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

Reviewed-by: Shubhrajyoti Datta <shubh...@xilinx.com>
Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
---
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 | 225 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 223 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 5bfaa32..41bb5b3 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);
 };
 
 /**
@@ -365,7 +369,13 @@ 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 +1767,200 @@ 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 txs_clk (%u)\n", err);
+               goto err_disable_txclk;
+       }
+
+       err = clk_prepare_enable(*sg_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_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_aclk (%u)\n", err);
+               return err;
+       }
+
+       *dev_clk = devm_clk_get(&pdev->dev, "m_axi_aclk");
+       if (IS_ERR(*dev_clk))
+               *dev_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(*dev_clk);
+       if (err) {
+               dev_err(&pdev->dev, "failed to enable tx_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)
+{
+       if (!IS_ERR(xdev->rxs_clk))
+               clk_disable_unprepare(xdev->rxs_clk);
+       if (!IS_ERR(xdev->rx_clk))
+               clk_disable_unprepare(xdev->rx_clk);
+       if (!IS_ERR(xdev->txs_clk))
+               clk_disable_unprepare(xdev->txs_clk);
+       if (!IS_ERR(xdev->tx_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 +2104,17 @@ 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[] = {
@@ -1926,9 +2133,13 @@ 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;
+       struct clk *axi_clk, *tx_clk, *txs_clk, *rx_clk, *rxs_clk;
        struct resource *io;
        u32 num_frames, addr_width;
        int i, err;
@@ -1943,10 +2154,16 @@ 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, &axi_clk, &tx_clk, &txs_clk, &rx_clk, &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 +2236,7 @@ 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 +2260,8 @@ 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 +2289,8 @@ 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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