powerpc/mpc8xxx: Add DDR2 to unified DDR driver

DDR2 has different ODT table and values. Adding table according to Samsung
application note.

Fix additive latency calculation to avoid interger underflow.

Also converted typedef dynamic_odt_t to struct dynamic_odt.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/cpu/mpc8xxx/ddr/lc_common_dimm_params.c

@@ -448,7 +448,8 @@ compute_lowest_common_dimm_parameters(const dimm_params_t *dimm_params,
 
 #if defined(CONFIG_FSL_DDR2)
 	if (lowest_good_caslat < 4) {
-		additive_latency = picos_to_mclk(tRCD_ps) - lowest_good_caslat;
+		additive_latency = (picos_to_mclk(tRCD_ps) > lowest_good_caslat)
+			? picos_to_mclk(tRCD_ps) - lowest_good_caslat : 0;
 		if (mclk_to_picos(additive_latency) > tRCD_ps) {
 			additive_latency = picos_to_mclk(tRCD_ps);
 			debug("setting additive_latency to %u because it was "

arch/powerpc/cpu/mpc8xxx/ddr/options.c

@@ -26,14 +26,15 @@ extern void fsl_ddr_board_options(memctl_options_t *popts,
 		dimm_params_t *pdimm,
 		unsigned int ctrl_num);
 
-typedef struct {
+struct dynamic_odt {
 	unsigned int odt_rd_cfg;
 	unsigned int odt_wr_cfg;
 	unsigned int odt_rtt_norm;
 	unsigned int odt_rtt_wr;
-} dynamic_odt_t;
+};
 
-static const dynamic_odt_t single_Q[4] = {
+#ifdef CONFIG_FSL_DDR3
+static const struct dynamic_odt single_Q[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_CS_AND_OTHER_DIMM,
@@ -60,7 +61,7 @@ static const dynamic_odt_t single_Q[4] = {
 	}
 };
 
-static const dynamic_odt_t single_D[4] = {
+static const struct dynamic_odt single_D[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_ALL,
@@ -77,7 +78,7 @@ static const dynamic_odt_t single_D[4] = {
 	{0, 0, 0, 0}
 };
 
-static const dynamic_odt_t single_S[4] = {
+static const struct dynamic_odt single_S[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_ALL,
@@ -89,7 +90,7 @@ static const dynamic_odt_t single_S[4] = {
 	{0, 0, 0, 0},
 };
 
-static const dynamic_odt_t dual_DD[4] = {
+static const struct dynamic_odt dual_DD[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_SAME_DIMM,
@@ -116,7 +117,7 @@ static const dynamic_odt_t dual_DD[4] = {
 	}
 };
 
-static const dynamic_odt_t dual_DS[4] = {
+static const struct dynamic_odt dual_DS[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_SAME_DIMM,
@@ -137,7 +138,7 @@ static const dynamic_odt_t dual_DS[4] = {
 	},
 	{0, 0, 0, 0}
 };
-static const dynamic_odt_t dual_SD[4] = {
+static const struct dynamic_odt dual_SD[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_OTHER_DIMM,
 		FSL_DDR_ODT_ALL,
@@ -159,7 +160,7 @@ static const dynamic_odt_t dual_SD[4] = {
 	}
 };
 
-static const dynamic_odt_t dual_SS[4] = {
+static const struct dynamic_odt dual_SS[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_OTHER_DIMM,
 		FSL_DDR_ODT_ALL,
@@ -176,7 +177,7 @@ static const dynamic_odt_t dual_SS[4] = {
 	{0, 0, 0, 0}
 };
 
-static const dynamic_odt_t dual_D0[4] = {
+static const struct dynamic_odt dual_D0[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_SAME_DIMM,
@@ -193,7 +194,7 @@ static const dynamic_odt_t dual_D0[4] = {
 	{0, 0, 0, 0}
 };
 
-static const dynamic_odt_t dual_0D[4] = {
+static const struct dynamic_odt dual_0D[4] = {
 	{0, 0, 0, 0},
 	{0, 0, 0, 0},
 	{	/* cs2 */
@@ -210,7 +211,7 @@ static const dynamic_odt_t dual_0D[4] = {
 	}
 };
 
