diff options
| -rw-r--r-- | Documentation/memory-devices/ti-emif.txt | 57 | ||||
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/memory/Kconfig | 22 | ||||
| -rw-r--r-- | drivers/memory/Makefile | 5 | ||||
| -rw-r--r-- | drivers/memory/emif.c | 289 | ||||
| -rw-r--r-- | drivers/memory/emif.h | 7 | ||||
| -rw-r--r-- | include/linux/platform_data/emif_plat.h | 128 |
8 files changed, 511 insertions, 0 deletions
diff --git a/Documentation/memory-devices/ti-emif.txt b/Documentation/memory-devices/ti-emif.txt new file mode 100644 index 0000000..f4ad9a7 --- /dev/null +++ b/Documentation/memory-devices/ti-emif.txt @@ -0,0 +1,57 @@ +TI EMIF SDRAM Controller Driver: + +Author +======== +Aneesh V <aneesh@ti.com> + +Location +============ +driver/memory/emif.c + +Supported SoCs: +=================== +TI OMAP44xx +TI OMAP54xx + +Menuconfig option: +========================== +Device Drivers + Memory devices + Texas Instruments EMIF driver + +Description +=========== +This driver is for the EMIF module available in Texas Instruments +SoCs. EMIF is an SDRAM controller that, based on its revision, +supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols. +This driver takes care of only LPDDR2 memories presently. The +functions of the driver includes re-configuring AC timing +parameters and other settings during frequency, voltage and +temperature changes + +Platform Data (see include/linux/platform_data/emif_plat.h): +===================================================================== +DDR device details and other board dependent and SoC dependent +information can be passed through platform data (struct emif_platform_data) +- DDR device details: 'struct ddr_device_info' +- Device AC timings: 'struct lpddr2_timings' and 'struct lpddr2_min_tck' +- Custom configurations: customizable policy options through + 'struct emif_custom_configs' +- IP revision +- PHY type + +Interface to the external world: +================================ +EMIF driver registers notifiers for voltage and frequency changes +affecting EMIF and takes appropriate actions when these are invoked. +- freq_pre_notify_handling() +- freq_post_notify_handling() +- volt_notify_handling() + +Debugfs +======== +The driver creates two debugfs entries per device. +- regcache_dump : dump of register values calculated and saved for all + frequencies used so far. +- mr4 : last polled value of MR4 register in the LPDDR2 device. MR4 + indicates the current temperature level of the device. diff --git a/drivers/Kconfig b/drivers/Kconfig index 0233ad9..63b8182 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -142,4 +142,6 @@ source "drivers/devfreq/Kconfig" source "drivers/extcon/Kconfig" +source "drivers/memory/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index c41dfa9..265b506 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -135,3 +135,4 @@ obj-$(CONFIG_HYPERV) += hv/ obj-$(CONFIG_PM_DEVFREQ) += devfreq/ obj-$(CONFIG_EXTCON) += extcon/ +obj-$(CONFIG_MEMORY) += memory/ diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig new file mode 100644 index 0000000..b08327c --- /dev/null +++ b/drivers/memory/Kconfig @@ -0,0 +1,22 @@ +# +# Memory devices +# + +menuconfig MEMORY + bool "Memory Controller drivers" + +if MEMORY + +config TI_EMIF + tristate "Texas Instruments EMIF driver" + select DDR + help + This driver is for the EMIF module available in Texas Instruments + SoCs. EMIF is an SDRAM controller that, based on its revision, + supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols. + This driver takes care of only LPDDR2 memories presently. The + functions of the driver includes re-configuring AC timing + parameters and other settings during frequency, voltage and + temperature changes + +endif diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile new file mode 100644 index 0000000..e27f80b --- /dev/null +++ b/drivers/memory/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for memory devices +# + +obj-$(CONFIG_TI_EMIF) += emif.o diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c new file mode 100644 index 0000000..7486d7e --- /dev/null +++ b/drivers/memory/emif.c @@ -0,0 +1,289 @@ +/* + * EMIF driver + * + * Copyright (C) 2012 Texas Instruments, Inc. + * + * Aneesh V <aneesh@ti.com> + * Santosh Shilimkar <santosh.shilimkar@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. + */ +#include <linux/kernel.h> +#include <linux/reboot.h> +#include <linux/platform_data/emif_plat.h> +#include <linux/io.