From patchwork Tue Nov 24 09:32:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen-Yu Tsai X-Patchwork-Id: 7688831 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 EC4CD9F4F5 for ; Tue, 24 Nov 2015 09:36:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C438D20804 for ; Tue, 24 Nov 2015 09:36:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A968B20801 for ; Tue, 24 Nov 2015 09:36:38 +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 1a19zk-0002Aw-7y; Tue, 24 Nov 2015 09:34:40 +0000 Received: from smtp.csie.ntu.edu.tw ([140.112.30.61]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1a19xr-0000ko-UC for linux-arm-kernel@lists.infradead.org; Tue, 24 Nov 2015 09:32:47 +0000 Received: from mirror2.csie.ntu.edu.tw (mirror2.csie.ntu.edu.tw [140.112.30.76]) (Authenticated sender: b93043) by smtp.csie.ntu.edu.tw (Postfix) with ESMTPSA id C996B214F6; Tue, 24 Nov 2015 17:32:21 +0800 (CST) Received: by mirror2.csie.ntu.edu.tw (Postfix, from userid 1000) id 9AFA05F924; Tue, 24 Nov 2015 17:32:21 +0800 (CST) From: Chen-Yu Tsai To: Maxime Ripard , Michael Turquette , Stephen Boyd , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala Subject: [PATCH v3 3/5] clk: sunxi: Add sun9i A80 cpus (cpu special) clock support Date: Tue, 24 Nov 2015 17:32:14 +0800 Message-Id: <1448357536-26613-4-git-send-email-wens@csie.org> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1448357536-26613-1-git-send-email-wens@csie.org> References: <1448357536-26613-1-git-send-email-wens@csie.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151124_013244_334866_F3D70AC4 X-CRM114-Status: GOOD ( 21.78 ) X-Spam-Score: -4.8 (----) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chen-Yu Tsai , linux-sunxi@googlegroups.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org 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=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 "cpus" clock is the clock for the embedded processor in the A80. It is also part of the PRCM clock tree. This clock includes a pre- divider on one of its inputs. For now we are using a custom clock driver for it. In the future we may want to develop a generalized driver for these types of clocks, which also includes the AHB clock driver on sun[5678]i. Signed-off-by: Chen-Yu Tsai --- Hi Maxime, I'll do the factors clock refactoring mentioned during the discussion around v2 later on. --- Documentation/devicetree/bindings/clock/sunxi.txt | 1 + drivers/clk/sunxi/Makefile | 1 + drivers/clk/sunxi/clk-sun9i-cpus.c | 240 ++++++++++++++++++++++ 3 files changed, 242 insertions(+) create mode 100644 drivers/clk/sunxi/clk-sun9i-cpus.c diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt index b6859ed6913f..153ac72869e8 100644 --- a/Documentation/devicetree/bindings/clock/sunxi.txt +++ b/Documentation/devicetree/bindings/clock/sunxi.txt @@ -27,6 +27,7 @@ Required properties: "allwinner,sun5i-a10s-ahb-gates-clk" - for the AHB gates on A10s "allwinner,sun7i-a20-ahb-gates-clk" - for the AHB gates on A20 "allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31 + "allwinner,sun9i-a80-cpus-clk" - for the CPUS on A80 "allwinner,sun6i-a31-ahb1-clk" - for the AHB1 clock on A31 "allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31 "allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23 diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile index 121333ce34ea..07d914c3f6d1 100644 --- a/drivers/clk/sunxi/Makefile +++ b/drivers/clk/sunxi/Makefile @@ -13,6 +13,7 @@ obj-y += clk-simple-gates.o obj-y += clk-sun8i-apb0.o obj-y += clk-sun8i-mbus.o obj-y += clk-sun9i-core.o +obj-y += clk-sun9i-cpus.o obj-y += clk-sun9i-mmc.o obj-y += clk-usb.o diff --git a/drivers/clk/sunxi/clk-sun9i-cpus.c b/drivers/clk/sunxi/clk-sun9i-cpus.c new file mode 100644 index 000000000000..7626d2194b96 --- /dev/null +++ b/drivers/clk/sunxi/clk-sun9i-cpus.c @@ -0,0 +1,240 @@ +/* + * Copyright (C) 2015 Chen-Yu Tsai + * + * Chen-Yu Tsai + * + * Allwinner A80 CPUS clock driver + * + */ + +#include +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(sun9i_a80_cpus_lock); + +/** + * sun9i_a80_cpus_clk_setup() - Setup function for a80 cpus composite clk + */ + +#define SUN9I_CPUS_MAX_PARENTS 4 +#define SUN9I_CPUS_MUX_PARENT_PLL4 3 +#define SUN9I_CPUS_MUX_SHIFT 16 +#define SUN9I_CPUS_MUX_MASK GENMASK(17, 16) +#define SUN9I_CPUS_MUX_GET_PARENT(reg) ((reg & SUN9I_CPUS_MUX_MASK) >> \ + SUN9I_CPUS_MUX_SHIFT) + +#define SUN9I_CPUS_DIV_SHIFT 4 +#define SUN9I_CPUS_DIV_MASK GENMASK(5, 4) +#define SUN9I_CPUS_DIV_GET(reg) ((reg & SUN9I_CPUS_DIV_MASK) >> \ + SUN9I_CPUS_DIV_SHIFT) +#define SUN9I_CPUS_DIV_SET(reg, div) ((reg & ~SUN9I_CPUS_DIV_MASK) | \ + (div << SUN9I_CPUS_DIV_SHIFT)) +#define SUN9I_CPUS_PLL4_DIV_SHIFT 8 +#define SUN9I_CPUS_PLL4_DIV_MASK GENMASK(12, 8) +#define SUN9I_CPUS_PLL4_DIV_GET(reg) ((reg & SUN9I_CPUS_PLL4_DIV_MASK) >> \ + SUN9I_CPUS_PLL4_DIV_SHIFT) +#define SUN9I_CPUS_PLL4_DIV_SET(reg, div) ((reg & ~SUN9I_CPUS_PLL4_DIV_MASK) | \ + (div << SUN9I_CPUS_PLL4_DIV_SHIFT)) + +struct sun9i_a80_cpus_clk { + struct clk_hw hw; + void __iomem *reg; +}; + +#define to_sun9i_a80_cpus_clk(_hw) container_of(_hw, struct sun9i_a80_cpus_clk, hw) + +static unsigned long sun9i_a80_cpus_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sun9i_a80_cpus_clk *cpus = to_sun9i_a80_cpus_clk(hw); + unsigned long rate; + u32 reg; + + /* Fetch the register value */ + reg = readl(cpus->reg); + + /* apply pre-divider first if parent is pll4 */ + if (SUN9I_CPUS_MUX_GET_PARENT(reg) == SUN9I_CPUS_MUX_PARENT_PLL4) + parent_rate /= SUN9I_CPUS_PLL4_DIV_GET(reg) + 1; + + /* clk divider */ + rate = parent_rate / (SUN9I_CPUS_DIV_GET(reg) + 1); + + return rate; +} + +static long sun9i_a80_cpus_clk_round(unsigned long rate, u8 *divp, u8 *pre_divp, + u8 parent, unsigned long parent_rate) +{ + u8 div, pre_div = 1; + + /* + * clock can only divide, so we will never be able to achieve + * frequencies higher than the parent frequency + */ + if (parent_rate && rate > parent_rate) + rate = parent_rate; + + div = DIV_ROUND_UP(parent_rate, rate); + + /* calculate pre-divider if parent is pll4 */ + if (parent == SUN9I_CPUS_MUX_PARENT_PLL4 && div > 4) { + /* pre-divider is 1 ~ 32 */ + if (div < 32) { + pre_div = div; + div = 1; + } else if (div < 64) { + pre_div = DIV_ROUND_UP(div, 2); + div = 2; + } else if (div < 96) { + pre_div = DIV_ROUND_UP(div, 3); + div = 3; + } else { + pre_div = DIV_ROUND_UP(div, 4); + div = 4; + } + } + + /* we were asked to pass back divider values */ + if (divp) { + *divp = div - 1; + *pre_divp = pre_div - 1; + } + + return parent_rate / pre_div / div; +} + +static int sun9i_a80_cpus_clk_determine_rate(struct clk_hw *clk, + struct clk_rate_request *req) +{ + struct clk_hw *parent, *best_parent = NULL; + int i, num_parents; + unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0; + unsigned long rate = req->rate; + + /* find the parent that can help provide the fastest rate <= rate */ + num_parents = clk_hw_get_num_parents(clk); + for (i = 0; i < num_parents; i++) { + parent = clk_hw_get_parent_by_index(clk, i); + if (!parent) + continue; + if (clk_hw_get_flags(clk) & CLK_SET_RATE_PARENT) + parent_rate = clk_hw_round_rate(parent, rate); + else + parent_rate = clk_hw_get_rate(parent); + + child_rate = sun9i_a80_cpus_clk_round(rate, NULL, NULL, i, + parent_rate); + + if (child_rate <= rate && child_rate > best_child_rate) { + best_parent = parent; + best = parent_rate; + best_child_rate = child_rate; + } + } + + if (!best_parent) + return -EINVAL; + + req->best_parent_hw = best_parent; + req->best_parent_rate = best; + req->rate = best_child_rate; + + return 0; +} + +static int sun9i_a80_cpus_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sun9i_a80_cpus_clk *cpus = to_sun9i_a80_cpus_clk(hw); + unsigned long flags; + u8 div, pre_div, parent; + u32 reg; + + spin_lock_irqsave(&sun9i_a80_cpus_lock, flags); + + reg = readl(cpus->reg); + + /* need to know which parent is used to apply pre-divider */ + parent = SUN9I_CPUS_MUX_GET_PARENT(reg); + sun9i_a80_cpus_clk_round(rate, &div, &pre_div, parent, parent_rate); + + reg = SUN9I_CPUS_DIV_SET(reg, div); + reg = SUN9I_CPUS_PLL4_DIV_SET(reg, pre_div); + writel(reg, cpus->reg); + + spin_unlock_irqrestore(&sun9i_a80_cpus_lock, flags); + + return 0; +} + +static const struct clk_ops sun9i_a80_cpus_clk_ops = { + .determine_rate = sun9i_a80_cpus_clk_determine_rate, + .recalc_rate = sun9i_a80_cpus_clk_recalc_rate, + .set_rate = sun9i_a80_cpus_clk_set_rate, +}; + +static void sun9i_a80_cpus_setup(struct device_node *node) +{ + const char *clk_name = node->name; + const char *parents[SUN9I_CPUS_MAX_PARENTS]; + struct resource res; + struct sun9i_a80_cpus_clk *cpus; + struct clk_mux *mux; + struct clk *clk; + int ret; + + cpus = kzalloc(sizeof(*cpus), GFP_KERNEL); + if (!cpus) + return; + + cpus->reg = of_io_request_and_map(node, 0, of_node_full_name(node)); + if (IS_ERR(cpus->reg)) + goto err_free_cpus; + + of_property_read_string(node, "clock-output-names", &clk_name); + + /* we have a mux, we will have >1 parents */ + ret = of_clk_parent_fill(node, parents, SUN9I_CPUS_MAX_PARENTS); + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + goto err_unmap; + + /* set up clock properties */ + mux->reg = cpus->reg; + mux->shift = SUN9I_CPUS_MUX_SHIFT; + /* un-shifted mask is what mux_clk expects */ + mux->mask = SUN9I_CPUS_MUX_MASK >> SUN9I_CPUS_MUX_SHIFT; + mux->lock = &sun9i_a80_cpus_lock; + + clk = clk_register_composite(NULL, clk_name, parents, ret, + &mux->hw, &clk_mux_ops, + &cpus->hw, &sun9i_a80_cpus_clk_ops, + NULL, NULL, 0); + if (IS_ERR(clk)) + goto err_free_mux; + + ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); + if (ret) + goto err_unregister; + + return; + +err_unregister: + clk_unregister(clk); +err_free_mux: + kfree(mux); +err_unmap: + iounmap(cpus->reg); + of_address_to_resource(node, 0, &res); + release_mem_region(res.start, resource_size(&res)); +err_free_cpus: + kfree(cpus); +} +CLK_OF_DECLARE(sun9i_a80_cpus, "allwinner,sun9i-a80-cpus-clk", + sun9i_a80_cpus_setup);