From: Richard Zhao <richard.zhao@linaro.org> To: Mike Turquette <mturquette@linaro.org> Cc: Russell King <linux@arm.linux.org.uk>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-dev@lists.linaro.org, patches@linaro.org, Mike Turquette <mturquette@ti.com>, Jeremy Kerr <jeremy.kerr@canonical.com>, Thomas Gleixner <tglx@linutronix.de>, Arnd Bergman <arnd.bergmann@linaro.org>, Paul Walmsley <paul@pwsan.com>, Shawn Guo <shawn.guo@freescale.com>, Sascha Hauer <s.hauer@pengutronix.de>, Jamie Iles <jamie@jamieiles.com>, Saravana Kannan <skannan@codeaurora.org>, Magnus Damm <magnus.damm@gmail.com>, Mark Brown <broonie@opensource.wolfsonmicro.com>, Linus Walleij <linus.walleij@stericsson.com>, Stephen Boyd <sboyd@codeaurora.org>, Amit Kucheria <amit.kucheria@linaro.org>, Deepak Saxena <dsaxena@linaro.org>, Grant Likely <grant.likely@secretlab.ca> Subject: Re: [PATCH v7 3/3] clk: basic clock hardware types Date: Fri, 16 Mar 2012 20:25:45 +0800 [thread overview] Message-ID: <20120316122542.GA1774@richard-laptop> (raw) In-Reply-To: <1331878280-2758-4-git-send-email-mturquette@linaro.org> [...] > +static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > + unsigned long *best_parent_rate) > +{ > + struct clk_divider *divider = to_clk_divider(hw); > + int i, bestdiv = 0; > + unsigned long parent_rate, best = 0, now, maxdiv; > + > + if (!rate) > + rate = 1; > + > + maxdiv = (1 << divider->width); > + > + if (divider->flags & CLK_DIVIDER_ONE_BASED) > + maxdiv--; > + > + if (!best_parent_rate) { > + parent_rate = __clk_get_rate(__clk_get_parent(hw->clk)); > + bestdiv = DIV_ROUND_UP(parent_rate, rate); > + bestdiv = bestdiv == 0 ? 1 : bestdiv; > + bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; > + return bestdiv; > + } > + > + /* > + * The maximum divider we can use without overflowing > + * unsigned long in rate * i below > + */ > + maxdiv = min(ULONG_MAX / rate, maxdiv); > + > + for (i = 1; i <= maxdiv; i++) { > + parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), > + MULT_ROUND_UP(rate, i)); > + now = parent_rate / i; > + if (now <= rate && now > best) { > + bestdiv = i; > + best = now; > + *best_parent_rate = parent_rate; Better add if (now == rate) break; There may be more than one hit for (now == rate). We'd better select smallest div, thus smallest parent_rate. It's the same comment for v6, but not show stopper. Thanks Richard > + } > + } > + > + if (!bestdiv) { > + bestdiv = (1 << divider->width); > + if (divider->flags & CLK_DIVIDER_ONE_BASED) > + bestdiv--; > + *best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1); > + } > + > + return bestdiv; > +}
WARNING: multiple messages have this Message-ID (diff)
From: richard.zhao@linaro.org (Richard Zhao) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v7 3/3] clk: basic clock hardware types Date: Fri, 16 Mar 2012 20:25:45 +0800 [thread overview] Message-ID: <20120316122542.GA1774@richard-laptop> (raw) In-Reply-To: <1331878280-2758-4-git-send-email-mturquette@linaro.org> [...] > +static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > + unsigned long *best_parent_rate) > +{ > + struct clk_divider *divider = to_clk_divider(hw); > + int i, bestdiv = 0; > + unsigned long parent_rate, best = 0, now, maxdiv; > + > + if (!rate) > + rate = 1; > + > + maxdiv = (1 << divider->width); > + > + if (divider->flags & CLK_DIVIDER_ONE_BASED) > + maxdiv--; > + > + if (!best_parent_rate) { > + parent_rate = __clk_get_rate(__clk_get_parent(hw->clk)); > + bestdiv = DIV_ROUND_UP(parent_rate, rate); > + bestdiv = bestdiv == 0 ? 