[PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Lukasz Luba]

Hi all,

This is v13 which makes cosmetic changes. It is based on current mainline
(v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].

The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
The driver supports Dynamic Voltage and Frequency Scaling
for the DMC and DRAM. It also provides needed timings for different
speed operations of the DRAM memory.
There is also new generic code in of_memory and headers which allows to parse
LPDDR3 memories defined in device-tree.

Here are the last changes suggested by Krzysztof during his review.
For the previous changes in older revisions please refer to [2], there is
more detailed change log.

changes:
v13:
- skipped patch with chipID changes in DT, since it is not used anymore,
- removed license comment in of_memory.c since SPDX has been merged,
- aligned comment to the current fields in the structure,
- changed printed warning when timings are not found,

Regards,
Lukasz Luba

[1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
[2] https://lkml.org/lkml/2019/7/22/251


Lukasz Luba (8):
  dt-bindings: ddr: rename lpddr2 directory
  dt-bindings: ddr: add LPDDR3 memories
  drivers: memory: extend of_memory by LPDDR3 support
  dt-bindings: memory-controllers: add Exynos5422 DMC device description
  drivers: memory: add DMC driver for Exynos5422
  ARM: dts: exynos: add syscon to clock compatible
  ARM: dts: exynos: add DMC device for exynos5422
  ARM: exynos_defconfig: enable DMC driver

 .../{lpddr2 => ddr}/lpddr2-timings.txt        |    0
 .../bindings/{lpddr2 => ddr}/lpddr2.txt       |    2 +-
 .../bindings/ddr/lpddr3-timings.txt           |   58 +
 .../devicetree/bindings/ddr/lpddr3.txt        |   97 ++
 .../memory-controllers/exynos5422-dmc.txt     |   73 +
 MAINTAINERS                                   |    8 +
 arch/arm/boot/dts/exynos5420.dtsi             |   73 +-
 arch/arm/boot/dts/exynos5422-odroid-core.dtsi |  116 ++
 arch/arm/boot/dts/exynos5800.dtsi             |    2 +-
 arch/arm/configs/exynos_defconfig             |    1 +
 drivers/memory/jedec_ddr.h                    |   61 +
 drivers/memory/of_memory.c                    |  149 ++
 drivers/memory/of_memory.h                    |   18 +
 drivers/memory/samsung/Kconfig                |   13 +
 drivers/memory/samsung/Makefile               |    1 +
 drivers/memory/samsung/exynos5422-dmc.c       | 1257 +++++++++++++++++
 16 files changed, 1926 insertions(+), 3 deletions(-)
 rename Documentation/devicetree/bindings/{lpddr2 => ddr}/lpddr2-timings.txt (100%)
 rename Documentation/devicetree/bindings/{lpddr2 => ddr}/lpddr2.txt (96%)
 create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
 create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3.txt
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
 create mode 100644 drivers/memory/samsung/exynos5422-dmc.c

-- 
2.17.1

[PATCH v13 1/8] dt-bindings: ddr: rename lpddr2 directory

[Lukasz Luba]

Change directory name to be ready for new types of memories.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 .../devicetree/bindings/{lpddr2 => ddr}/lpddr2-timings.txt      | 0
 Documentation/devicetree/bindings/{lpddr2 => ddr}/lpddr2.txt    | 2 +-
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename Documentation/devicetree/bindings/{lpddr2 => ddr}/lpddr2-timings.txt (100%)
 rename Documentation/devicetree/bindings/{lpddr2 => ddr}/lpddr2.txt (96%)

diff --git a/Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt b/Documentation/devicetree/bindings/ddr/lpddr2-timings.txt
similarity index 100%
rename from Documentation/devicetree/bindings/lpddr2/lpddr2-timings.txt
rename to Documentation/devicetree/bindings/ddr/lpddr2-timings.txt
diff --git a/Documentation/devicetree/bindings/lpddr2/lpddr2.txt b/Documentation/devicetree/bindings/ddr/lpddr2.txt
similarity index 96%
rename from Documentation/devicetree/bindings/lpddr2/lpddr2.txt
rename to Documentation/devicetree/bindings/ddr/lpddr2.txt
index 58354a075e13..ddd40121e6f6 100644
--- a/Documentation/devicetree/bindings/lpddr2/lpddr2.txt
+++ b/Documentation/devicetree/bindings/ddr/lpddr2.txt
@@ -36,7 +36,7 @@ Child nodes:
   "lpddr2-timings" provides AC timing parameters of the device for
   a given speed-bin. The user may provide the timings for as many
   speed-bins as is required. Please see Documentation/devicetree/
-  bindings/lpddr2/lpddr2-timings.txt for more information on "lpddr2-timings"
+  bindings/ddr/lpddr2-timings.txt for more information on "lpddr2-timings"
 
 Example:
 
-- 
2.17.1

[PATCH v13 2/8] dt-bindings: ddr: add LPDDR3 memories

[Lukasz Luba]

Specifies the AC timing parameters of the LPDDR3 memory device.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 .../bindings/ddr/lpddr3-timings.txt           | 58 +++++++++++
 .../devicetree/bindings/ddr/lpddr3.txt        | 97 +++++++++++++++++++
 2 files changed, 155 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
 create mode 100644 Documentation/devicetree/bindings/ddr/lpddr3.txt

diff --git a/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt b/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
new file mode 100644
index 000000000000..84705e50a3fd
--- /dev/null
+++ b/Documentation/devicetree/bindings/ddr/lpddr3-timings.txt
@@ -0,0 +1,58 @@
+* AC timing parameters of LPDDR3 memories for a given speed-bin.
+
+The structures are based on LPDDR2 and extended where needed.
+
+Required properties:
+- compatible : Should be "jedec,lpddr3-timings"
+- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
+- reg : maximum DDR clock frequency for the speed-bin. Type is <u32>
+
+Optional properties:
+
+The following properties represent AC timing parameters from the memory
+data-sheet of the device for a given speed-bin. All these properties are
+of type <u32> and the default unit is ps (pico seconds).
+- tRFC
+- tRRD
+- tRPab
+- tRPpb
+- tRCD
+- tRC
+- tRAS
+- tWTR
+- tWR
+- tRTP
+- tW2W-C2C
+- tR2R-C2C
+- tFAW
+- tXSR
+- tXP
+- tCKE
+- tCKESR
+- tMRD
+
+Example:
+
+timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
+	compatible	= "jedec,lpddr3-timings";
+	reg		= <800000000>; /* workaround: it shows max-freq */
+	min-freq	= <100000000>;
+	tRFC		= <65000>;
+	tRRD		= <6000>;
+	tRPab		= <12000>;
+	tRPpb		= <12000>;
+	tRCD		= <10000>;
+	tRC		= <33750>;
+	tRAS		= <23000>;
+	tWTR		= <3750>;
+	tWR		= <7500>;
+	tRTP		= <3750>;
+	tW2W-C2C	= <0>;
+	tR2R-C2C	= <0>;
+	tFAW		= <25000>;
+	tXSR		= <70000>;
+	tXP		= <3750>;
+	tCKE		= <3750>;
+	tCKESR		= <3750>;
+	tMRD		= <7000>;
+};
diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/ddr/lpddr3.txt
new file mode 100644
index 000000000000..3b2485b84b3f
--- /dev/null
+++ b/Documentation/devicetree/bindings/ddr/lpddr3.txt
@@ -0,0 +1,97 @@
+* LPDDR3 SDRAM memories compliant to JEDEC JESD209-3C
+
+Required properties:
+- compatible : Should be  - "jedec,lpddr3"
+- density  : <u32> representing density in Mb (Mega bits)
+- io-width : <u32> representing bus width. Possible values are 8, 16, 32, 64
+- #address-cells: Must be set to 1
+- #size-cells: Must be set to 0
+
+Optional properties:
+
+The following optional properties represent the minimum value of some AC
+timing parameters of the DDR device in terms of number of clock cycles.
+These values shall be obtained from the device data-sheet.
+- tRFC-min-tck
+- tRRD-min-tck
+- tRPab-min-tck
+- tRPpb-min-tck
+- tRCD-min-tck
+- tRC-min-tck
+- tRAS-min-tck
+- tWTR-min-tck
+- tWR-min-tck
+- tRTP-min-tck
+- tW2W-C2C-min-tck
+- tR2R-C2C-min-tck
+- tWL-min-tck
+- tDQSCK-min-tck
+- tRL-min-tck
+- tFAW-min-tck
+- tXSR-min-tck
+- tXP-min-tck
+- tCKE-min-tck
+- tCKESR-min-tck
+- tMRD-min-tck
+
+Child nodes:
+- The lpddr3 node may have one or more child nodes of type "lpddr3-timings".
+  "lpddr3-timings" provides AC timing parameters of the device for
+  a given speed-bin. Please see Documentation/devicetree/
+  bindings/ddr/lpddr3-timings.txt for more information on "lpddr3-timings"
+
+Example:
+
+samsung_K3QF2F20DB: lpddr3 {
+	compatible	= "Samsung,K3QF2F20DB", "jedec,lpddr3";
+	density		= <16384>;
+	io-width	= <32>;
+	#address-cells	= <1>;
+	#size-cells	= <0>;
+
+	tRFC-min-tck		= <17>;
+	tRRD-min-tck		= <2>;
+	tRPab-min-tck		= <2>;
+	tRPpb-min-tck		= <2>;
+	tRCD-min-tck		= <3>;
+	tRC-min-tck		= <6>;
+	tRAS-min-tck		= <5>;
+	tWTR-min-tck		= <2>;
+	tWR-min-tck		= <7>;
+	tRTP-min-tck		= <2>;
+	tW2W-C2C-min-tck	= <0>;
+	tR2R-C2C-min-tck	= <0>;
+	tWL-min-tck		= <8>;
+	tDQSCK-min-tck		= <5>;
+	tRL-min-tck		= <14>;
+	tFAW-min-tck		= <5>;
+	tXSR-min-tck		= <12>;
+	tXP-min-tck		= <2>;
+	tCKE-min-tck		= <2>;
+	tCKESR-min-tck		= <2>;
+	tMRD-min-tck		= <5>;
+
+	timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
+		compatible	= "jedec,lpddr3-timings";
+		reg		= <800000000>; /* workaround: it shows max-freq */
+		min-freq	= <100000000>;
+		tRFC		= <65000>;
+		tRRD		= <6000>;
+		tRPab		= <12000>;
+		tRPpb		= <12000>;
+		tRCD		= <10000>;
+		tRC		= <33750>;
+		tRAS		= <23000>;
+		tWTR		= <3750>;
+		tWR		= <7500>;
+		tRTP		= <3750>;
+		tW2W-C2C	= <0>;
+		tR2R-C2C	= <0>;
+		tFAW		= <25000>;
+		tXSR		= <70000>;
+		tXP		= <3750>;
+		tCKE		= <3750>;
+		tCKESR		= <3750>;
+		tMRD		= <7000>;
+	};
+}
-- 
2.17.1

[PATCH v13 3/8] drivers: memory: extend of_memory by LPDDR3 support

[Lukasz Luba]

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/jedec_ddr.h |  61 +++++++++++++++
 drivers/memory/of_memory.c | 149 +++++++++++++++++++++++++++++++++++++
 drivers/memory/of_memory.h |  18 +++++
 3 files changed, 228 insertions(+)

diff --git a/drivers/memory/jedec_ddr.h b/drivers/memory/jedec_ddr.h
index 4a21b5044ff8..e59ccbd982d0 100644
--- a/drivers/memory/jedec_ddr.h
+++ b/drivers/memory/jedec_ddr.h
@@ -29,6 +29,7 @@
 #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
@@ -169,4 +170,64 @@ 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) excluding max_freq, min_freq which
+ * are in Hz.
+ */
+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 /* __JEDEC_DDR_H */
diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
index 46539b27a3fb..71f26eac7350 100644
--- a/drivers/memory/of_memory.c
+++ b/drivers/memory/of_memory.c
@@ -3,6 +3,7 @@
  * OpenFirmware helpers for memory drivers
  *
  * Copyright (C) 2012 Texas Instruments, Inc.
+ * Copyright (C) 2019 Samsung Electronics Co., Ltd.
  */
 
 #include <linux/device.h>
@@ -149,3 +150,151 @@ 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: failed to get 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_ */
-- 
2.17.1

Re: [PATCH v13 3/8] drivers: memory: extend of_memory by LPDDR3 support

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:42:58PM +0200, Lukasz Luba wrote:
> 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.

