[PATCH 34/42] ddr: imx9: Add workaround for DDRPHY rank-to-rank errata
Peng Fan (OSS)
peng.fan at oss.nxp.com
Fri Apr 28 06:08:39 CEST 2023
From: Ye Li <ye.li at nxp.com>
According to DDRPHY errata, the Rank-to-Rank Spacing and tphy_rdcsgap
specification does not include the Critical Delay Difference (CDD) to
properly define the required rank-to-rank read command spacing after
executing PHY training firmware.
Following the errata workaround, at the end of data training, we get
all CDD values through the MessageBlock, then re-configure the DDRC
timing of WWT/WRT/RRT/RWT with comparing MAX CDD values.
Signed-off-by: Ye Li <ye.li at nxp.com>
Acked-by: Peng Fan <peng.fan at nxp.com>
---
arch/arm/include/asm/arch-imx9/ddr.h | 2 +
drivers/ddr/imx/imx9/ddr_init.c | 122 +++++++++++++++++++++++++++
2 files changed, 124 insertions(+)
diff --git a/arch/arm/include/asm/arch-imx9/ddr.h b/arch/arm/include/asm/arch-imx9/ddr.h
index 62e6f7dda53..8e4f946e5b0 100644
--- a/arch/arm/include/asm/arch-imx9/ddr.h
+++ b/arch/arm/include/asm/arch-imx9/ddr.h
@@ -14,7 +14,9 @@
#define DDRMIX_BLK_CTRL_BASE 0x4E010000
#define REG_DDRDSR_2 (DDR_CTL_BASE + 0xB24)
+#define REG_DDR_TIMING_CFG_0 (DDR_CTL_BASE + 0x104)
#define REG_DDR_SDRAM_CFG (DDR_CTL_BASE + 0x110)
+#define REG_DDR_TIMING_CFG_4 (DDR_CTL_BASE + 0x160)
#define REG_DDR_DEBUG_19 (DDR_CTL_BASE + 0xF48)
#define SRC_BASE_ADDR (0x44460000)
diff --git a/drivers/ddr/imx/imx9/ddr_init.c b/drivers/ddr/imx/imx9/ddr_init.c
index 8b8ec7f8de3..a1d953026f3 100644
--- a/drivers/ddr/imx/imx9/ddr_init.c
+++ b/drivers/ddr/imx/imx9/ddr_init.c
@@ -12,6 +12,13 @@
#include <asm/arch/sys_proto.h>
#include <linux/delay.h>
+static unsigned int g_cdd_rr_max[4];
+static unsigned int g_cdd_rw_max[4];
+static unsigned int g_cdd_wr_max[4];
+static unsigned int g_cdd_ww_max[4];
+
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
void ddrphy_coldreset(void)
{
/* dramphy_apb_n default 1 , assert -> 0, de_assert -> 1 */
@@ -74,8 +81,121 @@ void ddrc_config(struct dram_cfg_param *ddrc_config, int num)
}
}
+static unsigned int look_for_max(unsigned int data[], unsigned int addr_start,
+ unsigned int addr_end)
+{
+ unsigned int i, imax = 0;
+
+ for (i = addr_start; i <= addr_end; i++) {
+ if (((data[i] >> 7) == 0) && data[i] > imax)
+ imax = data[i];
+ }
+
+ return imax;
+}
+
void get_trained_CDD(u32 fsp)
{
+ unsigned int i, tmp;
+ unsigned int cdd_cha[12], cdd_chb[12];
+ unsigned int cdd_cha_rr_max, cdd_cha_rw_max, cdd_cha_wr_max, cdd_cha_ww_max;
+ unsigned int cdd_chb_rr_max, cdd_chb_rw_max, cdd_chb_wr_max, cdd_chb_ww_max;
+
+ for (i = 0; i < 6; i++) {
+ tmp = dwc_ddrphy_apb_rd(0x54013 + i);
+ cdd_cha[i * 2] = tmp & 0xff;
+ cdd_cha[i * 2 + 1] = (tmp >> 8) & 0xff;
+ }
+
+ for (i = 0; i < 7; i++) {
+ tmp = dwc_ddrphy_apb_rd(0x5402c + i);
+
+ if (i == 0) {
+ cdd_chb[0] = (tmp >> 8) & 0xff;
+ } else if (i == 6) {
+ cdd_chb[11] = tmp & 0xff;
+ } else {
+ cdd_chb[i * 2 - 1] = tmp & 0xff;
+ cdd_chb[i * 2] = (tmp >> 8) & 0xff;
+ }
+ }
