr >> 16;
+               cmd[2] = addr >> 8;
+               cmd[3] = addr;
+
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4,
+                               buf + actual, chunk_len);
+               if (ret < 0) {
+                       debug("SF: Loading AT45 buffer failed\n");
+                       goto out;
+               }
+
+               cmd[0] = CMD_AT45_PROG_BUF1;
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
+               if (ret < 0) {
+                       debug("SF: AT45 page programming failed\n");
+                       goto out;
+               }
+
+               ret = at45_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
+               if (ret < 0) {
+                       debug("SF: AT45 page programming timed out\n");
+                       goto out;
+               }
+
+               addr += chunk_len;
+       }
+
+       debug("SF: AT45: Successfully programmed %zu bytes @ 0x%x\n",
+                       len, offset);
+       ret = 0;
+
+out:
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
 static int dataflash_write_at45(struct spi_flash *flash,
                u32 offset, size_t len, const void *buf)
 {
@@ -209,6 +278,12 @@ static int dataflash_write_at45(struct spi_flash *flash,
        int ret;
        u8 cmd[4];
 
+       /*
+        * TODO: This function currently uses only page buffer #1.  We can
+        * speed this up by using both buffers and loading one buffer while
+        * the other is being programmed into main memory.
+        */
+
        page_shift = asf->params->l2_page_size;
        page_size = (1 << page_shift) + (1 << (page_shift - 5));
        page_shift++;
@@ -263,6 +338,68 @@ out:
        return ret;
 }
 
+/*
+ * TODO: the two erase funcs (_p2/_at45) should get unified ...
+ */
+int dataflash_erase_p2(struct spi_flash *flash, u32 offset, size_t len)
+{
+       struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
+       unsigned long page_size;
+
+       size_t actual;
+       int ret;
+       u8 cmd[4];
+
+       /*
+        * TODO: This function currently uses page erase only. We can
+        * probably speed things up by using block and/or sector erase
+        * when possible.
+        */
+
+       page_size = (1 << asf->params->l2_page_size);
+
+       if (offset % page_size || len % page_size) {
+               debug("SF: Erase offset/length not multiple of page size\n");
+               return -1;
+       }
+
+       cmd[0] = CMD_AT45_ERASE_PAGE;
+       cmd[3] = 0x00;
+
+       ret = spi_claim_bus(flash->spi);
+       if (ret) {
+               debug("SF: Unable to claim SPI bus\n");
+               return ret;
+       }
+
+       for (actual = 0; actual < len; actual += page_size) {
+               cmd[1] = offset >> 16;
+               cmd[2] = offset >> 8;
+
+               ret = spi_flash_cmd_write(flash->spi, cmd, 4, NULL, 0);
+               if (ret < 0) {
+                       debug("SF: AT45 page erase failed\n");
+                       goto out;
+               }
+
+               ret = at45_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
+               if (ret < 0) {
+                       debug("SF: AT45 page erase timed out\n");
+                       goto out;
+               }
+
+               offset += page_size;
+       }
+
+       debug("SF: AT45: Successfully erased %zu bytes @ 0x%x\n",
+                       len, offset);
+       ret = 0;
+
+out:
+       spi_release_bus(flash->spi);
+       return ret;
+}
+
 int dataflash_erase_at45(struct spi_flash *flash, u32 offset, size_t len)
 {
        struct atmel_spi_flash *asf = to_atmel_spi_flash(flash);
@@ -382,6 +519,8 @@ struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode)
                        page_size += 1 << (params->l2_page_size - 5);
                } else {
                        asf->flash.read = dataflash_read_fast_p2;
+                       asf->flash.write = dataflash_write_p2;
+                       asf->flash.erase = dataflash_erase_p2;
                }
 
                break;