-static const dynamic_odt_t dual_S0[4] = {
+static const struct dynamic_odt dual_S0[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_CS,
@@ -223,7 +224,7 @@ static const dynamic_odt_t dual_S0[4] = {
 
 };
 
-static const dynamic_odt_t dual_0S[4] = {
+static const struct dynamic_odt dual_0S[4] = {
 	{0, 0, 0, 0},
 	{0, 0, 0, 0},
 	{	/* cs2 */
@@ -236,7 +237,7 @@ static const dynamic_odt_t dual_0S[4] = {
 
 };
 
-static const dynamic_odt_t odt_unknown[4] = {
+static const struct dynamic_odt odt_unknown[4] = {
 	{	/* cs0 */
 		FSL_DDR_ODT_NEVER,
 		FSL_DDR_ODT_CS,
@@ -262,7 +263,218 @@ static const dynamic_odt_t odt_unknown[4] = {
 		DDR3_RTT_OFF
 	}
 };
+#else	/* CONFIG_FSL_DDR3 */
+static const struct dynamic_odt single_Q[4] = {
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0}
+};
+
+static const struct dynamic_odt single_D[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_ALL,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs1 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0}
+};
+
+static const struct dynamic_odt single_S[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_ALL,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+};
+
+static const struct dynamic_odt dual_DD[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs1 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	},
+	{	/* cs2 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs3 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	}
+};
+
+static const struct dynamic_odt dual_DS[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs1 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	},
+	{	/* cs2 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0}
+};
+
+static const struct dynamic_odt dual_SD[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{	/* cs2 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs3 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	}
+};
 
+static const struct dynamic_odt dual_SS[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{	/* cs2 */
+		FSL_DDR_ODT_OTHER_DIMM,
+		FSL_DDR_ODT_OTHER_DIMM,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0}
+};
+
+static const struct dynamic_odt dual_D0[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_ALL,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs1 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0}
+};
+
+static const struct dynamic_odt dual_0D[4] = {
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{	/* cs2 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_ALL,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs3 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	}
+};
+
+static const struct dynamic_odt dual_S0[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_CS,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{0, 0, 0, 0}
+
+};
+
+static const struct dynamic_odt dual_0S[4] = {
+	{0, 0, 0, 0},
+	{0, 0, 0, 0},
+	{	/* cs2 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_CS,
+		DDR2_RTT_150_OHM,
+		DDR2_RTT_OFF
+	},
+	{0, 0, 0, 0}
+
+};
+
+static const struct dynamic_odt odt_unknown[4] = {
+	{	/* cs0 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_CS,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs1 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	},
+	{	/* cs2 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_CS,
+		DDR2_RTT_75_OHM,
+		DDR2_RTT_OFF
+	},
+	{	/* cs3 */
+		FSL_DDR_ODT_NEVER,
+		FSL_DDR_ODT_NEVER,
+		DDR2_RTT_OFF,
+		DDR2_RTT_OFF
+	}
+};
+#endif
 unsigned int populate_memctl_options(int all_DIMMs_registered,
 			memctl_options_t *popts,
 			dimm_params_t *pdimm,
@@ -271,7 +483,7 @@ unsigned int populate_memctl_options(int all_DIMMs_registered,
 	unsigned int i;
 	char buffer[HWCONFIG_BUFFER_SIZE];
 	char *buf = NULL;
-	const dynamic_odt_t *pdodt = odt_unknown;
+	const struct dynamic_odt *pdodt = odt_unknown;
 	ulong ddr_freq;
 
 	/*
@@ -337,7 +549,7 @@ unsigned int populate_memctl_options(int all_DIMMs_registered,
 
 	/* Pick chip-select local options. */
 	for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
-#if defined(CONFIG_FSL_DDR3)
+#if defined(CONFIG_FSL_DDR3) || defined(CONFIG_FSL_DDR2)
 		popts->cs_local_opts[i].odt_rd_cfg = pdodt[i].odt_rd_cfg;
 		popts->cs_local_opts[i].odt_wr_cfg = pdodt[i].odt_wr_cfg;
 		popts->cs_local_opts[i].odt_rtt_norm = pdodt[i].odt_rtt_norm;

arch/powerpc/include/asm/fsl_ddr_sdram.h

@@ -31,6 +31,11 @@
 #define DDR3_RTT_20_OHM		4 /* RTT_Nom = RZQ/12 */
 #define DDR3_RTT_30_OHM		5 /* RTT_Nom = RZQ/8 */
 
