From aaa21d3ffc023623a3a8247e5fa25d0db2bfb630 Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Wed, 24 Jan 2018 10:44:07 +0530 Subject: [PATCH] spi: cadence_qspi_apb: Make flash writes 32 bit aligned Make flash writes 32 bit aligned by using bounce buffers to deal with non 32 bit aligned buffers. This is required because as per TI K2G TRM[1], the external master is only permitted to issue 32-bit data interface writes until the last word of an indirect transfer. Otherwise indirect writes is known to fail sometimes. [1] http://www.ti.com/lit/ug/spruhy8g/spruhy8g.pdf Signed-off-by: Vignesh R Acked-by: Marek Vasut Acked-by: Simon Goldschmidt Reviewed-by: Jason Rush Acked-by: Jason Rush Reviewed-by: Jagan Teki --- drivers/spi/cadence_qspi_apb.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c index 70d0f43..aa3a9ff 100644 --- a/drivers/spi/cadence_qspi_apb.c +++ b/drivers/spi/cadence_qspi_apb.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "cadence_qspi.h" #define CQSPI_REG_POLL_US 1 /* 1us */ @@ -719,9 +720,23 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat, { unsigned int page_size = plat->page_size; unsigned int remaining = n_tx; + const u8 *bb_txbuf = txbuf; + void *bounce_buf = NULL; unsigned int write_bytes; int ret; + /* + * Use bounce buffer for non 32 bit aligned txbuf to avoid data + * aborts + */ + if ((uintptr_t)txbuf % 4) { + bounce_buf = malloc(n_tx); + if (!bounce_buf) + return -ENOMEM; + memcpy(bounce_buf, txbuf, n_tx); + bb_txbuf = bounce_buf; + } + /* Configure the indirect read transfer bytes */ writel(n_tx, plat->regbase + CQSPI_REG_INDIRECTWRBYTES); @@ -731,11 +746,11 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat, while (remaining > 0) { write_bytes = remaining > page_size ? page_size : remaining; - /* Handle non-4-byte aligned access to avoid data abort. */ - if (((uintptr_t)txbuf % 4) || (write_bytes % 4)) - writesb(plat->ahbbase, txbuf, write_bytes); - else - writesl(plat->ahbbase, txbuf, write_bytes >> 2); + writesl(plat->ahbbase, bb_txbuf, write_bytes >> 2); + if (write_bytes % 4) + writesb(plat->ahbbase, + bb_txbuf + rounddown(write_bytes, 4), + write_bytes % 4); ret = wait_for_bit_le32(plat->regbase + CQSPI_REG_SDRAMLEVEL, CQSPI_REG_SDRAMLEVEL_WR_MASK << @@ -745,7 +760,7 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat, goto failwr; } - txbuf += write_bytes; + bb_txbuf += write_bytes; remaining -= write_bytes; } @@ -760,12 +775,16 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat, /* Clear indirect completion status */ writel(CQSPI_REG_INDIRECTWR_DONE, plat->regbase + CQSPI_REG_INDIRECTWR); + if (bounce_buf) + free(bounce_buf); return 0; failwr: /* Cancel the indirect write */ writel(CQSPI_REG_INDIRECTWR_CANCEL, plat->regbase + CQSPI_REG_INDIRECTWR); + if (bounce_buf) + free(bounce_buf); return ret; }