spi25_statusreg: make register read/write functions generic
This patch adds new spi_{read,write}_register() functions that take the
source/destination register as an argument. Currently they can only
access SR1, support for other registers will be added in another patch.
Since we're refactoring things, this commit also makes
spi_read_register() return an error code, making it possible to identify
error conditions that spi_read_status_register() concealed.
This also removes the initial 100ms delay between writing a register and
the first attempt to check the chip's status. An initial delay was added
to avoid needing to read the status register multiple times, but that is
unlikely to cause problems on modern flash chips.
Tested: flashrom -{r,w,E}
Tested: flashrom --wp-{enable,disable,range,list,status} at end of patch series
Change-Id: I0a3951bbf993f2d8d830143b29d3ce16cc6901d7
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/58475
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Original-Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
Original-Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/70964
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/spi25_statusreg.c b/spi25_statusreg.c
index a0b0fcf..0d7bc25 100644
--- a/spi25_statusreg.c
+++ b/spi25_statusreg.c
@@ -22,24 +22,23 @@
#include "spi.h"
/* === Generic functions === */
-static int spi_write_status_register_flag(const struct flashctx *flash, int status, const unsigned char enable_opcode)
+static int spi_write_register_flag(const struct flashctx *flash, uint8_t enable_opcode, uint8_t *write_cmd, size_t write_cmd_len, enum flash_reg reg)
{
- int result;
- int i = 0;
/*
- * WRSR requires either EWSR or WREN depending on chip type.
- * The code below relies on the fact hat EWSR and WREN have the same
- * INSIZE and OUTSIZE.
+ * Enabling register writes requires either EWSR or WREN depending on
+ * chip type. The code below relies on the fact hat EWSR and WREN have
+ * the same INSIZE and OUTSIZE.
*/
+
struct spi_command cmds[] = {
{
.writecnt = JEDEC_WREN_OUTSIZE,
- .writearr = (const unsigned char[]){ enable_opcode },
+ .writearr = &enable_opcode,
.readcnt = 0,
.readarr = NULL,
}, {
- .writecnt = JEDEC_WRSR_OUTSIZE,
- .writearr = (const unsigned char[]){ JEDEC_WRSR, (unsigned char) status },
+ .writecnt = write_cmd_len,
+ .writearr = write_cmd,
.readcnt = 0,
.readarr = NULL,
}, {
@@ -49,69 +48,117 @@
.readarr = NULL,
}};
- result = spi_send_multicommand(flash, cmds);
+ int result = spi_send_multicommand(flash, cmds);
if (result) {
msg_cerr("%s failed during command execution\n", __func__);
- /* No point in waiting for the command to complete if execution
+ /*
+ * No point in waiting for the command to complete if execution
* failed.
*/
return result;
}
- /* WRSR performs a self-timed erase before the changes take effect.
+
+ /*
+ * WRSR performs a self-timed erase before the changes take effect.
* This may take 50-85 ms in most cases, and some chips apparently
* allow running RDSR only once. Therefore pick an initial delay of
* 100 ms, then wait in 10 ms steps until a total of 5 s have elapsed.
+ *
+ * Newer chips with multiple status registers (SR2 etc.) are unlikely
+ * to have problems with multiple RDSR commands, so only wait for the
+ * initial 100 ms if the register we wrote to was SR1.
*/
- programmer_delay(100 * 1000);
- while (spi_read_status_register(flash) & SPI_SR_WIP) {
- if (++i > 490) {
- msg_cerr("Error: WIP bit after WRSR never cleared\n");
- return TIMEOUT_ERROR;
- }
+ int delay_ms = 5000;
+ if (reg == STATUS1) {
+ programmer_delay(100 * 1000);
+ delay_ms -= 100;
+ }
+
+ for (; delay_ms > 0; delay_ms -= 10) {
+ if ((spi_read_status_register(flash) & SPI_SR_WIP) == 0)
+ return 0;
programmer_delay(10 * 1000);
}
- return 0;
+
+ msg_cerr("Error: WIP bit after WRSR never cleared\n");
+ return TIMEOUT_ERROR;
}
-int spi_write_status_register(const struct flashctx *flash, int status)
+int spi_write_register(const struct flashctx *flash, enum flash_reg reg, uint8_t value)
{
int feature_bits = flash->chip->feature_bits;
- int ret = 1;
+
+ uint8_t write_cmd[3];
+ size_t write_cmd_len = 0;
+
+ /*
+ * Create SPI write command sequence based on the destination register
+ * and the chip's supported command set.
