Staging/iio/adc/touchscreen/MXS: add proper clock handling

The delay units inside the LRADC depend on the presence of a 2 kHz clock.
This change enables the clock to be able to use the delay unit for the
touchscreen part of the driver.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
Tested-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/arch/arm/boot/dts/imx23.dtsi b/arch/arm/boot/dts/imx23.dtsi
index 28b5ce2..07caf76 100644 (file)
--- a/arch/arm/boot/dts/imx23.dtsi
+++ b/arch/arm/boot/dts/imx23.dtsi
@@ -430,6 +430,7 @@
                                reg = <0x80050000 0x2000>;
                                interrupts = <36 37 38 39 40 41 42 43 44>;
                                status = "disabled";
+                               clocks = <&clks 26>;
                        };
 
                        spdif@80054000 {

diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dtsi
index 7363fde..175deef 100644 (file)
--- a/arch/arm/boot/dts/imx28.dtsi
+++ b/arch/arm/boot/dts/imx28.dtsi
@@ -902,6 +902,7 @@
                                interrupts = <10 14 15 16 17 18 19
                                                20 21 22 23 24 25>;
                                status = "disabled";
+                               clocks = <&clks 41>;
                        };
 
                        spdif: spdif@80054000 {

diff --git a/drivers/staging/iio/adc/mxs-lradc.c b/drivers/staging/iio/adc/mxs-lradc.c
index 9da64bf..93b25ca 100644 (file)
--- a/drivers/staging/iio/adc/mxs-lradc.c
+++ b/drivers/staging/iio/adc/mxs-lradc.c
@@ -35,6 +35,7 @@
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/input.h>
+#include <linux/clk.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
@@ -134,6 +135,8 @@ struct mxs_lradc {
        void __iomem            *base;
        int                     irq[13];
 
+       struct clk              *clk;
+
        uint32_t                *buffer;
        struct iio_trigger      *trig;
 
@@ -922,6 +925,17 @@ static int mxs_lradc_probe(struct platform_device *pdev)
        if (IS_ERR(lradc->base))
                return PTR_ERR(lradc->base);
 
+       lradc->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(lradc->clk)) {
+               dev_err(dev, "Failed to get the delay unit clock\n");
+               return PTR_ERR(lradc->clk);
+       }
+       ret = clk_prepare_enable(lradc->clk);
+       if (ret != 0) {
+               dev_err(dev, "Failed to enable the delay unit clock\n");
+               return ret;
+       }
+
        INIT_WORK(&lradc->ts_work, mxs_lradc_ts_work);
 
        /* Check if touchscreen is enabled in DT. */
@@ -1014,6 +1028,7 @@ static int mxs_lradc_remove(struct platform_device *pdev)
        mxs_lradc_trigger_remove(iio);
        iio_triggered_buffer_cleanup(iio);
 
+       clk_disable_unprepare(lradc->clk);
        return 0;
 }