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

From: Laurent Pinchart
Date: Tue Oct 18 2016 - 16:50:06 EST

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@xxxxxxxxxxxx>
> ---
> .../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@xxxxxxxxxxxxxxxx>
> + *
> + * 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@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("TI da8xx System Configuration driver");
> +MODULE_LICENSE("GPL v2");

--
Regards,

Laurent Pinchart