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authorSimon Glass <sjg@chromium.org>2015-06-05 14:39:33 -0600
committerTom Warren <twarren@nvidia.com>2015-06-09 09:56:13 -0700
commit635c2515c398241f59c5936213308ce9709fc475 (patch)
tree1884ffbf8d2c6639e1c509e0e345a678c0007c1f /drivers
parentbbe0d4db53e30affae1194882075e1e0997c4c5c (diff)
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tegra: spi: Drop the claim_bus() method to correct delays
At present the driver does not properly honour the requested SPI CS deactivation delay since the SPI bus is changed in the claim_bus() method. Everything the claim_bus() method does can be done when the device is probed (setting the speed and mode) and at the start of a new transfer (where the fifo_status is already cleared). So drop this method. Also, until the delay is complete, we should not touch the bus, so make sure that spi_cs_activate() is called before other things are done in the xfer() method. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Tom Warren <twarren@nvidia.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/tegra114_spi.c26
1 files changed, 9 insertions, 17 deletions
diff --git a/drivers/spi/tegra114_spi.c b/drivers/spi/tegra114_spi.c
index 4bec663..0d69376 100644
--- a/drivers/spi/tegra114_spi.c
+++ b/drivers/spi/tegra114_spi.c
@@ -143,24 +143,18 @@ static int tegra114_spi_probe(struct udevice *bus)
{
struct tegra_spi_platdata *plat = dev_get_platdata(bus);
struct tegra114_spi_priv *priv = dev_get_priv(bus);
+ struct spi_regs *regs;
priv->regs = (struct spi_regs *)plat->base;
+ regs = priv->regs;
priv->last_transaction_us = timer_get_us();
priv->freq = plat->frequency;
priv->periph_id = plat->periph_id;
- return 0;
-}
-
-static int tegra114_spi_claim_bus(struct udevice *dev)
-{
- struct udevice *bus = dev->parent;
- struct tegra114_spi_priv *priv = dev_get_priv(bus);
- struct spi_regs *regs = priv->regs;
-
/* Change SPI clock to correct frequency, PLLP_OUT0 source */
- clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
+ clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH,
+ priv->freq);
/* Clear stale status here */
setbits_le32(&regs->fifo_status,
@@ -175,9 +169,8 @@ static int tegra114_spi_claim_bus(struct udevice *dev)
SPI_FIFO_STS_RX_FIFO_EMPTY);
debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
- /* Set master mode and sw controlled CS */
- setbits_le32(&regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |
- (priv->mode << SPI_CMD1_MODE_SHIFT));
+ setbits_le32(&priv->regs->command1, SPI_CMD1_M_S | SPI_CMD1_CS_SW_HW |
+ (priv->mode << SPI_CMD1_MODE_SHIFT) | SPI_CMD1_CS_SW_VAL);
debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
return 0;
@@ -249,6 +242,9 @@ static int tegra114_spi_xfer(struct udevice *dev, unsigned int bitlen,
ret = 0;
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(dev);
+
/* clear all error status bits */
reg = readl(&regs->fifo_status);
writel(reg, &regs->fifo_status);
@@ -260,9 +256,6 @@ static int tegra114_spi_xfer(struct udevice *dev, unsigned int bitlen,
/* set xfer size to 1 block (32 bits) */
writel(0, &regs->dma_blk);
- if (flags & SPI_XFER_BEGIN)
- spi_cs_activate(dev);
-
/* handle data in 32-bit chunks */
while (num_bytes > 0) {
int bytes;
@@ -385,7 +378,6 @@ static int tegra114_spi_set_mode(struct udevice *bus, uint mode)
}
static const struct dm_spi_ops tegra114_spi_ops = {
- .claim_bus = tegra114_spi_claim_bus,
.xfer = tegra114_spi_xfer,
.set_speed = tegra114_spi_set_speed,
.set_mode = tegra114_spi_set_mode,