u-boot/drivers/spi/atmel_dataflash_spi.c
Axel Lin 7dfc4dbd2d spi: atmel_dataflash: Simplify AT91F_SpiEnable implementation
Refactor the code a bit to make it better in readability.
Remove the comments because now the intention of the code is pretty clear.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
2014-03-17 21:54:57 +05:30

184 lines
4.8 KiB
C

/*
* Driver for ATMEL DataFlash support
* Author : Hamid Ikdoumi (Atmel)
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* This driver desperately needs rework:
*
* - use structure SoC access
* - get rid of including asm/arch/at91_spi.h
* - remove asm/arch/at91_spi.h
* - get rid of all CONFIG_ATMEL_LEGACY defines and uses
*
* 02-Aug-2010 Reinhard Meyer <uboot@emk-elektronik.de>
*/
#include <common.h>
#ifndef CONFIG_ATMEL_LEGACY
# define CONFIG_ATMEL_LEGACY
#endif
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/hardware.h>
#include "atmel_spi.h"
#include <asm/arch/gpio.h>
#include <asm/arch/at91_pio.h>
#include <asm/arch/at91_spi.h>
#include <dataflash.h>
#define AT91_SPI_PCS0_DATAFLASH_CARD 0xE /* Chip Select 0: NPCS0%1110 */
#define AT91_SPI_PCS1_DATAFLASH_CARD 0xD /* Chip Select 1: NPCS1%1101 */
#define AT91_SPI_PCS2_DATAFLASH_CARD 0xB /* Chip Select 2: NPCS2%1011 */
#define AT91_SPI_PCS3_DATAFLASH_CARD 0x7 /* Chip Select 3: NPCS3%0111 */
void AT91F_SpiInit(void)
{
/* Reset the SPI */
writel(AT91_SPI_SWRST, ATMEL_BASE_SPI0 + AT91_SPI_CR);
/* Configure SPI in Master Mode with No CS selected !!! */
writel(AT91_SPI_MSTR | AT91_SPI_MODFDIS | AT91_SPI_PCS,
ATMEL_BASE_SPI0 + AT91_SPI_MR);
/* Configure CS0 */
writel(AT91_SPI_NCPHA |
(AT91_SPI_DLYBS & DATAFLASH_TCSS) |
(AT91_SPI_DLYBCT & DATAFLASH_TCHS) |
((get_mck_clk_rate() / AT91_SPI_CLK) << 8),
ATMEL_BASE_SPI0 + AT91_SPI_CSR(0));
#ifdef CONFIG_SYS_DATAFLASH_LOGIC_ADDR_CS1
/* Configure CS1 */
writel(AT91_SPI_NCPHA |
(AT91_SPI_DLYBS & DATAFLASH_TCSS) |
(AT91_SPI_DLYBCT & DATAFLASH_TCHS) |
((get_mck_clk_rate() / AT91_SPI_CLK) << 8),
ATMEL_BASE_SPI0 + AT91_SPI_CSR(1));
#endif
#ifdef CONFIG_SYS_DATAFLASH_LOGIC_ADDR_CS2
/* Configure CS2 */
writel(AT91_SPI_NCPHA |
(AT91_SPI_DLYBS & DATAFLASH_TCSS) |
(AT91_SPI_DLYBCT & DATAFLASH_TCHS) |
((get_mck_clk_rate() / AT91_SPI_CLK) << 8),
ATMEL_BASE_SPI0 + AT91_SPI_CSR(2));
#endif
#ifdef CONFIG_SYS_DATAFLASH_LOGIC_ADDR_CS3
/* Configure CS3 */
writel(AT91_SPI_NCPHA |
(AT91_SPI_DLYBS & DATAFLASH_TCSS) |
(AT91_SPI_DLYBCT & DATAFLASH_TCHS) |
((get_mck_clk_rate() / AT91_SPI_CLK) << 8),
ATMEL_BASE_SPI0 + AT91_SPI_CSR(3));
#endif
/* SPI_Enable */
writel(AT91_SPI_SPIEN, ATMEL_BASE_SPI0 + AT91_SPI_CR);
while (!(readl(ATMEL_BASE_SPI0 + AT91_SPI_SR) & AT91_SPI_SPIENS))
;
/*
* Add tempo to get SPI in a safe state.
