//------------------------------------------------------------------------------
// novena-eim.c
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <sys/mman.h>
#include "novena-eim.h"
//------------------------------------------------------------------------------
// Variables
//------------------------------------------------------------------------------
static long mem_page_size = 0;
static int mem_dev_fd = -1;
static void * mem_map_ptr = MAP_FAILED;
static off_t mem_base_addr = 0;
//------------------------------------------------------------------------------
int eim_setup()
//------------------------------------------------------------------------------
{
// register cleanup function
int ok = atexit(_eim_cleanup);
if (ok != 0)
{ printf("ERROR: atexit() failed.\n");
return -1;
}
// determine memory page size to use in mmap()
mem_page_size = sysconf(_SC_PAGESIZE);
if (mem_page_size < 1)
{ printf("ERROR: sysconf(_SC_PAGESIZE) == %ld\n", mem_page_size);
return -1;
}
// try to open memory device
mem_dev_fd = open(MEMORY_DEVICE, O_RDWR | O_SYNC);
if (mem_dev_fd == -1)
{ printf("ERROR: open(%s) failed.\n", MEMORY_DEVICE);
return -1;
}
/* Several blocks in the CPU have common pins, we can use I/O MUX Controller
* to configure what block will actually use I/O pins. We wait EIM module to be able
* to communicate with the on-board FPGA. Let's configure IOMUXC accordingly.
*/
_eim_setup_iomuxc();
/* We need to enable clocking of EIM block in order to be able to use it.
* Let's configure Clock Controller Module accordingly.
*/
_eim_setup_ccm();
/* We need to properly configure EIM mode and all the corresponding parameters.
* That's a lot of code, let's do it now.
*/
_eim_setup_eim();
// done
return 1;
}
//------------------------------------------------------------------------------
void _eim_cleanup()
//------------------------------------------------------------------------------
{
// unmap memory if needed
if (mem_map_ptr != MAP_FAILED)
{ int ok = munmap(mem_map_ptr, mem_page_size);
if (ok != 0) printf("WARNING: munmap() failed.\n");
}
// close memory device if needed
if (mem_dev_fd != -1)
{ int ok = close(mem_dev_fd);
if (ok != 0) printf("WARNING: close() failed.\n");
}
}
//------------------------------------------------------------------------------
void _eim_setup_iomuxc()
//------------------------------------------------------------------------------
{
// create structures
struct IOMUXC_SW_MUX_CTL_PAD_EIM reg_mux; // mux control register
struct IOMUXC_SW_PAD_CTL_PAD_EIM reg_pad; // pad control register
// setup mux control register
reg_mux.mux_mode = IOMUXC_MUX_MODE_ALT0; // ALT0 mode must be used for EIM
reg_mux.sion = 0; // forced input not needed
reg_mux.reserved_3 = 0; // must be 0
reg_mux.reserved_31_5 = 0; // must be 0
// setup pad control register
reg_pad.sre = IOMUXC_PAD_CTL_SRE_FAST; // fast slew rate
reg_pad.dse = IOMUXC_PAD_CTL_DSE_33_OHM; // highest drive strength
reg_pad.speed = IOMUXC_PAD_CTL_SPEED_MEDIUM_10; // medium speed
reg_pad.ode = IOMUXC_PAD_CTL_ODE_DISABLED; // open drain not needed
reg_pad.pke = IOMUXC_PAD_CTL_PKE_DISABLED; // neither pull nor keeper are needed
reg_pad.pue = IOMUXC_PAD_CTL_PUE_PULL; // doesn't matter actually, because PKE is disabled
reg_pad.pus = IOMUXC_PAD_CTL_PUS_100K_OHM_PU; // doesn't matter actually, because PKE is disabled
reg_pad.hys = IOMUXC_PAD_CTL_HYS_DISABLED; // use CMOS, not Schmitt trigger input
reg_pad.reserved_2_1 = 0; // must be 0
reg_pad.reserved_10_8 = 0; // must be 0
reg_pad.reserved_31_17 = 0; // must be 0
// all the pins must be configured to use the same ALT0 mode
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_CS0_B, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_OE_B, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_RW, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_LBA_B, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD00, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD01, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD02, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD03, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD04, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD05, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD06, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD07, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD08, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD09, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD10, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD11, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD12, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD13, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD14, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_AD15, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_WAIT_B, (uint32_t *)®_mux);
