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Subject[PATCH v5 04/12] mtd: pxa3xx_nand: add helpers to setup the timings
Date
Add helpers to setup the timings in the pxa3xx driver. These helpers
allow to either make use of the nand framework nand_sdr_timings or the
pxa3xx specific pxa3xx_nand_host, for compatibility reasons.

Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
---
drivers/mtd/nand/pxa3xx_nand.c | 91 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 91 insertions(+)

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 3eb42093db27..b5aad4c46115 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -384,6 +384,97 @@ static void pxa3xx_nand_set_timing(struct pxa3xx_nand_host *host,
nand_writel(info, NDTR1CS0, ndtr1);
}

+static void pxa3xx_nand_set_sdr_timing(struct pxa3xx_nand_host *host,
+ const struct nand_sdr_timings *t)
+{
+ struct pxa3xx_nand_info *info = host->info_data;
+ struct nand_chip *chip = &host->chip;
+ unsigned long nand_clk = clk_get_rate(info->clk);
+ uint32_t ndtr0, ndtr1;
+
+ u32 tCH_min = DIV_ROUND_UP(t->tCH_min, 1000);
+ u32 tCS_min = DIV_ROUND_UP(t->tCS_min, 1000);
+ u32 tWH_min = DIV_ROUND_UP(t->tWH_min, 1000);
+ u32 tWP_min = DIV_ROUND_UP(t->tWC_min - tWH_min, 1000);
+ u32 tREH_min = DIV_ROUND_UP(t->tREH_min, 1000);
+ u32 tRP_min = DIV_ROUND_UP(t->tRC_min - tREH_min, 1000);
+ u32 tR = chip->chip_delay * 1000;
+ u32 tWHR_min = DIV_ROUND_UP(t->tWHR_min, 1000);
+ u32 tAR_min = DIV_ROUND_UP(t->tAR_min, 1000);
+
+ /* fallback to a default value if tR = 0 */
+ if (!tR)
+ tR = 20000;
+
+ ndtr0 = NDTR0_tCH(ns2cycle(tCH_min, nand_clk)) |
+ NDTR0_tCS(ns2cycle(tCS_min, nand_clk)) |
+ NDTR0_tWH(ns2cycle(tWH_min, nand_clk)) |
+ NDTR0_tWP(ns2cycle(tWP_min, nand_clk)) |
+ NDTR0_tRH(ns2cycle(tREH_min, nand_clk)) |
+ NDTR0_tRP(ns2cycle(tRP_min, nand_clk));
+
+ ndtr1 = NDTR1_tR(ns2cycle(tR, nand_clk)) |
+ NDTR1_tWHR(ns2cycle(tWHR_min, nand_clk)) |
+ NDTR1_tAR(ns2cycle(tAR_min, nand_clk));
+
+ info->ndtr0cs0 = ndtr0;
+ info->ndtr1cs0 = ndtr1;
+ nand_writel(info, NDTR0CS0, ndtr0);
+ nand_writel(info, NDTR1CS0, ndtr1);
+}
+
+static int pxa3xx_nand_init_timings(struct pxa3xx_nand_host *host)
+{
+ const struct nand_sdr_timings *timings;
+ struct nand_chip *chip = &host->chip;
+ struct pxa3xx_nand_info *info = host->info_data;
+ const struct pxa3xx_nand_flash *f = NULL;
+ int mode, id, ntypes, i;
+
+ mode = onfi_get_async_timing_mode(chip);
+ if (mode == ONFI_TIMING_MODE_UNKNOWN) {
+ ntypes = ARRAY_SIZE(builtin_flash_types);
+
+ chip->cmdfunc(host->mtd, NAND_CMD_READID, 0x00, -1);
+
+ id = chip->read_byte(host->mtd);
+ id |= chip->read_byte(host->mtd) << 0x8;
+
+ for (i = 0; i < ntypes; i++) {
+ f = &builtin_flash_types[i];
+
+ if (f->chip_id == id)
+ break;
+ }
+
+ if (i == ntypes) {
+ dev_err(&info->pdev->dev, "Error: timings not found\n");
+ return -EINVAL;
+ }
+
+ pxa3xx_nand_set_timing(host, f->timing);
+
+ if (f->flash_width == 16) {
+ info->reg_ndcr |= NDCR_DWIDTH_M;
+ chip->options |= NAND_BUSWIDTH_16;
+ }
+
+ info->reg_ndcr |= (f->dfc_width == 16) ? NDCR_DWIDTH_C : 0;
+ } else {
+ mode = fls(mode) - 1;
+ if (mode < 0)
+ mode = 0;
+
+ timings = onfi_async_timing_mode_to_sdr_timings(mode);
+ if (IS_ERR(timings))
+ return PTR_ERR(timings);
+
+ pxa3xx_nand_set_sdr_timing(host, timings);
+ }
+
+ return 0;
+}
+
/*
* Set the data and OOB size, depending on the selected
* spare and ECC configuration.
--
2.4.0


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