[PATCH v2, 0/3] 8183 emi driver support

[PATCH v2, 0/3] 8183 emi driver support

[Xi Chen]

Remove global emi_dev.

Xi Chen (3):
  dt-bindings: soc: Add MT8183 emi dt-bindings
  arm64: dts: mt8183: add emi node
  mt8183: emi: add bandwidth driver support

 .../bindings/memory-controllers/mediatek,emi.txt   |  19 ++
 arch/arm64/boot/dts/mediatek/mt8183.dtsi           |  11 +
 drivers/memory/Kconfig                             |   9 +
 drivers/memory/Makefile                            |   1 +
 drivers/memory/mtk-emi.c                           | 379 +++++++++++++++++++++
 include/soc/mediatek/emi.h                         | 116 +++++++
 6 files changed, 535 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
 create mode 100644 drivers/memory/mtk-emi.c
 create mode 100644 include/soc/mediatek/emi.h

-- 
1.9.1

[PATCH v2, 1/3] dt-bindings: soc: Add MT8183 emi dt-bindings

[Xi Chen]

Add emi dt-bindings of MT8183 in binding document.

Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 .../bindings/memory-controllers/mediatek,emi.txt      | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
new file mode 100644
index 0000000..a19e3b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
@@ -0,0 +1,19 @@
+EMI (External Memory Interface)
+
+Required properties:
+- compatible : must be one of :
+	"mediatek,mt8183-emi"
+- reg : the register and size of the EMI block.
+- interrupts : includes MPU, CGM, ELM.
+
+Example:
+	emi@10219000 {
+	compatible = "mediatek,mt8183-emi";
+	reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
+		  <0 0x10226000 0 0x1000>, /* EMI MPU */
+		  <0 0x1022d000 0 0x1000>, /* CHA EMI */
+		  <0 0x10235000 0 0x1000>; /* CHB EMI */
+	interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
+			 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
+			 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
+};
-- 
1.9.1

Re: [PATCH v2, 1/3] dt-bindings: soc: Add MT8183 emi dt-bindings

[Matthias Brugger]

On 24/05/2019 05:54, Xi Chen wrote:
> Add emi dt-bindings of MT8183 in binding document.
> 
> Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>  .../bindings/memory-controllers/mediatek,emi.txt      | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> 
> diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> new file mode 100644
> index 0000000..a19e3b3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> @@ -0,0 +1,19 @@
> +EMI (External Memory Interface)
> +

Please describe a bit more what the EMI interface does.

> +Required properties:
> +- compatible : must be one of :
> +	"mediatek,mt8183-emi"
> +- reg : the register and size of the EMI block.
> +- interrupts : includes MPU, CGM, ELM.
> +
> +Example:
> +	emi@10219000 {
> +	compatible = "mediatek,mt8183-emi";
> +	reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
> +		  <0 0x10226000 0 0x1000>, /* EMI MPU */
> +		  <0 0x1022d000 0 0x1000>, /* CHA EMI */
> +		  <0 0x10235000 0 0x1000>; /* CHB EMI */
> +	interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
> +			 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
> +			 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
> +};
> 

Re: [PATCH v2, 1/3] dt-bindings: soc: Add MT8183 emi dt-bindings

[Matthias Brugger]

On 24/05/2019 05:54, Xi Chen wrote:
> Add emi dt-bindings of MT8183 in binding document.
> 
> Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>  .../bindings/memory-controllers/mediatek,emi.txt      | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> 
> diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> new file mode 100644
> index 0000000..a19e3b3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> @@ -0,0 +1,19 @@
> +EMI (External Memory Interface)
> +
> +Required properties:
> +- compatible : must be one of :
> +	"mediatek,mt8183-emi"
> +- reg : the register and size of the EMI block.

Please name the registers explicitly.

> +- interrupts : includes MPU, CGM, ELM.
> +
> +Example:
> +	emi@10219000 {
> +	compatible = "mediatek,mt8183-emi";

Please do the indention right.

> +	reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
> +		  <0 0x10226000 0 0x1000>, /* EMI MPU */
> +		  <0 0x1022d000 0 0x1000>, /* CHA EMI */
> +		  <0 0x10235000 0 0x1000>; /* CHB EMI */

This looks quite spread out over the IO space. Is this really one HW block or
did you add various blocks into one driver?

> +	interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
> +			 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
> +			 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
> +};
> 

Re: [PATCH v2, 1/3] dt-bindings: soc: Add MT8183 emi dt-bindings

[Xi Chen]

On Tue, 2019-06-18 at 23:32 +0200, Matthias Brugger wrote:
> 
> On 24/05/2019 05:54, Xi Chen wrote:
> > Add emi dt-bindings of MT8183 in binding document.
> > 
> > Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> > ---
> >  .../bindings/memory-controllers/mediatek,emi.txt      | 19 +++++++++++++++++++
> >  1 file changed, 19 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> > new file mode 100644
> > index 0000000..a19e3b3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/memory-controllers/mediatek,emi.txt
> > @@ -0,0 +1,19 @@
> > +EMI (External Memory Interface)
> > +
> > +Required properties:
> > +- compatible : must be one of :
> > +	"mediatek,mt8183-emi"
> > +- reg : the register and size of the EMI block.
> 
> Please name the registers explicitly.
	the "reg" is emi reg base.
> 
> > +- interrupts : includes MPU, CGM, ELM.
> > +
> > +Example:
> > +	emi@10219000 {
> > +	compatible = "mediatek,mt8183-emi";
> 
> Please do the indention right.
	Yes, I do the indention right.
> 
> > +	reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
> > +		  <0 0x10226000 0 0x1000>, /* EMI MPU */
> > +		  <0 0x1022d000 0 0x1000>, /* CHA EMI */
> > +		  <0 0x10235000 0 0x1000>; /* CHB EMI */
> 
> This looks quite spread out over the IO space. Is this really one HW block or
> did you add various blocks into one driver?
	Yes, you are right. I removed the unused reg addr and interrupts.
> 
> > +	interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
> > +			 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
> > +			 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
> > +};
> > 

[PATCH v2, 2/3] arm64: dts: mt8183: add emi node

[Xi Chen]

Add emi dts node.

Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 arch/arm64/boot/dts/mediatek/mt8183.dtsi | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
index 75c4881..2a176e9 100644
--- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
@@ -269,6 +269,17 @@
 			clock-names = "spi", "wrap";
 		};
 
+		emi@10219000 {
+			compatible = "mediatek,mt8183-emi";
+			reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
+				  <0 0x10226000 0 0x1000>, /* EMI MPU */
+				  <0 0x1022d000 0 0x1000>, /* CHA EMI */
+			      <0 0x10235000 0 0x1000>; /* CHB EMI */
+			interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
+						 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
+						 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
+		};
+
 		uart0: serial@11002000 {
 			compatible = "mediatek,mt8183-uart",
 				     "mediatek,mt6577-uart";
-- 
1.9.1

Re: [PATCH v2, 2/3] arm64: dts: mt8183: add emi node

[Matthias Brugger]

On 24/05/2019 05:54, Xi Chen wrote:
> Add emi dts node.
> 
> Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>  arch/arm64/boot/dts/mediatek/mt8183.dtsi | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> index 75c4881..2a176e9 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> @@ -269,6 +269,17 @@
>  			clock-names = "spi", "wrap";
>  		};
>  
> +		emi@10219000 {
> +			compatible = "mediatek,mt8183-emi";
> +			reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
> +				  <0 0x10226000 0 0x1000>, /* EMI MPU */
> +				  <0 0x1022d000 0 0x1000>, /* CHA EMI */
> +			      <0 0x10235000 0 0x1000>; /* CHB EMI */
> +			interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
> +						 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
> +						 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */

indentation seems borken here.

