From patchwork Wed Aug 28 10:15:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiko Stuebner X-Patchwork-Id: 13781056 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2022166312; Wed, 28 Aug 2024 10:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724840121; cv=none; b=g21dK5rktI/Hnn5g8UOFbR/bmik8sdrxXQqi1+cROkQnTdiynRLWaGjhCxd3iJXCQY9pwxqiuLsDTQslLDYmkJzbgEYYx/PfVo1TQ/gIu2czLbQHuT2GMo2Owrsl7L65I8jHgA5ztGGLGta0bweMUZvL+6QH7AREATZePVao1zM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724840121; c=relaxed/simple; bh=KoT6uOr7NzEkQNsaRZtbnbzPhUcTeLbMlSihvlNQo8w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZDBpEGndOHEV25kq4DG2QM2IBG3BQP8U9YDE9/U5o9g+xLjUPE1qiqoCOKr65GQtSl8mFcn+7hXVqO3yq4/1axWY+RFeQO6M34WGom3ygJEJwpr/N/NevbbwEtYdXpWf3MikVSvtvV/NU8LsBomtcrCcyLlVpxHyMxpMtFdnTfM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=DXz8Peaa; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="DXz8Peaa" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=2vEIhifhCgUZJb7JLEMEs6FgsfJuYynN2BlO+zQ+JIg=; b=DXz8PeaaBwK3stcuG4xOq3+jEa t0pc4wEGkwsDwLAKzV7lSJllRe57nMtdiCu8loAHut3ETib8zEGPT1VmUWmKSfuh06Es7v/cJIyJp aolH63EZ8Zx2GpGoYoZrYSkzExaejScFlPgJ2FN1/f0jDQU/RIfMHFXob36O9yz+n++b5hJZtDb0x 7wkpNlhiOAtSl2/3ZX1psHo9ou3cDlE4Be2q+5fpLb8i+hmxreufSrIs+iw8tNhO0QmS2ihSbOggv mnrXFDBHneFsq4xHenDLZGLg7IxZ2/lDnW/eD0Piy5DMsx1lbfVvVzWenqdE7UKtwdCZGHrWd3/bK TKAusGmw==; Received: from i5e8616cd.versanet.de ([94.134.22.205] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sjFht-0004M3-OU; Wed, 28 Aug 2024 12:15:17 +0200 From: Heiko Stuebner To: mturquette@baylibre.com, sboyd@kernel.org Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, linux-clk@vger.kernel.org, heiko@sntech.de, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: [PATCH v3 4/5] clk: clk-gpio: add driver for gated-fixed-clocks Date: Wed, 28 Aug 2024 12:15:02 +0200 Message-ID: <20240828101503.1478491-5-heiko@sntech.de> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240828101503.1478491-1-heiko@sntech.de> References: <20240828101503.1478491-1-heiko@sntech.de> Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In contrast to fixed clocks that are described as ungateable, boards sometimes use additional oscillators for things like PCIe reference clocks, that need actual supplies to get enabled and enable-gpios to be toggled for them to work. This adds a driver for those generic gated-fixed-clocks that can show up in schematics looking like ---------------- Enable - | 100MHz,3.3V, | - VDD | 3225 | GND - | | - OUT ---------------- The new driver gets grouped together with the existing gpio-gate and gpio-mux, as it for one re-uses a lot of the gpio-gate functions and also in it's core it's just another gpio-controlled clock, just with a fixed rate and a regulator-supply added in. The regulator-API provides function stubs for the !CONFIG_REGULATOR case, so no special handling is necessary. Signed-off-by: Heiko Stuebner --- drivers/clk/clk-gpio.c | 182 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 182 insertions(+) diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c index cda362a2eca0..8bcdef340b4c 100644 --- a/drivers/clk/clk-gpio.c +++ b/drivers/clk/clk-gpio.c @@ -17,6 +17,7 @@ #include #include #include +#include /** * DOC: basic gpio gated clock which can be enabled and disabled @@ -239,3 +240,184 @@ static struct platform_driver gpio_clk_driver = { }, }; builtin_platform_driver(gpio_clk_driver); + +/** + * DOC: gated fixed clock, controlled with a gpio output and a regulator + * Traits of this clock: + * prepare - clk_prepare and clk_unprepare are function & control regulator + * optionally a gpio that can sleep + * enable - clk_enable and clk_disable are functional & control gpio + * rate - rate is fixed and set on clock generation + * parent - fixed clock is a root clock and has no parent. + */ + +/** + * struct clk_gate_fixed - gated-fixed-clock + * + * clk_gpio: instance of clk_gpio for gate-gpio + * supply: supply regulator + * rate: fixed rate + */ +struct clk_gated_fixed { + struct clk_gpio clk_gpio; + struct regulator *supply; + u32 rate; +}; + +#define