From patchwork Thu Jun 6 19:09:07 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Heiko_St=C3=BCbner?= X-Patchwork-Id: 2683261 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 1C056DF23A for ; Thu, 6 Jun 2013 19:41:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754350Ab3FFTlJ (ORCPT ); Thu, 6 Jun 2013 15:41:09 -0400 Received: from gloria.sntech.de ([95.129.55.99]:40004 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753924Ab3FFTjf (ORCPT ); Thu, 6 Jun 2013 15:39:35 -0400 Received: from 146-52-32-150-dynip.superkabel.de ([146.52.32.150] helo=marty.localnet) by gloria.sntech.de with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1UkfYb-0007Ik-PS; Thu, 06 Jun 2013 21:09:09 +0200 From: Heiko =?utf-8?q?St=C3=BCbner?= To: "linux-arm-kernel@lists.infradead.org" Subject: [PATCH v2 2/8] clk: divider: add flag to limit possible dividers to even numbers Date: Thu, 6 Jun 2013 21:09:07 +0200 User-Agent: KMail/1.13.7 (Linux/3.2.0-3-686-pae; KDE/4.8.4; i686; ; ) Cc: "linux-kernel@vger.kernel.org" , Mike Turquette , Seungwon Jeon , Jaehoon Chung , Chris Ball , linux-mmc@vger.kernel.org, Grant Likely , Rob Herring , Linus Walleij , devicetree-discuss@lists.ozlabs.org, Russell King , Arnd Bergmann , Olof Johansson , Thomas Petazzoni References: <201306062107.58875.heiko@sntech.de> In-Reply-To: <201306062107.58875.heiko@sntech.de> MIME-Version: 1.0 Message-Id: <201306062109.08278.heiko@sntech.de> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org SoCs like the Rockchip Cortex-A9 ones contain divider some clocks that use the regular mechanisms for storage but allow only even dividers and 1 to be used. Therefore add a flag that lets _is_valid_div limit the valid dividers to these values. _get_maxdiv is also adapted to return even values for the CLK_DIVIDER_ONE_BASED case. Signed-off-by: Heiko Stuebner --- drivers/clk/clk-divider.c | 14 ++++++++++++-- include/linux/clk-provider.h | 2 ++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index e37c48a..adfbd0d 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -45,8 +45,16 @@ static unsigned int _get_table_maxdiv(const struct clk_div_table *table) static unsigned int _get_maxdiv(struct clk_divider *divider) { - if (divider->flags & CLK_DIVIDER_ONE_BASED) - return div_mask(divider); + if (divider->flags & CLK_DIVIDER_ONE_BASED) { + unsigned int div = div_mask(divider); + + /* decrease to even number */ + if (divider->flags & CLK_DIVIDER_EVEN) + div--; + + return div; + } + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) return 1 << div_mask(divider); if (divider->table) @@ -141,6 +149,8 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) return is_power_of_2(div); if (divider->table) return _is_valid_table_div(divider->table, div); + if (divider->flags & CLK_DIVIDER_EVEN && div != 1 && (div % 2) != 0) + return false; return true; } diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 420a187..9fdd60d 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -268,6 +268,7 @@ struct clk_div_table { * indicate the bits that get changed during a write. So for a clock with * shift 0 and width 2, setting the divider to 2 would result in a write * of (3 << 16) | (2 << 0). + * CLK_DIVIDER_EVEN - only allow even divider values */ struct clk_divider { struct clk_hw hw; @@ -283,6 +284,7 @@ struct clk_divider { #define CLK_DIVIDER_POWER_OF_TWO BIT(1) #define CLK_DIVIDER_ALLOW_ZERO BIT(2) #define CLK_DIVIDER_MASK_UPPER_HALF BIT(3) +#define CLK_DIVIDER_EVEN BIT(4) extern const struct clk_ops clk_divider_ops; struct clk *clk_register_divider(struct device *dev, const char *name,