> +		};
> +
>  		uart0: serial@11002000 {
>  			compatible = "mediatek,mt8183-uart",
>  				     "mediatek,mt6577-uart";
> 

Re: [PATCH v2, 2/3] arm64: dts: mt8183: add emi node

[Xi Chen]

On Tue, 2019-06-18 at 23:32 +0200, Matthias Brugger wrote:
> 
> On 24/05/2019 05:54, Xi Chen wrote:
> > Add emi dts node.
> > 
> > Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> > ---
> >  arch/arm64/boot/dts/mediatek/mt8183.dtsi | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/mediatek/mt8183.dtsi b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > index 75c4881..2a176e9 100644
> > --- a/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > +++ b/arch/arm64/boot/dts/mediatek/mt8183.dtsi
> > @@ -269,6 +269,17 @@
> >  			clock-names = "spi", "wrap";
> >  		};
> >  
> > +		emi@10219000 {
> > +			compatible = "mediatek,mt8183-emi";
> > +			reg = <0 0x10219000 0 0x1000>, /* CEN EMI */
> > +				  <0 0x10226000 0 0x1000>, /* EMI MPU */
> > +				  <0 0x1022d000 0 0x1000>, /* CHA EMI */
> > +			      <0 0x10235000 0 0x1000>; /* CHB EMI */
> > +			interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_LOW>, /* MPU */
> > +						 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>, /* CGM */
> > +						 <GIC_SPI 155 IRQ_TYPE_LEVEL_HIGH>; /* ELM */
> 
> indentation seems borken here.
	sorry, broken some blanks.
> 
> > +		};
> > +
> >  		uart0: serial@11002000 {
> >  			compatible = "mediatek,mt8183-uart",
> >  				     "mediatek,mt6577-uart";
> > 
> 
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

[PATCH v2, 3/3] mt8183: emi: add bandwidth driver support

[Xi Chen]

EMI provides interface for get bandwidth  on every 1 miliseconds.
Currently, just support GPU bandwidth info.

Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 drivers/memory/Kconfig     |   9 ++
 drivers/memory/Makefile    |   1 +
 drivers/memory/mtk-emi.c   | 373 +++++++++++++++++++++++++++++++++++++++++++++
 include/soc/mediatek/emi.h | 116 ++++++++++++++
 4 files changed, 499 insertions(+)
 create mode 100644 drivers/memory/mtk-emi.c
 create mode 100644 include/soc/mediatek/emi.h

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 2d91b00..2a76bfe 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -129,6 +129,15 @@ config JZ4780_NEMC
 	  the Ingenic JZ4780. This controller is used to handle external
 	  memory devices such as NAND and SRAM.
 
+config MTK_EMI_MBW
+	bool "Mediatek EMI bandwidth driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+	  This driver is for MTK EMI control.
+	  If unsure, use N.
+	  This is the first time emi upstream.
+	  Only support emi bw statistics.
+
 config MTK_SMI
 	bool
 	depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 90161de..4f8b241 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_FSL_CORENET_CF)	+= fsl-corenet-cf.o
 obj-$(CONFIG_FSL_IFC)		+= fsl_ifc.o
 obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
 obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
+obj-$(CONFIG_MTK_EMI_MBW)	+= mtk-emi.o
 obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
 obj-$(CONFIG_DA8XX_DDRCTL)	+= da8xx-ddrctl.o
 obj-$(CONFIG_PL353_SMC)		+= pl353-smc.o
diff --git a/drivers/memory/mtk-emi.c b/drivers/memory/mtk-emi.c
new file mode 100644
index 0000000..acbe5a6
--- /dev/null
+++ b/drivers/memory/mtk-emi.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 MediaTek Inc.
+ * Author: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
+ */
+
+#include <linux/cdev.h>
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+#include <soc/mediatek/emi.h>
+
+/* 67ms emi bw  */
+#define EMI_BW_ARRAY_SIZE	67
+
+struct mtk_emi {
+	struct device *dev;
+	void __iomem *cen_emi_base;
+	void __iomem *chn_emi_base[MAX_CH];
+	void __iomem *emi_mpu_base;
+
+	struct timer_list emi_bw_timer;
+	struct timeval old_tv;
+
+	unsigned long long emi_bw_array[EMI_BW_ARRAY_SIZE];
+	int emi_bw_cur_idx;
+};
+
+static unsigned long long emi_get_max_bw_in_last_array(struct device *dev,
+	unsigned long long arr[], unsigned int size)
+{
+	unsigned int i = 0;
+	unsigned long long max = arr[0];
+
+	while (i < size) {
+		if (arr[i] > max)
+			max = arr[i];
+		++i;
+	}
+	return max;
+}
+
+unsigned long long mtk_emi_get_max_bw(struct device *dev)
+{
+	struct mtk_emi *emi;
+
+	if (!dev)
+		return 0;
+
+	emi = dev_get_drvdata(dev);
+	return emi_get_max_bw_in_last_array(dev,
+		emi->emi_bw_array, ARRAY_SIZE(emi->emi_bw_array));
+}
+EXPORT_SYMBOL(mtk_emi_get_max_bw);
+
+static void emi_update_bw_array(struct device *dev, unsigned int val)
+{
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	if (emi->emi_bw_cur_idx == emi->EMI_BW_ARRAY_SIZE) {
+		/* remove the first array element */
+		memmove(emi->emi_bw_array, emi->emi_bw_array + 1,
+			sizeof(unsigned long long) * (emi->EMI_BW_ARRAY_SIZE - 1));
+		emi->emi_bw_array[emi->EMI_BW_ARRAY_SIZE - 1] = val;
+	} else
+		emi->emi_bw_array[emi->emi_bw_cur_idx++] = val;
+}
+
+static void emi_dump_bw_array(struct device *dev)
+{
+	int i = 0;
+	const int unit = 10;
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	while (i < emi->EMI_BW_ARRAY_SIZE) {
+		if (i != 0 && i % unit == 0)
+			pr_info("\n");
+		pr_info("0x%x ", emi->emi_bw_array[i]);
+
+		++i;
+	}
+
+	pr_info("\n");
+}
+
+static void emi_counter_reset(struct device *dev)
+{
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	writel(EMI_BMEN_DEFAULT_VALUE, EMI_BMEN);
+	writel(EMI_MSEL_DEFAULT_VALUE, EMI_MSEL);
+	writel(EMI_MSEL2_DEFAULT_VALUE, EMI_MSEL2);
+	writel(EMI_BMEN2_DEFAULT_VALUE, EMI_BMEN2);
+	writel(EMI_BMRW0_DEFAULT_VALUE, EMI_BMRW0);
+}
+
+static void emi_counter_pause(struct device *dev)
+{
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+	const unsigned int value = readl(EMI_BMEN);
+
+	/* BW monitor */
+	writel(value | BUS_MON_PAUSE, EMI_BMEN);
+}
+
+static void emi_counter_continue(struct device *dev)
+{
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+	const unsigned int value = readl(EMI_BMEN);
+
+	/* BW monitor */
+	writel(value & (~BUS_MON_PAUSE), EMI_BMEN);
+}
+
+static void emi_counter_enable(struct device *dev, const unsigned int enable)
+{
+	unsigned int value, value_set;
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	value = readl(EMI_BMEN);
+	if (!enable) {	/* disable monitor circuit */
+		/*  bit3 =1	bit0 = 0-> clear */
+		value_set = (value) | (BUS_MON_IDLE);
+		writel(value_set, EMI_BMEN);
+
+		value_set = ((value) | (BUS_MON_IDLE)) & ~(BUS_MON_EN);
+		writel(value_set, EMI_BMEN);
+
+		value_set = ((value) & ~(BUS_MON_IDLE)) & ~(BUS_MON_EN);
+		writel(value_set, EMI_BMEN);
+	} else {		/* enable monitor circuit */
+		/*  bit3 =0	&   bit0=1 */
+		value_set = (value & ~(BUS_MON_IDLE));
+		writel(value_set, EMI_BMEN);
+
+		value_set = (value & ~(BUS_MON_IDLE)) | (BUS_MON_EN);
+		writel(value_set, EMI_BMEN);
+	}
+}
+
+/*****************************************************************************
+ *  APIs
+ *****************************************************************************/
+static void mtk_emi_mon_start(struct device *dev)
+{
+	emi_counter_enable(dev, 0);
+	emi_counter_reset(dev);
+	emi_counter_enable(dev, 1);
+}
+
+static void mtk_emi_mon_restart(struct device *dev)
+{
+	emi_counter_continue(dev);
+	emi_counter_enable(dev, 0);
+	emi_counter_reset(dev);
+	emi_counter_enable(dev, 1);
+}
+
+static void mtk_emi_mon_stop(struct device *dev)
+{
+	emi_counter_pause(dev);
+}
+
+static ssize_t emi_show_max_bw(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	unsigned long long var, bw_cpu;
+	unsigned int bw_gpu;
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	if (!dev) {
+		pr_warn("dev is null!!\n");
+		return 0;
+	}
+
+	var = mtk_emi_get_max_bw();
+	bw_gpu = readl(EMI_BWVL_4TH) & 0x7f;
+	bw_cpu = readl(EMI_WSCT3);
+
+	return scnprintf(buf, PAGE_SIZE,
+		"gpu_max_bw:%llu(0x%x) EMI_BWVL_4TH:0x%x, cpu:%llu(0x%x)\n",
+		var, var, bw_gpu, bw_cpu, bw_cpu);
+}
+
+DEVICE_ATTR(bw,  0440, emi_show_max_bw, NULL);
+
+static ssize_t emi_dump_bw(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	unsigned long long var;
+
+	if (!dev) {
+		pr_warn("dev is null!!\n");
+		return 0;
+	}
+
+	emi_dump_bw_array(dev);
+	var = mtk_emi_get_max_bw();
+
+	return scnprintf(buf, PAGE_SIZE,
+		"\temi_max_bw:%llu(0x%x)\n", var, var);
+}
+
+DEVICE_ATTR(dump_bw,  0440, emi_dump_bw, NULL);
+
+static int emi_bw_ms = 1;
+module_param_named(bw_ms, emi_bw_ms, int, 0664);
+
+static void emi_bw_timer_callback(struct timer_list *tm)
+{
+	struct timeval tv;
+	unsigned long long val, cur_max;
+	struct mtk_emi *emi = from_timer(mtk_emi, tm, emi_bw_timer);
+
+	do_gettimeofday(&tv);
+
+	/* pasue emi monitor for get WACT value*/
+	mtk_emi_mon_stop(emi->dev);
+
+	val = readl(EMI_WSCT4);	/* GPU BW */
+	val *= 8;
+
+	cur_max = mtk_emi_get_max_bw();
+	emi_update_bw_array(emi->dev, val);
+
+	/* set mew timer expires and restart emi monitor */
+	emi->old_tv = tv;
+	emi->emi_bw_timer.expires = jiffies + msecs_to_jiffies(emi_bw_ms);
+
+	add_timer(&(emi->emi_bw_timer));
+	mtk_emi_mon_restart(emi->dev);
+}
+
+static int emi_probe(struct platform_device *pdev)
+{
+	struct mtk_emi *emi;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	int i, ret;
+
+	emi = devm_kzalloc(dev, sizeof(*emi), GFP_KERNEL);
+	if (!emi)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	emi->cen_emi_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(emi->cen_emi_base)) {
+		pr_err("[EMI] unable to map cen_emi_base\n");
+		devm_kfree(dev, emi);
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	emi->emi_mpu_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(emi->emi_mpu_base)) {
