MLK-16785: spi: lpspi: enable runtime pm for lpspi

enable the runtime pm for lpspi module

 BuildInfo:
  - SCFW 66189d08, IMX-MKIMAGE ea027c4b, ATF
  - U-Boot 2017.03-imx_4.9.51_8qm_beta1_8qxp_alpha+g325ac1e

Signed-off-by: Han Xu <han.xu@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
(cherry picked from commit cc7e95b14a5c34dbe2375acbe3d512dc0c2962fd)

1 files changed, 66 insertions, 26 deletions

diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 11e300f939eb..0872607280bf 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -35,9 +35,12 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
+#include <linux/pm_runtime.h>
 
 #define DRIVER_NAME "fsl_lpspi"
 
+#define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */
+
 /* i.MX7ULP LPSPI registers */
 #define IMX7ULP_VERID	0x0
 #define IMX7ULP_PARAM	0x4
@@ -393,6 +396,31 @@ fsl_lpspi_prepare_message(struct spi_master *master, struct spi_message *msg)
 	struct fsl_lpspi_data *fsl_lpspi = spi_master_get_devdata(master);
 	int ret;
 
+	ret = pm_runtime_get_sync(fsl_lpspi->dev);
+	if (ret < 0) {
+		dev_err(fsl_lpspi->dev, "failed to enable clock\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int
+fsl_lpspi_unprepare_message(struct spi_master *master, struct spi_message *msg)
+{
+	struct fsl_lpspi_data *fsl_lpspi = spi_master_get_devdata(master);
+
+	pm_runtime_mark_last_busy(fsl_lpspi->dev);
+	pm_runtime_put_autosuspend(fsl_lpspi->dev);
+
+	return 0;
+}
+
+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;
@@ -406,10 +434,9 @@ fsl_lpspi_prepare_message(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 
-static int
-fsl_lpspi_unprepare_message(struct spi_master *master, struct spi_message *msg)
+int fsl_lpspi_runtime_suspend(struct device *dev)
 {
-	struct fsl_lpspi_data *fsl_lpspi = spi_master_get_devdata(master);
+	struct fsl_lpspi_data *fsl_lpspi = dev_get_drvdata(dev);
 
 	clk_disable_unprepare(fsl_lpspi->clk_per);
 	clk_disable_unprepare(fsl_lpspi->clk_ipg);
@@ -417,6 +444,17 @@ fsl_lpspi_unprepare_message(struct spi_master *master, struct spi_message *msg)
 	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 device_node *np = pdev->dev.of_node;
@@ -439,6 +477,7 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	fsl_lpspi = spi_master_get_devdata(master);
 	fsl_lpspi->bitbang.master = master;
 	fsl_lpspi->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, fsl_lpspi);
 
 	for (i = 0; i < master->num_chipselect; i++) {
 		int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
@@ -496,38 +535,28 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	}
 
 	/* enable the clock */
-	ret = clk_prepare_enable(fsl_lpspi->clk_per);
+	ret = fsl_lpspi_init_rpm(fsl_lpspi);
 	if (ret)
-		goto out_clk_per;
-
-	ret = clk_prepare_enable(fsl_lpspi->clk_ipg);
-	if (ret)
-		goto out_clk_ipg;
+		goto out_master_put;
 
 	ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0,
 			       dev_name(&pdev->dev), fsl_lpspi);
 	if (ret) {
 		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
-		goto out_clk_ipg;
+		goto out_master_put;
 	}
 
 	master->dev.of_node = pdev->dev.of_node;
 	ret = spi_bitbang_start(&fsl_lpspi->bitbang);
 	if (ret) {
 		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
-		goto out_clk_ipg;
+		goto out_master_put;
 	}
 
 	dev_info(fsl_lpspi->dev, "lpspi probed\n");
 
-	clk_disable_unprepare(fsl_lpspi->clk_ipg);
-	clk_disable_unprepare(fsl_lpspi->clk_per);
 	return ret;
 
-out_clk_ipg:
-	clk_disable_unprepare(fsl_lpspi->clk_ipg);
-out_clk_per:
-	clk_disable_unprepare(fsl_lpspi->clk_per);
 out_master_put:
 	spi_master_put(master);
 
@@ -540,9 +569,8 @@ static int fsl_lpspi_remove(struct platform_device *pdev)
 	struct fsl_lpspi_data *fsl_lpspi = spi_master_get_devdata(master);
 
 	spi_bitbang_stop(&fsl_lpspi->bitbang);
+	pm_runtime_disable(fsl_lpspi->dev);
 
-	clk_unprepare(fsl_lpspi->clk_per);
-	clk_unprepare(fsl_lpspi->clk_ipg);
 	spi_master_put(master);
 
 	return 0;
@@ -551,27 +579,39 @@ static int fsl_lpspi_remove(struct platform_device *pdev)
 #ifdef CONFIG_PM_SLEEP
 static int fsl_lpspi_suspend(struct device *dev)
 {
+	int ret;
+
 	pinctrl_pm_select_sleep_state(dev);
-	return 0;
+	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 SIMPLE_DEV_PM_OPS(imx_lpspi_pm, fsl_lpspi_suspend, fsl_lpspi_resume);
-#define IMX_LPSPI_PM	(&imx_lpspi_pm)
-#else
-#define IMX_LPSPI_PM	NULL
-#endif
+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 = IMX_LPSPI_PM,
+			.pm = &fsl_lpspi_pm_ops,
 		},
 	.probe = fsl_lpspi_probe,
 	.remove = fsl_lpspi_remove,