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Diffstat (limited to 'drivers/spi/spi-atmel.c')
-rw-r--r--drivers/spi/spi-atmel.c324
1 files changed, 142 insertions, 182 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 8feac599e9ab..0e7712bac3b6 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -24,6 +24,7 @@
#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm_runtime.h>
@@ -264,17 +265,6 @@
#define AUTOSUSPEND_TIMEOUT 2000
-struct atmel_spi_dma {
- struct dma_chan *chan_rx;
- struct dma_chan *chan_tx;
- struct scatterlist sgrx;
- struct scatterlist sgtx;
- struct dma_async_tx_descriptor *data_desc_rx;
- struct dma_async_tx_descriptor *data_desc_tx;
-
- struct at_dma_slave dma_slave;
-};
-
struct atmel_spi_caps {
bool is_spi2;
bool has_wdrbt;
@@ -295,6 +285,7 @@ struct atmel_spi {
int irq;
struct clk *clk;
struct platform_device *pdev;
+ unsigned long spi_clk;
struct spi_transfer *current_transfer;
int current_remaining_bytes;
@@ -302,17 +293,11 @@ struct atmel_spi {
struct completion xfer_completion;
- /* scratch buffer */
- void *buffer;
- dma_addr_t buffer_dma;
-
struct atmel_spi_caps caps;
bool use_dma;
bool use_pdc;
bool use_cs_gpios;
- /* dmaengine data */
- struct atmel_spi_dma dma;
bool keep_cs;
bool cs_active;
@@ -326,7 +311,7 @@ struct atmel_spi_device {
u32 csr;
};
-#define BUFFER_SIZE PAGE_SIZE
+#define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */
#define INVALID_DMA_ADDRESS 0xffffffff
/*
@@ -456,10 +441,20 @@ static inline bool atmel_spi_use_dma(struct atmel_spi *as,
return as->use_dma && xfer->len >= DMA_MIN_BYTES;
}
+static bool atmel_spi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct atmel_spi *as = spi_master_get_devdata(master);
+
+ return atmel_spi_use_dma(as, xfer);
+}
+
static int atmel_spi_dma_slave_config(struct atmel_spi *as,
struct dma_slave_config *slave_config,
u8 bits_per_word)
{
+ struct spi_master *master = platform_get_drvdata(as->pdev);
int err = 0;
if (bits_per_word > 8) {
@@ -491,7 +486,7 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
* path works the same whether FIFOs are available (and enabled) or not.
*/
slave_config->direction = DMA_MEM_TO_DEV;
- if (dmaengine_slave_config(as->dma.chan_tx, slave_config)) {
+ if (dmaengine_slave_config(master->dma_tx, slave_config)) {
dev_err(&as->pdev->dev,
"failed to configure tx dma channel\n");
err = -EINVAL;
@@ -506,7 +501,7 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
* enabled) or not.
*/
slave_config->direction = DMA_DEV_TO_MEM;
- if (dmaengine_slave_config(as->dma.chan_rx, slave_config)) {
+ if (dmaengine_slave_config(master->dma_rx, slave_config)) {
dev_err(&as->pdev->dev,
"failed to configure rx dma channel\n");
err = -EINVAL;
@@ -515,7 +510,8 @@ static int atmel_spi_dma_slave_config(struct atmel_spi *as,
return err;
}
-static int atmel_spi_configure_dma(struct atmel_spi *as)
+static int atmel_spi_configure_dma(struct spi_master *master,
+ struct atmel_spi *as)
{
struct dma_slave_config slave_config;
struct device *dev = &as->pdev->dev;
@@ -525,26 +521,26 @@ static int atmel_spi_configure_dma(struct atmel_spi *as)
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
- as->dma.chan_tx = dma_request_slave_channel_reason(dev, "tx");
- if (IS_ERR(as->dma.chan_tx)) {
- err = PTR_ERR(as->dma.chan_tx);
+ master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
+ if (IS_ERR(master->dma_tx)) {
+ err = PTR_ERR(master->dma_tx);
if (err == -EPROBE_DEFER) {
dev_warn(dev, "no DMA channel available at the moment\n");
- return err;
+ goto error_clear;
}
dev_err(dev,
"DMA TX channel not available, SPI unable to use DMA\n");
err = -EBUSY;
- goto error;
+ goto error_clear;
}
/*
* No reason to check EPROBE_DEFER here since we have already requested
* tx channel. If it fails here, it's for another reason.
*/
- as->dma.chan_rx = dma_request_slave_channel(dev, "rx");
+ master->dma_rx = dma_request_slave_channel(dev, "rx");
- if (!as->dma.chan_rx) {
+ if (!master->dma_rx) {
dev_err(dev,
"DMA RX channel not available, SPI unable to use DMA\n");
err = -EBUSY;
@@ -557,31 +553,38 @@ static int atmel_spi_configure_dma(struct atmel_spi *as)
dev_info(&as->pdev->dev,
"Using %s (tx) and %s (rx) for DMA transfers\n",
- dma_chan_name(as->dma.chan_tx),
- dma_chan_name(as->dma.chan_rx));
+ dma_chan_name(master->dma_tx),
+ dma_chan_name(master->dma_rx));
+
return 0;
error:
- if (as->dma.chan_rx)
- dma_release_channel(as->dma.chan_rx);
- if (!IS_ERR(as->dma.chan_tx))
- dma_release_channel(as->dma.chan_tx);
+ if (master->dma_rx)
+ dma_release_channel(master->dma_rx);
+ if (!IS_ERR(master->dma_tx))
+ dma_release_channel(master->dma_tx);
+error_clear:
+ master->dma_tx = master->dma_rx = NULL;
return err;
}
-static void atmel_spi_stop_dma(struct atmel_spi *as)
+static void atmel_spi_stop_dma(struct spi_master *master)
{
- if (as->dma.chan_rx)
- dmaengine_terminate_all(as->dma.chan_rx);
- if (as->dma.chan_tx)
- dmaengine_terminate_all(as->dma.chan_tx);
+ if (master->dma_rx)
+ dmaengine_terminate_all(master->dma_rx);
+ if (master->dma_tx)
+ dmaengine_terminate_all(master->dma_tx);
}
-static void atmel_spi_release_dma(struct atmel_spi *as)
+static void atmel_spi_release_dma(struct spi_master *master)
{
- if (as->dma.chan_rx)
- dma_release_channel(as->dma.chan_rx);
- if (as->dma.chan_tx)
- dma_release_channel(as->dma.chan_tx);
+ if (master->dma_rx) {
+ dma_release_channel(master->dma_rx);
+ master->dma_rx = NULL;
+ }
+ if (master->dma_tx) {
+ dma_release_channel(master->dma_tx);
+ master->dma_tx = NULL;
+ }
}
/* This function is called by the DMA driver from tasklet context */
@@ -611,14 +614,10 @@ static void atmel_spi_next_xfer_single(struct spi_master *master,
cpu_relax();
}
- if (xfer->tx_buf) {
- if (xfer->bits_per_word > 8)
- spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
- else
- spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
- } else {
- spi_writel(as, TDR, 0);
- }
+ if (xfer->bits_per_word > 8)
+ spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
+ else
+ spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
dev_dbg(master->dev.parent,
" start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
@@ -665,17 +664,12 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master,
/* Fill TX FIFO */
while (num_data >= 2) {
- if (xfer->tx_buf) {
- if (xfer->bits_per_word > 8) {
- td0 = *words++;
- td1 = *words++;
- } else {
- td0 = *bytes++;
- td1 = *bytes++;
- }
+ if (xfer->bits_per_word > 8) {
+ td0 = *words++;
+ td1 = *words++;
} else {
- td0 = 0;
- td1 = 0;
+ td0 = *bytes++;
+ td1 = *bytes++;
}
spi_writel(as, TDR, (td1 << 16) | td0);
@@ -683,14 +677,10 @@ static void atmel_spi_next_xfer_fifo(struct spi_master *master,
}
if (num_data) {
- if (xfer->tx_buf) {
- if (xfer->bits_per_word > 8)
- td0 = *words++;
- else
- td0 = *bytes++;
- } else {
- td0 = 0;
- }
+ if (xfer->bits_per_word > 8)
+ td0 = *words++;
+ else
+ td0 = *bytes++;
spi_writew(as, TDR, td0);
num_data--;
@@ -730,13 +720,12 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
u32 *plen)
{
struct atmel_spi *as = spi_master_get_devdata(master);
- struct dma_chan *rxchan = as->dma.chan_rx;
- struct dma_chan *txchan = as->dma.chan_tx;
+ struct dma_chan *rxchan = master->dma_rx;
+ struct dma_chan *txchan = master->dma_tx;
struct dma_async_tx_descriptor *rxdesc;
struct dma_async_tx_descriptor *txdesc;
