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linux-next/drivers/spi/spi-fsl-espi.c

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spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
/*
* Freescale eSPI controller driver.
*
* Copyright 2010 Freescale Semiconductor, Inc.
*
* 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.
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/spi/spi.h>
#include <linux/platform_device.h>
#include <linux/fsl_devices.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_spi.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <sysdev/fsl_soc.h>
spi: reorganize drivers Sort the SPI makefile and enforce the naming convention spi_*.c for spi drivers. This change also rolls the contents of atmel_spi.h into the .c file since there is only one user of that particular include file. v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be be the predominant pattern for subsystem prefixes. - Clean up filenames in Kconfig and header comment blocks Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Linus Walleij <linus.walleij@linaro.org>
2011-06-06 15:16:30 +08:00
#include "spi-fsl-lib.h"
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
/* eSPI Controller registers */
struct fsl_espi_reg {
__be32 mode; /* 0x000 - eSPI mode register */
__be32 event; /* 0x004 - eSPI event register */
__be32 mask; /* 0x008 - eSPI mask register */
__be32 command; /* 0x00c - eSPI command register */
__be32 transmit; /* 0x010 - eSPI transmit FIFO access register*/
__be32 receive; /* 0x014 - eSPI receive FIFO access register*/
u8 res[8]; /* 0x018 - 0x01c reserved */
__be32 csmode[4]; /* 0x020 - 0x02c eSPI cs mode register */
};
struct fsl_espi_transfer {
const void *tx_buf;
void *rx_buf;
unsigned len;
unsigned n_tx;
unsigned n_rx;
unsigned actual_length;
int status;
};
/* eSPI Controller mode register definitions */
#define SPMODE_ENABLE (1 << 31)
#define SPMODE_LOOP (1 << 30)
#define SPMODE_TXTHR(x) ((x) << 8)
#define SPMODE_RXTHR(x) ((x) << 0)
/* eSPI Controller CS mode register definitions */
#define CSMODE_CI_INACTIVEHIGH (1 << 31)
#define CSMODE_CP_BEGIN_EDGECLK (1 << 30)
#define CSMODE_REV (1 << 29)
#define CSMODE_DIV16 (1 << 28)
#define CSMODE_PM(x) ((x) << 24)
#define CSMODE_POL_1 (1 << 20)
#define CSMODE_LEN(x) ((x) << 16)
#define CSMODE_BEF(x) ((x) << 12)
#define CSMODE_AFT(x) ((x) << 8)
#define CSMODE_CG(x) ((x) << 3)
/* Default mode/csmode for eSPI controller */
#define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
#define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
| CSMODE_AFT(0) | CSMODE_CG(1))
/* SPIE register values */
#define SPIE_NE 0x00000200 /* Not empty */
#define SPIE_NF 0x00000100 /* Not full */
/* SPIM register values */
#define SPIM_NE 0x00000200 /* Not empty */
#define SPIM_NF 0x00000100 /* Not full */
#define SPIE_RXCNT(reg) ((reg >> 24) & 0x3F)
#define SPIE_TXCNT(reg) ((reg >> 16) & 0x3F)
/* SPCOM register values */
#define SPCOM_CS(x) ((x) << 30)
#define SPCOM_TRANLEN(x) ((x) << 0)
#define SPCOM_TRANLEN_MAX 0xFFFF /* Max transaction length */
static void fsl_espi_change_mode(struct spi_device *spi)
{
struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct spi_mpc8xxx_cs *cs = spi->controller_state;
struct fsl_espi_reg *reg_base = mspi->reg_base;
__be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
__be32 __iomem *espi_mode = &reg_base->mode;
u32 tmp;
unsigned long flags;
/* Turn off IRQs locally to minimize time that SPI is disabled. */
local_irq_save(flags);
/* Turn off SPI unit prior changing mode */
tmp = mpc8xxx_spi_read_reg(espi_mode);
mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
mpc8xxx_spi_write_reg(mode, cs->hw_mode);
mpc8xxx_spi_write_reg(espi_mode, tmp);
local_irq_restore(flags);
}
static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
{
u32 data;
u16 data_h;
u16 data_l;
const u32 *tx = mpc8xxx_spi->tx;
