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authorSekhar Nori2010-08-09 15:46:36 +0530
committerKevin Hilman2010-09-24 07:40:26 -0700
commita88dbc5bfdd26132bbf0ad19dd672e036971d74d (patch)
tree112aa4d073c606352a2fc938a953a913b21d18bc /drivers/mtd/nand/davinci_nand.c
parent8060ef4da9e73f461adf2ba1922ea5400a61cf98 (diff)
nand: davinci: add support for timing configuration
This patch modifies the DaVinci NAND driver to use the new AEMIF timing setup API to configure the NAND access timings. Earlier, AEMIF configuration was being done as a special case for DM644x board, but now more boards emerge which have capability to boot for other media (SPI flash, NOR flash) and have the kernel access NAND flash. This means that kernel cannot always depend on the bootloader to setup the NAND. Also, on platforms such as da850/omap-l138, the aemif input frequency changes as cpu frequency changes; necessiating re-calculation of timimg values as part of cpufreq transtitions. This patch forms the basis for adding that support. Signed-off-by: Sekhar Nori <nsekhar@ti.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'drivers/mtd/nand/davinci_nand.c')
-rw-r--r--drivers/mtd/nand/davinci_nand.c60
1 files changed, 22 insertions, 38 deletions
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c
index 8e2d56c36811..8beb0d0233b5 100644
--- a/drivers/mtd/nand/davinci_nand.c
+++ b/drivers/mtd/nand/davinci_nand.c
@@ -75,6 +75,8 @@ struct davinci_nand_info {
uint32_t mask_cle;
uint32_t core_chipsel;
+
+ struct davinci_aemif_timing *timing;
};
static DEFINE_SPINLOCK(davinci_nand_lock);
@@ -479,36 +481,6 @@ static int nand_davinci_dev_ready(struct mtd_info *mtd)
return davinci_nand_readl(info, NANDFSR_OFFSET) & BIT(0);
}
-static void __init nand_dm6446evm_flash_init(struct davinci_nand_info *info)
-{
- uint32_t regval, a1cr;
-
- /*
- * NAND FLASH timings @ PLL1 == 459 MHz
- * - AEMIF.CLK freq = PLL1/6 = 459/6 = 76.5 MHz
- * - AEMIF.CLK period = 1/76.5 MHz = 13.1 ns
- */
- regval = 0
- | (0 << 31) /* selectStrobe */
- | (0 << 30) /* extWait (never with NAND) */
- | (1 << 26) /* writeSetup 10 ns */
- | (3 << 20) /* writeStrobe 40 ns */
- | (1 << 17) /* writeHold 10 ns */
- | (0 << 13) /* readSetup 10 ns */
- | (3 << 7) /* readStrobe 60 ns */
- | (0 << 4) /* readHold 10 ns */
- | (3 << 2) /* turnAround ?? ns */
- | (0 << 0) /* asyncSize 8-bit bus */
- ;
- a1cr = davinci_nand_readl(info, A1CR_OFFSET);
- if (a1cr != regval) {
- dev_dbg(info->dev, "Warning: NAND config: Set A1CR " \
- "reg to 0x%08x, was 0x%08x, should be done by " \
- "bootloader.\n", regval, a1cr);
- davinci_nand_writel(info, A1CR_OFFSET, regval);
- }
-}
-
/*----------------------------------------------------------------------*/
/* An ECC layout for using 4-bit ECC with small-page flash, storing
@@ -612,6 +584,7 @@ static int __init nand_davinci_probe(struct platform_device *pdev)
info->chip.options = pdata->options;
info->chip.bbt_td = pdata->bbt_td;
info->chip.bbt_md = pdata->bbt_md;
+ info->timing = pdata->timing;
info->ioaddr = (uint32_t __force) vaddr;
@@ -689,15 +662,25 @@ static int __init nand_davinci_probe(struct platform_device *pdev)
goto err_clk_enable;
}
- /* EMIF timings should normally be set by the boot loader,
- * especially after boot-from-NAND. The *only* reason to
- * have this special casing for the DM6446 EVM is to work
- * with boot-from-NOR ... with CS0 manually re-jumpered
- * (after startup) so it addresses the NAND flash, not NOR.
- * Even for dev boards, that's unusually rude...
+ /*
+ * Setup Async configuration register in case we did not boot from
+ * NAND and so bootloader did not bother to set it up.
*/
- if (machine_is_davinci_evm())
- nand_dm6446evm_flash_init(info);
+ val = davinci_nand_readl(info, A1CR_OFFSET + info->core_chipsel * 4);
+
+ /* Extended Wait is not valid and Select Strobe mode is not used */
+ val &= ~(ACR_ASIZE_MASK | ACR_EW_MASK | ACR_SS_MASK);
+ if (info->chip.options & NAND_BUSWIDTH_16)
+ val |= 0x1;
+
+ davinci_nand_writel(info, A1CR_OFFSET + info->core_chipsel * 4, val);
+
+ ret = davinci_aemif_setup_timing(info->timing, info->base,
+ info->core_chipsel);
+ if (ret < 0) {
+ dev_dbg(&pdev->dev, "NAND timing values setup fail\n");
+ goto err_timing;
+ }
spin_lock_irq(&davinci_nand_lock);
@@ -810,6 +793,7 @@ syndrome_done:
return 0;
err_scan:
+err_timing:
clk_disable(info->clk);
err_clk_enable: