Skip to content

Commit

Permalink
spi: dw: move to SPI core message handling
Browse files Browse the repository at this point in the history 
This patch removes a lot of duplicate code since SPI core provides a nice
message handling.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
  • Loading branch information
Andy Shevchenko authored and Mark Brown committed Mar 6, 2015
1 parent 3e00803 commit c22c62d
Show file tree
Hide file tree
Showing 3 changed files with 49 additions and 164 deletions.
4 changes: 2 additions & 2 deletions drivers/spi/spi-dw-mid.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -110,7 +110,7 @@ static void dw_spi_dma_tx_done(void *arg)

if (test_and_clear_bit(TX_BUSY, &dws->dma_chan_busy) & BIT(RX_BUSY))
return;
dw_spi_xfer_done(dws);
spi_finalize_current_transfer(dws->master);
}

static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
Expand Down Expand Up @@ -155,7 +155,7 @@ static void dw_spi_dma_rx_done(void *arg)

if (test_and_clear_bit(RX_BUSY, &dws->dma_chan_busy) & BIT(TX_BUSY))
return;
dw_spi_xfer_done(dws);
spi_finalize_current_transfer(dws->master);
}

static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
Expand Down
183 changes: 47 additions & 136 deletions drivers/spi/spi-dw.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,11 +28,6 @@
#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)

/* Slave spi_dev related */
struct chip_data {
u16 cr0;
Expand Down Expand Up @@ -143,6 +138,19 @@ static inline void dw_spi_debugfs_remove(struct dw_spi *dws)
}
#endif /* CONFIG_DEBUG_FS */

static void dw_spi_set_cs(struct spi_device *spi, bool enable)
{
struct dw_spi *dws = spi_master_get_devdata(spi->master);
struct chip_data *chip = spi_get_ctldata(spi);

/* Chip select logic is inverted from spi_set_cs() */
if (chip->cs_control)
chip->cs_control(!enable);

if (!enable)
dw_writel(dws, DW_SPI_SER, BIT(spi->chip_select));
}

/* Return the max entries we can fill into tx fifo */
static inline u32 tx_max(struct dw_spi *dws)
{
Expand Down Expand Up @@ -209,93 +217,41 @@ static void dw_reader(struct dw_spi *dws)
}
}

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;
}

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)
static int map_dma_buffers(struct spi_master *master,
struct spi_device *spi, struct spi_transfer *transfer)
{
if (!dws->cur_msg->is_dma_mapped
struct dw_spi *dws = spi_master_get_devdata(master);
struct chip_data *chip = spi_get_ctldata(spi);

if (!master->cur_msg->is_dma_mapped
|| !dws->dma_inited
|| !dws->cur_chip->enable_dma
|| !chip->enable_dma
|| !dws->dma_ops)
return 0;

if (dws->cur_transfer->tx_dma)
dws->tx_dma = dws->cur_transfer->tx_dma;
if (transfer->tx_dma)
dws->tx_dma = transfer->tx_dma;

if (dws->cur_transfer->rx_dma)
dws->rx_dma = dws->cur_transfer->rx_dma;
if (transfer->rx_dma)
dws->rx_dma = 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;
struct spi_message *msg;

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;

last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
transfer_list);

if (!last_transfer->cs_change)
spi_chip_sel(dws, msg->spi, 0);

spi_finalize_current_message(dws->master);
}

static void int_error_stop(struct dw_spi *dws, const char *msg)
{
spi_reset_chip(dws);

dev_err(&dws->master->dev, "%s\n", msg);
dws->cur_msg->state = ERROR_STATE;
tasklet_schedule(&dws->pump_transfers);
dws->master->cur_msg->status = -EIO;
spi_finalize_current_transfer(dws->master);
}

void dw_spi_xfer_done(struct dw_spi *dws)
{
/* Update total byte transferred 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);
}
EXPORT_SYMBOL_GPL(dw_spi_xfer_done);

static irqreturn_t interrupt_transfer(struct dw_spi *dws)
{
u16 irq_status = dw_readw(dws, DW_SPI_ISR);
Expand All @@ -312,7 +268,7 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws)
dw_reader(dws);
if (dws->rx_end == dws->rx) {
spi_mask_intr(dws, SPI_INT_TXEI);
dw_spi_xfer_done(dws);
spi_finalize_current_transfer(dws->master);
return IRQ_HANDLED;
}
if (irq_status & SPI_INT_TXEI) {
Expand All @@ -327,13 +283,14 @@ static irqreturn_t interrupt_transfer(struct dw_spi *dws)

