[PATCH v4 3/3] dmaengine: vdma: Add clock support

Kedareswara rao Appana
2016-04-22T06:13:50Z

Added basic clock support for axi dma's.
The clocks are requested at probe and released at remove.

Reviewed-by: Shubhrajyoti Datta <shubhraj-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Kedareswara rao Appana <appanad-gjFFaj9aHVfQT0dZR+AlfA@public.gmane.org>
---
Changes for v4:
---> Documented struct members as suggested by Soren.
---> Fixed required clock according to binding but a failure is ignored
in the cdma case as suggested by Soren.
---> Removed unnecessary IS_ERR checks during disabling the clocks.
Changes for v3:
---> Added clock support for all the AXI DMA's.
---> Fixed clk_unprepare leak during probe fail as suggested by Moritz.
---> Fixed comment driver specifically asks for the clocks it needs and return
an error if a mandatory clock is missing as suggested by soren.
Changes for v2:
---> None.

drivers/dma/xilinx/xilinx_vdma.c | 226 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 224 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 255cdca..51c633f 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -44,6 +44,7 @@
#include <linux/of_platform.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
+#include <linux/clk.h>

#include "../dmaengine.h"

@@ -344,6 +345,9 @@ struct xilinx_dma_chan {

struct dma_config {
enum xdma_ip_type dmatype;
+ int (*clk_init)(struct platform_device *pdev, struct clk **axi_clk,
+ struct clk **tx_clk, struct clk **txs_clk,
+ struct clk **rx_clk, struct clk **rxs_clk);
};

/**
@@ -355,7 +359,13 @@ struct dma_config {
* @has_sg: Specifies whether Scatter-Gather is present or not
* @flush_on_fsync: Flush on frame sync
* @ext_addr: Indicates 64 bit addressing is supported by dma device
+ * @pdev: Platform device structure pointer
* @dma_config: DMA config structure
+ * @axi_clk: DMA Axi4-lite interace clock
+ * @tx_clk: DMA mm2s clock
+ * @txs_clk: DMA mm2s stream clock
+ * @rx_clk: DMA s2mm clock
+ * @rxs_clk: DMA s2mm stream clock
*/
struct xilinx_dma_device {
void __iomem *regs;
@@ -365,7 +375,13 @@ struct xilinx_dma_device {
bool has_sg;
u32 flush_on_fsync;
bool ext_addr;
+ struct platform_device *pdev;
const struct dma_config *dma_config;
+ struct clk *axi_clk;
+ struct clk *tx_clk;
+ struct clk *txs_clk;
+ struct clk *rx_clk;
+ struct clk *rxs_clk;
};

/* Macros */
@@ -1757,6 +1773,195 @@ static void xilinx_dma_chan_remove(struct xilinx_dma_chan *chan)
list_del(&chan->common.device_node);
}

