From patchwork Sat Apr 22 22:02:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?J=2E_Neusch=C3=A4fer?= X-Patchwork-Id: 13221131 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 048F3C77B78 for ; Sat, 22 Apr 2023 22:03:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229969AbjDVWDf (ORCPT ); Sat, 22 Apr 2023 18:03:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229900AbjDVWDa (ORCPT ); Sat, 22 Apr 2023 18:03:30 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.17.21]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FB60268B; Sat, 22 Apr 2023 15:03:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1682200973; i=j.neuschaefer@gmx.net; bh=luFx0eEkb2gHUO5NT2NcbEdgFA4+PBEtYkQCReQjKTU=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:In-Reply-To:References; b=nG98EC1TBH/nf1LdJ3pTodUgkpwhXhQgEN0npnJ9KvgYD2shs0Btu5tAxdqxBKWnd DGr0K0xANfttKiXLNJhr/7qvczxsGxCK13BIFPA7ZBSKBgs2ZV8u8W3KDhpQ/H1DNu ugpulBiMeHId2QUBbDnUiFvURKs/bPbLE+uNdArUPVn/+R/KvF4tJdDfkeHK6Mllxb e3QaNK6EcJeXOa676eDE+x4B0KK6xeP95moVV4pGQ0m0wcxX0cPH/4ZRgH6dG2X11v 7JogFDIhCksJd3j5FC38YzXf4HeraqdhOs0vGcVzkrpLFdSYPEVE4mMu6q+BLTPnuh SH9sKUEjKU9Gw== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from probook ([95.223.44.193]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1N6bjy-1qMsHC3w90-0186wL; Sun, 23 Apr 2023 00:02:53 +0200 From: =?utf-8?q?Jonathan_Neusch=C3=A4fer?= To: linux-clk@vger.kernel.org, openbmc@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, =?utf-8?q?Jonathan_Neusch=C3=A4fer?= , Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Daniel Lezcano , Thomas Gleixner , Philipp Zabel , Wim Van Sebroeck , Guenter Roeck , Christophe JAILLET Subject: [PATCH v7 2/2] clk: wpcm450: Add Nuvoton WPCM450 clock/reset controller driver Date: Sun, 23 Apr 2023 00:02:40 +0200 Message-Id: <20230422220240.322572-3-j.neuschaefer@gmx.net> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230422220240.322572-1-j.neuschaefer@gmx.net> References: <20230422220240.322572-1-j.neuschaefer@gmx.net> MIME-Version: 1.0 X-Provags-ID: V03:K1:D7KnbqU6dB59tqVSMj5Mbi6ZHfb2P+zuq7NwRkPho7n6g05XiGq oVMAFKAwPh8jCLX78OvhURaYDR6QfZFhhoCFb0dorU1DQIxv4Rn9M2DTxKIMJ4BteVzynjJ gPqwtIz5Lu0C68zqC9ZYB2iE2DlLqxYHJsTJm1nHdean3kJAib2JpDpoI0OGHlyIwqpLMTC BEuCtsMeFsbomqtw0y4fw== UI-OutboundReport: notjunk:1;M01:P0:J5+wu8KoULI=;Qrj34xLJKtmdetJ2kWbOyhO6wcU wD53lKm4G4NyeBZvwFGKI4OpcTdqd05MR3GqLdaZ4Y3Jn0qB/FInE1qm0xg+Eryj68MfyZHph R1tPzCcPA/Pt7yNr0vINXGpWkNMSdlpqgDc0AFN/5+uICCToCbnzfrkEihYceSIoOQ1TTaCFJ efi1f7QXB72Gjk8XI/+Bgt9xdxqhjI8O/P+drLas9R0rWLcVgtO7v/xyc1Kg7x4Gc2Y+t4rA2 CBTU2F0n0PXbQawchwCpVpac9uUbyTG6Ob4mraVxx3acwDN7KsnbbKc9OX/8zMwUPnudlqKNr PvGzjwU0fOv3ZpwAzDH1CFfnKrIx1ovi0sBHIagKM4AEnf1F+STK0vYSrGdu+p1vLZLWx0Gyr SALkGpzF0scqr7LCLH3IbMghUVh7C4Xw/SLMyvyWlGRM+WXzyr/BGSb//Z9xZkibw7fWwsHQv 13COwY9FVNxgRBMGb/6Ellm5r9JhPNxy/HnVicNjd1fkXcgbsbOYEm9mvqClKu6L3aAemd2kb IbCMJygyrKhcNZpQWKysnnEsRmhMbVftrMXcsXC6J6xVLvhF8pKGcvTYIdJTKDjXNfmo2d6pY pJ//wgfiYxraeSAOgnNxVQcQilmMKzXRVwgwmEgWFuj4SXvTuEa47VEIXBvz4xNJk9hmhvLGI I3qXFb+HbC5q2/AnNTnHG3jJLvUI/DIeOhp+sgRU0+whUm2fYLCqgB/mqy6itjySFYgQU0qUk bV0lygsmFW/A8iSKoe879I/QVvRerIm+eHReoWVvX523ZynZ1KyP0PMUupIR9pltJu5brbvU+ hJ/AATLkteg2nlnWrZ8cGELEznPQ4CaFphsE94taNGsvAplGnXfMEnWdOu5uMJftnJuEQXxiO