if (!tx)
return 0;
data = *tx++ << mpc8xxx_spi->tx_shift;
data_l = data & 0xffff;
data_h = (data >> 16) & 0xffff;
swab16s(&data_l);
swab16s(&data_h);
data = data_h | data_l;
mpc8xxx_spi->tx = tx;
return data;
}
static int fsl_espi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
int bits_per_word = 0;
u8 pm;
u32 hz = 0;
struct spi_mpc8xxx_cs *cs = spi->controller_state;
if (t) {
bits_per_word = t->bits_per_word;
hz = t->speed_hz;
}
/* spi_transfer level calls that work per-word */
if (!bits_per_word)
bits_per_word = spi->bits_per_word;
/* Make sure its a bit width we support [4..16] */
if ((bits_per_word < 4) || (bits_per_word > 16))
return -EINVAL;
if (!hz)
hz = spi->max_speed_hz;
cs->rx_shift = 0;
cs->tx_shift = 0;
cs->get_rx = mpc8xxx_spi_rx_buf_u32;
cs->get_tx = mpc8xxx_spi_tx_buf_u32;
if (bits_per_word <= 8) {
cs->rx_shift = 8 - bits_per_word;
} else if (bits_per_word <= 16) {
cs->rx_shift = 16 - bits_per_word;
if (spi->mode & SPI_LSB_FIRST)
cs->get_tx = fsl_espi_tx_buf_lsb;
} else {
return -EINVAL;
}
mpc8xxx_spi->rx_shift = cs->rx_shift;
mpc8xxx_spi->tx_shift = cs->tx_shift;
mpc8xxx_spi->get_rx = cs->get_rx;
mpc8xxx_spi->get_tx = cs->get_tx;
bits_per_word = bits_per_word - 1;
/* mask out bits we are going to set */
cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
cs->hw_mode |= CSMODE_LEN(bits_per_word);
if ((mpc8xxx_spi->spibrg / hz) > 64) {
cs->hw_mode |= CSMODE_DIV16;
pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
"Will use %d Hz instead.\n", dev_name(&spi->dev),
hz, mpc8xxx_spi->spibrg / 1024);
if (pm > 16)
pm = 16;
} else {
pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
}
if (pm)
pm--;
cs->hw_mode |= CSMODE_PM(pm);
fsl_espi_change_mode(spi);
return 0;
}
static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
unsigned int len)
{
u32 word;
struct fsl_espi_reg *reg_base = mspi->reg_base;
mspi->count = len;
/* enable rx ints */
mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
/* transmit word */
word = mspi->get_tx(mspi);
mpc8xxx_spi_write_reg(&reg_base->transmit, word);
return 0;
}
static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
unsigned int len = t->len;
u8 bits_per_word;
int ret;
bits_per_word = spi->bits_per_word;
if (t->bits_per_word)
bits_per_word = t->bits_per_word;
mpc8xxx_spi->len = t->len;
len = roundup(len, 4) / 4;
mpc8xxx_spi->tx = t->tx_buf;
mpc8xxx_spi->rx = t->rx_buf;
INIT_COMPLETION(mpc8xxx_spi->done);
/* Set SPCOM[CS] and SPCOM[TRANLEN] field */
if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
" beyond the SPCOM[TRANLEN] field\n", t->len);
return -EINVAL;
}
mpc8xxx_spi_write_reg(&reg_base->command,
(SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
if (ret)
return ret;
wait_for_completion(&mpc8xxx_spi->done);
/* disable rx ints */
mpc8xxx_spi_write_reg(&reg_base->mask, 0);
return mpc8xxx_spi->count;
}
spi/fsl_espi: fix wrong setting of the address in the command buffer Or else we can't operate on the right address when the trans length is greater than 65535. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:27:02 +08:00
static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
{
spi/fsl_espi: fix wrong setting of the address in the command buffer Or else we can't operate on the right address when the trans length is greater than 65535. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:27:02 +08:00
if (cmd) {
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
cmd[1] = (u8)(addr >> 16);
cmd[2] = (u8)(addr >> 8);
cmd[3] = (u8)(addr >> 0);
}
}
spi/fsl_espi: fix wrong setting of the address in the command buffer Or else we can't operate on the right address when the trans length is greater than 65535. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:27:02 +08:00
static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
{
