New patch to review for coreboot: Skylake: Implement HW Sequence based WP status read functionality

[Patrick Georgi]

Patrick Georgi ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/11423

-gerrit

commit 8aca3e5298ad119aa9267b6221c05e98531a2cea
Author: Barnali Sarkar 
Date:   Wed Aug 19 14:15:32 2015 +0530

Skylake: Implement HW Sequence based WP status read functionality

Early(romstage) SPI write protected status read(wpsr) functionality
    was broken causing 2 sec timeout issue.Implementing HW Seq based rd
    status operation in romstage.

BRANCH=NONE
    BUG=chrome-os-partner:42115
    TEST=Built for sklrvp and kunimitsu and tested using below command
    flashrom -p host --wp-enable [this should enable WP on flash chip]
    Read using romstage SPI.c. WPSR=0x80 (CB is reading Bit 7 as locked)
    flashrom -p host --wp-disable [this should disable WP on flash chip]
    Read using romstage SPI.c. WPSR=0x00 (CB is reading Bit 7 as unlocked)

Change-Id: I79f6767d88f766be1b47adaf7c6e2fa368750d5a
    Signed-off-by: Patrick Georgi 
    Original-Commit-Id: 4b798c44634581ebf7cdeea76c486e95e1f0a488
    Original-Change-Id: I7e9b02e313b84765ddfef06724e9921550c4e677
    Original-Signed-off-by: Subrata 
    Original-Signed-off-by: Barnali Sarkar 
    Original-Reviewed-on: https://chromium-review.googlesource.com/294445
    Original-Reviewed-by: Aaron Durbin 
---
 src/soc/intel/skylake/romstage/spi.c | 130 +++++------------------------------
 1 file changed, 19 insertions(+), 111 deletions(-)

diff --git a/src/soc/intel/skylake/romstage/spi.c b/src/soc/intel/skylake/romstage/spi.c
index 206350b..be6db41 100644
--- a/src/soc/intel/skylake/romstage/spi.c
+++ b/src/soc/intel/skylake/romstage/spi.c
@@ -18,100 +18,21 @@
  * Foundation, Inc.
  */

-#include <arch/io.h>
-#include <console/console.h>
-#include <delay.h>
-#include <soc/spi.h>
+#include <flash_controller.h>
 #include <soc/romstage.h>

-#define SPI_DELAY 10     /* 10us */
-#define SPI_RETRY 200000 /* 2s */
-
-static int early_spi_read_block(u32 offset, u8 size, u8 *buffer)
-{
-	u32 *ptr32 = (u32 *)buffer;
-	u32 i;
-	u16 hsfs, hsfc;
-	void *spibar = get_spi_bar();
-
-	/* Clear status bits */
-	hsfs = read16(spibar + SPIBAR_HSFS);
-	write16(spibar + SPIBAR_HSFS, hsfs | SPIBAR_HSFS_AEL |
-			SPIBAR_HSFS_FCERR | SPIBAR_HSFS_FDONE);
-
-	if (read16(spibar + SPIBAR_HSFS) & SPIBAR_HSFS_SCIP) {
-		printk(BIOS_ERR, "SPI ERROR: transaction in progress\n");
-		return -1;
-	}
-
-	/* Set flash address */
-	write32(spibar + SPIBAR_FADDR, offset);
-
-	/* Setup read transaction */
-	write16(spibar + SPIBAR_HSFC, SPIBAR_HSFC_BYTE_COUNT(size) |
-			SPIBAR_HSFC_CYCLE_READ);
-
-	/* Start transactinon */
-	hsfc = read16(spibar + SPIBAR_HSFC);
-	write16(spibar + SPIBAR_HSFC, hsfc | SPIBAR_HSFC_GO);
-
-	/* Wait for completion */
-	for (i = 0; i < SPI_RETRY; i++) {
-		if (read16(spibar + SPIBAR_HSFS) & SPIBAR_HSFS_SCIP) {
-			/* Cycle in progress, wait 1ms */
-			udelay(SPI_DELAY);
-			continue;
-		}
-
-		if (read16(spibar + SPIBAR_HSFS) & SPIBAR_HSFS_AEL) {
-			printk(BIOS_ERR, "SPI ERROR: Access Error\n");
-			return -1;
-
-		}
-
-		if (read16(spibar + SPIBAR_HSFS) & SPIBAR_HSFS_FCERR) {
-			printk(BIOS_ERR, "SPI ERROR: Flash Cycle Error\n");
-			return -1;
-		}
-		break;
-	}
-
-	if (i >= SPI_RETRY) {
-		printk(BIOS_ERR, "SPI ERROR: Timeout\n");
-		return -1;
-	}
-
-	/* Read the data */
-	for (i = 0; i < size; i += sizeof(u32)) {
-		if (size-i >= 4) {
-			/* reading >= dword */
-			*ptr32++ = read32(spibar +
-				SPIBAR_FDATA(i/sizeof(u32)));
-		} else {
-			/* reading < dword */
-			u8 j, *ptr8 = (u8 *)ptr32;
-			u32 temp;
-
-			temp = read32(spibar +
-				SPIBAR_FDATA(i/sizeof(u32)));
-			for (j = 0; j < (size-i); j++) {
-				*ptr8++ = temp & 0xff;
-				temp >>= 8;
-			}
-		}
-	}
-
-	return size;
-}
-
 int early_spi_read(u32 offset, u32 size, u8 *buffer)
 {
    u32 current = 0;