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/seq_file.h> +#include <linux/module.h> +#include <linux/list.h> +#include <memory/jedec_ddr.h> +#include "emif.h" + +/** + * struct emif_data - Per device static data for driver's use + * @duplicate: Whether the DDR devices attached to this EMIF + * instance are exactly same as that on EMIF1. In + * this case we can save some memory and processing + * @temperature_level: Maximum temperature of LPDDR2 devices attached + * to this EMIF - read from MR4 register. If there + * are two devices attached to this EMIF, this + * value is the maximum of the two temperature + * levels. + * @node: node in the device list + * @base: base address of memory-mapped IO registers. + * @dev: device pointer. + * @plat_data: Pointer to saved platform data. + */ +struct emif_data { + u8 duplicate; + u8 temperature_level; + struct list_head node; + void __iomem *base; + struct device *dev; + struct emif_platform_data *plat_data; +}; + +static struct emif_data *emif1; +static LIST_HEAD(device_list); + +static void get_default_timings(struct emif_data *emif) +{ + struct emif_platform_data *pd = emif->plat_data; + + pd->timings = lpddr2_jedec_timings; + pd->timings_arr_size = ARRAY_SIZE(lpddr2_jedec_timings); + + dev_warn(emif->dev, "%s: using default timings\n", __func__); +} + +static int is_dev_data_valid(u32 type, u32 density, u32 io_width, u32 phy_type, + u32 ip_rev, struct device *dev) +{ + int valid; + + valid = (type == DDR_TYPE_LPDDR2_S4 || + type == DDR_TYPE_LPDDR2_S2) + && (density >= DDR_DENSITY_64Mb + && density <= DDR_DENSITY_8Gb) + && (io_width >= DDR_IO_WIDTH_8 + && io_width <= DDR_IO_WIDTH_32); + + /* Combinations of EMIF and PHY revisions that we support today */ + switch (ip_rev) { + case EMIF_4D: + valid = valid && (phy_type == EMIF_PHY_TYPE_ATTILAPHY); + break; + case EMIF_4D5: + valid = valid && (phy_type == EMIF_PHY_TYPE_INTELLIPHY); + break; + default: + valid = 0; + } + + if (!valid) + dev_err(dev, "%s: invalid DDR details\n", __func__); + return valid; +} + +static int is_custom_config_valid(struct emif_custom_configs *cust_cfgs, + struct device *dev) +{ + int valid = 1; + + if ((cust_cfgs->mask & EMIF_CUSTOM_CONFIG_LPMODE) && + (cust_cfgs->lpmode != EMIF_LP_MODE_DISABLE)) + valid = cust_cfgs->lpmode_freq_threshold && + cust_cfgs->lpmode_timeout_performance && + cust_cfgs->lpmode_timeout_power; + + if (cust_cfgs->mask & EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL) + valid = valid && cust_cfgs->temp_alert_poll_interval_ms; + + if (!valid) + dev_warn(dev, "%s: invalid custom configs\n", __func__); + + return valid; +} + +static struct emif_data *__init_or_module get_device_details( + struct platform_device *pdev) +{ + u32 size; + struct emif_data *emif = NULL; + struct ddr_device_info *dev_info; + struct emif_custom_configs *cust_cfgs; + struct emif_platform_data *pd; + struct device *dev; + void *temp; + + pd = pdev->dev.platform_data; + dev = &pdev->dev; + + if (!(pd && pd->device_info && is_dev_data_valid(pd->device_info->type, + pd->device_info->density, pd->device_info->io_width, + pd->phy_type, pd->ip_rev, dev))) { + dev_err(dev, "%s: invalid device data\n", __func__); + goto error; + } + + emif = devm_kzalloc(dev, sizeof(*emif), GFP_KERNEL); + temp = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); + dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL); + + if (!emif || !pd || !dev_info) { + dev_err(dev, "%s:%d: allocation error\n", __func__, __LINE__); + goto error; + } + + memcpy(temp, pd, sizeof(*pd)); + pd = temp; + memcpy(dev_info, pd->device_info, sizeof(*dev_info)); + + pd->device_info = dev_info; + emif->plat_data = pd; + emif->dev = dev; + emif->temperature_level = SDRAM_TEMP_NOMINAL; + + /* + * For EMIF instances other than EMIF1 see if the devices connected + * are exactly same as on EMIF1(which is typically the case). If so, + * mark it as a duplicate of EMIF1 and skip copying timings data. + * This will save some memory and some computation later. + */ + emif->duplicate = emif1 && (memcmp(dev_info, + emif1->plat_data->device_info, + sizeof(struct ddr_device_info)) == 0); + + if (emif->duplicate) { + pd->timings = NULL; + pd->min_tck = NULL; + goto out; + } else if (emif1) { + dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n", + __func__); + } + + /* + * Copy custom configs - ignore allocation error, if any, as + * custom_configs is not very critical + */ + cust_cfgs = pd->custom_configs; + if (cust_cfgs && is_custom_config_valid(cust_cfgs, dev)) { + temp = devm_kzalloc(dev, sizeof(*cust_cfgs), GFP_KERNEL); + if (temp) + memcpy(temp, cust_cfgs, sizeof(*cust_cfgs)); + else + dev_warn(dev, "%s:%d: allocation error\n", __func__, + __LINE__); + pd->custom_configs = temp; + } + + /* + * Copy timings and min-tck values from platform data. If it is not + * available or if memory allocation fails, use JEDEC defaults + */ + size = sizeof(struct lpddr2_timings) * pd->timings_arr_size; + if (pd->timings) { + temp = devm_kzalloc(dev, size, GFP_KERNEL); + if (temp) { + memcpy(temp, pd->timings, sizeof(*pd->timings)); + pd->timings = temp; + } else { + dev_warn(dev, "%s:%d: allocation error\n", __func__, + __LINE__); + get_default_timings(emif); + } + } else { + get_default_timings(emif); + } + + if (pd->min_tck) { + temp = devm_kzalloc(dev, sizeof(*pd->min_tck), GFP_KERNEL); + if (temp) { + memcpy(temp, pd->min_tck, sizeof(*pd->min_tck)); + pd->min_tck = temp; + } else { + dev_warn(dev, "%s:%d: allocation error\n", __func__, + __LINE__); + pd->min_tck = &lpddr2_jedec_min_tck; + } + } else { + pd->min_tck = &lpddr2_jedec_min_tck; + } + +out: + return emif; + +error: + return NULL; +} + +static int __init_or_module emif_probe(struct platform_device *pdev) +{ + struct emif_data *emif; + struct resource *res; + + emif = get_device_details(pdev); + if (!emif) { + pr_err("%s: error getting device data\n", __func__); + goto error; + } + + if (!emif1) + emif1 = emif; + + list_add(&emif->node, &device_list); + + /* Save pointers to each other in emif and device structures */ + emif->dev = &pdev->dev; + platform_set_drvdata(pdev, emif); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(emif->dev, "%s: error getting memory resource\n", + __func__); + goto error; + } + + emif->base = devm_request_and_ioremap(emif->dev, res); + if (!emif->base) { + dev_err(emif->dev, "%s: devm_request_and_ioremap() failed\n", + __func__); + goto error; + } + + dev_info(&pdev->dev, "%s: device configured with addr = %p\n", + __func__, emif->base); + + return 0; +error: + return -ENODEV; +} + +static struct platform_driver emif_driver = { + .driver = { + .name = "emif", + }, +}; + +static int __init_or_module emif_register(void) +{ + return platform_driver_probe(&emif_driver, emif_probe); +} + +static void __exit emif_unregister(void) +{ + platform_driver_unregister(&emif_driver); +} + +module_init(emif_register); +module_exit(emif_unregister); +MODULE_DESCRIPTION("TI EMIF SDRAM Controller Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:emif"); +MODULE_AUTHOR("Texas Instruments Inc"); diff --git a/drivers/memory/emif.h b/drivers/memory/emif.h index 44b97df..692b2a8 100644 --- a/drivers/memory/emif.h +++ b/drivers/memory/emif.h @@ -12,6 +12,13 @@ #ifndef __EMIF_H #define __EMIF_H +/* + * Maximum number of different frequencies supported by EMIF driver + * Determines the number of entries in the pointer array for register + * cache + */ +#define EMIF_MAX_NUM_FREQUENCIES 6 + /* Registers offset */ #define EMIF_MODULE_ID_AND_REVISION 0x0000 #define EMIF_STATUS 0x0004 diff --git a/include/linux/platform_data/emif_plat.h b/include/linux/platform_data/emif_plat.h new file mode 100644 index 0000000..03378ca --- /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 */ |
