LinuxLists.cc - [PATCH 0/3] ARM: da850: new drivers for better LCDC support

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Subject: [PATCH 3/3] ARM: dts: da850: add the syscfg and ddrctl nodes

Add the nodes for the System Configuration and DDR2/mDDR memory
controller drivers to da850.dtsi.

Signed-off-by: Bartosz Golaszewski <[email protected]>
---
arch/arm/boot/dts/da850.dtsi | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/da850.dtsi b/arch/arm/boot/dts/da850.dtsi
index 6440002..6d56ef2 100644
--- a/arch/arm/boot/dts/da850.dtsi
+++ b/arch/arm/boot/dts/da850.dtsi
@@ -407,6 +407,16 @@
interrupts = <52>;
status = "disabled";
};
+
+ ddrctl: da850-ddrctl {
+ compatible = "ti,da850-ddrctl";
+ status = "disabled";
+ };
+
+ syscfg: da850-syscfg {
+ compatible = "ti,da850-syscfg";
+ status = "disabled";
+ };
};
aemif: aemif@68000000 {
compatible = "ti,da850-aemif";
--
2.9.3

2016-10-17 16:31:37

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Subject: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

Create the driver for the da8xx System Configuration and implement
support for writing to the three Master Priority registers.

Signed-off-by: Bartosz Golaszewski <[email protected]>
---
.../devicetree/bindings/bus/ti,da850-syscfg.txt | 63 +++++++
drivers/bus/Kconfig | 8 +
drivers/bus/Makefile | 2 +
drivers/bus/da8xx-syscfg.c | 206 +++++++++++++++++++++
4 files changed, 279 insertions(+)
create mode 100644 Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
create mode 100644 drivers/bus/da8xx-syscfg.c

