| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <5513D450.2080609@linaro.org>
Date: Thu, 26 Mar 2015 10:41:36 +0100
From: Daniel Lezcano <daniel.lezcano@...aro.org>
To: Holger Dengler <dengler@...utronix.de>,
linux-kernel@...r.kernel.org
CC: Peter Mahler <mahler@...ug.com>, Juergen Bubeck <bubeck@...ug.com>,
Benedikt Spranger <b.spranger@...utronix.de>,
Thomas Gleixner <tglx@...utronix.de>,
John Stultz <john.stultz@...aro.org>
Subject: Re: [PATCH 10/11] clocksource: flexcard: Add basic timestamp counter
support
Hi Holger,
[Cc'ed John Stultz]
On 03/25/2015 10:51 AM, Holger Dengler wrote:
> From: Benedikt Spranger <b.spranger@...utronix.de>
>
> The Eberspaecher Flexcard PMC II offers a Flexray network synchronized
> counter with a selectable resolution of 1us, 100ns or 10ns. Add basic
> support for the timestamp counter with 1us resolution, which is the
> standard Flexray bus resolution.
>
> Signed-off-by: Holger Dengler <dengler@...utronix.de>
> Signed-off-by: Benedikt Spranger <b.spranger@...utronix.de>
> cc: Daniel Lezcano <daniel.lezcano@...aro.org>
> cc: Thomas Gleixner <tglx@...utronix.de>
> ---
> drivers/clocksource/Kconfig | 11 ++
> drivers/clocksource/Makefile | 1 +
> drivers/clocksource/flexcard-time.c | 235 ++++++++++++++++++++++++++++++++++++
> include/linux/mfd/flexcard.h | 6 +
> 4 files changed, 253 insertions(+)
> create mode 100644 drivers/clocksource/flexcard-time.c
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index 68161f7..a6b9308 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -250,4 +250,15 @@ config CLKSRC_PXA
> help
> This enables OST0 support available on PXA and SA-11x0
> platforms.
> +
> +config CLKSRC_FLEXCARD
> + tristate "Support for Flexcard clock function"
Why do you need this to be a module ?
The Kconfig policy is to have it selected by the arch Kconfig.
It should be like:
config CLKSRC_FLEXCARD
bool
select CLKSRC_MMIO
and then the Kconfig for MFD_FLEXCARD selects CLKSRC_FLEXCARD.
> + depends on MFD_FLEXCARD
> + select CLKSRC_MMIO
> + help
> + This is the clocksource function driver for the
> + Eberspaecher Flexcard PMC II carrier board. The
> + Flexcard provide a Flexray synchronized counter
> + configurable at 1, 10 or 100MHz.
> +
> endmenu
> diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
> index 752d5c7..8bbc657 100644
> --- a/drivers/clocksource/Makefile
> +++ b/drivers/clocksource/Makefile
> @@ -51,3 +51,4 @@ obj-$(CONFIG_ARCH_INTEGRATOR_AP) += timer-integrator-ap.o
> obj-$(CONFIG_CLKSRC_VERSATILE) += versatile.o
> obj-$(CONFIG_CLKSRC_MIPS_GIC) += mips-gic-timer.o
> obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o
> +obj-$(CONFIG_CLKSRC_FLEXCARD) += flexcard-time.o
> diff --git a/drivers/clocksource/flexcard-time.c b/drivers/clocksource/flexcard-time.c
> new file mode 100644
> index 0000000..f2efb53
> --- /dev/null
> +++ b/drivers/clocksource/flexcard-time.c
> @@ -0,0 +1,235 @@
> +/*
> + * Eberspaecher Flexcard PMC II - clocksource driver
> + *
> + * Copyright (c) 2014,2015 Linutronix GmbH
> + * Author: Holger Dengler
> + * Benedikt Spranger
> + *
> + * 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/fs.h>
