fix console change race exposed by CFS
[pandora-kernel.git] / drivers / spi / spi_mpc83xx.c
index e9798bf..32cda77 100644 (file)
@@ -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),