diff options
Diffstat (limited to 'drivers/mtd/nand/raw/fsmc_nand.c')
| -rw-r--r-- | drivers/mtd/nand/raw/fsmc_nand.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c index 658f0cbe7ce8..6b2bda815b88 100644 --- a/drivers/mtd/nand/raw/fsmc_nand.c +++ b/drivers/mtd/nand/raw/fsmc_nand.c @@ -15,6 +15,7 @@ #include <linux/clk.h> #include <linux/completion.h> +#include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/dma-direction.h> #include <linux/dma-mapping.h> @@ -93,6 +94,14 @@ #define FSMC_BUSY_WAIT_TIMEOUT (1 * HZ) +/* + * According to SPEAr300 Reference Manual (RM0082) + * TOUDEL = 7ns (Output delay from the flip-flops to the board) + * TINDEL = 5ns (Input delay from the board to the flipflop) + */ +#define TOUTDEL 7000 +#define TINDEL 5000 + struct fsmc_nand_timings { u8 tclr; u8 tar; @@ -277,7 +286,7 @@ static int fsmc_calc_timings(struct fsmc_nand_data *host, { unsigned long hclk = clk_get_rate(host->clk); unsigned long hclkn = NSEC_PER_SEC / hclk; - u32 thiz, thold, twait, tset; + u32 thiz, thold, twait, tset, twait_min; if (sdrt->tRC_min < 30000) return -EOPNOTSUPP; @@ -309,13 +318,6 @@ static int fsmc_calc_timings(struct fsmc_nand_data *host, else if (tims->thold > FSMC_THOLD_MASK) tims->thold = FSMC_THOLD_MASK; - twait = max(sdrt->tRP_min, sdrt->tWP_min); - tims->twait = DIV_ROUND_UP(twait / 1000, hclkn) - 1; - if (tims->twait == 0) - tims->twait = 1; - else if (tims->twait > FSMC_TWAIT_MASK) - tims->twait = FSMC_TWAIT_MASK; - tset = max(sdrt->tCS_min - sdrt->tWP_min, sdrt->tCEA_max - sdrt->tREA_max); tims->tset = DIV_ROUND_UP(tset / 1000, hclkn) - 1; @@ -324,6 +326,21 @@ static int fsmc_calc_timings(struct fsmc_nand_data *host, else if (tims->tset > FSMC_TSET_MASK) tims->tset = FSMC_TSET_MASK; + /* + * According to SPEAr300 Reference Manual (RM0082) which gives more + * information related to FSMSC timings than the SPEAr600 one (RM0305), + * twait >= tCEA - (tset * TCLK) + TOUTDEL + TINDEL + */ + twait_min = sdrt->tCEA_max - ((tims->tset + 1) * hclkn * 1000) + + TOUTDEL + TINDEL; + twait = max3(sdrt->tRP_min, sdrt->tWP_min, twait_min); + + tims->twait = DIV_ROUND_UP(twait / 1000, hclkn) - 1; + if (tims->twait == 0) + tims->twait = 1; + else if (tims->twait > FSMC_TWAIT_MASK) + tims->twait = FSMC_TWAIT_MASK; + return 0; } @@ -664,6 +681,9 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op, instr->ctx.waitrdy.timeout_ms); break; } + + if (instr->delay_ns) + ndelay(instr->delay_ns); } return ret; |