eim_write_32(IOMUXC_SW_MUX_CTL_PAD_EIM_BCLK, (uint32_t *)®_mux);
// we need to configure all the I/O pads too
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_CS0_B, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_OE_B, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_RW, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_LBA_B, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD00, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD01, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD02, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD03, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD04, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD05, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD06, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD07, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD08, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD09, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD10, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD11, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD12, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD13, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD14, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_AD15, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_WAIT_B, (uint32_t *)®_pad);
eim_write_32(IOMUXC_SW_PAD_CTL_PAD_EIM_BCLK, (uint32_t *)®_pad);
}
//------------------------------------------------------------------------------
void _eim_setup_ccm()
//------------------------------------------------------------------------------
{
// create structure
struct CCM_CCGR6 ccm_ccgr6;
// read register
eim_read_32(CCM_CCGR6, (uint32_t *)&ccm_ccgr6);
// modify register
ccm_ccgr6.cg0_usboh3 = CCM_CGR_ON_EXCEPT_STOP;
ccm_ccgr6.cg1_usdhc1 = CCM_CGR_OFF;
ccm_ccgr6.cg2_usdhc2 = CCM_CGR_ON_EXCEPT_STOP;
ccm_ccgr6.cg3_usdhc3 = CCM_CGR_ON_EXCEPT_STOP;
ccm_ccgr6.cg3_usdhc4 = CCM_CGR_OFF;
ccm_ccgr6.cg5_eim_slow = CCM_CGR_ON_EXCEPT_STOP;
ccm_ccgr6.cg6_vdoaxiclk = CCM_CGR_OFF;
ccm_ccgr6.cg7_vpu = CCM_CGR_OFF;
ccm_ccgr6.cg8_reserved = 0;
ccm_ccgr6.cg9_reserved = 0;
ccm_ccgr6.cg10_reserved = 0;
ccm_ccgr6.cg11_reserved = 0;
ccm_ccgr6.cg12_reserved = 0;
ccm_ccgr6.cg13_reserved = 0;
ccm_ccgr6.cg14_reserved = 0;
ccm_ccgr6.cg15_reserved = 0;
// write register
eim_write_32(CCM_CCGR6, (uint32_t *)&ccm_ccgr6);
}
//------------------------------------------------------------------------------
void _eim_setup_eim()
//------------------------------------------------------------------------------
{
// create structures
struct EIM_CS_GCR1 gcr1;
struct EIM_CS_GCR2 gcr2;
struct EIM_CS_RCR1 rcr1;
struct EIM_CS_RCR2 rcr2;
struct EIM_CS_WCR1 wcr1;
struct EIM_CS_WCR2 wcr2;
struct EIM_WCR wcr;
struct EIM_WIAR wiar;
struct EIM_EAR ear;
// read all the registers
eim_read_32(EIM_CS0GCR1, (uint32_t *)&gcr1);
eim_read_32(EIM_CS0GCR2, (uint32_t *)&gcr2);
eim_read_32(EIM_CS0RCR1, (uint32_t *)&rcr1);
eim_read_32(EIM_CS0RCR2, (uint32_t *)&rcr2);
eim_read_32(EIM_CS0WCR1, (uint32_t *)&wcr1);
eim_read_32(EIM_CS0WCR2, (uint32_t *)&wcr2);
eim_read_32(EIM_WCR, (uint32_t *)&wcr);
eim_read_32(EIM_WIAR, (uint32_t *)&wiar);
eim_read_32(EIM_EAR, (uint32_t *)&ear);
// manipulate registers as needed
gcr1.csen = 1; // chip select is enabled |
gcr1.swr = 1; // write is sync |
gcr1.srd = 1; // read is sync |
gcr1.mum = 1; // address and data are multiplexed |
gcr1.wfl = 0; // write latency is not fixed |
gcr1.rfl = 0; // read latency is not fixed |
gcr1.cre = 0; // CRE signal not needed |
//gcr1.crep = x; // don't care, CRE not used |
gcr1.bl = 4; // burst length | ?
