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Subject[RFC PATCH] spi: zynqmp: Add pm runtime support
Date
This patch adds runtime pm functions.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Naga Sureshkumar Relli <nagasure@xilinx.com>
---
drivers/spi/spi-zynqmp-gqspi.c | 86 ++++++++++++++++++++++++++++++++++--------
1 file changed, 70 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 18aeace..26d1ac3 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -20,6 +20,7 @@
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
@@ -135,6 +136,7 @@
#define GQSPI_DMA_UNALIGN 0x3
#define GQSPI_DEFAULT_NUM_CS 1 /* Default number of chip selects */

+#define SPI_AUTOSUSPEND_TIMEOUT 3000
enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};

/**
@@ -356,21 +358,9 @@ static void zynqmp_qspi_copy_read_data(struct zynqmp_qspi *xqspi,
static int zynqmp_prepare_transfer_hardware(struct spi_master *master)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
- int ret;
-
- ret = clk_enable(xqspi->refclk);
- if (ret)
- return ret;
-
- ret = clk_enable(xqspi->pclk);
- if (ret)
- goto clk_err;

zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
return 0;
-clk_err:
- clk_disable(xqspi->refclk);
- return ret;
}

/**
@@ -387,8 +377,6 @@ static int zynqmp_unprepare_transfer_hardware(struct spi_master *master)
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);

zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
- clk_disable(xqspi->refclk);
- clk_disable(xqspi->pclk);
return 0;
}

@@ -959,11 +947,67 @@ static int __maybe_unused zynqmp_qspi_resume(struct device *dev)

spi_master_resume(master);

+ clk_disable(xqspi->refclk);
+ clk_disable(xqspi->pclk);
return 0;
}

-static SIMPLE_DEV_PM_OPS(zynqmp_qspi_dev_pm_ops, zynqmp_qspi_suspend,
- zynqmp_qspi_resume);
+/**
+ * zynqmp_runtime_suspend - Runtime suspend method for the SPI driver
+ * @dev: Address of the platform_device structure
+ *
+ * This function disables the clocks
+ *
+ * Return: Always 0
+ */
+static int __maybe_unused zynqmp_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
+
+ clk_disable(xqspi->refclk);
+ clk_disable(xqspi->pclk);
+
+ return 0;
+}
+
+/**
+ * zynqmp_runtime_resume - Runtime resume method for the SPI driver
+ * @dev: Address of the platform_device structure
+ *
+ * This function enables the clocks
+ *
+ * Return: 0 on success and error value on error
+ */
+static int __maybe_unused zynqmp_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
+ int ret;
+
+ 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;
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops zynqmp_qspi_dev_pm_ops = {
+ SET_RUNTIME_PM_OPS(zynqmp_runtime_suspend,
+ zynqmp_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(zynqmp_qspi_suspend, zynqmp_qspi_resume)
+};

/**
* zynqmp_qspi_probe: Probe method for the QSPI driver
@@ -1023,9 +1067,15 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
goto clk_dis_pclk;
}

+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
/* QSPI controller initializations */
zynqmp_qspi_init_hw(xqspi);

+ pm_runtime_mark_last_busy(&pdev->dev);
+ pm_runtime_put_autosuspend(&pdev->dev);
xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq <= 0) {
ret = -ENXIO;
@@ -1063,6 +1113,8 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
return 0;

clk_dis_all:
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(xqspi->refclk);
clk_dis_pclk:
clk_disable_unprepare(xqspi->pclk);
@@ -1090,6 +1142,8 @@ static int zynqmp_qspi_remove(struct platform_device *pdev)
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
clk_disable_unprepare(xqspi->refclk);
clk_disable_unprepare(xqspi->pclk);
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);

spi_unregister_master(master);

--
2.7.4
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