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authorLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 10:56:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-18 10:56:02 -0700
commitb061c59c27e0385e53c961d9fbd18c1c078d9823 (patch)
tree56240ef8e98e9e4712ee58aa8e6e3d51f6ab001f /drivers/spi/omap2_mcspi.c
parent99f4065bac7b8c3f829334b4218a5c2e68cbe440 (diff)
parent568a60eda2e90a11bb3d7f8ef3f6800e9b60d4e5 (diff)
Merge branch 'spi/next' of git://git.secretlab.ca/git/linux-2.6
* 'spi/next' of git://git.secretlab.ca/git/linux-2.6: (34 commits) spi/dw_spi: move dw_spi.h into drivers/spi spi/dw_spi: Fix missing header gpio/langwell: Clear edge bit before handling gpio/langwell: Simplify demux loop gpio/langwell: Convert irq name space gpio/langwell: Fix broken irq_eoi change. gpio; Make Intel chipset gpio drivers depend on x86 gpio/cs5535-gpio: Fix section mismatch spi/rtc-{ds1390,ds3234,m41t94}: Use spi_get_drvdata() for SPI devices spi/davinci: Support DMA transfers larger than 65535 words spi/davinci: Use correct length parameter to dma_map_single calls gpio: Use __devexit at necessary places gpio: add MODULE_DEVICE_TABLE to pch_gpio and ml_ioh_gpio gpio/mcp23s08: support mcp23s17 variant of_mmc_spi: add card detect irq support spi/omap_mcspi: catch xfers of non-multiple SPI word size spi/omap_mcspi: Off-by-one error in finding the right divisor gpio/pca953x: Fix wrong pointer type spi/pl022: rid dangling labels spi: add support for SuperH SPI ...
Diffstat (limited to 'drivers/spi/omap2_mcspi.c')
-rw-r--r--drivers/spi/omap2_mcspi.c38
1 files changed, 24 insertions, 14 deletions
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c
index 36501adc125d..3a5ed06d3d2f 100644
--- a/drivers/spi/omap2_mcspi.c
+++ b/drivers/spi/omap2_mcspi.c
@@ -467,6 +467,9 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
rx_reg = base + OMAP2_MCSPI_RX0;
chstat_reg = base + OMAP2_MCSPI_CHSTAT0;
+ if (c < (word_len>>3))
+ return 0;
+
if (word_len <= 8) {
u8 *rx;
const u8 *tx;
@@ -514,7 +517,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
dev_vdbg(&spi->dev, "read-%d %02x\n",
word_len, *(rx - 1));
}
- } while (c);
+ } while (c > (word_len>>3));
} else if (word_len <= 16) {
u16 *rx;
const u16 *tx;
@@ -561,7 +564,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
dev_vdbg(&spi->dev, "read-%d %04x\n",
word_len, *(rx - 1));
}
- } while (c);
+ } while (c > (word_len>>3));
} else if (word_len <= 32) {
u32 *rx;
const u32 *tx;
@@ -608,7 +611,7 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
dev_vdbg(&spi->dev, "read-%d %08x\n",
word_len, *(rx - 1));
}
- } while (c);
+ } while (c > (word_len>>3));
}
/* for TX_ONLY mode, be sure all words have shifted out */
@@ -631,6 +634,17 @@ out:
return count - c;
}
+static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
+{
+ u32 div;
+
+ for (div = 0; div < 15; div++)
+ if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
+ return div;
+
+ return 15;
+}
+
/* called only when no transfer is active to this device */
static int omap2_mcspi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
@@ -653,12 +667,8 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
if (t && t->speed_hz)
speed_hz = t->speed_hz;
- if (speed_hz) {
- while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
- > speed_hz)
- div++;
- } else
- div = 15;
+ speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
+ div = omap2_mcspi_calc_divisor(speed_hz);
l = mcspi_cached_chconf0(spi);
@@ -695,7 +705,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
mcspi_write_chconf0(spi, l);
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
- OMAP2_MCSPI_MAX_FREQ / (1 << div),
+ OMAP2_MCSPI_MAX_FREQ >> div,
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
(spi->mode & SPI_CPOL) ? "inverted" : "normal");
@@ -996,10 +1006,10 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
t->bits_per_word);
return -EINVAL;
}
- if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
- dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
- t->speed_hz,
- OMAP2_MCSPI_MAX_FREQ/(1<<16));
+ if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
+ dev_dbg(&spi->dev, "speed_hz %d below minimum %d Hz\n",
+ t->speed_hz,
+ OMAP2_MCSPI_MAX_FREQ >> 15);
return -EINVAL;
}