+#define DDR2_RTT_OFF		0
+#define DDR2_RTT_75_OHM		1
+#define DDR2_RTT_150_OHM	2
+#define DDR2_RTT_50_OHM		3
+
 #if defined(CONFIG_FSL_DDR1)
 #define FSL_DDR_MIN_TCKE_PULSE_WIDTH_DDR	(1)
 typedef ddr1_spd_eeprom_t generic_spd_eeprom_t;

doc/README.fsl-ddr

@@ -170,3 +170,55 @@ Single slot system
 
 Reference http://www.xrosstalkmag.com/mag_issues/xrosstalk_oct08_final.pdf
 	  http://download.micron.com/pdf/technotes/ddr3/tn4108_ddr3_design_guide.pdf
+
+
+Table for ODT for DDR2
+======================
+Two slots system
++-----------------------+----------+---------------+-----------------------------+-----------------------------+
+|     Configuration     |          |DRAM controller|           Slot 1            |            Slot 2           |
++-----------+-----------+----------+-------+-------+--------------+--------------+--------------+--------------+
+|           |           |          |       |       |     Rank 1   |     Rank 2   |   Rank 1     |    Rank 2    |
++  Slot 1   |   Slot 2  |Write/Read| Write | Read  |-------+------+-------+------+-------+------+-------+------+
+|           |           |          |       |       | Write | Read | Write | Read | Write | Read | Write | Read |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 1  |  off  | 150   | off   | off  | off   | off  | 75    | 75   | off   | off  |
+| Dual Rank | Dual Rank |----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 2  |  off  | 150   | 75    | 75   | off   | off  | off   | off  | off   | off  |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 1  |  off  | 150   | off   | off  | off   | off  | 75    | 75   |       |      |
+| Dual Rank |Single Rank|----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 2  |  off  | 150   | 75    | 75   | off   | off  | off   | off  |       |      |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 1  |  off  | 150   | off   | off  |       |      | 75    | 75   | off   | off  |
+|Single Rank| Dual Rank |----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 2  |  off  | 150   | 75    | 75   |       |      | off   | off  | off   | off  |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 1  |  off  | 150   | off   | off  |       |      | 75    | 75   |       |      |
+|Single Rank|Single Rank|----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|           |           |  Slot 2  |  off  | 150   | 75    | 75   |       |      | off   | off  |       |      |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+| Dual Rank |   Empty   |  Slot 1  |  off  | 75    | 150   | off  | off   | off  |       |      |       |      |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|   Empty   | Dual Rank |  Slot 2  |  off  | 75    |       |      |       |      | 150   | off  | off   | off  |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|Single Rank|   Empty   |  Slot 1  |  off  | 75    | 150   | off  |       |      |       |      |       |      |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+|   Empty   |Single Rank|  Slot 2  |  off  | 75    |       |      |       |      | 150   | off  |       |      |
++-----------+-----------+----------+-------+-------+-------+------+-------+------+-------+------+-------+------+
+
+Single slot system
++-------------+------------+---------------+-----------------------------+
+|             |            |DRAM controller|     Rank 1   |    Rank 2    |
+|Configuration| Write/Read |-------+-------+-------+------+-------+------+
+|             |            | Write | Read  | Write | Read | Write | Read |
++-------------+------------+-------+-------+-------+------+-------+------+
+|             |   R1       | off   | 75    | 150   | off  | off   | off  |
+|  Dual Rank  |------------+-------+-------+-------+------+-------+------+
+|             |   R2       | off   | 75    | 150   | off  | off   | off  |
++-------------+------------+-------+-------+-------+------+-------+------+
+| Single Rank |   R1       | off   | 75    | 150   | off  |
++-------------+------------+-------+-------+-------+------+
+
+Reference http://www.samsung.com/global/business/semiconductor/products/dram/downloads/applicationnote/ddr2_odt_control_200603.pdf
+