#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h> /* FIXME: using chip internals */
+#include <linux/gpio/driver.h> /* FIXME: using chip internals */
#include <linux/of_irq.h>
#include <linux/spi/spi.h>
* @rx_prologue: bytes received without DMA if first RX sglist entry's
* length is not a multiple of 4 (to overcome hardware limitation)
* @tx_spillover: whether @tx_prologue spills over to second TX sglist entry
- * @dma_pending: whether a DMA transfer is in progress
* @debugfs_dir: the debugfs directory - neede to remove debugfs when
* unloading the module
* @count_transfer_polling: count of how often polling mode is used
int tx_prologue;
int rx_prologue;
unsigned int tx_spillover;
- unsigned int dma_pending;
struct dentry *debugfs_dir;
u64 count_transfer_polling;
sg_dma_address(&tfr->tx_sg.sgl[1]) -= 4;
sg_dma_len(&tfr->tx_sg.sgl[1]) += 4;
}
+
+ bs->tx_prologue = 0;
}
static void bcm2835_spi_dma_done(void *data)
* is called the tx-dma must have finished - can't get to this
* situation otherwise...
*/
- if (cmpxchg(&bs->dma_pending, true, false)) {
- dmaengine_terminate_async(ctlr->dma_tx);
- bcm2835_spi_undo_prologue(bs);
- }
+ dmaengine_terminate_async(ctlr->dma_tx);
+ bcm2835_spi_undo_prologue(bs);
/* and mark as completed */;
complete(&ctlr->xfer_completion);
/* start TX early */
dma_async_issue_pending(ctlr->dma_tx);
- /* mark as dma pending */
- bs->dma_pending = 1;
-
/* set the DMA length */
bcm2835_wr(bs, BCM2835_SPI_DLEN, bs->tx_len);
if (ret) {
/* need to reset on errors */
dmaengine_terminate_sync(ctlr->dma_tx);
- bs->dma_pending = false;
goto err_reset_hw;
}
bcm2835_wr(bs, BCM2835_SPI_CLK, cdiv);
/* handle all the 3-wire mode */
- if ((spi->mode & SPI_3WIRE) && (tfr->rx_buf))
+ if (spi->mode & SPI_3WIRE && tfr->rx_buf &&
+ tfr->rx_buf != ctlr->dummy_rx)
cs |= BCM2835_SPI_CS_REN;
else
cs &= ~BCM2835_SPI_CS_REN;
struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr);
/* if an error occurred and we have an active dma, then terminate */
- if (cmpxchg(&bs->dma_pending, true, false)) {
- dmaengine_terminate_sync(ctlr->dma_tx);
- dmaengine_terminate_sync(ctlr->dma_rx);
- bcm2835_spi_undo_prologue(bs);
- }
+ dmaengine_terminate_sync(ctlr->dma_tx);
+ dmaengine_terminate_sync(ctlr->dma_rx);
+ bcm2835_spi_undo_prologue(bs);
+
/* and reset */
bcm2835_spi_reset_hw(ctlr);
}
static int bcm2835_spi_setup(struct spi_device *spi)
{
- int err;
struct gpio_chip *chip;
+ enum gpio_lookup_flags lflags;
+
/*
* sanity checking the native-chipselects
*/
if (spi->mode & SPI_NO_CS)
return 0;
- if (gpio_is_valid(spi->cs_gpio))
+ /*
+ * The SPI core has successfully requested the CS GPIO line from the
+ * device tree, so we are done.
+ */
+ if (spi->cs_gpiod)
return 0;
if (spi->chip_select > 1) {
/* error in the case of native CS requested with CS > 1
"setup: only two native chip-selects are supported\n");
return -EINVAL;
}
- /* now translate native cs to GPIO */
+
+ /*
+ * Translate native CS to GPIO
+ *
+ * FIXME: poking around in the gpiolib internals like this is
+ * not very good practice. Find a way to locate the real problem
+ * and fix it. Why is the GPIO descriptor in spi->cs_gpiod
+ * sometimes not assigned correctly? Erroneous device trees?
+ */
/* get the gpio chip for the base */
chip = gpiochip_find("pinctrl-bcm2835", chip_match_name);
if (!chip)
return 0;
- /* and calculate the real CS */
- spi->cs_gpio = chip->base + 8 - spi->chip_select;
+ /*
+ * Retrieve the corresponding GPIO line used for CS.
+ * The inversion semantics will be handled by the GPIO core
+ * code, so we pass GPIOS_OUT_LOW for "unasserted" and
+ * the correct flag for inversion semantics. The SPI_CS_HIGH
+ * on spi->mode cannot be checked for polarity in this case
+ * as the flag use_gpio_descriptors enforces SPI_CS_HIGH.
+ */
+ if (of_property_read_bool(spi->dev.of_node, "spi-cs-high"))
+ lflags = GPIO_ACTIVE_HIGH;
+ else
+ lflags = GPIO_ACTIVE_LOW;
+ spi->cs_gpiod = gpiochip_request_own_desc(chip, 8 - spi->chip_select,
+ DRV_NAME,
+ lflags,
+ GPIOD_OUT_LOW);
+ if (IS_ERR(spi->cs_gpiod))
+ return PTR_ERR(spi->cs_gpiod);
/* and set up the "mode" and level */
- dev_info(&spi->dev, "setting up native-CS%i as GPIO %i\n",
- spi->chip_select, spi->cs_gpio);
-
- /* set up GPIO as output and pull to the correct level */
- err = gpio_direction_output(spi->cs_gpio,
- (spi->mode & SPI_CS_HIGH) ? 0 : 1);
- if (err) {
- dev_err(&spi->dev,
- "could not set CS%i gpio %i as output: %i",
- spi->chip_select, spi->cs_gpio, err);
- return err;
- }
+ dev_info(&spi->dev, "setting up native-CS%i to use GPIO\n",
+ spi->chip_select);
return 0;
}
{
struct spi_controller *ctlr;
struct bcm2835_spi *bs;
- struct resource *res;
int err;
ctlr = spi_alloc_master(&pdev->dev, sizeof(*bs));
platform_set_drvdata(pdev, ctlr);
+ ctlr->use_gpio_descriptors = true;
ctlr->mode_bits = BCM2835_SPI_MODE_BITS;
ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
ctlr->num_chipselect = 3;
bs = spi_controller_get_devdata(ctlr);
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- bs->regs = devm_ioremap_resource(&pdev->dev, res);
+ bs->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(bs->regs)) {
err = PTR_ERR(bs->regs);
goto out_controller_put;
bs->irq = platform_get_irq(pdev, 0);
if (bs->irq <= 0) {
- dev_err(&pdev->dev, "could not get IRQ: %d\n", bs->irq);
err = bs->irq ? bs->irq : -ENODEV;
goto out_controller_put;
}
projects / linux.git / blobdiff