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>
This commit is contained in:
Aneesh V
Greg Kroah-Hartman
parent
6c8b0906cf
commit
7ec944538d
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@ -0,0 +1,57 @@
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TI EMIF SDRAM Controller Driver:
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Author
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========
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Aneesh V <aneesh@ti.com>
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Location
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============
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driver/memory/emif.c
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Supported SoCs:
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===================
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TI OMAP44xx
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TI OMAP54xx
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Menuconfig option:
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==========================
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Device Drivers
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Memory devices
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Texas Instruments EMIF driver
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Description
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===========
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This driver is for the EMIF module available in Texas Instruments
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SoCs. EMIF is an SDRAM controller that, based on its revision,
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supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols.
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This driver takes care of only LPDDR2 memories presently. The
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functions of the driver includes re-configuring AC timing
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parameters and other settings during frequency, voltage and
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temperature changes
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Platform Data (see include/linux/platform_data/emif_plat.h):
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=====================================================================
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DDR device details and other board dependent and SoC dependent
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information can be passed through platform data (struct emif_platform_data)
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- DDR device details: 'struct ddr_device_info'
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- Device AC timings: 'struct lpddr2_timings' and 'struct lpddr2_min_tck'
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- Custom configurations: customizable policy options through
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'struct emif_custom_configs'
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- IP revision
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- PHY type
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Interface to the external world:
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================================
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EMIF driver registers notifiers for voltage and frequency changes
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affecting EMIF and takes appropriate actions when these are invoked.
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- freq_pre_notify_handling()
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- freq_post_notify_handling()
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- volt_notify_handling()
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Debugfs
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========
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The driver creates two debugfs entries per device.
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- regcache_dump : dump of register values calculated and saved for all
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frequencies used so far.
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- mr4 : last polled value of MR4 register in the LPDDR2 device. MR4
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indicates the current temperature level of the device.
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@ -142,4 +142,6 @@ source "drivers/devfreq/Kconfig"
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source "drivers/extcon/Kconfig"
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source "drivers/memory/Kconfig"
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endmenu
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@ -135,3 +135,4 @@ obj-$(CONFIG_HYPERV) += hv/
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obj-$(CONFIG_PM_DEVFREQ) += devfreq/
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obj-$(CONFIG_EXTCON) += extcon/
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obj-$(CONFIG_MEMORY) += memory/
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@ -0,0 +1,22 @@
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#
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# Memory devices
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#
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menuconfig MEMORY
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bool "Memory Controller drivers"
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if MEMORY
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config TI_EMIF
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tristate "Texas Instruments EMIF driver"
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select DDR
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help
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This driver is for the EMIF module available in Texas Instruments
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SoCs. EMIF is an SDRAM controller that, based on its revision,
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supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols.
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This driver takes care of only LPDDR2 memories presently. The
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functions of the driver includes re-configuring AC timing
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parameters and other settings during frequency, voltage and
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temperature changes
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endif
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@ -0,0 +1,5 @@
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#
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# Makefile for memory devices
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#
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obj-$(CONFIG_TI_EMIF) += emif.o
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@ -0,0 +1,289 @@
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/*
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* EMIF driver
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*
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* Copyright (C) 2012 Texas Instruments, Inc.
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*
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* Aneesh V <aneesh@ti.com>
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* Santosh Shilimkar <santosh.shilimkar@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/reboot.h>
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#include <linux/platform_data/emif_plat.h>
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#include <linux/io.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/seq_file.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <memory/jedec_ddr.h>
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#include "emif.h"
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/**
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* struct emif_data - Per device static data for driver's use
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* @duplicate: Whether the DDR devices attached to this EMIF
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* instance are exactly same as that on EMIF1. In
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* this case we can save some memory and processing
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* @temperature_level: Maximum temperature of LPDDR2 devices attached
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* to this EMIF - read from MR4 register. If there
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* are two devices attached to this EMIF, this
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* value is the maximum of the two temperature
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* levels.
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* @node: node in the device list
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* @base: base address of memory-mapped IO registers.
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* @dev: device pointer.
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* @plat_data: Pointer to saved platform data.