* Should not be needed for new silicon (Rev B)
*/
udelay(500000);
readl(ATMEL_BASE_SPI0 + AT91_SPI_SR);
readl(ATMEL_BASE_SPI0 + AT91_SPI_RDR);
}
void AT91F_SpiEnable(int cs)
{
unsigned long mode;
mode = readl(ATMEL_BASE_SPI0 + AT91_SPI_MR);
mode &= ~AT91_SPI_PCS;
switch (cs) {
case 0:
mode |= AT91_SPI_PCS0_DATAFLASH_CARD << 16;
break;
case 1:
mode |= AT91_SPI_PCS1_DATAFLASH_CARD << 16;
break;
case 2:
mode |= AT91_SPI_PCS2_DATAFLASH_CARD << 16;
break;
case 3:
mode |= AT91_SPI_PCS3_DATAFLASH_CARD << 16;
break;
}
writel(mode, ATMEL_BASE_SPI0 + AT91_SPI_MR);
/* SPI_Enable */
writel(AT91_SPI_SPIEN, ATMEL_BASE_SPI0 + AT91_SPI_CR);
}
unsigned int AT91F_SpiWrite1(AT91PS_DataflashDesc pDesc);
unsigned int AT91F_SpiWrite(AT91PS_DataflashDesc pDesc)
{
unsigned int timeout;
unsigned int timebase;
pDesc->state = BUSY;
writel(AT91_SPI_TXTDIS + AT91_SPI_RXTDIS,
ATMEL_BASE_SPI0 + AT91_SPI_PTCR);
/* Initialize the Transmit and Receive Pointer */
writel((unsigned int)pDesc->rx_cmd_pt,
ATMEL_BASE_SPI0 + AT91_SPI_RPR);
writel((unsigned int)pDesc->tx_cmd_pt,
ATMEL_BASE_SPI0 + AT91_SPI_TPR);
/* Intialize the Transmit and Receive Counters */
writel(pDesc->rx_cmd_size, ATMEL_BASE_SPI0 + AT91_SPI_RCR);
writel(pDesc->tx_cmd_size, ATMEL_BASE_SPI0 + AT91_SPI_TCR);
if (pDesc->tx_data_size != 0) {
/* Initialize the Next Transmit and Next Receive Pointer */
writel((unsigned int)pDesc->rx_data_pt,
ATMEL_BASE_SPI0 + AT91_SPI_RNPR);
writel((unsigned int)pDesc->tx_data_pt,
ATMEL_BASE_SPI0 + AT91_SPI_TNPR);
/* Intialize the Next Transmit and Next Receive Counters */
writel(pDesc->rx_data_size,
ATMEL_BASE_SPI0 + AT91_SPI_RNCR);
writel(pDesc->tx_data_size,
ATMEL_BASE_SPI0 + AT91_SPI_TNCR);
}
/* arm simple, non interrupt dependent timer */
timebase = get_timer(0);
timeout = 0;
writel(AT91_SPI_TXTEN + AT91_SPI_RXTEN,
ATMEL_BASE_SPI0 + AT91_SPI_PTCR);
while (!(readl(ATMEL_BASE_SPI0 + AT91_SPI_SR) & AT91_SPI_RXBUFF) &&
((timeout = get_timer(timebase)) < CONFIG_SYS_SPI_WRITE_TOUT))
;
writel(AT91_SPI_TXTDIS + AT91_SPI_RXTDIS,
ATMEL_BASE_SPI0 + AT91_SPI_PTCR);
pDesc->state = IDLE;
if (timeout >= CONFIG_SYS_SPI_WRITE_TOUT) {
printf("Error Timeout\n\r");
return DATAFLASH_ERROR;
}
return DATAFLASH_OK;
}