struct dma_slave_config slave_config;
dma_cookie_t cookie;
- u32 len = *plen;
dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n");
@@ -747,44 +736,22 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
/* release lock for DMA operations */
atmel_spi_unlock(as);
- /* prepare the RX dma transfer */
- sg_init_table(&as->dma.sgrx, 1);
- if (xfer->rx_buf) {
- as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen;
- } else {
- as->dma.sgrx.dma_address = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- }
-
- /* prepare the TX dma transfer */
- sg_init_table(&as->dma.sgtx, 1);
- if (xfer->tx_buf) {
- as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen;
- } else {
- as->dma.sgtx.dma_address = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- memset(as->buffer, 0, len);
- }
-
- sg_dma_len(&as->dma.sgtx) = len;
- sg_dma_len(&as->dma.sgrx) = len;
-
- *plen = len;
+ *plen = xfer->len;
if (atmel_spi_dma_slave_config(as, &slave_config,
xfer->bits_per_word))
goto err_exit;
/* Send both scatterlists */
- rxdesc = dmaengine_prep_slave_sg(rxchan, &as->dma.sgrx, 1,
+ rxdesc = dmaengine_prep_slave_sg(rxchan,
+ xfer->rx_sg.sgl, xfer->rx_sg.nents,
DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!rxdesc)
goto err_dma;
- txdesc = dmaengine_prep_slave_sg(txchan, &as->dma.sgtx, 1,
+ txdesc = dmaengine_prep_slave_sg(txchan,
+ xfer->tx_sg.sgl, xfer->tx_sg.nents,
DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc)
@@ -818,7 +785,7 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
err_dma:
spi_writel(as, IDR, SPI_BIT(OVRES));
- atmel_spi_stop_dma(as);
+ atmel_spi_stop_dma(master);
err_exit:
atmel_spi_lock(as);
return -ENOMEM;
@@ -830,30 +797,10 @@ static void atmel_spi_next_xfer_data(struct spi_master *master,
dma_addr_t *rx_dma,
u32 *plen)
{
- struct atmel_spi *as = spi_master_get_devdata(master);
- u32 len = *plen;
-
- /* use scratch buffer only when rx or tx data is unspecified */
- if (xfer->rx_buf)
- *rx_dma = xfer->rx_dma + xfer->len - *plen;
- else {
- *rx_dma = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- }
-
- if (xfer->tx_buf)
- *tx_dma = xfer->tx_dma + xfer->len - *plen;
- else {
- *tx_dma = as->buffer_dma;
- if (len > BUFFER_SIZE)
- len = BUFFER_SIZE;
- memset(as->buffer, 0, len);
- dma_sync_single_for_device(&as->pdev->dev,
- as->buffer_dma, len, DMA_TO_DEVICE);
- }
-
- *plen = len;
+ *rx_dma = xfer->rx_dma + xfer->len - *plen;
+ *tx_dma = xfer->tx_dma + xfer->len - *plen;
+ if (*plen > master->max_dma_len)
+ *plen = master->max_dma_len;
}
static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
@@ -864,7 +811,7 @@ static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
unsigned long bus_hz;
/* v1 chips start out at half the peripheral bus speed. */
- bus_hz = clk_get_rate(as->clk);
+ bus_hz = as->spi_clk;
if (!atmel_spi_is_v2(as))
bus_hz /= 2;
@@ -1025,16 +972,12 @@ atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer)
u16 *rxp16;
unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
- if (xfer->rx_buf) {
- if (xfer->bits_per_word > 8) {
- rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
- *rxp16 = spi_readl(as, RDR);
- } else {
- rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
- *rxp = spi_readl(as, RDR);
- }
+ if (xfer->bits_per_word > 8) {
+ rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
+ *rxp16 = spi_readl(as, RDR);
} else {
- spi_readl(as, RDR);
+ rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
+ *rxp = spi_readl(as, RDR);
}
if (xfer->bits_per_word > 8) {