spi/fsl_espi: fix wrong setting of the address in the command buffer Or else we can't operate on the right address when the trans length is greater than 65535. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:27:02 +08:00
if (cmd)
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
return 0;
}
static void fsl_espi_do_trans(struct spi_message *m,
struct fsl_espi_transfer *tr)
{
struct spi_device *spi = m->spi;
struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct fsl_espi_transfer *espi_trans = tr;
struct spi_message message;
struct spi_transfer *t, *first, trans;
int status = 0;
spi_message_init(&message);
memset(&trans, 0, sizeof(trans));
first = list_first_entry(&m->transfers, struct spi_transfer,
transfer_list);
list_for_each_entry(t, &m->transfers, transfer_list) {
if ((first->bits_per_word != t->bits_per_word) ||
(first->speed_hz != t->speed_hz)) {
espi_trans->status = -EINVAL;
dev_err(mspi->dev, "bits_per_word/speed_hz should be"
" same for the same SPI transfer\n");
return;
}
trans.speed_hz = t->speed_hz;
trans.bits_per_word = t->bits_per_word;
trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
}
trans.len = espi_trans->len;
trans.tx_buf = espi_trans->tx_buf;
trans.rx_buf = espi_trans->rx_buf;
spi_message_add_tail(&trans, &message);
list_for_each_entry(t, &message.transfers, transfer_list) {
if (t->bits_per_word || t->speed_hz) {
status = -EINVAL;
status = fsl_espi_setup_transfer(spi, t);
if (status < 0)
break;
}
if (t->len)
status = fsl_espi_bufs(spi, t);
if (status) {
status = -EMSGSIZE;
break;
}
if (t->delay_usecs)
udelay(t->delay_usecs);
}
espi_trans->status = status;
fsl_espi_setup_transfer(spi, NULL);
}
static void fsl_espi_cmd_trans(struct spi_message *m,
struct fsl_espi_transfer *trans, u8 *rx_buff)
{
struct spi_transfer *t;
u8 *local_buf;
int i = 0;
struct fsl_espi_transfer *espi_trans = trans;
local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
if (!local_buf) {
espi_trans->status = -ENOMEM;
return;
}
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf) {
memcpy(local_buf + i, t->tx_buf, t->len);
i += t->len;
}
}
espi_trans->tx_buf = local_buf;
espi_trans->rx_buf = local_buf + espi_trans->n_tx;
fsl_espi_do_trans(m, espi_trans);
espi_trans->actual_length = espi_trans->len;
kfree(local_buf);
}
static void fsl_espi_rw_trans(struct spi_message *m,
struct fsl_espi_transfer *trans, u8 *rx_buff)
{
struct fsl_espi_transfer *espi_trans = trans;
unsigned int n_tx = espi_trans->n_tx;
unsigned int n_rx = espi_trans->n_rx;
struct spi_transfer *t;
u8 *local_buf;
u8 *rx_buf = rx_buff;
unsigned int trans_len;
unsigned int addr;
int i, pos, loop;
local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
if (!local_buf) {
espi_trans->status = -ENOMEM;
return;
}
for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
trans_len = n_rx - pos;
if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
trans_len = SPCOM_TRANLEN_MAX - n_tx;
i = 0;
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf) {
memcpy(local_buf + i, t->tx_buf, t->len);
i += t->len;
}
}
spi/fsl_espi: fix wrong setting of the address in the command buffer Or else we can't operate on the right address when the trans length is greater than 65535. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:27:02 +08:00
if (pos > 0) {
addr = fsl_espi_cmd2addr(local_buf);
addr += pos;
fsl_espi_addr2cmd(addr, local_buf);
}
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
espi_trans->n_tx = n_tx;
espi_trans->n_rx = trans_len;
espi_trans->len = trans_len + n_tx;
espi_trans->tx_buf = local_buf;
espi_trans->rx_buf = local_buf + n_tx;
fsl_espi_do_trans(m, espi_trans);
memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
if (loop > 0)
espi_trans->actual_length += espi_trans->len - n_tx;
else
espi_trans->actual_length += espi_trans->len;
}
kfree(local_buf);
}
static void fsl_espi_do_one_msg(struct spi_message *m)
{
struct spi_transfer *t;
u8 *rx_buf = NULL;
unsigned int n_tx = 0;
unsigned int n_rx = 0;
struct fsl_espi_transfer espi_trans;
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf)
n_tx += t->len;
if (t->rx_buf) {
n_rx += t->len;
rx_buf = t->rx_buf;
}
}
espi_trans.n_tx = n_tx;
espi_trans.n_rx = n_rx;
espi_trans.len = n_tx + n_rx;
espi_trans.actual_length = 0;
espi_trans.status = 0;
if (!rx_buf)
fsl_espi_cmd_trans(m, &espi_trans, NULL);
else
fsl_espi_rw_trans(m, &espi_trans, rx_buf);
m->actual_length = espi_trans.actual_length;
m->status = espi_trans.status;
m->complete(m->context);
}
static int fsl_espi_setup(struct spi_device *spi)
{
struct mpc8xxx_spi *mpc8xxx_spi;
struct fsl_espi_reg *reg_base;
int retval;
u32 hw_mode;
u32 loop_mode;
struct spi_mpc8xxx_cs *cs = spi->controller_state;
if (!spi->max_speed_hz)
return -EINVAL;
if (!cs) {
cs = kzalloc(sizeof *cs, GFP_KERNEL);
if (!cs)
return -ENOMEM;
spi->controller_state = cs;
}
mpc8xxx_spi = spi_master_get_devdata(spi->master);
reg_base = mpc8xxx_spi->reg_base;
Fix common misspellings Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 09:57:33 +08:00
hw_mode = cs->hw_mode; /* Save original settings */
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
cs->hw_mode = mpc8xxx_spi_read_reg(
&reg_base->csmode[spi->chip_select]);
/* mask out bits we are going to set */
cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
| CSMODE_REV);
if (spi->mode & SPI_CPHA)
cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
if (spi->mode & SPI_CPOL)
cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
if (!(spi->mode & SPI_LSB_FIRST))
cs->hw_mode |= CSMODE_REV;
/* Handle the loop mode */
loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
loop_mode &= ~SPMODE_LOOP;
if (spi->mode & SPI_LOOP)
loop_mode |= SPMODE_LOOP;
mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
retval = fsl_espi_setup_transfer(spi, NULL);
if (retval < 0) {
cs->hw_mode = hw_mode; /* Restore settings */
return retval;
}
return 0;
}
void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
{
struct fsl_espi_reg *reg_base = mspi->reg_base;
/* We need handle RX first */
if (events & SPIE_NE) {
spi/fsl_espi: change the read behaviour of the SPIRF The user must read N bytes of SPIRF (1 <= N <= 4) that do not exceed the amount of data in the receive FIFO, so read the SPIRF byte by byte when the data in receive FIFO is less than 4 bytes. On Simics, when read N bytes that exceed the amount of data in receive FIFO, we can't read the data out, that is we can't clear the rx FIFO, then the CPU will loop on the espi rx interrupt. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:26:07 +08:00
u32 rx_data, tmp;
u8 rx_data_8;
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
/* Spin until RX is done */
while (SPIE_RXCNT(events) < min(4, mspi->len)) {
cpu_relax();
events = mpc8xxx_spi_read_reg(&reg_base->event);
}
spi/fsl_espi: change the read behaviour of the SPIRF The user must read N bytes of SPIRF (1 <= N <= 4) that do not exceed the amount of data in the receive FIFO, so read the SPIRF byte by byte when the data in receive FIFO is less than 4 bytes. On Simics, when read N bytes that exceed the amount of data in receive FIFO, we can't read the data out, that is we can't clear the rx FIFO, then the CPU will loop on the espi rx interrupt. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-21 09:26:07 +08:00
if (mspi->len >= 4) {
rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
} else {
tmp = mspi->len;
rx_data = 0;
while (tmp--) {
rx_data_8 = in_8((u8 *)&reg_base->receive);
rx_data |= (rx_data_8 << (tmp * 8));
}
rx_data <<= (4 - mspi->len) * 8;
}
mspi->len -= 4;
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
if (mspi->rx)
mspi->get_rx(rx_data, mspi);
}
if (!(events & SPIE_NF)) {
int ret;
/* spin until TX is done */
ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
&reg_base->event)) & SPIE_NF) == 0, 1000, 0);
if (!ret) {
dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
return;
}
}
/* Clear the events */
mpc8xxx_spi_write_reg(&reg_base->event, events);
mspi->count -= 1;
if (mspi->count) {
u32 word = mspi->get_tx(mspi);
mpc8xxx_spi_write_reg(&reg_base->transmit, word);
} else {
complete(&mspi->done);
}
}
static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
{
struct mpc8xxx_spi *mspi = context_data;
struct fsl_espi_reg *reg_base = mspi->reg_base;
irqreturn_t ret = IRQ_NONE;
u32 events;
/* Get interrupt events(tx/rx) */
events = mpc8xxx_spi_read_reg(&reg_base->event);
if (events)
ret = IRQ_HANDLED;
dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
fsl_espi_cpu_irq(mspi, events);
return ret;
}
static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
{
iounmap(mspi->reg_base);
}
static struct spi_master * __devinit fsl_espi_probe(struct device *dev,
struct resource *mem, unsigned int irq)
{
struct fsl_spi_platform_data *pdata = dev->platform_data;
struct spi_master *master;
struct mpc8xxx_spi *mpc8xxx_spi;
struct fsl_espi_reg *reg_base;
u32 regval;
int i, ret = 0;
master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
if (!master) {
ret = -ENOMEM;
goto err;
}
dev_set_drvdata(dev, master);
ret = mpc8xxx_spi_probe(dev, mem, irq);
if (ret)
goto err_probe;
master->setup = fsl_espi_setup;
mpc8xxx_spi = spi_master_get_devdata(master);
mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
mpc8xxx_spi->spi_remove = fsl_espi_remove;
mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
if (!mpc8xxx_spi->reg_base) {
ret = -ENOMEM;
goto err_probe;
}
reg_base = mpc8xxx_spi->reg_base;
/* Register for SPI Interrupt */
ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
0, "fsl_espi", mpc8xxx_spi);
if (ret)
goto free_irq;
if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
mpc8xxx_spi->rx_shift = 16;
mpc8xxx_spi->tx_shift = 24;
}
/* SPI controller initializations */
mpc8xxx_spi_write_reg(&reg_base->mode, 0);
mpc8xxx_spi_write_reg(&reg_base->mask, 0);
mpc8xxx_spi_write_reg(&reg_base->command, 0);
mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
/* Init eSPI CS mode register */
for (i = 0; i < pdata->max_chipselect; i++)
mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
/* Enable SPI interface */
regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
mpc8xxx_spi_write_reg(&reg_base->mode, regval);
ret = spi_register_master(master);
if (ret < 0)
goto unreg_master;
dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
return master;
unreg_master:
free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
free_irq:
iounmap(mpc8xxx_spi->reg_base);
err_probe:
spi_master_put(master);
err:
return ERR_PTR(ret);
}
static int of_fsl_espi_get_chipselects(struct device *dev)
{
struct device_node *np = dev->of_node;
struct fsl_spi_platform_data *pdata = dev->platform_data;
const u32 *prop;
int len;
prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
if (!prop || len < sizeof(*prop)) {
dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
return -EINVAL;
}
pdata->max_chipselect = *prop;
pdata->cs_control = NULL;
return 0;
}
dt/spi: Eliminate users of of_platform_{,un}register_driver Get rid of users of of_platform_driver in drivers/spi. The of_platform_{,un}register_driver functions are going away, so the users need to be converted to using the platform_bus_type directly. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-02-23 12:02:43 +08:00
static int __devinit of_fsl_espi_probe(struct platform_device *ofdev)
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
{
struct device *dev = &ofdev->dev;
struct device_node *np = ofdev->dev.of_node;
struct spi_master *master;
struct resource mem;
struct resource irq;
int ret = -ENOMEM;
dt/spi: Eliminate users of of_platform_{,un}register_driver Get rid of users of of_platform_driver in drivers/spi. The of_platform_{,un}register_driver functions are going away, so the users need to be converted to using the platform_bus_type directly. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-02-23 12:02:43 +08:00
