Commit 60445cb5 authored by Hans-Christian Egtvedt's avatar Hans-Christian Egtvedt Committed by Wolfgang Denk
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atmel_spi: Driver for the Atmel SPI controller



This adds a driver for the SPI controller found on most AT91 and AVR32
chips, implementing the new SPI API.

Changed in v4:
  - Update to new API
  - Handle zero-length transfers appropriately. The user may send a
    zero-length SPI transfer with SPI_XFER_END set in order to
    deactivate the chip select after a series of transfers with chip
    select active. This is useful e.g. when polling the status
    register of DataFlash.
Signed-off-by: default avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
parent d255bb0e
......@@ -21,8 +21,11 @@
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/chip-features.h>
#include <asm/arch/gpio.h>
#include <asm/arch/memory-map.h>
/*
* Lots of small functions here. We depend on --gc-sections getting
......@@ -142,3 +145,43 @@ void gpio_enable_mmci(void)
gpio_select_periph_A(GPIO_PIN_PA15, 0); /* DATA3 */
}
#endif
#ifdef AT32AP700x_CHIP_HAS_SPI
void gpio_enable_spi0(unsigned long cs_mask)
{
u32 pa_mask = 0;
gpio_select_periph_A(GPIO_PIN_PA0, 0); /* MISO */
gpio_select_periph_A(GPIO_PIN_PA1, 0); /* MOSI */
gpio_select_periph_A(GPIO_PIN_PA2, 0); /* SCK */
if (cs_mask & (1 << 0))
pa_mask |= 1 << 3; /* NPCS0 */
if (cs_mask & (1 << 1))
pa_mask |= 1 << 4; /* NPCS1 */
if (cs_mask & (1 << 2))
pa_mask |= 1 << 5; /* NPCS2 */
if (cs_mask & (1 << 3))
pa_mask |= 1 << 20; /* NPCS3 */
__raw_writel(pa_mask, PIOA_BASE + 0x00);
__raw_writel(pa_mask, PIOA_BASE + 0x30);
__raw_writel(pa_mask, PIOA_BASE + 0x10);
}
void gpio_enable_spi1(unsigned long cs_mask)
{
gpio_select_periph_B(GPIO_PIN_PA0, 0); /* MISO */
gpio_select_periph_B(GPIO_PIN_PB1, 0); /* MOSI */
gpio_select_periph_B(GPIO_PIN_PB5, 0); /* SCK */
if (cs_mask & (1 << 0))
gpio_select_periph_B(GPIO_PIN_PB2, 0); /* NPCS0 */
if (cs_mask & (1 << 1))
gpio_select_periph_B(GPIO_PIN_PB3, 0); /* NPCS1 */
if (cs_mask & (1 << 2))
gpio_select_periph_B(GPIO_PIN_PB4, 0); /* NPCS2 */
if (cs_mask & (1 << 3))
gpio_select_periph_A(GPIO_PIN_PA27, 0); /* NPCS3 */
}
#endif
......@@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk
LIB := $(obj)libspi.a
COBJS-y += mpc8xxx_spi.o
COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
COBJS := $(COBJS-y)
......
/*
* Copyright (C) 2007 Atmel Corporation
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <spi.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/memory-map.h>
#include "atmel_spi.h"
void spi_init()
{
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct atmel_spi_slave *as;
unsigned int scbr;
u32 csrx;
void *regs;
if (cs > 3 || !spi_cs_is_valid(bus, cs))
return NULL;
switch (bus) {
case 0:
regs = (void *)SPI0_BASE;
break;
#ifdef SPI1_BASE
case 1:
regs = (void *)SPI1_BASE;
break;
#endif
#ifdef SPI2_BASE
case 2:
regs = (void *)SPI2_BASE;
break;
#endif
#ifdef SPI3_BASE
case 3:
regs = (void *)SPI3_BASE;
break;
#endif
default:
return NULL;
}
scbr = (get_spi_clk_rate(bus) + max_hz - 1) / max_hz;
if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
/* Too low max SCK rate */
return NULL;
if (scbr < 1)
scbr = 1;
csrx = ATMEL_SPI_CSRx_SCBR(scbr);
csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
if (!(mode & SPI_CPHA))
csrx |= ATMEL_SPI_CSRx_NCPHA;
if (mode & SPI_CPOL)
csrx |= ATMEL_SPI_CSRx_CPOL;
as = malloc(sizeof(struct atmel_spi_slave));
if (!as)
return NULL;
as->slave.bus = bus;
as->slave.cs = cs;
as->regs = regs;
as->mr = ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_MODFDIS
| ATMEL_SPI_MR_PCS(~(1 << cs) & 0xf);
spi_writel(as, CSR(cs), csrx);
return &as->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
free(as);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
/* Enable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIEN);
/*
* Select the slave. This should set SCK to the correct
* initial state, etc.
