Actually the sdram memory on stm32f746 discovery board is micron part MT48LC_4M32_B2B5_6A. This patch does the modification required in the device tree node & driver for the same.
Also we are passing here all the timing parameters in terms of clock cycles, so no need to convert time(ns or ms) to cycles.
Signed-off-by: Vikas Manocha vikas.manocha@st.com cc: Christophe KERELLO christophe.kerello@st.com --- Changed in v4: None Changed in v3: None Changed in v2: None
arch/arm/dts/stm32f746-disco.dts | 13 +++++--- drivers/ram/stm32_sdram.c | 55 ++++++++++---------------------- include/configs/stm32f746-disco.h | 1 - include/dt-bindings/memory/stm32-sdram.h | 15 +++++---- 4 files changed, 33 insertions(+), 51 deletions(-)
diff --git a/arch/arm/dts/stm32f746-disco.dts b/arch/arm/dts/stm32f746-disco.dts index 8e4576b..e720ff1 100644 --- a/arch/arm/dts/stm32f746-disco.dts +++ b/arch/arm/dts/stm32f746-disco.dts @@ -106,12 +106,15 @@ status = "okay";
mr-nbanks = <1>; - /* sdram memory configuration from sdram datasheet IS42S16400J */ + /* Memory configuration from sdram datasheet MT48LC_4M32_B2B5-6A */ bank1: bank@0 { - st,sdram-control = /bits/ 8 <NO_COL_8 NO_ROW_12 MWIDTH_16 BANKS_2 - CAS_3 RD_BURST_EN RD_PIPE_DL_0>; - st,sdram-timing = /bits/ 8 <TMRD_1 TXSR_60 TRAS_42 TRC_60 TRP_18 - TRCD_18>; + st,sdram-control = /bits/ 8 <NO_COL_8 NO_ROW_12 MWIDTH_16 BANKS_4 + CAS_3 SDCLK_2 RD_BURST_EN + RD_PIPE_DL_0>; + st,sdram-timing = /bits/ 8 <TMRD_2 TXSR_6 TRAS_4 TRC_6 TWR_2 + TRP_2 TRCD_2>; + /* refcount = (64msec/total_row_sdram)*freq - 20 */ + st,sdram-refcount = < 1542 >; }; };
diff --git a/drivers/ram/stm32_sdram.c b/drivers/ram/stm32_sdram.c index 5e09f35..48b4979 100644 --- a/drivers/ram/stm32_sdram.c +++ b/drivers/ram/stm32_sdram.c @@ -21,6 +21,7 @@ struct stm32_sdram_control { u8 memory_width; u8 no_banks; u8 cas_latency; + u8 sdclk; u8 rd_burst; u8 rd_pipe_delay; }; @@ -31,51 +32,25 @@ struct stm32_sdram_timing { u8 tras; u8 trc; u8 trp; + u8 twr; u8 trcd; }; struct stm32_sdram_params { u8 no_sdram_banks; struct stm32_sdram_control sdram_control; struct stm32_sdram_timing sdram_timing; + u32 sdram_ref_count; }; -static inline u32 _ns2clk(u32 ns, u32 freq) -{ - u32 tmp = freq/1000000; - return (tmp * ns) / 1000; -} - -#define NS2CLK(ns) (_ns2clk(ns, freq)) - -#define SDRAM_TREF (NS2CLK(64000000 / 8192) - 20)
#define SDRAM_MODE_BL_SHIFT 0 #define SDRAM_MODE_CAS_SHIFT 4 #define SDRAM_MODE_BL 0 -#define SDRAM_MODE_CAS 3 - -#define SDRAM_TRDL 12
int stm32_sdram_init(struct udevice *dev) { - u32 freq; - u32 sdram_twr; struct stm32_sdram_params *params = dev_get_platdata(dev);
- /* - * Get frequency for NS2CLK calculation. - */ - freq = clock_get(CLOCK_AHB) / CONFIG_SYS_RAM_FREQ_DIV; - debug("%s, sdram freq = %d\n", __func__, freq); - - /* Last data in to row precharge, need also comply ineq on page 1648 */ - sdram_twr = max( - max(SDRAM_TRDL, params->sdram_timing.tras - - params->sdram_timing.trcd), - params->sdram_timing.trc - params->sdram_timing.trcd - - params->sdram_timing.trp - ); - - writel(CONFIG_SYS_RAM_FREQ_DIV << FMC_SDCR_SDCLK_SHIFT + writel(params->sdram_control.sdclk << FMC_SDCR_SDCLK_SHIFT | params->sdram_control.cas_latency << FMC_SDCR_CAS_SHIFT | params->sdram_control.no_banks << FMC_SDCR_NB_SHIFT | params->sdram_control.memory_width << FMC_SDCR_MWID_SHIFT @@ -85,13 +60,13 @@ int stm32_sdram_init(struct udevice *dev) | params->sdram_control.rd_burst << FMC_SDCR_RBURST_SHIFT, &STM32_SDRAM_FMC->sdcr1);
