From patchwork Sun Sep 27 14:57:08 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 7273321 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 [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AB4C0BEEA4 for ; Sun, 27 Sep 2015 14:59:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C8BFE20895 for ; Sun, 27 Sep 2015 14:59:37 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CB5D02088F for ; Sun, 27 Sep 2015 14:59:36 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZgDOS-0005Lj-Pv; Sun, 27 Sep 2015 14:57:36 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZgDOP-0005GO-Jv for linux-arm-kernel@lists.infradead.org; Sun, 27 Sep 2015 14:57:34 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 2AA7BA0BA8; Sun, 27 Sep 2015 14:57:12 +0000 (UTC) Received: from shalem.localdomain.com (vpn1-4-52.ams2.redhat.com [10.36.4.52]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t8REv9p3005765; Sun, 27 Sep 2015 10:57:10 -0400 From: Hans de Goede To: Wolfram Sang , Thomas Petazzoni Subject: [PATCH] i2c: mv64xxx: The n clockdiv factor is 0 based on sunxi SoCs Date: Sun, 27 Sep 2015 16:57:08 +0200 Message-Id: <1443365828-8956-1-git-send-email-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150927_075733_702911_EDE72EC5 X-CRM114-Status: GOOD ( 14.98 ) X-Spam-Score: -6.9 (------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hans de Goede , Maxime Ripard , linux-sunxi@googlegroups.com, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 According to the datasheets to n factor for dividing the tclk is 2 to the power n on Allwinner SoCs, not 2 to the power n + 1 as it is on other mv64xxx implementations. I've contacted Allwinner about this and they have confirmed that the datasheet is correct. This commit fixes the clk-divider calculations for Allwinner SoCs accordingly. Signed-off-by: Hans de Goede Acked-by: Maxime Ripard Tested-by: Olliver Schinagl --- drivers/i2c/busses/i2c-mv64xxx.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index 30059c1..e75cf6d 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -146,6 +146,8 @@ struct mv64xxx_i2c_data { bool errata_delay; struct reset_control *rstc; bool irq_clear_inverted; + /* Clk div is 2 to the power n, not 2 to the power n + 1 */ + bool clk_n_base_0; }; static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = { @@ -759,25 +761,29 @@ MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table); #ifdef CONFIG_OF #ifdef CONFIG_HAVE_CLK static int -mv64xxx_calc_freq(const int tclk, const int n, const int m) +mv64xxx_calc_freq(struct mv64xxx_i2c_data *drv_data, + const int tclk, const int n, const int m) { - return tclk / (10 * (m + 1) * (2 << n)); + if (drv_data->clk_n_base_0) + return tclk / (10 * (m + 1) * (1 << n)); + else + return tclk / (10 * (m + 1) * (2 << n)); } static bool -mv64xxx_find_baud_factors(const u32 req_freq, const u32 tclk, u32 *best_n, - u32 *best_m) +mv64xxx_find_baud_factors(struct mv64xxx_i2c_data *drv_data, + const u32 req_freq, const u32 tclk) { int freq, delta, best_delta = INT_MAX; int m, n; for (n = 0; n <= 7; n++) for (m = 0; m <= 15; m++) { - freq = mv64xxx_calc_freq(tclk, n, m); + freq = mv64xxx_calc_freq(drv_data, tclk, n, m); delta = req_freq - freq; if (delta >= 0 && delta < best_delta) { - *best_m = m; - *best_n = n; + drv_data->freq_m = m; + drv_data->freq_n = n; best_delta = delta; } if (best_delta == 0) @@ -815,8 +821,11 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data, if (of_property_read_u32(np, "clock-frequency", &bus_freq)) bus_freq = 100000; /* 100kHz by default */ - if (!mv64xxx_find_baud_factors(bus_freq, tclk, - &drv_data->freq_n, &drv_data->freq_m)) { + if (of_device_is_compatible(np, "allwinner,sun4i-a10-i2c") || + of_device_is_compatible(np, "allwinner,sun6i-a31-i2c")) + drv_data->clk_n_base_0 = true; + + if (!mv64xxx_find_baud_factors(drv_data, bus_freq, tclk)) { rc = -EINVAL; goto out; }