From 1b7f99bd6b52e3fd03653dca80af3faf6e7e8852 Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Wed, 5 Jun 2019 16:34:01 -0700 Subject: spi_flash: Make .read() callback optional All SPI flash chip drivers currently in coreboot use the generic read functions (spi_flash_cmd_read_fast()/_slow()) as their read callback. The only use case for specialized read callbacks we have left is with specialized flash controllers like Intel fast_spi (which sort of impersonate the flash chip driver by implementing their own probe function). This patch unifies the behavior for all normal flash drivers by making the read callback optional and letting them all fall back to a default read implementation that handles normal fast/slow reading. Most of the drivers used to install the respective callback after checking CONFIG_SPI_FLASH_NO_FAST_READ, but some hardcoded either slow or fast writes. I have found no indications for why this is and spot-checked datasheets for affected vendors to make sure they all support both commands, so I assume this is just some old inaccuracy rather than important differences that need preserving. (Please yell if you disagree.) Also take the opportunity to refactor some of the common spi_flash.c code a bit because I felt there are too many nested functions that don't really do enough on their own, and centralizing stuff a bit should make it easier to follow the code flow. (Some of this is in preparation for the next patch.) Change-Id: I2096a3ce619767b41b1b0c0c2b8e95b2bd90a419 Signed-off-by: Julius Werner Reviewed-on: https://review.coreboot.org/c/coreboot/+/33282 Tested-by: build bot (Jenkins) Reviewed-by: Arthur Heymans Reviewed-by: Furquan Shaikh Reviewed-by: Aaron Durbin --- src/drivers/spi/spi_flash.c | 97 ++++++++++++++++----------------------------- 1 file changed, 35 insertions(+), 62 deletions(-) (limited to 'src/drivers/spi/spi_flash.c') diff --git a/src/drivers/spi/spi_flash.c b/src/drivers/spi/spi_flash.c index ae1d2efb22..5e42a375f6 100644 --- a/src/drivers/spi/spi_flash.c +++ b/src/drivers/spi/spi_flash.c @@ -31,7 +31,7 @@ static void spi_flash_addr(u32 addr, u8 *cmd) static int do_spi_flash_cmd(const struct spi_slave *spi, const void *dout, size_t bytes_out, void *din, size_t bytes_in) { - int ret = 1; + int ret; /* * SPI flash requires command-response kind of behavior. Thus, two * separate SPI vectors are required -- first to transmit dout and other @@ -49,11 +49,11 @@ static int do_spi_flash_cmd(const struct spi_slave *spi, const void *dout, if (!bytes_in) count = 1; - if (spi_claim_bus(spi)) + ret = spi_claim_bus(spi); + if (ret) return ret; - if (spi_xfer_vector(spi, vectors, count) == 0) - ret = 0; + ret = spi_xfer_vector(spi, vectors, count); spi_release_bus(spi); return ret; @@ -68,18 +68,6 @@ int spi_flash_cmd(const struct spi_slave *spi, u8 cmd, void *response, size_t le return ret; } -static int spi_flash_cmd_read(const struct spi_slave *spi, const u8 *cmd, - size_t cmd_len, void *data, size_t data_len) -{ - int ret = do_spi_flash_cmd(spi, cmd, cmd_len, data, data_len); - if (ret) { - printk(BIOS_WARNING, "SF: Failed to send read command (%zu bytes): %d\n", - data_len, ret); - } - - return ret; -} - /* TODO: This code is quite possibly broken and overflowing stacks. Fix