Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751217AbdILB6q (ORCPT ); Mon, 11 Sep 2017 21:58:46 -0400 Received: from mail-io0-f172.google.com ([209.85.223.172]:34222 "EHLO mail-io0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751045AbdILB6n (ORCPT ); Mon, 11 Sep 2017 21:58:43 -0400 X-Google-Smtp-Source: AOwi7QDu0/XdPl5rPoTpFQdlEY3M754OlXD2gY+HyjNaYgiz0y8L27MVOyB6XISIlk/l7rouzLC60PvdcdgJTm7XZP0= MIME-Version: 1.0 In-Reply-To: <20170911201145.31257-2-fcooper@ti.com> References: <20170911201145.31257-1-fcooper@ti.com> <20170911201145.31257-2-fcooper@ti.com> From: Baolin Wang Date: Tue, 12 Sep 2017 09:58:42 +0800 Message-ID: Subject: Re: [PATCH v4 1/2] i2c: davinci: Add PM Runtime Support To: Franklin S Cooper Jr Cc: Wolfram Sang , Rob Herring , linux@armlinux.org.uk, nsekhar@ti.com, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, LKML , linux-arm-kernel@lists.infradead.org, grygorii.strashko@ti.com, vigneshr@ti.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6667 Lines: 207 Hi, On 12 September 2017 at 04:11, Franklin S Cooper Jr wrote: > 66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain > unlike other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime > is required to insure the power domain used by the specific I2C instance is > properly turned on along with its functional clock. > > Signed-off-by: Franklin S Cooper Jr > --- > Version 4 changes: > Fix wording on error message > Fix additional error path > > Version 3 changes: > Remove several statements that set clk to NULL > Fix error path > > drivers/i2c/busses/i2c-davinci.c | 67 +++++++++++++++++++++++++++++++++------- > 1 file changed, 55 insertions(+), 12 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c > index b8c4353..a2d9f7c 100644 > --- a/drivers/i2c/busses/i2c-davinci.c > +++ b/drivers/i2c/busses/i2c-davinci.c > @@ -36,6 +36,7 @@ > #include > #include > #include > +#include > > /* ----- global defines ----------------------------------------------- */ > > @@ -122,6 +123,9 @@ > /* set the SDA GPIO low */ > #define DAVINCI_I2C_DCLR_PDCLR1 BIT(1) > > +/* timeout for pm runtime autosuspend */ > +#define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */ > + > struct davinci_i2c_dev { > struct device *dev; > void __iomem *base; > @@ -541,10 +545,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > > dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); > > + ret = pm_runtime_get_sync(dev->dev); > + if (ret < 0) { > + dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret); > + pm_runtime_put_noidle(dev->dev); > + return ret; > + } > + > ret = i2c_davinci_wait_bus_not_busy(dev); > if (ret < 0) { > dev_warn(dev->dev, "timeout waiting for bus ready\n"); > - return ret; > + goto out; > } > > for (i = 0; i < num; i++) { > @@ -552,14 +563,19 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num, > ret); > if (ret < 0) > - return ret; > + goto out; > } > > + ret = num; > #ifdef CONFIG_CPU_FREQ > complete(&dev->xfr_complete); > #endif > > - return num; > +out: > + pm_runtime_mark_last_busy(dev->dev); > + pm_runtime_put_autosuspend(dev->dev); > + > + return ret; > } > > static u32 i2c_davinci_func(struct i2c_adapter *adap) > @@ -599,6 +615,9 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) > int count = 0; > u16 w; > > + if (pm_runtime_suspended(dev->dev)) > + return IRQ_NONE; > + > while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) { > dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); > if (count++ == 100) { > @@ -802,13 +821,24 @@ static int davinci_i2c_probe(struct platform_device *pdev) > dev->clk = devm_clk_get(&pdev->dev, NULL); > if (IS_ERR(dev->clk)) > return PTR_ERR(dev->clk); > - clk_prepare_enable(dev->clk); You removed clk enable here, I think it can not work if we did not open CONFIG_PM macro. I think you should keep clk enable here, and set rpm active by pm_runtime_set_active() before issuing pm_runtime_enable(). > > mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > dev->base = devm_ioremap_resource(&pdev->dev, mem); > if (IS_ERR(dev->base)) { > - r = PTR_ERR(dev->base); > - goto err_unuse_clocks; > + return PTR_ERR(dev->base); > + } > + > + pm_runtime_set_autosuspend_delay(dev->dev, > + DAVINCI_I2C_PM_TIMEOUT); > + pm_runtime_use_autosuspend(dev->dev); > + > + pm_runtime_enable(dev->dev); > + > + r = pm_runtime_get_sync(dev->dev); > + if (r < 0) { > + dev_err(dev->dev, "failed to runtime_get device: %d\n", r); > + pm_runtime_put_noidle(dev->dev); > + return r; > } > > i2c_davinci_init(dev); > @@ -849,27 +879,40 @@ static int davinci_i2c_probe(struct platform_device *pdev) > if (r) > goto err_unuse_clocks; > > + pm_runtime_mark_last_busy(dev->dev); > + pm_runtime_put_autosuspend(dev->dev); > + > return 0; > > err_unuse_clocks: > - clk_disable_unprepare(dev->clk); > - dev->clk = NULL; > + pm_runtime_dont_use_autosuspend(dev->dev); > + pm_runtime_put_sync(dev->dev); > + pm_runtime_disable(dev->dev); > + > return r; > } > > static int davinci_i2c_remove(struct platform_device *pdev) > { > struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); > + int ret; > > i2c_davinci_cpufreq_deregister(dev); > > i2c_del_adapter(&dev->adapter); > > - clk_disable_unprepare(dev->clk); > - dev->clk = NULL; > + ret = pm_runtime_get_sync(&pdev->dev); > + if (ret < 0) { > + pm_runtime_put_noidle(&pdev->dev); > + return ret; > + } > > davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); > > + pm_runtime_dont_use_autosuspend(dev->dev); > + pm_runtime_put_sync(dev->dev); > + pm_runtime_disable(dev->dev); > + > return 0; > } > > @@ -880,7 +923,6 @@ static int davinci_i2c_suspend(struct device *dev) > > /* put I2C into reset */ > davinci_i2c_reset_ctrl(i2c_dev, 0); > - clk_disable_unprepare(i2c_dev->clk); > > return 0; > } > @@ -889,7 +931,6 @@ static int davinci_i2c_resume(struct device *dev) > { > struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); > > - clk_prepare_enable(i2c_dev->clk); > /* take I2C out of reset */ > davinci_i2c_reset_ctrl(i2c_dev, 1); > > @@ -899,6 +940,8 @@ static int davinci_i2c_resume(struct device *dev) > static const struct dev_pm_ops davinci_i2c_pm = { > .suspend = davinci_i2c_suspend, > .resume = davinci_i2c_resume, > + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, > + pm_runtime_force_resume) > }; > > #define davinci_i2c_pm_ops (&davinci_i2c_pm) > -- > 2.9.4.dirty > -- Baolin.wang Best Regards