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: Benedikt Spranger <b.spran...@linutronix.de>
Signed-off-by: Holger Dengler <deng...@linutronix.de>
cc: Arnd Bergmann <a...@arndb.de>
cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/mfd/Kconfig | 1 +
drivers/misc/Kconfig | 9 ++
drivers/misc/Makefile | 1 +
drivers/misc/flexcard_posixclock.c | 240 +++++++++++++++++++++++++++++++++++++
4 files changed, 251 insertions(+)
create mode 100644 drivers/misc/flexcard_posixclock.c
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 580f521..490b435 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -304,6 +304,7 @@ config MFD_FLEXCARD
select MFD_CORE
select IRQ_DOMAIN
select FLEXCARD_MISC
+ select FLEXCARD_PCLOCK
depends on PCI
help
This is the core driver for the Eberspaecher Flexcard
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3f54b58..658a6df 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -772,6 +772,15 @@ config FLEXCARD_MISC
help
Misc driver for Flexcard PMC II.
+config FLEXCARD_PCLOCK
+ tristate "Flexcard posix clock Function driver"
+ depends on MFD_FLEXCARD
+ help
+ This is the posix clock function driver for the
+ Eberspaecher Flexcard PMC II carrier board. The
+ Flexcard provide a Flexray synchronized counter
+ configurable at 1, 10 or 100MHz.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 08a1729..df655bb 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
obj-$(CONFIG_CXL_BASE) += cxl/
obj-$(CONFIG_PANEL) += panel.o
obj-$(CONFIG_FLEXCARD_MISC) += flexcard_misc.o
+obj-$(CONFIG_FLEXCARD_PCLOCK) += flexcard_posixclock.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_bugs.o
diff --git a/drivers/misc/flexcard_posixclock.c
b/drivers/misc/flexcard_posixclock.c
new file mode 100644
index 0000000..146f0f3
--- /dev/null
+++ b/drivers/misc/flexcard_posixclock.c
@@ -0,0 +1,240 @@
+/*
+ * Eberspächer Flexcard PMC II - posix clock driver
+ *
+ * Copyright (c) 2014 - 2016, Linutronix GmbH
+ * Author: Benedikt Spranger <b.spran...@linutronix.de>
+ * Holger Dengler <deng...@linutronix.de>
+ *
+ * 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
+
+#define FLEXCARD_RST_TS 0x8000
+
+#define FLEXCARD_CLK_1MHZ 0
+
+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, 1000000, &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 posix 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_clk_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_clk_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: %d\n",
+ cell->id);
+ 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_clk_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_clock%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_clk_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_clk_id_table[] = {
+ { "flexcard-clock", 0 },
+ {},
+};
+MODULE_DEVICE_TABLE(platform, flexcard_clk_id_table);
+
+static struct platform_driver flexcard_clk_driver = {
+ .probe = flexcard_clk_probe,
+ .remove = flexcard_clk_remove,
+ .driver = {
+ .name = "flexcard-clock",
+ },
+ .id_table = flexcard_clk_id_table,
+};
+
+static int __init flexcard_clk_init(void)
+{
+ int ret;
+
+ flexcard_clk_class = class_create(THIS_MODULE, "flexcard_clock");
+ if (IS_ERR(flexcard_clk_class)) {
+ pr_err("flexcard_clock: failed to allocate class\n");
+ return PTR_ERR(flexcard_clk_class);
+ }
+
+ ret = alloc_chrdev_region(&flexcard_clk_devt, 0, MAX_CLOCKS,
+ "flexcard_clock");
+ if (ret < 0) {
+ pr_err("failed to allocate device region\n");
+ goto out;
+ }
+
+ ret = platform_driver_register(&flexcard_clk_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_clk_exit(void)
+{
+ platform_driver_unregister(&flexcard_clk_driver);
+ unregister_chrdev_region(flexcard_clk_devt, MAX_CLOCKS);
+ class_destroy(flexcard_clk_class);
+}
+
+module_init(flexcard_clk_init);
+module_exit(flexcard_clk_exit);
+
+MODULE_AUTHOR("Holger Dengler <deng...@linutronix.de>");
+MODULE_AUTHOR("Benedikt Spranger <b.spran...@linutronix.de>");
+MODULE_DESCRIPTION("Eberspaecher Flexcard PMC II posix clock driver");
+MODULE_LICENSE("GPL v2");
--
2.1.4
