From 9e556dcc55774c9a1032f32baa0e5cfafede8b70 Mon Sep 17 00:00:00 2001 From: Huang Shijie Date: Wed, 23 Oct 2013 16:31:50 +0800 Subject: [PATCH] spi: spi-imx: only enable the clocks when we start to transfer a message Current code keeps the clocks enabled all the time, it wastes the power when there is no operaiton on the spi controller. In order to save the power, this patch adds the two hooks: spi_imx_prepare_message: enable the clocks for this message spi_imx_unprepare_message: disable the clocks. This patch also disables the clocks in the end of the probe. Signed-off-by: Huang Shijie Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 15323d8bd9cf..cc9defe7a7f2 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -749,6 +749,35 @@ static void spi_imx_cleanup(struct spi_device *spi) { } +static int +spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + int ret; + + ret = clk_enable(spi_imx->clk_per); + if (ret) + return ret; + + ret = clk_enable(spi_imx->clk_ipg); + if (ret) { + clk_disable(spi_imx->clk_per); + return ret; + } + + return 0; +} + +static int +spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + clk_disable(spi_imx->clk_ipg); + clk_disable(spi_imx->clk_per); + return 0; +} + static int spi_imx_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; @@ -810,6 +839,8 @@ static int spi_imx_probe(struct platform_device *pdev) spi_imx->bitbang.txrx_bufs = spi_imx_transfer; spi_imx->bitbang.master->setup = spi_imx_setup; spi_imx->bitbang.master->cleanup = spi_imx_cleanup; + spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message; + spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message; spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; init_completion(&spi_imx->xfer_done); @@ -872,6 +903,8 @@ static int spi_imx_probe(struct platform_device *pdev) dev_info(&pdev->dev, "probed\n"); + clk_disable(spi_imx->clk_ipg); + clk_disable(spi_imx->clk_per); return ret; out_clk_put: -- 2.20.1