Thanks, applied, with commit msg fixes.

Please do not write "This patch" (submitting patches mentions preferred
format). Also at this point, this is not "used currently in Exynos 5422
DMC" because there is no such driver. Just say that it is necessary for
upcoming DMC driver.

Best regards,
Krzysztof

Re: [PATCH v13 3/8] drivers: memory: extend of_memory by LPDDR3 support

[Lukasz Luba]

On 9/4/19 8:31 PM, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2019 at 12:42:58PM +0200, Lukasz Luba wrote:
>> 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.
> 
> Thanks, applied, with commit msg fixes.
> 
> Please do not write "This patch" (submitting patches mentions preferred
> format). Also at this point, this is not "used currently in Exynos 5422
> DMC" because there is no such driver. Just say that it is necessary for
> upcoming DMC driver.

OK and thank you.

Regards,
Lukasz
> 
> Best regards,
> Krzysztof
> 
> 
> 

[PATCH v13 4/8] dt-bindings: memory-controllers: add Exynos5422 DMC device description

[Lukasz Luba]

The patch adds description for DT binding for a new Exynos5422 Dynamic
Memory Controller device.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 .../memory-controllers/exynos5422-dmc.txt     | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt b/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
new file mode 100644
index 000000000000..02aeb3b5a820
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
@@ -0,0 +1,73 @@
+* Exynos5422 frequency and voltage scaling for Dynamic Memory Controller device
+
+The Samsung Exynos5422 SoC has DMC (Dynamic Memory Controller) to which the DRAM
+memory chips are connected. The driver is to monitor the controller in runtime
+and switch frequency and voltage. To monitor the usage of the controller in
+runtime, the driver uses the PPMU (Platform Performance Monitoring Unit), which
+is able to measure the current load of the memory.
+When 'userspace' governor is used for the driver, an application is able to
+switch the DMC and memory frequency.
+
+Required properties for DMC device for Exynos5422:
+- compatible: Should be "samsung,exynos5422-dmc".
+- clocks : list of clock specifiers, must contain an entry for each
+  required entry in clock-names for CLK_FOUT_SPLL, CLK_MOUT_SCLK_SPLL,
+  CLK_FF_DOUT_SPLL2, CLK_FOUT_BPLL, CLK_MOUT_BPLL, CLK_SCLK_BPLL,
+  CLK_MOUT_MX_MSPLL_CCORE, CLK_MOUT_MX_MSPLL_CCORE_PHY, CLK_MOUT_MCLK_CDREX,
+- clock-names : should include "fout_spll", "mout_sclk_spll", "ff_dout_spll2",
+  "fout_bpll", "mout_bpll", "sclk_bpll", "mout_mx_mspll_ccore",
+  "mout_mclk_cdrex"  entries
+- devfreq-events : phandles for PPMU devices connected to this DMC.
+- vdd-supply : phandle for voltage regulator which is connected.
+- reg : registers of two CDREX controllers.
+- operating-points-v2 : phandle for OPPs described in v2 definition.
+- device-handle : phandle of the connected DRAM memory device. For more
+	information please refer to documentation file:
+	Documentation/devicetree/bindings/ddr/lpddr3.txt
+- devfreq-events : phandles of the PPMU events used by the controller.
+- samsung,syscon-clk : phandle of the clock register set used by the controller,
+	these registers are used for enabling a 'pause' feature and are not
+	exposed by clock framework but they must be used in a safe way.
+	The register offsets are in the driver code and specyfic for this SoC
+	type.
+
+Example:
+
+	ppmu_dmc0_0: ppmu@10d00000 {
+		compatible = "samsung,exynos-ppmu";
+		reg = <0x10d00000 0x2000>;
+		clocks = <&clock CLK_PCLK_PPMU_DREX0_0>;
+		clock-names = "ppmu";
+		events {
+			ppmu_event_dmc0_0: ppmu-event3-dmc0_0 {
+				event-name = "ppmu-event3-dmc0_0";
+			};
+		};
+	};
+
+	dmc: memory-controller@10c20000 {
+		compatible = "samsung,exynos5422-dmc";
+		reg = <0x10c20000 0x100>, <0x10c30000 0x100>,
+		clocks = <&clock CLK_FOUT_SPLL>,
+			 <&clock CLK_MOUT_SCLK_SPLL>,
+			 <&clock CLK_FF_DOUT_SPLL2>,
+			 <&clock CLK_FOUT_BPLL>,
+			 <&clock CLK_MOUT_BPLL>,
+			 <&clock CLK_SCLK_BPLL>,
+			 <&clock CLK_MOUT_MX_MSPLL_CCORE>,
+			 <&clock CLK_MOUT_MCLK_CDREX>,
+		clock-names = "fout_spll",
+			      "mout_sclk_spll",
+			      "ff_dout_spll2",
+			      "fout_bpll",
+			      "mout_bpll",
+			      "sclk_bpll",
+			      "mout_mx_mspll_ccore",
+			      "mout_mclk_cdrex",
+		operating-points-v2 = <&dmc_opp_table>;
+		devfreq-events = <&ppmu_event3_dmc0_0>,	<&ppmu_event3_dmc0_1>,
+				<&ppmu_event3_dmc1_0>, <&ppmu_event3_dmc1_1>;
+		device-handle = <&samsung_K3QF2F20DB>;
+		vdd-supply = <&buck1_reg>;
+		samsung,syscon-clk = <&clock>;
+	};
-- 
2.17.1

[PATCH v13 5/8] drivers: memory: add DMC driver for Exynos5422

[Lukasz Luba]

This patch adds driver for Exynos5422 Dynamic Memory Controller.
The driver provides support for dynamic frequency and voltage scaling
for DMC and DRAM. It supports changing timings of DRAM running with
different frequency. There is also an algorithm to calculate timigns
based on memory description provided in DT.
The patch also contains needed MAINTAINERS file update.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 MAINTAINERS                             |    8 +
 drivers/memory/samsung/Kconfig          |   13 +
 drivers/memory/samsung/Makefile         |    1 +
 drivers/memory/samsung/exynos5422-dmc.c | 1257 +++++++++++++++++++++++
 4 files changed, 1279 insertions(+)
 create mode 100644 drivers/memory/samsung/exynos5422-dmc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 08176d64eed5..78302ccec834 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4930,6 +4930,14 @@ F:	include/linux/dma-direct.h
 F:	include/linux/dma-mapping.h
 F:	include/linux/dma-noncoherent.h
 
+DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5422
+M:	Lukasz Luba <l.luba@partner.samsung.com>
+L:	linux-pm@vger.kernel.org
+L:	linux-samsung-soc@vger.kernel.org
+S:	Maintained
+F:	drivers/memory/samsung/exynos5422-dmc.c
+F:	Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
+
 DME1737 HARDWARE MONITOR DRIVER
 M:	Juerg Haefliger <juergh@gmail.com>
 L:	linux-hwmon@vger.kernel.org
diff --git a/drivers/memory/samsung/Kconfig b/drivers/memory/samsung/Kconfig
index 79ce7ea58903..e9c3ce92350c 100644
--- a/drivers/memory/samsung/Kconfig
+++ b/drivers/memory/samsung/Kconfig
@@ -7,6 +7,19 @@ config SAMSUNG_MC
 