gcr1.wc = 0; // write is not continuous | ?
gcr1.bcd = 3; // BCLK divisor is 3+1=4 |
gcr1.bcs = 1; // delay from ~CS to BCLK is 1 cycle |
gcr1.dsz = 1; // 16 bits per databeat at DATA[15:0] |
gcr1.sp = 0; // supervisor protection is disabled |
gcr1.csrec = 1; // ~CS recovery is 1 cycle |
gcr1.aus = 1; // address is not shifted |
gcr1.gbc = 1; // ~CS gap is 1 cycle |
gcr1.wp = 0; // write protection is not enabled |
//gcr1.psz = x; // don't care, page mode is not used |
gcr2.adh = 0; // address hold duration is 1 cycle |
//gcr2.daps = x; // don't care, DTACK is not used |
gcr2.dae = 0; // DTACK is not used |
//gcr2.dap = x; // don't care, DTACK is not used |
gcr2.mux16_byp_grant = 1; // enable grant mechanism | ?
gcr2.reserved_3_2 = 0; // must be 0 |
gcr2.reserved_11_10 = 0; // must be 0 |
gcr2.reserved_31_13 = 0; // must be 0 |
//rcr1.rcsn = x; // don't care in sync mode |
rcr1.rcsa = 0; // no delay for ~CS needed |
//rcr1.oen = x; // don't care in sync mode |
rcr1.oea = 0; // no delay for ~OE needed |
rcr1.radvn = 0; // no delay for ~LBA needed |
rcr1.ral = 0; // clear ~LBA when needed |
rcr1.radva = 0; // no delay for ~LBA needed |
rcr1.rwsc = 1; // one wait state |
rcr1.reserved_3 = 0; // must be 0 |
rcr1.reserved_7 = 0; // must be 0 |
rcr1.reserved_11 = 0; // must be 0 |
rcr1.reserved_15 = 0; // must be 0 |
rcr1.reserved_23 = 0; // must be 0 |
rcr1.reserved_31_30 = 0; // must be 0 |
//rcr2.rben = x; // don't care in sync mode |
rcr2.rbe = 0; // BE is disabled |
//rcr2.rbea = x; // don't care when BE is not used |
rcr2.rl = 0; // read latency is 0 | ?
