From patchwork Fri Nov 17 18:05:37 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lucas Stach X-Patchwork-Id: 839085 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ydmHz5Ft1z9s7G for ; Sat, 18 Nov 2017 05:05:49 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161231AbdKQSFm (ORCPT ); Fri, 17 Nov 2017 13:05:42 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:49519 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753820AbdKQSFl (ORCPT ); Fri, 17 Nov 2017 13:05:41 -0500 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7] helo=dude.pengutronix.de.) by metis.ext.pengutronix.de with esmtp (Exim 4.84_2) (envelope-from ) id 1eFl1H-0000mZ-NU; Fri, 17 Nov 2017 19:05:39 +0100 From: Lucas Stach To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, kernel@pengutronix.de, patchwork-lst@pengutronix.de, Lukas Rusak , Chris Healy Subject: [PATCH 1/3] i2c: imx: use clk notifier for rate changes Date: Fri, 17 Nov 2017 19:05:37 +0100 Message-Id: <20171117180539.4984-2-l.stach@pengutronix.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171117180539.4984-1-l.stach@pengutronix.de> References: <20171117180539.4984-1-l.stach@pengutronix.de> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-i2c@vger.kernel.org Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Instead of repeatedly calling clk_get_rate for each transfer, register a clock notifier to update the cached divider value each time the clock rate actually changes. Signed-off-by: Lucas Stach --- drivers/i2c/busses/i2c-imx.c | 34 +++++++++++++++++++++++++++------- 1 file changed, 27 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 54a47b40546f..800c1f390308 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -467,15 +467,14 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx) return 0; } -static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx) +static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, + unsigned int i2c_clk_rate) { struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; - unsigned int i2c_clk_rate; unsigned int div; int i; /* Divider value calculation */ - i2c_clk_rate = clk_get_rate(i2c_imx->clk); if (i2c_imx->cur_clk == i2c_clk_rate) return; @@ -510,6 +509,24 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx) #endif } +static int i2c_imx_clk_notifier_call(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct clk_notifier_data *ndata = data; + struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk, + struct imx_i2c_struct, + clk); + + if (action & POST_RATE_CHANGE) + i2c_imx_set_clk(i2c_imx, ndata->new_rate); + + return NOTIFY_OK; +} + +static struct notifier_block i2c_imx_clk_notifier = { + .notifier_call = i2c_imx_clk_notifier_call, +}; + static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) { unsigned int temp = 0; @@ -517,8 +534,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); - i2c_imx_set_clk(i2c_imx); - imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR); /* Enable I2C controller */ imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR); @@ -1131,6 +1146,8 @@ static int i2c_imx_probe(struct platform_device *pdev) "clock-frequency", &i2c_imx->bitrate); if (ret < 0 && pdata && pdata->bitrate) i2c_imx->bitrate = pdata->bitrate; + clk_notifier_register(i2c_imx->clk, &i2c_imx_clk_notifier); + i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); /* Set up chip registers to defaults */ imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, @@ -1141,12 +1158,12 @@ static int i2c_imx_probe(struct platform_device *pdev) ret = i2c_imx_init_recovery_info(i2c_imx, pdev); /* Give it another chance if pinctrl used is not ready yet */ if (ret == -EPROBE_DEFER) - goto rpm_disable; + goto clk_notifier_unregister; /* Add I2C adapter */ ret = i2c_add_numbered_adapter(&i2c_imx->adapter); if (ret < 0) - goto rpm_disable; + goto clk_notifier_unregister; pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); @@ -1162,6 +1179,8 @@ static int i2c_imx_probe(struct platform_device *pdev) return 0; /* Return OK */ +clk_notifier_unregister: + clk_notifier_unregister(i2c_imx->clk, &i2c_imx_clk_notifier); rpm_disable: pm_runtime_put_noidle(&pdev->dev); pm_runtime_disable(&pdev->dev); @@ -1195,6 +1214,7 @@ static int i2c_imx_remove(struct platform_device *pdev) imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR); imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR); + clk_notifier_unregister(i2c_imx->clk, &i2c_imx_clk_notifier); clk_disable_unprepare(i2c_imx->clk); pm_runtime_put_noidle(&pdev->dev);