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Subject[PATCH v9 06/13] drivers: memory: extend of_memory by LPDDR3 support
Date
The patch adds AC timings information needed to support LPDDR3 and memory
controllers. The structure is used in of_memory and currently in Exynos
5422 DMC. Add parsing data needed for LPDDR3 support.
It is currently used in Exynos5422 Dynamic Memory Controller.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
drivers/memory/of_memory.c | 154 +++++++++++++++++++++++++++++++++++++
drivers/memory/of_memory.h | 18 +++++
include/memory/jedec_ddr.h | 62 +++++++++++++++
3 files changed, 234 insertions(+)

diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
index 12a61f558644..30f3a3e75063 100644
--- a/drivers/memory/of_memory.c
+++ b/drivers/memory/of_memory.c
@@ -3,6 +3,12 @@
* OpenFirmware helpers for memory drivers
*
* Copyright (C) 2012 Texas Instruments, Inc.
+ * Copyright (C) 2019 Samsung Electronics Co., Ltd.
+ *
+ * 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>
@@ -148,3 +154,151 @@ const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
return lpddr2_jedec_timings;
}
EXPORT_SYMBOL(of_get_ddr_timings);
+
+/**
+ * of_lpddr3_get_min_tck() - extract min timing values for lpddr3
+ * @np: pointer to ddr device tree node
+ * @device: device requesting for min timing values
+ *
+ * Populates the lpddr3_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 NULL.
+ */
+const struct lpddr3_min_tck *of_lpddr3_get_min_tck(struct device_node *np,
+ struct device *dev)
+{
+ int ret = 0;
+ struct lpddr3_min_tck *min;
+
+ min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
+ if (!min)
+ goto default_min_tck;
+
+ ret |= of_property_read_u32(np, "tRFC-min-tck", &min->tRFC);
+ ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
+ ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
+ ret |= of_property_read_u32(np, "tRPpb-min-tck", &min->tRPpb);
+ ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
+ ret |= of_property_read_u32(np, "tRC-min-tck", &min->tRC);
+ ret |= of_property_read_u32(np, "tRAS-min-tck", &min->tRAS);
+ ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
+ ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
+ ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
+ ret |= of_property_read_u32(np, "tW2W-C2C-min-tck", &min->tW2W_C2C);
+ ret |= of_property_read_u32(np, "tR2R-C2C-min-tck", &min->tR2R_C2C);
+ ret |= of_property_read_u32(np, "tWL-min-tck", &min->tWL);
+ ret |= of_property_read_u32(np, "tDQSCK-min-tck", &min->tDQSCK);
+ ret |= of_property_read_u32(np, "tRL-min-tck", &min->tRL);
+ ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
+ ret |= of_property_read_u32(np, "tXSR-min-tck", &min->tXSR);
+ ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
+ 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, "tMRD-min-tck", &min->tMRD);
+
+ if (ret) {
+ dev_warn(dev, "%s: errors while parsing min-tck values\n",
+ __func__);
+ 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 NULL;
+}
+EXPORT_SYMBOL(of_lpddr3_get_min_tck);
+
+static int of_lpddr3_do_get_timings(struct device_node *np,
+ struct lpddr3_timings *tim)
+{
+ int ret;
+
+ /* The 'reg' param required since DT has changed, used as 'max-freq' */
+ ret = of_property_read_u32(np, "reg", &tim->max_freq);
+ ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
+ ret |= of_property_read_u32(np, "tRFC", &tim->tRFC);
+ ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
+ ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
+ ret |= of_property_read_u32(np, "tRPpb", &tim->tRPpb);
+ ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
+ ret |= of_property_read_u32(np, "tRC", &tim->tRC);
+ ret |= of_property_read_u32(np, "tRAS", &tim->tRAS);
+ ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
+ ret |= of_property_read_u32(np, "tWR", &tim->tWR);
+ ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
+ ret |= of_property_read_u32(np, "tW2W-C2C", &tim->tW2W_C2C);
+ ret |= of_property_read_u32(np, "tR2R-C2C", &tim->tR2R_C2C);
+ ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
+ ret |= of_property_read_u32(np, "tXSR", &tim->tXSR);
+ ret |= of_property_read_u32(np, "tXP", &tim->tXP);
+ ret |= of_property_read_u32(np, "tCKE", &tim->tCKE);
+ ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
+ ret |= of_property_read_u32(np, "tMRD", &tim->tMRD);
+
+ return ret;
+}
+
+/**
+ * of_lpddr3_get_ddr_timings() - extracts the lpddr3 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
+ * @nr_frequencies: No of frequencies available for ddr
+ * (updated by this function)
+ *
+ * Populates lpddr3_timings structure by extracting data from device
+ * tree node. Returns pointer to populated structure. If any error
+ * while populating, returns NULL.
+ */
+const struct lpddr3_timings
+*of_lpddr3_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
+ u32 device_type, u32 *nr_frequencies)
+{
+ struct lpddr3_timings *timings = NULL;
+ u32 arr_sz = 0, i = 0;
+ struct device_node *np_tim;
+ char *tim_compat = NULL;
+
+ switch (device_type) {
+ case DDR_TYPE_LPDDR3:
+ tim_compat = "jedec,lpddr3-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_kcalloc(dev, arr_sz, sizeof(*timings),
+ 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_lpddr3_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 = 0;
+ return NULL;
+}
+EXPORT_SYMBOL(of_lpddr3_get_ddr_timings);
diff --git a/drivers/memory/of_memory.h b/drivers/memory/of_memory.h
index b077cc836b0b..e39ecc4c733d 100644
--- a/drivers/memory/of_memory.h
+++ b/drivers/memory/of_memory.h
@@ -14,6 +14,11 @@ extern const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
extern const struct lpddr2_timings
*of_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
u32 device_type, u32 *nr_frequencies);
+extern const struct lpddr3_min_tck
+ *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev);
+extern const struct lpddr3_timings
+ *of_lpddr3_get_ddr_timings(struct device_node *np_ddr,
+ struct device *dev, u32 device_type, u32 *nr_frequencies);
#else
static inline const struct lpddr2_min_tck
*of_get_min_tck(struct device_node *np, struct device *dev)
@@ -27,6 +32,19 @@ static inline const struct lpddr2_timings
{
return NULL;
}
+
+static inline const struct lpddr3_min_tck
+ *of_lpddr3_get_min_tck(struct device_node *np, struct device *dev)
+{
+ return NULL;
+}
+
+static inline const struct lpddr3_timings
+ *of_lpddr3_get_ddr_timings(struct device_node *np_ddr,
+ struct device *dev, u32 device_type, u32 *nr_frequencies)
+{
+ return NULL;
+}
#endif /* CONFIG_OF && CONFIG_DDR */

