On Fri, Jan 20, 2017 at 04:43:47PM +0800, Baoyou Xie wrote:
> +static int zx2967_i2c_probe(struct platform_device *pdev)
> +{
> + struct resource *res;
> + struct zx2967_i2c_info *zx_i2c = NULL;
> + struct clk *clk;
> + void __iomem *reg_base;
> + int ret = 0;
> +
> + zx_i2c = devm_kzalloc(&pdev->dev, sizeof(*zx_i2c), GFP_KERNEL);
> + if (!zx_i2c)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "missing io resource\n");
> + return -EINVAL;
> + }
> +
> + reg_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(reg_base))
> + return PTR_ERR(reg_base);
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "missing controller clock");
> + return PTR_ERR(clk);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to enable i2c_clk\n");
> + return ret;
> + }
> +
> + of_property_read_u32(pdev->dev.of_node,
> + "clock-frequency", &zx_i2c->clk_freq);
> + zx_i2c->reg_base = reg_base;
> + zx_i2c->clk = clk;
> + zx_i2c->irq = platform_get_irq(pdev, 0);
> + zx_i2c->id = pdev->id;
> + zx_i2c->dev = &pdev->dev;
> +
> + zx_i2c->pin_scl = devm_pinctrl_get_select(&pdev->dev, "scl");
> + if (IS_ERR(zx_i2c->pin_scl))
> + dev_info(&pdev->dev, "scl pin is not specified in dts\n");
> +
> + zx_i2c->pin_sda = devm_pinctrl_get_select(&pdev->dev, "sda");
> + if (IS_ERR(zx_i2c->pin_sda))
> + dev_info(&pdev->dev, "sda pin is not specified in dts\n");
I don't understand why this is necessary. For most cases, we only need
to specify needed pins in property 'pinctrl-0' and 'default' in
'pinctrl-names', and pinctrl/driver core will just set up the pins for
the device.
Shawn