 if SAMSUNG_MC
 
+config EXYNOS5422_DMC
+	tristate "EXYNOS5422 Dynamic Memory Controller driver"
+	depends on ARCH_EXYNOS || (COMPILE_TEST && HAS_IOMEM)
+	select DDR
+	depends on DEVFREQ_GOV_SIMPLE_ONDEMAND
+	depends on (PM_DEVFREQ && PM_DEVFREQ_EVENT)
+	help
+	  This adds driver for Exynos5422 DMC (Dynamic Memory Controller).
+	  The driver provides support for Dynamic Voltage and Frequency Scaling in
+	  DMC and DRAM. It also supports changing timings of DRAM running with
+	  different frequency. The timings are calculated based on DT memory
+	  information.
+
 config EXYNOS_SROM
 	bool "Exynos SROM controller driver" if COMPILE_TEST
 	depends on (ARM && ARCH_EXYNOS) || (COMPILE_TEST && HAS_IOMEM)
diff --git a/drivers/memory/samsung/Makefile b/drivers/memory/samsung/Makefile
index 00587be66211..ea071be21c44 100644
--- a/drivers/memory/samsung/Makefile
+++ b/drivers/memory/samsung/Makefile
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_EXYNOS5422_DMC)	+= exynos5422-dmc.o
 obj-$(CONFIG_EXYNOS_SROM)	+= exynos-srom.o
diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
new file mode 100644
index 000000000000..8c2ec29a7d57
--- /dev/null
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -0,0 +1,1257 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd.
+ * Author: Lukasz Luba <l.luba@partner.samsung.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/devfreq.h>
+#include <linux/devfreq-event.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include "../jedec_ddr.h"
+#include "../of_memory.h"
+
+#define EXYNOS5_DREXI_TIMINGAREF		(0x0030)
+#define EXYNOS5_DREXI_TIMINGROW0		(0x0034)
+#define EXYNOS5_DREXI_TIMINGDATA0		(0x0038)
+#define EXYNOS5_DREXI_TIMINGPOWER0		(0x003C)
+#define EXYNOS5_DREXI_TIMINGROW1		(0x00E4)
+#define EXYNOS5_DREXI_TIMINGDATA1		(0x00E8)
+#define EXYNOS5_DREXI_TIMINGPOWER1		(0x00EC)
+#define CDREX_PAUSE				(0x2091c)
+#define CDREX_LPDDR3PHY_CON3			(0x20a20)
+#define CDREX_LPDDR3PHY_CLKM_SRC		(0x20700)
+#define EXYNOS5_TIMING_SET_SWI			BIT(28)
+#define USE_MX_MSPLL_TIMINGS			(1)
+#define USE_BPLL_TIMINGS			(0)
+#define EXYNOS5_AREF_NORMAL			(0x2e)
+
+/**
+ * struct dmc_opp_table - Operating level desciption
+ *
+ * Covers frequency and voltage settings of the DMC operating mode.
+ */
+struct dmc_opp_table {
+	u32 freq_hz;
+	u32 volt_uv;
+};
+
+/**
+ * struct exynos5_dmc - main structure describing DMC device
+ *
+ * The main structure for the Dynamic Memory Controller which covers clocks,
+ * memory regions, HW information, parameters and current operating mode.
+ */
+struct exynos5_dmc {
+	struct device *dev;
+	struct devfreq *df;
+	struct devfreq_simple_ondemand_data gov_data;
+	void __iomem *base_drexi0;
+	void __iomem *base_drexi1;
+	struct regmap *clk_regmap;
+	struct mutex lock;
+	unsigned long curr_rate;
+	unsigned long curr_volt;
+	unsigned long bypass_rate;
+	struct dmc_opp_table *opp;
+	struct dmc_opp_table opp_bypass;
+	int opp_count;
+	u32 timings_arr_size;
+	u32 *timing_row;
+	u32 *timing_data;
+	u32 *timing_power;
+	const struct lpddr3_timings *timings;
+	const struct lpddr3_min_tck *min_tck;
+	u32 bypass_timing_row;
+	u32 bypass_timing_data;
+	u32 bypass_timing_power;
+	struct regulator *vdd_mif;
+	struct clk *fout_spll;
+	struct clk *fout_bpll;
+	struct clk *mout_spll;
+	struct clk *mout_bpll;
+	struct clk *mout_mclk_cdrex;
+	struct clk *mout_mx_mspll_ccore;
+	struct clk *mx_mspll_ccore_phy;
+	struct clk *mout_mx_mspll_ccore_phy;
+	struct devfreq_event_dev **counter;
+	int num_counters;
+};
+
+#define TIMING_FIELD(t_name, t_bit_beg, t_bit_end) \
+	{ .name = t_name, .bit_beg = t_bit_beg, .bit_end = t_bit_end }
+
+#define TIMING_VAL2REG(timing, t_val)			\
+({							\
+		u32 __val;				\
+		__val = (t_val) << (timing)->bit_beg;	\
+		__val;					\
+})
+
+struct timing_reg {
+	char *name;
+	int bit_beg;
+	int bit_end;
+	unsigned int val;
+};
+
+static const struct timing_reg timing_row[] = {
+	TIMING_FIELD("tRFC", 24, 31),
+	TIMING_FIELD("tRRD", 20, 23),
+	TIMING_FIELD("tRP", 16, 19),
+	TIMING_FIELD("tRCD", 12, 15),
+	TIMING_FIELD("tRC", 6, 11),
+	TIMING_FIELD("tRAS", 0, 5),
+};
+
+static const struct timing_reg timing_data[] = {
+	TIMING_FIELD("tWTR", 28, 31),
+	TIMING_FIELD("tWR", 24, 27),
+	TIMING_FIELD("tRTP", 20, 23),
+	TIMING_FIELD("tW2W-C2C", 14, 14),
+	TIMING_FIELD("tR2R-C2C", 12, 12),
+	TIMING_FIELD("WL", 8, 11),
+	TIMING_FIELD("tDQSCK", 4, 7),
+	TIMING_FIELD("RL", 0, 3),
+};
+
+static const struct timing_reg timing_power[] = {
+	TIMING_FIELD("tFAW", 26, 31),
+	TIMING_FIELD("tXSR", 16, 25),
+	TIMING_FIELD("tXP", 8, 15),
+	TIMING_FIELD("tCKE", 4, 7),
+	TIMING_FIELD("tMRD", 0, 3),
+};
+
+#define TIMING_COUNT (ARRAY_SIZE(timing_row) + ARRAY_SIZE(timing_data) + \
+		      ARRAY_SIZE(timing_power))
+
+static int exynos5_counters_set_event(struct exynos5_dmc *dmc)
+{
+	int i, ret;
+
+	for (i = 0; i < dmc->num_counters; i++) {
+		if (!dmc->counter[i])
+			continue;
+		ret = devfreq_event_set_event(dmc->counter[i]);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
+static int exynos5_counters_enable_edev(struct exynos5_dmc *dmc)
+{
+	int i, ret;
+
+	for (i = 0; i < dmc->num_counters; i++) {
+		if (!dmc->counter[i])
+			continue;
+		ret = devfreq_event_enable_edev(dmc->counter[i]);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
+static int exynos5_counters_disable_edev(struct exynos5_dmc *dmc)
+{
+	int i, ret;
+
+	for (i = 0; i < dmc->num_counters; i++) {
+		if (!dmc->counter[i])
+			continue;
+		ret = devfreq_event_disable_edev(dmc->counter[i]);
+		if (ret < 0)
+			return ret;
+	}
+	return 0;
+}
+
+/**
+ * find_target_freq_id() - Finds requested frequency in local DMC configuration
+ * @dmc:	device for which the information is checked
+ * @target_rate:	requested frequency in KHz
+ *
+ * Seeks in the local DMC driver structure for the requested frequency value
+ * and returns index or error value.
+ */
+static int find_target_freq_idx(struct exynos5_dmc *dmc,
+				unsigned long target_rate)
+{
+	int i;
+
+	for (i = dmc->opp_count - 1; i >= 0; i--)
+		if (dmc->opp[i].freq_hz <= target_rate)
+			return i;
+
+	return -EINVAL;
+}
+
+/**
+ * exynos5_switch_timing_regs() - Changes bank register set for DRAM timings
+ * @dmc:	device for which the new settings is going to be applied
+ * @set:	boolean variable passing set value
+ *
+ * Changes the register set, which holds timing parameters.
+ * There is two register sets: 0 and 1. The register set 0
+ * is used in normal operation when the clock is provided from main PLL.
+ * The bank register set 1 is used when the main PLL frequency is going to be
+ * changed and the clock is taken from alternative, stable source.
+ * This function switches between these banks according to the
+ * currently used clock source.
+ */
+static void exynos5_switch_timing_regs(struct exynos5_dmc *dmc, bool set)
+{
+	unsigned int reg;
+	int ret;
+
+	ret = regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, &reg);
+
+	if (set)
+		reg |= EXYNOS5_TIMING_SET_SWI;
+	else
+		reg &= ~EXYNOS5_TIMING_SET_SWI;
+
+	regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CON3, reg);
+}
+
+/**
+ * exynos5_init_freq_table() - Initialized PM OPP framework
+ * @dmc:	DMC device for which the frequencies are used for OPP init
+ * @profile:	devfreq device's profile
+ *
+ * Populate the devfreq device's OPP table based on current frequency, voltage.
+ */
+static int exynos5_init_freq_table(struct exynos5_dmc *dmc,
+				   struct devfreq_dev_profile *profile)
+{
+	int i, ret;
+	int idx;
+	unsigned long freq;
+
+	ret = dev_pm_opp_of_add_table(dmc->dev);
+	if (ret < 0) {
+		dev_err(dmc->dev, "Failed to get OPP table\n");
+		return ret;
+	}
+
+	dmc->opp_count = dev_pm_opp_get_opp_count(dmc->dev);
+
+	dmc->opp = devm_kmalloc_array(dmc->dev, dmc->opp_count,
+				      sizeof(struct dmc_opp_table), GFP_KERNEL);
+	if (!dmc->opp)
+		goto err_opp;
+
+	idx = dmc->opp_count - 1;
+	for (i = 0, freq = ULONG_MAX; i < dmc->opp_count; i++, freq--) {
+		struct dev_pm_opp *opp;
+
+		opp = dev_pm_opp_find_freq_floor(dmc->dev, &freq);
+		if (IS_ERR(opp))
+			goto err_free_tables;
+
+		dmc->opp[idx - i].freq_hz = freq;
+		dmc->opp[idx - i].volt_uv = dev_pm_opp_get_voltage(opp);
+
+		dev_pm_opp_put(opp);
+	}
+
+	return 0;
+
+err_free_tables:
+	kfree(dmc->opp);
+err_opp:
+	dev_pm_opp_of_remove_table(dmc->dev);
+
+	return -EINVAL;
+}
+
+/**
+ * exynos5_set_bypass_dram_timings() - Low-level changes of the DRAM timings
+ * @dmc:	device for which the new settings is going to be applied
+ * @param:	DRAM parameters which passes timing data
+ *
+ * Low-level function for changing timings for DRAM memory clocking from
+ * 'bypass' clock source (fixed frequency @400MHz).
+ * It uses timing bank registers set 1.
+ */
+static void exynos5_set_bypass_dram_timings(struct exynos5_dmc *dmc)
+{
+	writel(EXYNOS5_AREF_NORMAL,
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF);
+
+	writel(dmc->bypass_timing_row,
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW1);
+	writel(dmc->bypass_timing_row,
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW1);
+	writel(dmc->bypass_timing_data,
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA1);
+	writel(dmc->bypass_timing_data,
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA1);
+	writel(dmc->bypass_timing_power,
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER1);
+	writel(dmc->bypass_timing_power,
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER1);
+}
+
+/**
+ * exynos5_dram_change_timings() - Low-level changes of the DRAM final timings
+ * @dmc:	device for which the new settings is going to be applied
+ * @target_rate:	target frequency of the DMC
+ *
+ * Low-level function for changing timings for DRAM memory operating from main
+ * clock source (BPLL), which can have different frequencies. Thus, each
+ * frequency must have corresponding timings register values in order to keep
+ * the needed delays.
+ * It uses timing bank registers set 0.
+ */
+static int exynos5_dram_change_timings(struct exynos5_dmc *dmc,
+				       unsigned long target_rate)
+{
+	int idx;
+
+	for (idx = dmc->opp_count - 1; idx >= 0; idx--)
+		if (dmc->opp[idx].freq_hz <= target_rate)
+			break;
+
+	if (idx < 0)
+		return -EINVAL;
+
+	writel(EXYNOS5_AREF_NORMAL,
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGAREF);
+
+	writel(dmc->timing_row[idx],
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGROW0);
+	writel(dmc->timing_row[idx],
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGROW0);
+	writel(dmc->timing_data[idx],
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGDATA0);
+	writel(dmc->timing_data[idx],
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGDATA0);
+	writel(dmc->timing_power[idx],
+	       dmc->base_drexi0 + EXYNOS5_DREXI_TIMINGPOWER0);
+	writel(dmc->timing_power[idx],
+	       dmc->base_drexi1 + EXYNOS5_DREXI_TIMINGPOWER0);
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_align_target_voltage() - Sets the final voltage for the DMC
+ * @dmc:	device for which it is going to be set
+ * @target_volt:	new voltage which is chosen to be final
+ *
+ * Function tries to align voltage to the safe level for 'normal' mode.
+ * It checks the need of higher voltage and changes the value. The target
+ * voltage might be lower that currently set and still the system will be
+ * stable.
+ */
+static int exynos5_dmc_align_target_voltage(struct exynos5_dmc *dmc,
+					    unsigned long target_volt)
+{
+	int ret = 0;
+
+	if (dmc->curr_volt <= target_volt)
+		return 0;
+
+	ret = regulator_set_voltage(dmc->vdd_mif, target_volt,
+				    target_volt);
+	if (!ret)
+		dmc->curr_volt = target_volt;
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_align_bypass_voltage() - Sets the voltage for the DMC
+ * @dmc:	device for which it is going to be set
+ * @target_volt:	new voltage which is chosen to be final
+ *
+ * Function tries to align voltage to the safe level for the 'bypass' mode.
+ * It checks the need of higher voltage and changes the value.
+ * The target voltage must not be less than currently needed, because
+ * for current frequency the device might become unstable.
+ */
+static int exynos5_dmc_align_bypass_voltage(struct exynos5_dmc *dmc,
+					    unsigned long target_volt)
+{
+	int ret = 0;
+	unsigned long bypass_volt = dmc->opp_bypass.volt_uv;
+
+	target_volt = max(bypass_volt, target_volt);
+
+	if (dmc->curr_volt >= target_volt)
+		return 0;
+
+	ret = regulator_set_voltage(dmc->vdd_mif, target_volt,
+				    target_volt);
+	if (!ret)
+		dmc->curr_volt = target_volt;
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_align_bypass_dram_timings() - Chooses and sets DRAM timings
+ * @dmc:	device for which it is going to be set
+ * @target_rate:	new frequency which is chosen to be final
+ *
+ * Function changes the DRAM timings for the temporary 'bypass' mode.
+ */
+static int exynos5_dmc_align_bypass_dram_timings(struct exynos5_dmc *dmc,
+						 unsigned long target_rate)