+		pr_err("[EMI] unable to map emi_mpu_base\n");
+		devm_kfree(dev, emi);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < MAX_CH; i++) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 2 + i);
+		emi->chn_emi_base[i] = devm_ioremap_resource(dev, res);
+		if (IS_ERR(emi->chn_emi_base[i])) {
+			pr_err("[EMI] unable to map ch%d_emi_base\n", i);
+			devm_kfree(dev, emi);
+			return -EINVAL;
+		}
+	}
+
+	platform_set_drvdata(pdev, emi);
+	emi->dev = dev;
+
+	/* start emi bw monitor */
+	mtk_emi_mon_start(dev);
+
+	/* setup timer */
+	timer_setup(&(emi->emi_bw_timer), NULL, 0);
+	do_gettimeofday(&(emi->old_tv));
+
+	emi->emi_bw_timer.function = emi_bw_timer_callback;
+	emi->emi_bw_timer.expires = jiffies + msecs_to_jiffies(1);
+	add_timer(&(emi->emi_bw_timer));
+
+	/* debug node */
+	ret = device_create_file(dev, &dev_attr_bw);
+	if (ret) {
+		dev_err(dev, "create bw file failed!\n");
+		goto err_create_attr_bw;
+	}
+	ret = device_create_file(dev, &dev_attr_dump_bw);
+	if (ret) {
+		dev_err(dev, "create dump_bw file failed!\n");
+		goto err_create_attr_dump_bw;
+	}
+
+	return 0;
+
+err_create_attr_dump_bw:
+	del_timer(&(emi->emi_bw_timer));
+	device_remove_file(dev, &dev_attr_bw);
+err_create_attr_bw:
+	devm_kfree(dev, emi);
+	return -ENOMEM;
+}
+
+static int emi_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_emi *emi = dev_get_drvdata(dev);
+
+	del_timer(&(emi->emi_bw_timer));
+	device_remove_file(dev, &dev_attr_dump_bw);
+	device_remove_file(dev, &dev_attr_bw);
+
+	devm_kfree(dev, emi);
+	return 0;
+}
+
+
+#ifdef CONFIG_OF
+static const struct of_device_id emi_of_ids[] = {
+	{.compatible = "mediatek,mt8183-emi",},
+	{}
+};
+#endif
+
+static struct platform_driver emi_bw_driver = {
+	.probe = emi_probe,
+	.remove = emi_remove,
+	.driver = {
+		.name = "emi_bw",
+		.owner = THIS_MODULE,
+		.pm = NULL,
+#ifdef CONFIG_OF
+		.of_match_table = emi_of_ids,
+#endif
+	},
+};
+
+
+static int __init emi_bw_init(void)
+{
+	int ret;
+
+	/* register EMI ctrl interface */
+	ret = platform_driver_register(&emi_bw_driver);
+	if (ret) {
+		pr_err("[EMI/BWL] fail to register emi_bw_driver\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static void __exit emi_bw_exit(void)
+{
+	platform_driver_unregister(&emi_bw_driver);
+}
+
+postcore_initcall(emi_bw_init);
+module_exit(emi_bw_exit);
+
diff --git a/include/soc/mediatek/emi.h b/include/soc/mediatek/emi.h
new file mode 100644
index 0000000..83bdaeb
--- /dev/null
+++ b/include/soc/mediatek/emi.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0  */
+/*
+ * Copyright (c) 2015-2016 MediaTek Inc.
+ * Author: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
+ */
+
+#ifndef _MTK_EMI_H_
+#define _MTK_EMI_H_
+
+#define MAX_CH		2
+#define MAX_RK		2
+
+struct emi_info_t {
+	unsigned int dram_type;
+	unsigned int ch_num;
+	unsigned int rk_num;
+	unsigned int rank_size[MAX_RK];
+};
+
+/*****************************************************************************
+ *  Macro Definiations
+ *****************************************************************************/
+#define EMI_REG_BASE                (0x10219000)
+#define EMI_REG_BASE_MAPPED         (emi->cen_emi_base)
+
+#define EMI_MDCT                    (EMI_REG_BASE_MAPPED + 0x078)
+#define EMI_MDCT_2ND                (EMI_REG_BASE_MAPPED + 0x07C)
+
+#define EMI_ARBA                    (EMI_REG_BASE_MAPPED + 0x100)
+#define EMI_ARBB                    (EMI_REG_BASE_MAPPED + 0x108)
+#define EMI_ARBC                    (EMI_REG_BASE_MAPPED + 0x110)
+#define EMI_ARBD                    (EMI_REG_BASE_MAPPED + 0x118)
+#define EMI_ARBE                    (EMI_REG_BASE_MAPPED + 0x120)
+#define EMI_ARBF                    (EMI_REG_BASE_MAPPED + 0x128)
+#define EMI_ARBG                    (EMI_REG_BASE_MAPPED + 0x130)
+#define EMI_ARBH                    (EMI_REG_BASE_MAPPED + 0x138)
+
+#define EMI_BMEN                    (EMI_REG_BASE_MAPPED + 0x400)
+#define EMI_BCNT                    (EMI_REG_BASE_MAPPED + 0x408)
+#define EMI_TACT                    (EMI_REG_BASE_MAPPED + 0x410)
+#define EMI_TSCT                    (EMI_REG_BASE_MAPPED + 0x418)
+#define EMI_WACT                    (EMI_REG_BASE_MAPPED + 0x420)
+#define EMI_WSCT                    (EMI_REG_BASE_MAPPED + 0x428)
+#define EMI_BACT                    (EMI_REG_BASE_MAPPED + 0x430)
+#define EMI_BSCT                    (EMI_REG_BASE_MAPPED + 0x438)
+#define EMI_MSEL                    (EMI_REG_BASE_MAPPED + 0x440)
+#define EMI_TSCT2                   (EMI_REG_BASE_MAPPED + 0x448)
+#define EMI_TSCT3                   (EMI_REG_BASE_MAPPED + 0x450)
+#define EMI_WSCT2                   (EMI_REG_BASE_MAPPED + 0x458)
+#define EMI_WSCT3                   (EMI_REG_BASE_MAPPED + 0x460)
+#define EMI_WSCT4                   (EMI_REG_BASE_MAPPED + 0x464)
+#define EMI_MSEL2                   (EMI_REG_BASE_MAPPED + 0x468)
+
+#define EMI_BMEN2                   (EMI_REG_BASE_MAPPED + 0x4E8)
+
+#define EMI_BMRW0                   (EMI_REG_BASE_MAPPED + 0x4F8)
+
+#define EMI_TTYPE1                  (EMI_REG_BASE_MAPPED + 0x500)
+#define EMI_TTYPE17                 (EMI_REG_BASE_MAPPED + 0x580)
+
+#define EMI_BWVL                    (EMI_REG_BASE_MAPPED + 0x7D0)
+#define EMI_BWVL_2ND                (EMI_REG_BASE_MAPPED + 0x7D4)
+#define EMI_BWVL_3RD                (EMI_REG_BASE_MAPPED + 0x7D8)
+#define EMI_BWVL_4TH                (EMI_REG_BASE_MAPPED + 0x7DC)
+#define EMI_BWVL_5TH                (EMI_REG_BASE_MAPPED + 0x7E0)
+
+#define EMI_CH0_REG_BASE            (0x1022D000)
+#define EMI_CH0_REG_BASE_MAPPED     (emi->chn_emi_base[0])
+#define EMI_CH0_DRS_ST2             (EMI_CH0_REG_BASE_MAPPED + 0x17C)
+#define EMI_CH0_DRS_ST3             (EMI_CH0_REG_BASE_MAPPED + 0x180)
+#define EMI_CH0_DRS_ST4             (EMI_CH0_REG_BASE_MAPPED + 0x184)
+
+#define EMI_CH1_REG_BASE            (0x10235000)
+#define EMI_CH1_REG_BASE_MAPPED     (emi->chn_emi_base[1])
+#define EMI_CH1_DRS_ST2             (EMI_CH1_REG_BASE_MAPPED + 0x17C)
+#define EMI_CH1_DRS_ST3             (EMI_CH1_REG_BASE_MAPPED + 0x180)
+#define EMI_CH1_DRS_ST4             (EMI_CH1_REG_BASE_MAPPED + 0x184)
+
+/*
+ * DEFAULT_VALUE
+ */
+#define EMI_BMEN_DEFAULT_VALUE    (0x00FF0000)
+#define EMI_BMEN2_DEFAULT_VALUE   (0x02000000)
+#define EMI_BMRW0_DEFAULT_VALUE   (0xFFFFFFFF)
+#define EMI_MSEL_DEFAULT_VALUE    (0x00030024)
+#define EMI_MSEL2_DEFAULT_VALUE   (0x000000C0)
+#define BC_OVERRUN                (0x00000100)
+
+/* EMI_BMEN */
+#define BUS_MON_EN          BIT(0)
+#define BUS_MON_PAUSE       BIT(1)
+#define BUS_MON_IDLE        BIT(3)
+
+#define MAX_DRAM_CH_NUM     (2)
+#define DRAM_RANK_NUM       (2)
+#define DRAM_PDIR_NUM       (8)
+#define EMI_TTYPE_NUM       (21)
+#define EMI_TSCT_NUM        (3)
+#define EMI_MDCT_NUM        (2)
+#define EMI_DRS_ST_NUM      (3)
+#define EMI_BW_LIMIT_NUM    (8)
+
+#define DRAMC_CG_SHIFT      (9)
+
+#define EMI_IDX_SIZE        (1024)
+
+#define EMI_BWVL_UNIT       (271)
+
+#define MBW_BUF_LEN         (0x800000)
+#define DATA_CNT_PER_BLK    (35)
+#define BLK_CNT_PER_BUF     (0x800)
+
+/* public apis */
+unsigned long long emi_get_max_bw(void);
+
+#endif
-- 
1.9.1

