[PATCH v1 06/12] dmaengine: dw: move clock operations to platform.c

From: Andy Shevchenko
Date: Tue Aug 19 2014 - 13:29:33 EST


On BayTrail platform DMA is not functional in the PCI mode, whereby it always
failed and exit at the point when it tries to get a clock. It causes the PCI
mode probe to exit with the error message:
dw_dmac_pci: probe of 0000:00:1e.0 failed with error -2

This patch moves clock operations to where it belongs to. Thus, the clock is
provided only in ACPI / non-PCI cases.

Reported-by: Chew, Chiau Ee <chiau.ee.chew@xxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/dma/dw/core.c | 16 ----------------
drivers/dma/dw/internal.h | 2 ++
drivers/dma/dw/platform.c | 25 ++++++++++++++++++++++---
drivers/dma/dw/regs.h | 1 -
4 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 10e43ea..9546b1f 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -11,7 +11,6 @@
*/

#include <linux/bitops.h>
-#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -1488,13 +1487,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
dw->regs = chip->regs;
chip->dw = dw;

- dw->clk = devm_clk_get(chip->dev, "hclk");
- if (IS_ERR(dw->clk))
- return PTR_ERR(dw->clk);
- err = clk_prepare_enable(dw->clk);
- if (err)
- return err;
-
dw_params = dma_read_byaddr(chip->regs, DW_PARAMS);
autocfg = dw_params >> DW_PARAMS_EN & 0x1;

@@ -1665,7 +1657,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
err_dma_register:
free_irq(chip->irq, dw);
err_pdata:
- clk_disable_unprepare(dw->clk);
return err;
}
EXPORT_SYMBOL_GPL(dw_dma_probe);
@@ -1687,8 +1678,6 @@ int dw_dma_remove(struct dw_dma_chip *chip)
channel_clear_bit(dw, CH_EN, dwc->mask);
}

- clk_disable_unprepare(dw->clk);
-
return 0;
}
EXPORT_SYMBOL_GPL(dw_dma_remove);
@@ -1698,7 +1687,6 @@ void dw_dma_shutdown(struct dw_dma_chip *chip)
struct dw_dma *dw = chip->dw;

dw_dma_off(dw);
- clk_disable_unprepare(dw->clk);
}
EXPORT_SYMBOL_GPL(dw_dma_shutdown);

@@ -1709,8 +1697,6 @@ int dw_dma_suspend(struct dw_dma_chip *chip)
struct dw_dma *dw = chip->dw;

dw_dma_off(dw);
- clk_disable_unprepare(dw->clk);
-
return 0;
}
EXPORT_SYMBOL_GPL(dw_dma_suspend);
@@ -1719,9 +1705,7 @@ int dw_dma_resume(struct dw_dma_chip *chip)
{
struct dw_dma *dw = chip->dw;

- clk_prepare_enable(dw->clk);
dma_writel(dw, CFG, DW_CFG_DMA_EN);
-
return 0;
}
EXPORT_SYMBOL_GPL(dw_dma_resume);
diff --git a/drivers/dma/dw/internal.h b/drivers/dma/dw/internal.h
index 2c8d02f..82258a1 100644
--- a/drivers/dma/dw/internal.h
+++ b/drivers/dma/dw/internal.h
@@ -21,12 +21,14 @@
* @dev: struct device of the DMA controller
* @irq: irq line
* @regs: memory mapped I/O space
+ * @clk: hclk clock
* @dw: struct dw_dma that is filed by dw_dma_probe()
*/
struct dw_dma_chip {
struct device *dev;
int irq;
void __iomem *regs;
+ struct clk *clk;
struct dw_dma *dw;
};

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 860c9ac..d50077e 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -178,10 +178,17 @@ static int dw_probe(struct platform_device *pdev)

chip->dev = dev;

- err = dw_dma_probe(chip, pdata);
+ chip->clk = devm_clk_get(chip->dev, "hclk");
+ if (IS_ERR(chip->clk))
+ return PTR_ERR(chip->clk);
+ err = clk_prepare_enable(chip->clk);
if (err)
return err;

+ err = dw_dma_probe(chip, pdata);
+ if (err)
+ goto err_dw_dma_probe;
+
platform_set_drvdata(pdev, chip);

if (pdev->dev.of_node) {
@@ -196,6 +203,10 @@ static int dw_probe(struct platform_device *pdev)
dw_dma_acpi_controller_register(chip->dw);

return 0;
+
+err_dw_dma_probe:
+ clk_disable_unprepare(chip->clk);
+ return err;
}

static int dw_remove(struct platform_device *pdev)
@@ -205,7 +216,10 @@ static int dw_remove(struct platform_device *pdev)
if (pdev->dev.of_node)
of_dma_controller_free(pdev->dev.of_node);

- return dw_dma_remove(chip);
+ dw_dma_remove(chip);
+ clk_disable_unprepare(chip->clk);
+
+ return 0;
}

static void dw_shutdown(struct platform_device *pdev)
@@ -213,6 +227,7 @@ static void dw_shutdown(struct platform_device *pdev)
struct dw_dma_chip *chip = platform_get_drvdata(pdev);

dw_dma_shutdown(chip);
+ clk_disable_unprepare(chip->clk);
}

#ifdef CONFIG_OF
@@ -238,7 +253,10 @@ static int dw_suspend_late(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct dw_dma_chip *chip = platform_get_drvdata(pdev);

- return dw_dma_suspend(chip);
+ dw_dma_suspend(chip);
+ clk_disable_unprepare(chip->clk);
+
+ return 0;
}

static int dw_resume_early(struct device *dev)
@@ -246,6 +264,7 @@ static int dw_resume_early(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct dw_dma_chip *chip = platform_get_drvdata(pdev);

+ clk_prepare_enable(chip->clk);
return dw_dma_resume(chip);
}

diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 0e82d99..00d27a9 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -251,7 +251,6 @@ struct dw_dma {
void __iomem *regs;
struct dma_pool *desc_pool;
struct tasklet_struct tasklet;
- struct clk *clk;

/* channels */
struct dw_dma_chan *chan;
--
2.1.0

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