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SPI: Add SPI Driver for EXYNOS.

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This patch adds SPI driver for EXYNOS.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Signed-off-by: Hatim Ali <hatim.rv@samsung.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: jy0922.shim@samsung.com
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
master
Rajeshwari Shinde 12 years ago committed by Minkyu Kang
parent 383b5cc58c
commit 1bf43b829e
3 changed files with 446 additions and 0 deletions
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  1. 78
      arch/arm/include/asm/arch-exynos/spi.h
  2. 1
      drivers/spi/Makefile
  3. 367
      drivers/spi/exynos_spi.c

78
arch/arm/include/asm/arch-exynos/spi.h
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@ -0,0 +1,78 @@
/*
* (C) Copyright 2012 SAMSUNG Electronics
* Padmavathi Venna <padma.v@samsung.com>
*
* 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
*/
#ifndef __ASM_ARCH_EXYNOS_COMMON_SPI_H_
#define __ASM_ARCH_EXYNOS_COMMON_SPI_H_
#ifndef __ASSEMBLY__
/* SPI peripheral register map; padded to 64KB */
struct exynos_spi {
unsigned int ch_cfg; /* 0x00 */
unsigned char reserved0[4];
unsigned int mode_cfg; /* 0x08 */
unsigned int cs_reg; /* 0x0c */
unsigned char reserved1[4];
unsigned int spi_sts; /* 0x14 */
unsigned int tx_data; /* 0x18 */
unsigned int rx_data; /* 0x1c */
unsigned int pkt_cnt; /* 0x20 */
unsigned char reserved2[4];
unsigned char reserved3[4];
unsigned int fb_clk; /* 0x2c */
unsigned char padding[0xffd0];
};
#define EXYNOS_SPI_MAX_FREQ 50000000
#define SPI_TIMEOUT_MS 10
/* SPI_CHCFG */
#define SPI_CH_HS_EN (1 << 6)
#define SPI_CH_RST (1 << 5)
#define SPI_SLAVE_MODE (1 << 4)
#define SPI_CH_CPOL_L (1 << 3)
#define SPI_CH_CPHA_B (1 << 2)
#define SPI_RX_CH_ON (1 << 1)
#define SPI_TX_CH_ON (1 << 0)
/* SPI_MODECFG */
#define SPI_MODE_CH_WIDTH_WORD (0x2 << 29)
#define SPI_MODE_BUS_WIDTH_WORD (0x2 << 17)
/* SPI_CSREG */
#define SPI_SLAVE_SIG_INACT (1 << 0)
/* SPI_STS */
#define SPI_ST_TX_DONE (1 << 25)
#define SPI_FIFO_LVL_MASK 0x1ff
#define SPI_TX_LVL_OFFSET 6
#define SPI_RX_LVL_OFFSET 15
/* Feedback Delay */
#define SPI_CLK_BYPASS (0 << 0)
#define SPI_FB_DELAY_90 (1 << 0)
#define SPI_FB_DELAY_180 (2 << 0)
#define SPI_FB_DELAY_270 (3 << 0)
/* Packet Count */
#define SPI_PACKET_CNT_EN (1 << 16)
#endif /* __ASSEMBLY__ */
#endif

1
drivers/spi/Makefile
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@ -34,6 +34,7 @@ COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o
COBJS-$(CONFIG_CF_SPI) += cf_spi.o
COBJS-$(CONFIG_CF_QSPI) += cf_qspi.o
COBJS-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
COBJS-$(CONFIG_EXYNOS_SPI) += exynos_spi.o
COBJS-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o

367
drivers/spi/exynos_spi.c
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@ -0,0 +1,367 @@
/*
* (C) Copyright 2012 SAMSUNG Electronics
* Padmavathi Venna <padma.v@samsung.com>
*
* 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 <malloc.h>
#include <spi.h>
#include <asm/arch/clk.h>
#include <asm/arch/clock.h>
#include <asm/arch/cpu.h>
#include <asm/arch/gpio.h>
#include <asm/arch/pinmux.h>
#include <asm/arch-exynos/spi.h>
#include <asm/io.h>
/* Information about each SPI controller */
struct spi_bus {
enum periph_id periph_id;
s32 frequency; /* Default clock frequency, -1 for none */
struct exynos_spi *regs;
int inited; /* 1 if this bus is ready for use */
};
/* A list of spi buses that we know about */
static struct spi_bus spi_bus[EXYNOS5_SPI_NUM_CONTROLLERS];
struct exynos_spi_slave {
struct spi_slave slave;
