[PATCH v3 2/2] i2c: New bus driver for the Qualcomm QUP I2C controller
Emilio López
emilio at elopez.com.ar
Thu Feb 20 21:53:56 EST 2014
Hi Bjorn,
El 20/02/14 21:38, Bjorn Andersson escribió:
> This bus driver supports the QUP i2c hardware controller in the Qualcomm SOCs.
> The Qualcomm Universal Peripheral Engine (QUP) is a general purpose data path
> engine with input/output FIFOs and an embedded i2c mini-core. The driver
> supports FIFO mode (for low bandwidth applications) and block mode (interrupt
> generated for each block-size data transfer).
>
> Cc: Andy Gross <agross at codeaurora.org>
> Cc: Stephen Boyd <sboyd at codeaurora.org>
> Signed-off-by: Ivan T. Ivanov <iivanov at mm-sol.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson at sonymobile.com>
> ---
I'm not familiar with the subsystem nor the hardware, so I had a look
around for general stuff. I have some minor comments to make on the
probe code.
(snip)
> +static int qup_i2c_probe(struct platform_device *pdev)
> +{
> + static const int blk_sizes[] = {4, 16, 32};
> + struct device_node *node = pdev->dev.of_node;
> + struct qup_i2c_dev *qup;
> + unsigned long one_bit_t;
> + struct resource *res;
> + u32 val, io_mode, hw_ver, size;
> + int ret, fs_div, hs_div;
> + int src_clk_freq;
> + int clk_freq;
> +
> + qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
> + if (!qup)
> + return -ENOMEM;
> +
> + qup->dev = &pdev->dev;
> + init_completion(&qup->xfer);
> + platform_set_drvdata(pdev, qup);
> +
> + clk_freq = 100000;
> + if (!of_property_read_u32(node, "clock-frequency", &val))
> + clk_freq = val;
val will be modified only if no error occurs, so you may rewrite this
bit as
+ u32 clk_freq = 100000;
...
+ of_property_read_u32(node, "clock-frequency", &clk_freq)
> +
> + /* We support frequencies up to FAST Mode (400KHz) */
> + if (clk_freq <= 0 || clk_freq > 400000) {
And you can drop the < check when it's unsigned.
> + dev_err(qup->dev, "clock frequency not supported %d\n",
> + clk_freq);
> + return -EIO;
EIO?
Cheers,
Emilio
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