spi: spi-zynqmp-gqspi: fix clk_enable/disable imbalance issue

The clks "pclk" and "ref_clk" are enabled twice during the probe. The
first time is in the function zynqmp_qspi_probe and the second time is
in zynqmp_qspi_setup_op which is called by devm_spi_register_controller.
Then calling zynqmp_qspi_remove (rmmod this module) to disable these clks
will trigger a warning as below:

[  309.124604] Unpreparing enabled qspi_ref
[  309.128641] WARNING: CPU: 1 PID: 537 at drivers/clk/clk.c:824 clk_core_unprepare+0x108/0x110

Since pm_runtime works now, clks can be enabled/disabled by calling
zynqmp_runtime_suspend/resume. So we don't need to enable these clks
explicitly in zynqmp_qspi_setup_op. Remove them to fix this issue.

And remove clk enabling/disabling in zynqmp_qspi_resume because there is
no spi transfer operation so enabling ref_clk is redundant meanwhile pclk
is not disabled for it is shared with other peripherals.

Furthermore replace clk_enable/disable with clk_prepare_enable and
clk_disable_unprepare in runtime_suspend/resume functions.

Fixes: 1c26372e5aa9 ("spi: spi-zynqmp-gqspi: Update driver to use spi-mem framework")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Link: https://lore.kernel.org/r/20210416004652.2975446-2-quanyang.wang@windriver.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 32e53f379e9b159162d8b06c1cf9523b6432573f..f9056f0a480cef18ce17855d27f70c820194aee8 100644 (file)
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -487,24 +487,10 @@ static int zynqmp_qspi_setup_op(struct spi_device *qspi)
 {
        struct spi_controller *ctlr = qspi->master;
        struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);
-       struct device *dev = &ctlr->dev;
-       int ret;
 
        if (ctlr->busy)
                return -EBUSY;
 
-       ret = clk_enable(xqspi->refclk);
-       if (ret) {
-               dev_err(dev, "Cannot enable device clock.\n");
-               return ret;
-       }
-
-       ret = clk_enable(xqspi->pclk);
-       if (ret) {
-               dev_err(dev, "Cannot enable APB clock.\n");
-               clk_disable(xqspi->refclk);
-               return ret;
-       }
        zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
 
        return 0;
@@ -863,26 +849,9 @@ static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
 static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
 {
        struct spi_controller *ctlr = dev_get_drvdata(dev);
-       struct zynqmp_qspi *xqspi = spi_controller_get_devdata(ctlr);
-       int ret = 0;
-
-       ret = clk_enable(xqspi->pclk);
-       if (ret) {
-               dev_err(dev, "Cannot enable APB clock.\n");
-               return ret;
-       }
-
-       ret = clk_enable(xqspi->refclk);
-       if (ret) {
-               dev_err(dev, "Cannot enable device clock.\n");
-               clk_disable(xqspi->pclk);
-               return ret;
-       }
 
        spi_controller_resume(ctlr);
 
-       clk_disable(xqspi->refclk);
-       clk_disable(xqspi->pclk);
        return 0;
 }
 
@@ -898,8 +867,8 @@ static int __maybe_unused zynqmp_runtime_suspend(struct device *dev)
 {
        struct zynqmp_qspi *xqspi = (struct zynqmp_qspi *)dev_get_drvdata(dev);
 
-       clk_disable(xqspi->refclk);
-       clk_disable(xqspi->pclk);
+       clk_disable_unprepare(xqspi->refclk);
+       clk_disable_unprepare(xqspi->pclk);
 
        return 0;
 }
@@ -917,16 +886,16 @@ static int __maybe_unused zynqmp_runtime_resume(struct device *dev)
        struct zynqmp_qspi *xqspi = (struct zynqmp_qspi *)dev_get_drvdata(dev);
        int ret;
 
-       ret = clk_enable(xqspi->pclk);
+       ret = clk_prepare_enable(xqspi->pclk);
        if (ret) {
                dev_err(dev, "Cannot enable APB clock.\n");
                return ret;
        }
 
-       ret = clk_enable(xqspi->refclk);
+       ret = clk_prepare_enable(xqspi->refclk);
        if (ret) {
                dev_err(dev, "Cannot enable device clock.\n");
-               clk_disable(xqspi->pclk);
+               clk_disable_unprepare(xqspi->pclk);
                return ret;
        }
 
@@ -1136,13 +1105,11 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
                goto remove_master;
        }
 
-       init_completion(&xqspi->data_completion);
-
        xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
        if (IS_ERR(xqspi->refclk)) {
                dev_err(dev, "ref_clk clock not found.\n");
                ret = PTR_ERR(xqspi->refclk);
-               goto clk_dis_pclk;
+               goto remove_master;
        }
 
        ret = clk_prepare_enable(xqspi->pclk);
@@ -1157,6 +1124,8 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
                goto clk_dis_pclk;
        }
 
+       init_completion(&xqspi->data_completion);
+
        mutex_init(&xqspi->op_lock);
 
        pm_runtime_use_autosuspend(&pdev->dev);