dlwDfs8HwdNEcEGCI2dY0PJXh8eVWAjw0E6R0+7pIbKteYhO6oMFoU2aK/m7xI/7CpPLAUsiH 66v0a9omajs8Fwtm4ScpRReh3Ok= Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org This driver implements the following features w.r.t. the clock and reset controller in the WPCM450 SoC: - It calculates the rates for all clocks managed by the clock controller - It leaves the clock tree mostly unchanged, except that it enables/ disables clock gates based on usage. - It exposes the reset lines managed by the controller using the Generic Reset Controller subsystem NOTE: If the driver and the corresponding devicetree node are present, the driver will disable "unused" clocks. This is problem until the clock relations are properly declared in the devicetree (in a later patch). Until then, the clk_ignore_unused kernel parameter can be used as a workaround. Signed-off-by: Jonathan Neuschäfer Reviewed-by: Joel Stanley --- v7: - Simplify error handling by not deallocating resources v6: - Enable RESET_SIMPLE based on ARCH_WPCM450, not ARCH_NPCM, as suggested by Tomer Maimon v5: - https://lore.kernel.org/lkml/20221104161850.2889894-6-j.neuschaefer@gmx.net/ - Switch to using clk_parent_data v4: - https://lore.kernel.org/lkml/20220610072141.347795-6-j.neuschaefer@gmx.net/ - Fix reset controller initialization v3: - https://lore.kernel.org/lkml/20220508194333.2170161-7-j.neuschaefer@gmx.net/ - Change reference clock name from "refclk" to "ref" - Remove unused variable in return path of wpcm450_clk_register_pll - Remove unused divisor tables v2: - https://lore.kernel.org/lkml/20220429172030.398011-7-j.neuschaefer@gmx.net/ - no changes --- drivers/clk/Makefile | 1 + drivers/clk/clk-wpcm450.c | 374 ++++++++++++++++++++++++++++++++++++++ drivers/reset/Kconfig | 2 +- 3 files changed, 376 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/clk-wpcm450.c -- 2.39.2 diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index e3ca0d058a256..b58352d4d615d 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -75,6 +75,7 @@ obj-$(CONFIG_COMMON_CLK_RS9_PCIE) += clk-renesas-pcie.o obj-$(CONFIG_COMMON_CLK_VC5) += clk-versaclock5.o obj-$(CONFIG_COMMON_CLK_VC7) += clk-versaclock7.o obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o +obj-$(CONFIG_ARCH_WPCM450) += clk-wpcm450.o obj-$(CONFIG_COMMON_CLK_XGENE) += clk-xgene.o # please keep this section sorted lexicographically by directory path name diff --git a/drivers/clk/clk-wpcm450.c b/drivers/clk/clk-wpcm450.c new file mode 100644 index 0000000000000..6f6d8a1ea3484 --- /dev/null +++ b/drivers/clk/clk-wpcm450.c @@ -0,0 +1,374 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Nuvoton WPCM450 clock and reset controller driver. + * + * Copyright (C) 2022 Jonathan Neuschäfer + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct wpcm450_clk_pll { + struct clk_hw hw; + void __iomem *pllcon; + u8 flags; +}; + +#define to_wpcm450_clk_pll(_hw) container_of(_hw, struct wpcm450_clk_pll, hw) + +#define PLLCON_FBDV GENMASK(24, 16) +#define PLLCON_PRST BIT(13) +#define PLLCON_PWDEN BIT(12) +#define PLLCON_OTDV GENMASK(10, 8) +#define PLLCON_INDV GENMASK(5, 0) + +static unsigned long wpcm450_clk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + unsigned long fbdv, indv, otdv; + u64 rate; + u32 pllcon; + + if (parent_rate == 0) { + pr_err("%s: parent rate is zero", __func__); + return 0; + } + + pllcon = readl_relaxed(pll->pllcon); + + indv = FIELD_GET(PLLCON_INDV, pllcon) + 1; + fbdv = FIELD_GET(PLLCON_FBDV, pllcon) + 1; + otdv = FIELD_GET(PLLCON_OTDV, pllcon) + 1; + + rate = (u64)parent_rate * fbdv; + do_div(rate, indv * otdv); + + return rate; +} + +static int wpcm450_clk_pll_is_enabled(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + + return !