[PATCH 3/3] omap nand : use onfi mode to compute optimized timings
Matthieu CASTET
matthieu.castet at parrot.com
Tue Nov 6 11:44:37 EST 2012
If the platform data give us nand timings (in gpmc_t), we use
them and not use onfi timings.
Tested on omap 3630 (with onfi flash and mode {2, 4 , 5})
Signed-off-by: Matthieu CASTET <matthieu.castet at parrot.com>
---
drivers/mtd/nand/omap2.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 134 insertions(+)
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index 618cf42..6c45c59 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -29,6 +29,7 @@
#include <plat/dma.h>
#include <plat/gpmc.h>
+#include <plat/cpu.h>
#include <linux/platform_data/mtd-nand-omap2.h>
#define DRIVER_NAME "omap2-nand"
@@ -153,6 +154,8 @@ struct omap_nand_info {
#endif
};
+static int optim_rd, optim_wr;
+
/**
* omap_prefetch_enable - configures and starts prefetch transfer
* @cs: cs (chip select) number
@@ -181,6 +184,13 @@ static int omap_prefetch_enable(int cs, int fifo_th, int dma_mode,
val = ((cs << PREFETCH_CONFIG1_CS_SHIFT) |
PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH |
(dma_mode << DMA_MPU_MODE_SHIFT) | (0x1 & is_write));
+ if (is_write) {
+ if (optim_wr)
+ val |= (1 << 27) /* ENABLEOPTIMIZEDACCESS */| (optim_wr << 28);
+ } else {
+ if (optim_rd)
+ val |= (1 << 27) /* ENABLEOPTIMIZEDACCESS */| (optim_rd << 28);
+ }
writel(val, info->reg.gpmc_prefetch_config1);
/* Start the prefetch engine */
@@ -1239,6 +1249,122 @@ static void omap3_free_bch(struct mtd_info *mtd)
}
#endif /* CONFIG_MTD_NAND_OMAP_BCH */
+/* Update hardware configuration after device geometry has been queried */
+static int omap_onfi_set(struct mtd_info* mtd, int mode)
+{
+ struct omap_nand_info *info = container_of(mtd,
+ struct omap_nand_info, mtd);
+
+ const struct reduced_onfi *tn = nand_get_timing(mode, 1);
+ int tmp;
+ struct gpmc_timings t;
+
+ pr_info("omap nand : setting onfi mode %d\n", mode);
+
+
+ /* only tested on 3630 */
+ if (!cpu_is_omap3630()) {
+ /* wr_access is shared with access */
+ return -EINVAL;
+ }
+
+ memset(&t, 0, sizeof(t));
+
+ /* all signal start at the same time :
+ we could delay nRE, nWE, but this won't
+ work with prefetcher optimisation...
+ */
+
+ t.cs_on = 0;
+ t.adv_on = 0;
+ t.oe_on = 0;
+ t.we_on = 0;
+
+ tmp = gpmc_round_ns_to_ticks(tn->twp);
+ /* nCS low to nWE high */
+ t.we_off = gpmc_round_ns_to_ticks(tn->twsetup) + tmp;
+
+ /* nCS low to end */
+ t.wr_cycle = t.we_off + max((int)tn->twh, tn->twc - tmp);
+
+ /* BCH need 4 cycles */
+ if (gpmc_ns_to_ticks(t.wr_cycle) < 4)
+ t.wr_cycle = gpmc_ticks_to_ns(4);
+ else if (gpmc_ns_to_ticks(t.wr_cycle) > 0x1f)
+ t.wr_cycle = gpmc_ticks_to_ns(0x1f);
+
+ t.cs_wr_off = t.wr_cycle;
+ t.adv_wr_off = t.wr_cycle;
+ t.wr_access = t.we_off;
+
+ tmp = gpmc_round_ns_to_ticks(tn->trp);
+ /* nCS low to nRE high */
+ t.oe_off = gpmc_round_ns_to_ticks(tn->trsetup) + tmp;
+
+ /* nCS low to end */
+ t.rd_cycle = t.oe_off + max((int)tn->treh, tn->trc - tmp);;
+
+ /* BCH need 4 cycles */
+ if (gpmc_ns_to_ticks(t.rd_cycle) < 4)
+ t.rd_cycle = gpmc_ticks_to_ns(4);
+ else if (gpmc_ns_to_ticks(t.rd_cycle) > 0x1f)
+ t.rd_cycle = gpmc_ticks_to_ns(0x1f);
+
+ t.cs_rd_off = t.rd_cycle;
+ t.adv_rd_off = t.rd_cycle; /* not used */
+ if (tn->edo)
+ t.access = t.rd_cycle;
+ else
+ t.access = t.oe_off;
+
+ t.page_burst_access = 0; /* not used */
+ t.wr_data_mux_bus = 0; /* not used not in MUXADDDATA mode */
+
+ /* we often overflow here ... */
+ tmp = gpmc_ns_to_ticks(tn->bta);
+ if (tmp > 0xf)
+ tmp = 0xf;
+ t.busturnaround = gpmc_ticks_to_ns(tmp);
+
+ tmp = gpmc_ns_to_ticks(tn->twhr);
+ if (tmp > 0xf)
+ tmp = 0xf;
+ t.cycle2cycledelay = gpmc_ticks_to_ns(tmp);
+
+ /*
+ XXX tbusy is not configurable
+ trm is not clear how much the gpmc wait between WAIT high and read.
+ But the linux driver doesn't use SYNCHROMODE in GPMC_PREFETCH_CONFIG1,
+ so we should be safe
+ */
+ pr_debug("nand timings\n");
+ pr_debug("oe_off=%d, rd_cycle=%d\n", t.oe_off, t.rd_cycle);
+ pr_debug("we_off=%d, wr_cycle=%d\n", t.we_off, t.wr_cycle);
+
+ /* make sure timming register got sane default */
+ gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG2, 0);
+ gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG3, 0);
+ gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG4, 0);
+ gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG5, 0);
+ gpmc_cs_write_reg(info->gpmc_cs, GPMC_CS_CONFIG6, (1<<31) | (1<<7));
+ gpmc_cs_set_timings(info->gpmc_cs, &t);
+
+ /* for burst we can remove twsetup/trsetup, but we should
+ make sure cycle is not less than 4 (for bch)
+
+ This number is the cycles to be
+ subtracted from RdCycleTime, WrCycleTime,
+ AccessTime, CSRdOffTime, CSWrOffTime,
+ ADVRdOffTime, ADVWrOffTime, OEOffTime, WEOffTime
+ */
+ optim_wr = min(gpmc_ns_to_ticks(t.wr_cycle) - 4,
+ gpmc_ns_to_ticks(tn->twsetup));
+ optim_rd = min(gpmc_ns_to_ticks(t.rd_cycle) - 4,
+ gpmc_ns_to_ticks(tn->trsetup));
+
+ return 0;
+}
+
static int __devinit omap_nand_probe(struct platform_device *pdev)
{
struct omap_nand_info *info;
@@ -1408,6 +1534,11 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
goto out_release_mem_region;
}
+ if (!pdata->gpmc_t) {
+ /* default to mode 0 for init */
+ omap_onfi_set(&info->mtd, 0);
+ }
+
/* update for 16 bits device */
if (info->nand.options & NAND_BUSWIDTH_16) {
if (!(pdata->bussize & NAND_OMAP_BUS_16)) {
@@ -1471,6 +1602,9 @@ static int __devinit omap_nand_probe(struct platform_device *pdev)
}
}
+ if (!pdata->gpmc_t && info->nand.onfi_speed >= 0)
+ omap_onfi_set(&info->mtd, info->nand.onfi_speed);
+
/* second phase scan */
if (nand_scan_tail(&info->mtd)) {
err = -ENXIO;
--
1.7.10.4
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