Re: [PATCH v1 03/11] clk: starfive: Add StarFive JH7110 System-Top-Group clock driver

From: Stephen Boyd
Date: Wed Jan 25 2023 - 21:34:03 EST


Quoting Xingyu Wu (2023-01-19 18:44:37)
> diff --git a/drivers/clk/starfive/clk-starfive-jh7110-stg.c b/drivers/clk/starfive/clk-starfive-jh7110-stg.c
> new file mode 100644
> index 000000000000..c2740f44e796
> --- /dev/null
> +++ b/drivers/clk/starfive/clk-starfive-jh7110-stg.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * StarFive JH7110 System-Top-Group Clock Driver
> + *
> + * Copyright (C) 2022 StarFive Technology Co., Ltd.
> + */
> +
> +#include <linux/clk.h>

Is this include used? If not, please remove.

> +#include <linux/clk-provider.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +#include <dt-bindings/clock/starfive,jh7110-crg.h>
> +
> +#include "clk-starfive-jh71x0.h"
> +
[...]
> +static int jh7110_stgcrg_probe(struct platform_device *pdev)
> +{
> + struct jh71x0_clk_priv *priv;
> + unsigned int idx;
> + int ret;
> +
> + priv = devm_kzalloc(&pdev->dev,
> + struct_size(priv, reg, JH7110_STGCLK_END),
> + GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + spin_lock_init(&priv->rmw_lock);
> + priv->dev = &pdev->dev;
> + priv->base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(priv->base))
> + return PTR_ERR(priv->base);
> +
> + dev_set_drvdata(priv->dev, priv->base);
> +
> + for (idx = 0; idx < JH7110_STGCLK_END; idx++) {
> + u32 max = jh7110_stgclk_data[idx].max;
> + struct clk_parent_data parents[4] = {};
> + struct clk_init_data init = {
> + .name = jh7110_stgclk_data[idx].name,
> + .ops = starfive_jh71x0_clk_ops(max),
> + .parent_data = parents,
> + .num_parents =
> + ((max & JH71X0_CLK_MUX_MASK) >> JH71X0_CLK_MUX_SHIFT) + 1,
> + .flags = jh7110_stgclk_data[idx].flags,
> + };
> + struct jh71x0_clk *clk = &priv->reg[idx];
> + unsigned int i;
> +
> + for (i = 0; i < init.num_parents; i++) {
> + unsigned int pidx = jh7110_stgclk_data[idx].parents[i];
> +
> + if (pidx < JH7110_STGCLK_END)
> + parents[i].hw = &priv->reg[pidx].hw;
> + else if (pidx == JH7110_STGCLK_OSC)
> + parents[i].fw_name = "osc";
> + else if (pidx == JH7110_STGCLK_HIFI4_CORE)
> + parents[i].fw_name = "hifi4_core";
> + else if (pidx == JH7110_STGCLK_STG_AXIAHB)
> + parents[i].fw_name = "stg_axiahb";
> + else if (pidx == JH7110_STGCLK_USB_125M)
> + parents[i].fw_name = "usb_125m";
> + else if (pidx == JH7110_STGCLK_CPU_BUS)
> + parents[i].fw_name = "cpu_bus";
> + else if (pidx == JH7110_STGCLK_HIFI4_AXI)
> + parents[i].fw_name = "hifi4_axi";
> + else if (pidx == JH7110_STGCLK_NOCSTG_BUS)
> + parents[i].fw_name = "nocstg_bus";
> + else if (pidx == JH7110_STGCLK_APB_BUS)
> + parents[i].fw_name = "apb_bus";

Can this be an array lookup instead of a pile of conditions?

if (pidx < JH7110_STGCLK_END)
...
else
parents[i].fw_name = fw_table[pidx - JH7110_STGCLK_END];

Or even better, don't use strings at all and just make the 'pidx' number
(possibly minus the end constant) be the 'clocks' property index that
you want.

> + }
> +
> + clk->hw.init = &init;
> + clk->idx = idx;
> + clk->max_div = max & JH71X0_CLK_DIV_MASK;
> +
> + ret = devm_clk_hw_register(&pdev->dev, &clk->hw);
> + if (ret)
> + return ret;
> + }
> +
> + ret = devm_of_clk_add_hw_provider(&pdev->dev, jh7110_stgclk_get, priv);
> + if (ret)
> + return ret;
> +
> + return jh7110_reset_controller_register(priv, "reset-stg", 2);

Is this also devm-ified?