if (as->current_remaining_bytes > 2)
@@ -1073,12 +1016,10 @@ atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer)
/* Read data */
while (num_data) {
rd = spi_readl(as, RDR);
- if (xfer->rx_buf) {
- if (xfer->bits_per_word > 8)
- *words++ = rd;
- else
- *bytes++ = rd;
- }
+ if (xfer->bits_per_word > 8)
+ *words++ = rd;
+ else
+ *bytes++ = rd;
num_data--;
}
}
@@ -1204,7 +1145,6 @@ static int atmel_spi_setup(struct spi_device *spi)
u32 csr;
unsigned int bits = spi->bits_per_word;
unsigned int npcs_pin;
- int ret;
as = spi_master_get_devdata(spi->master);
@@ -1247,16 +1187,9 @@ static int atmel_spi_setup(struct spi_device *spi)
if (!asd)
return -ENOMEM;
- if (as->use_cs_gpios) {
- ret = gpio_request(npcs_pin, dev_name(&spi->dev));
- if (ret) {
- kfree(asd);
- return ret;
- }
-
+ if (as->use_cs_gpios)
gpio_direction_output(npcs_pin,
!(spi->mode & SPI_CS_HIGH));
- }
asd->npcs_pin = npcs_pin;
spi->controller_state = asd;
@@ -1307,7 +1240,7 @@ static int atmel_spi_one_transfer(struct spi_master *master,
* better fault reporting.
*/
if ((!msg->is_dma_mapped)
- && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) {
+ && as->use_pdc) {
if (atmel_spi_dma_map_xfer(as, xfer) < 0)
return -ENOMEM;
}
@@ -1380,11 +1313,11 @@ static int atmel_spi_one_transfer(struct spi_master *master,
spi_readl(as, SR);
} else if (atmel_spi_use_dma(as, xfer)) {
- atmel_spi_stop_dma(as);
+ atmel_spi_stop_dma(master);
}
if (!msg->is_dma_mapped
- && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
+ && as->use_pdc)
atmel_spi_dma_unmap_xfer(master, xfer);
return 0;
@@ -1395,7 +1328,7 @@ static int atmel_spi_one_transfer(struct spi_master *master,
}
if (!msg->is_dma_mapped
- && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
+ && as->use_pdc)
atmel_spi_dma_unmap_xfer(master, xfer);
if (xfer->delay_usecs)
@@ -1471,13 +1404,11 @@ msg_done:
static void atmel_spi_cleanup(struct spi_device *spi)
{
struct atmel_spi_device *asd = spi->controller_state;
- unsigned gpio = (unsigned long) spi->controller_data;
if (!asd)
return;
spi->controller_state = NULL;
- gpio_free(gpio);
kfree(asd);
}
@@ -1499,6 +1430,39 @@ static void atmel_get_caps(struct atmel_spi *as)
}
/*-------------------------------------------------------------------------*/
+static int atmel_spi_gpio_cs(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct atmel_spi *as = spi_master_get_devdata(master);
+ struct device_node *np = master->dev.of_node;
+ int i;
+ int ret = 0;
+ int nb = 0;
+
+ if (!as->use_cs_gpios)
+ return 0;
+
+ if (!np)
+ return 0;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ for (i = 0; i < nb; i++) {
+ int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
+ "cs-gpios", i);
+
+ if (cs_gpio == -EPROBE_DEFER)
+ return cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ ret = devm_gpio_request(&pdev->dev, cs_gpio,
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
static int atmel_spi_probe(struct platform_device *pdev)
{
@@ -1537,29 +1501,23 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->bus_num = pdev->id;
master->num_chipselect = master->dev.of_node ? 0 : 4;
master->setup = atmel_spi_setup;
+ master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
master->transfer_one_message = atmel_spi_transfer_one_message;
master->cleanup = atmel_spi_cleanup;
master->auto_runtime_pm = true;
+ master->max_dma_len = SPI_MAX_DMA_XFER;
+ master->can_dma = atmel_spi_can_dma;
platform_set_drvdata(pdev, master);
as = spi_master_get_devdata(master);
- /*
- * Scratch buffer is used for throwaway rx and tx data.
