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Software for White Rabbit PTP Core
Commit 3d2a24cc authored by Theodor-Adrian Stana's avatar Theodor-Adrian Stana Committed by Grzegorz Daniluk
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flash-lowlevel: added delays and made an optimization 

The optimization is the removal of the retval variable in
bbspi_transfer() and using the val parameter as a "shift register"
that is returned at the end of the function.
Signed-off-by: Theodor-Adrian Stana's avatarTheodor Stana <t.stana@cern.ch>
parent dd3a5120
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Showing with 47 additions and 9 deletions
dev/flash.c
View file @ 3d2a24cc
...@@ -11,10 +11,29 @@ ...@@ -11,10 +11,29 @@
* version: 1.0 * version: 1.0
* *
* description: * description:
* This file provides interface functions to access the M25P32 flash chip
* on-board SPEC cards. These functions can also be used to access other
* flash chips from the M25P family, such as the M25P128 available on the
* SVEC cards.
*
* Apart from that, it offers functions for working with an SDB file system
* present on such chips. The file-system must previously be created using
* the gensdbfs tool [1], and uploaded by writing to the flash, using the
* flash-write tool [2]. Then, the SDB file system can be checked using
* the flash_sdb_check function below.
* *
* dependencies: * dependencies:
* libsdbfs.h - the SDBFS library providing the SDB file system structure and
* functions to scan for an SDB file system
* syscon.h - contains the low-level GPIO access functions
* *
* references: * references:
* [1] - Alessandro Rubini -- A Flash file-system based on SDB data
* Structures, Sept. 2012
* http://www.ohwr.org/attachments/download/1594/sdbfs-2012-09-19.pdf
* [2] - sdbfs.README file, obtained by downloading the repository at
* http://www.ohwr.org/projects/wrpc-sw/repository
* and navigating to the tools/ folder
* *
*============================================================================== *==============================================================================
* GNU LESSER GENERAL PUBLIC LICENSE * GNU LESSER GENERAL PUBLIC LICENSE
...@@ -48,13 +67,25 @@ ...@@ -48,13 +67,25 @@
/*****************************************************************************/ /*****************************************************************************/
/* Flash interface */ /* Flash interface */
/*****************************************************************************/ /*****************************************************************************/
/*
* Delay function - limit SPI clock speed to 10 MHz
*/
static void delay()
{
int i;
for (i = 0; i < (int)(CPU_CLOCK/10000000); i++)
asm volatile ("nop");
}
/* /*
* Bit-bang SPI transfer function * Bit-bang SPI transfer function
*/ */
static uint8_t bbspi_transfer(int cspin, uint8_t val) static uint8_t bbspi_transfer(int cspin, uint8_t val)
{ {
int i, retval = 0; int i;
gpio_out(GPIO_SPI_NCS, cspin); gpio_out(GPIO_SPI_NCS, cspin);
delay();
for (i = 0; i < 8; i++) { for (i = 0; i < 8; i++) {
gpio_out(GPIO_SPI_SCLK, 0); gpio_out(GPIO_SPI_SCLK, 0);
if (val & 0x80) { if (val & 0x80) {
...@@ -63,15 +94,16 @@ static uint8_t bbspi_transfer(int cspin, uint8_t val) ...@@ -63,15 +94,16 @@ static uint8_t bbspi_transfer(int cspin, uint8_t val)
else { else {
gpio_out(GPIO_SPI_MOSI, 0); gpio_out(GPIO_SPI_MOSI, 0);
} }
delay();
gpio_out(GPIO_SPI_SCLK, 1); gpio_out(GPIO_SPI_SCLK, 1);
retval <<= 1;
retval |= gpio_in(GPIO_SPI_MISO);
val <<= 1; val <<= 1;
val |= gpio_in(GPIO_SPI_MISO);
delay();
} }
gpio_out(GPIO_SPI_SCLK, 0); gpio_out(GPIO_SPI_SCLK, 0);
return retval; return val;
} }
/* /*
...@@ -218,7 +250,14 @@ int flash_sdb_check() ...@@ -218,7 +250,14 @@ int flash_sdb_check()
uint32_t magic = 0; uint32_t magic = 0;
int i; int i;
uint32_t entry_point[6] = {0x000000, 0x100, 0x200, 0x300, 0x170000, 0x2e0000}; uint32_t entry_point[6] = {
0x000000, // flash base
0x100, // second page in flash
0x200, // IPMI with MultiRecord
0x300, // IPMI with larger MultiRecord
0x170000, // after first FPGA bitstream
0x2e0000 // after MultiBoot bitstream
};
for (i = 0; i < ARRAY_SIZE(entry_point); i++) { for (i = 0; i < ARRAY_SIZE(entry_point); i++) {
flash_read(entry_point[i], (uint8_t *)&magic, 4); flash_read(entry_point[i], (uint8_t *)&magic, 4);
......
tools/flash-host/flash.c
View file @ 3d2a24cc
...@@ -91,7 +91,7 @@ static void delay() ...@@ -91,7 +91,7 @@ static void delay()
*/ */
static uint8_t bbspi_transfer(uint8_t cspin, uint8_t val) static uint8_t bbspi_transfer(uint8_t cspin, uint8_t val)
{ {
uint8_t i, retval = 0; uint8_t i;
gpio_out(GPIO_SPI_NCS, cspin); gpio_out(GPIO_SPI_NCS, cspin);
delay(); delay();
for (i = 0; i < 8; i++) { for (i = 0; i < 8; i++) {
...@@ -104,15 +104,14 @@ static uint8_t bbspi_transfer(uint8_t cspin, uint8_t val) ...@@ -104,15 +104,14 @@ static uint8_t bbspi_transfer(uint8_t cspin, uint8_t val)
} }
delay(); delay();
gpio_out(GPIO_SPI_SCLK, 1); gpio_out(GPIO_SPI_SCLK, 1);
retval <<= 1;
retval |= gpio_in(GPIO_SPI_MISO);
val <<= 1; val <<= 1;
val |= gpio_in(GPIO_SPI_MISO);
delay(); delay();
} }
gpio_out(GPIO_SPI_SCLK, 0); gpio_out(GPIO_SPI_SCLK, 0);
return retval; return val;
} }
/* /*
......
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