[PATCH] i2c: imx: Defer probing if EDMA not available

Peng Ma
2019-11-27T07:12:18Z

EDMA may be not available or defered due to dependencies on
other modules, If these scenarios is encountered, we should
defer probing.

Signed-off-by: Peng Ma <peng.ma@nxp.com>
---
drivers/i2c/busses/i2c-imx.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 40111a3..c2b0693 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -369,8 +369,8 @@ static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx)
}

/* Functions for DMA support */
-static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
- dma_addr_t phy_addr)
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
{
struct imx_i2c_dma *dma;
struct dma_slave_config dma_sconfig;
@@ -379,7 +379,7 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,

dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
if (!dma)
- return;
+ return -ENOMEM;

dma->chan_tx = dma_request_chan(dev, "tx");
if (IS_ERR(dma->chan_tx)) {
@@ -424,7 +424,7 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));

- return;
+ return 0;

fail_rx:
dma_release_channel(dma->chan_rx);
@@ -432,6 +432,8 @@ static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma_release_channel(dma->chan_tx);
fail_al:
devm_kfree(dev, dma);
+
+ return ret;
}

static void i2c_imx_dma_callback(void *arg)
@@ -1605,10 +1607,14 @@ static int i2c_imx_probe(struct platform_device *pdev)
dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");

/* Init DMA config if supported */
- i2c_imx_dma_request(i2c_imx, phy_addr);
+ ret = i2c_imx_dma_request(i2c_imx, phy_addr);
+ if (ret == -EPROBE_DEFER)
+ goto i2c_adapter_remove;

return 0; /* Return OK */

+i2c_adapter_remove:
+ i2c_del_adapter(&i2c_imx->adapter);
clk_notifier_unregister:
clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb);
rpm_disable:
--
2.9.5