- writel(NS2CLK(params->sdram_timing.trcd) << FMC_SDTR_TRCD_SHIFT - | NS2CLK(params->sdram_timing.trp) << FMC_SDTR_TRP_SHIFT - | NS2CLK(sdram_twr) << FMC_SDTR_TWR_SHIFT - | NS2CLK(params->sdram_timing.trc) << FMC_SDTR_TRC_SHIFT - | NS2CLK(params->sdram_timing.tras) << FMC_SDTR_TRAS_SHIFT - | NS2CLK(params->sdram_timing.txsr) << FMC_SDTR_TXSR_SHIFT - | NS2CLK(params->sdram_timing.tmrd) << FMC_SDTR_TMRD_SHIFT, + writel(params->sdram_timing.trcd << FMC_SDTR_TRCD_SHIFT + | params->sdram_timing.trp << FMC_SDTR_TRP_SHIFT + | params->sdram_timing.twr << FMC_SDTR_TWR_SHIFT + | params->sdram_timing.trc << FMC_SDTR_TRC_SHIFT + | params->sdram_timing.tras << FMC_SDTR_TRAS_SHIFT + | params->sdram_timing.txsr << FMC_SDTR_TXSR_SHIFT + | params->sdram_timing.tmrd << FMC_SDTR_TMRD_SHIFT, &STM32_SDRAM_FMC->sdtr1);
writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_START_CLOCK, @@ -110,7 +85,7 @@ int stm32_sdram_init(struct udevice *dev) FMC_BUSY_WAIT();
writel(FMC_SDCMR_BANK_1 | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT - | SDRAM_MODE_CAS << SDRAM_MODE_CAS_SHIFT) + | params->sdram_control.cas_latency << SDRAM_MODE_CAS_SHIFT) << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE, &STM32_SDRAM_FMC->sdcmr); udelay(100); @@ -121,7 +96,7 @@ int stm32_sdram_init(struct udevice *dev) FMC_BUSY_WAIT();
/* Refresh timer */ - writel(SDRAM_TREF, &STM32_SDRAM_FMC->sdrtr); + writel((params->sdram_ref_count) << 1, &STM32_SDRAM_FMC->sdrtr);
return 0; } @@ -142,12 +117,14 @@ static int stm32_fmc_ofdata_to_platdata(struct udevice *dev) sizeof(params->sdram_control)); if (ret) return ret; - ret = fdtdec_get_byte_array(blob, node, "st,sdram-timing", (u8 *)¶ms->sdram_timing, sizeof(params->sdram_timing)); if (ret) return ret; + + params->sdram_ref_count = fdtdec_get_int(blob, node, + "st,sdram-refcount", 8196); }
return 0; diff --git a/include/configs/stm32f746-disco.h b/include/configs/stm32f746-disco.h index 73a316d..cc0f8fd 100644 --- a/include/configs/stm32f746-disco.h +++ b/include/configs/stm32f746-disco.h @@ -16,7 +16,6 @@ * Configuration of the external SDRAM memory */ #define CONFIG_NR_DRAM_BANKS 1 -#define CONFIG_SYS_RAM_FREQ_DIV 2 #define CONFIG_SYS_LOAD_ADDR 0xC0400000 #define CONFIG_LOADADDR 0xC0400000
diff --git a/include/dt-bindings/memory/stm32-sdram.h b/include/dt-bindings/memory/stm32-sdram.h index 4cd6c2b..89b719a 100644 --- a/include/dt-bindings/memory/stm32-sdram.h +++ b/include/dt-bindings/memory/stm32-sdram.h @@ -18,17 +18,20 @@ #define CAS_1 0x1 #define CAS_2 0x2 #define CAS_3 0x3 +#define SDCLK_2 0x2 #define RD_BURST_EN 0x1 #define RD_BURST_DIS 0x0 #define RD_PIPE_DL_0 0x0 #define RD_PIPE_DL_1 0x1 #define RD_PIPE_DL_2 0x2
-#define TMRD_1 0x1 -#define TXSR_60 60 -#define TRAS_42 42 -#define TRC_60 60 -#define TRP_18 18 -#define TRCD_18 18 +/* Timing = value +1 cycles */ +#define TMRD_2 (2 - 1) +#define TXSR_6 (6 - 1) +#define TRAS_4 (4 - 1) +#define TRC_6 (6 - 1) +#define TWR_2 (2 - 1) +#define TRP_2 (2 - 1) +#define TRCD_2 (2 - 1)
#endif