From patchwork Fri May 22 20:41:12 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Thompson X-Patchwork-Id: 6467721 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 28F779F318 for ; Fri, 22 May 2015 20:44:24 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B56532047B for ; Fri, 22 May 2015 20:44:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4A01420522 for ; Fri, 22 May 2015 20:44:21 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Yvtlr-00087F-5x; Fri, 22 May 2015 20:42:19 +0000 Received: from mail-wg0-f51.google.com ([74.125.82.51]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YvtlX-00082T-5n for linux-arm-kernel@lists.infradead.org; Fri, 22 May 2015 20:42:01 +0000 Received: by wgez8 with SMTP id z8so27940476wge.0 for ; Fri, 22 May 2015 13:41:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=UK5VK8CEmgs7/cLpxouM0bVpXQMVOU9TGYxbjTo1Qes=; b=XyxaVnYVVnpX0EBLCfYGMz04mCWC6p1wuHku5/9D3KC0JRdwfIpJyZCFXz3M8Z2TP6 sB96D0C9ah6/8RxUzpa08sYn/i5fxxW8XldUzaCRe4/9hwDIXWjrJSLLuzlXCk8snVEJ zJdExhWJBjdZI7QyeywQFUbFptM4VQKM9aEokFjCDYuEREc2U6/bpws0wod7dW4QXyTG LnSaIyPXhJV0OLAjlSJENlLhUxfeIG8oPN8sQr5GIMLRSNY6c2EJiPScNm2VkiwOh6li VOgORr0lWokTEuv3l/Zo7xkmgzIlYyH3j7P5K74UDnB/G8gVxt9HaxHo05THIS0zMGcn JV5g== X-Gm-Message-State: ALoCoQmwaV+Wbk7hA8/Nkgw+NTwheFtFc2n5TYguoPG5Ix8MNz0MHQ0QxC+CcgK1lhgPS2b3Lhw/ X-Received: by 10.180.108.147 with SMTP id hk19mr10390947wib.51.1432327297124; Fri, 22 May 2015 13:41:37 -0700 (PDT) Received: from scallop.lan (cpc4-aztw19-0-0-cust71.18-1.cable.virginm.net. [82.33.25.72]) by mx.google.com with ESMTPSA id g11sm4759204wjr.25.2015.05.22.13.41.34 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 May 2015 13:41:36 -0700 (PDT) From: Daniel Thompson To: Mike Turquette , Stephen Boyd Subject: [RFC PATCH 2/3] clk: stm32: Add clock driver for STM32F4[23]xxx devices Date: Fri, 22 May 2015 21:41:12 +0100 Message-Id: <1432327273-6810-3-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1432327273-6810-1-git-send-email-daniel.thompson@linaro.org> References: <1432327273-6810-1-git-send-email-daniel.thompson@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150522_134159_562305_5DB3E161 X-CRM114-Status: GOOD ( 23.47 ) X-Spam-Score: -0.7 (/) Cc: Mark Rutland , devicetree@vger.kernel.org, Daniel Thompson , linaro-kernel@lists.linaro.org, Russell King , Pawel Moll , Ian Campbell , patches@linaro.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, Kamil Lulko , Rob Herring , Maxime Coquelin , Kumar Gala , Andreas Farber , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The driver supports decoding and statically modelling PLL state (i.e. we inherit state from bootloader) and provides support for all peripherals that support simple one-bit gated clocks. The covers all peripherals whose clocks come from the AHB, APB1 or APB2 buses. It has been tested (for non-regression only) on an STM32F429I-Discovery boards. The clock counts for TIM2, USART1 and SYSTICK are all set correctly and time and the wall clock looks OK when checked with a stopwatch. Signed-off-by: Daniel Thompson --- drivers/clk/Makefile | 1 + drivers/clk/clk-stm32f4.c | 365 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 366 insertions(+) create mode 100644 drivers/clk/clk-stm32f4.c diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 3d00c25..2c5433b 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_COMMON_CLK_RK808) += clk-rk808.o obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o +obj-$(CONFIG_ARCH_STM32) += clk-stm32f4.o obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o obj-$(CONFIG_ARCH_U300) += clk-u300.o obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c new file mode 100644 index 0000000..e494ccb --- /dev/null +++ b/drivers/clk/clk-stm32f4.c @@ -0,0 +1,365 @@ +/* + * Author: Daniel Thompson + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define STM32F4_RCC_PLLCFGR 0x04 +#define STM32F4_RCC_CFGR 0x08 +#define STM32F4_RCC_AHB1ENR 0x30 +#define STM32F4_RCC_AHB2ENR 0x34 +#define STM32F4_RCC_AHB3ENR 0x38 +#define STM32F4_RCC_APB1ENR 0x40 +#define STM32F4_RCC_APB2ENR 0x44 + +struct stm32f4_gate_data { + u8 offset; + u8 bit_idx; + const char *name; + const char *parent_name; + unsigned long flags; +}; + +static const struct stm32f4_gate_data stm32f4_gates[] __initconst = { + { STM32F4_RCC_AHB1ENR, 0, "gpioa", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 1, "gpiob", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 2, "gpioc", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 3, "gpiod", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 4, "gpioe", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 5, "gpiof", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 6, "gpiog", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 7, "gpioh", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 8, "gpioi", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 9, "gpioj", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 10, "gpiok", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 12, "crc", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 18, "bkpsra", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 20, "ccmdatam", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 21, "dma1", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 22, "dma2", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 23, "dma2d", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 25, "ethmac", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 26, "ethmactx", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 27, "ethmacrx", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 28, "ethmacptp", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 29, "otghs", "ahb_div" }, + { STM32F4_RCC_AHB1ENR, 30, "otghsulpi", "ahb_div" }, + + { STM32F4_RCC_AHB2ENR, 0, "dcmi", "ahb_div" }, + { STM32F4_RCC_AHB2ENR, 4, "cryp", "ahb_div" }, + { STM32F4_RCC_AHB2ENR, 5, "hash", "ahb_div" }, + { STM32F4_RCC_AHB2ENR, 6, "rng", "pll48" }, + { STM32F4_RCC_AHB2ENR, 7, "otgfs", "pll48" }, + + { STM32F4_RCC_AHB3ENR, 0, "fmc", "ahb_div", + CLK_IGNORE_UNUSED }, + + { STM32F4_RCC_APB1ENR, 0, "tim2", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 1, "tim3", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 2, "tim4", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 3, "tim5", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 4, "tim6", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 5, "tim7", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 6, "tim12", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 7, "tim13", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 8, "tim14", "apb1_mul" }, + { STM32F4_RCC_APB1ENR, 11, "wwdg", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 14, "spi2", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 15, "spi3", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 17, "uart2", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 18, "uart3", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 19, "uart4", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 20, "uart5", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 21, "i2c1", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 22, "i2c2", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 23, "i2c3", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 25, "can1", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 26, "can2", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 28, "pwr", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 29, "dac", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 30, "uart7", "apb1_div" }, + { STM32F4_RCC_APB1ENR, 31, "uart8", "apb1_div" }, + + { STM32F4_RCC_APB2ENR, 0, "tim1", "apb2_mul" }, + { STM32F4_RCC_APB2ENR, 