The imx8mn has a 16-bit SDRAM bus width access but the calculation of the memory size treat it as a 32-bit width bus which makes the memory calculation to be wrong (meminfo wrong and memtest fails).
There is a difference between the imx7 and the imx8 familys. The imx8 family has a device config field in the master register of the DDRC controller which the imx7 family doesn't have (the bus width is 32-bit as default). The device config field together with the DQ configuration tells us the actual bus width of the device for a correct mem size calculaton. >From the imx8mn reference manual: +----------------------------------------------------+ | Field | Function | |----------------------------------------------------| | 31-30 | Indicates the configuration of the | | | device used in the system. | | device_config | 00b - x4 device | | | 01b - x8 device | | | 10b - x16 device | | | 11b - x32 device | +----------------------------------------------------+ ... ... Tested on the IMX8MN Evk with 2GB DDR4 and on a IMX8MN custom board with 2GB LPDDR4, checked size and made memory test. Signed-off-by: Joacim Zetterling <[email protected]> --- arch/arm/mach-imx/esdctl.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-imx/esdctl.c b/arch/arm/mach-imx/esdctl.c index e56da3cb76d4..f80d94f2fca0 100644 --- a/arch/arm/mach-imx/esdctl.c +++ b/arch/arm/mach-imx/esdctl.c @@ -320,6 +320,7 @@ static int vf610_ddrmc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) #define DDRC_MSTR_LPDDR4 BIT(5) #define DDRC_MSTR_DATA_BUS_WIDTH GENMASK(13, 12) #define DDRC_MSTR_ACTIVE_RANKS GENMASK(27, 24) +#define DDRC_MSTR_DEVICE_CONFIG GENMASK(31, 30) #define DDRC_ADDRMAP0_CS_BIT1 GENMASK(12, 8) @@ -361,7 +362,7 @@ static resource_size_t imx_ddrc_sdram_size(void __iomem *ddrc, const u32 addrmap[], u8 col_max, const u8 col_b[], unsigned int col_b_num, u8 row_max, const u8 row_b[], unsigned int row_b_num, - bool reduced_adress_space) + bool reduced_adress_space, bool is_imx8) { const u32 mstr = readl(ddrc + DDRC_MSTR); unsigned int banks, ranks, columns, rows, active_ranks, width; @@ -384,15 +385,20 @@ imx_ddrc_sdram_size(void __iomem *ddrc, const u32 addrmap[], BUG(); } + if (is_imx8) + width = (1 << FIELD_GET(DDRC_MSTR_DEVICE_CONFIG, mstr)) >> 1; + else + width = 4; + switch (FIELD_GET(DDRC_MSTR_DATA_BUS_WIDTH, mstr)) { case 0b00: /* Full DQ bus */ width = 4; break; case 0b01: /* Half DQ bus */ - width = 2; + width >>= 1; break; case 0b10: /* Quarter DQ bus */ - width = 1; + width >>= 2; break; default: BUG(); @@ -466,7 +472,7 @@ static resource_size_t imx8m_ddrc_sdram_size(void __iomem *ddrc) return imx_ddrc_sdram_size(ddrc, addrmap, 12, ARRAY_AND_SIZE(col_b), 16, ARRAY_AND_SIZE(row_b), - reduced_adress_space); + reduced_adress_space, true); } static int imx8m_ddrc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) @@ -508,7 +514,7 @@ static resource_size_t imx7d_ddrc_sdram_size(void __iomem *ddrc) return imx_ddrc_sdram_size(ddrc, addrmap, 11, ARRAY_AND_SIZE(col_b), 15, ARRAY_AND_SIZE(row_b), - reduced_adress_space); + reduced_adress_space, false); } static int imx7d_ddrc_add_mem(void *mmdcbase, struct imx_esdctl_data *data) -- 2.25.1 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
