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[209.132.180.67]) by mx.google.com with ESMTP id y11-v6si4405712pgi.121.2018.10.24.03.58.34; Wed, 24 Oct 2018 03:58:49 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727562AbeJXTZr (ORCPT + 99 others); Wed, 24 Oct 2018 15:25:47 -0400 Received: from mail-sh2.amlogic.com ([58.32.228.45]:21872 "EHLO mail-sh2.amlogic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727090AbeJXTZr (ORCPT ); Wed, 24 Oct 2018 15:25:47 -0400 Received: from [10.18.29.185] (10.18.29.185) by mail-sh2.amlogic.com (10.18.11.6) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Wed, 24 Oct 2018 18:57:50 +0800 Subject: Re: [PATCH v5 1/3] clk: meson: add emmc sub clock phase delay driver To: Jerome Brunet , Neil Armstrong CC: Yixun Lan , Kevin Hilman , Carlo Caione , Michael Turquette , Stephen Boyd , Rob Herring , Miquel Raynal , Boris Brezillon , Martin Blumenstingl , Liang Yang , Jian Hu , Qiufang Dai , Hanjie Lin , Victor Wan , , , , , References: <1539839245-13793-1-git-send-email-jianxin.pan@amlogic.com> <1539839245-13793-2-git-send-email-jianxin.pan@amlogic.com> <10a0572db79ef0cb4f345c8ba2685bea5670b1a5.camel@baylibre.com> From: Jianxin Pan Message-ID: <04c6457f-4cc1-9af5-c56e-6880d5abc40d@amlogic.com> Date: Wed, 24 Oct 2018 18:57:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <10a0572db79ef0cb4f345c8ba2685bea5670b1a5.camel@baylibre.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.18.29.185] X-ClientProxiedBy: mail-sh2.amlogic.com (10.18.11.6) To mail-sh2.amlogic.com (10.18.11.6) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/10/24 16:58, Jerome Brunet wrote: > On Thu, 2018-10-18 at 13:07 +0800, Jianxin Pan wrote: >> From: Yixun Lan [...] >> >> --- /dev/null >> +++ b/drivers/clk/meson/clk-phase-delay.c >> @@ -0,0 +1,79 @@ >> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT) >> +/* >> + * Amlogic Meson MMC Sub Clock Controller Driver >> + * >> + * Copyright (c) 2017 Baylibre SAS. >> + * Author: Jerome Brunet >> + * >> + * Copyright (c) 2018 Amlogic, inc. >> + * Author: Yixun Lan >> + */ >> + >> +#include >> +#include "clkc.h" >> + >> +static int meson_clk_phase_delay_get_phase(struct clk_hw *hw) >> +{ >> + struct clk_regmap *clk = to_clk_regmap(hw); >> + struct meson_clk_phase_delay_data *ph = >> + meson_clk_get_phase_delay_data(clk); >> + unsigned long period_ps, p, d; >> + int degrees; >> + u32 val; >> + >> + regmap_read(clk->map, ph->phase.reg_off, &val); >> + p = PARM_GET(ph->phase.width, ph->phase.shift, val); > > there is an helper for this: meson_parm_read() OK. I will use meson_parm_read instead. Thanks for your review. The result of regmap_read is shared by two PARM_GETs: phase and delay. There will be one more register read when change to meson_parm_read, but I don't think it matters. > >> + degrees = p * 360 / (1 << (ph->phase.width)); >> + >> + period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000, >> + clk_hw_get_rate(hw)); >> + >> + d = PARM_GET(ph->delay.width, ph->delay.shift, val); >> + degrees += d * ph->delay_step_ps * 360 / period_ps; >> + degrees %= 360; >> + >> + return degrees; >> +} >> + >> +static void meson_clk_apply_phase_delay(struct clk_regmap *clk, >> + unsigned int phase, >> + unsigned int delay) > > This helper function is a bit overkill. > simply call meson_parm_write() twice in meson_clk_phase_delay_set_phase(). OK. I will use meson_parm_write() instead. With meson_parm_write(), there will be one more register read and write > >> +{ >> + struct meson_clk_phase_delay_data *ph = clk->data; >> + u32 val; >> + >> + regmap_read(clk->map, ph->delay.reg_off, &val); >> + val = PARM_SET(ph->phase.width, ph->phase.shift, val, phase); >> + val = PARM_SET(ph->delay.width, ph->delay.shift, val, delay); >> + regmap_write(clk->map, ph->delay.reg_off, val); >> +} >> + >> +static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees) >> +{ >> + struct clk_regmap *clk = to_clk_regmap(hw); >> + struct meson_clk_phase_delay_data *ph = >> + meson_clk_get_phase_delay_data(clk); >> + unsigned long period_ps, d = 0, r; >> + u64 p; >> + >> + p = degrees % 360; >> + period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000, >> + clk_hw_get_rate(hw)); >> + >> + /* First compute the phase index (p), the remainder (r) is the >> + * part we'll try to acheive using the delays (d). >> + */ >> + r = do_div(p, 360 / (1 << (ph->phase.width))); >> + d = DIV_ROUND_CLOSEST(r * period_ps, >> + 360 * ph->delay_step_ps); >> + d = min(d, PMASK(ph->delay.width)); >> + >> + meson_clk_apply_phase_delay(clk, p, d); >> + return 0; >> +} >> + >> +const struct clk_ops meson_clk_phase_delay_ops = { >> + .get_phase = meson_clk_phase_delay_get_phase, >> + .set_phase = meson_clk_phase_delay_set_phase, >> +}; >> +EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops); >> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h >> index 6b96d55..3309d78 100644 >> --- a/drivers/clk/meson/clkc.h >> +++ b/drivers/clk/meson/clkc.h >> @@ -105,6 +105,18 @@ struct clk_regmap _name = { \ >> }, \ >> }; >> >> +struct meson_clk_phase_delay_data { >> + struct parm phase; >> + struct parm delay; >> + unsigned int delay_step_ps; >> +}; >> + >> +static inline struct meson_clk_phase_delay_data * >> +meson_clk_get_phase_delay_data(struct clk_regmap *clk) >> +{ >> + return (struct meson_clk_phase_delay_data *)clk->data; >> +} >> + >> /* clk_ops */ >> extern const struct clk_ops meson_clk_pll_ro_ops; >> extern const struct clk_ops meson_clk_pll_ops; >> @@ -112,5 +124,6 @@ struct clk_regmap _name = { \ >> extern const struct clk_ops meson_clk_mpll_ro_ops; >> extern const struct clk_ops meson_clk_mpll_ops; >> extern const struct clk_ops meson_clk_phase_ops; >> +extern const struct clk_ops meson_clk_phase_delay_ops; >> >> #endif /* __CLKC_H */ > > > . >