1, "tim8", "apb2_mul" }, + { STM32F4_RCC_APB2ENR, 4, "usart1", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 5, "usart6", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 8, "adc1", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 9, "adc2", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 10, "adc3", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 11, "sdio", "pll48" }, + { STM32F4_RCC_APB2ENR, 12, "spi1", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 13, "spi4", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 14, "syscfg", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 16, "tim9", "apb2_mul" }, + { STM32F4_RCC_APB2ENR, 17, "tim10", "apb2_mul" }, + { STM32F4_RCC_APB2ENR, 18, "tim11", "apb2_mul" }, + { STM32F4_RCC_APB2ENR, 20, "spi5", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 21, "spi6", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 22, "sai1", "apb2_div" }, + { STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" }, +}; + +/* + * MAX_CLKS is the maximum value in the enumeration below plus the combined + * hweight of stm32f42xx_gate_map (plus one). + */ +#define MAX_CLKS 74 + +enum { SYSTICK, FCLK }; + +/* + * This bitmask tells us which bit offsets (0..192) on STM32F4[23]xxx + * have gate bits associated with them. Its combined hweight is 71. + */ +static const u64 stm32f42xx_gate_map[] = { 0x000000f17ef417ff, + 0x0000000000000001, + 0x04777f33f6fec9ff }; + +static struct clk *clks[MAX_CLKS]; +static DEFINE_SPINLOCK(stm32f4_clk_lock); +static void __iomem *base; + +/* + * "Multiplier" device for APBx clocks. + * + * The APBx dividers are power-of-two dividers and, if *not* running in 1:1 + * mode, they also tap out the one of the low order state bits to run the + * timers. ST datasheets represent this feature as a (conditional) clock + * multiplier. + */ +struct clk_apb_mul { + struct clk_hw hw; + u8 bit_idx; +}; + +#define to_clk_apb_mul(_hw) container_of(_hw, struct clk_apb_mul, hw) + +static unsigned long clk_apb_mul_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_apb_mul *am = to_clk_apb_mul(hw); + + if (readl(base + STM32F4_RCC_CFGR) & BIT(am->bit_idx)) + return parent_rate * 2; + + return parent_rate; +} + +static long clk_apb_mul_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_apb_mul *am = to_clk_apb_mul(hw); + unsigned long mult = 1; + + if (readl(base + STM32F4_RCC_CFGR) & BIT(am->bit_idx)) + mult *= 2; + + if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) { + unsigned long best_parent = rate / mult; + + *prate = + __clk_round_rate(__clk_get_parent(hw->clk), best_parent); + } + + return *prate * mult; +} + +static int clk_apb_mul_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + return 0; +} + +static struct clk_ops clk_apb_mul_factor_ops = { + .round_rate = clk_apb_mul_round_rate, + .set_rate = clk_apb_mul_set_rate, + .recalc_rate = clk_apb_mul_recalc_rate, +}; + +struct clk *clk_register_apb_mul(struct device *dev, const char *name, + const char *parent_name, unsigned long flags, + u8 bit_idx) +{ + struct clk_apb_mul *am; + struct clk_init_data init; + struct clk *clk; + + am = kzalloc(sizeof(*am), GFP_KERNEL); + if (!am) + return ERR_PTR(-ENOMEM); + + am->bit_idx = bit_idx; + am->hw.init = &init; + + init.name = name; + init.ops = &clk_apb_mul_factor_ops; + init.flags = flags | CLK_IS_BASIC; + init.parent_names = &parent_name; + init.num_parents = 1; + + clk = clk_register(dev, &am->hw); + + if (IS_ERR(clk)) + kfree(am); + + return clk; +} + +/* + * Decode current PLL state and (statically) model the state we inherit from + * the bootloader. + */ +static void stm32f4_rcc_register_pll(const char *hse_clk, const char *hsi_clk) +{ + unsigned long pllcfgr = readl(base + STM32F4_RCC_PLLCFGR); + + unsigned long pllm = pllcfgr & 0x3f; + unsigned long plln = (pllcfgr >> 6) & 0x1ff; + unsigned long pllp = BIT(((pllcfgr >> 16) & 3) + 