(pllcon & PLLCON_PRST); +} + +static void wpcm450_clk_pll_disable(struct clk_hw *hw) +{ + struct wpcm450_clk_pll *pll = to_wpcm450_clk_pll(hw); + u32 pllcon; + + pllcon = readl_relaxed(pll->pllcon); + pllcon |= PLLCON_PRST | PLLCON_PWDEN; + writel(pllcon, pll->pllcon); +} + +static const struct clk_ops wpcm450_clk_pll_ops = { + .recalc_rate = wpcm450_clk_pll_recalc_rate, + .is_enabled = wpcm450_clk_pll_is_enabled, + .disable = wpcm450_clk_pll_disable +}; + +static struct clk_hw * +wpcm450_clk_register_pll(void __iomem *pllcon, const char *name, + const struct clk_parent_data *parent, unsigned long flags) +{ + struct wpcm450_clk_pll *pll; + struct clk_init_data init = {}; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &wpcm450_clk_pll_ops; + init.parent_data = parent; + init.num_parents = 1; + init.flags = flags; + + pll->pllcon = pllcon; + pll->hw.init = &init; + + ret = clk_hw_register(NULL, &pll->hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + return &pll->hw; +} + +#define REG_CLKEN 0x00 +#define REG_CLKSEL 0x04 +#define REG_CLKDIV 0x08 +#define REG_PLLCON0 0x0c +#define REG_PLLCON1 0x10 +#define REG_PMCON 0x14 +#define REG_IRQWAKECON 0x18 +#define REG_IRQWAKEFLAG 0x1c +#define REG_IPSRST 0x20 + +struct wpcm450_pll_data { + const char *name; + struct clk_parent_data parent; + unsigned int reg; + unsigned long flags; +}; + +static const struct wpcm450_pll_data pll_data[] = { + { "pll0", { .name = "ref" }, REG_PLLCON0, 0 }, + { "pll1", { .name = "ref" }, REG_PLLCON1, 0 }, +}; + +struct wpcm450_clksel_data { + const char *name; + const struct clk_parent_data *parents; + unsigned int num_parents; + const u32 *table; + int shift; + int width; + int index; + unsigned long flags; +}; + +static const u32 parent_table[] = { 0, 1, 2 }; + +static const struct clk_parent_data default_parents[] = { + { .name = "pll0" }, + { .name = "pll1" }, + { .name = "ref" }, +}; + +static const struct clk_parent_data huart_parents[] = { + { .name = "ref" }, + { .name = "refdiv2" }, +}; + +static const struct wpcm450_clksel_data clksel_data[] = { + { "cpusel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 0, 2, -1, CLK_IS_CRITICAL }, + { "clkout", default_parents, ARRAY_SIZE(default_parents), + parent_table, 2, 2, -1, 0 }, + { "usbphy", default_parents, ARRAY_SIZE(default_parents), + parent_table, 6, 2, -1, 0 }, + { "uartsel", default_parents, ARRAY_SIZE(default_parents), + parent_table, 8, 2, WPCM450_CLK_USBPHY, 0 }, + { "huartsel", huart_parents, ARRAY_SIZE(huart_parents), + parent_table, 10, 1, -1, 0 }, +}; + +static const struct clk_div_table div_fixed2[] = { + { .val = 0, .div = 2 }, + { } +}; + +struct wpcm450_clkdiv_data { + const char *name; + struct clk_parent_data parent; + int div_flags; + const struct clk_div_table *table; + int shift; + int width; + unsigned long