Re: [PATCH v2 3/5] clk: aspeed: Add platform driver and register PLLs

From: Stephen Boyd
Date: Mon Oct 02 2017 - 17:27:37 EST


On 09/21, Joel Stanley wrote:
> @@ -160,6 +191,104 @@ static struct clk_hw *aspeed_calc_pll(const char *name, u32 val)
> mult, div);
> }
>
> +static int __init aspeed_clk_probe(struct platform_device *pdev)

Drop __init? Should be a section mismatch with __init here.

> +{
> + const struct aspeed_clk_soc_data *soc_data;
> + const struct clk_div_table *mac_div_table;
> + const struct clk_div_table *div_table;
> + struct device *dev = &pdev->dev;
> + struct regmap *map;
> + struct clk_hw *hw;
> + u32 val, rate;
> +
> + map = syscon_node_to_regmap(dev->of_node);
> + if (IS_ERR(map)) {
> + dev_err(dev, "no syscon regmap\n");
> + return PTR_ERR(map);
> + }
> +
> + /* SoC generations share common layouts but have different divisors */
> + soc_data = of_device_get_match_data(&pdev->dev);

Check for soc_data being NULL.

> + div_table = soc_data->div_table;
> + mac_div_table = soc_data->mac_div_table;
> +
> + /* UART clock div13 setting */
> + regmap_read(map, ASPEED_MISC_CTRL, &val);
> + if (val & BIT(12))

What does BIT(12) mean? #define or comment please.

> + rate = 24000000 / 13;
> + else
> + rate = 24000000;
> + /* TODO: Find the parent data for the uart clock */
> + hw = clk_hw_register_fixed_rate(NULL, "uart", NULL, 0, rate);
> + aspeed_clk_data->hws[ASPEED_CLK_UART] = hw;
> +
> + /*
> + * Memory controller (M-PLL) PLL. This clock is configured by the
> + * bootloader, and is exposed to Linux as a read-only clock rate.
> + */
> + regmap_read(map, ASPEED_MPLL_PARAM, &val);
> + aspeed_clk_data->hws[ASPEED_CLK_MPLL] = aspeed_calc_pll("mpll", val);
> +
> + /* SD/SDIO clock divider (TODO: There's a gate too) */
> + hw = clk_hw_register_divider_table(NULL, "sdio", "hpll", 0,

Please pass your dev pointer here from the platform device.

> + scu_base + ASPEED_CLK_SELECTION, 12, 3, 0,
> + div_table,
> + &aspeed_clk_lock);

And check for errors? Perhaps use devm_clk_hw_regsiter() APIs and
construct the dividers and muxes directly instead of using the
basic type registration APIs.

> + aspeed_clk_data->hws[ASPEED_CLK_SDIO] = hw;
> +
> + /* MAC AHB bus clock divider */
> + hw = clk_hw_register_divider_table(NULL, "mac", "hpll", 0,
> + scu_base + ASPEED_CLK_SELECTION, 16, 3, 0,
> + mac_div_table,
> + &aspeed_clk_lock);
> + aspeed_clk_data->hws[ASPEED_CLK_MAC] = hw;
> +
> + /* LPC Host (LHCLK) clock divider */
> + hw = clk_hw_register_divider_table(NULL, "lhclk", "hpll", 0,
> + scu_base + ASPEED_CLK_SELECTION, 20, 3, 0,
> + div_table,
> + &aspeed_clk_lock);
> + aspeed_clk_data->hws[ASPEED_CLK_LHCLK] = hw;
> +
> + /* Video Engine (ECLK) mux and clock divider */
> + hw = clk_hw_register_mux(NULL, "eclk_mux",
> + eclk_parents, ARRAY_SIZE(eclk_parents), 0,
> + scu_base + ASPEED_CLK_SELECTION, 2, 2,
> + 0, &aspeed_clk_lock);
> + aspeed_clk_data->hws[ASPEED_CLK_ECLK_MUX] = hw;
> + hw = clk_hw_register_divider_table(NULL, "eclk", "eclk_mux", 0,
> + scu_base + ASPEED_CLK_SELECTION, 20, 3, 0,
> + div_table,
> + &aspeed_clk_lock);
> + aspeed_clk_data->hws[ASPEED_CLK_ECLK] = hw;
> +
> + /* P-Bus (BCLK) clock divider */
> + hw = clk_hw_register_divider_table(NULL, "bclk", "hpll", 0,
> + scu_base + ASPEED_CLK_SELECTION, 0, 2, 0,
> + div_table,
> + &aspeed_clk_lock);
> + aspeed_clk_data->hws[ASPEED_CLK_BCLK] = hw;
> +
> + return 0;
> +};
> +
> +static const struct of_device_id aspeed_clk_dt_ids[] = {
> + { .compatible = "aspeed,ast2400-scu", .data = &ast2400_data },
> + { .compatible = "aspeed,ast2500-scu", .data = &ast2500_data },
> + { },

^
Nitpick, drop the comma

> +};
> +
> +static struct platform_driver aspeed_clk_driver = {
> + .probe = aspeed_clk_probe,
> + .driver = {
> + .name = "aspeed-clk",
> + .of_match_table = aspeed_clk_dt_ids,
> + .suppress_bind_attrs = true,
> + },
> +};
> +builtin_platform_driver(aspeed_clk_driver);
> +
> +

Kill a newline, save the internet.

> static void __init aspeed_ast2400_cc(struct regmap *map)
> {
> struct clk_hw *hw;
--
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