mmc: moxart: fix probe logic

Jonas Jensen wanted to submit a patch for these, but apparently
forgot about it. I stumbled over this symptom first:

drivers/built-in.o: In function `moxart_probe':
:(.text+0x2af128): undefined reference to `of_dma_request_slave_channel'

This is because of_dma_request_slave_channel is an internal helper
and not exported to loadable module. I'm changing the driver to
use dma_request_slave_channel_reason() instead.

Further problems from inspection:

* The remove function must not call kfree on the host pointer,
  because it is allocated together with the mmc_host.

* The clock is never released

* The dma_cap_mask_t is completely unused and can be removed

* deferred probing does not work if the dma driver is loaded
  after the mmc driver.

This patch should fix all of the above.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 9 insertions, 11 deletions

diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
index d2a1ef61ec97..006f1862444b 100644
--- a/drivers/mmc/host/moxart-mmc.c
+++ b/drivers/mmc/host/moxart-mmc.c
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/delay.h>
+#include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/blkdev.h>
 #include <linux/dma-mapping.h>
@@ -562,7 +563,6 @@ static int moxart_probe(struct platform_device *pdev)
         struct dma_slave_config cfg;
         struct clk *clk;
         void __iomem *reg_mmc;
-        dma_cap_mask_t mask;
         int irq, ret;
         u32 i;
 
@@ -586,9 +586,8 @@ static int moxart_probe(struct platform_device *pdev)
                 goto out;
         }
 
-        clk = of_clk_get(node, 0);
+        clk = devm_clk_get(dev, NULL);
         if (IS_ERR(clk)) {
-                dev_err(dev, "of_clk_get failed\n");
                 ret = PTR_ERR(clk);
                 goto out;
         }
@@ -603,9 +602,6 @@ static int moxart_probe(struct platform_device *pdev)
         if (ret)
                 goto out;
 
-        dma_cap_zero(mask);
-        dma_cap_set(DMA_SLAVE, mask);
-
         host = mmc_priv(mmc);
         host->mmc = mmc;
         host->base = reg_mmc;
@@ -613,8 +609,8 @@ static int moxart_probe(struct platform_device *pdev)
         host->timeout = msecs_to_jiffies(1000);
         host->sysclk = clk_get_rate(clk);
         host->fifo_width = readl(host->base + REG_FEATURE) << 2;
-        host->dma_chan_tx = of_dma_request_slave_channel(node, "tx");
-        host->dma_chan_rx = of_dma_request_slave_channel(node, "rx");
+        host->dma_chan_tx = dma_request_slave_channel_reason(dev, "tx");
+        host->dma_chan_rx = dma_request_slave_channel_reason(dev, "rx");
 
         spin_lock_init(&host->lock);
 
@@ -624,6 +620,11 @@ static int moxart_probe(struct platform_device *pdev)
         mmc->ocr_avail = 0xffff00;      /* Support 2.0v - 3.6v power. */
 
         if (IS_ERR(host->dma_chan_tx) || IS_ERR(host->dma_chan_rx)) {
+                if (PTR_ERR(host->dma_chan_tx) == -EPROBE_DEFER ||
+                    PTR_ERR(host->dma_chan_rx) == -EPROBE_DEFER) {
+                        ret = -EPROBE_DEFER;
+                        goto out;
+                }
                 dev_dbg(dev, "PIO mode transfer enabled\n");
                 host->have_dma = false;
         } else {
@@ -702,9 +703,6 @@ static int moxart_remove(struct platform_device *pdev)
                 writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
                        host->base + REG_CLOCK_CONTROL);
         }
-
-        kfree(host);
-
         return 0;
 }