[PATCH 2/2] drivers: misc: add ripple counter driver
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Date: 2021-02-26 14:16:31
Also in:
linux-clk, lkml
Subsystem:
char and misc drivers, the rest · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Linus Torvalds
The only purpose of this driver is to serve as a consumer of the input clock, to prevent it from being disabled by clk_disable_unused(). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> --- drivers/misc/Kconfig | 7 +++++++ drivers/misc/Makefile | 1 + drivers/misc/ripple-ctr.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+) create mode 100644 drivers/misc/ripple-ctr.c
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index f532c59bb59b..44b0b6ce42df 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig@@ -445,6 +445,13 @@ config HISI_HIKEY_USB switching between the dual-role USB-C port and the USB-A host ports using only one USB controller. +config RIPPLE_CTR + tristate "Trivial ripple counter driver" + help + This provides a stub driver for a ripple counter, whose + only purpose is to request and enable the clock source + driving the counter. + 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 99b6f15a3c70..d560163068a9 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile@@ -56,3 +56,4 @@ obj-$(CONFIG_HABANA_AI) += habanalabs/ obj-$(CONFIG_UACCE) += uacce/ obj-$(CONFIG_XILINX_SDFEC) += xilinx_sdfec.o obj-$(CONFIG_HISI_HIKEY_USB) += hisi_hikey_usb.o +obj-$(CONFIG_RIPPLE_CTR) += ripple-ctr.o
diff --git a/drivers/misc/ripple-ctr.c b/drivers/misc/ripple-ctr.c
new file mode 100644
index 000000000000..f086eaf335df
--- /dev/null
+++ b/drivers/misc/ripple-ctr.c@@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +static int ripple_ctr_probe(struct platform_device *pdev) +{ + struct clk *clk; + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + return clk_prepare_enable(clk); +} + +static const struct of_device_id ripple_ctr_ids[] = { + { .compatible = "linux,ripple-counter", }, + { } +}; +MODULE_DEVICE_TABLE(of, ripple_ctr_ids); + +static struct platform_driver ripple_ctr_driver = { + .driver = { + .name = "ripple-counter", + .of_match_table = ripple_ctr_ids, + }, + .probe = ripple_ctr_probe, +}; +module_platform_driver(ripple_ctr_driver);
--
2.29.2