mtd: nand: denali: remove unneeded find_valid_banks()

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Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=959e9f2ae9dac4821d7da354a37272650febebbe
Commit:     959e9f2ae9dac4821d7da354a37272650febebbe
Parent:     b21ff825d6b7fa7122f9c4455f9a0f157b9fb225
Author:     Masahiro Yamada <yamada.masahiro at socionext.com>
AuthorDate: Tue Jun 13 22:45:36 2017 +0900
Committer:  Boris Brezillon <boris.brezillon at free-electrons.com>
CommitDate: Tue Jun 20 09:14:25 2017 +0200

    mtd: nand: denali: remove unneeded find_valid_banks()
    
    The function find_valid_banks() issues the Read ID (0x90) command,
    then compares the first byte (Manufacturer ID) of each bank with
    the one of bank0.
    
    This is equivalent to what nand_scan_ident() does.  The number of
    chips is detected there, so this is unneeded.
    
    What is worse for find_valid_banks() is that, if multiple chips are
    connected to INTEL_CE4100 platform, it crashes the kernel by BUG().
    This is what we should avoid.  This function is just harmful and
    unneeded.
    
    Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
    Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
 drivers/mtd/nand/denali.c | 47 -----------------------------------------------
 drivers/mtd/nand/denali.h |  1 -
 2 files changed, 48 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 7133a33..122df4c 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -338,51 +338,6 @@ static void get_samsung_nand_para(struct denali_nand_info *denali,
 }
 
 /*
- * determines how many NAND chips are connected to the controller. Note for
- * Intel CE4100 devices we don't support more than one device.
- */
-static void find_valid_banks(struct denali_nand_info *denali)
-{
-	uint32_t id[denali->max_banks];
-	int i;
-
-	denali->total_used_banks = 1;
-	for (i = 0; i < denali->max_banks; i++) {
-		index_addr(denali, MODE_11 | (i << 24) | 0, 0x90);
-		index_addr(denali, MODE_11 | (i << 24) | 1, 0);
-		index_addr_read_data(denali, MODE_11 | (i << 24) | 2, &id[i]);
-
-		dev_dbg(denali->dev,
-			"Return 1st ID for bank[%d]: %x\n", i, id[i]);
-
-		if (i == 0) {
-			if (!(id[i] & 0x0ff))
-				break; /* WTF? */
-		} else {
-			if ((id[i] & 0x0ff) == (id[0] & 0x0ff))
-				denali->total_used_banks++;
-			else
-				break;
-		}
-	}
-
-	if (denali->platform == INTEL_CE4100) {
-		/*
-		 * Platform limitations of the CE4100 device limit
-		 * users to a single chip solution for NAND.
-		 * Multichip support is not enabled.
-		 */
-		if (denali->total_used_banks != 1) {
-			dev_err(denali->dev,
-				"Sorry, Intel CE4100 only supports a single NAND device.\n");
-			BUG();
-		}
-	}
-	dev_dbg(denali->dev,
-		"denali->total_used_banks: %d\n", denali->total_used_banks);
-}
-
-/*
  * Use the configuration feature register to determine the maximum number of
  * banks that the hardware supports.
  */
@@ -439,8 +394,6 @@ static uint16_t denali_nand_timing_set(struct denali_nand_info *denali)
 			ioread32(denali->flash_reg + RDWR_EN_HI_CNT),
 			ioread32(denali->flash_reg + CS_SETUP_CNT));
 
-	find_valid_banks(denali);
-
 	/*
 	 * If the user specified to override the default timings
 	 * with a specific ONFI mode, we apply those changes here.
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index 352d832..0e4a896 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -326,7 +326,6 @@ struct denali_nand_info {
 	int platform;
 	struct nand_buf buf;
 	struct device *dev;
-	int total_used_banks;
 	int page;
 	void __iomem *flash_reg;	/* Register Interface */
 	void __iomem *flash_mem;	/* Host Data/Command Interface */