Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 TI EMIF SDRAM Controller Driver: 2 3 Author 4 ======== 5 Aneesh V <aneesh@ti.com> 6 7 Location 8 ============ 9 driver/memory/emif.c 10 11 Supported SoCs: 12 =================== 13 TI OMAP44xx 14 TI OMAP54xx 15 16 Menuconfig option: 17 ========================== 18 Device Drivers 19 Memory devices 20 Texas Instruments EMIF driver 21 22 Description 23 =========== 24 This driver is for the EMIF module available in Texas Instruments 25 SoCs. EMIF is an SDRAM controller that, based on its revision, 26 supports one or more of DDR2, DDR3, and LPDDR2 SDRAM protocols. 27 This driver takes care of only LPDDR2 memories presently. The 28 functions of the driver includes re-configuring AC timing 29 parameters and other settings during frequency, voltage and 30 temperature changes 31 32 Platform Data (see include/linux/platform_data/emif_plat.h): 33 ===================================================================== 34 DDR device details and other board dependent and SoC dependent 35 information can be passed through platform data (struct emif_platform_data) 36 - DDR device details: 'struct ddr_device_info' 37 - Device AC timings: 'struct lpddr2_timings' and 'struct lpddr2_min_tck' 38 - Custom configurations: customizable policy options through 39 'struct emif_custom_configs' 40 - IP revision 41 - PHY type 42 43 Interface to the external world: 44 ================================ 45 EMIF driver registers notifiers for voltage and frequency changes 46 affecting EMIF and takes appropriate actions when these are invoked. 47 - freq_pre_notify_handling() 48 - freq_post_notify_handling() 49 - volt_notify_handling() 50 51 Debugfs 52 ======== 53 The driver creates two debugfs entries per device. 54 - regcache_dump : dump of register values calculated and saved for all 55 frequencies used so far. 56 - mr4 : last polled value of MR4 register in the LPDDR2 device. MR4 57 indicates the current temperature level of the device.