1); + const char *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk; + unsigned long pllq = (pllcfgr >> 24) & 0xf; + + clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm); + clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp); + clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq); +} + +/* + * Converts the primary and secondary indices (as they appear in DT) to an + * offset into our struct clock array. + */ +static unsigned int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary) +{ + u64 table[ARRAY_SIZE(stm32f42xx_gate_map)]; + + if (primary == 1) { + BUG_ON(secondary > FCLK); + return secondary; + } + + memcpy(table, stm32f42xx_gate_map, sizeof(table)); + + /* only bits set in table can be used as indices */ + BUG_ON(secondary > 8 * sizeof(table) || + 0 == (table[BIT_ULL_WORD(secondary)] & BIT_ULL_MASK(secondary))); + + /* mask out bits above our current index */ + table[BIT_ULL_WORD(secondary)] &= + GENMASK_ULL(secondary % BITS_PER_LONG_LONG, 0); + + return FCLK + hweight64(table[0]) + + (BIT_ULL_WORD(secondary) >= 1 ? hweight64(table[1]) : 0) + + (BIT_ULL_WORD(secondary) >= 2 ? hweight64(table[2]) : 0); +} + +struct clk *stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data) +{ + return clks[stm32f4_rcc_lookup_clk_idx(clkspec->args[0], + clkspec->args[1])]; +} + +static const char __initdata *sys_parents[] = { "hsi", NULL, "pll" }; + +static struct clk_div_table ahb_div_table[] = { + { 0x0, 1 }, { 0x1, 1 }, { 0x2, 1 }, { 0x3, 1 }, + { 0x4, 1 }, { 0x5, 1 }, { 0x6, 1 }, { 0x7, 1 }, + { 0x8, 2 }, { 0x9, 4 }, { 0xa, 8 }, { 0xb, 16 }, + { 0xc, 64 }, { 0xd, 128 }, { 0xe, 256 }, { 0xf, 512 }, + { 0 }, +}; + +static struct clk_div_table apb_div_table[] = { + { 0, 1 }, { 0, 1 }, { 0, 1 }, { 0, 1 }, + { 4, 2 }, { 5, 4 }, { 6, 8 }, { 7, 16 }, + { 0 }, +}; + +static void __init stm32f4_rcc_init(struct device_node *np) +{ + struct clk *clk; + const char *hse_clk; + int n; + + base = of_iomap(np, 0); + if (!base) { + pr_err("%s: unable to map resource", np->name); + return; + } + + hse_clk = of_clk_get_parent_name(np, 0); + + clk_register_fixed_rate_with_accuracy(NULL, "hsi", NULL, 0, + 16000000, 160000); + stm32f4_rcc_register_pll(hse_clk, "hsi"); + + sys_parents[1] = hse_clk; + clk_register_mux_table( + NULL, "sys", sys_parents, ARRAY_SIZE(sys_parents), 0, + base + STM32F4_RCC_CFGR, 0, 3, 0, NULL, &stm32f4_clk_lock); + + clk_register_divider_table(NULL, "ahb_div", "sys", + CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR, + 4, 4, 0, ahb_div_table, &stm32f4_clk_lock); + + clk_register_divider_table(NULL, "apb1_div", "ahb_div", + CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR, + 10, 3, 0, apb_div_table, &stm32f4_clk_lock); + clk_register_apb_mul(NULL, "apb1_mul", "apb1_div", + CLK_SET_RATE_PARENT, 12); + + clk_register_divider_table(NULL, "apb2_div", "ahb_div", + CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR, + 13, 3, 0, apb_div_table, &stm32f4_clk_lock); + clk_register_apb_mul(NULL, "apb2_mul", "apb2_div", + CLK_SET_RATE_PARENT, 15); + + clks[SYSTICK] = clk_register_fixed_factor(NULL, "systick", "ahb_div", + 0, 1, 8); + clks[FCLK] = clk_register_fixed_factor(NULL, "fclk", "ahb_div", + 0, 1, 1); + + for (n = 0; n < ARRAY_SIZE(stm32f4_gates); n++) { + const struct stm32f4_gate_data *gd = &stm32f4_gates[n]; + unsigned int secondary = + 8 * (gd->offset - STM32F4_RCC_AHB1ENR) + gd->bit_idx; + unsigned int idx = stm32f4_rcc_lookup_clk_idx(0, secondary); + + clks[idx] = clk_register_gate( + NULL, gd->name, gd->parent_name, gd->flags, + base + gd->offset, gd->bit_idx, 0, &stm32f4_clk_lock); + + if (IS_ERR(clks[n])) { + pr_err("%s: Unable to register leaf clock %s\n", + np->full_name, gd->name); + goto fail; + } + } + + of_clk_add_provider(np, stm32f4_rcc_lookup_clk, NULL); + return; +fail: + iounmap(base); +} +CLK_OF_DECLARE(stm32f4_rcc, "st,stm32f42xx-rcc", stm32f4_rcc_init);