From patchwork Wed Feb 26 00:15:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Elder X-Patchwork-Id: 3720181 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 24E0BBF13A for ; Wed, 26 Feb 2014 01:30:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2523A201DD for ; Wed, 26 Feb 2014 01:30:27 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (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 ED6B6201CD for ; Wed, 26 Feb 2014 01:30:25 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WISCW-0004sw-S5; Wed, 26 Feb 2014 00:18:18 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WISBv-0004O8-KY; Wed, 26 Feb 2014 00:17:39 +0000 Received: from mail-ig0-f171.google.com ([209.85.213.171]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WISAf-0004DK-NA for linux-arm-kernel@lists.infradead.org; Wed, 26 Feb 2014 00:16:34 +0000 Received: by mail-ig0-f171.google.com with SMTP id l13so3700688iga.4 for ; Tue, 25 Feb 2014 16:16:00 -0800 (PST) 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=SF/5+2Y7GcDXZy9XqrVBXcz6mXOosK1ovJ8xbLk2R3Y=; b=UoP5vQJ3y0nhsEZYnVHfYbYaqTUOg+6xzvr5sAhXrmBCFVZsFD+4ybPTL80BiU11CE A+Ot3ZoQzCSeIPUxYk4NmpoljgphjfMWid5u3rGYsSXGLMtFpkw4tpwsuzIiPzRpI/s7 959uVes8eO60/rUU3NY+htysMHtFbI1GZCZSMnU+3w91GK7W1QUQqLaPrQaseIrB2F8O OyW9ZiWm04aCgwVaYzWU+ppXbtHg9k9kdtx4AKsGi2hBnSNkuMciVb72dIu91iOmDlcE 6HGhEUIRJSoxhBGR5ZyFHSn6il/Oy5Iox8ooD0Tet8yehD+VJ6VIPsSkUR47LhCfWCHB dhtg== X-Gm-Message-State: ALoCoQknM3DSeSD1WmEdm8ndsklWTzSuu4b9KwNHYYPHsl+lxpk63Lp9Z3MYeQIR7IjSi7c7EgwE X-Received: by 10.50.50.241 with SMTP id f17mr7610336igo.23.1393373760502; Tue, 25 Feb 2014 16:16:00 -0800 (PST) Received: from localhost.localdomain (c-71-195-31-37.hsd1.mn.comcast.net. [71.195.31.37]) by mx.google.com with ESMTPSA id om7sm91459igb.10.2014.02.25.16.15.59 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 25 Feb 2014 16:16:00 -0800 (PST) From: Alex Elder To: mturquette@linaro.org, mporter@linaro.org, bcm@fixthebug.org, galak@codeaurora.org, ijc+devicetree@hellion.org.uk, mark.rutland@arm.com, pawel.moll@arm.com, robh+dt@kernel.org Subject: [PATCH v2 07/12] clk: bcm281xx: add clock hysteresis support Date: Tue, 25 Feb 2014 18:15:47 -0600 Message-Id: <1393373752-30875-8-git-send-email-elder@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1393373752-30875-1-git-send-email-elder@linaro.org> References: <1393373752-30875-1-git-send-email-elder@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140225_191621_899209_7A36E4B3 X-CRM114-Status: GOOD ( 18.49 ) X-Spam-Score: 0.5 (/) Cc: devicetree@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 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=-1.1 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=no 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 Add support for clock gate hysteresis control. For now, if it's defined for a clock, it's enabled. Signed-off-by: Alex Elder --- drivers/clk/bcm/clk-kona-setup.c | 30 ++++++++++++++++++++++++++++++ drivers/clk/bcm/clk-kona.c | 33 +++++++++++++++++++++++++++++++++ drivers/clk/bcm/clk-kona.h | 19 +++++++++++++++++++ 3 files changed, 82 insertions(+) diff --git a/drivers/clk/bcm/clk-kona-setup.c b/drivers/clk/bcm/clk-kona-setup.c index 5a49deb..757de19 100644 --- a/drivers/clk/bcm/clk-kona-setup.c +++ b/drivers/clk/bcm/clk-kona-setup.c @@ -81,6 +81,7 @@ static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk) struct peri_clk_data *peri; struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; + struct bcm_clk_hyst *hyst; struct bcm_clk_div *div; struct bcm_clk_sel *sel; struct bcm_clk_trig *trig; @@ -106,12 +107,25 @@ static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk) } gate = &peri->gate; + hyst = &peri->hyst; if (gate_exists(gate)) { if (gate->offset > limit) { pr_err("%s: bad gate offset for %s (%u > %u)\n", __func__, name, gate->offset, limit); return false; } + + if (hyst_exists(hyst)) { + if (hyst->offset > limit) { + pr_err("%s: bad hysteresis offset for %s " + "(%u > %u)\n", __func__, + name, hyst->offset, limit); + return false; + } + } + } else if (hyst_exists(hyst)) { + pr_err("%s: hysteresis but no gate for %s\n", __func__, name); + return false; } div = &peri->div; @@ -261,6 +275,17 @@ static bool gate_valid(struct bcm_clk_gate *gate, const char *field_name, return true; } +static bool hyst_valid(struct bcm_clk_hyst *hyst, const char *clock_name) +{ + if (!bit_posn_valid(hyst->en_bit, "hysteresis enable", clock_name)) + return false; + + if (!bit_posn_valid(hyst->val_bit, "hysteresis value", clock_name)) + return false; + + return true; +} + /* * A selector bitfield must be valid. Its parent_sel array must * also be reasonable for the field. @@ -378,6 +403,7 @@ peri_clk_data_valid(struct kona_clk *bcm_clk) struct peri_clk_data *peri; struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; + struct bcm_clk_hyst *hyst; struct bcm_clk_sel *sel; struct bcm_clk_div *div; struct bcm_clk_div *pre_div; @@ -405,6 +431,10 @@ peri_clk_data_valid(struct kona_clk *bcm_clk) if (gate_exists(gate) && !gate_valid(gate, "gate", name)) return false; + hyst = &peri->hyst; + if (hyst_exists(hyst) && !hyst_valid(hyst, name)) + return false; + sel = &peri->sel; if (selector_exists(sel)) { if (!sel_valid(sel, "selector", name)) diff --git a/drivers/clk/bcm/clk-kona.c b/drivers/clk/bcm/clk-kona.c index bf9661c..64b6361 100644 --- a/drivers/clk/bcm/clk-kona.c +++ b/drivers/clk/bcm/clk-kona.c @@ -527,6 +527,35 @@ static int clk_gate(struct ccu_data *ccu, const char *name, return -EIO; } +/* Hysteresis operations */ + +/* + * If a clock gate requires a turn-off delay it will have + * "hysteresis" register bits defined. The first, if set, enables + * the delay; and if enabled, the second bit determines whether the + * delay is "low" or "high" (1 means high). For now, if it's + * defined for a clock, we set it. + */ +static bool hyst_init(struct ccu_data *ccu, struct bcm_clk_hyst *hyst) +{ + u32 offset; + u32 reg_val; + u32 mask; + + if (!hyst_exists(hyst)) + return true; + + offset = hyst->offset; + mask = (u32)1 << hyst->en_bit; + mask |= (u32)1 << hyst->val_bit; + + reg_val = __ccu_read(ccu, offset); + reg_val |= mask; + __ccu_write(ccu, offset, reg_val); + + return true; +} + /* Trigger operations */ /* @@ -1129,6 +1158,10 @@ static bool __peri_clk_init(struct kona_clk *bcm_clk) pr_err("%s: error initializing gate for %s\n", __func__, name); return false; } + if (!hyst_init(ccu, &peri->hyst)) { + pr_err("%s: error initializing hyst for %s\n", __func__, name); + return false; + } if (!div_init(ccu, &peri->gate, &peri->div, &peri->trig)) { pr_err("%s: error initializing divider for %s\n", __func__, name); diff --git a/drivers/clk/bcm/clk-kona.h b/drivers/clk/bcm/clk-kona.h index c390ca4..c6285d2 100644 --- a/drivers/clk/bcm/clk-kona.h +++ b/drivers/clk/bcm/clk-kona.h @@ -60,6 +60,8 @@ #define gate_flip_enabled(gate) FLAG_FLIP(gate, GATE, ENABLED) +#define hyst_exists(hyst) ((hyst)->offset != 0) + #define divider_exists(div) FLAG_TEST(div, DIV, EXISTS) #define divider_is_fixed(div) FLAG_TEST(div, DIV, FIXED) #define divider_has_fraction(div) (!divider_is_fixed(div) && \ @@ -205,6 +207,22 @@ struct bcm_clk_gate { .flags = FLAG(GATE, HW)|FLAG(GATE, EXISTS), \ } +/* Gate hysteresis for clocks */ +struct bcm_clk_hyst { + u32 offset; /* hyst register offset (normally CLKGATE) */ + u32 en_bit; /* bit used to enable hysteresis */ + u32 val_bit; /* if enabled: 0 = low delay; 1 = high delay */ +}; + +/* Hysteresis initialization macro */ + +#define HYST(_offset, _en_bit, _val_bit) \ + { \ + .offset = (_offset), \ + .en_bit = (_en_bit), \ + .val_bit = (_val_bit), \ + } + /* * Each clock can have zero, one, or two dividers which change the * output rate of the clock. Each divider can be either fixed or @@ -372,6 +390,7 @@ struct bcm_clk_trig { struct peri_clk_data { struct bcm_clk_policy policy; struct bcm_clk_gate gate; + struct bcm_clk_hyst hyst; struct bcm_clk_trig pre_trig; struct bcm_clk_div pre_div; struct bcm_clk_trig trig;