[U-Boot] [PATCH 1/9 v4] i.MX31: fix SPI driver for shorter than 32 bit

Anatolij Gustschin
2009-02-06T23:09:12Z

From: Guennadi Liakhovetski <lg@denx.de>

Fix setting the SPI Control register, 8 and 16-bit transfers
and a wrong pointer in the free routine in the mxc_spi driver.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
---

Changes since v1: chose a simpler fix
Changes since v2: fix the simpler fix: v2 worked as long as I just
resetted the board, powering the board down showed, that v2 wasn't
sufficient, it has lost the SPI Control register fix from v1.
Changes since v3: add empty line in spi_free_slave()

I'm going to push it via video tree as Jean-Christophe
mean it is more video related patch and have no objection.

Anatolij

drivers/spi/mxc_spi.c | 31 ++++++++++++++++++++-----------
1 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
index 5957ada..0ac4e90 100644
--- a/drivers/spi/mxc_spi.c
+++ b/drivers/spi/mxc_spi.c
@@ -90,17 +90,15 @@ static u32 spi_xchg_single(struct spi_slave *slave, u32 data, int bitlen)
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
unsigned int cfg_reg = reg_read(mxcs->base + MXC_CSPICTRL);

- if (MXC_CSPICTRL_BITCOUNT(bitlen - 1) != (cfg_reg & MXC_CSPICTRL_BITCOUNT(31))) {
- cfg_reg = (cfg_reg & ~MXC_CSPICTRL_BITCOUNT(31)) |
- MXC_CSPICTRL_BITCOUNT(bitlen - 1);
- reg_write(mxcs->base + MXC_CSPICTRL, cfg_reg);
- }
+ mxcs->ctrl_reg = (mxcs->ctrl_reg & ~MXC_CSPICTRL_BITCOUNT(31)) |
+ MXC_CSPICTRL_BITCOUNT(bitlen - 1);

- reg_write(mxcs->base + MXC_CSPITXDATA, data);
+ if (cfg_reg != mxcs->ctrl_reg)
+ reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg);

- cfg_reg |= MXC_CSPICTRL_XCH;
+ reg_write(mxcs->base + MXC_CSPITXDATA, data);

- reg_write(mxcs->base + MXC_CSPICTRL, cfg_reg);
+ reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg | MXC_CSPICTRL_XCH);

while (reg_read(mxcs->base + MXC_CSPICTRL) & MXC_CSPICTRL_XCH)
;
@@ -122,8 +120,17 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,

for (i = 0, in_l = (u32 *)din, out_l = (u32 *)dout;
i < n_blks;
- i++, in_l++, out_l++, bitlen -= 32)
- *in_l = spi_xchg_single(slave, *out_l, bitlen);
+ i++, in_l++, out_l++, bitlen -= 32) {
+ u32 data = spi_xchg_single(slave, *out_l, bitlen);
+
+ /* Check if we're only transfering 8 or 16 bits */
+ if (!i) {
+ if (bitlen < 9)
+ *(u8 *)din = data;
+ else if (bitlen < 17)
+ *(u16 *)din = data;
+ }
+ }

return 0;
}
@@ -169,7 +176,9 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,

void spi_free_slave(struct spi_slave *slave)
{
- free(slave);
+ struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
+
+ free(mxcs);
}

int spi_claim_bus(struct spi_slave *slave)
--
1.5.3.3