resend: [PATCH] amba_pl022: Setup SPI configuration based on spi->mode
Kevin Wells
wellsk40 at gmail.com
Fri Sep 10 18:57:57 EDT 2010
(Re-send with full distribution list)
This patch changes the way SPI transfers are setup. The previous
method uses the pl022_config_chip data for configuration of
loopback mode, edge count, clock polarity, number of data bits,
and bit transfer order. This change configures these parameters
based on spi->mode passed via master->setup and will allow the
drivers use SPI to configure the interface.
The fields lbm, clk_phase, clk_pol, and data_size are no longer
needed. For the ST/pl023 setup, the first bit transferred for
both RX and TX is now selected with the SPI_LSB_FIRST flag in
spi->mode.
There are also several very minor cleanups in the patch that
fix return status on setup failures.
This has been tested with the AT25 serial EEPROM driver and
spidev modes 0-3 with loopback and varying data sizes.
Reported-by: Quentin Yang <quentinyang05 at gmail.com>
Signed-off-by: Kevin Wells <wellsk40 at gmail.com>
---
drivers/spi/amba-pl022.c | 121 ++++++++++++++++++++--------------------------
1 files changed, 53 insertions(+), 68 deletions(-)
diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
index acd35d1..1be488a 100644
--- a/drivers/spi/amba-pl022.c
+++ b/drivers/spi/amba-pl022.c
@@ -1248,12 +1248,6 @@ static int destroy_queue(struct pl022 *pl022)
static int verify_controller_parameters(struct pl022 *pl022,
struct pl022_config_chip *chip_info)
{
- if ((chip_info->lbm != LOOPBACK_ENABLED)
- && (chip_info->lbm != LOOPBACK_DISABLED)) {
- dev_err(chip_info->dev,
- "loopback Mode is configured incorrectly\n");
- return -EINVAL;
- }
if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
|| (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
dev_err(chip_info->dev,
@@ -1279,24 +1273,6 @@ static int verify_controller_parameters(struct
pl022 *pl022,
"cpsdvsr is configured incorrectly\n");
return -EINVAL;
}
- if ((chip_info->endian_rx != SSP_RX_MSB)
- && (chip_info->endian_rx != SSP_RX_LSB)) {
- dev_err(chip_info->dev,
- "RX FIFO endianess is configured incorrectly\n");
- return -EINVAL;
- }
- if ((chip_info->endian_tx != SSP_TX_MSB)
- && (chip_info->endian_tx != SSP_TX_LSB)) {
- dev_err(chip_info->dev,
- "TX FIFO endianess is configured incorrectly\n");
- return -EINVAL;
- }
- if ((chip_info->data_size < SSP_DATA_BITS_4)
- || (chip_info->data_size > SSP_DATA_BITS_32)) {
- dev_err(chip_info->dev,
- "DATA Size is configured incorrectly\n");
- return -EINVAL;
- }
if ((chip_info->com_mode != INTERRUPT_TRANSFER)
&& (chip_info->com_mode != DMA_TRANSFER)
&& (chip_info->com_mode != POLLING_TRANSFER)) {
@@ -1316,20 +1292,6 @@ static int verify_controller_parameters(struct
pl022 *pl022,
"TX FIFO Trigger Level is configured incorrectly\n");
return -EINVAL;
}
- if (chip_info->iface == SSP_INTERFACE_MOTOROLA_SPI) {
- if ((chip_info->clk_phase != SSP_CLK_FIRST_EDGE)
- && (chip_info->clk_phase != SSP_CLK_SECOND_EDGE)) {
- dev_err(chip_info->dev,
- "Clock Phase is configured incorrectly\n");
- return -EINVAL;
- }
- if ((chip_info->clk_pol != SSP_CLK_POL_IDLE_LOW)
- && (chip_info->clk_pol != SSP_CLK_POL_IDLE_HIGH)) {
- dev_err(chip_info->dev,
- "Clock Polarity is configured incorrectly\n");
- return -EINVAL;
- }
- }
if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
if ((chip_info->ctrl_len < SSP_BITS_4)
|| (chip_info->ctrl_len > SSP_BITS_32)) {
@@ -1494,23 +1456,14 @@ static int process_dma_info(struct
pl022_config_chip *chip_info,
* controller hardware here, that is not done until the actual transfer
* commence.
