kernel-fxtec-pro1x/drivers/spi/dw_spi.c

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/*
* dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c)
*
* Copyright (c) 2009, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <linux/delay.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
#include <linux/slab.h>
#include <linux/spi/dw_spi.h>
#include <linux/spi/spi.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
#define START_STATE ((void *)0)
#define RUNNING_STATE ((void *)1)
#define DONE_STATE ((void *)2)
#define ERROR_STATE ((void *)-1)
#define QUEUE_RUNNING 0
#define QUEUE_STOPPED 1
#define MRST_SPI_DEASSERT 0
#define MRST_SPI_ASSERT 1
/* Slave spi_dev related */
struct chip_data {
u16 cr0;
u8 cs; /* chip select pin */
u8 n_bytes; /* current is a 1/2/4 byte op */
u8 tmode; /* TR/TO/RO/EEPROM */
u8 type; /* SPI/SSP/MicroWire */
u8 poll_mode; /* 1 means use poll mode */
u32 dma_width;
u32 rx_threshold;
u32 tx_threshold;
u8 enable_dma;
u8 bits_per_word;
u16 clk_div; /* baud rate divider */
u32 speed_hz; /* baud rate */
int (*write)(struct dw_spi *dws);
int (*read)(struct dw_spi *dws);
void (*cs_control)(u32 command);
};
#ifdef CONFIG_DEBUG_FS
static int spi_show_regs_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
#define SPI_REGS_BUFSIZE 1024
static ssize_t spi_show_regs(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct dw_spi *dws;
char *buf;
u32 len = 0;
ssize_t ret;
dws = file->private_data;
buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL);
if (!buf)
return 0;
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"MRST SPI0 registers:\n");
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"=================================\n");
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"SSIENR: \t0x%08x\n", dw_readl(dws, ssienr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"SER: \t\t0x%08x\n", dw_readl(dws, ser));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"SR: \t\t0x%08x\n", dw_readl(dws, sr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"IMR: \t\t0x%08x\n", dw_readl(dws, imr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"ISR: \t\t0x%08x\n", dw_readl(dws, isr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr));
len += snprintf(buf + len, SPI_REGS_BUFSIZE - len,
"=================================\n");
ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
return ret;
}
static const struct file_operations mrst_spi_regs_ops = {
.owner = THIS_MODULE,
.open = spi_show_regs_open,
.read = spi_show_regs,
};
static int mrst_spi_debugfs_init(struct dw_spi *dws)
{
dws->debugfs = debugfs_create_dir("mrst_spi", NULL);
if (!dws->debugfs)
return -ENOMEM;
debugfs_create_file("registers", S_IFREG | S_IRUGO,
dws->debugfs, (void *)dws, &mrst_spi_regs_ops);
return 0;
}
static void mrst_spi_debugfs_remove(struct dw_spi *dws)
{
if (dws->debugfs)
debugfs_remove_recursive(dws->debugfs);
}
#else
static inline int mrst_spi_debugfs_init(struct dw_spi *dws)
{
return 0;
}
static inline void mrst_spi_debugfs_remove(struct dw_spi *dws)
{
}
#endif /* CONFIG_DEBUG_FS */
static void wait_till_not_busy(struct dw_spi *dws)
{
unsigned long end = jiffies + 1 + usecs_to_jiffies(1000);
while (time_before(jiffies, end)) {
if (!(dw_readw(dws, sr) & SR_BUSY))
return;
}
dev_err(&dws->master->dev,
"DW SPI: Status keeps busy for 1000us after a read/write!\n");
}
static void flush(struct dw_spi *dws)
{
while (dw_readw(dws, sr) & SR_RF_NOT_EMPT)
dw_readw(dws, dr);
wait_till_not_busy(dws);
}
static int null_writer(struct dw_spi *dws)
{
u8 n_bytes = dws->n_bytes;
if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
|| (dws->tx == dws->tx_end))
return 0;
dw_writew(dws, dr, 0);
dws->tx += n_bytes;
wait_till_not_busy(dws);
return 1;
}
static int null_reader(struct dw_spi *dws)
{
u8 n_bytes = dws->n_bytes;
while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
&& (dws->rx < dws->rx_end)) {
dw_readw(dws, dr);
dws->rx += n_bytes;
}
wait_till_not_busy(dws);
return dws->rx == dws->rx_end;
}
static int u8_writer(struct dw_spi *dws)
{
if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
|| (dws->tx == dws->tx_end))
return 0;
dw_writew(dws, dr, *(u8 *)(dws->tx));
++dws->tx;
wait_till_not_busy(dws);
return 1;
}
static int u8_reader(struct dw_spi *dws)
{
while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
&& (dws->rx < dws->rx_end)) {
*(u8 *)(dws->rx) = dw_readw(dws, dr);
++dws->rx;
}
wait_till_not_busy(dws);
return dws->rx == dws->rx_end;
}
static int u16_writer(struct dw_spi *dws)
{
if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL)
|| (dws->tx == dws->tx_end))
return 0;
dw_writew(dws, dr, *(u16 *)(dws->tx));
dws->tx += 2;
wait_till_not_busy(dws);
return 1;
}
static int u16_reader(struct dw_spi *dws)
{
u16 temp;
while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT)
&& (dws->rx < dws->rx_end)) {
temp = dw_readw(dws, dr);
*(u16 *)(dws->rx) = temp;
dws->rx += 2;
}
wait_till_not_busy(dws);
return dws->rx == dws->rx_end;
}
static void *next_transfer(struct dw_spi *dws)
{
struct spi_message *msg = dws->cur_msg;
struct spi_transfer *trans = dws->cur_transfer;
/* Move to next transfer */
if (trans->transfer_list.next != &msg->transfers) {
dws->cur_transfer =
list_entry(trans->transfer_list.next,
struct spi_transfer,
transfer_list);
return RUNNING_STATE;
} else
return DONE_STATE;
}
/*
* Note: first step is the protocol driver prepares
* a dma-capable memory, and this func just need translate
* the virt addr to physical
*/
static int map_dma_buffers(struct dw_spi *dws)
{
if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited
|| !dws->cur_chip->enable_dma)
return 0;
if (dws->cur_transfer->tx_dma)
dws->tx_dma = dws->cur_transfer->tx_dma;
if (dws->cur_transfer->rx_dma)
dws->rx_dma = dws->cur_transfer->rx_dma;
return 1;
}
/* Caller already set message->status; dma and pio irqs are blocked */
static void giveback(struct dw_spi *dws)
{
struct spi_transfer *last_transfer;
unsigned long flags;
struct spi_message *msg;
spin_lock_irqsave(&dws->lock, flags);
msg = dws->cur_msg;
dws->cur_msg = NULL;
dws->cur_transfer = NULL;
dws->prev_chip = dws->cur_chip;
dws->cur_chip = NULL;
dws->dma_mapped = 0;
queue_work(dws->workqueue, &dws->pump_messages);
spin_unlock_irqrestore(&dws->lock, flags);
last_transfer = list_entry(msg->transfers.prev,
struct spi_transfer,
transfer_list);
if (!last_transfer->cs_change && dws->cs_control)
dws->cs_control(MRST_SPI_DEASSERT);
msg->state = NULL;
if (msg->complete)
msg->complete(msg->context);
}
static void int_error_stop(struct dw_spi *dws, const char *msg)
{
/* Stop and reset hw */
flush(dws);
spi_enable_chip(dws, 0);
dev_err(&dws->master->dev, "%s\n", msg);
dws->cur_msg->state = ERROR_STATE;
tasklet_schedule(&dws->pump_transfers);
}
static void transfer_complete(struct dw_spi *dws)
{
/* Update total byte transfered return count actual bytes read */
dws->cur_msg->actual_length += dws->len;
/* Move to next transfer */
dws->cur_msg->state = next_transfer(dws);
/* Handle end of message */
if (dws->cur_msg->state == DONE_STATE) {
dws->cur_msg->status = 0;