> +#include <linux/miscdevice.h>
> +#include <linux/platform_device.h>
> +#include <linux/posix-clock.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/flexcard.h>
> +
> +#define MAX_CLOCKS 16
> +#define CLKSEL_OFF 0x10
> +
> +static dev_t flexcard_clk_devt;
> +static struct class *flexcard_clk_class;
> +
> +struct flexcard_clk {
> + struct posix_clock clock;
> + dev_t devid;
> + struct device *dev;
> + void __iomem *ts64;
> + void __iomem *reset;
> +};
> +
> +static int flexcard_clk_getres(struct posix_clock *pc, struct timespec *tp)
> +{
> + tp->tv_sec = 0;
> + tp->tv_nsec = 1000;
> +
> + return 0;
> +}
> +
> +static int flexcard_clk_gettime(struct posix_clock *pc, struct timespec *tp)
> +{
> + struct flexcard_clk *clk = container_of(pc, struct flexcard_clk, clock);
> + u64 now;
> + u32 upper, rem;
> +
> +retry:
> + upper = readl(clk->ts64);
> + now = ((u64) upper << 32) | readl(clk->ts64 + 4);
> + if (upper != readl(clk->ts64))
> + goto retry;
> +
> + tp->tv_sec = div_u64_rem(now, clk->desc.freq, &rem);
> + tp->tv_nsec = rem * 1000;
> +
> + return 0;
> +}
> +
> +static int flexcard_clk_settime(struct posix_clock *pc,
> + const struct timespec *tp)
> +{
> + struct flexcard_clk *clk = container_of(pc, struct flexcard_clk, clock);
> +
> + /* The FlexCard clock could only be reset to 0 and not set */
> + if (tp->tv_sec || tp->tv_nsec)
> + return -EINVAL;
> +
> + writel(FLEXCARD_RST_TS, clk->reset);
> +
> + return 0;
> +}
> +
> +static struct posix_clock_operations flexcard_clk_ops = {
> + .owner = THIS_MODULE,
> + .clock_getres = flexcard_clk_getres,
> + .clock_gettime = flexcard_clk_gettime,
> + .clock_settime = flexcard_clk_settime,
> +};
> +
> +static int flexcard_clksrc_iomap(struct platform_device *pdev)
> +{
> + struct flexcard_clk *clk = platform_get_drvdata(pdev);
> + struct resource *res;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENXIO;
> +
> + clk->ts64 = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> + if (!clk->ts64)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (!res)
> + return -ENXIO;
> +
> + clk->reset = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> + if (!clk->reset)
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +static int flexcard_clksrc_probe(struct platform_device *pdev)
> +{
> + const struct mfd_cell *cell;
> + struct flexcard_clk *clk;
> + int major, ret;
> +
> + cell = mfd_get_cell(pdev);
> + if (!cell)
> + return -ENODEV;
> +
> + if (cell->id >= MAX_CLOCKS) {
> + dev_err(&pdev->dev, "all flexcard posix clocks in use\n");
> + return -EBUSY;
> + }
> +
> + clk = devm_kzalloc(&pdev->dev, sizeof(*clk), GFP_KERNEL);
> + if (!clk)
> + return -ENOMEM;
> +
> + major = MAJOR(flexcard_clk_devt);
> + platform_set_drvdata(pdev, clk);
> +
> + ret = flexcard_clksrc_iomap(pdev);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to map resources: %d\n", ret);
> + goto out;
> + }
> +
> + clk->devid = MKDEV(major, cell->id);
> + clk->clock.ops = flexcard_clk_ops;
> +
> + writel(FLEXCARD_CLK_1MHZ, clk->ts64 + CLKSEL_OFF);
> + writel(FLEXCARD_RST_TS, clk->reset);
> +