*/
-
-/* FIXME: JUST GUESSING the spi->mode bits understood by this driver */
-#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
- | SPI_LSB_FIRST | SPI_LOOP)
-
static int pl022_setup(struct spi_device *spi)
{
struct pl022_config_chip *chip_info;
struct chip_data *chip;
int status = 0;
struct pl022 *pl022 = spi_master_get_devdata(spi->master);
-
- if (spi->mode & ~MODEBITS) {
- dev_dbg(&spi->dev, "unsupported mode bits %x\n",
- spi->mode & ~MODEBITS);
- return -EINVAL;
- }
+ unsigned int bits = spi->bits_per_word;
+ u32 tmp;
if (!spi->max_speed_hz)
return -EINVAL;
@@ -1555,18 +1508,12 @@ static int pl022_setup(struct spi_device *spi)
* Set controller data default values:
* Polling is supported by default
*/
- chip_info->lbm = LOOPBACK_DISABLED;
chip_info->com_mode = POLLING_TRANSFER;
chip_info->iface = SSP_INTERFACE_MOTOROLA_SPI;
chip_info->hierarchy = SSP_SLAVE;
chip_info->slave_tx_disable = DO_NOT_DRIVE_TX;
- chip_info->endian_tx = SSP_TX_LSB;
- chip_info->endian_rx = SSP_RX_LSB;
- chip_info->data_size = SSP_DATA_BITS_12;
chip_info->rx_lev_trig = SSP_RX_1_OR_MORE_ELEM;
chip_info->tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC;
- chip_info->clk_phase = SSP_CLK_SECOND_EDGE;
- chip_info->clk_pol = SSP_CLK_POL_IDLE_LOW;
chip_info->ctrl_len = SSP_BITS_8;
chip_info->wait_state = SSP_MWIRE_WAIT_ZERO;
chip_info->duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX;
@@ -1601,12 +1548,16 @@ static int pl022_setup(struct spi_device *spi)
chip->xfer_type = chip_info->com_mode;
chip->cs_control = chip_info->cs_control;
- if (chip_info->data_size <= 8) {
- dev_dbg(&spi->dev, "1 <= n <=8 bits per word\n");
+ if (bits <= 3) {
+ /* PL022 doesn't support less than 4-bits */
+ status = -ENOTSUPP;
+ goto err_config_params;
+ } else if (bits <= 8) {
+ dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
chip->n_bytes = 1;
chip->read = READING_U8;
chip->write = WRITING_U8;
- } else if (chip_info->data_size <= 16) {
+ } else if (bits <= 16) {
dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
chip->n_bytes = 2;
chip->read = READING_U16;
@@ -1623,6 +1574,7 @@ static int pl022_setup(struct spi_device *spi)
dev_err(&spi->dev,
"a standard pl022 can only handle "
"1 <= n <= 16 bit words\n");
+ status = -ENOTSUPP;
goto err_config_params;
}
}
@@ -1656,6 +1608,8 @@ static int pl022_setup(struct spi_device *spi)
/* Special setup for the ST micro extended control registers */
if (pl022->vendor->extended_cr) {
+ u32 etx;
+
if (pl022->vendor->pl023) {
/* These bits are only in the PL023 */
SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
@@ -1671,29 +1625,51 @@ static int pl022_setup(struct spi_device *spi)
SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
SSP_CR1_MASK_MWAIT_ST, 6);
}
- SSP_WRITE_BITS(chip->cr0, chip_info->data_size,
+ SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS_ST, 0);
- SSP_WRITE_BITS(chip->cr1, chip_info->endian_rx,
- SSP_CR1_MASK_RENDN_ST, 4);
- SSP_WRITE_BITS(chip->cr1, chip_info->endian_tx,
- SSP_CR1_MASK_TENDN_ST, 5);
+
+ if (spi->mode & SPI_LSB_FIRST) {
+ tmp = SSP_RX_LSB;
+ etx = SSP_TX_LSB;
+ } else {
+ tmp = SSP_RX_MSB;
+ etx = SSP_TX_MSB;
+ }
+ SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
+ SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
SSP_CR1_MASK_RXIFLSEL_ST, 7);
SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
SSP_CR1_MASK_TXIFLSEL_ST, 10);
} else {
- SSP_WRITE_BITS(chip->cr0, chip_info->data_size,
+ SSP_WRITE_BITS(chip->cr0, bits - 1,
SSP_CR0_MASK_DSS, 0);
SSP_WRITE_BITS(chip->cr0, chip_info->iface,
SSP_CR0_MASK_FRF, 4);
}
+
/* Stuff that is common for all versions */
- SSP_WRITE_BITS(chip->cr0, chip_info->clk_pol, SSP_CR0_MASK_SPO, 6);
- SSP_WRITE_BITS(chip->cr0, chip_info->clk_phase, SSP_CR0_MASK_SPH, 7);
+ if (spi->mode & SPI_CPOL)
+ tmp = SSP_CLK_POL_IDLE_HIGH;
+ else
+ tmp = SSP_CLK_POL_IDLE_LOW;
+ SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
+
+ if (spi->mode & SPI_CPHA)
+ tmp = SSP_CLK_SECOND_EDGE;
+ else
+ tmp = SSP_CLK_FIRST_EDGE;
+ SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 6);
+
SSP_WRITE_BITS(chip->cr0, chip_info->clk_freq.scr, SSP_CR0_MASK_SCR, 8);
/* Loopback is available on all versions except PL023 */
- if (!pl022->vendor->pl023)
- SSP_WRITE_BITS(chip->cr1, chip_info->lbm, SSP_CR1_MASK_LBM, 0);
+ if (!pl022->vendor->pl023) {
+ if (spi->mode & SPI_LOOP)
+ tmp = LOOPBACK_ENABLED;
+ else
+ tmp = LOOPBACK_DISABLED;
+ SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
+ }
SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable,
SSP_CR1_MASK_SOD, 3);
@@ -1702,6 +1678,7 @@ static int pl022_setup(struct spi_device *spi)
spi_set_ctldata(spi, chip);
return status;
err_config_params:
+ spi_set_ctldata(spi, NULL);
err_first_setup:
kfree(chip);
return status;
@@ -1764,6 +1741,14 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
master->setup = pl022_setup;
master->transfer = pl022_transfer;
+ /*
+ * Supports mode 0-3, loopback, and active low CS. Transfers are
+ * always MS bit first on the original pl022.
+ */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
+ if (pl022->vendor->extended_cr)
+ master->mode_bits |= SPI_LSB_FIRST;
+
dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
status = amba_request_regions(adev, NULL);
--
1.7.2.2
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