Re: [PATCH v2, 3/3] mt8183: emi: add bandwidth driver support

[Hsin-Yi Wang]

On Fri, May 24, 2019 at 3:54 AM Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> wrote:

> +struct mtk_emi {
> +       struct device *dev;
> +       void __iomem *cen_emi_base;
> +       void __iomem *chn_emi_base[MAX_CH];
> +       void __iomem *emi_mpu_base;
> +
> +       struct timer_list emi_bw_timer;
> +       struct timeval old_tv;
> +
> +       unsigned long long emi_bw_array[EMI_BW_ARRAY_SIZE];
> +       int emi_bw_cur_idx;
> +};
> +
> +static unsigned long long emi_get_max_bw_in_last_array(struct device *dev,
> +       unsigned long long arr[], unsigned int size)
> +{
> +       unsigned int i = 0;
> +       unsigned long long max = arr[0];
> +
> +       while (i < size) {
> +               if (arr[i] > max)
> +                       max = arr[i];
> +               ++i;
> +       }
> +       return max;
> +}
Would it better that if we store max element in mtk_emi struct{}, so
that we don't need to scan entire array everytime to find max? Though
array size only 67.
This max element can be update in emi_update_bw_array().

> +unsigned long long mtk_emi_get_max_bw(struct device *dev)
> +{
> +       struct mtk_emi *emi;
> +
> +       if (!dev)
> +               return 0;
> +
> +       emi = dev_get_drvdata(dev);
> +       return emi_get_max_bw_in_last_array(dev,
> +               emi->emi_bw_array, ARRAY_SIZE(emi->emi_bw_array));
> +}
> +EXPORT_SYMBOL(mtk_emi_get_max_bw);
> +
> +static void emi_update_bw_array(struct device *dev, unsigned int val)
> +{
> +       struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +       if (emi->emi_bw_cur_idx == emi->EMI_BW_ARRAY_SIZE) {
> +               /* remove the first array element */
> +               memmove(emi->emi_bw_array, emi->emi_bw_array + 1,
> +                       sizeof(unsigned long long) * (emi->EMI_BW_ARRAY_SIZE - 1));
> +               emi->emi_bw_array[emi->EMI_BW_ARRAY_SIZE - 1] = val;
> +       } else
> +               emi->emi_bw_array[emi->emi_bw_cur_idx++] = val;
> +}
> +
Is the order of the emi_bw_array important?
If not, update latest element don't need to be at the end, so we don't
need O(n) shift everytime when inserting new element.
If the order is important, we can also do insert in O(1), by adding a
pointer that points to the oldest element in array. When insert a new
element, replace oldest element with latest one and move the pointer
one space backward.

Re: [PATCH v2, 3/3] mt8183: emi: add bandwidth driver support

[Xi Chen]

On Tue, 2019-06-18 at 17:40 +0800, Hsin-Yi Wang wrote:
> On Fri, May 24, 2019 at 3:54 AM Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> wrote:
> 
> > +struct mtk_emi {
> > +       struct device *dev;
> > +       void __iomem *cen_emi_base;
> > +       void __iomem *chn_emi_base[MAX_CH];
> > +       void __iomem *emi_mpu_base;
> > +
> > +       struct timer_list emi_bw_timer;
> > +       struct timeval old_tv;
> > +
> > +       unsigned long long emi_bw_array[EMI_BW_ARRAY_SIZE];
> > +       int emi_bw_cur_idx;
> > +};
> > +
> > +static unsigned long long emi_get_max_bw_in_last_array(struct device *dev,
> > +       unsigned long long arr[], unsigned int size)
> > +{
> > +       unsigned int i = 0;
> > +       unsigned long long max = arr[0];
> > +
> > +       while (i < size) {
> > +               if (arr[i] > max)
> > +                       max = arr[i];
> > +               ++i;
> > +       }
> > +       return max;
> > +}
> Would it better that if we store max element in mtk_emi struct{}, so
> that we don't need to scan entire array everytime to find max? Though
> array size only 67.
> This max element can be update in emi_update_bw_array().
	Yes, a good idea. Sorry, v3 doesn't contain the patch. I will try to
improve the codes on v4.
> 
> > +unsigned long long mtk_emi_get_max_bw(struct device *dev)
> > +{
> > +       struct mtk_emi *emi;
> > +
> > +       if (!dev)
> > +               return 0;
> > +
> > +       emi = dev_get_drvdata(dev);
> > +       return emi_get_max_bw_in_last_array(dev,
> > +               emi->emi_bw_array, ARRAY_SIZE(emi->emi_bw_array));
> > +}
> > +EXPORT_SYMBOL(mtk_emi_get_max_bw);
> > +
> > +static void emi_update_bw_array(struct device *dev, unsigned int val)
> > +{
> > +       struct mtk_emi *emi = dev_get_drvdata(dev);
> > +
> > +       if (emi->emi_bw_cur_idx == emi->EMI_BW_ARRAY_SIZE) {
> > +               /* remove the first array element */
> > +               memmove(emi->emi_bw_array, emi->emi_bw_array + 1,
> > +                       sizeof(unsigned long long) * (emi->EMI_BW_ARRAY_SIZE - 1));
> > +               emi->emi_bw_array[emi->EMI_BW_ARRAY_SIZE - 1] = val;
> > +       } else
> > +               emi->emi_bw_array[emi->emi_bw_cur_idx++] = val;
> > +}
> > +
> Is the order of the emi_bw_array important?
> If not, update latest element don't need to be at the end, so we don't
> need O(n) shift everytime when inserting new element.
> If the order is important, we can also do insert in O(1), by adding a
> pointer that points to the oldest element in array. When insert a new
> element, replace oldest element with latest one and move the pointer
> one space backward.
  I understand your idea, but emi driver stores the last 67ms bandwidth,
and just the last 67ms, not all the time. So, we will move the array
elements every 1ms.
> 
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

Re: [PATCH v2, 3/3] mt8183: emi: add bandwidth driver support

[Hsin-Yi Wang]

On Thu, Jul 11, 2019 at 2:43 PM Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> wrote:

>   I understand your idea, but emi driver stores the last 67ms bandwidth,
> and just the last 67ms, not all the time. So, we will move the array
> elements every 1ms.

We can still don't need to move the array elements every 1 ms for
keeping last 67ms.
The idea is like

original:
st                   ed
 |                      |
0, 1, 2, 3, .... 66

insert 67, move st and ed by 1, and 67 inserted to ed position:
ed  st
 |     |
67, 1, 2, 3,... 66

insert 68, move st and ed by 1, and 68 inserted to ed position:
      ed  st
        |   |
67, 68, 2, 3,... 66

But might be more complicated to implement this than current code, and
array size is small, so just an idea for your reference.

Re: [PATCH v2, 3/3] mt8183: emi: add bandwidth driver support

[Matthias Brugger]

On 24/05/2019 05:54, Xi Chen wrote:
> EMI provides interface for get bandwidth  on every 1 miliseconds.
> Currently, just support GPU bandwidth info.
> 
> Signed-off-by: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> ---
>  drivers/memory/Kconfig     |   9 ++
>  drivers/memory/Makefile    |   1 +
>  drivers/memory/mtk-emi.c   | 373 +++++++++++++++++++++++++++++++++++++++++++++
>  include/soc/mediatek/emi.h | 116 ++++++++++++++
>  4 files changed, 499 insertions(+)
>  create mode 100644 drivers/memory/mtk-emi.c
>  create mode 100644 include/soc/mediatek/emi.h
> 
> diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
> index 2d91b00..2a76bfe 100644
> --- a/drivers/memory/Kconfig
> +++ b/drivers/memory/Kconfig
> @@ -129,6 +129,15 @@ config JZ4780_NEMC
>  	  the Ingenic JZ4780. This controller is used to handle external
>  	  memory devices such as NAND and SRAM.
>  
> +config MTK_EMI_MBW
> +	bool "Mediatek EMI bandwidth driver"
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	help
> +	  This driver is for MTK EMI control.
> +	  If unsure, use N.
> +	  This is the first time emi upstream.

That's not a usefull information.

> +	  Only support emi bw statistics.

"The driver supports the EMI bandwith statistics."

> +
>  config MTK_SMI
>  	bool
>  	depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index 90161de..4f8b241 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_FSL_CORENET_CF)	+= fsl-corenet-cf.o
>  obj-$(CONFIG_FSL_IFC)		+= fsl_ifc.o
>  obj-$(CONFIG_MVEBU_DEVBUS)	+= mvebu-devbus.o
>  obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
> +obj-$(CONFIG_MTK_EMI_MBW)	+= mtk-emi.o
>  obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
>  obj-$(CONFIG_DA8XX_DDRCTL)	+= da8xx-ddrctl.o
>  obj-$(CONFIG_PL353_SMC)		+= pl353-smc.o
> diff --git a/drivers/memory/mtk-emi.c b/drivers/memory/mtk-emi.c
> new file mode 100644
> index 0000000..acbe5a6
> --- /dev/null
> +++ b/drivers/memory/mtk-emi.c
> @@ -0,0 +1,373 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2019 MediaTek Inc.
> + * Author: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> + */
> +
> +#include <linux/cdev.h>
> +#include <linux/clk.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/fs.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/time.h>
> +#include <linux/timer.h>
> +#include <soc/mediatek/emi.h>

Do we really need all of them?

> +
> +/* 67ms emi bw  */
> +#define EMI_BW_ARRAY_SIZE	67
> +
> +struct mtk_emi {
> +	struct device *dev;
> +	void __iomem *cen_emi_base;
> +	void __iomem *chn_emi_base[MAX_CH];
> +	void __iomem *emi_mpu_base;
> +

name them with consistency, e.g.:
emi_cen_base
emi_chn_base
emi_mpu_base

actually only one base is used in the driver.

> +	struct timer_list emi_bw_timer;
> +	struct timeval old_tv;
> +
> +	unsigned long long emi_bw_array[EMI_BW_ARRAY_SIZE];
> +	int emi_bw_cur_idx;
> +};
> +
> +static unsigned long long emi_get_max_bw_in_last_array(struct device *dev,
> +	unsigned long long arr[], unsigned int size)

folds this function int mtk_emi_get_max_bw.

> +{
> +	unsigned int i = 0;
> +	unsigned long long max = arr[0];
> +
> +	while (i < size) {

I'd prefer a for loop.

> +		if (arr[i] > max)
> +			max = arr[i];

max = max(arr[i], max);

> +		++i;
> +	}
> +	return max;
> +}
> +
> +unsigned long long mtk_emi_get_max_bw(struct device *dev)
> +{
> +	struct mtk_emi *emi;
> +
> +	if (!dev)
> +		return 0;
> +
> +	emi = dev_get_drvdata(dev);
> +	return emi_get_max_bw_in_last_array(dev,
> +		emi->emi_bw_array, ARRAY_SIZE(emi->emi_bw_array));
> +}
> +EXPORT_SYMBOL(mtk_emi_get_max_bw);
> +
> +static void emi_update_bw_array(struct device *dev, unsigned int val)
> +{
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	if (emi->emi_bw_cur_idx == emi->EMI_BW_ARRAY_SIZE) {

EMI_BW_ARRAY_SIZE is a define not a struct member. Please don't send random code
which you haven't even tried to compile. The patches you send should compile and
provide a working driver against upstream linux kernel.

Some more comments below, although I didn't look deeply through the whole code,
as I have the feeling that this driver was never tested. Please do so and resubmit.

> +		/* remove the first array element */
> +		memmove(emi->emi_bw_array, emi->emi_bw_array + 1,
> +			sizeof(unsigned long long) * (emi->EMI_BW_ARRAY_SIZE - 1));
> +		emi->emi_bw_array[emi->EMI_BW_ARRAY_SIZE - 1] = val;
> +	} else
> +		emi->emi_bw_array[emi->emi_bw_cur_idx++] = val;
> +}
> +
> +static void emi_dump_bw_array(struct device *dev)
> +{
> +	int i = 0;
> +	const int unit = 10;
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	while (i < emi->EMI_BW_ARRAY_SIZE) {
> +		if (i != 0 && i % unit == 0)
> +			pr_info("\n");
> +		pr_info("0x%x ", emi->emi_bw_array[i]);
> +
> +		++i;
> +	}
> +
> +	pr_info("\n");
> +}
> +
> +static void emi_counter_reset(struct device *dev)
> +{
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	writel(EMI_BMEN_DEFAULT_VALUE, EMI_BMEN);
> +	writel(EMI_MSEL_DEFAULT_VALUE, EMI_MSEL);
> +	writel(EMI_MSEL2_DEFAULT_VALUE, EMI_MSEL2);
> +	writel(EMI_BMEN2_DEFAULT_VALUE, EMI_BMEN2);
> +	writel(EMI_BMRW0_DEFAULT_VALUE, EMI_BMRW0);
> +}
> +
> +static void emi_counter_pause(struct device *dev)
> +{
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +	const unsigned int value = readl(EMI_BMEN);
> +
> +	/* BW monitor */
> +	writel(value | BUS_MON_PAUSE, EMI_BMEN);
> +}
> +
> +static void emi_counter_continue(struct device *dev)
> +{
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +	const unsigned int value = readl(EMI_BMEN);
> +
> +	/* BW monitor */
> +	writel(value & (~BUS_MON_PAUSE), EMI_BMEN);
> +}
> +
> +static void emi_counter_enable(struct device *dev, const unsigned int enable)
> +{
> +	unsigned int value, value_set;
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	value = readl(EMI_BMEN);
> +	if (!enable) {	/* disable monitor circuit */
> +		/*  bit3 =1	bit0 = 0-> clear */
> +		value_set = (value) | (BUS_MON_IDLE);
> +		writel(value_set, EMI_BMEN);
> +
> +		value_set = ((value) | (BUS_MON_IDLE)) & ~(BUS_MON_EN);
> +		writel(value_set, EMI_BMEN);
> +
> +		value_set = ((value) & ~(BUS_MON_IDLE)) & ~(BUS_MON_EN);
> +		writel(value_set, EMI_BMEN);
> +	} else {		/* enable monitor circuit */
> +		/*  bit3 =0	&   bit0=1 */
> +		value_set = (value & ~(BUS_MON_IDLE));
> +		writel(value_set, EMI_BMEN);
> +
> +		value_set = (value & ~(BUS_MON_IDLE)) | (BUS_MON_EN);
> +		writel(value_set, EMI_BMEN);
> +	}
> +}
> +
> +/*****************************************************************************
> + *  APIs
> + *****************************************************************************/
> +static void mtk_emi_mon_start(struct device *dev)
> +{
> +	emi_counter_enable(dev, 0);
> +	emi_counter_reset(dev);
> +	emi_counter_enable(dev, 1);
> +}
> +
> +static void mtk_emi_mon_restart(struct device *dev)
> +{
> +	emi_counter_continue(dev);
> +	emi_counter_enable(dev, 0);
> +	emi_counter_reset(dev);
> +	emi_counter_enable(dev, 1);
> +}
> +
> +static void mtk_emi_mon_stop(struct device *dev)
> +{
> +	emi_counter_pause(dev);
> +}
> +
> +static ssize_t emi_show_max_bw(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	unsigned long long var, bw_cpu;
> +	unsigned int bw_gpu;
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	if (!dev) {
> +		pr_warn("dev is null!!\n");
> +		return 0;
> +	}
> +
> +	var = mtk_emi_get_max_bw();

Does this actually compile?

> +	bw_gpu = readl(EMI_BWVL_4TH) & 0x7f;
> +	bw_cpu = readl(EMI_WSCT3);
> +
> +	return scnprintf(buf, PAGE_SIZE,
> +		"gpu_max_bw:%llu(0x%x) EMI_BWVL_4TH:0x%x, cpu:%llu(0x%x)\n",
> +		var, var, bw_gpu, bw_cpu, bw_cpu);
> +}
> +
> +DEVICE_ATTR(bw,  0440, emi_show_max_bw, NULL);
> +
> +static ssize_t emi_dump_bw(struct device *dev, struct device_attribute *attr,
> +			   char *buf)
> +{
> +	unsigned long long var;
> +
> +	if (!dev) {
> +		pr_warn("dev is null!!\n");
> +		return 0;
> +	}
> +
> +	emi_dump_bw_array(dev);
> +	var = mtk_emi_get_max_bw();
> +
> +	return scnprintf(buf, PAGE_SIZE,
> +		"\temi_max_bw:%llu(0x%x)\n", var, var);
> +}
> +
> +DEVICE_ATTR(dump_bw,  0440, emi_dump_bw, NULL);
> +
> +static int emi_bw_ms = 1;
> +module_param_named(bw_ms, emi_bw_ms, int, 0664);
> +
> +static void emi_bw_timer_callback(struct timer_list *tm)
> +{
> +	struct timeval tv;
> +	unsigned long long val, cur_max;
> +	struct mtk_emi *emi = from_timer(mtk_emi, tm, emi_bw_timer);
> +
> +	do_gettimeofday(&tv);
> +
> +	/* pasue emi monitor for get WACT value*/
> +	mtk_emi_mon_stop(emi->dev);
> +
> +	val = readl(EMI_WSCT4);	/* GPU BW */
> +	val *= 8;
> +
> +	cur_max = mtk_emi_get_max_bw();
> +	emi_update_bw_array(emi->dev, val);
> +
> +	/* set mew timer expires and restart emi monitor */
> +	emi->old_tv = tv;
> +	emi->emi_bw_timer.expires = jiffies + msecs_to_jiffies(emi_bw_ms);
> +
> +	add_timer(&(emi->emi_bw_timer));
> +	mtk_emi_mon_restart(emi->dev);
> +}
> +
> +static int emi_probe(struct platform_device *pdev)
> +{
> +	struct mtk_emi *emi;
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	int i, ret;
> +
> +	emi = devm_kzalloc(dev, sizeof(*emi), GFP_KERNEL);
> +	if (!emi)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	emi->cen_emi_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(emi->cen_emi_base)) {
> +		pr_err("[EMI] unable to map cen_emi_base\n");
> +		devm_kfree(dev, emi);
> +		return -EINVAL;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +	emi->emi_mpu_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(emi->emi_mpu_base)) {
> +		pr_err("[EMI] unable to map emi_mpu_base\n");
> +		devm_kfree(dev, emi);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < MAX_CH; i++) {
> +		res = platform_get_resource(pdev, IORESOURCE_MEM, 2 + i);
> +		emi->chn_emi_base[i] = devm_ioremap_resource(dev, res);
> +		if (IS_ERR(emi->chn_emi_base[i])) {
> +			pr_err("[EMI] unable to map ch%d_emi_base\n", i);
> +			devm_kfree(dev, emi);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	platform_set_drvdata(pdev, emi);
> +	emi->dev = dev;
> +
> +	/* start emi bw monitor */
> +	mtk_emi_mon_start(dev);
> +
> +	/* setup timer */
> +	timer_setup(&(emi->emi_bw_timer), NULL, 0);
> +	do_gettimeofday(&(emi->old_tv));
> +
> +	emi->emi_bw_timer.function = emi_bw_timer_callback;
> +	emi->emi_bw_timer.expires = jiffies + msecs_to_jiffies(1);
> +	add_timer(&(emi->emi_bw_timer));
> +
> +	/* debug node */
> +	ret = device_create_file(dev, &dev_attr_bw);
> +	if (ret) {
> +		dev_err(dev, "create bw file failed!\n");
> +		goto err_create_attr_bw;
> +	}
> +	ret = device_create_file(dev, &dev_attr_dump_bw);
> +	if (ret) {
> +		dev_err(dev, "create dump_bw file failed!\n");
> +		goto err_create_attr_dump_bw;
> +	}
> +
> +	return 0;
> +
> +err_create_attr_dump_bw:
> +	del_timer(&(emi->emi_bw_timer));
> +	device_remove_file(dev, &dev_attr_bw);
> +err_create_attr_bw:
> +	devm_kfree(dev, emi);
> +	return -ENOMEM;
> +}
> +
> +static int emi_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mtk_emi *emi = dev_get_drvdata(dev);
> +
> +	del_timer(&(emi->emi_bw_timer));
> +	device_remove_file(dev, &dev_attr_dump_bw);
> +	device_remove_file(dev, &dev_attr_bw);
> +
> +	devm_kfree(dev, emi);
> +	return 0;
> +}
> +
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id emi_of_ids[] = {
> +	{.compatible = "mediatek,mt8183-emi",},
> +	{}
> +};
> +#endif
> +
> +static struct platform_driver emi_bw_driver = {
> +	.probe = emi_probe,
> +	.remove = emi_remove,
> +	.driver = {
> +		.name = "emi_bw",
> +		.owner = THIS_MODULE,
> +		.pm = NULL,
> +#ifdef CONFIG_OF
> +		.of_match_table = emi_of_ids,
> +#endif
> +	},
> +};
> +
> +
> +static int __init emi_bw_init(void)
> +{
> +	int ret;
> +
> +	/* register EMI ctrl interface */
> +	ret = platform_driver_register(&emi_bw_driver);
> +	if (ret) {
> +		pr_err("[EMI/BWL] fail to register emi_bw_driver\n");
> +		return -ENODEV;
> +	}
> +
> +	return 0;
> +}
> +
> +static void __exit emi_bw_exit(void)
> +{
> +	platform_driver_unregister(&emi_bw_driver);
> +}
> +
> +postcore_initcall(emi_bw_init);
> +module_exit(emi_bw_exit);
> +
> diff --git a/include/soc/mediatek/emi.h b/include/soc/mediatek/emi.h
> new file mode 100644
> index 0000000..83bdaeb
> --- /dev/null
> +++ b/include/soc/mediatek/emi.h
> @@ -0,0 +1,116 @@
> +/* SPDX-License-Identifier: GPL-2.0  */
> +/*
> + * Copyright (c) 2015-2016 MediaTek Inc.
> + * Author: Xi Chen <xixi.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> + */
> +
> +#ifndef _MTK_EMI_H_
> +#define _MTK_EMI_H_
> +
> +#define MAX_CH		2
> +#define MAX_RK		2
> +
> +struct emi_info_t {

why do you use _t postfix? It's not a typedef, right?

> +	unsigned int dram_type;
> +	unsigned int ch_num;
> +	unsigned int rk_num;
> +	unsigned int rank_size[MAX_RK];
> +};
> +
> +/*****************************************************************************
> + *  Macro Definiations
> + *****************************************************************************/

No need for this comment.

> +#define EMI_REG_BASE                (0x10219000)

not used here. actually the base address should always come from DTS.

> +#define EMI_REG_BASE_MAPPED         (emi->cen_emi_base)
> +

we want to use the base with emi->emi_cen_base in the driver

> +#define EMI_MDCT                    (EMI_REG_BASE_MAPPED + 0x078)
> +#define EMI_MDCT_2ND                (EMI_REG_BASE_MAPPED + 0x07C)
> +
> +#define EMI_ARBA                    (EMI_REG_BASE_MAPPED + 0x100)
> +#define EMI_ARBB                    (EMI_REG_BASE_MAPPED + 0x108)
> +#define EMI_ARBC                    (EMI_REG_BASE_MAPPED + 0x110)
> +#define EMI_ARBD                    (EMI_REG_BASE_MAPPED + 0x118)
> +#define EMI_ARBE                    (EMI_REG_BASE_MAPPED + 0x120)
> +#define EMI_ARBF                    (EMI_REG_BASE_MAPPED + 0x128)
> +#define EMI_ARBG                    (EMI_REG_BASE_MAPPED + 0x130)
> +#define EMI_ARBH                    (EMI_REG_BASE_MAPPED + 0x138)
> +
> +#define EMI_BMEN                    (EMI_REG_BASE_MAPPED + 0x400)
> +#define EMI_BCNT                    (EMI_REG_BASE_MAPPED + 0x408)
> +#define EMI_TACT                    (EMI_REG_BASE_MAPPED + 0x410)
> +#define EMI_TSCT                    (EMI_REG_BASE_MAPPED + 0x418)
> +#define EMI_WACT                    (EMI_REG_BASE_MAPPED + 0x420)
> +#define EMI_WSCT                    (EMI_REG_BASE_MAPPED + 0x428)
> +#define EMI_BACT                    (EMI_REG_BASE_MAPPED + 0x430)
> +#define EMI_BSCT                    (EMI_REG_BASE_MAPPED + 0x438)
> +#define EMI_MSEL                    (EMI_REG_BASE_MAPPED + 0x440)
> +#define EMI_TSCT2                   (EMI_REG_BASE_MAPPED + 0x448)
> +#define EMI_TSCT3                   (EMI_REG_BASE_MAPPED + 0x450)
> +#define EMI_WSCT2                   (EMI_REG_BASE_MAPPED + 0x458)
> +#define EMI_WSCT3                   (EMI_REG_BASE_MAPPED + 0x460)
> +#define EMI_WSCT4                   (EMI_REG_BASE_MAPPED + 0x464)
> +#define EMI_MSEL2                   (EMI_REG_BASE_MAPPED + 0x468)
> +
> +#define EMI_BMEN2                   (EMI_REG_BASE_MAPPED + 0x4E8)
> +
> +#define EMI_BMRW0                   (EMI_REG_BASE_MAPPED + 0x4F8)
> +
> +#define EMI_TTYPE1                  (EMI_REG_BASE_MAPPED + 0x500)
> +#define EMI_TTYPE17                 (EMI_REG_BASE_MAPPED + 0x580)
> +
> +#define EMI_BWVL                    (EMI_REG_BASE_MAPPED + 0x7D0)
> +#define EMI_BWVL_2ND                (EMI_REG_BASE_MAPPED + 0x7D4)
> +#define EMI_BWVL_3RD                (EMI_REG_BASE_MAPPED + 0x7D8)
> +#define EMI_BWVL_4TH                (EMI_REG_BASE_MAPPED + 0x7DC)
> +#define EMI_BWVL_5TH                (EMI_REG_BASE_MAPPED + 0x7E0)
> +
> +#define EMI_CH0_REG_BASE            (0x1022D000)
> +#define EMI_CH0_REG_BASE_MAPPED     (emi->chn_emi_base[0])
> +#define EMI_CH0_DRS_ST2             (EMI_CH0_REG_BASE_MAPPED + 0x17C)
> +#define EMI_CH0_DRS_ST3             (EMI_CH0_REG_BASE_MAPPED + 0x180)
> +#define EMI_CH0_DRS_ST4             (EMI_CH0_REG_BASE_MAPPED + 0x184)
> +
> +#define EMI_CH1_REG_BASE            (0x10235000)
> +#define EMI_CH1_REG_BASE_MAPPED     (emi->chn_emi_base[1])
> +#define EMI_CH1_DRS_ST2             (EMI_CH1_REG_BASE_MAPPED + 0x17C)
> +#define EMI_CH1_DRS_ST3             (EMI_CH1_REG_BASE_MAPPED + 0x180)
> +#define EMI_CH1_DRS_ST4             (EMI_CH1_REG_BASE_MAPPED + 0x184)
> +

Many unused define. Also, we usually use the offset as define and write our code
like this:
writel(value, emi->base + EMI_MSEL2);

Regards,
Matthias

> +/*
> + * DEFAULT_VALUE
> + */
> +#define EMI_BMEN_DEFAULT_VALUE    (0x00FF0000)
> +#define EMI_BMEN2_DEFAULT_VALUE   (0x02000000)
> +#define EMI_BMRW0_DEFAULT_VALUE   (0xFFFFFFFF)
> +#define EMI_MSEL_DEFAULT_VALUE    (0x00030024)
> +#define EMI_MSEL2_DEFAULT_VALUE   (0x000000C0)
> +#define BC_OVERRUN                (0x00000100)
> +
> +/* EMI_BMEN */
> +#define BUS_MON_EN          BIT(0)
> +#define BUS_MON_PAUSE       BIT(1)
> +#define BUS_MON_IDLE        BIT(3)
> +
> +#define MAX_DRAM_CH_NUM     (2)
> +#define DRAM_RANK_NUM       (2)
> +#define DRAM_PDIR_NUM       (8)
> +#define EMI_TTYPE_NUM       (21)
> +#define EMI_TSCT_NUM        (3)
> +#define EMI_MDCT_NUM        (2)
> +#define EMI_DRS_ST_NUM      (3)
> +#define EMI_BW_LIMIT_NUM    (8)
> +
> +#define DRAMC_CG_SHIFT      (9)
> +
> +#define EMI_IDX_SIZE        (1024)
> +
> +#define EMI_BWVL_UNIT       (271)
> +
> +#define MBW_BUF_LEN         (0x800000)
> +#define DATA_CNT_PER_BLK    (35)
> +#define BLK_CNT_PER_BUF     (0x800)
> +
> +/* public apis */
> +unsigned long long emi_get_max_bw(void);
> +
> +#endif
>