struct exynos_spi *regs;
unsigned int freq; /* Default frequency */
unsigned int mode;
enum periph_id periph_id; /* Peripheral ID for this device */
unsigned int fifo_size;
};
static struct spi_bus *spi_get_bus(unsigned dev_index)
{
if (dev_index < EXYNOS5_SPI_NUM_CONTROLLERS)
return &spi_bus[dev_index];
debug("%s: invalid bus %d", __func__, dev_index);
return NULL;
}
static inline struct exynos_spi_slave *to_exynos_spi(struct spi_slave *slave)
{
return container_of(slave, struct exynos_spi_slave, slave);
}
/**
* Setup the driver private data
*
* @param bus ID of the bus that the slave is attached to
* @param cs ID of the chip select connected to the slave
* @param max_hz Required spi frequency
* @param mode Required spi mode (clk polarity, clk phase and
* master or slave)
* @return new device or NULL
*/
struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct exynos_spi_slave *spi_slave;
struct spi_bus *bus;
if (!spi_cs_is_valid(busnum, cs)) {
debug("%s: Invalid bus/chip select %d, %d\n", __func__,
busnum, cs);
return NULL;
}
spi_slave = malloc(sizeof(*spi_slave));
if (!spi_slave) {
debug("%s: Could not allocate spi_slave\n", __func__);
return NULL;
}
bus = &spi_bus[busnum];
spi_slave->slave.bus = busnum;
spi_slave->slave.cs = cs;
spi_slave->regs = bus->regs;
spi_slave->mode = mode;
spi_slave->periph_id = bus->periph_id;
if (bus->periph_id == PERIPH_ID_SPI1 ||
bus->periph_id == PERIPH_ID_SPI2)
spi_slave->fifo_size = 64;
else
spi_slave->fifo_size = 256;
spi_slave->freq = bus->frequency;
if (max_hz)
spi_slave->freq = min(max_hz, spi_slave->freq);
return &spi_slave->slave;
}
/**
* Free spi controller
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
*/
void spi_free_slave(struct spi_slave *slave)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
free(spi_slave);
}
/**
* Flush spi tx, rx fifos and reset the SPI controller
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
*/
static void spi_flush_fifo(struct spi_slave *slave)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
struct exynos_spi *regs = spi_slave->regs;
clrsetbits_le32(&regs->ch_cfg, SPI_CH_HS_EN, SPI_CH_RST);
clrbits_le32(&regs->ch_cfg, SPI_CH_RST);
setbits_le32(&regs->ch_cfg, SPI_TX_CH_ON | SPI_RX_CH_ON);
}
/**
* Initialize the spi base registers, set the required clock frequency and
* initialize the gpios
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
* @return zero on success else a negative value
*/
int spi_claim_bus(struct spi_slave *slave)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
struct exynos_spi *regs = spi_slave->regs;
u32 reg = 0;
int ret;
ret = set_spi_clk(spi_slave->periph_id,
spi_slave->freq);
if (ret < 0) {
debug("%s: Failed to setup spi clock\n", __func__);
return ret;
}
exynos_pinmux_config(spi_slave->periph_id, PINMUX_FLAG_NONE);
spi_flush_fifo(slave);
reg = readl(&regs->ch_cfg);
reg &= ~(SPI_CH_CPHA_B | SPI_CH_CPOL_L);
if (spi_slave->mode & SPI_CPHA)
reg |= SPI_CH_CPHA_B;
if (spi_slave->mode & SPI_CPOL)
reg |= SPI_CH_CPOL_L;
writel(reg, &regs->ch_cfg);
writel(SPI_FB_DELAY_180, &regs->fb_clk);
return 0;
}
/**
* Reset the spi H/W and flush the tx and rx fifos
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
*/
void spi_release_bus(struct spi_slave *slave)
{
spi_flush_fifo(slave);
}
static void spi_get_fifo_levels(struct exynos_spi *regs,
int *rx_lvl, int *tx_lvl)
{
uint32_t spi_sts = readl(&regs->spi_sts);
*rx_lvl = (spi_sts >> SPI_RX_LVL_OFFSET) & SPI_FIFO_LVL_MASK;
*tx_lvl = (spi_sts >> SPI_TX_LVL_OFFSET) & SPI_FIFO_LVL_MASK;
}
/**
* If there's something to transfer, do a software reset and set a
* transaction size.
