diff mbox

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

Message ID 1476721850-454-3-git-send-email-bgolaszewski@baylibre.com (mailing list archive)
State New, archived
Headers show

Commit Message

Bartosz Golaszewski Oct. 17, 2016, 4:30 p.m. UTC
Create the driver for the da8xx System Configuration and implement
support for writing to the three Master Priority registers.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 .../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

Comments

Kevin Hilman Oct. 17, 2016, 4:57 p.m. UTC | #1
Bartosz Golaszewski <bgolaszewski@baylibre.com> 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 <bgolaszewski@baylibre.com>

[...]

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

The base addr should come from DT.

Kevin
Laurent Pinchart Oct. 18, 2016, 8:49 p.m. UTC | #2
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 <bgolaszewski@baylibre.com>
> ---
>  .../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 <bgolaszewski@baylibre.com.com>
> + *
> + * 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 <bgolaszewski@baylibre.com>");
> +MODULE_DESCRIPTION("TI da8xx System Configuration driver");
> +MODULE_LICENSE("GPL v2");
Bartosz Golaszewski Oct. 19, 2016, 8:26 a.m. UTC | #3
2016-10-18 22:49 GMT+02:00 Laurent Pinchart <laurent.pinchart@ideasonboard.com>:
> 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 <bgolaszewski@baylibre.com>

[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
Laurent Pinchart Oct. 19, 2016, 8:53 a.m. UTC | #4
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 <bgolaszewski@baylibre.com>
> 
> [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 ;-)
Kevin Hilman Oct. 20, 2016, 4:57 p.m. UTC | #5
+Arnd, Olof

Laurent Pinchart <laurent.pinchart@ideasonboard.com> 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 <bgolaszewski@baylibre.com>
>> 
>> [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
Laurent Pinchart Oct. 20, 2016, 6:05 p.m. UTC | #6
Hi Kevin,

On Thursday 20 Oct 2016 09:57:51 Kevin Hilman wrote:
> Laurent Pinchart <laurent.pinchart@ideasonboard.com> 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 <bgolaszewski@baylibre.com>
> >> 
> >> [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.
Kevin Hilman Oct. 20, 2016, 7:39 p.m. UTC | #7
Hi Laurent,

Laurent Pinchart <laurent.pinchart@ideasonboard.com> writes:

> On Thursday 20 Oct 2016 09:57:51 Kevin Hilman wrote:
>> Laurent Pinchart <laurent.pinchart@ideasonboard.com> 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 <bgolaszewski@baylibre.com>
>> >> 
>> >> [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.

I see, thanks for the clarification.

> The proposed DT binding contains a large number of properties that
> don't describe the hardware but contain configuration data.

I agree that there ought to be some more generic way for devices to
request performance constraints from their busses at runtime based on
their current operating critera, but unfortunately that doesn't exist
yet.

However, after our discussion on IRC, we'll respin this without the DT
bindings at all.  Next version will just use static configuration data
in the drivers/bus driver based on SoC compatible string, since for the
use-cases I'm aware of, the settings are boot-time only.

Thanks again for the review,

Kevin
Tomi Valkeinen Oct. 21, 2016, 9:25 a.m. UTC | #8
On 20/10/16 22:39, Kevin Hilman wrote:

> However, after our discussion on IRC, we'll respin this without the DT
> bindings at all.  Next version will just use static configuration data
> in the drivers/bus driver based on SoC compatible string, since for the
> use-cases I'm aware of, the settings are boot-time only.

If it's static boot time config, why not do it in the u-boot?

I'm fine either way, but this sounds like quite low level memory bus config.

 Tomi
Sekhar Nori Oct. 21, 2016, 9:53 a.m. UTC | #9
On Friday 21 October 2016 02:55 PM, Tomi Valkeinen wrote:
> On 20/10/16 22:39, Kevin Hilman wrote:
> 
>> However, after our discussion on IRC, we'll respin this without the DT
>> bindings at all.  Next version will just use static configuration data
>> in the drivers/bus driver based on SoC compatible string, since for the
>> use-cases I'm aware of, the settings are boot-time only.
> 
> If it's static boot time config, why not do it in the u-boot?

Hardware initialization dependencies with boot-loader are tough to track
and debug. The bootloader thats currently ships with the board may not
have these settings, for example. This forces everyone to update their
bootloader when shifting to mainline kernel.

Thanks,
Sekhar
Tomi Valkeinen Oct. 21, 2016, 9:56 a.m. UTC | #10
On 21/10/16 12:53, Sekhar Nori wrote:
> On Friday 21 October 2016 02:55 PM, Tomi Valkeinen wrote:
>> On 20/10/16 22:39, Kevin Hilman wrote:
>>
>>> However, after our discussion on IRC, we'll respin this without the DT
>>> bindings at all.  Next version will just use static configuration data
>>> in the drivers/bus driver based on SoC compatible string, since for the
>>> use-cases I'm aware of, the settings are boot-time only.
>>
>> If it's static boot time config, why not do it in the u-boot?
> 
> Hardware initialization dependencies with boot-loader are tough to track
> and debug. The bootloader thats currently ships with the board may not
> have these settings, for example. This forces everyone to update their
> bootloader when shifting to mainline kernel.

Yep, true... We need something similar for AM335x too. And perhaps for
other SoCs too (AM4 comes to my mind).

 Tomi
diff mbox

Patch

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 <bgolaszewski@baylibre.com.com>
+ *
+ * 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 <bgolaszewski@baylibre.com>");
+MODULE_DESCRIPTION("TI da8xx System Configuration driver");
+MODULE_LICENSE("GPL v2");