1 : bestdiv; > + bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; > + return bestdiv; > + } > + > + /* > + * The maximum divider we can use without overflowing > + * unsigned long in rate * i below > + */ > + maxdiv = min(ULONG_MAX / rate, maxdiv); > + > + for (i = 1; i <= maxdiv; i++) { > + parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), > + MULT_ROUND_UP(rate, i)); > + now = parent_rate / i; > + if (now <= rate && now > best) { > + bestdiv = i; > + best = now; > + *best_parent_rate = parent_rate; Better add if (now == rate) break; There may be more than one hit for (now == rate). We'd better select smallest div, thus smallest parent_rate. It's the same comment for v6, but not show stopper. Thanks Richard > + } > + } > + > + if (!bestdiv) { > + bestdiv = (1 << divider->width); > + if (divider->flags & CLK_DIVIDER_ONE_BASED) > + bestdiv--; > + *best_parent_rate = __clk_round_rate(__clk_get_parent(hw->clk), 1); > + } > + > + return bestdiv; > +}
next prev parent reply other threads:[~2012-03-16 12:26 UTC|newest] Thread overview: 242+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-03-16 6:11 [PATCH v7 0/3] common clk framework Mike Turquette 2012-03-16 6:11 ` Mike Turquette 2012-03-16 6:11 ` [PATCH v7 1/3] Documentation: common clk API Mike Turquette 2012-03-16 6:11 ` Mike Turquette 2012-03-16 8:25 ` Linus Walleij 2012-03-16 8:25 ` Linus Walleij 2012-03-16 10:29 ` Thomas Gleixner 2012-03-16 10:29 ` Thomas Gleixner 2012-03-16 11:14 ` Amit Kucheria 2012-03-16 11:14 ` Amit Kucheria 2012-03-16 12:18 ` Arnd Bergmann 2012-03-16 12:18 ` Arnd Bergmann 2012-03-16 20:57 ` Arnd Bergmann 2012-03-16 20:57 ` Arnd Bergmann 2012-03-16 21:40 ` Turquette, Mike 2012-03-16 21:40 ` Turquette, Mike 2012-03-16 21:50 ` Nicolas Pitre 2012-03-16 21:50 ` Nicolas Pitre 2012-03-16 22:21 ` Paul Walmsley 2012-03-16 22:21 ` Paul Walmsley 2012-03-16 22:21 ` Paul Walmsley 2012-03-16 22:33 ` Turquette, Mike 2012-03-16 22:33 ` Turquette, Mike 2012-03-17 9:05 ` Arnd Bergmann 2012-03-17 9:05 ` Arnd Bergmann 2012-03-17 9:05 ` Arnd Bergmann 2012-03-17 18:02 ` Turquette, Mike 2012-03-17 18:02 ` Turquette, Mike 2012-03-17 18:02 ` Turquette, Mike 2012-03-17 18:33 ` Arnd Bergmann 2012-03-17 18:33 ` Arnd Bergmann 2012-03-17 18:33 ` Arnd Bergmann 2012-03-17 20:29 ` Sascha Hauer 2012-03-17 20:29 ` Sascha Hauer 2012-03-17 20:29 ` Sascha Hauer 2012-03-17 21:13 ` Arnd Bergmann 2012-03-17 21:13 ` Arnd Bergmann 2012-03-17 21:13 ` Arnd Bergmann 2012-03-20 23:40 ` Paul Walmsley 2012-03-20 23:40 ` Paul Walmsley 2012-03-21 8:59 ` Arnd Bergmann 2012-03-21 8:59 ` Arnd Bergmann 2012-03-16 23:47 ` Sascha Hauer 2012-03-16 23:47 ` Sascha Hauer 2012-03-16 23:47 ` Sascha Hauer 2012-03-17 0:54 ` Rob Herring 2012-03-17 0:54 ` Rob Herring 2012-03-17 0:54 ` Rob Herring 2012-03-17 3:38 ` Saravana Kannan 2012-03-17 3:38 ` Saravana Kannan 2012-03-17 3:38 ` Saravana Kannan 2012-03-20 23:31 ` Paul Walmsley 2012-03-20 23:31 ` Paul Walmsley 2012-03-20 23:31 ` Paul Walmsley 2012-03-21 3:15 ` Nicolas Pitre 2012-03-21 3:15 ` Nicolas Pitre 2012-03-21 3:15 ` Nicolas Pitre 2012-03-21 3:26 ` Saravana Kannan 