+{
+	int idx = find_target_freq_idx(dmc, target_rate);
+
+	if (idx < 0)
+		return -EINVAL;
+
+	exynos5_set_bypass_dram_timings(dmc);
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_switch_to_bypass_configuration() - Switching to temporary clock
+ * @dmc:	DMC device for which the switching is going to happen
+ * @target_rate:	new frequency which is going to be set as a final
+ * @target_volt:	new voltage which is going to be set as a final
+ *
+ * Function configures DMC and clocks for operating in temporary 'bypass' mode.
+ * This mode is used only temporary but if required, changes voltage and timings
+ * for DRAM chips. It switches the main clock to stable clock source for the
+ * period of the main PLL reconfiguration.
+ */
+static int
+exynos5_dmc_switch_to_bypass_configuration(struct exynos5_dmc *dmc,
+					   unsigned long target_rate,
+					   unsigned long target_volt)
+{
+	int ret;
+
+	/*
+	 * Having higher voltage for a particular frequency does not harm
+	 * the chip. Use it for the temporary frequency change when one
+	 * voltage manipulation might be avoided.
+	 */
+	ret = exynos5_dmc_align_bypass_voltage(dmc, target_volt);
+	if (ret)
+		return ret;
+
+	/*
+	 * Longer delays for DRAM does not cause crash, the opposite does.
+	 */
+	ret = exynos5_dmc_align_bypass_dram_timings(dmc, target_rate);
+	if (ret)
+		return ret;
+
+	/*
+	 * Delays are long enough, so use them for the new coming clock.
+	 */
+	exynos5_switch_timing_regs(dmc, USE_MX_MSPLL_TIMINGS);
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_change_freq_and_volt() - Changes voltage and frequency of the DMC
+ * using safe procedure
+ * @dmc:	device for which the frequency is going to be changed
+ * @target_rate:	requested new frequency
+ * @target_volt:	requested voltage which corresponds to the new frequency
+ *
+ * The DMC frequency change procedure requires a few steps.
+ * The main requirement is to change the clock source in the clk mux
+ * for the time of main clock PLL locking. The assumption is that the
+ * alternative clock source set as parent is stable.
+ * The second parent's clock frequency is fixed to 400MHz, it is named 'bypass'
+ * clock. This requires alignment in DRAM timing parameters for the new
+ * T-period. There is two bank sets for keeping DRAM
+ * timings: set 0 and set 1. The set 0 is used when main clock source is
+ * chosen. The 2nd set of regs is used for 'bypass' clock. Switching between
+ * the two bank sets is part of the process.
+ * The voltage must also be aligned to the minimum required level. There is
+ * this intermediate step with switching to 'bypass' parent clock source.
+ * if the old voltage is lower, it requires an increase of the voltage level.
+ * The complexity of the voltage manipulation is hidden in low level function.
+ * In this function there is last alignment of the voltage level at the end.
+ */
+static int
+exynos5_dmc_change_freq_and_volt(struct exynos5_dmc *dmc,
+				 unsigned long target_rate,
+				 unsigned long target_volt)
+{
+	int ret;
+
+	ret = exynos5_dmc_switch_to_bypass_configuration(dmc, target_rate,
+							 target_volt);
+	if (ret)
+		return ret;
+
+	/*
+	 * Voltage is set at least to a level needed for this frequency,
+	 * so switching clock source is safe now.
+	 */
+	clk_prepare_enable(dmc->fout_spll);
+	clk_prepare_enable(dmc->mout_spll);
+	clk_prepare_enable(dmc->mout_mx_mspll_ccore);
+
+	ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_mx_mspll_ccore);
+	if (ret)
+		goto disable_clocks;
+
+	/*
+	 * We are safe to increase the timings for current bypass frequency.
+	 * Thanks to this the settings will be ready for the upcoming clock
+	 * source change.
+	 */
+	exynos5_dram_change_timings(dmc, target_rate);
+
+	clk_set_rate(dmc->fout_bpll, target_rate);
+
+	exynos5_switch_timing_regs(dmc, USE_BPLL_TIMINGS);
+
+	ret = clk_set_parent(dmc->mout_mclk_cdrex, dmc->mout_bpll);
+	if (ret)
+		goto disable_clocks;
+
+	/*
+	 * Make sure if the voltage is not from 'bypass' settings and align to
+	 * the right level for power efficiency.
+	 */
+	ret = exynos5_dmc_align_target_voltage(dmc, target_volt);
+
+disable_clocks:
+	clk_disable_unprepare(dmc->mout_mx_mspll_ccore);
+	clk_disable_unprepare(dmc->mout_spll);
+	clk_disable_unprepare(dmc->fout_spll);
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_get_volt_freq() - Gets the frequency and voltage from the OPP
+ * table.
+ * @dmc:	device for which the frequency is going to be changed
+ * @freq:       requested frequency in KHz
+ * @target_rate:	returned frequency which is the same or lower than
+ *			requested
+ * @target_volt:	returned voltage which corresponds to the returned
+ *			frequency
+ *
+ * Function gets requested frequency and checks OPP framework for needed
+ * frequency and voltage. It populates the values 'target_rate' and
+ * 'target_volt' or returns error value when OPP framework fails.
+ */
+static int exynos5_dmc_get_volt_freq(struct exynos5_dmc *dmc,
+				     unsigned long *freq,
+				     unsigned long *target_rate,
+				     unsigned long *target_volt, u32 flags)
+{
+	struct dev_pm_opp *opp;
+
+	opp = devfreq_recommended_opp(dmc->dev, freq, flags);
+	if (IS_ERR(opp))
+		return PTR_ERR(opp);
+
+	*target_rate = dev_pm_opp_get_freq(opp);
+	*target_volt = dev_pm_opp_get_voltage(opp);
+	dev_pm_opp_put(opp);
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_target() - Function responsible for changing frequency of DMC
+ * @dev:	device for which the frequency is going to be changed
+ * @freq:	requested frequency in KHz
+ * @flags:	flags provided for this frequency change request
+ *
+ * An entry function provided to the devfreq framework which provides frequency
+ * change of the DMC. The function gets the possible rate from OPP table based
+ * on requested frequency. It calls the next function responsible for the
+ * frequency and voltage change. In case of failure, does not set 'curr_rate'
+ * and returns error value to the framework.
+ */
+static int exynos5_dmc_target(struct device *dev, unsigned long *freq,
+			      u32 flags)
+{
+	struct exynos5_dmc *dmc = dev_get_drvdata(dev);
+	unsigned long target_rate = 0;
+	unsigned long target_volt = 0;
+	int ret;
+
+	ret = exynos5_dmc_get_volt_freq(dmc, freq, &target_rate, &target_volt,
+					flags);
+
+	if (ret)
+		return ret;
+
+	if (target_rate == dmc->curr_rate)
+		return 0;
+
+	mutex_lock(&dmc->lock);
+
+	ret = exynos5_dmc_change_freq_and_volt(dmc, target_rate, target_volt);
+
+	if (ret) {
+		mutex_unlock(&dmc->lock);
+		return ret;
+	}
+
+	dmc->curr_rate = target_rate;
+
+	mutex_unlock(&dmc->lock);
+	return 0;
+}
+
+/**
+ * exynos5_counters_get() - Gets the performance counters values.
+ * @dmc:	device for which the counters are going to be checked
+ * @load_count:	variable which is populated with counter value
+ * @total_count:	variable which is used as 'wall clock' reference
+ *
+ * Function which provides performance counters values. It sums up counters for
+ * two DMC channels. The 'total_count' is used as a reference and max value.
+ * The ratio 'load_count/total_count' shows the busy percentage [0%, 100%].
+ */
+static int exynos5_counters_get(struct exynos5_dmc *dmc,
+				unsigned long *load_count,
+				unsigned long *total_count)
+{
+	unsigned long total = 0;
+	struct devfreq_event_data event;
+	int ret, i;
+
+	*load_count = 0;
+
+	/* Take into account only read+write counters, but stop all */
+	for (i = 0; i < dmc->num_counters; i++) {
+		if (!dmc->counter[i])
+			continue;
+
+		ret = devfreq_event_get_event(dmc->counter[i], &event);
+		if (ret < 0)
+			return ret;
+
+		*load_count += event.load_count;
+
+		if (total < event.total_count)
+			total = event.total_count;
+	}
+
+	*total_count = total;
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_get_status() - Read current DMC performance statistics.
+ * @dev:	device for which the statistics are requested
+ * @stat:	structure which has statistic fields
+ *
+ * Function reads the DMC performance counters and calculates 'busy_time'
+ * and 'total_time'. To protect from overflow, the values are shifted right
+ * by 10. After read out the counters are setup to count again.
+ */
+static int exynos5_dmc_get_status(struct device *dev,
+				  struct devfreq_dev_status *stat)
+{
+	struct exynos5_dmc *dmc = dev_get_drvdata(dev);
+	unsigned long load, total;
+	int ret;
+
+	ret = exynos5_counters_get(dmc, &load, &total);
+	if (ret < 0)
+		return -EINVAL;
+
+	/* To protect from overflow in calculation ratios, divide by 1024 */
+	stat->busy_time = load >> 10;
+	stat->total_time = total >> 10;
+
+	ret = exynos5_counters_set_event(dmc);
+	if (ret < 0) {
+		dev_err(dev, "could not set event counter\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_get_cur_freq() - Function returns current DMC frequency
+ * @dev:	device for which the framework checks operating frequency
+ * @freq:	returned frequency value
+ *
+ * It returns the currently used frequency of the DMC. The real operating
+ * frequency might be lower when the clock source value could not be divided
+ * to the requested value.
+ */
+static int exynos5_dmc_get_cur_freq(struct device *dev, unsigned long *freq)
+{
+	struct exynos5_dmc *dmc = dev_get_drvdata(dev);
+
+	mutex_lock(&dmc->lock);
+	*freq = dmc->curr_rate;
+	mutex_unlock(&dmc->lock);
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_df_profile - Devfreq governor's profile structure
+ *
+ * It provides to the devfreq framework needed functions and polling period.
+ */
+static struct devfreq_dev_profile exynos5_dmc_df_profile = {
+	.polling_ms = 500,
+	.target = exynos5_dmc_target,
+	.get_dev_status = exynos5_dmc_get_status,
+	.get_cur_freq = exynos5_dmc_get_cur_freq,
+};
+
+/**
+ * exynos5_dmc_align_initial_frequency() - Align initial frequency value
+ * @dmc:	device for which the frequency is going to be set
+ * @bootloader_init_freq:	initial frequency set by the bootloader in KHz
+ *
+ * The initial bootloader frequency, which is present during boot, might be
+ * different that supported frequency values in the driver. It is possible
+ * due to different PLL settings or used PLL as a source.
+ * This function provides the 'initial_freq' for the devfreq framework
+ * statistics engine which supports only registered values. Thus, some alignment
+ * must be made.
+ */
+unsigned long
+exynos5_dmc_align_init_freq(struct exynos5_dmc *dmc,
+			    unsigned long bootloader_init_freq)
+{
+	unsigned long aligned_freq;
+	int idx;
+
+	idx = find_target_freq_idx(dmc, bootloader_init_freq);
+	if (idx >= 0)
+		aligned_freq = dmc->opp[idx].freq_hz;
+	else
+		aligned_freq = dmc->opp[dmc->opp_count - 1].freq_hz;
+
+	return aligned_freq;
+}
+
+/**
+ * create_timings_aligned() - Create register values and align with standard
+ * @dmc:	device for which the frequency is going to be set
+ * @idx:	speed bin in the OPP table
+ * @clk_period_ps:	the period of the clock, known as tCK
+ *
+ * The function calculates timings and creates a register value ready for
+ * a frequency transition. The register contains a few timings. They are
+ * shifted by a known offset. The timing value is calculated based on memory
+ * specyfication: minimal time required and minimal cycles required.
+ */
+static int create_timings_aligned(struct exynos5_dmc *dmc, u32 *reg_timing_row,
+				  u32 *reg_timing_data, u32 *reg_timing_power,
+				  u32 clk_period_ps)
+{
+	u32 val;
+	const struct timing_reg *reg;
+
+	if (clk_period_ps == 0)
+		return -EINVAL;
+
+	*reg_timing_row = 0;
+	*reg_timing_data = 0;
+	*reg_timing_power = 0;
+
+	val = dmc->timings->tRFC / clk_period_ps;
+	val += dmc->timings->tRFC % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRFC);
+	reg = &timing_row[0];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRRD / clk_period_ps;
+	val += dmc->timings->tRRD % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRRD);
+	reg = &timing_row[1];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRPab / clk_period_ps;
+	val += dmc->timings->tRPab % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRPab);
+	reg = &timing_row[2];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRCD / clk_period_ps;
+	val += dmc->timings->tRCD % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRCD);
+	reg = &timing_row[3];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRC / clk_period_ps;
+	val += dmc->timings->tRC % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRC);
+	reg = &timing_row[4];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRAS / clk_period_ps;
+	val += dmc->timings->tRAS % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRAS);
+	reg = &timing_row[5];
+	*reg_timing_row |= TIMING_VAL2REG(reg, val);
+
+	/* data related timings */
+	val = dmc->timings->tWTR / clk_period_ps;
+	val += dmc->timings->tWTR % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tWTR);
+	reg = &timing_data[0];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tWR / clk_period_ps;
+	val += dmc->timings->tWR % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tWR);
+	reg = &timing_data[1];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRTP / clk_period_ps;
+	val += dmc->timings->tRTP % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRTP);
+	reg = &timing_data[2];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tW2W_C2C / clk_period_ps;
+	val += dmc->timings->tW2W_C2C % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tW2W_C2C);
+	reg = &timing_data[3];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tR2R_C2C / clk_period_ps;
+	val += dmc->timings->tR2R_C2C % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tR2R_C2C);
+	reg = &timing_data[4];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tWL / clk_period_ps;
+	val += dmc->timings->tWL % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tWL);
+	reg = &timing_data[5];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tDQSCK / clk_period_ps;
+	val += dmc->timings->tDQSCK % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tDQSCK);
+	reg = &timing_data[6];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tRL / clk_period_ps;
+	val += dmc->timings->tRL % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tRL);
+	reg = &timing_data[7];
+	*reg_timing_data |= TIMING_VAL2REG(reg, val);
+
+	/* power related timings */
+	val = dmc->timings->tFAW / clk_period_ps;
+	val += dmc->timings->tFAW % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tXP);
+	reg = &timing_power[0];
+	*reg_timing_power |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tXSR / clk_period_ps;
+	val += dmc->timings->tXSR % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tXSR);
+	reg = &timing_power[1];
+	*reg_timing_power |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tXP / clk_period_ps;
+	val += dmc->timings->tXP % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tXP);
+	reg = &timing_power[2];
+	*reg_timing_power |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tCKE / clk_period_ps;
+	val += dmc->timings->tCKE % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tCKE);
+	reg = &timing_power[3];
+	*reg_timing_power |= TIMING_VAL2REG(reg, val);
+
+	val = dmc->timings->tMRD / clk_period_ps;
+	val += dmc->timings->tMRD % clk_period_ps ? 1 : 0;
+	val = max(val, dmc->min_tck->tMRD);
+	reg = &timing_power[4];
+	*reg_timing_power |= TIMING_VAL2REG(reg, val);
+
+	return 0;
+}
+
+/**
+ * of_get_dram_timings() - helper function for parsing DT settings for DRAM
+ * @dmc:        device for which the frequency is going to be set
+ *
+ * The function parses DT entries with DRAM information.
+ */
+static int of_get_dram_timings(struct exynos5_dmc *dmc)
+{
+	int ret = 0;
+	int idx;
+	struct device_node *np_ddr;
+	u32 freq_mhz, clk_period_ps;
+
+	np_ddr = of_parse_phandle(dmc->dev->of_node, "device-handle", 0);
+	if (!np_ddr) {
+		dev_warn(dmc->dev, "could not find 'device-handle' in DT\n");
+		return -EINVAL;
+	}
+
+	dmc->timing_row = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
+					     sizeof(u32), GFP_KERNEL);
+	if (!dmc->timing_row)
+		return -ENOMEM;
+
+	dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
+					      sizeof(u32), GFP_KERNEL);
+	if (!dmc->timing_data)
+		return -ENOMEM;
+
+	dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
+					       sizeof(u32), GFP_KERNEL);
+	if (!dmc->timing_power)
+		return -ENOMEM;
+
+	dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev,
+						 DDR_TYPE_LPDDR3,
+						 &dmc->timings_arr_size);
+	if (!dmc->timings) {
+		of_node_put(np_ddr);
+		dev_warn(dmc->dev, "could not get timings from DT\n");
+		return -EINVAL;
+	}
+
+	dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev);
+	if (!dmc->min_tck) {
+		of_node_put(np_ddr);
+		dev_warn(dmc->dev, "could not get tck from DT\n");
+		return -EINVAL;
+	}
+
+	/* Sorted array of OPPs with frequency ascending */
+	for (idx = 0; idx < dmc->opp_count; idx++) {
+		freq_mhz = dmc->opp[idx].freq_hz / 1000000;
+		clk_period_ps = 1000000 / freq_mhz;
+
+		ret = create_timings_aligned(dmc, &dmc->timing_row[idx],
+					     &dmc->timing_data[idx],
+					     &dmc->timing_power[idx],
+					     clk_period_ps);
+	}
+
+	of_node_put(np_ddr);
+
+	/* Take the highest frequency's timings as 'bypass' */
+	dmc->bypass_timing_row = dmc->timing_row[idx - 1];
+	dmc->bypass_timing_data = dmc->timing_data[idx - 1];
+	dmc->bypass_timing_power = dmc->timing_power[idx - 1];
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_init_clks() - Initialize clocks needed for DMC operation.
+ * @dmc:	DMC structure containing needed fields
+ *
+ * Get the needed clocks defined in DT device, enable and set the right parents.
+ * Read current frequency and initialize the initial rate for governor.
+ */
+static int exynos5_dmc_init_clks(struct exynos5_dmc *dmc)
+{
+	int ret;
+	unsigned long target_volt = 0;
+	unsigned long target_rate = 0;
+	unsigned int tmp;
+
+	dmc->fout_spll = devm_clk_get(dmc->dev, "fout_spll");
+	if (IS_ERR(dmc->fout_spll))
+		return PTR_ERR(dmc->fout_spll);
+
+	dmc->fout_bpll = devm_clk_get(dmc->dev, "fout_bpll");
+	if (IS_ERR(dmc->fout_bpll))
+		return PTR_ERR(dmc->fout_bpll);
+
+	dmc->mout_mclk_cdrex = devm_clk_get(dmc->dev, "mout_mclk_cdrex");
+	if (IS_ERR(dmc->mout_mclk_cdrex))
+		return PTR_ERR(dmc->mout_mclk_cdrex);
+
+	dmc->mout_bpll = devm_clk_get(dmc->dev, "mout_bpll");
+	if (IS_ERR(dmc->mout_bpll))
+		return PTR_ERR(dmc->mout_bpll);
+
+	dmc->mout_mx_mspll_ccore = devm_clk_get(dmc->dev,
+						"mout_mx_mspll_ccore");
+	if (IS_ERR(dmc->mout_mx_mspll_ccore))
+		return PTR_ERR(dmc->mout_mx_mspll_ccore);
+
+	dmc->mout_spll = devm_clk_get(dmc->dev, "ff_dout_spll2");
+	if (IS_ERR(dmc->mout_spll)) {
+		dmc->mout_spll = devm_clk_get(dmc->dev, "mout_sclk_spll");
+		if (IS_ERR(dmc->mout_spll))
+			return PTR_ERR(dmc->mout_spll);
+	}
+
+	/*
+	 * Convert frequency to KHz values and set it for the governor.
+	 */
+	dmc->curr_rate = clk_get_rate(dmc->mout_mclk_cdrex);
+	dmc->curr_rate = exynos5_dmc_align_init_freq(dmc, dmc->curr_rate);
+	exynos5_dmc_df_profile.initial_freq = dmc->curr_rate;
+
+	ret = exynos5_dmc_get_volt_freq(dmc, &dmc->curr_rate, &target_rate,
+					&target_volt, 0);
+	if (ret)
+		return ret;
+
+	dmc->curr_volt = target_volt;
+
+	clk_set_parent(dmc->mout_mx_mspll_ccore, dmc->mout_spll);
+
+	dmc->bypass_rate = clk_get_rate(dmc->mout_mx_mspll_ccore);
+
+	clk_prepare_enable(dmc->fout_bpll);
+	clk_prepare_enable(dmc->mout_bpll);
+
+	/*
+	 * Some bootloaders do not set clock routes correctly.
+	 * Stop one path in clocks to PHY.
+	 */
+	regmap_read(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, &tmp);
+	tmp &= ~(BIT(1) | BIT(0));
+	regmap_write(dmc->clk_regmap, CDREX_LPDDR3PHY_CLKM_SRC, tmp);
+
+	return 0;
+}
+
+/**
+ * exynos5_performance_counters_init() - Initializes performance DMC's counters
+ * @dmc:	DMC for which it does the setup
+ *
+ * Initialization of performance counters in DMC for estimating usage.
+ * The counter's values are used for calculation of a memory bandwidth and based
+ * on that the governor changes the frequency.
+ * The counters are not used when the governor is GOVERNOR_USERSPACE.
+ */
+static int exynos5_performance_counters_init(struct exynos5_dmc *dmc)
+{
+	int counters_size;
+	int ret, i;
+
+	dmc->num_counters = devfreq_event_get_edev_count(dmc->dev);
+	if (dmc->num_counters < 0) {
+		dev_err(dmc->dev, "could not get devfreq-event counters\n");
+		return dmc->num_counters;
+	}
+
+	counters_size = sizeof(struct devfreq_event_dev) * dmc->num_counters;
+	dmc->counter = devm_kzalloc(dmc->dev, counters_size, GFP_KERNEL);
+	if (!dmc->counter)
+		return -ENOMEM;
+
+	for (i = 0; i < dmc->num_counters; i++) {
+		dmc->counter[i] =
+			devfreq_event_get_edev_by_phandle(dmc->dev, i);
+		if (IS_ERR_OR_NULL(dmc->counter[i]))
+			return -EPROBE_DEFER;
+	}
+
+	ret = exynos5_counters_enable_edev(dmc);
+	if (ret < 0) {
+		dev_err(dmc->dev, "could not enable event counter\n");
+		return ret;
+	}
+
+	ret = exynos5_counters_set_event(dmc);
+	if (ret < 0) {
+		exynos5_counters_disable_edev(dmc);
+		dev_err(dmc->dev, "counld not set event counter\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_set_pause_on_switching() - Controls a pause feature in DMC
+ * @dmc:	device which is used for changing this feature
+ * @set:	a boolean state passing enable/disable request
+ *
+ * There is a need of pausing DREX DMC when divider or MUX in clock tree
+ * changes its configuration. In such situation access to the memory is blocked
+ * in DMC automatically. This feature is used when clock frequency change
+ * request appears and touches clock tree.
+ */
+static inline int exynos5_dmc_set_pause_on_switching(struct exynos5_dmc *dmc)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(dmc->clk_regmap, CDREX_PAUSE, &val);
+	if (ret)
+		return ret;
+
+	val |= 1UL;
+	regmap_write(dmc->clk_regmap, CDREX_PAUSE, val);
+
+	return 0;
+}
+
+/**
+ * exynos5_dmc_probe() - Probe function for the DMC driver
+ * @pdev:	platform device for which the driver is going to be initialized
+ *
+ * Initialize basic components: clocks, regulators, performance counters, etc.
+ * Read out product version and based on the information setup
+ * internal structures for the controller (frequency and voltage) and for DRAM
+ * memory parameters: timings for each operating frequency.
+ * Register new devfreq device for controlling DVFS of the DMC.
+ */
+static int exynos5_dmc_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct exynos5_dmc *dmc;
+	struct resource *res;
+
+	dmc = devm_kzalloc(dev, sizeof(*dmc), GFP_KERNEL);
+	if (!dmc)
+		return -ENOMEM;
+
+	mutex_init(&dmc->lock);
+
+	dmc->dev = dev;
+	platform_set_drvdata(pdev, dmc);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dmc->base_drexi0 = devm_ioremap_resource(dev, res);
+	if (IS_ERR(dmc->base_drexi0))
+		return PTR_ERR(dmc->base_drexi0);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	dmc->base_drexi1 = devm_ioremap_resource(dev, res);
+	if (IS_ERR(dmc->base_drexi1))
+		return PTR_ERR(dmc->base_drexi1);
+
+	dmc->clk_regmap = syscon_regmap_lookup_by_phandle(np,
+				"samsung,syscon-clk");
+	if (IS_ERR(dmc->clk_regmap))
+		return PTR_ERR(dmc->clk_regmap);
+
+	ret = exynos5_init_freq_table(dmc, &exynos5_dmc_df_profile);
+	if (ret) {
+		dev_warn(dev, "couldn't initialize frequency settings\n");
+		return ret;
+	}
+
+	dmc->vdd_mif = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(dmc->vdd_mif)) {
+		ret = PTR_ERR(dmc->vdd_mif);
+		return ret;
+	}
+
+	ret = exynos5_dmc_init_clks(dmc);
+	if (ret)
+		return ret;
+
+	ret = of_get_dram_timings(dmc);
+	if (ret) {
+		dev_warn(dev, "couldn't initialize timings settings\n");
+		goto remove_clocks;
+	}
+
+	ret = exynos5_performance_counters_init(dmc);
+	if (ret) {
+		dev_warn(dev, "couldn't probe performance counters\n");
+		goto remove_clocks;
+	}
+
+	ret = exynos5_dmc_set_pause_on_switching(dmc);
+	if (ret) {
+		dev_warn(dev, "couldn't get access to PAUSE register\n");
+		goto err_devfreq_add;
+	}
+
+	/*
+	 * Setup default thresholds for the devfreq governor.
+	 * The values are chosen based on experiments.
+	 */
+	dmc->gov_data.upthreshold = 30;
+	dmc->gov_data.downdifferential = 5;
+
+	dmc->df = devm_devfreq_add_device(dev, &exynos5_dmc_df_profile,
+					  DEVFREQ_GOV_SIMPLE_ONDEMAND,
+					  &dmc->gov_data);
+
+	if (IS_ERR(dmc->df)) {
+		ret = PTR_ERR(dmc->df);
+		goto err_devfreq_add;
+	}
+
+	dev_info(dev, "DMC initialized\n");
+
+	return 0;
+
+err_devfreq_add:
+	exynos5_counters_disable_edev(dmc);
+remove_clocks:
+	clk_disable_unprepare(dmc->mout_bpll);
+	clk_disable_unprepare(dmc->fout_bpll);
+
+	return ret;
+}
+
+/**
+ * exynos5_dmc_remove() - Remove function for the platform device
+ * @pdev:	platform device which is going to be removed
+ *
+ * The function relies on 'devm' framework function which automatically
+ * clean the device's resources. It just calls explicitly disable function for
+ * the performance counters.
+ */
+static int exynos5_dmc_remove(struct platform_device *pdev)
+{
+	struct exynos5_dmc *dmc = dev_get_drvdata(&pdev->dev);
+
+	exynos5_counters_disable_edev(dmc);
+
+	clk_disable_unprepare(dmc->mout_bpll);
+	clk_disable_unprepare(dmc->fout_bpll);
+
+	dev_pm_opp_remove_table(dmc->dev);
+
+	return 0;
+}
+
+static const struct of_device_id exynos5_dmc_of_match[] = {
+	{ .compatible = "samsung,exynos5422-dmc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, exynos5_dmc_of_match);
+
+static struct platform_driver exynos5_dmc_platdrv = {
+	.probe	= exynos5_dmc_probe,
+	.remove = exynos5_dmc_remove,
+	.driver = {
+		.name	= "exynos5-dmc",
+		.of_match_table = exynos5_dmc_of_match,
+	},
+};
+module_platform_driver(exynos5_dmc_platdrv);
+MODULE_DESCRIPTION("Driver for Exynos5422 Dynamic Memory Controller dynamic frequency and voltage change");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Lukasz Luba");
-- 
2.17.1

Re: [PATCH v13 5/8] drivers: memory: add DMC driver for Exynos5422

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:43:00PM +0200, Lukasz Luba wrote:
> This patch adds driver for Exynos5422 Dynamic Memory Controller.
> The driver provides support for dynamic frequency and voltage scaling
> for DMC and DRAM. It supports changing timings of DRAM running with
> different frequency. There is also an algorithm to calculate timigns
> based on memory description provided in DT.
> The patch also contains needed MAINTAINERS file update.
> 
> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
> ---
>  MAINTAINERS                             |    8 +
>  drivers/memory/samsung/Kconfig          |   13 +
>  drivers/memory/samsung/Makefile         |    1 +
>  drivers/memory/samsung/exynos5422-dmc.c | 1257 +++++++++++++++++++++++
>  4 files changed, 1279 insertions(+)
>  create mode 100644 drivers/memory/samsung/exynos5422-dmc.c

Thanks, applied... or almost. Let's fix it incrementally.

You have two smatch warnings:
  CHECK   ../drivers/memory/samsung/exynos5422-dmc.c
drivers/memory/samsung/exynos5422-dmc.c:272 exynos5_init_freq_table() warn: passing devm_ allocated variable to kfree. 'dmc->opp'
  CHECK   ../drivers/memory/jedec_ddr_data.c
drivers/memory/samsung/exynos5422-dmc.c:565 exynos5_dmc_get_volt_freq() warn: passing zero to 'PTR_ERR'

The second looks like false positive, but first seems to be real.

You have also sparse warning to fix:
../drivers/memory/samsung/exynos5422-dmc.c:736:1: warning: symbol 'exynos5_dmc_align_init_freq' was not declared. Should it be static?

Best regards,
Krzysztof

Re: [PATCH v13 5/8] drivers: memory: add DMC driver for Exynos5422

[Lukasz Luba]

On 9/4/19 8:35 PM, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2019 at 12:43:00PM +0200, Lukasz Luba wrote:
>> This patch adds driver for Exynos5422 Dynamic Memory Controller.
>> The driver provides support for dynamic frequency and voltage scaling
>> for DMC and DRAM. It supports changing timings of DRAM running with
>> different frequency. There is also an algorithm to calculate timigns
>> based on memory description provided in DT.
>> The patch also contains needed MAINTAINERS file update.
>>
>> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
>> ---
>>   MAINTAINERS                             |    8 +
>>   drivers/memory/samsung/Kconfig          |   13 +
>>   drivers/memory/samsung/Makefile         |    1 +
>>   drivers/memory/samsung/exynos5422-dmc.c | 1257 +++++++++++++++++++++++
>>   4 files changed, 1279 insertions(+)
>>   create mode 100644 drivers/memory/samsung/exynos5422-dmc.c
> 
> Thanks, applied... or almost. Let's fix it incrementally.
> 
> You have two smatch warnings:
>    CHECK   ../drivers/memory/samsung/exynos5422-dmc.c
> drivers/memory/samsung/exynos5422-dmc.c:272 exynos5_init_freq_table() warn: passing devm_ allocated variable to kfree. 'dmc->opp'
>    CHECK   ../drivers/memory/jedec_ddr_data.c
> drivers/memory/samsung/exynos5422-dmc.c:565 exynos5_dmc_get_volt_freq() warn: passing zero to 'PTR_ERR'
> 
> The second looks like false positive, but first seems to be real.
Right, I will fix it.
> 
> You have also sparse warning to fix:
> ../drivers/memory/samsung/exynos5422-dmc.c:736:1: warning: symbol 'exynos5_dmc_align_init_freq' was not declared. Should it be static?
Yes, it should be static but due to the artificial line break I have
missed it.

It will be sent in the follow up patch.

Thank you!

Regards,
Lukasz
> 
> Best regards,
> Krzysztof
> 
> 
> 

[PATCH v13 6/8] ARM: dts: exynos: add syscon to clock compatible

[Lukasz Luba]

In order to get the clock by phandle and use it with regmap it needs to be
compatible with syscon. The DMC driver uses two registers from clock
register set and needs the regmap of them.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 arch/arm/boot/dts/exynos5420.dtsi | 2 +-
 arch/arm/boot/dts/exynos5800.dtsi | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 55d4dbf6f83a..97dc10915680 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -175,7 +175,7 @@
 		};
 
 		clock: clock-controller@10010000 {
-			compatible = "samsung,exynos5420-clock";
+			compatible = "samsung,exynos5420-clock", "syscon";
 			reg = <0x10010000 0x30000>;
 			#clock-cells = <1>;
 		};
diff --git a/arch/arm/boot/dts/exynos5800.dtsi b/arch/arm/boot/dts/exynos5800.dtsi
index 57d3b319fd65..0a2b3287ed92 100644
--- a/arch/arm/boot/dts/exynos5800.dtsi
+++ b/arch/arm/boot/dts/exynos5800.dtsi
@@ -17,7 +17,7 @@
 };
 
 &clock {
-	compatible = "samsung,exynos5800-clock";
+	compatible = "samsung,exynos5800-clock", "syscon";
 };
 
 &cluster_a15_opp_table {
-- 
2.17.1

[PATCH v13 7/8] ARM: dts: exynos: add DMC device for exynos5422

[Lukasz Luba]

