diff options
Diffstat (limited to 'bus.c')
| -rw-r--r-- | bus.c | 65 |
1 files changed, 44 insertions, 21 deletions
@@ -151,15 +151,6 @@ static void gpmc_printinfo() } -// The shift amounts - -#define CSWROFFTIME 16 -#define CSRDOFFTIME 8 -#define OEOFFTIME 8 -#define RDACCESSTIME 16 -#define WRCYCLETIME 8 -#define RDCYCLETIME 0 -#define WRACCESSTIME 24 #define BIDIR 0x20 #define PULL_UP 0x10 @@ -175,9 +166,42 @@ static void gpmc_printinfo() #define MODE_7 0x07 -static void gpmc_setup(int chipselect, int accesscycles, int size, bool enablecs, int baseaddress) -{ +// multiply by 10 ns +#define TOTAL_IO_CYCLE 25; // 250 ns cycle +#define CS_DELAY 2; // CS low 20ns after address valid +#define DELAY_TO_WR_RD 4; // RD/WR lines low 50ns after address valid +#define WR_RD_WIDTH 20; // stay low for until 200 ns after address valid +#define DATA_READY 15; // data ready 150ns after address valid + +static void gpmc_setup(void) +{ + int chipselect = 0; + int size = GPMC_SIZE_16MB; + bool enablecs = true; + int baseaddress = 1; + + + int CSWROFFTIME = TOTAL_IO_CYCLE - CS_DELAY; + int CSRDOFFTIME = TOTAL_IO_CYCLE - CS_DELAY; + int CSONTIME = CS_DELAY; + int config2 = (CSWROFFTIME << 16) | (CSRDOFFTIME << 8) | CSONTIME; + + int WEOFFTIME = DELAY_TO_WR_RD + WR_RD_WIDTH; + int WEONTIME = DELAY_TO_WR_RD; + int OEOFFTIME = DELAY_TO_WR_RD + WR_RD_WIDTH; + int OEONTIME = DELAY_TO_WR_RD; + int config4 = (WEOFFTIME << 24) | (WEONTIME << 16) | (OEOFFTIME << 8) | OEONTIME; + + int RDACCESSTIME = DATA_READY; + int WRCYCLETIME = TOTAL_IO_CYCLE; + int RDCYCLETIME = TOTAL_IO_CYCLE; + int config5 = (RDACCESSTIME << 16) | (WRCYCLETIME << 8) | RDCYCLETIME; + + int WRACCESSTIME = DATA_READY; + int config6 = WRACCESSTIME << 24; + + pinmux_configurepin("gpmc_csn0", PULL_UP | MODE_0); pinmux_configurepin("gpmc_oen_ren", PULL_UP | MODE_0); pinmux_configurepin("gpmc_wen", PULL_UP | MODE_0); @@ -209,12 +233,11 @@ static void gpmc_setup(int chipselect, int accesscycles, int size, bool enablecs *(registers + displacement + GPMC_CONFIG7) = 0x0; *(registers + displacement + GPMC_CONFIG1) = 0x0; - *(registers + displacement + GPMC_CONFIG2) = (accesscycles << CSWROFFTIME) | (accesscycles << CSRDOFFTIME); + *(registers + displacement + GPMC_CONFIG2) = config2; *(registers + displacement + GPMC_CONFIG3) = 0x0; // not using ADV so we can ignore this guy - *(registers + displacement + GPMC_CONFIG4) = (accesscycles << OEOFFTIME); - *(registers + displacement + GPMC_CONFIG5) = (accesscycles << RDACCESSTIME) | (accesscycles << WRCYCLETIME) - | (accesscycles << RDCYCLETIME); - *(registers + displacement + GPMC_CONFIG6) = (accesscycles << WRACCESSTIME); + *(registers + displacement + GPMC_CONFIG4) = config4; + *(registers + displacement + GPMC_CONFIG5) = config5; + *(registers + displacement + GPMC_CONFIG6) = config6; *(registers + displacement + GPMC_CONFIG7) = size << 8 | (enablecs ? 1 << 6 : 0) | baseaddress; gpmc_unmapregisters(); @@ -326,7 +349,7 @@ static unsigned gpio_pins[] = { GPIO0_X + 22, // i.e., GPIO0_22 GPIO1_X + 15, // i.e., GPIO1_15 GPIO1_X + 14, GPIO0_X + 27, - GPIO1_X + 12 + GPIO1_X + 12 }; @@ -343,7 +366,7 @@ void bus_init() } if (isbb) { - gpmc_setup(0, GPMCACCESSTIME, GPMC_SIZE_16MB, true, 1); + gpmc_setup(); extbus = (uint8_t*) util_mapmemoryblock(0x01000000, 0x100); @@ -367,9 +390,9 @@ void bus_init() int bus_getpin(int pin) { - if (isbb) { - return gpio_readvalue(gpio_pins[pin]); - } else { + if (isbb) { + return gpio_readvalue(gpio_pins[pin]); + } else { return 0; } } |