ret = of_mpc8xxx_spi_probe(ofdev);
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
if (ret)
return ret;
ret = of_fsl_espi_get_chipselects(dev);
if (ret)
goto err;
ret = of_address_to_resource(np, 0, &mem);
if (ret)
goto err;
ret = of_irq_to_resource(np, 0, &irq);
if (!ret) {
ret = -EINVAL;
goto err;
}
master = fsl_espi_probe(dev, &mem, irq.start);
if (IS_ERR(master)) {
ret = PTR_ERR(master);
goto err;
}
return 0;
err:
return ret;
}
static int __devexit of_fsl_espi_remove(struct platform_device *dev)
{
return mpc8xxx_spi_remove(&dev->dev);
}
static const struct of_device_id of_fsl_espi_match[] = {
{ .compatible = "fsl,mpc8536-espi" },
{}
};
MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
dt/spi: Eliminate users of of_platform_{,un}register_driver Get rid of users of of_platform_driver in drivers/spi. The of_platform_{,un}register_driver functions are going away, so the users need to be converted to using the platform_bus_type directly. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-02-23 12:02:43 +08:00
static struct platform_driver fsl_espi_driver = {
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
.driver = {
.name = "fsl_espi",
.owner = THIS_MODULE,
.of_match_table = of_fsl_espi_match,
},
.probe = of_fsl_espi_probe,
.remove = __devexit_p(of_fsl_espi_remove),
};
drivercore: Add helper macro for platform_driver boilerplate For simple modules that contain a single platform_driver without any additional setup code then ends up being a block of duplicated boilerplate. This patch adds a new macro, module_platform_driver(), which replaces the module_init()/module_exit() registrations with template functions. Signed-off-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Reviewed-by: Magnus Damm <magnus.damm@gmail.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
2011-10-06 01:29:49 +08:00
module_platform_driver(fsl_espi_driver);
spi/fsl_spi: add eSPI controller support Add eSPI controller support based on the library code spi_fsl_lib.c. The eSPI controller is newer controller 85xx/Pxxx devices supported. There're some differences comparing to the SPI controller: 1. Has different register map and different bit definition So leave the code operated the register to the driver code, not the common code. 2. Support 4 dedicated chip selects The software can't controll the chip selects directly, The SPCOM[CS] field is used to select which chip selects is used, and the SPCOM[TRANLEN] field is set to tell the controller how long the CS signal need to be asserted. So the driver doesn't need the chipselect related function when transfering data, just set corresponding register fields to controll the chipseclect. 3. Different Transmit/Receive FIFO access register behavior For SPI controller, the Tx/Rx FIFO access register can hold only one character regardless of the character length, but for eSPI controller, the register can hold 4 or 2 characters according to the character lengths. Access the Tx/Rx FIFO access register of the eSPI controller will shift out/in 4/2 characters one time. For SPI subsystem, the command and data are put into different transfers, so we need to combine all the transfers to one transfer in order to pass the transfer to eSPI controller. 4. The max transaction length limitation The max transaction length one time is limitted by the SPCOM[TRANSLEN] field which is 0xFFFF. When used mkfs.ext2 command to create ext2 filesystem on the flash, the read length will exceed the max value of the SPCOM[TRANSLEN] field. Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 18:18:32 +08:00
MODULE_AUTHOR("Mingkai Hu");
MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
MODULE_LICENSE("GPL");
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