+static int axidma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
+ struct clk **tx_clk, struct clk **rx_clk,
+ struct clk **sg_clk, struct clk **tmp_clk)
+{
+ int err;
+
+ *tmp_clk = NULL;
+
+ *axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
+ if (IS_ERR(*axi_clk)) {
+ err = PTR_ERR(*axi_clk);
+ dev_err(&pdev->dev, "failed to get axi_aclk (%u)\n", err);
+ return err;
+ }
+
+ *tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
+ if (IS_ERR(*tx_clk))
+ *tx_clk = NULL;
+
+ *rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
+ if (IS_ERR(*rx_clk))
+ *rx_clk = NULL;
+
+ *sg_clk = devm_clk_get(&pdev->dev, "m_axi_sg_aclk");
+ if (IS_ERR(*sg_clk))
+ *sg_clk = NULL;
+
+ err = clk_prepare_enable(*axi_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable axi_clk (%u)\n", err);
+ return err;
+ }
+
+ err = clk_prepare_enable(*tx_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable tx_clk (%u)\n", err);
+ goto err_disable_axiclk;
+ }
+
+ err = clk_prepare_enable(*rx_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable rx_clk (%u)\n", err);
+ goto err_disable_txclk;
+ }
+
+ err = clk_prepare_enable(*sg_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable sg_clk (%u)\n", err);
+ goto err_disable_rxclk;
+ }
+
+ return 0;
+
+err_disable_rxclk:
+ clk_disable_unprepare(*rx_clk);
+err_disable_txclk:
+ clk_disable_unprepare(*tx_clk);
+err_disable_axiclk:
+ clk_disable_unprepare(*axi_clk);
+
+ return err;
+}
+
+static int axicdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
+ struct clk **dev_clk, struct clk **tmp_clk,
+ struct clk **tmp1_clk, struct clk **tmp2_clk)
+{
+ int err;
+
+ *tmp_clk = NULL;
+ *tmp1_clk = NULL;
+ *tmp2_clk = NULL;
+
+ *axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
+ if (IS_ERR(*axi_clk)) {
+ err = PTR_ERR(*axi_clk);
+ dev_err(&pdev->dev, "failed to get axi_clk (%u)\n", err);
+ return err;
+ }
+
+ *dev_clk = devm_clk_get(&pdev->dev, "m_axi_aclk");
+ if (IS_ERR(*dev_clk)) {
+ err = PTR_ERR(*dev_clk);
+ dev_err(&pdev->dev, "failed to get dev_clk (%u)\n", err);
+ return err;
+ }
+
+ err = clk_prepare_enable(*axi_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable axi_clk (%u)\n", err);
+ return err;
+ }
+
+ err = clk_prepare_enable(*dev_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable dev_clk (%u)\n", err);
+ goto err_disable_axiclk;
+ }
+
+ return 0;
+
+err_disable_axiclk:
+ clk_disable_unprepare(*axi_clk);
+
+ return err;
+}
+
+static int axivdma_clk_init(struct platform_device *pdev, struct clk **axi_clk,
+ struct clk **tx_clk, struct clk **txs_clk,
+ struct clk **rx_clk, struct clk **rxs_clk)
+{
+ int err;
+
+ *axi_clk = devm_clk_get(&pdev->dev, "s_axi_lite_aclk");
+ if (IS_ERR(*axi_clk)) {
+ err = PTR_ERR(*axi_clk);
+ dev_err(&pdev->dev, "failed to get axi_aclk (%u)\n", err);
+ return err;
+ }
+
+ *tx_clk = devm_clk_get(&pdev->dev, "m_axi_mm2s_aclk");
+ if (IS_ERR(*tx_clk))
+ *tx_clk = NULL;
+
+ *txs_clk = devm_clk_get(&pdev->dev, "m_axis_mm2s_aclk");
+ if (IS_ERR(*txs_clk))
+ *txs_clk = NULL;
+
+ *rx_clk = devm_clk_get(&pdev->dev, "m_axi_s2mm_aclk");
+ if (IS_ERR(*rx_clk))
+ *rx_clk = NULL;
+
+ *rxs_clk = devm_clk_get(&pdev->dev, "s_axis_s2mm_aclk");
+ if (IS_ERR(*rxs_clk))
+ *rxs_clk = NULL;
+
+ err = clk_prepare_enable(*axi_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable axi_clk (%u)\n", err);
+ return err;
+ }
+
+ err = clk_prepare_enable(*tx_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable tx_clk (%u)\n", err);
+ goto err_disable_axiclk;
+ }
+
+ err = clk_prepare_enable(*txs_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable txs_clk (%u)\n", err);
+ goto err_disable_txclk;
+ }
+
+ err = clk_prepare_enable(*rx_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable rx_clk (%u)\n", err);
+ goto err_disable_txsclk;
+ }
+
+ err = clk_prepare_enable(*rxs_clk);
+ if (err) {
+ dev_err(&pdev->dev, "failed to enable rxs_clk (%u)\n", err);
+ goto err_disable_rxclk;
+ }
+
+ return 0;
+
+err_disable_rxclk:
+ clk_disable_unprepare(*rx_clk);
+err_disable_txsclk:
+ clk_disable_unprepare(*txs_clk);
+err_disable_txclk:
+ clk_disable_unprepare(*tx_clk);
+err_disable_axiclk:
+ clk_disable_unprepare(*axi_clk);
+
+ return err;
+}
+
+static void xdma_disable_allclks(struct xilinx_dma_device *xdev)
+{
+ clk_disable_unprepare(xdev->rxs_clk);
+ clk_disable_unprepare(xdev->rx_clk);
+ clk_disable_unprepare(xdev->txs_clk);
+ clk_disable_unprepare(xdev->tx_clk);
+ clk_disable_unprepare(xdev->axi_clk);
+}
+
/**
* xilinx_dma_chan_probe - Per Channel Probing
* It get channel features from the device tree entry and
@@ -1900,14 +2105,17 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec,

static const struct dma_config axidma_config = {
.dmatype = XDMA_TYPE_AXIDMA,
+ .clk_init = axidma_clk_init,
};

static const struct dma_config axicdma_config = {
.dmatype = XDMA_TYPE_CDMA,
+ .clk_init = axicdma_clk_init,
};

static const struct dma_config axivdma_config = {
.dmatype = XDMA_TYPE_VDMA,
+ .clk_init = axivdma_clk_init,
};

static const struct of_device_id xilinx_dma_of_ids[] = {
@@ -1926,6 +2134,9 @@ MODULE_DEVICE_TABLE(of, xilinx_dma_of_ids);
*/
static int xilinx_dma_probe(struct platform_device *pdev)
{
+ int (*clk_init)(struct platform_device *, struct clk **, struct clk **,
+ struct clk **, struct clk **, struct clk **)
+ = axivdma_clk_init;
struct device_node *node = pdev->dev.of_node;
struct xilinx_dma_device *xdev;
struct device_node *child, *np = pdev->dev.of_node;
@@ -1943,10 +2154,17 @@ static int xilinx_dma_probe(struct platform_device *pdev)
const struct of_device_id *match;

match = of_match_node(xilinx_dma_of_ids, np);
- if (match && match->data)
+ if (match && match->data) {
xdev->dma_config = match->data;
+ clk_init = xdev->dma_config->clk_init;
+ }
}

+ err = clk_init(pdev, &xdev->axi_clk, &xdev->tx_clk, &xdev->txs_clk,
+ &xdev->rx_clk, &xdev->rxs_clk);
+ if (err)
+ return err;
+
/* Request and map I/O memory */
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
xdev->regs = devm_ioremap_resource(&pdev->dev, io);
@@ -2019,7 +2237,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
for_each_child_of_node(node, child) {
err = xilinx_dma_chan_probe(xdev, child);
if (err < 0)
- goto error;
+ goto disable_clks;
}

if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) {
@@ -2043,6 +2261,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)

return 0;

+disable_clks:
+ xdma_disable_allclks(xdev);
error:
for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++)
if (xdev->chan[i])
@@ -2070,6 +2290,8 @@ static int xilinx_dma_remove(struct platform_device *pdev)
if (xdev->chan[i])
xilinx_dma_chan_remove(xdev->chan[i]);

+ xdma_disable_allclks(xdev);
+
return 0;
}

--
2.1.2

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