ASAP! */ #pragma GCC diagnostic push #if defined(__GNUC__) && !defined(__clang__) @@ -103,34 +91,38 @@ int spi_flash_cmd_write(const struct spi_slave *spi, const u8 *cmd, } #pragma GCC diagnostic pop -static int spi_flash_cmd_read_array(const struct spi_slave *spi, u8 *cmd, - size_t cmd_len, u32 offset, - size_t len, void *data) -{ - spi_flash_addr(offset, cmd); - return spi_flash_cmd_read(spi, cmd, cmd_len, data, len); -} - /* Perform the read operation honoring spi controller fifo size, reissuing * the read command until the full request completed. */ -static int spi_flash_cmd_read_array_wrapped(const struct spi_slave *spi, - u8 *cmd, size_t cmd_len, u32 offset, - size_t len, void *buf) +static int spi_flash_read_chunked(const struct spi_flash *flash, u32 offset, + size_t len, void *buf) { - int ret; - size_t xfer_len; - uint8_t *data = buf; + u8 cmd[5]; + int ret, cmd_len; + int (*do_cmd)(const struct spi_slave *spi, const void *din, + size_t in_bytes, void *out, size_t out_bytes); + + if (CONFIG(SPI_FLASH_NO_FAST_READ)) { + cmd_len = 4; + cmd[0] = CMD_READ_ARRAY_SLOW; + do_cmd = do_spi_flash_cmd; + } else { + cmd_len = 5; + cmd[0] = CMD_READ_ARRAY_FAST; + cmd[4] = 0; + do_cmd = do_spi_flash_cmd; + } + uint8_t *data = buf; while (len) { - xfer_len = spi_crop_chunk(spi, cmd_len, len); - - /* Perform the read. */ - ret = spi_flash_cmd_read_array(spi, cmd, cmd_len, - offset, xfer_len, data); - - if (ret) + size_t xfer_len = spi_crop_chunk(&flash->spi, cmd_len, len); + spi_flash_addr(offset, cmd); + ret = do_cmd(&flash->spi, cmd, cmd_len, data, xfer_len); + if (ret) { + printk(BIOS_WARNING, + "SF: Failed to send read command %#.2x(%#x, %#zx): %d\n", + cmd[0], offset, xfer_len, ret); return ret; - + } offset += xfer_len; data += xfer_len; len -= xfer_len; @@ -139,28 +131,6 @@ static int spi_flash_cmd_read_array_wrapped(const struct spi_slave *spi, return 0; } -int spi_flash_cmd_read_fast(const struct spi_flash *flash, u32 offset, - size_t len, void *data) -{ - u8 cmd[5]; - - cmd[0] = CMD_READ_ARRAY_FAST; - cmd[4] = 0x00; - - return spi_flash_cmd_read_array_wrapped(&flash->spi, cmd, sizeof(cmd), - offset, len, data); -} - -int spi_flash_cmd_read_slow(const struct spi_flash *flash, u32 offset, - size_t len, void *data) -{ - u8 cmd[4]; - - cmd[0] = CMD_READ_ARRAY_SLOW; - return spi_flash_cmd_read_array_wrapped(&flash->spi, cmd, sizeof(cmd), - offset, len, data); -} - int spi_flash_cmd_poll_bit(const struct spi_flash *flash, unsigned long timeout, u8 cmd, u8 poll_bit) { @@ -174,7 +144,7 @@ int spi_flash_cmd_poll_bit(const struct spi_flash *flash, unsigned long timeout, mono_time_add_msecs(&end, timeout); do { - ret = spi_flash_cmd_read(spi, &cmd, 1, &status, 1); + ret = do_spi_flash_cmd(spi, &cmd, 1, &status, 1); if (ret) return -1; if ((status & poll_bit) == 0) @@ -391,7 +361,10 @@ int spi_flash_probe(unsigned int bus, unsigned int cs, struct spi_flash *flash) int spi_flash_read(const struct spi_flash *flash, u32 offset, size_t len, void *buf) { - return flash->ops->read(flash, offset, len, buf); + if (flash->ops->read) + return flash->ops->read(flash, offset, len, buf); + + return spi_flash_read_chunked(flash, offset, len, buf); } int spi_flash_write(const struct spi_flash *flash, u32 offset, size_t len, -- cgit v1.2.3