From f8efb2818158a1d1b654e333ab8d39851c4d1a22 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 15323d8bd9cfa..cc9defe7a7f25 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: -- 2.39.5