[U-Boot] [PATCH] driver/ddr/fsl: Fix tXP and tCKE

[York Sun]

The driver was written using old DDR3 spec which only covers low speeds.
The value would be suboptimal for higher speeds. Fix both timing according
to latest DDR3 spec, remove tCKE as an config option.

Signed-off-by: York Sun <yorksun at freescale.com>
---
 drivers/ddr/fsl/ctrl_regs.c   |   28 ++++++++++++++++++++++------
 drivers/ddr/fsl/interactive.c |    2 --
 drivers/ddr/fsl/options.c     |    4 ----
 include/fsl_ddr_sdram.h       |    2 --
 4 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/drivers/ddr/fsl/ctrl_regs.c b/drivers/ddr/fsl/ctrl_regs.c
index 04e4178..c23c4be 100644
--- a/drivers/ddr/fsl/ctrl_regs.c
+++ b/drivers/ddr/fsl/ctrl_regs.c
@@ -297,10 +297,13 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
 	unsigned char taxpd_mclk = 0;
 	/* Mode register set cycle time (tMRD). */
 	unsigned char tmrd_mclk;
+#if defined(CONFIG_SYS_FSL_DDR4) || defined(CONFIG_SYS_FSL_DDR3)
+	const unsigned int mclk_ps = get_memory_clk_period_ps();
+#endif
 
 #ifdef CONFIG_SYS_FSL_DDR4
 	/* tXP=max(4nCK, 6ns) */
-	int txp = max((get_memory_clk_period_ps() * 4), 6000); /* unit=ps */
+	int txp = max(mclk_ps * 4, 6000); /* unit=ps */
 	trwt_mclk = 2;
 	twrt_mclk = 1;
 	act_pd_exit_mclk = picos_to_mclk(txp);
@@ -311,16 +314,19 @@ static void set_timing_cfg_0(fsl_ddr_cfg_regs_t *ddr,
 	 */
 	tmrd_mclk = max(24, picos_to_mclk(15000));
 #elif defined(CONFIG_SYS_FSL_DDR3)
+	unsigned int data_rate = get_ddr_freq(0);
+	int txp;
 	/*
 	 * (tXARD and tXARDS). Empirical?
 	 * The DDR3 spec has not tXARD,
 	 * we use the tXP instead of it.
-	 * tXP=max(3nCK, 7.5ns) for DDR3.
+	 * tXP=max(3nCK, 7.5ns) for DDR3-800, 1066
+	 *     max(3nCK, 6ns) for DDR3-1333, 1600, 1866, 2133
 	 * spec has not the tAXPD, we use
 	 * tAXPD=1, need design to confirm.
 	 */
-	int txp = max((get_memory_clk_period_ps() * 3), 7500); /* unit=ps */
-	unsigned int data_rate = get_ddr_freq(0);
+	txp = max(mclk_ps * 3, (mclk_ps > 1540 ? 7500 : 6000));
+
 	tmrd_mclk = 4;
 	/* set the turnaround time */
 
@@ -578,6 +584,9 @@ static void set_timing_cfg_2(fsl_ddr_cfg_regs_t *ddr,
 	unsigned char cke_pls;
 	/* Window for four activates (tFAW) */
 	unsigned short four_act;
+#ifdef CONFIG_SYS_FSL_DDR3
+	const unsigned int mclk_ps = get_memory_clk_period_ps();
+#endif
 
 	/* FIXME add check that this must be less than acttorw_mclk */
 	add_lat_mclk = additive_latency;
@@ -619,10 +628,17 @@ static void set_timing_cfg_2(fsl_ddr_cfg_regs_t *ddr,
 #ifdef CONFIG_SYS_FSL_DDR4
 	cpo = 0;
 	cke_pls = max(3, picos_to_mclk(5000));
+#elif defined(CONFIG_SYS_FSL_DDR3)
+	/*
+	 * cke pulse = max(3nCK, 7.5ns) for DDR3-800
+	 *             max(3nCK, 5.625ns) for DDR3-1066, 1333
+	 *             max(3nCK, 5ns) for DDR3-1600, 1866, 2133
+	 */
+	cke_pls = max(3, picos_to_mclk(mclk_ps > 1870 ? 7500 :
+				       (mclk_ps > 1245 ? 5625 : 5000)));
 #else
-	cke_pls = picos_to_mclk(popts->tcke_clock_pulse_width_ps);
+	cke_pls = FSL_DDR_MIN_TCKE_PULSE_WIDTH_DDR;
 #endif
-
 	four_act = picos_to_mclk(popts->tfaw_window_four_activates_ps);
 
