mtd: bcm47xxsflash: implement polling chip status

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c
index d1f0dec07a49f01230aea1d86f4086b4673e120c..2060856dbf977ad580923d06690f514c5db656c5 100644 (file)
--- a/drivers/mtd/devices/bcm47xxsflash.c
+++ b/drivers/mtd/devices/bcm47xxsflash.c
@@ -1,6 +1,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 #include <linux/mtd/mtd.h>
 #include <linux/platform_device.h>
 #include <linux/bcma/bcma.h>
@@ -12,6 +13,57 @@ MODULE_DESCRIPTION("Serial flash driver for BCMA bus");
 
 static const char * const probes[] = { "bcm47xxpart", NULL };
 
+/**************************************************
+ * Various helpers
+ **************************************************/
+
+static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)
+{
+       int i;
+
+       b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);
+       for (i = 0; i < 1000; i++) {
+               if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &
+                     BCMA_CC_FLASHCTL_BUSY))
+                       return;
+               cpu_relax();
+       }
+       pr_err("Control command failed (timeout)!\n");
+}
+
+static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)
+{
+       unsigned long deadline = jiffies + timeout;
+
+       do {
+               switch (b47s->type) {
+               case BCM47XXSFLASH_TYPE_ST:
+                       bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);
+                       if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+                             SR_ST_WIP))
+                               return 0;
+                       break;
+               case BCM47XXSFLASH_TYPE_ATMEL:
+                       bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);
+                       if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &
+                           SR_AT_READY)
+                               return 0;
+                       break;
+               }
+
+               cpu_relax();
+               udelay(1);
+       } while (!time_after_eq(jiffies, deadline));
+
+       pr_err("Timeout waiting for flash to be ready!\n");
+
+       return -EBUSY;
+}
+
+/**************************************************
+ * MTD ops
+ **************************************************/
+
 static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,
                              size_t *retlen, u_char *buf)
 {
@@ -97,6 +149,9 @@ static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
                goto err_dev_reg;
        }
 
+       if (bcm47xxsflash_poll(b47s, HZ / 10))
+               pr_warn("Serial flash busy\n");
+
        return 0;
 
 err_dev_reg: