target/linux/layerscape/patches-5.4/808-i2c-0016-LF-162-i2c-imx-Defer-probing-if-EDMA-not-available.patch

   1 From 9de3b340d84b75f93081f871b640a065cba4ded0 Mon Sep 17 00:00:00 2001
   2 From: Peng Ma <peng.ma@nxp.com>
   3 Date: Tue, 26 Nov 2019 16:02:00 +0800
   4 Subject: [PATCH] LF-162: i2c: imx: Defer probing if EDMA not available
   5
   6 EDMA may be not available or defered due to dependencies on
   7 other modules, If these scenarios is encountered, we should
   8 defer probing.
   9
  10 Signed-off-by: Peng Ma <peng.ma@nxp.com>
  11 ---
  12  drivers/i2c/busses/i2c-imx.c | 16 +++++++++++-----
  13  1 file changed, 11 insertions(+), 5 deletions(-)
  14
  15 --- a/drivers/i2c/busses/i2c-imx.c
  16 +++ b/drivers/i2c/busses/i2c-imx.c
  17 @@ -369,8 +369,8 @@ static void i2c_imx_reset_regs(struct im
  18  }
  19
  20  /* Functions for DMA support */
  21 -static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
  22 -                                               dma_addr_t phy_addr)
  23 +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
  24 +                              dma_addr_t phy_addr)
  25  {
  26         struct imx_i2c_dma *dma;
  27         struct dma_slave_config dma_sconfig;
  28 @@ -379,7 +379,7 @@ static void i2c_imx_dma_request(struct i
  29
  30         dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
  31         if (!dma)
  32 -               return;
  33 +               return -ENOMEM;
  34
  35         dma->chan_tx = dma_request_chan(dev, "tx");
  36         if (IS_ERR(dma->chan_tx)) {
  37 @@ -424,7 +424,7 @@ static void i2c_imx_dma_request(struct i
  38         dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
  39                 dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
  40
  41 -       return;
  42 +       return 0;
  43
  44  fail_rx:
  45         dma_release_channel(dma->chan_rx);
  46 @@ -432,6 +432,8 @@ fail_tx:
  47         dma_release_channel(dma->chan_tx);
  48  fail_al:
  49         devm_kfree(dev, dma);
  50 +
  51 +       return ret;
  52  }
  53
  54  static void i2c_imx_dma_callback(void *arg)
  55 @@ -1633,10 +1635,14 @@ static int i2c_imx_probe(struct platform
  56         dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
  57
  58         /* Init DMA config if supported */
  59 -       i2c_imx_dma_request(i2c_imx, phy_addr);
  60 +       ret = i2c_imx_dma_request(i2c_imx, phy_addr);
  61 +       if (ret == -EPROBE_DEFER)
  62 +               goto i2c_adapter_remove;
  63
  64         return 0;   /* Return OK */
  65
  66 +i2c_adapter_remove:
  67 +       i2c_del_adapter(&i2c_imx->adapter);
  68  clk_notifier_unregister:
  69         clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
  70         free_irq(irq, i2c_imx);