From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fGnNB-0007mR-RJ for barebox@lists.infradead.org; Thu, 10 May 2018 15:20:52 +0000 Received: by mail-wm0-x241.google.com with SMTP id y189-v6so5032961wmc.3 for ; Thu, 10 May 2018 08:20:38 -0700 (PDT) From: Nikita Yushchenko Date: Thu, 10 May 2018 18:20:18 +0300 Message-Id: <20180510152019.9607-1-nikita.yoush@cogentembedded.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH 1/2] clk: add clk-gpio driver To: Sascha Hauer Cc: Nikita Yushchenko , barebox@lists.infradead.org, Chris Healy This implements support for gpio-gate-clock device tree nodes, that define clocks that can be enabled or disabled via GPIO line. Signed-off-by: Nikita Yushchenko --- drivers/clk/Makefile | 2 +- drivers/clk/clk-gpio.c | 130 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 131 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/clk-gpio.c diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 55ac9535a..cd4026c94 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -1,7 +1,7 @@ obj-$(CONFIG_COMMON_CLK) += clk.o clk-fixed.o clk-divider.o clk-fixed-factor.o \ clk-mux.o clk-gate.o clk-composite.o \ clk-fractional-divider.o clk-conf.o \ - clk-gate-shared.o + clk-gate-shared.o clk-gpio.o obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o obj-$(CONFIG_ARCH_MVEBU) += mvebu/ diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c new file mode 100644 index 000000000..352c85dfe --- /dev/null +++ b/drivers/clk/clk-gpio.c @@ -0,0 +1,130 @@ +/* + * clk-gpio.c - clock that can be enabled and disabled via GPIO output + * Based on Linux clk support + * + * Copyright (c) 2018 Nikita Yushchenko + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ +#include +#include +#include +#include +#include +#include +#include + +struct clk_gpio { + struct clk clk; + const char *parent; + int gpio; +}; +#define to_clk_gpio(_clk) container_of(_clk, struct clk_gpio, clk) + +static int clk_gpio_enable(struct clk *clk) +{ + struct clk_gpio *clk_gpio = to_clk_gpio(clk); + + gpio_set_active(clk_gpio->gpio, true); + return 0; +} + +static void clk_gpio_disable(struct clk *clk) +{ + struct clk_gpio *clk_gpio = to_clk_gpio(clk); + + gpio_set_active(clk_gpio->gpio, false); +} + +static int clk_gpio_is_enabled(struct clk *clk) +{ + struct clk_gpio *clk_gpio = to_clk_gpio(clk); + + return gpio_is_active(clk_gpio->gpio); +} + +static struct clk_ops clk_gpio_ops = { + .set_rate = clk_parent_set_rate, + .round_rate = clk_parent_round_rate, + .enable = clk_gpio_enable, + .disable = clk_gpio_disable, + .is_enabled = clk_gpio_is_enabled, +}; + +static int of_gpio_clk_setup(struct device_node *node) +{ + struct clk_gpio *clk_gpio; + enum of_gpio_flags of_flags; + unsigned long flags; + int ret; + + clk_gpio = xzalloc(sizeof(*clk_gpio)); + if (!clk_gpio) + return -ENOMEM; + + clk_gpio->parent = of_clk_get_parent_name(node, 0); + if (!clk_gpio->parent) { + ret = -EINVAL; + goto no_parent; + } + + clk_gpio->clk.ops = &clk_gpio_ops; + clk_gpio->clk.parent_names = &clk_gpio->parent; + clk_gpio->clk.num_parents = 1; + + clk_gpio->clk.name = node->name; + of_property_read_string(node, "clock-output-names", + &clk_gpio->clk.name); + + ret = of_get_named_gpio_flags(node, "enable-gpios", 0, + &of_flags); + if (ret >= 0 && !gpio_is_valid(ret)) + ret = -EINVAL; + if (ret < 0) + goto no_gpio; + clk_gpio->gpio = ret; + + flags = GPIOF_OUT_INIT_ACTIVE; + if (of_flags & OF_GPIO_ACTIVE_LOW) + flags |= GPIOF_ACTIVE_LOW; + ret = gpio_request_one(clk_gpio->gpio, flags, clk_gpio->clk.name); + if (ret) + goto no_request; + + ret = clk_register(&clk_gpio->clk); + if (ret) + goto no_register; + + return of_clk_add_provider(node, of_clk_src_simple_get, &clk_gpio->clk); + +no_register: + gpio_free(clk_gpio->gpio); +no_request: +no_gpio: +no_parent: + free(clk_gpio); + return ret; +} + +/* Can't use OF_CLK_DECLARE due to need to run after GPIOcontrollers have + * registrered */ + +static const struct of_device_id clk_gpio_device_id[] = { + { .compatible = "gpio-gate-clock", .data = of_gpio_clk_setup, }, + {} +}; + +static int clk_gpio_init(void) +{ + return of_clk_init(NULL, clk_gpio_device_id); +} +coredevice_initcall(clk_gpio_init); -- 2.11.0 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox