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