//rcr2.pat = x; // don't care when page read is not used |
rcr2.apr = 0; // page read mode is not used |
rcr2.reserved_7 = 0; // must be 0 |
rcr2.reserved_11_10 = 0; // must be 0 |
rcr2.reserved_31_16 = 0; // must be 0 |
//wcr1.wcsn = x; // don't care in sync mode |
wcr1.wcsa = 0; // no delay for ~CS needed |
//wcr1.wen = x; // don't care in sync mode |
wcr1.wea = 0; // no delay for ~WR_N needed |
//wcr1.wben = x; // don't care in sync mode |
//wcr1.wbea = x; // don't care in sync mode |
wcr1.wadvn = 0; // no delay for ~LBA needed |
wcr1.wadva = 0; // no delay for ~LBA needed |
wcr1.wwsc = 1; // no wait state in needed |
wcr1.wbed = 1; // BE is disabled |
wcr1.wal = 0; // clear ~LBA when needed |
wcr2.wbcdd = 0; // write clock division is not needed |
wcr2.reserved_31_1 = 0; // must be 0 |
wcr.bcm = 0; // clock is only active during access |
//wcr.gbcd = x; // don't care when BCM=0 |
wcr.inten = 0; // interrupt is not used |
//wcr.intpol = x; // don't care when interrupt is not used |
wcr.wdog_en = 1; // watchdog is enabled |
wcr.wdog_limit = 00; // timeout is 128 BCLK cycles |
wcr.reserved_3 = 0; // must be 0 |
wcr.reserved_7_6 = 0; // must be 0 |
wcr.reserved_31_11 = 0; // must be 0 |
wiar.ips_req = 0; // IPS not needed |
wiar.ips_ack = 0; // IPS not needed |
//wiar.irq = x; // don't touch |
//wiar.errst = x; // don't touch |
wiar.aclk_en = 1; // clock is enabled |
wiar.reserved_31_5 = 0; // must be 0 |
//ear.error_addr = x; // read-only |
// write modified registers
eim_write_32(EIM_CS0GCR1, (uint32_t *)&gcr1);
eim_write_32(EIM_CS0GCR2, (uint32_t *)&gcr2);
eim_write_32(EIM_CS0RCR1, (uint32_t *)&rcr1);
eim_write_32(EIM_CS0RCR2, (uint32_t *)&rcr2);
eim_write_32(EIM_CS0WCR1, (uint32_t *)&wcr1);
eim_write_32(EIM_CS0WCR2, (uint32_t *)&wcr2);
eim_write_32(EIM_WCR, (uint32_t *)&wcr);
eim_write_32(EIM_WIAR, (uint32_t *)&wiar);/*
eim_write_32(EIM_EAR, (uint32_t *)&ear);*/
}
//------------------------------------------------------------------------------
void eim_write_32(off_t offset, uint32_t *pvalue)
//------------------------------------------------------------------------------
{
// calculate memory offset
uint32_t *ptr = (uint32_t *)_eim_calc_offset(offset);
// write data to memory
memcpy(ptr, pvalue, sizeof(uint32_t));
}
//------------------------------------------------------------------------------
void eim_read_32(off_t offset, uint32_t *pvalue)
//------------------------------------------------------------------------------
{
// calculate memory offset
uint32_t *ptr = (uint32_t *)_eim_calc_offset(offset);
// read data from memory
memcpy(pvalue, ptr, sizeof(uint32_t));
}
//------------------------------------------------------------------------------
off_t _eim_calc_offset(off_t offset)
//------------------------------------------------------------------------------
{
// make sure that memory is mapped
if (mem_map_ptr == MAP_FAILED) _eim_remap_mem(offset);
// calculate starting and ending addresses of currently mapped page
off_t offset_low = mem_base_addr;
off_t offset_high = mem_base_addr + (mem_page_size - 1);
// check that offset is in currently mapped page, remap new page otherwise
if ((offset < offset_low) || (offset > offset_high)) _eim_remap_mem(offset);
// calculate pointer
return (off_t)mem_map_ptr + (offset - mem_base_addr);
}
//------------------------------------------------------------------------------
void _eim_remap_mem(off_t offset)
//------------------------------------------------------------------------------
{
// unmap old memory page if needed
if (mem_map_ptr != MAP_FAILED)
{ int ok = munmap(mem_map_ptr, mem_page_size);
if (ok != 0)
{ printf("ERROR: munmap() failed.\n");
exit(EXIT_FAILURE);
}
}
// calculate starting address of new page
while (offset % mem_page_size) offset--;
// try to map new memory page
mem_map_ptr = mmap(NULL, mem_page_size, PROT_READ | PROT_WRITE, MAP_SHARED, mem_dev_fd, offset);
if (mem_map_ptr == MAP_FAILED)
{ printf("ERROR: mmap() failed.\n");
exit(EXIT_FAILURE);
}
// save last mapped page address
mem_base_addr = offset;
}
//------------------------------------------------------------------------------
// End-of-File
//------------------------------------------------------------------------------