Add description of Dynamic Memory Controller and PPMU counters.
They are used by exynos5422-dmc driver.
There is a definition of the memory chip, which is then used during
calculation of timings for each OPP.
The algorithm in the driver needs these two sets to bound the timings.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 arch/arm/boot/dts/exynos5420.dtsi             |  71 +++++++++++
 arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 116 ++++++++++++++++++
 2 files changed, 187 insertions(+)

diff --git a/arch/arm/boot/dts/exynos5420.dtsi b/arch/arm/boot/dts/exynos5420.dtsi
index 97dc10915680..ac49373baae7 100644
--- a/arch/arm/boot/dts/exynos5420.dtsi
+++ b/arch/arm/boot/dts/exynos5420.dtsi
@@ -237,6 +237,29 @@
 			status = "disabled";
 		};
 
+		dmc: memory-controller@10c20000 {
+			compatible = "samsung,exynos5422-dmc";
+			reg = <0x10c20000 0x100>, <0x10c30000 0x100>;
+			clocks = <&clock CLK_FOUT_SPLL>,
+				 <&clock CLK_MOUT_SCLK_SPLL>,
+				 <&clock CLK_FF_DOUT_SPLL2>,
+				 <&clock CLK_FOUT_BPLL>,
+				 <&clock CLK_MOUT_BPLL>,
+				 <&clock CLK_SCLK_BPLL>,
+				 <&clock CLK_MOUT_MX_MSPLL_CCORE>,
+				 <&clock CLK_MOUT_MCLK_CDREX>;
+			clock-names = "fout_spll",
+				      "mout_sclk_spll",
+				      "ff_dout_spll2",
+				      "fout_bpll",
+				      "mout_bpll",
+				      "sclk_bpll",
+				      "mout_mx_mspll_ccore",
+				      "mout_mclk_cdrex";
+			samsung,syscon-clk = <&clock>;
+			status = "disabled";
+		};
+
 		nocp_mem0_0: nocp@10ca1000 {
 			compatible = "samsung,exynos5420-nocp";
 			reg = <0x10CA1000 0x200>;
@@ -273,6 +296,54 @@
 			status = "disabled";
 		};
 
+		ppmu_dmc0_0: ppmu@10d00000 {
+			compatible = "samsung,exynos-ppmu";
+			reg = <0x10d00000 0x2000>;
+			clocks = <&clock CLK_PCLK_PPMU_DREX0_0>;
+			clock-names = "ppmu";
+			events {
+				ppmu_event3_dmc0_0: ppmu-event3-dmc0_0 {
+					event-name = "ppmu-event3-dmc0_0";
+				};
+			};
+		};
+
+		ppmu_dmc0_1: ppmu@10d10000 {
+			compatible = "samsung,exynos-ppmu";
+			reg = <0x10d10000 0x2000>;
+			clocks = <&clock CLK_PCLK_PPMU_DREX0_1>;
+			clock-names = "ppmu";
+			events {
+				ppmu_event3_dmc0_1: ppmu-event3-dmc0_1 {
+					event-name = "ppmu-event3-dmc0_1";
+				};
+			};
+		};
+
+		ppmu_dmc1_0: ppmu@10d60000 {
+			compatible = "samsung,exynos-ppmu";
+			reg = <0x10d60000 0x2000>;
+			clocks = <&clock CLK_PCLK_PPMU_DREX1_0>;
+			clock-names = "ppmu";
+			events {
+				ppmu_event3_dmc1_0: ppmu-event3-dmc1_0 {
+					event-name = "ppmu-event3-dmc1_0";
+				};
+			};
+		};
+
+		ppmu_dmc1_1: ppmu@10d70000 {
+			compatible = "samsung,exynos-ppmu";
+			reg = <0x10d70000 0x2000>;
+			clocks = <&clock CLK_PCLK_PPMU_DREX1_1>;
+			clock-names = "ppmu";
+			events {
+				ppmu_event3_dmc1_1: ppmu-event3-dmc1_1 {
+					event-name = "ppmu-event3-dmc1_1";
+				};
+			};
+		};
+
 		gsc_pd: power-domain@10044000 {
 			compatible = "samsung,exynos4210-pd";
 			reg = <0x10044000 0x20>;
diff --git a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
index 829147e320e0..fe885ca969af 100644
--- a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
+++ b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
@@ -34,6 +34,97 @@
 			clock-frequency = <24000000>;
 		};
 	};
+
+	dmc_opp_table: opp_table2 {
+		compatible = "operating-points-v2";
+
+		opp00 {
+			opp-hz = /bits/ 64 <165000000>;
+			opp-microvolt = <875000>;
+		};
+		opp01 {
+			opp-hz = /bits/ 64 <206000000>;
+			opp-microvolt = <875000>;
+		};
+		opp02 {
+			opp-hz = /bits/ 64 <275000000>;
+			opp-microvolt = <875000>;
+		};
+		opp03 {
+			opp-hz = /bits/ 64 <413000000>;
+			opp-microvolt = <887500>;
+		};
+		opp04 {
+			opp-hz = /bits/ 64 <543000000>;
+			opp-microvolt = <937500>;
+		};
+		opp05 {
+			opp-hz = /bits/ 64 <633000000>;
+			opp-microvolt = <1012500>;
+		};
+		opp06 {
+			opp-hz = /bits/ 64 <728000000>;
+			opp-microvolt = <1037500>;
+		};
+		opp07 {
+			opp-hz = /bits/ 64 <825000000>;
+			opp-microvolt = <1050000>;
+		};
+	};
+
+	samsung_K3QF2F20DB: lpddr3 {
+		compatible	= "samsung,K3QF2F20DB", "jedec,lpddr3";
+		density		= <16384>;
+		io-width	= <32>;
+		#address-cells  = <1>;
+		#size-cells     = <0>;
+
+		tRFC-min-tck		= <17>;
+		tRRD-min-tck		= <2>;
+		tRPab-min-tck		= <2>;
+		tRPpb-min-tck		= <2>;
+		tRCD-min-tck		= <3>;
+		tRC-min-tck		= <6>;
+		tRAS-min-tck		= <5>;
+		tWTR-min-tck		= <2>;
+		tWR-min-tck		= <7>;
+		tRTP-min-tck		= <2>;
+		tW2W-C2C-min-tck	= <0>;
+		tR2R-C2C-min-tck	= <0>;
+		tWL-min-tck		= <8>;
+		tDQSCK-min-tck		= <5>;
+		tRL-min-tck		= <14>;
+		tFAW-min-tck		= <5>;
+		tXSR-min-tck		= <12>;
+		tXP-min-tck		= <2>;
+		tCKE-min-tck		= <2>;
+		tCKESR-min-tck		= <2>;
+		tMRD-min-tck		= <5>;
+
+		timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
+			compatible	= "jedec,lpddr3-timings";
+			reg		= <800000000>; /* workaround: it shows max-freq */
+			min-freq	= <100000000>;
+			tRFC		= <65000>;
+			tRRD		= <6000>;
+			tRPab		= <12000>;
+			tRPpb		= <12000>;
+			tRCD		= <10000>;
+			tRC		= <33750>;
+			tRAS		= <23000>;
+			tWTR		= <3750>;
+			tWR		= <7500>;
+			tRTP		= <3750>;
+			tW2W-C2C	= <0>;
+			tR2R-C2C	= <0>;
+			tFAW		= <25000>;
+			tXSR		= <70000>;
+			tXP		= <3750>;
+			tCKE		= <3750>;
+			tCKESR		= <3750>;
+			tMRD		= <7000>;
+		};
+	};
 };
 
 &adc {
@@ -132,6 +223,15 @@
 	cpu-supply = <&buck2_reg>;
 };
 
+&dmc {
+	devfreq-events = <&ppmu_event3_dmc0_0>,	<&ppmu_event3_dmc0_1>,
+			<&ppmu_event3_dmc1_0>, <&ppmu_event3_dmc1_1>;
+	device-handle = <&samsung_K3QF2F20DB>;
+	operating-points-v2 = <&dmc_opp_table>;
+	vdd-supply = <&buck1_reg>;
+	status = "okay";
+};
+
 &hsi2c_4 {
 	status = "okay";
 
@@ -634,6 +734,22 @@
 	};
 };
 
+&ppmu_dmc0_0 {
+	status = "okay";
+};
+
+&ppmu_dmc0_1 {
+	status = "okay";
+};
+
+&ppmu_dmc1_0 {
+	status = "okay";
+};
+
+&ppmu_dmc1_1 {
+	status = "okay";
+};
+
 &tmu_cpu0 {
 	vtmu-supply = <&ldo7_reg>;
 };
-- 
2.17.1

Re: [PATCH v13 7/8] ARM: dts: exynos: add DMC device for exynos5422

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:43:02PM +0200, Lukasz Luba wrote:
> Add description of Dynamic Memory Controller and PPMU counters.
> They are used by exynos5422-dmc driver.
> There is a definition of the memory chip, which is then used during
> calculation of timings for each OPP.
> The algorithm in the driver needs these two sets to bound the timings.
> 
> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
> ---
>  arch/arm/boot/dts/exynos5420.dtsi             |  71 +++++++++++
>  arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 116 ++++++++++++++++++
>  2 files changed, 187 insertions(+)

Thanks, applied conditionally. Please send a follow up fixing the
checkpatch error about undocumented binding:
https://krzk.eu/#/builders/26/builds/392

You should not skip such checkpatch warning.

Best regards,
Krzysztof

Re: [PATCH v13 7/8] ARM: dts: exynos: add DMC device for exynos5422

[Lukasz Luba]

Hi Krzysztof,

On 9/4/19 8:25 PM, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2019 at 12:43:02PM +0200, Lukasz Luba wrote:
>> Add description of Dynamic Memory Controller and PPMU counters.
>> They are used by exynos5422-dmc driver.
>> There is a definition of the memory chip, which is then used during
>> calculation of timings for each OPP.
>> The algorithm in the driver needs these two sets to bound the timings.
>>
>> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
>> ---
>>   arch/arm/boot/dts/exynos5420.dtsi             |  71 +++++++++++
>>   arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 116 ++++++++++++++++++
>>   2 files changed, 187 insertions(+)
> 
> Thanks, applied conditionally. Please send a follow up fixing the
> checkpatch error about undocumented binding:
> https://krzk.eu/#/builders/26/builds/392
> 
> You should not skip such checkpatch warning.
Right, I will keep it in mind next time. I have just ignore it based on
Elpida lpddr2 memory which is also missing DT binding documentation.
https://elixir.bootlin.com/linux/v5.3-rc7/source/arch/arm/boot/dts/elpida_ecb240abacn.dtsi

I will send a follow up patch based on your 'for-next' branch.

Regards,
Lukasz
> 
> Best regards,
> Krzysztof
> 
> 
> 

[PATCH v13 8/8] ARM: exynos_defconfig: enable DMC driver

[Lukasz Luba]

Enable driver for Exynos5422 Dynamic Memory Controller supporting
dynamic frequency and voltage scaling in Exynos5422 SoCs.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
 arch/arm/configs/exynos_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/configs/exynos_defconfig b/arch/arm/configs/exynos_defconfig
index 2e6a863d25aa..ebed93236a47 100644
--- a/arch/arm/configs/exynos_defconfig
+++ b/arch/arm/configs/exynos_defconfig
@@ -291,6 +291,7 @@ CONFIG_DEVFREQ_GOV_PERFORMANCE=y
 CONFIG_DEVFREQ_GOV_POWERSAVE=y
 CONFIG_DEVFREQ_GOV_USERSPACE=y
 CONFIG_ARM_EXYNOS_BUS_DEVFREQ=y
+CONFIG_EXYNOS5422_DMC=y
 CONFIG_DEVFREQ_EVENT_EXYNOS_NOCP=y
 CONFIG_EXTCON=y
 CONFIG_EXTCON_MAX14577=y
-- 
2.17.1

Re: [PATCH v13 8/8] ARM: exynos_defconfig: enable DMC driver

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:43:03PM +0200, Lukasz Luba wrote:
> Enable driver for Exynos5422 Dynamic Memory Controller supporting
> dynamic frequency and voltage scaling in Exynos5422 SoCs.
> 
> Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
> ---
>  arch/arm/configs/exynos_defconfig | 1 +

Thanks, applied.

