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path: root/drivers/spi/spi_mpc83xx.c
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Diffstat (limited to 'drivers/spi/spi_mpc83xx.c')
-rw-r--r--drivers/spi/spi_mpc83xx.c102
1 files changed, 86 insertions, 16 deletions
diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
index e9798bf7b8c6..32cda77b31cd 100644
--- a/drivers/spi/spi_mpc83xx.c
+++ b/drivers/spi/spi_mpc83xx.c
@@ -39,6 +39,7 @@ struct mpc83xx_spi_reg {
};
/* SPI Controller mode register definitions */
+#define SPMODE_LOOP (1 << 30)
#define SPMODE_CI_INACTIVEHIGH (1 << 29)
#define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
#define SPMODE_DIV16 (1 << 27)
@@ -47,6 +48,7 @@ struct mpc83xx_spi_reg {
#define SPMODE_ENABLE (1 << 24)
#define SPMODE_LEN(x) ((x) << 20)
#define SPMODE_PM(x) ((x) << 16)
+#define SPMODE_OP (1 << 14)
/*
* Default for SPI Mode:
@@ -84,7 +86,12 @@ struct mpc83xx_spi {
unsigned nsecs; /* (clock cycle time)/2 */
- u32 sysclk;
+ u32 spibrg; /* SPIBRG input clock */
+ u32 rx_shift; /* RX data reg shift when in qe mode */
+ u32 tx_shift; /* TX data reg shift when in qe mode */
+
+ bool qe_mode;
+
void (*activate_cs) (u8 cs, u8 polarity);
void (*deactivate_cs) (u8 cs, u8 polarity);
};
@@ -103,7 +110,7 @@ static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
{ \
type * rx = mpc83xx_spi->rx; \
- *rx++ = (type)data; \
+ *rx++ = (type)(data >> mpc83xx_spi->rx_shift); \
mpc83xx_spi->rx = rx; \
}
@@ -114,7 +121,7 @@ u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi) \
const type * tx = mpc83xx_spi->tx; \
if (!tx) \
return 0; \
- data = *tx++; \
+ data = *tx++ << mpc83xx_spi->tx_shift; \
mpc83xx_spi->tx = tx; \
return data; \
}
@@ -141,29 +148,48 @@ static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
if (value == BITBANG_CS_ACTIVE) {
u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
u32 len = spi->bits_per_word;
+ u8 pm;
+
if (len == 32)
len = 0;
else
len = len - 1;
/* mask out bits we are going to set */
- regval &= ~0x38ff0000;
+ regval &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
+ | SPMODE_LEN(0xF) | SPMODE_DIV16
+ | SPMODE_PM(0xF) | SPMODE_REV | SPMODE_LOOP);
if (spi->mode & SPI_CPHA)
regval |= SPMODE_CP_BEGIN_EDGECLK;
if (spi->mode & SPI_CPOL)
regval |= SPMODE_CI_INACTIVEHIGH;
+ if (!(spi->mode & SPI_LSB_FIRST))
+ regval |= SPMODE_REV;
+ if (spi->mode & SPI_LOOP)
+ regval |= SPMODE_LOOP;
regval |= SPMODE_LEN(len);
- if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) {
- u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64);
+ if ((mpc83xx_spi->spibrg / spi->max_speed_hz) >= 64) {
+ pm = mpc83xx_spi->spibrg / (spi->max_speed_hz * 64) - 1;
+ if (pm > 0x0f) {
+ dev_err(&spi->dev, "Requested speed is too "
+ "low: %d Hz. Will use %d Hz instead.\n",
+ spi->max_speed_hz,
+ mpc83xx_spi->spibrg / 1024);
+ pm = 0x0f;
+ }
regval |= SPMODE_PM(pm) | SPMODE_DIV16;
} else {
- u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
+ pm = mpc83xx_spi->spibrg / (spi->max_speed_hz * 4);
+ if (pm)
+ pm--;
regval |= SPMODE_PM(pm);
}
+ /* Turn off SPI unit prior changing mode */
+ mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
if (mpc83xx_spi->activate_cs)
mpc83xx_spi->activate_cs(spi->chip_select, pol);
@@ -197,18 +223,36 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
|| ((bits_per_word > 16) && (bits_per_word != 32)))
return -EINVAL;
+ mpc83xx_spi->rx_shift = 0;
+ mpc83xx_spi->tx_shift = 0;
if (bits_per_word <= 8) {
mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
+ if (mpc83xx_spi->qe_mode) {
+ mpc83xx_spi->rx_shift = 16;
+ mpc83xx_spi->tx_shift = 24;
+ }
} else if (bits_per_word <= 16) {
mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
+ if (mpc83xx_spi->qe_mode) {
+ mpc83xx_spi->rx_shift = 16;
+ mpc83xx_spi->tx_shift = 16;
+ }
} else if (bits_per_word <= 32) {
mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
} else
return -EINVAL;
+ if (mpc83xx_spi->qe_mode && spi->mode & SPI_LSB_FIRST) {
+ mpc83xx_spi->tx_shift = 0;
+ if (bits_per_word <= 8)
+ mpc83xx_spi->rx_shift = 8;
+ else
+ mpc83xx_spi->rx_shift = 0;
+ }
+
/* nsecs = (clock period)/2 */
if (!hz)
hz = spi->max_speed_hz;
@@ -223,21 +267,35 @@ int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
- /* Mask out bits_per_wordgth */
- regval &= 0xff0fffff;
+ /* mask out bits we are going to set */
+ regval &= ~(SPMODE_LEN(0xF) | SPMODE_REV);
regval |= SPMODE_LEN(bits_per_word);
+ if (!(spi->mode & SPI_LSB_FIRST))
+ regval |= SPMODE_REV;
+ /* Turn off SPI unit prior changing mode */
+ mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
return 0;
}
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
+ | SPI_LSB_FIRST | SPI_LOOP)
+
static int mpc83xx_spi_setup(struct spi_device *spi)
{
struct spi_bitbang *bitbang;
struct mpc83xx_spi *mpc83xx_spi;
int retval;
+ if (spi->mode & ~MODEBITS) {
+ dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
+ spi->mode & ~MODEBITS);
+ return -EINVAL;
+ }
+
if (!spi->max_speed_hz)
return -EINVAL;
@@ -326,11 +384,8 @@ irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
mpc83xx_spi->count -= 1;
if (mpc83xx_spi->count) {
- if (mpc83xx_spi->tx) {
- u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
- mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
- word);
- }
+ u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
+ mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
} else {
complete(&mpc83xx_spi->done);
}
@@ -371,18 +426,29 @@ static int __init mpc83xx_spi_probe(struct platform_device *dev)
ret = -ENODEV;
goto free_master;
}
-
mpc83xx_spi = spi_master_get_devdata(master);
mpc83xx_spi->bitbang.master = spi_master_get(master);
mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
- mpc83xx_spi->sysclk = pdata->sysclk;
mpc83xx_spi->activate_cs = pdata->activate_cs;
mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
+ mpc83xx_spi->qe_mode = pdata->qe_mode;
mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
+ if (mpc83xx_spi->qe_mode)
+ mpc83xx_spi->spibrg = pdata->sysclk / 2;
+ else
+ mpc83xx_spi->spibrg = pdata->sysclk;
+
+ mpc83xx_spi->rx_shift = 0;
+ mpc83xx_spi->tx_shift = 0;
+ if (mpc83xx_spi->qe_mode) {
+ mpc83xx_spi->rx_shift = 16;
+ mpc83xx_spi->tx_shift = 24;
+ }
+
mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
init_completion(&mpc83xx_spi->done);
@@ -417,6 +483,9 @@ static int __init mpc83xx_spi_probe(struct platform_device *dev)
/* Enable SPI interface */
regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
+ if (pdata->qe_mode)
+ regval |= SPMODE_OP;
+
mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
ret = spi_bitbang_start(&mpc83xx_spi->bitbang);
@@ -458,6 +527,7 @@ static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
return 0;
}
+MODULE_ALIAS("mpc83xx_spi"); /* for platform bus hotplug */
static struct platform_driver mpc83xx_spi_driver = {
.probe = mpc83xx_spi_probe,
.remove = __devexit_p(mpc83xx_spi_remove),
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-23 10:14:02 +0000