flags; +}; + +static struct wpcm450_clkdiv_data clkdiv_data_early[] = { + { "refdiv2", { .name = "ref" }, 0, div_fixed2, 0, 0 }, +}; + +static const struct wpcm450_clkdiv_data clkdiv_data[] = { + { "cpu", { .name = "cpusel" }, 0, div_fixed2, 0, 0, CLK_IS_CRITICAL }, + { "adcdiv", { .name = "ref" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 28, 2, 0 }, + { "apb", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 26, 2, 0 }, + { "ahb", { .name = "cpu" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 24, 2, 0 }, + { "uart", { .name = "uartsel" }, 0, NULL, 16, 4, 0 }, + { "ahb3", { .name = "ahb" }, CLK_DIVIDER_POWER_OF_TWO, NULL, 8, 2, 0 }, +}; + +struct wpcm450_clken_data { + const char *name; + struct clk_parent_data parent; + int bitnum; + unsigned long flags; +}; + +static const struct wpcm450_clken_data clken_data[] = { + { "fiu", { .name = "ahb3" }, WPCM450_CLK_FIU, 0 }, + { "xbus", { .name = "ahb3" }, WPCM450_CLK_XBUS, 0 }, + { "kcs", { .name = "apb" }, WPCM450_CLK_KCS, 0 }, + { "shm", { .name = "ahb3" }, WPCM450_CLK_SHM, 0 }, + { "usb1", { .name = "ahb" }, WPCM450_CLK_USB1, 0 }, + { "emc0", { .name = "ahb" }, WPCM450_CLK_EMC0, 0 }, + { "emc1", { .name = "ahb" }, WPCM450_CLK_EMC1, 0 }, + { "usb0", { .name = "ahb" }, WPCM450_CLK_USB0, 0 }, + { "peci", { .name = "apb" }, WPCM450_CLK_PECI, 0 }, + { "aes", { .name = "apb" }, WPCM450_CLK_AES, 0 }, + { "uart0", { .name = "uart" }, WPCM450_CLK_UART0, 0 }, + { "uart1", { .name = "uart" }, WPCM450_CLK_UART1, 0 }, + { "smb2", { .name = "apb" }, WPCM450_CLK_SMB2, 0 }, + { "smb3", { .name = "apb" }, WPCM450_CLK_SMB3, 0 }, + { "smb4", { .name = "apb" }, WPCM450_CLK_SMB4, 0 }, + { "smb5", { .name = "apb" }, WPCM450_CLK_SMB5, 0 }, + { "huart", { .name = "huartsel" }, WPCM450_CLK_HUART, 0 }, + { "pwm", { .name = "apb" }, WPCM450_CLK_PWM, 0 }, + { "timer0", { .name = "refdiv2" }, WPCM450_CLK_TIMER0, 0 }, + { "timer1", { .name = "refdiv2" }, WPCM450_CLK_TIMER1, 0 }, + { "timer2", { .name = "refdiv2" }, WPCM450_CLK_TIMER2, 0 }, + { "timer3", { .name = "refdiv2" }, WPCM450_CLK_TIMER3, 0 }, + { "timer4", { .name = "refdiv2" }, WPCM450_CLK_TIMER4, 0 }, + { "mft0", { .name = "apb" }, WPCM450_CLK_MFT0, 0 }, + { "mft1", { .name = "apb" }, WPCM450_CLK_MFT1, 0 }, + { "wdt", { .name = "refdiv2" }, WPCM450_CLK_WDT, 0 }, + { "adc", { .name = "adcdiv" }, WPCM450_CLK_ADC, 0 }, + { "sdio", { .name = "ahb" }, WPCM450_CLK_SDIO, 0 }, + { "sspi", { .name = "apb" }, WPCM450_CLK_SSPI, 0 }, + { "smb0", { .name = "apb" }, WPCM450_CLK_SMB0, 0 }, + { "smb1", { .name = "apb" }, WPCM450_CLK_SMB1, 0 }, +}; + +static DEFINE_SPINLOCK(wpcm450_clk_lock); + +/* + * NOTE: Error handling is very rudimentary here. If the clock driver initial- + * ization fails, the system is probably in bigger trouble than what is caused + * by a few leaked resources. + */ + +static void __init wpcm450_clk_init(struct device_node *clk_np) +{ + struct clk_hw_onecell_data *clk_data; + static struct clk_hw **hws; + static struct clk_hw *hw; + void __iomem *clk_base; + int i, ret; + struct reset_simple_data *reset; + + clk_base = of_iomap(clk_np, 0); + if (!clk_base) { + pr_err("%pOFP: failed to map registers\n", clk_np); + of_node_put(clk_np); + return; + } + of_node_put(clk_np); + + clk_data = kzalloc(struct_size(clk_data, hws, WPCM450_NUM_CLKS), GFP_KERNEL); + if (!clk_data) + return; + + clk_data->num = WPCM450_NUM_CLKS; + hws = clk_data->hws; + + for (i = 0; i < WPCM450_NUM_CLKS; i++) + hws[i] = ERR_PTR(-ENOENT); + + // PLLs + for (i = 0; i < ARRAY_SIZE(pll_data); i++) { + const struct wpcm450_pll_data *data = &pll_data[i]; + + hw = wpcm450_clk_register_pll(clk_base + data->reg, data->name, + &data->parent, data->flags); + if (IS_ERR(hw)) { + pr_info("Failed to register PLL: %pe", hw); + return; + } + } + + // Early divisors (REF/2) + for (i = 0; i < ARRAY_SIZE(clkdiv_data_early); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data_early[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register div table: %pe\n", hw); + return; + } + } + + // Selects/muxes + for (i = 0; i < ARRAY_SIZE(clksel_data); i++) { + const struct wpcm450_clksel_data *data = &clksel_data[i]; + + hw = clk_hw_register_mux_parent_data(NULL, data->name, data->parents, + data->num_parents, data->flags, + clk_base + REG_CLKSEL, data->shift, + data->width, 0, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register mux: %pe\n", hw); + return; + } + if (data->index >= 0) + clk_data->hws[data->index] = hw; + } + + // Divisors + for (i = 0; i < ARRAY_SIZE(clkdiv_data); i++) { + const struct wpcm450_clkdiv_data *data = &clkdiv_data[i]; + + hw = clk_hw_register_divider_table_parent_data(NULL, data->name, &data->parent, + data->flags, clk_base + REG_CLKDIV, + data->shift, data->width, + data->div_flags, data->table, + &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register divider: %pe\n", hw); + return; + } + } + + // Enables/gates + for (i = 0; i < ARRAY_SIZE(clken_data); i++) { + const struct wpcm450_clken_data *data = &clken_data[i]; + + hw = clk_hw_register_gate_parent_data(NULL, data->name, &data->parent, data->flags, + clk_base + REG_CLKEN, data->bitnum, + data->flags, &wpcm450_clk_lock); + if (IS_ERR(hw)) { + pr_err("Failed to register gate: %pe\n", hw); + return; + } + clk_data->hws[data->bitnum] = hw; + } + + ret = of_clk_add_hw_provider(clk_np, of_clk_hw_onecell_get, clk_data); + if (ret) + pr_err("Failed to add DT provider: %d\n", ret); + + // Reset controller + reset = kzalloc(sizeof(*reset), GFP_KERNEL); + if (!reset) + return; + reset->rcdev.owner = THIS_MODULE; + reset->rcdev.nr_resets = WPCM450_NUM_RESETS; + reset->rcdev.ops = &reset_simple_ops; + reset->rcdev.of_node = clk_np; + reset->membase = clk_base + REG_IPSRST; + ret = reset_controller_register(&reset->rcdev); + if (ret) + pr_err("Failed to register reset controller: %d\n", ret); + + of_node_put(clk_np); +} + +CLK_OF_DECLARE(wpcm450_clk_init, "nuvoton,wpcm450-clk", wpcm450_clk_init); diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 2a52c990d4fec..16e111d213560 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -208,7 +208,7 @@ config RESET_SCMI config RESET_SIMPLE bool "Simple Reset Controller Driver" if COMPILE_TEST || EXPERT - default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC + default ARCH_ASPEED || ARCH_BCMBCA || ARCH_BITMAIN || ARCH_REALTEK || ARCH_STM32 || (ARCH_INTEL_SOCFPGA && ARM64) || ARCH_SUNXI || ARC || ARCH_WPCM450 depends on HAS_IOMEM help This enables a simple reset controller driver for reset lines that