> + clk->dev = device_create(flexcard_clk_class, &pdev->dev, clk->devid,
> + clk, "flexcard_clk%d", cell->id);
> + if (IS_ERR(clk->dev)) {
> + ret = PTR_ERR(clk->dev);
> + goto out;
> + }
> +
> + ret = posix_clock_register(&clk->clock, clk->devid);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "failed to register flexcard posix clock: %d\n", ret);
> + goto out_destroy;
> + }
> +
> + dev_info(&pdev->dev, "flexcard posix clock %d registered", cell->id);
> +
> + return 0;
> +
> +out_destroy:
> + device_destroy(flexcard_clk_class, clk->devid);
> +out:
> + return ret;
> +}
> +
> +static int flexcard_clksrc_remove(struct platform_device *pdev)
> +{
> + struct flexcard_clk *clk = platform_get_drvdata(pdev);
> +
> + posix_clock_unregister(&clk->clock);
> + device_destroy(flexcard_clk_class, clk->devid);
> + platform_set_drvdata(pdev, NULL);
> +
> + return 0;
> +}
> +
> +static const struct platform_device_id flexcard_clksrc_id_table[] = {
> + { "flexcard-clksrc", 0 },
> + {},
> +};
> +MODULE_DEVICE_TABLE(platform, flexcard_clksrc_id_table);
> +
> +static struct platform_driver flexcard_clksrc_driver = {
> + .probe = flexcard_clksrc_probe,
> + .remove = flexcard_clksrc_remove,
> + .driver = {
> + .name = "flexcard-clksrc",
> + },
> + .id_table = flexcard_clksrc_id_table,
> +};
> +
> +static int __init flexcard_clksrc_init(void)
> +{
> + int ret;
> +
> + flexcard_clk_class = class_create(THIS_MODULE, "flexcard_clk");
> + if (IS_ERR(flexcard_clk_class)) {
> + pr_err("flexcard_clk: failed to allocate class\n");
> + return PTR_ERR(flexcard_clk_class);
> + }
> +
> + ret = alloc_chrdev_region(&flexcard_clk_devt, 0, MAX_CLOCKS,
> + "flexcard_clk");
> + if (ret < 0) {
> + pr_err("failed to allocate device region\n");
> + goto out;
> + }
> +
> + ret = platform_driver_register(&flexcard_clksrc_driver);
> + if (ret < 0)
> + goto out_unregister;
> +
> + return 0;
> +
> +out_unregister:
> + unregister_chrdev_region(flexcard_clk_devt, MAX_CLOCKS);
> +out:
> + class_destroy(flexcard_clk_class);
> +
> + return ret;
> +}
> +
> +static void __exit flexcard_clksrc_exit(void)
> +{
> + platform_driver_unregister(&flexcard_clksrc_driver);
> + unregister_chrdev_region(flexcard_clk_devt, MAX_CLOCKS);
> + class_destroy(flexcard_clk_class);
> +}
> +
> +MODULE_AUTHOR("Holger Dengler <dengler@...utronix.de>");
> +MODULE_AUTHOR("Benedikt Spranger <b.spranger@...utronix.de>");
> +MODULE_DESCRIPTION("Eberspaecher Flexcard PMC II clocksource driver");
> +MODULE_LICENSE("GPL v2");
> +
> +module_init(flexcard_clksrc_init);
> +module_exit(flexcard_clksrc_exit);
> diff --git a/include/linux/mfd/flexcard.h b/include/linux/mfd/flexcard.h
> index 964d78c..d7ecf3d 100644
> --- a/include/linux/mfd/flexcard.h
> +++ b/include/linux/mfd/flexcard.h
> @@ -19,8 +19,14 @@
> #define FLEXCARD_FR_OFFSET 0x4000
> #define FLEXCARD_FR_SIZE 0x2000
>
> +#define FLEXCARD_RST_TS 0x8000
> +
> #define FLEXCARD_MAX_NAME 16
>
> +#define FLEXCARD_CLK_1MHZ 0
> +#define FLEXCARD_CLK_10MHZ 1
> +#define FLEXCARD_CLK_100MHZ 2
> +
> struct flexcard_device {
> raw_spinlock_t irq_lock;
> struct pci_dev *pdev;
>
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists