On 08/28, Martin Blumenstingl wrote:

+static int meson8b_init_clk(struct meson8b_dwmac *dwmac)
+{
+	struct clk_init_data init;
+	int i, ret;
+	struct device *dev = &dwmac->pdev->dev;
+	char clk_name[32];
+	const char *clk_div_parents[1];
+	const char *mux_parent_names[MUX_CLK_NUM_PARENTS];
+	static struct clk_div_table clk_25m_div_table[] = {
+		{ .val = 0, .div = 5 },
+		{ .val = 1, .div = 10 },
+		{ /* sentinel */ },
+	};
+
+	/* get the mux parents from DT */
+	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+		char name[16];
+
+		snprintf(name, sizeof(name), "clkin%d", i);
+		dwmac->m250_mux_parent[i] = devm_clk_get(dev, name);
+		if (IS_ERR(dwmac->m250_mux_parent[i])) {
+			ret = PTR_ERR(dwmac->m250_mux_parent[i]);
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev, "Missing clock %s\n", name);
+			return ret;
+		}
+
+		mux_parent_names[i] =
+			__clk_get_name(dwmac->m250_mux_parent[i]);
+	}
+
+	/* create the m250_mux */
+	snprintf(clk_name, sizeof(clk_name), "%s#m250_sel", dev_name(dev));
+	init.name = clk_name;
+	init.ops = &clk_mux_ops;
+	init.flags = CLK_IS_BASIC;

Please don't use this flag unless you need it.

+	init.parent_names = mux_parent_names;
+	init.num_parents = MUX_CLK_NUM_PARENTS;
+
+	dwmac->m250_mux.reg = dwmac->regs + PRG_ETH0;
+	dwmac->m250_mux.shift = PRG_ETH0_CLK_M250_SEL_SHIFT;
+	dwmac->m250_mux.mask = PRG_ETH0_CLK_M250_SEL_MASK;
+	dwmac->m250_mux.flags = 0;
+	dwmac->m250_mux.table = NULL;
+	dwmac->m250_mux.hw.init = &init;
+
+	dwmac->m250_mux_clk = devm_clk_register(dev, &dwmac->m250_mux.hw);
+	if (WARN_ON(PTR_ERR_OR_ZERO(dwmac->m250_mux_clk)))

Why not if(WARN_ON(IS_ERR())? The OR_ZERO part seems confusing.

+		return PTR_ERR(dwmac->m250_mux_clk);
+
+	/* create the m250_div */
+	snprintf(clk_name, sizeof(clk_name), "%s#m250_div", dev_name(dev));
+	init.name = devm_kstrdup(dev, clk_name, GFP_KERNEL);
+	init.ops = &clk_divider_ops;
+	init.flags = CLK_IS_BASIC | CLK_SET_RATE_PARENT;
+	clk_div_parents[0] = __clk_get_name(dwmac->m250_mux_clk);
+	init.parent_names = clk_div_parents;
+	init.num_parents = ARRAY_SIZE(clk_div_parents);
+
+	dwmac->m250_div.reg = dwmac->regs + PRG_ETH0;
+	dwmac->m250_div.shift = PRG_ETH0_CLK_M250_DIV_SHIFT;
+	dwmac->m250_div.width = PRG_ETH0_CLK_M250_DIV_WIDTH;
+	dwmac->m250_div.hw.init = &init;
+	dwmac->m250_div.flags = CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO;
+
+	dwmac->m250_div_clk = devm_clk_register(dev, &dwmac->m250_div.hw);

We've been trying to move away from devm_clk_register() to
devm_clk_hw_register() so that clk providers aren't also clk
consumers. Obviously in this case this driver is a provider and a
consumer, so this isn't as important. Kevin did something similar
in the mmc driver, so I'll reiterate what I said on that patch.
Perhaps we should make __clk_create_clk() into a real clk
provider API so that we can use devm_clk_hw_register() here and
then generate a clk for this device. That would allow us to have
proper consumer tracking without relying on the clk that is
returned from clk_register() (the intent is to make that clk
instance internal to the framework).

+	if (WARN_ON(PTR_ERR_OR_ZERO(dwmac->m250_div_clk)))
+		return PTR_ERR(dwmac->m250_div_clk);
+
+	/* create the m25_div */
+	snprintf(clk_name, sizeof(clk_name), "%s#m25_div", dev_name(dev));
+	init.name = devm_kstrdup(dev, clk_name, GFP_KERNEL);
+	init.ops = &clk_divider_ops;
+	init.flags = CLK_IS_BASIC | CLK_SET_RATE_PARENT;
+	clk_div_parents[0] = __clk_get_name(dwmac->m250_div_clk);
+	init.parent_names = clk_div_parents;
+	init.num_parents = ARRAY_SIZE(clk_div_parents);
+
+	dwmac->m25_div.reg = dwmac->regs + PRG_ETH0;
+	dwmac->m25_div.shift = PRG_ETH0_CLK_M25_DIV_SHIFT;
+	dwmac->m25_div.width = PRG_ETH0_CLK_M25_DIV_WIDTH;
+	dwmac->m25_div.table = clk_25m_div_table;
+	dwmac->m25_div.hw.init = &init;
+	dwmac->m25_div.flags = CLK_DIVIDER_ALLOW_ZERO;
+
+	dwmac->m25_div_clk = devm_clk_register(dev, &dwmac->m25_div.hw);
+	if (WARN_ON(PTR_ERR_OR_ZERO(dwmac->m25_div_clk)))
+		return PTR_ERR(dwmac->m25_div_clk);
+
+	return 0;

This could be return WARN_ON(PTR_ERR_OR_ZERO(...))

+
+static int meson8b_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct resource *res;
+	struct meson8b_dwmac *dwmac;
+	int ret;
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return PTR_ERR(plat_dat);
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return -ENODEV;
+

You can drop the above two lines and just call
devm_ioremap_resource().

+	dwmac->regs = devm_ioremap_resource(&pdev->dev, res);

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project