 	ddr->timing_cfg_2 = (0
diff --git a/drivers/ddr/fsl/interactive.c b/drivers/ddr/fsl/interactive.c
index 7fb4187..91ed3ea 100644
--- a/drivers/ddr/fsl/interactive.c
+++ b/drivers/ddr/fsl/interactive.c
@@ -516,7 +516,6 @@ static void fsl_ddr_options_edit(fsl_ddr_info_t *pinfo,
 		CTRL_OPTIONS(rcw_2),
 		CTRL_OPTIONS(ddr_cdr1),
 		CTRL_OPTIONS(ddr_cdr2),
-		CTRL_OPTIONS(tcke_clock_pulse_width_ps),
 		CTRL_OPTIONS(tfaw_window_four_activates_ps),
 		CTRL_OPTIONS(trwt_override),
 		CTRL_OPTIONS(trwt),
@@ -806,7 +805,6 @@ static void print_memctl_options(const memctl_options_t *popts)
 		CTRL_OPTIONS(rcw_2),
 		CTRL_OPTIONS_HEX(ddr_cdr1),
 		CTRL_OPTIONS_HEX(ddr_cdr2),
-		CTRL_OPTIONS(tcke_clock_pulse_width_ps),
 		CTRL_OPTIONS(tfaw_window_four_activates_ps),
 		CTRL_OPTIONS(trwt_override),
 		CTRL_OPTIONS(trwt),
diff --git a/drivers/ddr/fsl/options.c b/drivers/ddr/fsl/options.c
index 5986e1a..42b9c15 100644
--- a/drivers/ddr/fsl/options.c
+++ b/drivers/ddr/fsl/options.c
@@ -777,10 +777,6 @@ unsigned int populate_memctl_options(int all_dimms_registered,
 	 */
 	popts->bstopre = 0x100;
 
-	/* Minimum CKE pulse width -- tCKE(MIN) */
-	popts->tcke_clock_pulse_width_ps
-		= mclk_to_picos(FSL_DDR_MIN_TCKE_PULSE_WIDTH_DDR);
-
 	/*
 	 * Window for four activates -- tFAW
 	 *
diff --git a/include/fsl_ddr_sdram.h b/include/fsl_ddr_sdram.h
index e8a2db9..6846c7d 100644
--- a/include/fsl_ddr_sdram.h
+++ b/include/fsl_ddr_sdram.h
@@ -51,7 +51,6 @@ typedef ddr2_spd_eeprom_t generic_spd_eeprom_t;
 #define CONFIG_FSL_SDRAM_TYPE	SDRAM_TYPE_DDR2
 #endif
 #elif defined(CONFIG_SYS_FSL_DDR3)
-#define FSL_DDR_MIN_TCKE_PULSE_WIDTH_DDR	(3)	/* FIXME */
 typedef ddr3_spd_eeprom_t generic_spd_eeprom_t;
 #ifndef CONFIG_FSL_SDRAM_TYPE
 #define CONFIG_FSL_SDRAM_TYPE	SDRAM_TYPE_DDR3
@@ -350,7 +349,6 @@ typedef struct memctl_options_s {
 	unsigned int twot_en;
 	unsigned int threet_en;
 	unsigned int bstopre;
-	unsigned int tcke_clock_pulse_width_ps;	/* tCKE */
 	unsigned int tfaw_window_four_activates_ps;	/* tFAW --  FOUR_ACT */
 
 	/* Rtt impedance */
-- 
1.7.9.5