+	spi_init();
    while (size > 0) {
    	u8 count = (size < 64) ? size : 64;
-		if (early_spi_read_block(offset + current, count,
-					 buffer + current) < 0)
+		/* sending NULL for spiflash struct parameter since we are not
+		 * calling HWSEQ read() call via Probe.
+		 */
+		if (pch_hwseq_read(NULL, offset + current, count,
+				   buffer + current) != 0)
    		return -1;
    	size -= count;
    	current += count;
@@ -122,37 +43,24 @@ int early_spi_read(u32 offset, u32 size, u8 *buffer)

/*
  * Minimal set of commands to read WPSR from SPI.
- * Don't use this code outside romstage -- it trashes the opmenu table.
  * Returns 0 on success, < 0 on failure.
  */
 int early_spi_read_wpsr(u8 *sr)
 {
-	int retry;
-	void *spibar = get_spi_bar();
-
-	/* No address associated with rdsr */
-	write8(spibar + SPIBAR_OPTYPE, 0x0);
-	/* Setup opcode[0] = read wpsr */
-	write8(spibar + SPIBAR_OPMENU_LOWER, 0x5);
+	uint8_t rdsr;
+	int ret = 0;

-	/* Start transaction */
-	write16(spibar + SPIBAR_SSFC, SPIBAR_SSFC_DATA | SPIBAR_SSFC_GO);
-
-	/* Wait for error / complete status */
-	for (retry = SPI_RETRY; retry; retry--) {
-		u16 status = read16(spibar + SPIBAR_SSFS);
-		if (status & SPIBAR_SSFS_ERROR) {
-			printk(BIOS_ERR, "SPI rdsr failed\n");
-			return -1;
-		} else if (status & SPIBAR_SSFS_DONE) {
-			break;
-		}
+	spi_init();

-		udelay(SPI_DELAY);
-	}
-	/* Flash protected range 0 register bit 31 indicates WP
-	 * Bit 31[WPE] 1= WP Enable 0= WP Disable
+	/* sending NULL for spiflash struct parameter since we are not
+	 * calling HWSEQ read_status() call via Probe.
     */
-	*sr = (read32(spibar + SPIBAR_FPR(0)) & SPIBAR_FPR_WPE) >> 24;
+	ret = pch_hwseq_read_status(NULL, &rdsr);
+	if (ret) {
+		printk(BIOS_ERR, "SPI rdsr failed\n");
+		return ret;
+	}
+	*sr = rdsr & WPSR_MASK_SRP0_BIT;
+
    return 0;
 }