Subject: Re: [PATCH v2 2/5] clk: meson: add a driver for the Meson8/8b/8m2 DDR clock controller

From: Stephen Boyd <[email-masked]>
Date: Fri, 08 Nov 2019 14:16:51 -0800

Quoting Martin Blumenstingl (2019-10-27 09:23:25)
> diff --git a/drivers/clk/meson/meson8-ddr.c b/drivers/clk/meson/meson8-ddr.c
> new file mode 100644
> index 000000000000..4aefcc5bdaae
> --- /dev/null
> +++ b/drivers/clk/meson/meson8-ddr.c
> @@ -0,0 +1,152 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Amlogic Meson8 DDR clock controller
> + *
> + * Copyright (C) 2019 Martin Blumenstingl <[email-masked]>
> + */
> +
> +#include <dt-bindings/clock/meson8-ddr-clkc.h>
> +
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/slab.h>

Please include clk-provider.h as this is a clk provider driver.

> +
> +#include "clk-regmap.h"
> +#include "clk-pll.h"
> +
> +#define AM_DDR_PLL_CNTL                        0x00
> +#define AM_DDR_PLL_CNTL1               0x04
> +#define AM_DDR_PLL_CNTL2               0x08
> +#define AM_DDR_PLL_CNTL3               0x0c
> +#define AM_DDR_PLL_CNTL4               0x10
> +#define AM_DDR_PLL_STS                 0x14
> +#define DDR_CLK_CNTL                   0x18
> +#define DDR_CLK_STS                    0x1c
> +
> +static struct clk_regmap meson8_ddr_pll_dco = {
> +       .data = &(struct meson_clk_pll_data){
> +               .en = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 30,
> +                       .width   = 1,
> +               },
> +               .m = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 0,
> +                       .width   = 9,
> +               },
> +               .n = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 9,
> +                       .width   = 5,
> +               },
> +               .l = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 31,
> +                       .width   = 1,
> +               },
> +               .rst = {
> +                       .reg_off = AM_DDR_PLL_CNTL,
> +                       .shift   = 29,
> +                       .width   = 1,
> +               },
> +       },
> +       .hw.init = &(struct clk_init_data){
> +               .name = "ddr_pll_dco",
> +               .ops = &meson_clk_pll_ro_ops,
> +               .parent_data = &(const struct clk_parent_data) {
> +                       .fw_name = "xtal",
> +               },
> +               .num_parents = 1,
> +       },
> +};
> +
> +static struct clk_regmap meson8_ddr_pll = {
> +       .data = &(struct clk_regmap_div_data){
> +               .offset = AM_DDR_PLL_CNTL,
> +               .shift = 16,
> +               .width = 2,
> +               .flags = CLK_DIVIDER_POWER_OF_TWO,
> +       },
> +       .hw.init = &(struct clk_init_data){
> +               .name = "ddr_pll",
> +               .ops = &clk_regmap_divider_ro_ops,
> +               .parent_hws = (const struct clk_hw *[]) {
> +                       &meson8_ddr_pll_dco.hw
> +               },
> +               .num_parents = 1,
> +       },
> +};
> +
> +static struct clk_hw_onecell_data meson8_ddr_clk_hw_onecell_data = {
> +       .hws = {
> +               [DDR_CLKID_DDR_PLL_DCO]         = &meson8_ddr_pll_dco.hw,
> +               [DDR_CLKID_DDR_PLL]             = &meson8_ddr_pll.hw,
> +       },
> +       .num = 2,
> +};
> +
> +static struct clk_regmap *const meson8_ddr_clk_regmaps[] = {
> +       &meson8_ddr_pll_dco,
> +       &meson8_ddr_pll,
> +};
> +
> +static const struct regmap_config meson8_ddr_clkc_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +       .max_register = DDR_CLK_STS,
> +};
> +
> +static int meson8_ddr_clkc_probe(struct platform_device *pdev)
> +{
> +       struct regmap *regmap;
> +       struct resource *res;
> +       void __iomem *base;
> +       struct clk_hw *hw;
> +       int ret, i;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       base = devm_ioremap_resource(&pdev->dev, res);

We have a new function to combine the above two lines. Please use it so
the janitors avoid this file.

> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +
> +       regmap = devm_regmap_init_mmio(&pdev->dev, base,
> +                                      &meson8_ddr_clkc_regmap_config);
> +       if (IS_ERR(regmap))
> +               return PTR_ERR(regmap);
> +
> +       /* Populate regmap */
> +       for (i = 0; i < ARRAY_SIZE(meson8_ddr_clk_regmaps); i++)
> +               meson8_ddr_clk_regmaps[i]->map = regmap;
> +
> +       /* Register all clks */
> +       for (i = 0; i < meson8_ddr_clk_hw_onecell_data.num; i++) {
> +               hw = meson8_ddr_clk_hw_onecell_data.hws[i];
> +
> +               ret = devm_clk_hw_register(&pdev->dev, hw);
> +               if (ret) {
> +                       dev_err(&pdev->dev, "Clock registration failed\n");
> +                       return ret;
> +               }
> +       }
> +
> +       return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
> +                                          &meson8_ddr_clk_hw_onecell_data);
> +}
> +
> +static const struct of_device_id meson8_ddr_clkc_match_table[] = {
> +       { .compatible = "amlogic,meson8-ddr-clkc" },
> +       { .compatible = "amlogic,meson8b-ddr-clkc" },
> +       { /* sentinel */ },

Super nitpick, drop the comma above so that nothing can follow this.

> +};
> +
> +static struct platform_driver meson8_ddr_clkc_driver = {
> +       .probe          = meson8_ddr_clkc_probe,
> +       .driver         = {
> +               .name   = "meson8-ddr-clkc",
> +               .of_match_table = meson8_ddr_clkc_match_table,
> +       },
> +};
> +
> +builtin_platform_driver(meson8_ddr_clkc_driver);
> -- 
> 2.23.0
> 

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