giveback(dws);
} else
tasklet_schedule(&dws->pump_transfers);
}
static irqreturn_t interrupt_transfer(struct dw_spi *dws)
{
u16 irq_status, irq_mask = 0x3f;
u32 int_level = dws->fifo_len / 2;
u32 left;
irq_status = dw_readw(dws, isr) & irq_mask;
/* Error handling */
if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) {
dw_readw(dws, txoicr);
dw_readw(dws, rxoicr);
dw_readw(dws, rxuicr);
int_error_stop(dws, "interrupt_transfer: fifo overrun");
return IRQ_HANDLED;
}
if (irq_status & SPI_INT_TXEI) {
spi_mask_intr(dws, SPI_INT_TXEI);
left = (dws->tx_end - dws->tx) / dws->n_bytes;
left = (left > int_level) ? int_level : left;
while (left--)
dws->write(dws);
dws->read(dws);
/* Re-enable the IRQ if there is still data left to tx */
if (dws->tx_end > dws->tx)
spi_umask_intr(dws, SPI_INT_TXEI);
else
transfer_complete(dws);
}
return IRQ_HANDLED;
}
static irqreturn_t dw_spi_irq(int irq, void *dev_id)
{
struct dw_spi *dws = dev_id;
u16 irq_status, irq_mask = 0x3f;
irq_status = dw_readw(dws, isr) & irq_mask;
if (!irq_status)
return IRQ_NONE;
if (!dws->cur_msg) {
spi_mask_intr(dws, SPI_INT_TXEI);
/* Never fail */
return IRQ_HANDLED;
}
return dws->transfer_handler(dws);
}
/* Must be called inside pump_transfers() */
static void poll_transfer(struct dw_spi *dws)
{
while (dws->write(dws))
dws->read(dws);
transfer_complete(dws);
}
static void dma_transfer(struct dw_spi *dws, int cs_change)
{
}
static void pump_transfers(unsigned long data)
{
struct dw_spi *dws = (struct dw_spi *)data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct spi_device *spi = NULL;
struct chip_data *chip = NULL;
u8 bits = 0;
u8 imask = 0;
u8 cs_change = 0;
u16 txint_level = 0;
u16 clk_div = 0;
u32 speed = 0;
u32 cr0 = 0;
/* Get current state information */
message = dws->cur_msg;
transfer = dws->cur_transfer;
chip = dws->cur_chip;
spi = message->spi;
if (unlikely(!chip->clk_div))
chip->clk_div = dws->max_freq / chip->speed_hz;
if (message->state == ERROR_STATE) {
message->status = -EIO;
goto early_exit;
}
/* Handle end of message */
if (message->state == DONE_STATE) {
message->status = 0;
goto early_exit;
}
/* Delay if requested at end of transfer*/
if (message->state == RUNNING_STATE) {
previous = list_entry(transfer->transfer_list.prev,
struct spi_transfer,
transfer_list);
if (previous->delay_usecs)
udelay(previous->delay_usecs);
}
dws->n_bytes = chip->n_bytes;
dws->dma_width = chip->dma_width;
dws->cs_control = chip->cs_control;
dws->rx_dma = transfer->rx_dma;
dws->tx_dma = transfer->tx_dma;
dws->tx = (void *)transfer->tx_buf;
dws->tx_end = dws->tx + transfer->len;
dws->rx = transfer->rx_buf;
dws->rx_end = dws->rx + transfer->len;
dws->write = dws->tx ? chip->write : null_writer;
dws->read = dws->rx ? chip->read : null_reader;
dws->cs_change = transfer->cs_change;
dws->len = dws->cur_transfer->len;
if (chip != dws->prev_chip)
cs_change = 1;
cr0 = chip->cr0;
/* Handle per transfer options for bpw and speed */
if (transfer->speed_hz) {
speed = chip->speed_hz;
if (transfer->speed_hz != speed) {
speed = transfer->speed_hz;
if (speed > dws->max_freq) {
printk(KERN_ERR "MRST SPI0: unsupported"
"freq: %dHz\n", speed);
message->status = -EIO;
goto early_exit;
}
/* clk_div doesn't support odd number */
clk_div = dws->max_freq / speed;
clk_div = (clk_div + 1) & 0xfffe;
chip->speed_hz = speed;
chip->clk_div = clk_div;
}
}
if (transfer->bits_per_word) {
bits = transfer->bits_per_word;
switch (bits) {
case 8:
dws->n_bytes = 1;
dws->dma_width = 1;
dws->read = (dws->read != null_reader) ?