2012-03-21 3:26 ` Saravana Kannan 2012-03-21 3:26 ` Saravana Kannan 2012-03-21 7:44 ` Paul Walmsley 2012-03-21 7:44 ` Paul Walmsley 2012-03-21 7:44 ` Paul Walmsley 2012-03-21 9:10 ` Sascha Hauer 2012-03-21 9:10 ` Sascha Hauer 2012-03-21 9:10 ` Sascha Hauer 2012-03-21 18:38 ` Saravana Kannan 2012-03-21 18:38 ` Saravana Kannan 2012-03-21 18:38 ` Saravana Kannan 2012-03-21 19:07 ` Mark Brown 2012-03-21 19:07 ` Mark Brown 2012-03-21 19:07 ` Mark Brown 2012-03-21 19:33 ` Tony Lindgren 2012-03-21 19:33 ` Tony Lindgren 2012-03-21 19:33 ` Tony Lindgren 2012-03-21 19:41 ` Saravana Kannan 2012-03-21 19:41 ` Saravana Kannan 2012-03-21 19:41 ` Saravana Kannan 2012-03-21 19:56 ` Mark Brown 2012-03-21 19:56 ` Mark Brown 2012-03-21 19:56 ` Mark Brown 2012-03-21 20:04 ` Saravana Kannan 2012-03-21 20:04 ` Saravana Kannan 2012-03-21 20:04 ` Saravana Kannan 2012-03-21 20:10 ` Mark Brown 2012-03-21 20:10 ` Mark Brown 2012-03-21 20:10 ` Mark Brown 2012-03-22 0:42 ` Russell King - ARM Linux 2012-03-22 0:42 ` Russell King - ARM Linux 2012-03-22 0:42 ` Russell King - ARM Linux 2012-03-21 7:30 ` Paul Walmsley 2012-03-21 7:30 ` Paul Walmsley 2012-03-21 7:30 ` Paul Walmsley 2012-03-21 13:23 ` Nicolas Pitre 2012-03-21 13:23 ` Nicolas Pitre 2012-03-21 13:23 ` Nicolas Pitre 2012-03-16 6:11 ` [PATCH v7 2/3] clk: introduce the common clock framework Mike Turquette 2012-03-16 6:11 ` Mike Turquette 2012-03-17 3:28 ` Saravana Kannan 2012-03-17 3:28 ` Saravana Kannan 2012-03-19 18:56 ` Turquette, Mike 2012-03-19 18:56 ` Turquette, Mike 2012-03-19 19:13 ` Saravana Kannan 2012-03-19 19:13 ` Saravana Kannan 2012-03-19 19:33 ` Turquette, Mike 2012-03-19 19:33 ` Turquette, Mike 2012-03-19 19:49 ` Saravana Kannan 2012-03-19 19:49 ` Saravana Kannan 2012-03-20 3:38 ` [PATCH 1/2] clk: Fix error handling in fixed clock hardware type register fn Saravana Kannan 2012-03-20 3:38 ` Saravana Kannan 2012-03-20 3:38 ` [PATCH 2/2] clk: Move init fields from clk to clk_hw Saravana Kannan 2012-03-20 3:38 ` Saravana Kannan 2012-03-20 7:20 ` Shawn Guo 2012-03-20 7:20 ` Shawn Guo 2012-03-20 7:54 ` Saravana Kannan 2012-03-20 7:54 ` Saravana Kannan 2012-03-20 7:54 ` Saravana Kannan 2012-03-20 8:13 ` Shawn Guo 2012-03-20 8:13 ` Shawn Guo 2012-03-20 9:40 ` Sascha Hauer 2012-03-20 9:40 ` Sascha Hauer 2012-03-20 10:17 ` Saravana Kannan 2012-03-20 10:17 ` Saravana Kannan 2012-03-20 10:17 ` Saravana Kannan 2012-03-20 18:14 ` Sascha Hauer 2012-03-20 18:14 ` Sascha Hauer 2012-03-20 20:14 ` Saravana Kannan 2012-03-20 20:14 ` Saravana Kannan 2012-03-20 22:40 ` Sascha Hauer 2012-03-20 22:40 ` Sascha Hauer 2012-03-22 3:23 ` Shawn Guo 2012-03-22 3:23 ` Shawn Guo 2012-03-20 14:18 ` Shawn Guo 2012-03-20 14:18 ` Shawn Guo 2012-03-20 18:10 ` Sascha Hauer 2012-03-20 18:10 ` Sascha Hauer 2012-03-20 20:06 ` Saravana Kannan 2012-03-20 20:06 ` Saravana Kannan 2012-03-20 23:12 ` Sascha Hauer 2012-03-20 23:12 ` Sascha Hauer 2012-03-21 1:47 ` Turquette, Mike 2012-03-21 1:47 ` Turquette, Mike 2012-03-21 3:01 ` Saravana Kannan 2012-03-21 3:01 ` Saravana Kannan 2012-03-27 4:35 ` Saravana Kannan 2012-03-27 4:35 ` Saravana Kannan 2012-03-27 18:49 ` Turquette, Mike 2012-03-27 18:49 ` Turquette, Mike 2012-03-27 22:27 ` Saravana Kannan 2012-03-27 22:27 ` Saravana Kannan 2012-04-06 1:30 ` Saravana Kannan 2012-04-06 1:30 ` Saravana Kannan 2012-04-11 17:59 ` Turquette, Mike 2012-04-11 17:59 ` Turquette, Mike 2012-04-11 19:57 ` Saravana Kannan 2012-04-11 19:57 ` Saravana Kannan 2012-04-11 19:57 ` Saravana Kannan 2012-04-11 20:17 ` Turquette, Mike 2012-04-11 20:17 ` Turquette, Mike 2012-04-11 20:21 ` Saravana Kannan 2012-04-11 20:21 ` Saravana Kannan 2012-04-11 20:21 ` Saravana Kannan 2012-03-20 23:47 ` Paul Walmsley 2012-03-20 23:47 ` Paul Walmsley 2012-03-21 9:16 ` Sascha Hauer 2012-03-21 9:16 ` Sascha Hauer 2012-03-20 7:19 ` [PATCH 1/2] clk: Fix error handling in fixed clock hardware type register fn Sascha Hauer 2012-03-20 7:19 ` Sascha Hauer 2012-03-20 7:46 ` Saravana Kannan 2012-03-20 7:46 ` Saravana Kannan 2012-03-20 7:46 ` Saravana Kannan 2012-03-21 0:13 ` Turquette, Mike 2012-03-21 0:13 ` Turquette, Mike 2012-03-21 2:32 ` Saravana Kannan 2012-03-21 2:32 ` Saravana Kannan 2012-03-21 5:45 ` Turquette, Mike 2012-03-21 5:45 ` Turquette, Mike 2012-03-21 6:33 ` Saravana Kannan 2012-03-21 6:33 ` Saravana Kannan 2012-03-21 6:33 ` Saravana Kannan 2012-03-21 9:07 ` Russell King - ARM Linux 2012-03-21 9:07 ` Russell King - ARM Linux 2012-03-21 19:56 ` Turquette, Mike 2012-03-21 19:56 ` Turquette, Mike 2012-03-18 13:46 ` [PATCH v7 2/3] clk: introduce the common clock framework Shawn Guo 2012-03-18 13:46 ` Shawn Guo 2012-03-19 18:58 ` Turquette, Mike 2012-03-19 18:58 ` Turquette, Mike 2012-03-18 14:07 ` Shawn Guo 2012-03-18 14:07 ` Shawn Guo 2012-03-19 19:00 ` Turquette, Mike 2012-03-19 19:00 ` Turquette, Mike 2012-03-19 11:22 ` Rajendra Nayak 2012-03-19 11:22 ` Rajendra Nayak 2012-03-19 11:28 ` Sascha Hauer 2012-03-19 11:28 ` Sascha Hauer 2012-03-19 19:09 ` Turquette, Mike 2012-03-19 19:09 ` Turquette, Mike 2012-03-19 19:53 ` Turquette, Mike 2012-03-19 19:53 ` Turquette, Mike 2012-03-20 14:02 ` Shawn Guo 2012-03-20 14:02 ` Shawn Guo 2012-03-20 17:46 ` Saravana Kannan 2012-03-20 17:46 ` Saravana Kannan 2012-03-20 23:53 ` Turquette, Mike 2012-03-20 23:53 ` Turquette, Mike 2012-03-21 3:10 ` Saravana Kannan 2012-03-21 3:10 ` Saravana Kannan 2012-03-23 21:33 ` Saravana Kannan 2012-03-23 21:33 ` Saravana Kannan 2012-03-23 21:39 ` Turquette, Mike 2012-03-23 21:39 ` Turquette, Mike 2012-03-23 21:51 ` Saravana Kannan 2012-03-23 21:51 ` Saravana Kannan 2012-03-23 22:12 ` Saravana Kannan 2012-03-23 22:12 ` Saravana Kannan 2012-03-23 22:32 ` Turquette, Mike 2012-03-23 22:32 ` Turquette, Mike 2012-03-23 23:04 ` Saravana Kannan 2012-03-23 23:04 ` Saravana Kannan 2012-03-23 23:28 ` Turquette, Mike 2012-03-23 23:28 ` Turquette, Mike 2012-03-28 3:06 ` Saravana Kannan 2012-03-28 3:06 ` Saravana Kannan 2012-03-28 17:08 ` Turquette, Mike 2012-03-28 17:08 ` Turquette, Mike 2012-03-28 22:25 ` Saravana Kannan 2012-03-28 22:25 ` Saravana Kannan 2012-03-28 23:49 ` Turquette, Mike 2012-03-28 23:49 ` Turquette, Mike 2012-03-20 23:46 ` Turquette, Mike 2012-03-20 23:46 ` Turquette, Mike 2012-03-21 5:46 ` Shawn Guo 2012-03-21 5:46 ` Shawn Guo 2012-03-16 6:11 ` [PATCH v7 3/3] clk: basic clock hardware types Mike Turquette 2012-03-16 6:11 ` Mike Turquette 2012-03-16 12:25 ` Richard Zhao [this message] 2012-03-16 12:25 ` Richard Zhao 2012-03-16 16:51 ` Turquette, Mike 2012-03-16 16:51 ` Turquette, Mike 2012-03-16 10:57 ` [PATCH v7 0/3] common clk framework Sascha Hauer 2012-03-16 10:57 ` Sascha Hauer
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