+
+ cdd_cha_rr_max = look_for_max(cdd_cha, 0, 1);
+ cdd_cha_rw_max = look_for_max(cdd_cha, 2, 5);
+ cdd_cha_wr_max = look_for_max(cdd_cha, 6, 9);
+ cdd_cha_ww_max = look_for_max(cdd_cha, 10, 11);
+ cdd_chb_rr_max = look_for_max(cdd_chb, 0, 1);
+ cdd_chb_rw_max = look_for_max(cdd_chb, 2, 5);
+ cdd_chb_wr_max = look_for_max(cdd_chb, 6, 9);
+ cdd_chb_ww_max = look_for_max(cdd_chb, 10, 11);
+ g_cdd_rr_max[fsp] = cdd_cha_rr_max > cdd_chb_rr_max ? cdd_cha_rr_max : cdd_chb_rr_max;
+ g_cdd_rw_max[fsp] = cdd_cha_rw_max > cdd_chb_rw_max ? cdd_cha_rw_max : cdd_chb_rw_max;
+ g_cdd_wr_max[fsp] = cdd_cha_wr_max > cdd_chb_wr_max ? cdd_cha_wr_max : cdd_chb_wr_max;
+ g_cdd_ww_max[fsp] = cdd_cha_ww_max > cdd_chb_ww_max ? cdd_cha_ww_max : cdd_chb_ww_max;
+}
+
+void update_umctl2_rank_space_setting(unsigned int pstat_num)
+{
+ u32 tmp, tmp_t;
+
+ int wwt, rrt, wrt, rwt;
+ int ext_wwt, ext_rrt, ext_wrt, ext_rwt;
+ int max_wwt, max_rrt, max_wrt, max_rwt;
+
+ /* read wwt, rrt, wrt, rwt fields from timing_cfg_0 */
+ tmp = readl(REG_DDR_TIMING_CFG_0);
+ wwt = (tmp >> 24) & 0x3;
+ rrt = (tmp >> 26) & 0x3;
+ wrt = (tmp >> 28) & 0x3;
+ rwt = (tmp >> 30) & 0x3;
+
+ /* read rxt_wwt, ext_rrt, ext_wrt, ext_rwt fields from timing_cfg_4 */
+ tmp_t = readl(REG_DDR_TIMING_CFG_4);
+ ext_wwt = (tmp >> 8) & 0x1;
+ ext_rrt = (tmp >> 10) & 0x1;
+ ext_wrt = (tmp >> 12) & 0x1;
+ ext_rwt = (tmp >> 14) & 0x3;
+
+ wwt = (ext_wwt << 2) | wwt;
+ rrt = (ext_rrt << 2) | wwt;
+ wrt = (ext_wrt << 2) | wrt;
+ rwt = (ext_rwt << 2) | rwt;
+
+ /* calculate the maximum between controller and cdd values */
+ max_wwt = MAX(g_cdd_ww_max[0], wwt);
+ max_rrt = MAX(g_cdd_rr_max[0], rrt);
+ max_wrt = MAX(g_cdd_wr_max[0], wrt);
+ max_rwt = MAX(g_cdd_rw_max[0], rwt);
+
+ /* verify values to see if are bigger then 7 or 15 (3 bits or 4 bits) */
+ if (max_wwt > 7)
+ max_wwt = 7;
+ if (max_rrt > 7)
+ max_rrt = 7;
+ if (max_wrt > 7)
+ max_wrt = 7;
+ if (max_rwt > 15)
+ max_rwt = 15;
+
+ /* recalculate timings for controller registers */
+ wwt = max_wwt & 0x3;
+ rrt = max_rrt & 0x3;
+ wrt = max_wrt & 0x3;
+ rwt = max_rwt & 0x3;
+
+ ext_wwt = (max_wwt & 0x4) >> 2;
+ ext_rrt = (max_rrt & 0x4) >> 2;
+ ext_wrt = (max_wrt & 0x4) >> 2;
+ ext_rwt = (max_rwt & 0xC) >> 2;
+
+ /* update timing_cfg_0 and timing_cfg_4 */
+ tmp = (tmp & 0x00ffffff) | (rwt << 30) | (wrt << 28) |
+ (rrt << 26) | (wwt << 24);
+ writel(tmp, REG_DDR_TIMING_CFG_0);
+
+ tmp_t = (tmp_t & 0xFFFF2AFF) | (ext_rwt << 14) |
+ (ext_wrt << 12) | (ext_rrt << 10) | (ext_wwt << 8);
+ writel(tmp_t, REG_DDR_TIMING_CFG_4);
}
int ddr_init(struct dram_timing_info *dram_timing)
@@ -112,6 +232,8 @@ int ddr_init(struct dram_timing_info *dram_timing)
ddrc_config(dram_timing->ddrc_cfg, dram_timing->ddrc_cfg_num);
debug("DDRINFO: ddrc config done\n");
+ update_umctl2_rank_space_setting(dram_timing->fsp_msg_num - 1);
+
#ifdef CONFIG_IMX9_DRAM_PM_COUNTER
writel(0x200000, REG_DDR_DEBUG_19);
#endif
--
2.40.0
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