Based on Linux commit 1dfac31a5a63ac04a9b5fbc3f5105a586560f191
This commit improves the ->setup_data_interface() hook.
The denali_setup_data_interface() needs the frequency of clk_x and the ratio of clk_x / clk.
The latter is currently hardcoded in the driver, like this:
#define DENALI_CLK_X_MULT 6
The IP datasheet requires that clk_x / clk be 4, 5, or 6. I just chose 6 because it is the most defensive value, but it is not optimal. By getting the clock rate of both "clk" and "clk_x", the driver can compute the timing values more precisely.
To not break the existing platforms, the fallback value, 50 MHz is provided. It is true for all upstreamed platforms.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
drivers/mtd/nand/raw/denali.c | 47 ++++++++++++++++++++-------------------- drivers/mtd/nand/raw/denali.h | 1 + drivers/mtd/nand/raw/denali_dt.c | 2 ++ 3 files changed, 26 insertions(+), 24 deletions(-)
diff --git a/drivers/mtd/nand/raw/denali.c b/drivers/mtd/nand/raw/denali.c index d1cac06..bbfa3b6 100644 --- a/drivers/mtd/nand/raw/denali.c +++ b/drivers/mtd/nand/raw/denali.c @@ -69,14 +69,6 @@ static int dma_mapping_error(void *dev, dma_addr_t addr) #define DENALI_INVALID_BANK -1 #define DENALI_NR_BANKS 4
-/* - * The bus interface clock, clk_x, is phase aligned with the core clock. The - * clk_x is an integral multiple N of the core clk. The value N is configured - * at IP delivery time, and its available value is 4, 5, or 6. We need to align - * to the largest value to make it work with any possible configuration. - */ -#define DENALI_CLK_X_MULT 6 - static inline struct denali_nand_info *mtd_to_denali(struct mtd_info *mtd) { return container_of(mtd_to_nand(mtd), struct denali_nand_info, nand); @@ -946,7 +938,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, { struct denali_nand_info *denali = mtd_to_denali(mtd); const struct nand_sdr_timings *timings; - unsigned long t_clk; + unsigned long t_x, mult_x; int acc_clks, re_2_we, re_2_re, we_2_re, addr_2_data; int rdwr_en_lo, rdwr_en_hi, rdwr_en_lo_hi, cs_setup; int addr_2_data_mask; @@ -957,15 +949,24 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, return PTR_ERR(timings);
/* clk_x period in picoseconds */ - t_clk = DIV_ROUND_DOWN_ULL(1000000000000ULL, denali->clk_x_rate); - if (!t_clk) + t_x = DIV_ROUND_DOWN_ULL(1000000000000ULL, denali->clk_x_rate); + if (!t_x) + return -EINVAL; + + /* + * The bus interface clock, clk_x, is phase aligned with the core clock. + * The clk_x is an integral multiple N of the core clk. The value N is + * configured at IP delivery time, and its available value is 4, 5, 6. + */ + mult_x = DIV_ROUND_CLOSEST_ULL(denali->clk_x_rate, denali->clk_rate); + if (mult_x < 4 || mult_x > 6) return -EINVAL;
if (chipnr == NAND_DATA_IFACE_CHECK_ONLY) return 0;
/* tREA -> ACC_CLKS */ - acc_clks = DIV_ROUND_UP(timings->tREA_max, t_clk); + acc_clks = DIV_ROUND_UP(timings->tREA_max, t_x); acc_clks = min_t(int, acc_clks, ACC_CLKS__VALUE);
tmp = ioread32(denali->reg + ACC_CLKS); @@ -974,7 +975,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, iowrite32(tmp, denali->reg + ACC_CLKS);
/* tRWH -> RE_2_WE */ - re_2_we = DIV_ROUND_UP(timings->tRHW_min, t_clk); + re_2_we = DIV_ROUND_UP(timings->tRHW_min, t_x); re_2_we = min_t(int, re_2_we, RE_2_WE__VALUE);
tmp = ioread32(denali->reg + RE_2_WE); @@ -983,7 +984,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, iowrite32(tmp, denali->reg + RE_2_WE);
/* tRHZ -> RE_2_RE */ - re_2_re = DIV_ROUND_UP(timings->tRHZ_max, t_clk); + re_2_re = DIV_ROUND_UP(timings->tRHZ_max, t_x); re_2_re = min_t(int, re_2_re, RE_2_RE__VALUE);
tmp = ioread32(denali->reg + RE_2_RE); @@ -997,8 +998,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, * With WE_2_RE properly set, the Denali controller automatically takes * care of the delay; the driver need not set NAND_WAIT_TCCS. */ - we_2_re = DIV_ROUND_UP(max(timings->tCCS_min, timings->tWHR_min), - t_clk); + we_2_re = DIV_ROUND_UP(max(timings->tCCS_min, timings->tWHR_min), t_x); we_2_re = min_t(int, we_2_re, TWHR2_AND_WE_2_RE__WE_2_RE);
tmp = ioread32(denali->reg + TWHR2_AND_WE_2_RE); @@ -1013,7 +1013,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, if (denali->revision < 0x0501) addr_2_data_mask >>= 1;
- addr_2_data = DIV_ROUND_UP(timings->tADL_min, t_clk); + addr_2_data = DIV_ROUND_UP(timings->tADL_min, t_x); addr_2_data = min_t(int, addr_2_data, addr_2_data_mask);
tmp = ioread32(denali->reg + TCWAW_AND_ADDR_2_DATA); @@ -1023,7 +1023,7 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr,
/* tREH, tWH -> RDWR_EN_HI_CNT */ rdwr_en_hi = DIV_ROUND_UP(max(timings->tREH_min, timings->tWH_min), - t_clk); + t_x); rdwr_en_hi = min_t(int, rdwr_en_hi, RDWR_EN_HI_CNT__VALUE);
tmp = ioread32(denali->reg + RDWR_EN_HI_CNT); @@ -1032,11 +1032,10 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, iowrite32(tmp, denali->reg + RDWR_EN_HI_CNT);
/* tRP, tWP -> RDWR_EN_LO_CNT */ - rdwr_en_lo = DIV_ROUND_UP(max(timings->tRP_min, timings->tWP_min), - t_clk); + rdwr_en_lo = DIV_ROUND_UP(max(timings->tRP_min, timings->tWP_min), t_x); rdwr_en_lo_hi = DIV_ROUND_UP(max(timings->tRC_min, timings->tWC_min), - t_clk); - rdwr_en_lo_hi = max(rdwr_en_lo_hi, DENALI_CLK_X_MULT); + t_x); + rdwr_en_lo_hi = max_t(int, rdwr_en_lo_hi, mult_x); rdwr_en_lo = max(rdwr_en_lo, rdwr_en_lo_hi - rdwr_en_hi); rdwr_en_lo = min_t(int, rdwr_en_lo, RDWR_EN_LO_CNT__VALUE);
@@ -1046,8 +1045,8 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, iowrite32(tmp, denali->reg + RDWR_EN_LO_CNT);
/* tCS, tCEA -> CS_SETUP_CNT */ - cs_setup = max3((int)DIV_ROUND_UP(timings->tCS_min, t_clk) - rdwr_en_lo, - (int)DIV_ROUND_UP(timings->tCEA_max, t_clk) - acc_clks, + cs_setup = max3((int)DIV_ROUND_UP(timings->tCS_min, t_x) - rdwr_en_lo, + (int)DIV_ROUND_UP(timings->tCEA_max, t_x) - acc_clks, 0); cs_setup = min_t(int, cs_setup, CS_SETUP_CNT__VALUE);
diff --git a/drivers/mtd/nand/raw/denali.h b/drivers/mtd/nand/raw/denali.h index 9b797be..019deda 100644 --- a/drivers/mtd/nand/raw/denali.h +++ b/drivers/mtd/nand/raw/denali.h @@ -292,6 +292,7 @@ struct udevice;
struct denali_nand_info { struct nand_chip nand; + unsigned long clk_rate; /* core clock rate */ unsigned long clk_x_rate; /* bus interface clock rate */ int active_bank; /* currently selected bank */ struct udevice *dev; diff --git a/drivers/mtd/nand/raw/denali_dt.c b/drivers/mtd/nand/raw/denali_dt.c index f9eadb4..d384b97 100644 --- a/drivers/mtd/nand/raw/denali_dt.c +++ b/drivers/mtd/nand/raw/denali_dt.c @@ -118,6 +118,7 @@ static int denali_dt_probe(struct udevice *dev) }
if (clk_x.dev) { + denali->clk_rate = clk_get_rate(&clk); denali->clk_x_rate = clk_get_rate(&clk_x); } else { /* @@ -126,6 +127,7 @@ static int denali_dt_probe(struct udevice *dev) */ dev_notice(dev, "necessary clock is missing. default clock rates are used.\n"); + denali->clk_rate = 50000000; denali->clk_x_rate = 200000000; }