Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752194AbaJPJ0W (ORCPT ); Thu, 16 Oct 2014 05:26:22 -0400 Received: from eusmtp01.atmel.com ([212.144.249.242]:15600 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbaJPJ0U (ORCPT ); Thu, 16 Oct 2014 05:26:20 -0400 From: Wenyou Yang To: CC: , , , , Subject: [PATCH v2] spi/atmel: add support for runtime PM Date: Thu, 16 Oct 2014 17:23:10 +0800 Message-ID: <1413451390-22859-1-git-send-email-wenyou.yang@atmel.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Drivers should put the device into low power states proactively whenever the device is not in use. Thus implement support for runtime PM and use the autosuspend feature to make sure that we can still perform well in case we see lots of SPI traffic within short period of time. Signed-off-by: Wenyou Yang --- Change log v2: add check the return value of clk_prepare_enable(). drivers/spi/spi-atmel.c | 68 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 61 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 649dcb5..bc9d969 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -26,6 +26,7 @@ #include #include #include +#include /* SPI register offsets */ #define SPI_CR 0x0000 @@ -191,6 +192,8 @@ #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000)) +#define AUTOSUSPEND_TIMEOUT 2000 + struct atmel_spi_dma { struct dma_chan *chan_rx; struct dma_chan *chan_tx; @@ -1313,6 +1316,7 @@ static int atmel_spi_probe(struct platform_device *pdev) master->setup = atmel_spi_setup; master->transfer_one_message = atmel_spi_transfer_one_message; master->cleanup = atmel_spi_cleanup; + master->auto_runtime_pm = true; platform_set_drvdata(pdev, master); as = spi_master_get_devdata(master); @@ -1385,6 +1389,11 @@ static int atmel_spi_probe(struct platform_device *pdev) dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n", (unsigned long)regs->start, irq); + pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + ret = devm_spi_register_master(&pdev->dev, master); if (ret) goto out_free_dma; @@ -1392,6 +1401,9 @@ static int atmel_spi_probe(struct platform_device *pdev) return 0; out_free_dma: + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + if (as->use_dma) atmel_spi_release_dma(as); @@ -1413,6 +1425,8 @@ static int atmel_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct atmel_spi *as = spi_master_get_devdata(master); + pm_runtime_get_sync(&pdev->dev); + /* reset the hardware and block queue progress */ spin_lock_irq(&as->lock); if (as->use_dma) { @@ -1430,9 +1444,13 @@ static int atmel_spi_remove(struct platform_device *pdev) clk_disable_unprepare(as->clk); + pm_runtime_put_noidle(&pdev->dev); + pm_runtime_disable(&pdev->dev); + return 0; } +#ifdef CONFIG_PM #ifdef CONFIG_PM_SLEEP static int atmel_spi_suspend(struct device *dev) { @@ -1447,9 +1465,10 @@ static int atmel_spi_suspend(struct device *dev) return ret; } - clk_disable_unprepare(as->clk); - - pinctrl_pm_select_sleep_state(dev); + if (!pm_runtime_suspended(dev)) { + clk_disable_unprepare(as->clk); + pinctrl_pm_select_sleep_state(dev); + } return 0; } @@ -1460,9 +1479,12 @@ static int atmel_spi_resume(struct device *dev) struct atmel_spi *as = spi_master_get_devdata(master); int ret; - pinctrl_pm_select_default_state(dev); - - clk_prepare_enable(as->clk); + if (!pm_runtime_suspended(dev)) { + pinctrl_pm_select_default_state(dev); + ret = clk_prepare_enable(as->clk); + if (ret) + return ret; + } /* Start the queue running */ ret = spi_master_resume(master); @@ -1471,9 +1493,41 @@ static int atmel_spi_resume(struct device *dev) return ret; } +#endif -static SIMPLE_DEV_PM_OPS(atmel_spi_pm_ops, atmel_spi_suspend, atmel_spi_resume); +#ifdef CONFIG_PM_RUNTIME +static int atmel_spi_runtime_suspend(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct atmel_spi *as = spi_master_get_devdata(master); + clk_disable_unprepare(as->clk); + pinctrl_pm_select_sleep_state(dev); + + return 0; +} + +static int atmel_spi_runtime_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct atmel_spi *as = spi_master_get_devdata(master); + int ret; + + pinctrl_pm_select_default_state(dev); + + ret = clk_prepare_enable(as->clk); + if (ret) + return ret; + + return 0; +} +#endif + +static const struct dev_pm_ops atmel_spi_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume) + SET_RUNTIME_PM_OPS(atmel_spi_runtime_suspend, + atmel_spi_runtime_resume, NULL) +}; #define ATMEL_SPI_PM_OPS (&atmel_spi_pm_ops) #else #define ATMEL_SPI_PM_OPS NULL -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/