*/
spi_writel(as, MR, as->mr);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
/* Disable the SPI hardware */
spi_writel(as, CR, ATMEL_SPI_CR_SPIDIS);
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct atmel_spi_slave *as = to_atmel_spi(slave);
unsigned int len_tx;
unsigned int len_rx;
unsigned int len;
int ret;
u32 status;
const u8 *txp = dout;
u8 *rxp = din;
u8 value;
ret = 0;
if (bitlen == 0)
/* Finish any previously submitted transfers */
goto out;
/*
* TODO: The controller can do non-multiple-of-8 bit
* transfers, but this driver currently doesn't support it.
*
* It's also not clear how such transfers are supposed to be
* represented as a stream of bytes...this is a limitation of
* the current SPI interface.
*/
if (bitlen % 8) {
/* Errors always terminate an ongoing transfer */
flags |= SPI_XFER_END;
goto out;
}
len = bitlen / 8;
/*
* The controller can do automatic CS control, but it is
* somewhat quirky, and it doesn't really buy us much anyway
* in the context of U-Boot.
*/
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
for (len_tx = 0, len_rx = 0; len_rx < len; ) {
status = spi_readl(as, SR);
if (status & ATMEL_SPI_SR_OVRES)
return -1;
if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
if (txp)
value = *txp++;
else
value = 0;
spi_writel(as, TDR, value);
len_tx++;
}
if (status & ATMEL_SPI_SR_RDRF) {
value = spi_readl(as, RDR);
if (rxp)
*rxp++ = value;
len_rx++;
}
}
out:
if (flags & SPI_XFER_END) {
/*
* Wait until the transfer is completely done before
* we deactivate CS.
*/
do {
status = spi_readl(as, SR);
} while (!(status & ATMEL_SPI_SR_TXEMPTY));
spi_cs_deactivate(slave);
}
return 0;
}
/*
* Register definitions for the Atmel AT32/AT91 SPI Controller
*/
/* Register offsets */
#define ATMEL_SPI_CR 0x0000
#define ATMEL_SPI_MR 0x0004
#define ATMEL_SPI_RDR 0x0008
#define ATMEL_SPI_TDR 0x000c
#define ATMEL_SPI_SR 0x0010
#define ATMEL_SPI_IER 0x0014
#define ATMEL_SPI_IDR 0x0018
#define ATMEL_SPI_IMR 0x001c
#define ATMEL_SPI_CSR(x) (0x0030 + 4 * (x))
#define ATMEL_SPI_VERSION 0x00fc
/* Bits in CR */
#define ATMEL_SPI_CR_SPIEN (1 << 0)
#define ATMEL_SPI_CR_SPIDIS (1 << 1)
#define ATMEL_SPI_CR_SWRST (1 << 7)
#define ATMEL_SPI_CR_LASTXFER (1 << 24)
/* Bits in MR */
#define ATMEL_SPI_MR_MSTR (1 << 0)
#define ATMEL_SPI_MR_PS (1 << 1)
#define ATMEL_SPI_MR_PCSDEC (1 << 2)
#define ATMEL_SPI_MR_FDIV (1 << 3)
#define ATMEL_SPI_MR_MODFDIS (1 << 4)
#define ATMEL_SPI_MR_LLB (1 << 7)
#define ATMEL_SPI_MR_PCS(x) (((x) & 15) << 16)
#define ATMEL_SPI_MR_DLYBCS(x) ((x) << 24)
/* Bits in RDR */
#define ATMEL_SPI_RDR_RD(x) (x)