u8_reader : null_reader;
dws->write = (dws->write != null_writer) ?
u8_writer : null_writer;
break;
case 16:
dws->n_bytes = 2;
dws->dma_width = 2;
dws->read = (dws->read != null_reader) ?
u16_reader : null_reader;
dws->write = (dws->write != null_writer) ?
u16_writer : null_writer;
break;
default:
printk(KERN_ERR "MRST SPI0: unsupported bits:"
"%db\n", bits);
message->status = -EIO;
goto early_exit;
}
cr0 = (bits - 1)
| (chip->type << SPI_FRF_OFFSET)
| (spi->mode << SPI_MODE_OFFSET)
| (chip->tmode << SPI_TMOD_OFFSET);
}
message->state = RUNNING_STATE;
/*
* Adjust transfer mode if necessary. Requires platform dependent
* chipselect mechanism.
*/
if (dws->cs_control) {
if (dws->rx && dws->tx)
chip->tmode = SPI_TMOD_TR;
else if (dws->rx)
chip->tmode = SPI_TMOD_RO;
else
chip->tmode = SPI_TMOD_TO;
cr0 &= ~SPI_TMOD_MASK;
cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
}
/* Check if current transfer is a DMA transaction */
dws->dma_mapped = map_dma_buffers(dws);
/*
* Interrupt mode
* we only need set the TXEI IRQ, as TX/RX always happen syncronizely
*/
if (!dws->dma_mapped && !chip->poll_mode) {
int templen = dws->len / dws->n_bytes;
txint_level = dws->fifo_len / 2;
txint_level = (templen > txint_level) ? txint_level : templen;
imask |= SPI_INT_TXEI;
dws->transfer_handler = interrupt_transfer;
}
/*
* Reprogram registers only if
* 1. chip select changes
* 2. clk_div is changed
* 3. control value changes
*/
if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) {
spi_enable_chip(dws, 0);
if (dw_readw(dws, ctrl0) != cr0)
dw_writew(dws, ctrl0, cr0);
spi_set_clk(dws, clk_div ? clk_div : chip->clk_div);
spi_chip_sel(dws, spi->chip_select);
/* Set the interrupt mask, for poll mode just diable all int */
spi_mask_intr(dws, 0xff);
if (imask)
spi_umask_intr(dws, imask);
if (txint_level)
dw_writew(dws, txfltr, txint_level);
spi_enable_chip(dws, 1);
if (cs_change)
dws->prev_chip = chip;
}
if (dws->dma_mapped)
dma_transfer(dws, cs_change);
if (chip->poll_mode)
poll_transfer(dws);
return;
early_exit:
giveback(dws);
return;
}
static void pump_messages(struct work_struct *work)
{
struct dw_spi *dws =
container_of(work, struct dw_spi, pump_messages);
unsigned long flags;
/* Lock queue and check for queue work */
spin_lock_irqsave(&dws->lock, flags);
if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) {
dws->busy = 0;
spin_unlock_irqrestore(&dws->lock, flags);
return;
}
/* Make sure we are not already running a message */
if (dws->cur_msg) {
spin_unlock_irqrestore(&dws->lock, flags);
return;
}
/* Extract head of queue */
dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue);
list_del_init(&dws->cur_msg->queue);
/* Initial message state*/
dws->cur_msg->state = START_STATE;
dws->cur_transfer = list_entry(dws->cur_msg->transfers.next,
struct spi_transfer,
transfer_list);
dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi);
/* Mark as busy and launch transfers */
tasklet_schedule(&dws->pump_transfers);
dws->busy = 1;
spin_unlock_irqrestore(&dws->lock, flags);
}
/* spi_device use this to queue in their spi_msg */
static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg)
{
struct dw_spi *dws = spi_master_get_devdata(spi->master);
unsigned long flags;
spin_lock_irqsave(&dws->lock, flags);
if (dws->run == QUEUE_STOPPED) {
spin_unlock_irqrestore(&dws->lock, flags);
return -ESHUTDOWN;
}
msg->actual_length = 0;
msg->status = -EINPROGRESS;
msg->state = START_STATE;
list_add_tail(&msg->queue, &dws->queue);
if (dws->run == QUEUE_RUNNING && !dws->busy) {
if (dws->cur_transfer || dws->cur_msg)
queue_work(dws->workqueue,
&dws->pump_messages);
else {
/* If no other data transaction in air, just go */
spin_unlock_irqrestore(&dws->lock, flags);
pump_messages(&dws->pump_messages);
return 0;
}
}
spin_unlock_irqrestore(&dws->lock, flags);
return 0;
}
/* This may be called twice for each spi dev */
static int dw_spi_setup(struct spi_device *spi)
{
struct dw_spi_chip *chip_info = NULL;
struct chip_data *chip;
if (spi->bits_per_word != 8 && spi->bits_per_word != 16)
return -EINVAL;
/* Only alloc on first setup */
chip = spi_get_ctldata(spi);
if (!chip) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
if (!chip)
return -ENOMEM;
}
/*
* Protocol drivers may change the chip settings, so...