#endif /* __LINUX_MEMORY_OF_REG_ */
diff --git a/include/memory/jedec_ddr.h b/include/memory/jedec_ddr.h
index ddad0f870e5d..3601825f807d 100644
--- a/include/memory/jedec_ddr.h
+++ b/include/memory/jedec_ddr.h
@@ -32,6 +32,7 @@
#define DDR_TYPE_LPDDR2_S4 3
#define DDR_TYPE_LPDDR2_S2 4
#define DDR_TYPE_LPDDR2_NVM 5
+#define DDR_TYPE_LPDDR3 6

/* DDR IO width */
#define DDR_IO_WIDTH_4 1
@@ -172,4 +173,65 @@ extern const struct lpddr2_timings
lpddr2_jedec_timings[NUM_DDR_TIMING_TABLE_ENTRIES];
extern const struct lpddr2_min_tck lpddr2_jedec_min_tck;

+
+/*
+ * Structure for timings for LPDDR3 based on LPDDR2 plus additional fields.
+ * All parameters are in pico seconds(ps) unless explicitly indicated
+ * with a suffix like tRAS_max_ns below
+ */
+struct lpddr3_timings {
+ u32 max_freq;
+ u32 min_freq;
+ u32 tRFC;
+ u32 tRRD;
+ u32 tRPab;
+ u32 tRPpb;
+ u32 tRCD;
+ u32 tRC;
+ u32 tRAS;
+ u32 tWTR;
+ u32 tWR;
+ u32 tRTP;
+ u32 tW2W_C2C;
+ u32 tR2R_C2C;
+ u32 tWL;
+ u32 tDQSCK;
+ u32 tRL;
+ u32 tFAW;
+ u32 tXSR;
+ u32 tXP;
+ u32 tCKE;
+ u32 tCKESR;
+ u32 tMRD;
+};
+
+/*
+ * Min value for some parameters in terms of number of tCK cycles(nCK)
+ * Please set to zero parameters that are not valid for a given memory
+ * type
+ */
+struct lpddr3_min_tck {
+ u32 tRFC;
+ u32 tRRD;
+ u32 tRPab;
+ u32 tRPpb;
+ u32 tRCD;
+ u32 tRC;
+ u32 tRAS;
+ u32 tWTR;
+ u32 tWR;
+ u32 tRTP;
+ u32 tW2W_C2C;
+ u32 tR2R_C2C;
+ u32 tWL;
+ u32 tDQSCK;
+ u32 tRL;
+ u32 tFAW;
+ u32 tXSR;
+ u32 tXP;
+ u32 tCKE;
+ u32 tCKESR;
+ u32 tMRD;
+};
+
#endif /* __LINUX_JEDEC_DDR_H */
--
2.17.1
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