154 lines
4.8 KiB
C
154 lines
4.8 KiB
C
/*
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* OpenFirmware helpers for memory drivers
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*
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* Copyright (C) 2012 Texas Instruments, Inc.
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/list.h>
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#include <linux/of.h>
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#include <linux/gfp.h>
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#include <memory/jedec_ddr.h>
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#include <linux/export.h>
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/**
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* of_get_min_tck() - extract min timing values for ddr
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* @np: pointer to ddr device tree node
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* @device: device requesting for min timing values
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*
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* Populates the lpddr2_min_tck structure by extracting data
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* from device tree node. Returns a pointer to the populated
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* structure. If any error in populating the structure, returns
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* default min timings provided by JEDEC.
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*/
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const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
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struct device *dev)
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{
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int ret = 0;
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struct lpddr2_min_tck *min;
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min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
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if (!min)
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goto default_min_tck;
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ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
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ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
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ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
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ret |= of_property_read_u32(np, "tRASmin-min-tck", &min->tRASmin);
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ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
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ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
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ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
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ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
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ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE);
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ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR);
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ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
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if (ret) {
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devm_kfree(dev, min);
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goto default_min_tck;
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}
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return min;
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default_min_tck:
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dev_warn(dev, "%s: using default min-tck values\n", __func__);
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return &lpddr2_jedec_min_tck;
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}
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EXPORT_SYMBOL(of_get_min_tck);
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static int of_do_get_timings(struct device_node *np,
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struct lpddr2_timings *tim)
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{
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int ret;
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ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
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ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
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ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
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ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
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ret |= of_property_read_u32(np, "tWR", &tim->tWR);
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ret |= of_property_read_u32(np, "tRAS-min", &tim->tRAS_min);
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ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
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ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
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ret |= of_property_read_u32(np, "tXP", &tim->tXP);
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ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
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ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
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ret |= of_property_read_u32(np, "tDQSCK-max", &tim->tDQSCK_max);
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ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
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ret |= of_property_read_u32(np, "tZQCS", &tim->tZQCS);
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ret |= of_property_read_u32(np, "tZQCL", &tim->tZQCL);
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ret |= of_property_read_u32(np, "tZQinit", &tim->tZQinit);
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ret |= of_property_read_u32(np, "tRAS-max-ns", &tim->tRAS_max_ns);
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ret |= of_property_read_u32(np, "tDQSCK-max-derated",
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&tim->tDQSCK_max_derated);
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return ret;
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}
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/**
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* of_get_ddr_timings() - extracts the ddr timings and updates no of
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* frequencies available.
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* @np_ddr: Pointer to ddr device tree node
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* @dev: Device requesting for ddr timings
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* @device_type: Type of ddr(LPDDR2 S2/S4)
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* @nr_frequencies: No of frequencies available for ddr
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* (updated by this function)
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*
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* Populates lpddr2_timings structure by extracting data from device
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* tree node. Returns pointer to populated structure. If any error
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* while populating, returns default timings provided by JEDEC.
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*/
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const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
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struct device *dev, u32 device_type, u32 *nr_frequencies)
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{
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struct lpddr2_timings *timings = NULL;
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u32 arr_sz = 0, i = 0;
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struct device_node *np_tim;
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char *tim_compat;
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switch (device_type) {
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case DDR_TYPE_LPDDR2_S2:
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case DDR_TYPE_LPDDR2_S4:
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tim_compat = "jedec,lpddr2-timings";
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break;
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default:
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dev_warn(dev, "%s: un-supported memory type\n", __func__);
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}
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for_each_child_of_node(np_ddr, np_tim)
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if (of_device_is_compatible(np_tim, tim_compat))
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arr_sz++;
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if (arr_sz)
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timings = devm_kzalloc(dev, sizeof(*timings) * arr_sz,
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GFP_KERNEL);
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if (!timings)
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goto default_timings;
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for_each_child_of_node(np_ddr, np_tim) {
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if (of_device_is_compatible(np_tim, tim_compat)) {
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if (of_do_get_timings(np_tim, &timings[i])) {
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devm_kfree(dev, timings);
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goto default_timings;
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}
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i++;
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}
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}
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*nr_frequencies = arr_sz;
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return timings;
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default_timings:
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dev_warn(dev, "%s: using default timings\n", __func__);
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*nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings);
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return lpddr2_jedec_timings;
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}
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EXPORT_SYMBOL(of_get_ddr_timings);
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