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[209.132.180.67]) by mx.google.com with ESMTP id u15-v6si17409695pfk.82.2018.05.22.09.35.14; Tue, 22 May 2018 09:35:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@baylibre-com.20150623.gappssmtp.com header.s=20150623 header.b=j7AGZ7Hb; spf=pass (google.com: best guess record for domain of devicetree-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=devicetree-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751440AbeEVQfM (ORCPT + 5 others); Tue, 22 May 2018 12:35:12 -0400 Received: from mail-wr0-f193.google.com ([209.85.128.193]:44987 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751655AbeEVQfH (ORCPT ); Tue, 22 May 2018 12:35:07 -0400 Received: by mail-wr0-f193.google.com with SMTP id y15-v6so21322100wrg.11 for ; Tue, 22 May 2018 09:35:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=b8dM/2/dtbVqkmXdUuQl7U0i+Wwu8WdRh/G/jtLeuuY=; b=j7AGZ7HbVoXEEhsZXulI0mHkXplVlESQDZZmn/5MAAn03kvOcQsIlpnXVyejGLlS0f fnfsz+tJh7mQQ6C7m96gzuzZA1iswU/OzFLK7/HmCk+psuZOb7QRJw8/UqsT0cx81EAD tjJlRZDpvwz73aPp+h2ArBH7lkyRUMxboWsfiWeAaQeqCxTxC4TYjI52vS8fUQT3YEzJ lQYIwIDMcLE9fjNW5wJY8LPEbo4LTUedVCmYO9C5gMCHwukZVfgVAYkJYwAw77uMVnOQ uP/9pzva/58QmPCLDAwLohCL8q9JYYbvZ4YcsiYnVkwjWbNdRKKckePU1+HrrUZMmkD1 u8ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=b8dM/2/dtbVqkmXdUuQl7U0i+Wwu8WdRh/G/jtLeuuY=; b=bN8kl6KLmAMO1PtFWEr5dp8Ch+emZtcwrpY9nuV8T13tFAMoC1N2VGOQcn2qTrNCCa /JLraRRBH5QgERrJNFX5LkVWEVp5ne9hpEnbNFcFeeOQsUj0efRN4ljXxRDJ+n/16z7K k4hIXaR6SP5dgGQE9HNyxDmkPi3ivpHOEh4RdLDT9E7W7csMkKEMmH91ioaL1PPu3a4L ElFLmqcbQGJzLoz6zxpNSphHL9rN1Lq/3UO5YBOkkOHdPgoQn4tV74OGo+/BTTxH3u1V 1sXNV5Kv5T9OGypzV/P/JPLavn5GYOT/uhEjgLuXCL2JR+LbpYSSKlX/60ZlK8gB8EG0 tLpg== X-Gm-Message-State: ALKqPwcastbnN9WTNDxf7zEoIi/y+EbcAy1fCrRJlw0znm+neNQyxs6u nJU3hH0klJMnl3yJsbDXHgPNVA== X-Received: by 2002:adf:b509:: with SMTP id a9-v6mr19470563wrd.191.1527006906315; Tue, 22 May 2018 09:35:06 -0700 (PDT) Received: from boomer.baylibre.local ([90.63.244.31]) by smtp.googlemail.com with ESMTPSA id h8-v6sm294062wmc.16.2018.05.22.09.35.05 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 22 May 2018 09:35:05 -0700 (PDT) From: Jerome Brunet To: Neil Armstrong , Carlo Caione , Kevin Hilman Cc: Jerome Brunet , Michael Turquette , Stephen Boyd , linux-amlogic@lists.infradead.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/6] clk: meson: add axg audio sclk divider driver Date: Tue, 22 May 2018 18:34:55 +0200 Message-Id: <20180522163457.13834-5-jbrunet@baylibre.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180522163457.13834-1-jbrunet@baylibre.com> References: <20180522163457.13834-1-jbrunet@baylibre.com> Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add a driver to control the clock divider found in the sample clock generator of the axg audio clock controller. The sclk divider accumulates specific features which make the generic divider unsuitable to control it: - zero based divider (div = val + 1), but zero value gates the clock, so minimum divider value is 2. - lrclk variant may adjust the duty cycle depending the divider value and the 'hi' value. Acked-by: Neil Armstrong Signed-off-by: Jerome Brunet --- drivers/clk/meson/Makefile | 2 +- drivers/clk/meson/clkc-audio.h | 8 ++ drivers/clk/meson/sclk-div.c | 243 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 252 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/meson/sclk-div.c -- 2.14.3 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile index 74ec070b0974..1574e3f0de5c 100644 --- a/drivers/clk/meson/Makefile +++ b/drivers/clk/meson/Makefile @@ -4,7 +4,7 @@ obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-audio-divider.o obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-phase.o -obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o +obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o sclk-div.o obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o diff --git a/drivers/clk/meson/clkc-audio.h b/drivers/clk/meson/clkc-audio.h index 286ff1201258..0a7c157ebf81 100644 --- a/drivers/clk/meson/clkc-audio.h +++ b/drivers/clk/meson/clkc-audio.h @@ -15,6 +15,14 @@ struct meson_clk_triphase_data { struct parm ph2; }; +struct meson_sclk_div_data { + struct parm div; + struct parm hi; + unsigned int cached_div; + struct clk_duty cached_duty; +}; + extern const struct clk_ops meson_clk_triphase_ops; +extern const struct clk_ops meson_sclk_div_ops; #endif /* __MESON_CLKC_AUDIO_H */ diff --git a/drivers/clk/meson/sclk-div.c b/drivers/clk/meson/sclk-div.c new file mode 100644 index 000000000000..bc64019b8eeb --- /dev/null +++ b/drivers/clk/meson/sclk-div.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +/* + * Copyright (c) 2018 BayLibre, SAS. + * Author: Jerome Brunet + * + * Sample clock generator divider: + * This HW divider gates with value 0 but is otherwise a zero based divider: + * + * val >= 1 + * divider = val + 1 + * + * The duty cycle may also be set for the LR clock variant. The duty cycle + * ratio is: + * + * hi = [0 - val] + * duty_cycle = (1 + hi) / (1 + val) + */ + +#include "clkc-audio.h" + +static inline struct meson_sclk_div_data * +meson_sclk_div_data(struct clk_regmap *clk) +{ + return (struct meson_sclk_div_data *)clk->data; +} + +static int sclk_div_maxval(struct meson_sclk_div_data *sclk) +{ + return (1 << sclk->div.width) - 1; +} + +static int sclk_div_maxdiv(struct meson_sclk_div_data *sclk) +{ + return sclk_div_maxval(sclk) + 1; +} + +static int sclk_div_getdiv(struct clk_hw *hw, unsigned long rate, + unsigned long prate, int maxdiv) +{ + int div = DIV_ROUND_CLOSEST_ULL((u64)prate, rate); + + return clamp(div, 2, maxdiv); +} + +static int sclk_div_bestdiv(struct clk_hw *hw, unsigned long rate, + unsigned long *prate, + struct meson_sclk_div_data *sclk) +{ + struct clk_hw *parent = clk_hw_get_parent(hw); + int bestdiv = 0, i; + unsigned long maxdiv, now, parent_now; + unsigned long best = 0, best_parent = 0; + + if (!rate) + rate = 1; + + maxdiv = sclk_div_maxdiv(sclk); + + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) + return sclk_div_getdiv(hw, rate, *prate, maxdiv); + + /* + * The maximum divider we can use without overflowing + * unsigned long in rate * i below + */ + maxdiv = min(ULONG_MAX / rate, maxdiv); + + for (i = 2; i <= maxdiv; i++) { + /* + * It's the most ideal case if the requested rate can be + * divided from parent clock without needing to change + * parent rate, so return the divider immediately. + */ + if (rate * i == *prate) + return i; + + parent_now = clk_hw_round_rate(parent, rate * i); + now = DIV_ROUND_UP_ULL((u64)parent_now, i); + + if (abs(rate - now) < abs(rate - best)) { + bestdiv = i; + best = now; + best_parent = parent_now; + } + } + + if (!bestdiv) + bestdiv = sclk_div_maxdiv(sclk); + else + *prate = best_parent; + + return bestdiv; +} + +static long sclk_div_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + int div; + + div = sclk_div_bestdiv(hw, rate, prate, sclk); + + return DIV_ROUND_UP_ULL((u64)*prate, div); +} + +static void sclk_apply_ratio(struct clk_regmap *clk, + struct meson_sclk_div_data *sclk) +{ + unsigned int hi = DIV_ROUND_CLOSEST(sclk->cached_div * + sclk->cached_duty.num, + sclk->cached_duty.den); + + if (hi) + hi -= 1; + + meson_parm_write(clk->map, &sclk->hi, hi); +} + +static int sclk_div_set_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + if (MESON_PARM_APPLICABLE(&sclk->hi)) { + memcpy(&sclk->cached_duty, duty, sizeof(*duty)); + sclk_apply_ratio(clk, sclk); + } + + return 0; +} + +static int sclk_div_get_duty_cycle(struct clk_hw *hw, + struct clk_duty *duty) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + int hi; + + if (!MESON_PARM_APPLICABLE(&sclk->hi)) { + duty->num = 1; + duty->den = 2; + return 0; + } + + hi = meson_parm_read(clk->map, &sclk->hi); + duty->num = hi + 1; + duty->den = sclk->cached_div; + return 0; +} + +static void sclk_apply_divider(struct clk_regmap *clk, + struct meson_sclk_div_data *sclk) +{ + if (MESON_PARM_APPLICABLE(&sclk->hi)) + sclk_apply_ratio(clk, sclk); + + meson_parm_write(clk->map, &sclk->div, sclk->cached_div - 1); +} + +static int sclk_div_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + unsigned long maxdiv = sclk_div_maxdiv(sclk); + + sclk->cached_div = sclk_div_getdiv(hw, rate, prate, maxdiv); + + if (clk_hw_is_enabled(hw)) + sclk_apply_divider(clk, sclk); + + return 0; +} + +static unsigned long sclk_div_recalc_rate(struct clk_hw *hw, + unsigned long prate) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + return DIV_ROUND_UP_ULL((u64)prate, sclk->cached_div); +} + +static int sclk_div_enable(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + sclk_apply_divider(clk, sclk); + + return 0; +} + +static void sclk_div_disable(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + meson_parm_write(clk->map, &sclk->div, 0); +} + +static int sclk_div_is_enabled(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + + if (meson_parm_read(clk->map, &sclk->div)) + return 1; + + return 0; +} + +static void sclk_div_init(struct clk_hw *hw) +{ + struct clk_regmap *clk = to_clk_regmap(hw); + struct meson_sclk_div_data *sclk = meson_sclk_div_data(clk); + unsigned int val; + + val = meson_parm_read(clk->map, &sclk->div); + + /* if the divider is initially disabled, assume max */ + if (!val) + sclk->cached_div = sclk_div_maxdiv(sclk); + else + sclk->cached_div = val + 1; + + sclk_div_get_duty_cycle(hw, &sclk->cached_duty); +} + +const struct clk_ops meson_sclk_div_ops = { + .recalc_rate = sclk_div_recalc_rate, + .round_rate = sclk_div_round_rate, + .set_rate = sclk_div_set_rate, + .enable = sclk_div_enable, + .disable = sclk_div_disable, + .is_enabled = sclk_div_is_enabled, + .get_duty_cycle = sclk_div_get_duty_cycle, + .set_duty_cycle = sclk_div_set_duty_cycle, + .init = sclk_div_init, +}; +EXPORT_SYMBOL_GPL(meson_sclk_div_ops);