*
* @param regs SPI peripheral registers
* @param count Number of bytes to transfer
*/
static void spi_request_bytes(struct exynos_spi *regs, int count)
{
assert(count && count < (1 << 16));
setbits_le32(&regs->ch_cfg, SPI_CH_RST);
clrbits_le32(&regs->ch_cfg, SPI_CH_RST);
writel(count | SPI_PACKET_CNT_EN, &regs->pkt_cnt);
}
static void spi_rx_tx(struct exynos_spi_slave *spi_slave, int todo,
void **dinp, void const **doutp)
{
struct exynos_spi *regs = spi_slave->regs;
uchar *rxp = *dinp;
const uchar *txp = *doutp;
int rx_lvl, tx_lvl;
uint out_bytes, in_bytes;
out_bytes = in_bytes = todo;
/*
* If there's something to send, do a software reset and set a
* transaction size.
*/
spi_request_bytes(regs, todo);
/*
* Bytes are transmitted/received in pairs. Wait to receive all the
* data because then transmission will be done as well.
*/
while (in_bytes) {
int temp;
/* Keep the fifos full/empty. */
spi_get_fifo_levels(regs, &rx_lvl, &tx_lvl);
if (tx_lvl < spi_slave->fifo_size && out_bytes) {
temp = txp ? *txp++ : 0xff;
writel(temp, &regs->tx_data);
out_bytes--;
}
if (rx_lvl > 0 && in_bytes) {
temp = readl(&regs->rx_data);
if (rxp)
*rxp++ = temp;
in_bytes--;
}
}
*dinp = rxp;
*doutp = txp;
}
/**
* Transfer and receive data
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
* @param bitlen No of bits to tranfer or receive
* @param dout Pointer to transfer buffer
* @param din Pointer to receive buffer
* @param flags Flags for transfer begin and end
* @return zero on success else a negative value
*/
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
int upto, todo;
int bytelen;
/* spi core configured to do 8 bit transfers */
if (bitlen % 8) {
debug("Non byte aligned SPI transfer.\n");
return -1;
}
/* Start the transaction, if necessary. */
if ((flags & SPI_XFER_BEGIN))
spi_cs_activate(slave);
/* Exynos SPI limits each transfer to 65535 bytes */
bytelen = bitlen / 8;
for (upto = 0; upto < bytelen; upto += todo) {
todo = min(bytelen - upto, (1 << 16) - 1);
spi_rx_tx(spi_slave, todo, &din, &dout);
}
/* Stop the transaction, if necessary. */
if ((flags & SPI_XFER_END))
spi_cs_deactivate(slave);
return 0;
}
/**
* Validates the bus and chip select numbers
*
* @param bus ID of the bus that the slave is attached to
* @param cs ID of the chip select connected to the slave
* @return one on success else zero
*/
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return spi_get_bus(bus) && cs == 0;
}
/**
* Activate the CS by driving it LOW
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
*/
void spi_cs_activate(struct spi_slave *slave)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
clrbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
debug("Activate CS, bus %d\n", spi_slave->slave.bus);
}
/**
* Deactivate the CS by driving it HIGH
*
* @param slave Pointer to spi_slave to which controller has to
* communicate with
*/
void spi_cs_deactivate(struct spi_slave *slave)
{
struct exynos_spi_slave *spi_slave = to_exynos_spi(slave);
setbits_le32(&spi_slave->regs->cs_reg, SPI_SLAVE_SIG_INACT);
debug("Deactivate CS, bus %d\n", spi_slave->slave.bus);
}
static inline struct exynos_spi *get_spi_base(int dev_index)
{
if (dev_index < 3)
return (struct exynos_spi *)samsung_get_base_spi() + dev_index;
else
return (struct exynos_spi *)samsung_get_base_spi_isp() +
(dev_index - 3);
}
/* Sadly there is no error return from this function */
void spi_init(void)
{
int i;
struct spi_bus *bus;
for (i = 0; i < EXYNOS5_SPI_NUM_CONTROLLERS; i++) {
bus = &spi_bus[i];
bus->regs = get_spi_base(i);
bus->periph_id = PERIPH_ID_SPI0 + i;
/* Although Exynos5 supports upto 50Mhz speed,
* we are setting it to 10Mhz for safe side
*/
bus->frequency = 10000000;
bus->inited = 1;
}
}
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