From: Han Xu <han...@nxp.com>

        Enable the runtime power management for lpspi module.

Signed-off-by: Han Xu <han...@nxp.com>
Reviewed-by: Frank Li <frank...@nxp.com>
---
 drivers/spi/spi-fsl-lpspi.c | 117 ++++++++++++++++++++++++++++--------
 1 file changed, 92 insertions(+), 25 deletions(-)

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 5802f188051b..3e935db5ff02 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -16,7 +16,9 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
@@ -24,6 +26,8 @@
 
 #define DRIVER_NAME "fsl_lpspi"
 
+#define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */
+
 /* i.MX7ULP LPSPI registers */
 #define IMX7ULP_VERID  0x0
 #define IMX7ULP_PARAM  0x4
@@ -150,13 +154,9 @@ static int lpspi_prepare_xfer_hardware(struct 
spi_controller *controller)
                                spi_controller_get_devdata(controller);
        int ret;
 
-       ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
-       if (ret)
-               return ret;
-
-       ret = clk_prepare_enable(fsl_lpspi->clk_per);
-       if (ret) {
-               clk_disable_unprepare(fsl_lpspi->clk_ipg);
+       ret = pm_runtime_get_sync(fsl_lpspi->dev);
+       if (ret < 0) {
+               dev_err(fsl_lpspi->dev, "failed to enable clock\n");
                return ret;
        }
 
@@ -168,8 +168,8 @@ static int lpspi_unprepare_xfer_hardware(struct 
spi_controller *controller)
        struct fsl_lpspi_data *fsl_lpspi =
                                spi_controller_get_devdata(controller);
 
-       clk_disable_unprepare(fsl_lpspi->clk_ipg);
-       clk_disable_unprepare(fsl_lpspi->clk_per);
+       pm_runtime_mark_last_busy(fsl_lpspi->dev);
+       pm_runtime_put_autosuspend(fsl_lpspi->dev);
 
        return 0;
 }
@@ -476,6 +476,45 @@ static irqreturn_t fsl_lpspi_isr(int irq, void *dev_id)
        return IRQ_NONE;
 }
 
+int fsl_lpspi_runtime_resume(struct device *dev)
+{
+       struct fsl_lpspi_data *fsl_lpspi = dev_get_drvdata(dev);
+       int ret;
+
+       ret = clk_prepare_enable(fsl_lpspi->clk_per);
+       if (ret)
+               return ret;
+
+       ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
+       if (ret) {
+               clk_disable_unprepare(fsl_lpspi->clk_per);
+               return ret;
+       }
+
+       return 0;
+}
+
+int fsl_lpspi_runtime_suspend(struct device *dev)
+{
+       struct fsl_lpspi_data *fsl_lpspi = dev_get_drvdata(dev);
+
+       clk_disable_unprepare(fsl_lpspi->clk_per);
+       clk_disable_unprepare(fsl_lpspi->clk_ipg);
+
+       return 0;
+}
+
+static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi)
+{
+       struct device *dev = fsl_lpspi->dev;
+
+       pm_runtime_enable(dev);
+       pm_runtime_set_autosuspend_delay(dev, FSL_LPSPI_RPM_TIMEOUT);
+       pm_runtime_use_autosuspend(dev);
+
+       return 0;
+}
+
 static int fsl_lpspi_probe(struct platform_device *pdev)
 {
        struct fsl_lpspi_data *fsl_lpspi;
@@ -501,6 +540,7 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 
        fsl_lpspi = spi_controller_get_devdata(controller);
        fsl_lpspi->dev = &pdev->dev;
+       dev_set_drvdata(&pdev->dev, fsl_lpspi);
        fsl_lpspi->is_slave = of_property_read_bool((&pdev->dev)->of_node,
                                                    "spi-slave");
 
@@ -547,28 +587,21 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
                goto out_controller_put;
        }
 
-       ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
-       if (ret) {
-               dev_err(&pdev->dev,
-                       "can't enable lpspi ipg clock, ret=%d\n", ret);
+       /* enable the clock */
+       ret = fsl_lpspi_init_rpm(fsl_lpspi);
+       if (ret)
                goto out_controller_put;
-       }
 
-       ret = clk_prepare_enable(fsl_lpspi->clk_per);
-       if (ret) {
-               dev_err(&pdev->dev,
-                       "can't enable lpspi per clock, ret=%d\n", ret);
-               clk_disable_unprepare(fsl_lpspi->clk_ipg);
-               goto out_controller_put;
+       ret = pm_runtime_get_sync(fsl_lpspi->dev);
+       if (ret < 0) {
+               dev_err(fsl_lpspi->dev, "failed to enable clock\n");
+               return ret;
        }
 
        temp = readl(fsl_lpspi->base + IMX7ULP_PARAM);
        fsl_lpspi->txfifosize = 1 << (temp & 0x0f);
        fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f);
 
-       clk_disable_unprepare(fsl_lpspi->clk_per);
-       clk_disable_unprepare(fsl_lpspi->clk_ipg);
-
        ret = devm_spi_register_controller(&pdev->dev, controller);
        if (ret < 0) {
                dev_err(&pdev->dev, "spi_register_controller error.\n");
@@ -589,16 +622,50 @@ static int fsl_lpspi_remove(struct platform_device *pdev)
        struct fsl_lpspi_data *fsl_lpspi =
                                spi_controller_get_devdata(controller);
 
-       clk_disable_unprepare(fsl_lpspi->clk_per);
-       clk_disable_unprepare(fsl_lpspi->clk_ipg);
+       pm_runtime_disable(fsl_lpspi->dev);
+
+       spi_master_put(controller);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int fsl_lpspi_suspend(struct device *dev)
+{
+       int ret;
+
+       pinctrl_pm_select_sleep_state(dev);
+       ret = pm_runtime_force_suspend(dev);
+       return ret;
+}
+
+static int fsl_lpspi_resume(struct device *dev)
+{
+       int ret;
+
+       ret = pm_runtime_force_resume(dev);
+       if (ret) {
+               dev_err(dev, "Error in resume: %d\n", ret);
+               return ret;
+       }
+
+       pinctrl_pm_select_default_state(dev);
 
        return 0;
 }
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops fsl_lpspi_pm_ops = {
+       SET_RUNTIME_PM_OPS(fsl_lpspi_runtime_suspend,
+                               fsl_lpspi_runtime_resume, NULL)
+       SET_SYSTEM_SLEEP_PM_OPS(fsl_lpspi_suspend, fsl_lpspi_resume)
+};
 
 static struct platform_driver fsl_lpspi_driver = {
        .driver = {
                .name = DRIVER_NAME,
                .of_match_table = fsl_lpspi_dt_ids,
+               .pm = &fsl_lpspi_pm_ops,
        },
        .probe = fsl_lpspi_probe,
        .remove = fsl_lpspi_remove,
-- 
2.17.1

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