- * It's coherent to minimize dcache pollution.
- */
- as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,
- &as->buffer_dma, GFP_KERNEL);
- if (!as->buffer)
- goto out_free;
-
spin_lock_init(&as->lock);
as->pdev = pdev;
as->regs = devm_ioremap_resource(&pdev->dev, regs);
if (IS_ERR(as->regs)) {
ret = PTR_ERR(as->regs);
- goto out_free_buffer;
+ goto out_unmap_regs;
}
as->phybase = regs->start;
as->irq = irq;
@@ -1577,14 +1535,19 @@ static int atmel_spi_probe(struct platform_device *pdev)
master->num_chipselect = 4;
}
+ ret = atmel_spi_gpio_cs(pdev);
+ if (ret)
+ goto out_unmap_regs;
+
as->use_dma = false;
as->use_pdc = false;
if (as->caps.has_dma_support) {
- ret = atmel_spi_configure_dma(as);
- if (ret == 0)
+ ret = atmel_spi_configure_dma(master, as);
+ if (ret == 0) {
as->use_dma = true;
- else if (ret == -EPROBE_DEFER)
+ } else if (ret == -EPROBE_DEFER) {
return ret;
+ }
} else {
as->use_pdc = true;
}
@@ -1606,6 +1569,9 @@ static int atmel_spi_probe(struct platform_device *pdev)
ret = clk_prepare_enable(clk);
if (ret)
goto out_free_irq;
+
+ as->spi_clk = clk_get_rate(clk);
+
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
if (as->caps.has_wdrbt) {
@@ -1626,10 +1592,6 @@ static int atmel_spi_probe(struct platform_device *pdev)
spi_writel(as, CR, SPI_BIT(FIFOEN));
}
- /* go! */
- dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n",
- (unsigned long)regs->start, irq);
-
pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
@@ -1639,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device *pdev)
if (ret)
goto out_free_dma;
+ /* go! */
+ dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n",
+ (unsigned long)regs->start, irq);
+
return 0;
out_free_dma:
@@ -1646,16 +1612,13 @@ out_free_dma:
pm_runtime_set_suspended(&pdev->dev);
if (as->use_dma)
- atmel_spi_release_dma(as);
+ atmel_spi_release_dma(master);
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
clk_disable_unprepare(clk);
out_free_irq:
out_unmap_regs:
-out_free_buffer:
- dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
- as->buffer_dma);
out_free:
spi_master_put(master);
return ret;
@@ -1671,8 +1634,8 @@ static int atmel_spi_remove(struct platform_device *pdev)
/* reset the hardware and block queue progress */
spin_lock_irq(&as->lock);
if (as->use_dma) {
- atmel_spi_stop_dma(as);
- atmel_spi_release_dma(as);
+ atmel_spi_stop_dma(master);
+ atmel_spi_release_dma(master);
}
spi_writel(as, CR, SPI_BIT(SWRST));
@@ -1680,9 +1643,6 @@ static int atmel_spi_remove(struct platform_device *pdev)
spi_readl(as, SR);
spin_unlock_irq(&as->lock);
- dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
- as->buffer_dma);
-
clk_disable_unprepare(as->clk);
pm_runtime_put_noidle(&pdev->dev);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-24 22:54:38 +0000