Best regards,
Krzysztof

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Krzysztof Kozlowski]

On Wed, 21 Aug 2019 at 12:43, Lukasz Luba <l.luba@partner.samsung.com> wrote:
>
> Hi all,
>
> This is v13 which makes cosmetic changes. It is based on current mainline
> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
>
> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
> The driver supports Dynamic Voltage and Frequency Scaling
> for the DMC and DRAM. It also provides needed timings for different
> speed operations of the DRAM memory.
> There is also new generic code in of_memory and headers which allows to parse
> LPDDR3 memories defined in device-tree.
>
> Here are the last changes suggested by Krzysztof during his review.
> For the previous changes in older revisions please refer to [2], there is
> more detailed change log.
>
> changes:
> v13:
> - skipped patch with chipID changes in DT, since it is not used anymore,
> - removed license comment in of_memory.c since SPDX has been merged,
> - aligned comment to the current fields in the structure,
> - changed printed warning when timings are not found,
>
> Regards,
> Lukasz Luba
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
> [2] https://lkml.org/lkml/2019/7/22/251
>

Hi Lukasz,

Thanks for the effort and work on this patchset. The text-based
bindings are slowly converted to JSON-schema but your patches were
developed some time ago and have Rob's review. It would be nice if you
or someone converted it to JSON schema later.
Anyway, I'll pick up everything today evening either for this merge
window or eventually postponed till next one. It is quite late in the
cycle and I want the patches to sit in linux-next for some time.

Best regards,
Krzysztof

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Lukasz Luba]

Hi Krzysztof,

On 9/4/19 12:16 PM, Krzysztof Kozlowski wrote:
> On Wed, 21 Aug 2019 at 12:43, Lukasz Luba <l.luba@partner.samsung.com> wrote:
>>
>> Hi all,
>>
>> This is v13 which makes cosmetic changes. It is based on current mainline
>> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
>>
>> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
>> The driver supports Dynamic Voltage and Frequency Scaling
>> for the DMC and DRAM. It also provides needed timings for different
>> speed operations of the DRAM memory.
>> There is also new generic code in of_memory and headers which allows to parse
>> LPDDR3 memories defined in device-tree.
>>
>> Here are the last changes suggested by Krzysztof during his review.
>> For the previous changes in older revisions please refer to [2], there is
>> more detailed change log.
>>
>> changes:
>> v13:
>> - skipped patch with chipID changes in DT, since it is not used anymore,
>> - removed license comment in of_memory.c since SPDX has been merged,
>> - aligned comment to the current fields in the structure,
>> - changed printed warning when timings are not found,
>>
>> Regards,
>> Lukasz Luba
>>
>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
>> [2] https://lkml.org/lkml/2019/7/22/251
>>
> 
> Hi Lukasz,
> 
> Thanks for the effort and work on this patchset. The text-based
> bindings are slowly converted to JSON-schema but your patches were
> developed some time ago and have Rob's review. It would be nice if you
> or someone converted it to JSON schema later.
> Anyway, I'll pick up everything today evening either for this merge
> window or eventually postponed till next one. It is quite late in the
> cycle and I want the patches to sit in linux-next for some time.
Thank you for taking the patches.
OK, I will convert the bindings to JSON format later, when the patches
land into mainline.

Regards,
Lukasz Luba
> 
> Best regards,
> Krzysztof
> 
> 

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:42:55PM +0200, Lukasz Luba wrote:
> Hi all,
> 
> This is v13 which makes cosmetic changes. It is based on current mainline
> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
> 
> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
> The driver supports Dynamic Voltage and Frequency Scaling
> for the DMC and DRAM. It also provides needed timings for different
> speed operations of the DRAM memory.
> There is also new generic code in of_memory and headers which allows to parse
> LPDDR3 memories defined in device-tree.
> 
> Here are the last changes suggested by Krzysztof during his review.
> For the previous changes in older revisions please refer to [2], there is
> more detailed change log.
> 
> changes:
> v13:
> - skipped patch with chipID changes in DT, since it is not used anymore,
> - removed license comment in of_memory.c since SPDX has been merged,
> - aligned comment to the current fields in the structure,
> - changed printed warning when timings are not found,
> 
> Regards,
> Lukasz Luba
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
> [2] https://lkml.org/lkml/2019/7/22/251
> 

Thanks, applied entire set (except last defconfig patch) to two topic
branches, either for v5.4 or for v5.5 (it is quite late). I'll take the
last defconfig separately.

Automated tools found few issues to fix, please send incremental
patches.

In general, for new drivers always run automated checks - Smatch and
Sparse. Coccinelle is also recommended. Checkpatch pointed missing
compatible documentation - need to be fixed (see
https://elixir.bootlin.com/linux/v5.3-rc7/source/Documentation/devicetree/bindings/eeprom/at25.txt
as an example).

Best regards,
Krzysztof

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Lukasz Luba]

On 9/4/19 8:40 PM, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2019 at 12:42:55PM +0200, Lukasz Luba wrote:
>> Hi all,
>>
>> This is v13 which makes cosmetic changes. It is based on current mainline
>> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
>>
>> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
>> The driver supports Dynamic Voltage and Frequency Scaling
>> for the DMC and DRAM. It also provides needed timings for different
>> speed operations of the DRAM memory.
>> There is also new generic code in of_memory and headers which allows to parse
>> LPDDR3 memories defined in device-tree.
>>
>> Here are the last changes suggested by Krzysztof during his review.
>> For the previous changes in older revisions please refer to [2], there is
>> more detailed change log.
>>
>> changes:
>> v13:
>> - skipped patch with chipID changes in DT, since it is not used anymore,
>> - removed license comment in of_memory.c since SPDX has been merged,
>> - aligned comment to the current fields in the structure,
>> - changed printed warning when timings are not found,
>>
>> Regards,
>> Lukasz Luba
>>
>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
>> [2] https://lkml.org/lkml/2019/7/22/251
>>
> 
> Thanks, applied entire set (except last defconfig patch) to two topic
> branches, either for v5.4 or for v5.5 (it is quite late). I'll take the
> last defconfig separately.
> 
> Automated tools found few issues to fix, please send incremental
> patches.
OK, there will be around 3 patches with fixes.
> 
> In general, for new drivers always run automated checks - Smatch and
> Sparse. Coccinelle is also recommended. Checkpatch pointed missing
> compatible documentation - need to be fixed (see
> https://elixir.bootlin.com/linux/v5.3-rc7/source/Documentation/devicetree/bindings/eeprom/at25.txt
> as an example).
As I have responded in my previous email, I ignored it since Elpida
lpddr2 does not have bindings documentation. I will create the needed
documentation file in the follow up patch.

Regards,
Lukasz

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Krzysztof Kozlowski]

On Wed, Aug 21, 2019 at 12:42:55PM +0200, Lukasz Luba wrote:
> Hi all,
> 
> This is v13 which makes cosmetic changes. It is based on current mainline
> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
> 
> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
> The driver supports Dynamic Voltage and Frequency Scaling
> for the DMC and DRAM. It also provides needed timings for different
> speed operations of the DRAM memory.
> There is also new generic code in of_memory and headers which allows to parse
> LPDDR3 memories defined in device-tree.
> 
> Here are the last changes suggested by Krzysztof during his review.
> For the previous changes in older revisions please refer to [2], there is
> more detailed change log.
> 
> changes:
> v13:
> - skipped patch with chipID changes in DT, since it is not used anymore,
> - removed license comment in of_memory.c since SPDX has been merged,
> - aligned comment to the current fields in the structure,
> - changed printed warning when timings are not found,
> 
> Regards,
> Lukasz Luba
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
> [2] https://lkml.org/lkml/2019/7/22/251
> 
> 
> Lukasz Luba (8):
>   dt-bindings: ddr: rename lpddr2 directory
>   dt-bindings: ddr: add LPDDR3 memories
>   drivers: memory: extend of_memory by LPDDR3 support
>   dt-bindings: memory-controllers: add Exynos5422 DMC device description
>   drivers: memory: add DMC driver for Exynos5422
>   ARM: dts: exynos: add syscon to clock compatible
>   ARM: dts: exynos: add DMC device for exynos5422
>   ARM: exynos_defconfig: enable DMC driver
>

Just to let you know:

I applied the set some days ago but this did not make to merge window.
Now, I put it on for-next branch so will appear on linux-next soon. I
also applied the fixes sent later.

I'll take also the latest work with interrupt mode for DMC (after minor
fix in bindings).

Best regards,
Krzysztof

Re: [PATCH v13 0/8] Exynos5 Dynamic Memory Controller driver

[Lukasz Luba]

On 10/1/19 9:29 PM, Krzysztof Kozlowski wrote:
> On Wed, Aug 21, 2019 at 12:42:55PM +0200, Lukasz Luba wrote:
>> Hi all,
>>
>> This is v13 which makes cosmetic changes. It is based on current mainline
>> (v5.3-rc5) with with devfreq/for-next where there is a PPMU patch [1].
>>
>> The patch set adds support of Dynamic Memory Controller for Exynos5422 SoC.
>> The driver supports Dynamic Voltage and Frequency Scaling
>> for the DMC and DRAM. It also provides needed timings for different
>> speed operations of the DRAM memory.
>> There is also new generic code in of_memory and headers which allows to parse
>> LPDDR3 memories defined in device-tree.
>>
>> Here are the last changes suggested by Krzysztof during his review.
>> For the previous changes in older revisions please refer to [2], there is
>> more detailed change log.
>>
>> changes:
>> v13:
>> - skipped patch with chipID changes in DT, since it is not used anymore,
>> - removed license comment in of_memory.c since SPDX has been merged,
>> - aligned comment to the current fields in the structure,
>> - changed printed warning when timings are not found,
>>
>> Regards,
>> Lukasz Luba
>>
>> [1] https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git/commit/?h=for-next&id=b617376df8f01c975dee66802f4da16291f92079
>> [2] https://protect2.fireeye.com/url?k=76a66a31f783ea89.76a7e17e-142fcaf2360aff73&u=https://lkml.org/lkml/2019/7/22/251
>>
>>
>> Lukasz Luba (8):
>>    dt-bindings: ddr: rename lpddr2 directory
>>    dt-bindings: ddr: add LPDDR3 memories
>>    drivers: memory: extend of_memory by LPDDR3 support
>>    dt-bindings: memory-controllers: add Exynos5422 DMC device description
>>    drivers: memory: add DMC driver for Exynos5422
>>    ARM: dts: exynos: add syscon to clock compatible
>>    ARM: dts: exynos: add DMC device for exynos5422
>>    ARM: exynos_defconfig: enable DMC driver
>>
> 
> Just to let you know:
> 
> I applied the set some days ago but this did not make to merge window.
> Now, I put it on for-next branch so will appear on linux-next soon. I
> also applied the fixes sent later.

Thank you Krzysztof!

> 
> I'll take also the latest work with interrupt mode for DMC (after minor
> fix in bindings).
> 

I will send the latest IRQ mode version with this binding IRQ names
description in a minute.

Regards,
Lukasz