diff --git a/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
new file mode 100644
index 0000000..07e5c38
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
@@ -0,0 +1,63 @@
+* Device tree bindings for Texas Instruments da8xx system configuration driver
+
+The system configuration (SYSCFG) module is a system-level module containing
+status and top level control logic required by the device. The system
+configuration module consists of a set of memory-mapped status and control
+registers, accessible by the CPU, supporting all of the following system
+features, and miscellaneous functions and operations.
+
+Documentation:
+OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
+
+Required properties:
+
+- compatible: "ti,da850-syscfg"
+
+Optional properties:
+
+The below properties are used to specify the priority of master peripherals.
+They must be between 0-7 where 0 is the highest priority and 7 is the lowest.
+
+- ti,pri-arm-i: ARM_I port priority.
+
+- ti,pri-arm-d: ARM_D port priority.
+
+- ti,pri-upp: uPP port priority.
+
+- ti,pri-sata: SATA port priority.
+
+- ti,pri-pru0: PRU0 port priority.
+
+- ti,pri-pru1: PRU1 port priority.
+
+- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
+
+- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
+
+- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
+
+- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
+
+- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
+
+- ti,pri-emac: EMAC port priority.
+
+- ti,pri-usb0cfg: USB0 CFG port priority.
+
+- ti,pri-usb0cdma: USB0 CDMA port priority.
+
+- ti,pri-uhpi: HPI port priority.
+
+- ti,pri-usb1: USB1 port priority.
+
+- ti,pri-lcdc: LCDC port priority.
+
+If any of the above properties is absent, the default value will be used as
+defined in the documentation.
+
+Example for da850-lcdk is shown below.
+
+mstpri {
+ compatible = "ti,da850-mstpri";
+ ti,pri-lcdc = 0;
+};
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 5a2d47c..6276132 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -165,4 +165,12 @@ config VEXPRESS_CONFIG
help
Platform configuration infrastructure for the ARM Ltd.
Versatile Express.
+
+config DA8XX_SYSCFG
+ bool "TI da8xx system configuration driver"
+ depends on ARCH_DAVINCI_DA8XX
+ help
+ Driver for Texas Instruments da8xx system configuration. Allows to
+ adjust various SoC configuration options.
+
endmenu
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index c6cfa6b..3cba66a 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -21,3 +21,5 @@ obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o
obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
+
+obj-$(CONFIG_DA8XX_SYSCFG) += da8xx-syscfg.o
diff --git a/drivers/bus/da8xx-syscfg.c b/drivers/bus/da8xx-syscfg.c
new file mode 100644
index 0000000..8a2cb4f
--- /dev/null
+++ b/drivers/bus/da8xx-syscfg.c
@@ -0,0 +1,206 @@
+/*
+ * TI da8xx System Configuration driver
+ *
+ * Copyright (C) 2016 BayLibre SAS
+ *
+ * Author:
+ * Bartosz Golaszewski <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#define DA8XX_IO_PHYS 0x01c00000ul
+#define DA8XX_SYSCFG0_BASE (DA8XX_IO_PHYS + 0x14000)
+
+#define DA8XX_MSTPRI0_REG 0x110
+#define DA8XX_MSTPRI1_REG 0x114
+#define DA8XX_MSTPRI2_REG 0x118
+
+#define DA8XX_MSTPRI_MAX 7
+
+struct da8xx_mstpri_descr {
+ const char *property;
+ int reg;
+ int shift;
+ int mask;
+};
+
+static const struct da8xx_mstpri_descr priorities[] = {
+ {
+ .property = "ti,pri-arm-i",
+ .reg = DA8XX_MSTPRI0_REG,
+ .shift = 0,
+ .mask = 0xfffffff0,
+ },
+ {
+ .property = "ti,pri-arm-d",
+ .reg = DA8XX_MSTPRI0_REG,
+ .shift = 4,
+ .mask = 0xffffff0f,
+ },
+ {
+ .property = "ti,pri-upp",
+ .reg = DA8XX_MSTPRI0_REG,
+ .shift = 16,
+ .mask = 0xfff0ffff,
+ },
+ {
+ .property = "ti,pri-sata",
+ .reg = DA8XX_MSTPRI0_REG,
+ .shift = 20,
+ .mask = 0xff0fffff,
+ },
+ {
+ .property = "ti,pri-pru0",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 0,
+ .mask = 0xfffffff0,
+ },
+ {
+ .property = "ti,pri-pru1",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 4,
+ .mask = 0xffffff0f,
+ },
+ {
+ .property = "ti,pri-edma30tc0",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 8,
+ .mask = 0xfffff0ff,
+ },
+ {
+ .property = "ti,pri-edma30tc1",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 12,
+ .mask = 0xffff0fff,
+ },
+ {
+ .property = "ti,pri-edma31tc0",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 16,
+ .mask = 0xfff0ffff,
+ },
+ {
+ .property = "ti,pri-vpif-dma-0",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 24,
+ .mask = 0xf0ffffff,
+ },
+ {
+ .property = "ti,pri-vpif-dma-1",
+ .reg = DA8XX_MSTPRI1_REG,
+ .shift = 28,
+ .mask = 0x0fffffff,
+ },
+ {
+ .property = "ti,pri-emac",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 0,
+ .mask = 0xfffffff0,
+ },
+ {
+ .property = "ti,pri-usb0cfg",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 8,
+ .mask = 0xfffff0ff,
+ },
+ {
+ .property = "ti,pri-usb0cdma",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 12,
+ .mask = 0xffff0fff,
+ },
+ {
+ .property = "ti,pri-uhpi",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 20,
+ .mask = 0xff0fffff,
+ },
+ {
+ .property = "ti,pri-usb1",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 24,
+ .mask = 0xf0ffffff,
+ },
+ {
+ .property = "ti,pri-lcdc",
+ .reg = DA8XX_MSTPRI2_REG,
+ .shift = 28,
+ .mask = 0x0fffffff,
+ },
+};
+
+static void da8xx_syscfg_set_mstpri(void __iomem *syscfg0, struct device *dev)
+{
+ const struct da8xx_mstpri_descr *pri_descr;
+ struct device_node *node = dev->of_node;
+ void __iomem *mstpri;
+ u32 old_pri, new_pri;
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(priorities); i++) {
+ pri_descr = &priorities[i];
+
+ ret = of_property_read_u32(node, pri_descr->property, &new_pri);
+ if (ret)
+ continue;
+
+ if (new_pri > DA8XX_MSTPRI_MAX) {
+ dev_warn(dev,
+ "omitting property '%s' - value too high\n",
+ pri_descr->property);
+ continue;
+ }
+
+ mstpri = syscfg0 + pri_descr->reg;
+ old_pri = __raw_readl(mstpri);
+ old_pri &= pri_descr->mask;
+ new_pri <<= pri_descr->shift;
+ new_pri |= old_pri;
+
+ __raw_writel(new_pri, mstpri);
+ }
+}
+
+static int da8xx_syscfg_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ void __iomem *syscfg0;
+
+ syscfg0 = ioremap(DA8XX_SYSCFG0_BASE, SZ_4K);
+ if (!syscfg0) {
+ dev_err(dev, "unable to map syscfg0\n");
+ return -EIO;
+ }
+
+ da8xx_syscfg_set_mstpri(syscfg0, dev);
+
+ iounmap(syscfg0);
+
+ return 0;
+}
+
+static const struct of_device_id da8xx_syscfg_of_match[] = {
+ { .compatible = "ti,da850-syscfg", },
+ { },
+};
+
+static struct platform_driver da8xx_syscfg_driver = {
+ .probe = da8xx_syscfg_probe,
+ .driver = {
+ .name = "da8xx-syscfg",
+ .of_match_table = da8xx_syscfg_of_match,
+ },
+};
+module_platform_driver(da8xx_syscfg_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <[email protected]>");
+MODULE_DESCRIPTION("TI da8xx System Configuration driver");
+MODULE_LICENSE("GPL v2");
--
2.9.3

2016-10-17 16:31:46

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Subject: [PATCH 1/3] ARM: memory: da8xx-ddrctl: new driver

Create a new driver for the da8xx DDR2/mDDR controller and implement
support for writing to the Peripheral Bus Burst Priority Register.

Signed-off-by: Bartosz Golaszewski <[email protected]>
---
.../memory-controllers/ti-da8xx-ddrctl.txt | 25 +++++++
drivers/memory/Kconfig | 8 +++
drivers/memory/Makefile | 1 +
drivers/memory/da8xx-ddrctl.c | 77 ++++++++++++++++++++++
4 files changed, 111 insertions(+)
create mode 100644 Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
create mode 100644 drivers/memory/da8xx-ddrctl.c

diff --git a/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
new file mode 100644
index 0000000..e340404
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
@@ -0,0 +1,25 @@
+* Device tree bindings for Texas Instruments da8xx DDR2/mDDR memory controller
+
+The DDR2/mDDR memory controller present on Texas Instruments da8xx SoCs memory
+maps a set of registers which allow to tweak the controller's behavior.
+
+Documentation:
+OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
+
+Required properties:
+
+- compatible: "ti,da850-ddrctl"
+
+Optional properties:
+
+- ti,pr-old-count: Priority raise old counter. Specifies the number of
+ memory transfers after which the DDR2/mDDR memory
+ controller will elevate the priority of the oldest
+ command in the command FIFO. Must be between 0-255.
+
+Example for da850 shown below.
+
+ddrctl {
+ compatible = "ti,da850-ddrctl";
+ ti,pr-old-count = <0x20>;
+};
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 4b4c0c3..ec80e35 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -134,6 +134,14 @@ config MTK_SMI
mainly help enable/disable iommu and control the power domain and
clocks for each local arbiter.