* if chip_info exists, use it
*/
chip_info = spi->controller_data;
/* chip_info doesn't always exist */
if (chip_info) {
if (chip_info->cs_control)
chip->cs_control = chip_info->cs_control;
chip->poll_mode = chip_info->poll_mode;
chip->type = chip_info->type;
chip->rx_threshold = 0;
chip->tx_threshold = 0;
chip->enable_dma = chip_info->enable_dma;
}
if (spi->bits_per_word <= 8) {
chip->n_bytes = 1;
chip->dma_width = 1;
chip->read = u8_reader;
chip->write = u8_writer;
} else if (spi->bits_per_word <= 16) {
chip->n_bytes = 2;
chip->dma_width = 2;
chip->read = u16_reader;
chip->write = u16_writer;
} else {
/* Never take >16b case for MRST SPIC */
dev_err(&spi->dev, "invalid wordsize\n");
return -EINVAL;
}
chip->bits_per_word = spi->bits_per_word;
if (!spi->max_speed_hz) {
dev_err(&spi->dev, "No max speed HZ parameter\n");
return -EINVAL;
}
chip->speed_hz = spi->max_speed_hz;
chip->tmode = 0; /* Tx & Rx */
/* Default SPI mode is SCPOL = 0, SCPH = 0 */
chip->cr0 = (chip->bits_per_word - 1)
| (chip->type << SPI_FRF_OFFSET)
| (spi->mode << SPI_MODE_OFFSET)
| (chip->tmode << SPI_TMOD_OFFSET);
spi_set_ctldata(spi, chip);
return 0;
}
static void dw_spi_cleanup(struct spi_device *spi)
{
struct chip_data *chip = spi_get_ctldata(spi);
kfree(chip);
}
static int __devinit init_queue(struct dw_spi *dws)
{
INIT_LIST_HEAD(&dws->queue);
spin_lock_init(&dws->lock);
dws->run = QUEUE_STOPPED;
dws->busy = 0;
tasklet_init(&dws->pump_transfers,
pump_transfers, (unsigned long)dws);
INIT_WORK(&dws->pump_messages, pump_messages);
dws->workqueue = create_singlethread_workqueue(
dev_name(dws->master->dev.parent));
if (dws->workqueue == NULL)
return -EBUSY;
return 0;
}
static int start_queue(struct dw_spi *dws)
{
unsigned long flags;
spin_lock_irqsave(&dws->lock, flags);
if (dws->run == QUEUE_RUNNING || dws->busy) {
spin_unlock_irqrestore(&dws->lock, flags);
return -EBUSY;
}
dws->run = QUEUE_RUNNING;
dws->cur_msg = NULL;
dws->cur_transfer = NULL;
dws->cur_chip = NULL;
dws->prev_chip = NULL;
spin_unlock_irqrestore(&dws->lock, flags);
queue_work(dws->workqueue, &dws->pump_messages);
return 0;
}
static int stop_queue(struct dw_spi *dws)
{
unsigned long flags;
unsigned limit = 50;
int status = 0;
spin_lock_irqsave(&dws->lock, flags);
dws->run = QUEUE_STOPPED;
while (!list_empty(&dws->queue) && dws->busy && limit--) {
spin_unlock_irqrestore(&dws->lock, flags);
msleep(10);
spin_lock_irqsave(&dws->lock, flags);
}
if (!list_empty(&dws->queue) || dws->busy)
status = -EBUSY;
spin_unlock_irqrestore(&dws->lock, flags);
return status;
}
static int destroy_queue(struct dw_spi *dws)
{
int status;
status = stop_queue(dws);
if (status != 0)
return status;
destroy_workqueue(dws->workqueue);
return 0;
}
/* Restart the controller, disable all interrupts, clean rx fifo */
static void spi_hw_init(struct dw_spi *dws)
{
spi_enable_chip(dws, 0);
spi_mask_intr(dws, 0xff);