+ */
+ switch (reg) {
+ case STATUS1:
+ write_cmd[0] = JEDEC_WRSR;
+ write_cmd[1] = value;
+ write_cmd_len = JEDEC_WRSR_OUTSIZE;
+ break;
+ default:
+ msg_cerr("Cannot write register: unknown register\n");
+ return 1;
+ }
if (!(feature_bits & (FEATURE_WRSR_WREN | FEATURE_WRSR_EWSR))) {
msg_cdbg("Missing status register write definition, assuming "
"EWSR is needed\n");
feature_bits |= FEATURE_WRSR_EWSR;
}
+
+ int ret = 1;
if (feature_bits & FEATURE_WRSR_WREN)
- ret = spi_write_status_register_flag(flash, status, JEDEC_WREN);
+ ret = spi_write_register_flag(flash, JEDEC_WREN, write_cmd, write_cmd_len, reg);
if (ret && (feature_bits & FEATURE_WRSR_EWSR))
- ret = spi_write_status_register_flag(flash, status, JEDEC_EWSR);
+ ret = spi_write_register_flag(flash, JEDEC_EWSR, write_cmd, write_cmd_len, reg);
return ret;
}
+int spi_read_register(const struct flashctx *flash, enum flash_reg reg, uint8_t *value)
+{
+ uint8_t read_cmd;
+
+ switch (reg) {
+ case STATUS1:
+ read_cmd = JEDEC_RDSR;
+ break;
+ default:
+ msg_cerr("Cannot read register: unknown register\n");
+ return 1;
+ }
+
+ /* FIXME: No workarounds for driver/hardware bugs in generic code. */
+ /* JEDEC_RDSR_INSIZE=1 but wbsio needs 2 */
+ uint8_t readarr[2];
+
+ int ret = spi_send_command(flash, sizeof(read_cmd), sizeof(readarr), &read_cmd, readarr);
+ if (ret) {
+ msg_cerr("Register read failed!\n");
+ return ret;
+ }
+
+ *value = readarr[0];
+ return 0;
+}
+
uint8_t spi_read_status_register(const struct flashctx *flash)
{
- static const unsigned char cmd[JEDEC_RDSR_OUTSIZE] = { JEDEC_RDSR };
- /* FIXME: No workarounds for driver/hardware bugs in generic code. */
- unsigned char readarr[2]; /* JEDEC_RDSR_INSIZE=1 but wbsio needs 2 */
- int ret;
-
- /* Read Status Register */
- ret = spi_send_command(flash, sizeof(cmd), sizeof(readarr), cmd, readarr);
- if (ret) {
- msg_cerr("RDSR failed!\n");
- /* FIXME: We should propagate the error. */
- return 0;
- }
-
- return readarr[0];
+ uint8_t status = 0;
+ /* FIXME: We should propagate the error. */
+ spi_read_register(flash, STATUS1, &status);
+ return status;
}
static int spi_restore_status(struct flashctx *flash, uint8_t status)
{
msg_cdbg("restoring chip status (0x%02x)\n", status);
- return spi_write_status_register(flash, status);
+ return spi_write_register(flash, STATUS1, status);
}
/* A generic block protection disable.
@@ -156,9 +203,9 @@
return 1;
}
/* All bits except the register lock bit (often called SPRL, SRWD, WPEN) are readonly. */
- result = spi_write_status_register(flash, status & ~lock_mask);
+ result = spi_write_register(flash, STATUS1, status & ~lock_mask);
if (result) {
- msg_cerr("spi_write_status_register failed.\n");
+ msg_cerr("Could not write status register 1.\n");
return result;
}
status = spi_read_status_register(flash);
@@ -169,9 +216,9 @@
msg_cdbg("done.\n");
}
/* Global unprotect. Make sure to mask the register lock bit as well. */
- result = spi_write_status_register(flash, status & ~(bp_mask | lock_mask) & unprotect_mask);
+ result = spi_write_register(flash, STATUS1, status & ~(bp_mask | lock_mask) & unprotect_mask);
if (result) {
- msg_cerr("spi_write_status_register failed.\n");
+ msg_cerr("Could not write status register 1.\n");
return result;
}
status = spi_read_status_register(flash);