memory: emif: handle frequency and voltage change events

Change SDRAM timings and other settings as necessary
on voltage and frequency changes. We calculate these
register settings based on data from the device data
sheet and inputs such a frequency, voltage state(stable
or ramping), temperature level etc.

TODO: frequency and voltage change handling needs to
be integrated with clock framework and regulator
framework respectively. This is not done today
due to missing pieces in the kernel.
Signed-off-by: Aneesh V <aneesh@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Benoit Cousson <b-cousson@ti.com>
[santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc]
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/memory/emif.h

@@ -19,6 +19,103 @@
  */
 #define EMIF_MAX_NUM_FREQUENCIES			6
 
+/* State of the core voltage */
+#define DDR_VOLTAGE_STABLE				0
+#define DDR_VOLTAGE_RAMPING				1
+
+/* Defines for timing De-rating */
+#define EMIF_NORMAL_TIMINGS				0
+#define EMIF_DERATED_TIMINGS				1
+
+/* Length of the forced read idle period in terms of cycles */
+#define EMIF_READ_IDLE_LEN_VAL				5
+
+/*
+ * forced read idle interval to be used when voltage
+ * is changed as part of DVFS/DPS - 1ms
+ */
+#define READ_IDLE_INTERVAL_DVFS				(1*1000000)
+
+/*
+ * Forced read idle interval to be used when voltage is stable
+ * 50us - or maximum value will do
+ */
+#define READ_IDLE_INTERVAL_NORMAL			(50*1000000)
+
+/* DLL calibration interval when voltage is NOT stable - 1us */
+#define DLL_CALIB_INTERVAL_DVFS				(1*1000000)
+
+#define DLL_CALIB_ACK_WAIT_VAL				5
+
+/* Interval between ZQCS commands - hw team recommended value */
+#define EMIF_ZQCS_INTERVAL_US				(50*1000)
+/* Enable ZQ Calibration on exiting Self-refresh */
+#define ZQ_SFEXITEN_ENABLE				1
+/*
+ * ZQ Calibration simultaneously on both chip-selects:
+ * Needs one calibration resistor per CS
+ */
+#define	ZQ_DUALCALEN_DISABLE				0
+#define	ZQ_DUALCALEN_ENABLE				1
+
+#define T_ZQCS_DEFAULT_NS				90
+#define T_ZQCL_DEFAULT_NS				360
+#define T_ZQINIT_DEFAULT_NS				1000
+
+/* DPD_EN */
+#define DPD_DISABLE					0
+#define DPD_ENABLE					1
+
+/*
+ * Default values for the low-power entry to be used if not provided by user.
+ * OMAP4/5 has a hw bug(i735) due to which this value can not be less than 512
+ * Timeout values are in DDR clock 'cycles' and frequency threshold in Hz
+ */
+#define EMIF_LP_MODE_TIMEOUT_PERFORMANCE		2048
+#define EMIF_LP_MODE_TIMEOUT_POWER			512
+#define EMIF_LP_MODE_FREQ_THRESHOLD			400000000
+
+/* DDR_PHY_CTRL_1 values for EMIF4D - ATTILA PHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_ATTILAPHY		0x049FF000
+#define EMIF_DLL_SLAVE_DLY_CTRL_400_MHZ_ATTILAPHY	0x41
+#define EMIF_DLL_SLAVE_DLY_CTRL_200_MHZ_ATTILAPHY	0x80
+#define EMIF_DLL_SLAVE_DLY_CTRL_100_MHZ_AND_LESS_ATTILAPHY 0xFF
+
+/* DDR_PHY_CTRL_1 values for EMIF4D5 INTELLIPHY combination */
+#define EMIF_DDR_PHY_CTRL_1_BASE_VAL_INTELLIPHY		0x0E084200
+#define EMIF_PHY_TOTAL_READ_LATENCY_INTELLIPHY_PS	10000
+
+/* TEMP_ALERT_CONFIG - corresponding to temp gradient 5 C/s */
+#define TEMP_ALERT_POLL_INTERVAL_DEFAULT_MS		360
+
+#define EMIF_T_CSTA					3
+#define EMIF_T_PDLL_UL					128
+
+/* External PHY control registers magic values */
+#define EMIF_EXT_PHY_CTRL_1_VAL				0x04020080
+#define EMIF_EXT_PHY_CTRL_5_VAL				0x04010040
+#define EMIF_EXT_PHY_CTRL_6_VAL				0x01004010
+#define EMIF_EXT_PHY_CTRL_7_VAL				0x00001004
+#define EMIF_EXT_PHY_CTRL_8_VAL				0x04010040
+#define EMIF_EXT_PHY_CTRL_9_VAL				0x01004010
+#define EMIF_EXT_PHY_CTRL_10_VAL			0x00001004
+#define EMIF_EXT_PHY_CTRL_11_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_12_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_13_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_14_VAL			0x80080080
+#define EMIF_EXT_PHY_CTRL_15_VAL			0x00800800
+#define EMIF_EXT_PHY_CTRL_16_VAL			0x08102040
+#define EMIF_EXT_PHY_CTRL_17_VAL			0x00000001
+#define EMIF_EXT_PHY_CTRL_18_VAL			0x540A8150
+#define EMIF_EXT_PHY_CTRL_19_VAL			0xA81502A0
+#define EMIF_EXT_PHY_CTRL_20_VAL			0x002A0540
+#define EMIF_EXT_PHY_CTRL_21_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_22_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_23_VAL			0x00000000
+#define EMIF_EXT_PHY_CTRL_24_VAL			0x00000077
+
+#define EMIF_INTELLI_PHY_DQS_GATE_OPENING_DELAY_PS	1200
+
 /* Registers offset */
 #define EMIF_MODULE_ID_AND_REVISION			0x0000
 #define EMIF_STATUS					0x0004
@@ -458,4 +555,35 @@
 #define READ_LATENCY_SHDW_SHIFT				0
 #define READ_LATENCY_SHDW_MASK				(0x1f << 0)
 
-#endif
+#ifndef __ASSEMBLY__
+/*
+ * Structure containing shadow of important registers in EMIF
+ * The calculation function fills in this structure to be later used for
+ * initialisation and DVFS
+ */
+struct emif_regs {
+	u32 freq;
+	u32 ref_ctrl_shdw;
+	u32 ref_ctrl_shdw_derated;
+	u32 sdram_tim1_shdw;
+	u32 sdram_tim1_shdw_derated;
+	u32 sdram_tim2_shdw;
+	u32 sdram_tim3_shdw;
+	u32 sdram_tim3_shdw_derated;
+	u32 pwr_mgmt_ctrl_shdw;
+	union {
+		u32 read_idle_ctrl_shdw_normal;
+		u32 dll_calib_ctrl_shdw_normal;
+	};
+	union {
+		u32 read_idle_ctrl_shdw_volt_ramp;
+		u32 dll_calib_ctrl_shdw_volt_ramp;
+	};
+
+	u32 phy_ctrl_1_shdw;
+	u32 ext_phy_ctrl_2_shdw;
+	u32 ext_phy_ctrl_3_shdw;
+	u32 ext_phy_ctrl_4_shdw;
+};
+#endif /* __ASSEMBLY__ */
+#endif /* __EMIF_H */