spi_enable_chip(dws, 1);
flush(dws);
/*
* Try to detect the FIFO depth if not set by interface driver,
* the depth could be from 2 to 256 from HW spec
*/
if (!dws->fifo_len) {
u32 fifo;
for (fifo = 2; fifo <= 257; fifo++) {
dw_writew(dws, txfltr, fifo);
if (fifo != dw_readw(dws, txfltr))
break;
}
dws->fifo_len = (fifo == 257) ? 0 : fifo;
dw_writew(dws, txfltr, 0);
}
}
int __devinit dw_spi_add_host(struct dw_spi *dws)
{
struct spi_master *master;
int ret;
BUG_ON(dws == NULL);
master = spi_alloc_master(dws->parent_dev, 0);
if (!master) {
ret = -ENOMEM;
goto exit;
}
dws->master = master;
dws->type = SSI_MOTO_SPI;
dws->prev_chip = NULL;
dws->dma_inited = 0;
dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60);
ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED,
"dw_spi", dws);
if (ret < 0) {
dev_err(&master->dev, "can not get IRQ\n");
goto err_free_master;
}
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->bus_num = dws->bus_num;
master->num_chipselect = dws->num_cs;
master->cleanup = dw_spi_cleanup;
master->setup = dw_spi_setup;
master->transfer = dw_spi_transfer;
dws->dma_inited = 0;
/* Basic HW init */
spi_hw_init(dws);
/* Initial and start queue */
ret = init_queue(dws);
if (ret) {
dev_err(&master->dev, "problem initializing queue\n");
goto err_diable_hw;
}
ret = start_queue(dws);
if (ret) {
dev_err(&master->dev, "problem starting queue\n");
goto err_diable_hw;
}
spi_master_set_devdata(master, dws);
ret = spi_register_master(master);
if (ret) {
dev_err(&master->dev, "problem registering spi master\n");
goto err_queue_alloc;
}
mrst_spi_debugfs_init(dws);
return 0;
err_queue_alloc:
destroy_queue(dws);
err_diable_hw:
spi_enable_chip(dws, 0);
free_irq(dws->irq, dws);
err_free_master:
spi_master_put(master);
exit:
return ret;
}
EXPORT_SYMBOL(dw_spi_add_host);
void __devexit dw_spi_remove_host(struct dw_spi *dws)
{
int status = 0;
if (!dws)
return;
mrst_spi_debugfs_remove(dws);
/* Remove the queue */
status = destroy_queue(dws);
if (status != 0)
dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not "
"complete, message memory not freed\n");
spi_enable_chip(dws, 0);
/* Disable clk */
spi_set_clk(dws, 0);
free_irq(dws->irq, dws);
/* Disconnect from the SPI framework */
spi_unregister_master(dws->master);
}
EXPORT_SYMBOL(dw_spi_remove_host);
int dw_spi_suspend_host(struct dw_spi *dws)
{
int ret = 0;
ret = stop_queue(dws);
if (ret)
return ret;
spi_enable_chip(dws, 0);
spi_set_clk(dws, 0);
return ret;
}
EXPORT_SYMBOL(dw_spi_suspend_host);
int dw_spi_resume_host(struct dw_spi *dws)
{
int ret;
spi_hw_init(dws);
ret = start_queue(dws);
if (ret)
dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret);
return ret;
}
EXPORT_SYMBOL(dw_spi_resume_host);
MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>");
MODULE_DESCRIPTION("Driver for DesignWare SPI controller core");
MODULE_LICENSE("GPL v2");