[U-Boot] FSL eSPI driver is a mess, hack attached.

[Joakim Tjernlund]

The fsl_espi.c is wreck w.r.t large TX data.
Below is what I had to hack to load a FPGA over SPI and
what is the malloc hack good for? This does not work
well for TXing several MB data.

The driver needs to be rewritten and I do not have the
time so I post what I got in the hope it can help someone
else or trigger a rewrite.

---
 drivers/spi/fsl_espi.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/fsl_espi.c b/drivers/spi/fsl_espi.c
index 7c84582..2843a8e 100644
--- a/drivers/spi/fsl_espi.c
+++ b/drivers/spi/fsl_espi.c
@@ -28,8 +28,9 @@ struct fsl_spi_slave {
 
 #define ESPI_MAX_CS_NUM		4
 
-#define ESPI_EV_RNE		(1 << 9)
-#define ESPI_EV_TNF		(1 << 8)
+#define ESPI_EV_DON		(1 << (31 - 17))
+#define ESPI_EV_RNE		(1 << (31 - 22))
+#define ESPI_EV_TNF		(1 << (31 - 23))
 
 #define ESPI_MODE_EN		(1 << 31)	/* Enable interface */
 #define ESPI_MODE_TXTHR(x)	((x) << 8)	/* Tx FIFO threshold */
@@ -37,6 +38,8 @@ struct fsl_spi_slave {
 
 #define ESPI_COM_CS(x)		((x) << 30)
 #define ESPI_COM_TRANLEN(x)	((x) << 0)
+#define ESPI_COM_TO             (1 << (31 - 4))
+
 
 #define ESPI_CSMODE_CI_INACTIVEHIGH	(1 << 31)
 #define ESPI_CSMODE_CP_BEGIN_EDGCLK	(1 << 30)
@@ -146,8 +149,9 @@ int spi_claim_bus(struct spi_slave *slave)
 			| ESPI_CSMODE_CI_INACTIVEHIGH);
 
 	/* Character bit order: msb first */
-	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
-		| ESPI_CSMODE_REV_MSB_FIRST);
+	if (!(mode & SPI_LSB_FIRST))
+		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
+			 | ESPI_CSMODE_REV_MSB_FIRST);
 
 	/* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
@@ -172,7 +176,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
 	int len = 0;
 	int num_blks, num_chunks, max_tran_len, tran_len;
 	int num_bytes;
-	unsigned char *ch;
+	//unsigned char *ch;
 	unsigned char *buffer = NULL;
 	size_t buf_len;
 	u8 *cmd_buf = fsl->cmd_buf;
@@ -216,20 +220,21 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
 		cmd_len = 0;
 		break;
 	}
-
+	dout = data_out;
 	debug("spi_xfer: slave %u:%u dout %08X(%p) din %08X(%p) len %u\n",
 	      slave->bus, slave->cs, *(uint *) dout,
 	      dout, *(uint *) din, din, len);
 
 	num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
+	dout = buffer;
 	while (num_chunks--) {
 		if (data_in)
 			din = buffer + rx_offset;
-		dout = buffer;
 		tran_len = min(data_len , max_tran_len);
 		num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
 		num_bytes = (tran_len + cmd_len) % 4;
 		fsl->data_len = tran_len + cmd_len;
+		data_len -= tran_len;
 		spi_cs_activate(slave);
 
 		/* Clear all eSPI events */
@@ -253,11 +258,12 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
 			}
 
 			/* Wait for eSPI transmit to get out */
-			udelay(80);
+			udelay(5);
 
 			event = in_be32(&espi->event);
 			if (event & ESPI_EV_RNE) {
 				tmpdin = in_be32(&espi->rx);
+#if 0
 				if (num_blks == 0 && num_bytes != 0) {
 					ch = (unsigned char *)&tmpdin;
 					while (num_bytes--)
@@ -266,7 +272,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
 					*(u32 *) din = tmpdin;
 					din += 4;
 				}
-
+#endif
 				out_be32(&espi->event, in_be32(&espi->event)
 						| ESPI_EV_RNE);
 				debug("***spi_xfer:...%08x readed\n", tmpdin);
@@ -301,6 +307,7 @@ void spi_cs_activate(struct spi_slave *slave)
 
 	com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
 	com |= ESPI_COM_CS(slave->cs);
+	com |= ESPI_COM_TO;
 	com |= ESPI_COM_TRANLEN(data_len - 1);
 	out_be32(&espi->com, com);
 }
-- 
1.8.3.2