to_clk_gated_fixed(_clk_gpio) container_of(_clk_gpio, struct clk_gated_fixed, clk_gpio) + +static unsigned long clk_gated_fixed_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return to_clk_gated_fixed(to_clk_gpio(hw))->rate; +} + +static int clk_gated_fixed_prepare(struct clk_hw *hw) +{ + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); + + if (!clk->supply) + return 0; + + return regulator_enable(clk->supply); +} + +static void clk_gated_fixed_unprepare(struct clk_hw *hw) +{ + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); + + if (!clk->supply) + return; + + regulator_disable(clk->supply); +} + +static int clk_gated_fixed_is_prepared(struct clk_hw *hw) +{ + struct clk_gated_fixed *clk = to_clk_gated_fixed(to_clk_gpio(hw)); + + if (!clk->supply) + return true; + + return regulator_is_enabled(clk->supply); +} + +/* + * Fixed gated clock with non-sleeping gpio. + * + * Prepare operation turns on the supply regulator + * and the enable operation switches the enable-gpio. + */ +const struct clk_ops clk_gated_fixed_ops = { + .prepare = clk_gated_fixed_prepare, + .unprepare = clk_gated_fixed_unprepare, + .is_prepared = clk_gated_fixed_is_prepared, + .enable = clk_gpio_gate_enable, + .disable = clk_gpio_gate_disable, + .is_enabled = clk_gpio_gate_is_enabled, + .recalc_rate = clk_gated_fixed_recalc_rate, +}; + +static int clk_sleeping_gated_fixed_prepare(struct clk_hw *hw) +{ + int ret; + + ret = clk_gated_fixed_prepare(hw); + if (ret) + return ret; + + ret = clk_sleeping_gpio_gate_prepare(hw); + if (ret) + clk_gated_fixed_unprepare(hw); + + return ret; +} + +static void clk_sleeping_gated_fixed_unprepare(struct clk_hw *hw) +{ + clk_gated_fixed_unprepare(hw); + clk_sleeping_gpio_gate_unprepare(hw); +} + +/* + * Fixed gated clock with non-sleeping gpio. + * + * Enabling the supply regulator and switching the enable-gpio happens + * both in the prepare step. + * is_prepared only needs to check the gpio state, as toggling the + * gpio is the last step when preparing. + */ +const struct clk_ops clk_sleeping_gated_fixed_ops = { + .prepare = clk_sleeping_gated_fixed_prepare, + .unprepare = clk_sleeping_gated_fixed_unprepare, + .is_prepared = clk_sleeping_gpio_gate_is_prepared, + .recalc_rate = clk_gated_fixed_recalc_rate, +}; + +static int clk_gated_fixed_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct clk_gated_fixed *clk; + const struct clk_ops *ops; + const char *clk_name; + int ret; + + clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL); + if (!clk) + return -ENOMEM; + + if (device_property_read_u32(dev, "clock-frequency", &clk->rate)) + return dev_err_probe(dev, -EIO, "failed to get clock-frequency"); + + ret = device_property_read_string(dev, "clock-output-names", &clk_name); + if (ret) + clk_name = fwnode_get_name(dev->fwnode); + + clk->supply = devm_regulator_get_optional(dev, "vdd"); + if (IS_ERR(clk->supply)) { + if (PTR_ERR(clk->supply) != -ENODEV) + return dev_err_probe(dev, PTR_ERR(clk->supply), + "failed to get regulator\n"); + clk->supply = NULL; + } + + clk->clk_gpio.gpiod = devm_gpiod_get_optional(dev, "enable", + GPIOD_OUT_LOW); + if (IS_ERR(clk->clk_gpio.gpiod)) + return dev_err_probe(dev, PTR_ERR(clk->clk_gpio.gpiod), + "failed to get gpio\n"); + + if (gpiod_cansleep(clk->clk_gpio.gpiod)) + ops = &clk_sleeping_gated_fixed_ops; + else + ops = &clk_gated_fixed_ops; + + clk->clk_gpio.hw.init = CLK_HW_INIT_NO_PARENT(clk_name, ops, 0); + + /* register the clock */ + ret = devm_clk_hw_register(dev, &clk->clk_gpio.hw); + if (ret) + return dev_err_probe(dev, ret, + "failed to register clock\n"); + + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, + &clk->clk_gpio.hw); + if (ret) + return dev_err_probe(dev, ret, + "failed to register clock provider\n"); + + return 0; +} + +static const struct of_device_id gated_fixed_clk_match_table[] = { + { .compatible = "gated-fixed-clock" }, +}; + +static struct platform_driver gated_fixed_clk_driver = { + .probe = clk_gated_fixed_probe, + .driver = { + .name = "gated-fixed-clk", + .of_match_table = gated_fixed_clk_match_table, + }, +}; +builtin_platform_driver(gated_fixed_clk_driver);