+config DA8XX_DDRCTL
+ bool "Texas Instruments da8xx DDR2/mDDR driver"
+ depends on ARCH_DAVINCI_DA8XX
+ help
+ This driver is for the DDR2/mDDR Memory Controller present on
+ Texas Instruments da8xx SoCs. It's used to tweak various memory
+ controller configuration options.
+
source "drivers/memory/samsung/Kconfig"
source "drivers/memory/tegra/Kconfig"

diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index b20ae38..e88097fb 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
obj-$(CONFIG_JZ4780_NEMC) += jz4780-nemc.o
obj-$(CONFIG_MTK_SMI) += mtk-smi.o
+obj-$(CONFIG_DA8XX_DDRCTL) += da8xx-ddrctl.o

obj-$(CONFIG_SAMSUNG_MC) += samsung/
obj-$(CONFIG_TEGRA_MC) += tegra/
diff --git a/drivers/memory/da8xx-ddrctl.c b/drivers/memory/da8xx-ddrctl.c
new file mode 100644
index 0000000..dcd0a61
--- /dev/null
+++ b/drivers/memory/da8xx-ddrctl.c
@@ -0,0 +1,77 @@
+/*
+ * TI da8xx DDR2/mDDR controller driver
+ *
+ * Copyright (C) 2016 BayLibre SAS
+ *
+ * Author:
+ * Bartosz Golaszewski <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#define DA8XX_DDR_CTL_BASE 0xB0000000
+#define DA8XX_PBBPR_OFFSET 0x00000020
+#define DA8XX_PBBPR_REG(p) ((p) + DA8XX_PBBPR_OFFSET)
+
+#define DA8XX_PBBPR_MAX 0xff
+
+static void da8xx_ddrctl_set_pbbpr(void __iomem *ddrctl, struct device *dev)
+{
+ struct device_node *node = dev->of_node;
+ u32 pr_old_count;
+ int ret;
+
+ ret = of_property_read_u32(node, "ti,pr-old-count", &pr_old_count);
+ if (ret)
+ return;
+
+ if (pr_old_count > DA8XX_PBBPR_MAX) {
+ dev_warn(dev, "priority raise old counter value too high\n");
+ return;
+ }
+
+ __raw_writel(pr_old_count, DA8XX_PBBPR_REG(ddrctl));
+}
+
+static int da8xx_ddrctl_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ void __iomem *ddrctl;
+
+ ddrctl = ioremap(DA8XX_DDR_CTL_BASE, SZ_256);
+ if (!ddrctl) {
+ dev_err(dev, "unable to map memory controller registers\n");
+ return -EIO;
+ }
+
+ da8xx_ddrctl_set_pbbpr(ddrctl, dev);
+
+ iounmap(ddrctl);
+
+ return 0;
+}
+
+static const struct of_device_id da8xx_ddrctl_of_match[] = {
+ { .compatible = "ti,da850-ddrctl", },
+ { },
+};
+
+static struct platform_driver da8xx_ddrctl_driver = {
+ .probe = da8xx_ddrctl_probe,
+ .driver = {
+ .name = "da8xx-ddrctl",
+ .of_match_table = da8xx_ddrctl_of_match,
+ },
+};
+module_platform_driver(da8xx_ddrctl_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <[email protected]>");
+MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
+MODULE_LICENSE("GPL v2");
--
2.9.3

2016-10-17 16:55:15

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Subject: Re: [PATCH 1/3] ARM: memory: da8xx-ddrctl: new driver

Bartosz Golaszewski <[email protected]> writes:

> Create a new driver for the da8xx DDR2/mDDR controller and implement
> support for writing to the Peripheral Bus Burst Priority Register.
>
> Signed-off-by: Bartosz Golaszewski <[email protected]>

[...]

> diff --git a/drivers/memory/da8xx-ddrctl.c b/drivers/memory/da8xx-ddrctl.c
> new file mode 100644
> index 0000000..dcd0a61
> --- /dev/null
> +++ b/drivers/memory/da8xx-ddrctl.c
> @@ -0,0 +1,77 @@
> +/*
> + * TI da8xx DDR2/mDDR controller driver
> + *
> + * Copyright (C) 2016 BayLibre SAS
> + *
> + * Author:
> + * Bartosz Golaszewski <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +
> +#define DA8XX_DDR_CTL_BASE 0xB0000000

This base addr should be the reg property of the node.

> +#define DA8XX_PBBPR_OFFSET 0x00000020
> +#define DA8XX_PBBPR_REG(p) ((p) + DA8XX_PBBPR_OFFSET)

Kevin

2016-10-17 17:01:30

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Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

Bartosz Golaszewski <[email protected]> writes:

> Create the driver for the da8xx System Configuration and implement
> support for writing to the three Master Priority registers.
>
> Signed-off-by: Bartosz Golaszewski <[email protected]>

[...]

> +#define DA8XX_IO_PHYS 0x01c00000ul
> +#define DA8XX_SYSCFG0_BASE (DA8XX_IO_PHYS + 0x14000)

The base addr should come from DT.

Kevin

2016-10-18 20:45:49

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Subject: Re: [PATCH 1/3] ARM: memory: da8xx-ddrctl: new driver

Hi Bartosz,

Thank you for the patch.

On Monday 17 Oct 2016 18:30:48 Bartosz Golaszewski wrote:
> Create a new driver for the da8xx DDR2/mDDR controller and implement
> support for writing to the Peripheral Bus Burst Priority Register.
>
> Signed-off-by: Bartosz Golaszewski <[email protected]>
> ---
> .../memory-controllers/ti-da8xx-ddrctl.txt | 25 +++++++
> drivers/memory/Kconfig | 8 +++
> drivers/memory/Makefile | 1 +
> drivers/memory/da8xx-ddrctl.c | 77 +++++++++++++++++++
> 4 files changed, 111 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
> create mode 100644 drivers/memory/da8xx-ddrctl.c
>
> diff --git
> a/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
> b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
> new file mode 100644
> index 0000000..e340404
> --- /dev/null
> +++
> b/Documentation/devicetree/bindings/memory-controllers/ti-da8xx-ddrctl.txt
> @@ -0,0 +1,25 @@
> +* Device tree bindings for Texas Instruments da8xx DDR2/mDDR memory
> controller
> +
> +The DDR2/mDDR memory controller present on Texas Instruments da8xx SoCs
> memory
> +maps a set of registers which allow to tweak the controller's behavior.
> +
> +Documentation:
> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
> +
> +Required properties:
> +
> +- compatible: "ti,da850-ddrctl"

Don't you need a reg property ?

> +Optional properties:
> +
> +- ti,pr-old-count: Priority raise old counter. Specifies the number of
> + memory transfers after which the DDR2/mDDR memory
> + controller will elevate the priority of the oldest
> + command in the command FIFO. Must be between 0-255.

Isn't this a system configuration more than a hardware description ?

> +Example for da850 shown below.
> +
> +ddrctl {
> + compatible = "ti,da850-ddrctl";
> + ti,pr-old-count = <0x20>;
> +};
> diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
> index 4b4c0c3..ec80e35 100644
> --- a/drivers/memory/Kconfig
> +++ b/drivers/memory/Kconfig
> @@ -134,6 +134,14 @@ config MTK_SMI
> mainly help enable/disable iommu and control the power domain and
> clocks for each local arbiter.
>
> +config DA8XX_DDRCTL
> + bool "Texas Instruments da8xx DDR2/mDDR driver"
> + depends on ARCH_DAVINCI_DA8XX
> + help
> + This driver is for the DDR2/mDDR Memory Controller present on
> + Texas Instruments da8xx SoCs. It's used to tweak various memory
> + controller configuration options.
> +
> source "drivers/memory/samsung/Kconfig"
> source "drivers/memory/tegra/Kconfig"
>
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index b20ae38..e88097fb 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
> obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
> obj-$(CONFIG_JZ4780_NEMC) += jz4780-nemc.o
> obj-$(CONFIG_MTK_SMI) += mtk-smi.o
> +obj-$(CONFIG_DA8XX_DDRCTL) += da8xx-ddrctl.o
>
> obj-$(CONFIG_SAMSUNG_MC) += samsung/
> obj-$(CONFIG_TEGRA_MC) += tegra/
> diff --git a/drivers/memory/da8xx-ddrctl.c b/drivers/memory/da8xx-ddrctl.c
> new file mode 100644
> index 0000000..dcd0a61
> --- /dev/null
> +++ b/drivers/memory/da8xx-ddrctl.c
> @@ -0,0 +1,77 @@
> +/*
> + * TI da8xx DDR2/mDDR controller driver
> + *
> + * Copyright (C) 2016 BayLibre SAS
> + *
> + * Author:
> + * Bartosz Golaszewski <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +
> +#define DA8XX_DDR_CTL_BASE 0xB0000000
> +#define DA8XX_PBBPR_OFFSET 0x00000020
> +#define DA8XX_PBBPR_REG(p) ((p) + DA8XX_PBBPR_OFFSET)
> +
> +#define DA8XX_PBBPR_MAX 0xff
> +
> +static void da8xx_ddrctl_set_pbbpr(void __iomem *ddrctl, struct device
> *dev) +{
> + struct device_node *node = dev->of_node;
> + u32 pr_old_count;
> + int ret;
> +
> + ret = of_property_read_u32(node, "ti,pr-old-count", &pr_old_count);
> + if (ret)
> + return;
> +
> + if (pr_old_count > DA8XX_PBBPR_MAX) {
> + dev_warn(dev, "priority raise old counter value too high\n");
> + return;
> + }
> +
> + __raw_writel(pr_old_count, DA8XX_PBBPR_REG(ddrctl));
> +}
> +
> +static int da8xx_ddrctl_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + void __iomem *ddrctl;
> +
> + ddrctl = ioremap(DA8XX_DDR_CTL_BASE, SZ_256);
> + if (!ddrctl) {
> + dev_err(dev, "unable to map memory controller registers\n");
> + return -EIO;
> + }
> +
> + da8xx_ddrctl_set_pbbpr(ddrctl, dev);
> +
> + iounmap(ddrctl);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id da8xx_ddrctl_of_match[] = {
> + { .compatible = "ti,da850-ddrctl", },
> + { },
> +};
> +
> +static struct platform_driver da8xx_ddrctl_driver = {
> + .probe = da8xx_ddrctl_probe,
> + .driver = {
> + .name = "da8xx-ddrctl",
> + .of_match_table = da8xx_ddrctl_of_match,
> + },
> +};
> +module_platform_driver(da8xx_ddrctl_driver);
> +
> +MODULE_AUTHOR("Bartosz Golaszewski <[email protected]>");
> +MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
> +MODULE_LICENSE("GPL v2");

--
Regards,

Laurent Pinchart

2016-10-18 20:50:04

[permalink] [raw]

Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

Hi Bartosz,

Thank you for the patch.