static irqreturn_t dw_spi_irq(int irq, void *dev_id)
{
struct dw_spi *dws = dev_id;
struct spi_master *master = dev_id;
struct dw_spi *dws = spi_master_get_devdata(master);
u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f;

if (!irq_status)
return IRQ_NONE;

if (!dws->cur_msg) {
if (!master->cur_msg) {
spi_mask_intr(dws, SPI_INT_TXEI);
return IRQ_HANDLED;
}
Expand All @@ -342,25 +299,22 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id)
}

/* Must be called inside pump_transfers() */
static void poll_transfer(struct dw_spi *dws)
static int poll_transfer(struct dw_spi *dws)
{
do {
dw_writer(dws);
dw_reader(dws);
cpu_relax();
} while (dws->rx_end > dws->rx);

dw_spi_xfer_done(dws);
return 0;
}

static void pump_transfers(unsigned long data)
static int dw_spi_transfer_one(struct spi_master *master,
struct spi_device *spi, struct spi_transfer *transfer)
{
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;
struct dw_spi *dws = spi_master_get_devdata(master);
struct chip_data *chip = spi_get_ctldata(spi);
u8 bits = 0;
u8 imask = 0;
u8 cs_change = 0;
Expand All @@ -369,43 +323,16 @@ static void pump_transfers(unsigned long data)
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 (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->len = dws->cur_transfer->len;
dws->len = transfer->len;
if (chip != dws->prev_chip)
cs_change = 1;

Expand Down Expand Up @@ -437,13 +364,12 @@ static void pump_transfers(unsigned long data)
| (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 (chip->cs_control) {
if (dws->rx && dws->tx)
chip->tmode = SPI_TMOD_TR;
else if (dws->rx)
Expand All @@ -456,10 +382,9 @@ static void pump_transfers(unsigned long data)
}

dw_writew(dws, DW_SPI_CTRL0, cr0);
spi_chip_sel(dws, spi, 1);

/* Check if current transfer is a DMA transaction */
dws->dma_mapped = map_dma_buffers(dws);
dws->dma_mapped = map_dma_buffers(master, spi, transfer);

/* For poll mode just disable all interrupts */
spi_mask_intr(dws, 0xff);
Expand Down Expand Up @@ -489,31 +414,17 @@ static void pump_transfers(unsigned long data)
dws->dma_ops->dma_transfer(dws, cs_change);

if (chip->poll_mode)
poll_transfer(dws);
return poll_transfer(dws);

return;

early_exit:
giveback(dws);
return 1;
}

static int dw_spi_transfer_one_message(struct spi_master *master,
static void dw_spi_handle_err(struct spi_master *master,
struct spi_message *msg)
{
struct dw_spi *dws = spi_master_get_devdata(master);

dws->cur_msg = msg;
/* 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);

/* Launch transfers */
tasklet_schedule(&dws->pump_transfers);

return 0;
spi_reset_chip(dws);
}

/* This may be called twice for each spi dev */
Expand Down Expand Up @@ -637,7 +548,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
snprintf(dws->name, sizeof(dws->name), "dw_spi%d", dws->bus_num);

ret = devm_request_irq(dev, dws->irq, dw_spi_irq, IRQF_SHARED,
dws->name, dws);
dws->name, master);
if (ret < 0) {
dev_err(&master->dev, "can not get IRQ\n");
goto err_free_master;
Expand All @@ -649,7 +560,9 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
master->num_chipselect = dws->num_cs;
master->setup = dw_spi_setup;
master->cleanup = dw_spi_cleanup;
master->transfer_one_message = dw_spi_transfer_one_message;
master->set_cs = dw_spi_set_cs;
master->transfer_one = dw_spi_transfer_one;
master->handle_err = dw_spi_handle_err;
master->max_speed_hz = dws->max_freq;
master->dev.of_node = dev->of_node;

Expand All @@ -664,8 +577,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
}
}

tasklet_init(&dws->pump_transfers, pump_transfers, (unsigned long)dws);

spi_master_set_devdata(master, dws);
ret = devm_spi_register_master(dev, master);
if (ret) {
Expand Down
Loading

0 comments on commit c22c62d

Please sign in to comment.