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*/
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struct emif_data {
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u8 duplicate;
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u8 temperature_level;
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struct list_head node;
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void __iomem *base;
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struct device *dev;
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struct emif_platform_data *plat_data;
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};
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static struct emif_data *emif1;
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static LIST_HEAD(device_list);
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static void get_default_timings(struct emif_data *emif)
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{
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struct emif_platform_data *pd = emif->plat_data;
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pd->timings = lpddr2_jedec_timings;
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pd->timings_arr_size = ARRAY_SIZE(lpddr2_jedec_timings);
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dev_warn(emif->dev, "%s: using default timings\n", __func__);
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}
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static int is_dev_data_valid(u32 type, u32 density, u32 io_width, u32 phy_type,
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u32 ip_rev, struct device *dev)
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{
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int valid;
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valid = (type == DDR_TYPE_LPDDR2_S4 ||
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type == DDR_TYPE_LPDDR2_S2)
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&& (density >= DDR_DENSITY_64Mb
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&& density <= DDR_DENSITY_8Gb)
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&& (io_width >= DDR_IO_WIDTH_8
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&& io_width <= DDR_IO_WIDTH_32);
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/* Combinations of EMIF and PHY revisions that we support today */
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switch (ip_rev) {
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case EMIF_4D:
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valid = valid && (phy_type == EMIF_PHY_TYPE_ATTILAPHY);
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break;
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case EMIF_4D5:
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valid = valid && (phy_type == EMIF_PHY_TYPE_INTELLIPHY);
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break;
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default:
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valid = 0;
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}
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if (!valid)
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dev_err(dev, "%s: invalid DDR details\n", __func__);
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return valid;
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}
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static int is_custom_config_valid(struct emif_custom_configs *cust_cfgs,
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struct device *dev)
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{
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int valid = 1;
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if ((cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE) &&
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(cust_cfgs->lpmode != EMIF_LP_MODE_DISABLE))
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valid = cust_cfgs->lpmode_freq_threshold &&
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cust_cfgs->lpmode_timeout_performance &&
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cust_cfgs->lpmode_timeout_power;
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if (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL)
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valid = valid && cust_cfgs->temp_alert_poll_interval_ms;
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if (!valid)
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dev_warn(dev, "%s: invalid custom configs\n", __func__);
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return valid;
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}
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static struct emif_data *__init_or_module get_device_details(
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struct platform_device *pdev)
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{
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u32 size;
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struct emif_data *emif = NULL;
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struct ddr_device_info *dev_info;
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struct emif_custom_configs *cust_cfgs;
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struct emif_platform_data *pd;
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struct device *dev;
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void *temp;
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pd = pdev->dev.platform_data;
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dev = &pdev->dev;
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if (!(pd && pd->device_info && is_dev_data_valid(pd->device_info->type,
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pd->device_info->density, pd->device_info->io_width,
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pd->phy_type, pd->ip_rev, dev))) {
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dev_err(dev, "%s: invalid device data\n", __func__);
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goto error;
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}
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emif = devm_kzalloc(dev, sizeof(*emif), GFP_KERNEL);
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temp = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
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dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
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if (!emif || !pd || !dev_info) {
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dev_err(dev, "%s:%d: allocation error\n", __func__, __LINE__);
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goto error;
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}
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memcpy(temp, pd, sizeof(*pd));
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pd = temp;
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memcpy(dev_info, pd->device_info, sizeof(*dev_info));
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pd->device_info = dev_info;
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emif->plat_data = pd;
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emif->dev = dev;
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emif->temperature_level = SDRAM_TEMP_NOMINAL;
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/*
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* For EMIF instances other than EMIF1 see if the devices connected
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* are exactly same as on EMIF1(which is typically the case). If so,
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* mark it as a duplicate of EMIF1 and skip copying timings data.
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* This will save some memory and some computation later.
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*/
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emif->duplicate = emif1 && (memcmp(dev_info,
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emif1->plat_data->device_info,
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sizeof(struct ddr_device_info)) == 0);
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if (emif->duplicate) {
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pd->timings = NULL;
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pd->min_tck = NULL;
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goto out;
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} else if (emif1) {
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dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
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__func__);
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}
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/*
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* Copy custom configs - ignore allocation error, if any, as
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* custom_configs is not very critical
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*/
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cust_cfgs = pd->custom_configs;
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if (cust_cfgs && is_custom_config_valid(cust_cfgs, dev)) {
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temp = devm_kzalloc(dev, sizeof(*cust_cfgs), GFP_KERNEL);
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if (temp)
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memcpy(temp, cust_cfgs, sizeof(*cust_cfgs));
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else
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dev_warn(dev, "%s:%d: allocation error\n", __func__,
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__LINE__);
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pd->custom_configs = temp;
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}
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/*
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* Copy timings and min-tck values from platform data. If it is not
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* available or if memory allocation fails, use JEDEC defaults
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*/
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size = sizeof(struct lpddr2_timings) * pd->timings_arr_size;
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if (pd->timings) {
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temp = devm_kzalloc(dev, size, GFP_KERNEL);
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if (temp) {
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memcpy(temp, pd->timings, sizeof(*pd->timings));
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pd->timings = temp;
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} else {