On Monday 17 Oct 2016 18:30:49 Bartosz Golaszewski wrote:
> Create the driver for the da8xx System Configuration and implement
> support for writing to the three Master Priority registers.
>
> Signed-off-by: Bartosz Golaszewski <[email protected]>
> ---
> .../devicetree/bindings/bus/ti,da850-syscfg.txt | 63 +++++++
> drivers/bus/Kconfig | 8 +
> drivers/bus/Makefile | 2 +
> drivers/bus/da8xx-syscfg.c | 206 ++++++++++++++++++
> 4 files changed, 279 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt create mode
> 100644 drivers/bus/da8xx-syscfg.c
>
> diff --git a/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
> b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt new file mode
> 100644
> index 0000000..07e5c38
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
> @@ -0,0 +1,63 @@
> +* Device tree bindings for Texas Instruments da8xx system configuration
> driver
> +
> +The system configuration (SYSCFG) module is a system-level module
> containing
> +status and top level control logic required by the device. The system
> +configuration module consists of a set of memory-mapped status and control
> +registers, accessible by the CPU, supporting all of the following system
> +features, and miscellaneous functions and operations.
> +
> +Documentation:
> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
> +
> +Required properties:
> +
> +- compatible: "ti,da850-syscfg"

Don't you need a reg property ?

> +Optional properties:
> +
> +The below properties are used to specify the priority of master
> peripherals.
> +They must be between 0-7 where 0 is the highest priority and 7 is the
> lowest.
> +
> +- ti,pri-arm-i: ARM_I port priority.
> +
> +- ti,pri-arm-d: ARM_D port priority.
> +
> +- ti,pri-upp: uPP port priority.
> +
> +- ti,pri-sata: SATA port priority.
> +
> +- ti,pri-pru0: PRU0 port priority.
> +
> +- ti,pri-pru1: PRU1 port priority.
> +
> +- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
> +
> +- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
> +
> +- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
> +
> +- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
> +
> +- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
> +
> +- ti,pri-emac: EMAC port priority.
> +
> +- ti,pri-usb0cfg: USB0 CFG port priority.
> +
> +- ti,pri-usb0cdma: USB0 CDMA port priority.
> +
> +- ti,pri-uhpi: HPI port priority.
> +
> +- ti,pri-usb1: USB1 port priority.
> +
> +- ti,pri-lcdc: LCDC port priority.

I'm afraid this looks more like system configuration than hardware description
to me.

There was a BoF session about how to support this kind of performance knobs at
ELCE last week: https://openiotelceurope2016.sched.org/event/7rss/bof-linux-device-performance-framework-michael-turquette-baylibre :-)

> +If any of the above properties is absent, the default value will be used as
> +defined in the documentation.
> +
> +Example for da850-lcdk is shown below.
> +
> +mstpri {
> + compatible = "ti,da850-mstpri";
> + ti,pri-lcdc = 0;
> +};
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index 5a2d47c..6276132 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -165,4 +165,12 @@ config VEXPRESS_CONFIG
> help
> Platform configuration infrastructure for the ARM Ltd.
> Versatile Express.
> +
> +config DA8XX_SYSCFG
> + bool "TI da8xx system configuration driver"
> + depends on ARCH_DAVINCI_DA8XX
> + help
> + Driver for Texas Instruments da8xx system configuration. Allows to
> + adjust various SoC configuration options.
> +
> endmenu
> diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
> index c6cfa6b..3cba66a 100644
> --- a/drivers/bus/Makefile
> +++ b/drivers/bus/Makefile
> @@ -21,3 +21,5 @@ obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
> obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o
> obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
> obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o
> +
> +obj-$(CONFIG_DA8XX_SYSCFG) += da8xx-syscfg.o
> diff --git a/drivers/bus/da8xx-syscfg.c b/drivers/bus/da8xx-syscfg.c
> new file mode 100644
> index 0000000..8a2cb4f
> --- /dev/null
> +++ b/drivers/bus/da8xx-syscfg.c
> @@ -0,0 +1,206 @@
> +/*
> + * TI da8xx System Configuration driver
> + *
> + * Copyright (C) 2016 BayLibre SAS
> + *
> + * Author:
> + * Bartosz Golaszewski <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +
> +#define DA8XX_IO_PHYS 0x01c00000ul
> +#define DA8XX_SYSCFG0_BASE (DA8XX_IO_PHYS + 0x14000)
> +
> +#define DA8XX_MSTPRI0_REG 0x110
> +#define DA8XX_MSTPRI1_REG 0x114
> +#define DA8XX_MSTPRI2_REG 0x118
> +
> +#define DA8XX_MSTPRI_MAX 7
> +
> +struct da8xx_mstpri_descr {
> + const char *property;
> + int reg;
> + int shift;
> + int mask;
> +};
> +
> +static const struct da8xx_mstpri_descr priorities[] = {
> + {
> + .property = "ti,pri-arm-i",
> + .reg = DA8XX_MSTPRI0_REG,
> + .shift = 0,
> + .mask = 0xfffffff0,
> + },
> + {
> + .property = "ti,pri-arm-d",
> + .reg = DA8XX_MSTPRI0_REG,
> + .shift = 4,
> + .mask = 0xffffff0f,
> + },
> + {
> + .property = "ti,pri-upp",
> + .reg = DA8XX_MSTPRI0_REG,
> + .shift = 16,
> + .mask = 0xfff0ffff,
> + },
> + {
> + .property = "ti,pri-sata",
> + .reg = DA8XX_MSTPRI0_REG,
> + .shift = 20,
> + .mask = 0xff0fffff,
> + },
> + {
> + .property = "ti,pri-pru0",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 0,
> + .mask = 0xfffffff0,
> + },
> + {
> + .property = "ti,pri-pru1",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 4,
> + .mask = 0xffffff0f,
> + },
> + {
> + .property = "ti,pri-edma30tc0",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 8,
> + .mask = 0xfffff0ff,
> + },
> + {
> + .property = "ti,pri-edma30tc1",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 12,
> + .mask = 0xffff0fff,
> + },
> + {
> + .property = "ti,pri-edma31tc0",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 16,
> + .mask = 0xfff0ffff,
> + },
> + {
> + .property = "ti,pri-vpif-dma-0",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 24,
> + .mask = 0xf0ffffff,
> + },
> + {
> + .property = "ti,pri-vpif-dma-1",
> + .reg = DA8XX_MSTPRI1_REG,
> + .shift = 28,
> + .mask = 0x0fffffff,
> + },
> + {
> + .property = "ti,pri-emac",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 0,
> + .mask = 0xfffffff0,
> + },
> + {
> + .property = "ti,pri-usb0cfg",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 8,
> + .mask = 0xfffff0ff,
> + },
> + {
> + .property = "ti,pri-usb0cdma",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 12,
> + .mask = 0xffff0fff,
> + },
> + {
> + .property = "ti,pri-uhpi",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 20,
> + .mask = 0xff0fffff,
> + },
> + {
> + .property = "ti,pri-usb1",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 24,
> + .mask = 0xf0ffffff,
> + },
> + {
> + .property = "ti,pri-lcdc",
> + .reg = DA8XX_MSTPRI2_REG,
> + .shift = 28,
> + .mask = 0x0fffffff,
> + },
> +};
> +
> +static void da8xx_syscfg_set_mstpri(void __iomem *syscfg0, struct device
> *dev) +{
> + const struct da8xx_mstpri_descr *pri_descr;
> + struct device_node *node = dev->of_node;
> + void __iomem *mstpri;
> + u32 old_pri, new_pri;
> + int ret, i;
> +
> + for (i = 0; i < ARRAY_SIZE(priorities); i++) {
> + pri_descr = &priorities[i];
> +
> + ret = of_property_read_u32(node, pri_descr->property,
&new_pri);
> + if (ret)
> + continue;
> +
> + if (new_pri > DA8XX_MSTPRI_MAX) {
> + dev_warn(dev,
> + "omitting property '%s' - value too high\n",
> + pri_descr->property);
> + continue;
> + }
> +
> + mstpri = syscfg0 + pri_descr->reg;
> + old_pri = __raw_readl(mstpri);
> + old_pri &= pri_descr->mask;
> + new_pri <<= pri_descr->shift;
> + new_pri |= old_pri;
> +
> + __raw_writel(new_pri, mstpri);
> + }
> +}
> +
> +static int da8xx_syscfg_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + void __iomem *syscfg0;
> +
> + syscfg0 = ioremap(DA8XX_SYSCFG0_BASE, SZ_4K);
> + if (!syscfg0) {
> + dev_err(dev, "unable to map syscfg0\n");
> + return -EIO;
> + }
> +
> + da8xx_syscfg_set_mstpri(syscfg0, dev);
> +
> + iounmap(syscfg0);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id da8xx_syscfg_of_match[] = {
> + { .compatible = "ti,da850-syscfg", },
> + { },
> +};
> +
> +static struct platform_driver da8xx_syscfg_driver = {
> + .probe = da8xx_syscfg_probe,
> + .driver = {
> + .name = "da8xx-syscfg",
> + .of_match_table = da8xx_syscfg_of_match,
> + },
> +};
> +module_platform_driver(da8xx_syscfg_driver);
> +
> +MODULE_AUTHOR("Bartosz Golaszewski <[email protected]>");
> +MODULE_DESCRIPTION("TI da8xx System Configuration driver");
> +MODULE_LICENSE("GPL v2");

--
Regards,

Laurent Pinchart

2016-10-19 09:06:21

[permalink] [raw]

Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

Hi Bartosz,

On Wednesday 19 Oct 2016 10:26:57 Bartosz Golaszewski wrote:
> 2016-10-18 22:49 GMT+02:00 Laurent Pinchart:
> > On Monday 17 Oct 2016 18:30:49 Bartosz Golaszewski wrote:
> >> Create the driver for the da8xx System Configuration and implement
> >> support for writing to the three Master Priority registers.
> >>
> >> Signed-off-by: Bartosz Golaszewski <[email protected]>
>
> [snip]
>
> >> +
> >> +Documentation:
> >> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
> >> +
> >> +Required properties:
> >> +
> >> +- compatible: "ti,da850-syscfg"
> >
> > Don't you need a reg property ?
>
> Yes, Kevin already pointed that out. I'll add it in v2. Same for [1/3].
>
> >> +Optional properties:
> >> +
> >> +The below properties are used to specify the priority of master
> >> peripherals.
> >> +They must be between 0-7 where 0 is the highest priority and 7 is the
> >> lowest.
> >> +
> >> +- ti,pri-arm-i: ARM_I port priority.
> >> +
> >> +- ti,pri-arm-d: ARM_D port priority.
> >> +
> >> +- ti,pri-upp: uPP port priority.
> >> +
> >> +- ti,pri-sata: SATA port priority.
> >> +
> >> +- ti,pri-pru0: PRU0 port priority.
> >> +
> >> +- ti,pri-pru1: PRU1 port priority.
> >> +
> >> +- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
> >> +
> >> +- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
> >> +
> >> +- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
> >> +
> >> +- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
> >> +
> >> +- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
> >> +
> >> +- ti,pri-emac: EMAC port priority.
> >> +
> >> +- ti,pri-usb0cfg: USB0 CFG port priority.
> >> +
> >> +- ti,pri-usb0cdma: USB0 CDMA port priority.
> >> +
> >> +- ti,pri-uhpi: HPI port priority.
> >> +
> >> +- ti,pri-usb1: USB1 port priority.
> >> +
> >> +- ti,pri-lcdc: LCDC port priority.
> >
> > I'm afraid this looks more like system configuration than hardware
> > description to me.
>
> While you're certainly right, this approach is already implemented in
> several other memory and bus drivers and it was also suggested by
> Sekhar in one of the tilcdc rev1 threads. There's also no real
> alternative that I know of.

The fact that other drivers get it wrong is no excuse for copying them :-)

> > There was a BoF session about how to support this kind of performance
> > knobs at ELCE last week:
> > https://openiotelceurope2016.sched.org/event/7rss/bof-linux-device-perfor
> > mance-framework-michael-turquette-baylibre :-)
>
> I know, I was there. ;)

That's why I mentioned it :-)

> Unfortunately it was just a discussion about potential approaches -
> there's no code yet.

Patches are welcome ;-)

--
Regards,

Laurent Pinchart

2016-10-19 15:42:47

[permalink] [raw]

Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

2016-10-18 22:49 GMT+02:00 Laurent Pinchart <[email protected]>:
> Hi Bartosz,
>
> Thank you for the patch.
>
> On Monday 17 Oct 2016 18:30:49 Bartosz Golaszewski wrote:
>> Create the driver for the da8xx System Configuration and implement
>> support for writing to the three Master Priority registers.
>>
>> Signed-off-by: Bartosz Golaszewski <[email protected]>

[snip]

>> +
>> +Documentation:
>> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
>> +
>> +Required properties:
>> +
>> +- compatible: "ti,da850-syscfg"
>
> Don't you need a reg property ?
>

Yes, Kevin already pointed that out. I'll add it in v2. Same for [1/3].

>> +Optional properties:
>> +
>> +The below properties are used to specify the priority of master
>> peripherals.
>> +They must be between 0-7 where 0 is the highest priority and 7 is the
>> lowest.
>> +
>> +- ti,pri-arm-i: ARM_I port priority.
>> +
>> +- ti,pri-arm-d: ARM_D port priority.
>> +
>> +- ti,pri-upp: uPP port priority.
>> +
>> +- ti,pri-sata: SATA port priority.
>> +
>> +- ti,pri-pru0: PRU0 port priority.
>> +
>> +- ti,pri-pru1: PRU1 port priority.
>> +
>> +- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
>> +
>> +- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
>> +
>> +- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
>> +
>> +- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
>> +
>> +- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
>> +
>> +- ti,pri-emac: EMAC port priority.
>> +
>> +- ti,pri-usb0cfg: USB0 CFG port priority.
>> +
>> +- ti,pri-usb0cdma: USB0 CDMA port priority.
>> +
>> +- ti,pri-uhpi: HPI port priority.
>> +
>> +- ti,pri-usb1: USB1 port priority.
>> +
>> +- ti,pri-lcdc: LCDC port priority.
>
> I'm afraid this looks more like system configuration than hardware description
> to me.
>

While you're certainly right, this approach is already implemented in
several other memory and bus drivers and it was also suggested by
Sekhar in one of the tilcdc rev1 threads. There's also no real
alternative that I know of.

> There was a BoF session about how to support this kind of performance knobs at
> ELCE last week: https://openiotelceurope2016.sched.org/event/7rss/bof-linux-device-performance-framework-michael-turquette-baylibre :-)
>

I know, I was there. ;)

Unfortunately it was just a discussion about potential approaches -
there's no code yet.

Thanks,
Bartosz

2016-10-20 16:57:57

[permalink] [raw]

Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

+Arnd, Olof

Laurent Pinchart <[email protected]> writes:

> Hi Bartosz,
>
> On Wednesday 19 Oct 2016 10:26:57 Bartosz Golaszewski wrote:
>> 2016-10-18 22:49 GMT+02:00 Laurent Pinchart:
>> > On Monday 17 Oct 2016 18:30:49 Bartosz Golaszewski wrote:
>> >> Create the driver for the da8xx System Configuration and implement
>> >> support for writing to the three Master Priority registers.
>> >>
>> >> Signed-off-by: Bartosz Golaszewski <[email protected]>
>>
>> [snip]
>>
>> >> +
>> >> +Documentation:
>> >> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
>> >> +
>> >> +Required properties:
>> >> +
>> >> +- compatible: "ti,da850-syscfg"
>> >
>> > Don't you need a reg property ?
>>
>> Yes, Kevin already pointed that out. I'll add it in v2. Same for [1/3].
>>
>> >> +Optional properties:
>> >> +
>> >> +The below properties are used to specify the priority of master
>> >> peripherals.
>> >> +They must be between 0-7 where 0 is the highest priority and 7 is the
>> >> lowest.
>> >> +
>> >> +- ti,pri-arm-i: ARM_I port priority.
>> >> +
>> >> +- ti,pri-arm-d: ARM_D port priority.
>> >> +
>> >> +- ti,pri-upp: uPP port priority.
>> >> +
>> >> +- ti,pri-sata: SATA port priority.
>> >> +
>> >> +- ti,pri-pru0: PRU0 port priority.
>> >> +
>> >> +- ti,pri-pru1: PRU1 port priority.
>> >> +
>> >> +- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
>> >> +
>> >> +- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
>> >> +
>> >> +- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
>> >> +
>> >> +- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
>> >> +
>> >> +- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
>> >> +
>> >> +- ti,pri-emac: EMAC port priority.
>> >> +
>> >> +- ti,pri-usb0cfg: USB0 CFG port priority.
>> >> +
>> >> +- ti,pri-usb0cdma: USB0 CDMA port priority.
>> >> +
>> >> +- ti,pri-uhpi: HPI port priority.
>> >> +
>> >> +- ti,pri-usb1: USB1 port priority.
>> >> +
>> >> +- ti,pri-lcdc: LCDC port priority.
>> >
>> > I'm afraid this looks more like system configuration than hardware
>> > description to me.
>>
>> While you're certainly right, this approach is already implemented in
>> several other memory and bus drivers and it was also suggested by
>> Sekhar in one of the tilcdc rev1 threads. There's also no real
>> alternative that I know of.
>
> The fact that other drivers get it wrong is no excuse for copying them :-)

What exactly is "wrong" with the way other drivers are doing it?

I'm sure there may be other ideas, and possibly some better ones, but
that doesn't make it wrong, and doesn't change he fact that the kernel
has existing drivers SoC-bus-specific system performance knobs like
this.

>> > There was a BoF session about how to support this kind of performance
>> > knobs at ELCE last week:
>> > https://openiotelceurope2016.sched.org/event/7rss/bof-linux-device-perfor
>> > mance-framework-michael-turquette-baylibre :-)
>>
>> Unfortunately it was just a discussion about potential approaches -
>> there's no code yet.
>
> Patches are welcome ;-)

Any generic perf framework will have to build on the HW-specifics of
individual busses, so IMO, the lack of a generic performance
framework/knobs should not be a reason to block the inclusion of any
bus-specific knobs.

I guess this ultimately would go though arm-soc, so I've added Arnd &
Olof to the thread.

Kevin

2016-10-20 18:05:57

[permalink] [raw]

Subject: Re: [PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

Hi Kevin,

On Thursday 20 Oct 2016 09:57:51 Kevin Hilman wrote:
> Laurent Pinchart <[email protected]> writes:
> > On Wednesday 19 Oct 2016 10:26:57 Bartosz Golaszewski wrote:
> >> 2016-10-18 22:49 GMT+02:00 Laurent Pinchart:
> >>> On Monday 17 Oct 2016 18:30:49 Bartosz Golaszewski wrote:
> >>>> Create the driver for the da8xx System Configuration and implement
> >>>> support for writing to the three Master Priority registers.
> >>>>
> >>>> Signed-off-by: Bartosz Golaszewski <[email protected]>
> >>
> >> [snip]
> >>
> >>>> +
> >>>> +Documentation:
> >>>> +OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
> >>>> +
> >>>> +Required properties:
> >>>> +
> >>>> +- compatible: "ti,da850-syscfg"
> >>>
> >>> Don't you need a reg property ?
> >>
> >> Yes, Kevin already pointed that out. I'll add it in v2. Same for [1/3].
> >>
> >>>> +Optional properties:
> >>>> +
> >>>> +The below properties are used to specify the priority of master
> >>>> peripherals.
> >>>> +They must be between 0-7 where 0 is the highest priority and 7 is the
> >>>> lowest.
> >>>> +
> >>>> +- ti,pri-arm-i: ARM_I port priority.
> >>>> +
> >>>> +- ti,pri-arm-d: ARM_D port priority.
> >>>> +
> >>>> +- ti,pri-upp: uPP port priority.
> >>>> +
> >>>> +- ti,pri-sata: SATA port priority.
> >>>> +
> >>>> +- ti,pri-pru0: PRU0 port priority.
> >>>> +
> >>>> +- ti,pri-pru1: PRU1 port priority.
> >>>> +
> >>>> +- ti,pri-edma30tc0: EDMA3_0_TC0 port priority.
> >>>> +
> >>>> +- ti,pri-edma30tc1: EDMA3_0_TC1 port priority.
> >>>> +
> >>>> +- ti,pri-edma31tc0: EDMA3_1_TC0 port priority.
> >>>> +
> >>>> +- ti,pri-vpif-dma-0: VPIF DMA0 port priority.
> >>>> +
> >>>> +- ti,pri-vpif-dma-1: VPIF DMA1 port priority.
> >>>> +
> >>>> +- ti,pri-emac: EMAC port priority.
> >>>> +
> >>>> +- ti,pri-usb0cfg: USB0 CFG port priority.
> >>>> +
> >>>> +- ti,pri-usb0cdma: USB0 CDMA port priority.
> >>>> +
> >>>> +- ti,pri-uhpi: HPI port priority.
> >>>> +
> >>>> +- ti,pri-usb1: USB1 port priority.
> >>>> +
> >>>> +- ti,pri-lcdc: LCDC port priority.
> >>>
> >>> I'm afraid this looks more like system configuration than hardware
> >>> description to me.
> >>
> >> While you're certainly right, this approach is already implemented in
> >> several other memory and bus drivers and it was also suggested by
> >> Sekhar in one of the tilcdc rev1 threads. There's also no real
> >> alternative that I know of.
> >
> > The fact that other drivers get it wrong is no excuse for copying them :-)
>
> What exactly is "wrong" with the way other drivers are doing it?
>
> I'm sure there may be other ideas, and possibly some better ones, but
> that doesn't make it wrong, and doesn't change he fact that the kernel
> has existing drivers SoC-bus-specific system performance knobs like
> this.

It's not the drivers I'm concerned about, but the DT bindings. The proposed DT
binding contains a large number of properties that don't describe the hardware
but contain configuration data. If they're accepted you'll have to carry them
forward forever, while they should be controlled in a more flexible way.

> >>> There was a BoF session about how to support this kind of performance
> >>> knobs at ELCE last week:
> >>> https://openiotelceurope2016.sched.org/event/7rss/bof-linux-device-perf
> >>> ormance-framework-michael-turquette-baylibre :-)
> >>
> >> Unfortunately it was just a discussion about potential approaches -
> >> there's no code yet.
> >
> > Patches are welcome ;-)
>
> Any generic perf framework will have to build on the HW-specifics of
> individual busses, so IMO, the lack of a generic performance
> framework/knobs should not be a reason to block the inclusion of any
> bus-specific knobs.
>
> I guess this ultimately would go though arm-soc, so I've added Arnd &
> Olof to the thread.

--
Regards,

Laurent Pinchart

2016-10-20 19:39:40