memory: emif: add basic infrastructure for EMIF driver

EMIF is an SDRAM controller used in various Texas Instruments
SoCs. EMIF supports, based on its revision, one or more of
LPDDR2/DDR2/DDR3 protocols.

Add the basic infrastructure for EMIF driver that includes
driver registration, probe, parsing of platform data etc.

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>

1 files changed, 128 insertions, 0 deletions

diff --git a/include/linux/platform_data/emif_plat.h b/include/linux/platform_data/emif_plat.h
new file mode 100644
index 000000000000..03378ca84061
--- /dev/null
+++ b/include/linux/platform_data/emif_plat.h
@@ -0,0 +1,128 @@
+/*
+ * Definitions for TI EMIF device platform data
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * Aneesh V <aneesh@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __EMIF_PLAT_H
+#define __EMIF_PLAT_H
+
+/* Low power modes - EMIF_PWR_MGMT_CTRL */
+#define EMIF_LP_MODE_DISABLE				0
+#define EMIF_LP_MODE_CLOCK_STOP				1
+#define EMIF_LP_MODE_SELF_REFRESH			2
+#define EMIF_LP_MODE_PWR_DN				4
+
+/* Hardware capabilities */
+#define	EMIF_HW_CAPS_LL_INTERFACE			0x00000001
+
+/*
+ * EMIF IP Revisions
+ *	EMIF4D  - Used in OMAP4
+ *	EMIF4D5 - Used in OMAP5
+ */
+#define	EMIF_4D						1
+#define	EMIF_4D5					2
+
+/*
+ * PHY types
+ *	ATTILAPHY  - Used in OMAP4
+ *	INTELLIPHY - Used in OMAP5
+ */
+#define	EMIF_PHY_TYPE_ATTILAPHY				1
+#define	EMIF_PHY_TYPE_INTELLIPHY			2
+
+/* Custom config requests */
+#define EMIF_CUSTOM_CONFIG_LPMODE			0x00000001
+#define EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL	0x00000002
+
+#ifndef __ASSEMBLY__
+/**
+ * struct ddr_device_info - All information about the DDR device except AC
+ *		timing parameters
+ * @type:	Device type (LPDDR2-S4, LPDDR2-S2 etc)
+ * @density:	Device density
+ * @io_width:	Bus width
+ * @cs1_used:	Whether there is a DDR device attached to the second
+ *		chip-select(CS1) of this EMIF instance
+ * @cal_resistors_per_cs: Whether there is one calibration resistor per
+ *		chip-select or whether it's a single one for both
+ * @manufacturer: Manufacturer name string
+ */
+struct ddr_device_info {
+	u32	type;
+	u32	density;
+	u32	io_width;
+	u32	cs1_used;
+	u32	cal_resistors_per_cs;
+	char	manufacturer[10];
+};
+
+/**
+ * struct emif_custom_configs - Custom configuration parameters/policies
+ *		passed from the platform layer
+ * @mask:	Mask to indicate which configs are requested
+ * @lpmode:	LPMODE to be used in PWR_MGMT_CTRL register
+ * @lpmode_timeout_performance: Timeout before LPMODE entry when higher
+ *		performance is desired at the cost of power (typically
+ *		at higher OPPs)
+ * @lpmode_timeout_power: Timeout before LPMODE entry when better power
+ *		savings is desired and performance is not important
+ *		(typically at lower loads indicated by lower OPPs)
+ * @lpmode_freq_threshold: The DDR frequency threshold to identify between
+ *		the above two cases:
+ *		timeout = (freq >= lpmode_freq_threshold) ?
+ *			lpmode_timeout_performance :
+ *			lpmode_timeout_power;
+ * @temp_alert_poll_interval_ms: LPDDR2 MR4 polling interval at nominal
+ *		temperature(in milliseconds). When temperature is high
+ *		polling is done 4 times as frequently.
+ */
+struct emif_custom_configs {
+	u32 mask;
+	u32 lpmode;
+	u32 lpmode_timeout_performance;
+	u32 lpmode_timeout_power;
+	u32 lpmode_freq_threshold;
+	u32 temp_alert_poll_interval_ms;
+};
+
+/**
+ * struct emif_platform_data - Platform data passed on EMIF platform
+ *				device creation. Used by the driver.
+ * @hw_caps:		Hw capabilities of the EMIF IP in the respective SoC
+ * @device_info:	Device info structure containing information such
+ *			as type, bus width, density etc
+ * @timings:		Timings information from device datasheet passed
+ *			as an array of 'struct lpddr2_timings'. Can be NULL
+ *			if if default timings are ok
+ * @timings_arr_size:	Size of the timings array. Depends on the number
+ *			of different frequencies for which timings data
+ *			is provided
+ * @min_tck:		Minimum value of some timing parameters in terms
+ *			of number of cycles. Can be NULL if default values
+ *			are ok
+ * @custom_configs:	Custom configurations requested by SoC or board
+ *			code and the data for them. Can be NULL if default
+ *			configurations done by the driver are ok. See
+ *			documentation for 'struct emif_custom_configs' for
+ *			more details
+ */
+struct emif_platform_data {
+	u32 hw_caps;
+	struct ddr_device_info *device_info;
+	const struct lpddr2_timings *timings;
+	u32 timings_arr_size;
+	const struct lpddr2_min_tck *min_tck;
+	struct emif_custom_configs *custom_configs;
+	u32 ip_rev;
+	u32 phy_type;
+};
+#endif /* __ASSEMBLY__ */
+
+#endif /* __LINUX_EMIF_H */