#define ATMEL_SPI_RDR_PCS(x) ((x) << 16)
/* Bits in TDR */
#define ATMEL_SPI_TDR_TD(x) (x)
#define ATMEL_SPI_TDR_PCS(x) ((x) << 16)
#define ATMEL_SPI_TDR_LASTXFER (1 << 24)
/* Bits in SR/IER/IDR/IMR */
#define ATMEL_SPI_SR_RDRF (1 << 0)
#define ATMEL_SPI_SR_TDRE (1 << 1)
#define ATMEL_SPI_SR_MODF (1 << 2)
#define ATMEL_SPI_SR_OVRES (1 << 3)
#define ATMEL_SPI_SR_ENDRX (1 << 4)
#define ATMEL_SPI_SR_ENDTX (1 << 5)
#define ATMEL_SPI_SR_RXBUFF (1 << 6)
#define ATMEL_SPI_SR_TXBUFE (1 << 7)
#define ATMEL_SPI_SR_NSSR (1 << 8)
#define ATMEL_SPI_SR_TXEMPTY (1 << 9)
#define ATMEL_SPI_SR_SPIENS (1 << 16)
/* Bits in CSRx */
#define ATMEL_SPI_CSRx_CPOL (1 << 0)
#define ATMEL_SPI_CSRx_NCPHA (1 << 1)
#define ATMEL_SPI_CSRx_CSAAT (1 << 3)
#define ATMEL_SPI_CSRx_BITS(x) ((x) << 4)
#define ATMEL_SPI_CSRx_SCBR(x) ((x) << 8)
#define ATMEL_SPI_CSRx_SCBR_MAX 0xff
#define ATMEL_SPI_CSRx_DLYBS(x) ((x) << 16)
#define ATMEL_SPI_CSRx_DLYBCT(x) ((x) << 24)
/* Bits in VERSION */
#define ATMEL_SPI_VERSION_REV(x) ((x) << 0)
#define ATMEL_SPI_VERSION_MFN(x) ((x) << 16)
/* Constants for CSRx:BITS */
#define ATMEL_SPI_BITS_8 0
#define ATMEL_SPI_BITS_9 1
#define ATMEL_SPI_BITS_10 2
#define ATMEL_SPI_BITS_11 3
#define ATMEL_SPI_BITS_12 4
#define ATMEL_SPI_BITS_13 5
#define ATMEL_SPI_BITS_14 6
#define ATMEL_SPI_BITS_15 7
#define ATMEL_SPI_BITS_16 8
struct atmel_spi_slave {
struct spi_slave slave;
void *regs;
u32 mr;
};
static inline struct atmel_spi_slave *to_atmel_spi(struct spi_slave *slave)
{
return container_of(slave, struct atmel_spi_slave, slave);
}
/* Register access macros */
#define spi_readl(as, reg) \
readl(as->regs + ATMEL_SPI_##reg)
#define spi_writel(as, reg, value) \
writel(value, as->regs + ATMEL_SPI_##reg)
......@@ -25,6 +25,7 @@
/* Currently, all the AP700x chips have these */
#define AT32AP700x_CHIP_HAS_USART
#define AT32AP700x_CHIP_HAS_MMCI
#define AT32AP700x_CHIP_HAS_SPI
/* Only AP7000 has ethernet interface */
#ifdef CONFIG_AT32AP7000
......
......@@ -74,6 +74,12 @@ static inline unsigned long get_mci_clk_rate(void)
return get_pbb_clk_rate();
}
#endif
#ifdef AT32AP700x_CHIP_HAS_SPI
static inline unsigned long get_spi_clk_rate(unsigned int dev_id)
{
return get_pba_clk_rate();
}
#endif
extern void clk_init(void);
......
......@@ -216,5 +216,9 @@ void gpio_enable_macb1(void);
#ifdef AT32AP700x_CHIP_HAS_MMCI
void gpio_enable_mmci(void);
#endif
#ifdef AT32AP700x_CHIP_HAS_SPI
void gpio_enable_spi0(unsigned long cs_mask);
void gpio_enable_spi1(unsigned long cs_mask);
#endif
#endif /* __ASM_AVR32_ARCH_GPIO_H__ */
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