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dev_warn(dev, "%s:%d: allocation error\n", __func__,
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__LINE__);
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get_default_timings(emif);
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}
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} else {
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get_default_timings(emif);
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}
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if (pd->min_tck) {
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temp = devm_kzalloc(dev, sizeof(*pd->min_tck), GFP_KERNEL);
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if (temp) {
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memcpy(temp, pd->min_tck, sizeof(*pd->min_tck));
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pd->min_tck = temp;
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} else {
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dev_warn(dev, "%s:%d: allocation error\n", __func__,
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__LINE__);
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pd->min_tck = &lpddr2_jedec_min_tck;
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}
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} else {
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pd->min_tck = &lpddr2_jedec_min_tck;
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}
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out:
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return emif;
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error:
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return NULL;
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}
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static int __init_or_module emif_probe(struct platform_device *pdev)
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{
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struct emif_data *emif;
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struct resource *res;
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emif = get_device_details(pdev);
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if (!emif) {
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pr_err("%s: error getting device data\n", __func__);
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goto error;
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}
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if (!emif1)
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emif1 = emif;
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list_add(&emif->node, &device_list);
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/* Save pointers to each other in emif and device structures */
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emif->dev = &pdev->dev;
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platform_set_drvdata(pdev, emif);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(emif->dev, "%s: error getting memory resource\n",
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__func__);
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goto error;
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}
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emif->base = devm_request_and_ioremap(emif->dev, res);
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if (!emif->base) {
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dev_err(emif->dev, "%s: devm_request_and_ioremap() failed\n",
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__func__);
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goto error;
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}
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dev_info(&pdev->dev, "%s: device configured with addr = %p\n",
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__func__, emif->base);
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return 0;
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error:
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return -ENODEV;
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}
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static struct platform_driver emif_driver = {
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.driver = {
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.name = "emif",
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},
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};
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static int __init_or_module emif_register(void)
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{
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return platform_driver_probe(&emif_driver, emif_probe);
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}
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static void __exit emif_unregister(void)
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{
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platform_driver_unregister(&emif_driver);
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}
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module_init(emif_register);
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module_exit(emif_unregister);
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MODULE_DESCRIPTION("TI EMIF SDRAM Controller Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:emif");
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MODULE_AUTHOR("Texas Instruments Inc");
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@ -12,6 +12,13 @@
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#ifndef __EMIF_H
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#define __EMIF_H
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/*
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* Maximum number of different frequencies supported by EMIF driver
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* Determines the number of entries in the pointer array for register
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* cache
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*/
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#define EMIF_MAX_NUM_FREQUENCIES 6
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/* Registers offset */
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#define EMIF_MODULE_ID_AND_REVISION 0x0000
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#define EMIF_STATUS 0x0004
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@ -0,0 +1,128 @@
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/*
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* Definitions for TI EMIF device platform data
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*
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* Copyright (C) 2012 Texas Instruments, Inc.
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*
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* Aneesh V <aneesh@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
|
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* published by the Free Software Foundation.
|
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*/
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#ifndef __EMIF_PLAT_H
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#define __EMIF_PLAT_H
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/* Low power modes - EMIF_PWR_MGMT_CTRL */
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#define EMIF_LP_MODE_DISABLE 0
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#define EMIF_LP_MODE_CLOCK_STOP 1
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#define EMIF_LP_MODE_SELF_REFRESH 2
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#define EMIF_LP_MODE_PWR_DN 4
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/* Hardware capabilities */
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#define EMIF_HW_CAPS_LL_INTERFACE 0x00000001
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/*
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* EMIF IP Revisions
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* EMIF4D - Used in OMAP4
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* EMIF4D5 - Used in OMAP5
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*/
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#define EMIF_4D 1
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#define EMIF_4D5 2
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/*
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* PHY types
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* ATTILAPHY - Used in OMAP4
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* INTELLIPHY - Used in OMAP5
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*/
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#define EMIF_PHY_TYPE_ATTILAPHY 1
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#define EMIF_PHY_TYPE_INTELLIPHY 2
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/* Custom config requests */
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#define EMIF_CUSTOM_CONFIG_LPMODE 0x00000001
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#define EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL 0x00000002
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#ifndef __ASSEMBLY__
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/**
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* struct ddr_device_info - All information about the DDR device except AC
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* timing parameters
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* @type: Device type (LPDDR2-S4, LPDDR2-S2 etc)
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* @density: Device density
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* @io_width: Bus width
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* @cs1_used: Whether there is a DDR device attached to the second
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* chip-select(CS1) of this EMIF instance
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* @cal_resistors_per_cs: Whether there is one calibration resistor per
|
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* chip-select or whether it's a single one for both
|
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* @manufacturer: Manufacturer name string
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*/
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struct ddr_device_info {
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u32 type;
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u32 density;
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u32 io_width;
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u32 cs1_used;
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u32 cal_resistors_per_cs;
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||||
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 */
|
||||
Reference in New Issue