From patchwork Sun Nov 23 04:33:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen-Yu Tsai X-Patchwork-Id: 5360211 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 07AD3C11AC for ; Sun, 23 Nov 2014 04:37:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 01DEC2021B for ; Sun, 23 Nov 2014 04:37:51 +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 C5BC320221 for ; Sun, 23 Nov 2014 04:37:49 +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 1XsOtv-0003gh-WE; Sun, 23 Nov 2014 04:35:56 +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 1XsOsq-0001aj-4e for linux-arm-kernel@lists.infradead.org; Sun, 23 Nov 2014 04:34:51 +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 4B228253E1; Sun, 23 Nov 2014 12:34:22 +0800 (CST) Received: by mirror2.csie.ntu.edu.tw (Postfix, from userid 1000) id 2B2E65F8B5; Sun, 23 Nov 2014 12:34:22 +0800 (CST) From: Chen-Yu Tsai To: Mike Turquette , Maxime Ripard , Emilio Lopez Subject: [PATCH v4 4/6] clk: sunxi: unify sun6i AHB1 clock with proper PLL6 pre-divider Date: Sun, 23 Nov 2014 12:33:23 +0800 Message-Id: <1416717205-15406-5-git-send-email-wens@csie.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1416717205-15406-1-git-send-email-wens@csie.org> References: <1416717205-15406-1-git-send-email-wens@csie.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141122_203448_511115_9F662EA2 X-CRM114-Status: GOOD ( 19.32 ) X-Spam-Score: -0.7 (/) Cc: Chen-Yu Tsai , 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=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, 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 This patch unifies the sun6i AHB1 clock, originally supported with separate mux and divider clks. It also adds support for the pre-divider on the PLL6 input, thus allowing the clock to be muxed to PLL6 with proper clock rate calculation. Signed-off-by: Chen-Yu Tsai --- Documentation/devicetree/bindings/clock/sunxi.txt | 2 +- drivers/clk/sunxi/clk-sunxi.c | 208 ++++++++++++++++++++++ 2 files changed, 209 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt index 67b2b99..9dc4f55 100644 --- a/Documentation/devicetree/bindings/clock/sunxi.txt +++ b/Documentation/devicetree/bindings/clock/sunxi.txt @@ -26,7 +26,7 @@ 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,sun6i-a31-ahb1-mux-clk" - for the AHB1 multiplexer on A31 + "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 "allwinner,sun9i-a80-ahb0-gates-clk" - for the AHB0 gates on A80 diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c index 5702025..337593c 100644 --- a/drivers/clk/sunxi/clk-sunxi.c +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -20,11 +20,219 @@ #include #include #include +#include #include "clk-factors.h" static DEFINE_SPINLOCK(clk_lock); +/** + * sun6i_a31_ahb1_clk_setup() - Setup function for a31 ahb1 composite clk + */ + +#define SUN6I_AHB1_MAX_PARENTS 4 +#define SUN6I_AHB1_MUX_PARENT_PLL6 3 +#define SUN6I_AHB1_MUX_SHIFT 12 +/* un-shifted mask is what mux_clk expects */ +#define SUN6I_AHB1_MUX_MASK 0x3 +#define SUN6I_AHB1_MUX_GET_PARENT(reg) ((reg >> SUN6I_AHB1_MUX_SHIFT) & \ + SUN6I_AHB1_MUX_MASK) + +#define SUN6I_AHB1_DIV_SHIFT 4 +#define SUN6I_AHB1_DIV_MASK (0x3 << SUN6I_AHB1_DIV_SHIFT) +#define SUN6I_AHB1_DIV_GET(reg) ((reg & SUN6I_AHB1_DIV_MASK) >> \ + SUN6I_AHB1_DIV_SHIFT) +#define SUN6I_AHB1_DIV_SET(reg, div) ((reg & ~SUN6I_AHB1_DIV_MASK) | \ + (div << SUN6I_AHB1_DIV_SHIFT)) +#define SUN6I_AHB1_PLL6_DIV_SHIFT 6 +#define SUN6I_AHB1_PLL6_DIV_MASK (0x3 << SUN6I_AHB1_PLL6_DIV_SHIFT) +#define SUN6I_AHB1_PLL6_DIV_GET(reg) ((reg & SUN6I_AHB1_PLL6_DIV_MASK) >> \ + SUN6I_AHB1_PLL6_DIV_SHIFT) +#define SUN6I_AHB1_PLL6_DIV_SET(reg, div) ((reg & ~SUN6I_AHB1_PLL6_DIV_MASK) | \ + (div << SUN6I_AHB1_PLL6_DIV_SHIFT)) + +struct sun6i_ahb1_clk { + struct clk_hw hw; + void __iomem *reg; +}; + +#define to_sun6i_ahb1_clk(_hw) container_of(_hw, struct sun6i_ahb1_clk, hw) + +static unsigned long sun6i_ahb1_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sun6i_ahb1_clk *ahb1 = to_sun6i_ahb1_clk(hw); + unsigned long rate; + u32 reg; + + /* Fetch the register value */ + reg = readl(ahb1->reg); + + /* apply pre-divider first if parent is pll6 */ + if (SUN6I_AHB1_MUX_GET_PARENT(reg) == SUN6I_AHB1_MUX_PARENT_PLL6) + parent_rate /= SUN6I_AHB1_PLL6_DIV_GET(reg) + 1; + + /* clk divider */ + rate = parent_rate >> SUN6I_AHB1_DIV_GET(reg); + + return rate; +} + +static long sun6i_ahb1_clk_round(unsigned long rate, u8 *divp, u8 *pre_divp, + u8 parent, unsigned long parent_rate) +{ + u8 div, calcp, calcm = 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 pll6 */ + if (parent == SUN6I_AHB1_MUX_PARENT_PLL6) { + if (div < 4) + calcp = 0; + else if (div / 2 < 4) + calcp = 1; + else if (div / 4 < 4) + calcp = 2; + else + calcp = 3; + + calcm = DIV_ROUND_UP(div, 1 << calcp); + } else { + calcp = __roundup_pow_of_two(div); + calcp = calcp > 3 ? 3 : calcp; + } + + /* we were asked to pass back divider values */ + if (divp) { + *divp = calcp; + *pre_divp = calcm - 1; + } + + return (parent_rate / calcm) >> calcp; +} + +static long sun6i_ahb1_clk_determine_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *best_parent_rate, + struct clk **best_parent_clk) +{ + struct clk *clk = hw->clk, *parent, *best_parent = NULL; + int i, num_parents; + unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0; + + /* find the parent that can help provide the fastest rate <= rate */ + num_parents = __clk_get_num_parents(clk); + for (i = 0; i < num_parents; i++) { + parent = clk_get_parent_by_index(clk, i); + if (!parent) + continue; + if (__clk_get_flags(clk) & CLK_SET_RATE_PARENT) + parent_rate = __clk_round_rate(parent, rate); + else + parent_rate = __clk_get_rate(parent); + + child_rate = sun6i_ahb1_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) + *best_parent_clk = best_parent; + *best_parent_rate = best; + + return best_child_rate; +} + +static int sun6i_ahb1_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sun6i_ahb1_clk *ahb1 = to_sun6i_ahb1_clk(hw); + unsigned long flags; + u8 div, pre_div, parent; + u32 reg; + + spin_lock_irqsave(&clk_lock, flags); + + reg = readl(ahb1->reg); + + /* need to know which parent is used to apply pre-divider */ + parent = SUN6I_AHB1_MUX_GET_PARENT(reg); + sun6i_ahb1_clk_round(rate, &div, &pre_div, parent, parent_rate); + + reg = SUN6I_AHB1_DIV_SET(reg, div); + reg = SUN6I_AHB1_PLL6_DIV_SET(reg, pre_div); + writel(reg, ahb1->reg); + + spin_unlock_irqrestore(&clk_lock, flags); + + return 0; +} + +static const struct clk_ops sun6i_ahb1_clk_ops = { + .determine_rate = sun6i_ahb1_clk_determine_rate, + .recalc_rate = sun6i_ahb1_clk_recalc_rate, + .set_rate = sun6i_ahb1_clk_set_rate, +}; + +static void __init sun6i_ahb1_clk_setup(struct device_node *node) +{ + struct clk *clk; + struct sun6i_ahb1_clk *ahb1; + struct clk_mux *mux; + const char *clk_name = node->name; + const char *parents[SUN6I_AHB1_MAX_PARENTS]; + void __iomem *reg; + int i = 0; + + reg = of_io_request_and_map(node, 0, of_node_full_name(node)); + + /* we have a mux, we will have >1 parents */ + while (i < SUN6I_AHB1_MAX_PARENTS && + (parents[i] = of_clk_get_parent_name(node, i)) != NULL) + i++; + + of_property_read_string(node, "clock-output-names", &clk_name); + + ahb1 = kzalloc(sizeof(struct sun6i_ahb1_clk), GFP_KERNEL); + if (!ahb1) + return; + + mux = kzalloc(sizeof(struct clk_mux), GFP_KERNEL); + if (!mux) { + kfree(ahb1); + return; + } + + /* set up clock properties */ + mux->reg = reg; + mux->shift = SUN6I_AHB1_MUX_SHIFT; + mux->mask = SUN6I_AHB1_MUX_MASK; + mux->lock = &clk_lock; + ahb1->reg = reg; + + clk = clk_register_composite(NULL, clk_name, parents, i, + &mux->hw, &clk_mux_ops, + &ahb1->hw, &sun6i_ahb1_clk_ops, + NULL, NULL, 0); + + if (!IS_ERR(clk)) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + } +} +CLK_OF_DECLARE(sun6i_a31_ahb1, "allwinner,sun6i-a31-ahb1-clk", sun6i_ahb1_clk_setup); + /* Maximum number of parents our clocks have */ #define SUNXI_MAX_PARENTS 5