Re: [PATCH V4 1/6] clk: exynos-audss: convert to platform device

[Mike Turquette]

Quoting Andrew Bresticker (2013-09-25 14:12:47)
> The Exynos AudioSS clock controller will later be modified to allow
> input clocks to be specified via device-tree in order to support
> multiple Exynos SoCs.  This will introduce a dependency on the core
> SoC clock controller being initialized first so that the AudioSS driver
> can look up its input clocks, but the order in which clock providers
> are probed in of_clk_init() is not guaranteed.  Since deferred probing
> is not supported in of_clk_init() and the AudioSS block is not the core
> controller, we can initialize it later as a platform device.
> 
> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
> Acked-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>

Acked-by: Mike Turquette <mturquette@xxxxxxxxxx>

> ---
> Changes since v3:
>  - __init -> __exit for module exit function
>  - fixed nits from Sylwester
> Changes since v2:
>  - add error handling to probe callback
>  - fixed ordering of of_clk_{add,del}_provider
>  - fixed nits from Tomasz and Sylwester
> Changes since v1:
>  - add clk_unregister() calls to remove callback
>  - fixed minor nits from Tomasz
> ---
>  drivers/clk/samsung/clk-exynos-audss.c | 104 ++++++++++++++++++++++++++++-----
>  1 file changed, 88 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/clk/samsung/clk-exynos-audss.c b/drivers/clk/samsung/clk-exynos-audss.c
> index 39b40aa..742dabc 100644
> --- a/drivers/clk/samsung/clk-exynos-audss.c
> +++ b/drivers/clk/samsung/clk-exynos-audss.c
> @@ -14,6 +14,8 @@
>  #include <linux/clk-provider.h>
>  #include <linux/of_address.h>
>  #include <linux/syscore_ops.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
>  
>  #include <dt-bindings/clk/exynos-audss-clk.h>
>  
> @@ -62,24 +64,26 @@ static struct syscore_ops exynos_audss_clk_syscore_ops = {
>  #endif /* CONFIG_PM_SLEEP */
>  
>  /* register exynos_audss clocks */
> -static void __init exynos_audss_clk_init(struct device_node *np)
> +static int exynos_audss_clk_probe(struct platform_device *pdev)
>  {
> -       reg_base = of_iomap(np, 0);
> -       if (!reg_base) {
> -               pr_err("%s: failed to map audss registers\n", __func__);
> -               return;
> +       int i, ret = 0;
> +       struct resource *res;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       reg_base = devm_ioremap_resource(&pdev->dev, res);
> +       if (IS_ERR(reg_base)) {
> +               dev_err(&pdev->dev, "failed to map audss registers\n");
> +               return PTR_ERR(reg_base);
>         }
>  
> -       clk_table = kzalloc(sizeof(struct clk *) * EXYNOS_AUDSS_MAX_CLKS,
> +       clk_table = devm_kzalloc(&pdev->dev,
> +                               sizeof(struct clk *) * EXYNOS_AUDSS_MAX_CLKS,
>                                 GFP_KERNEL);
> -       if (!clk_table) {
> -               pr_err("%s: could not allocate clk lookup table\n", __func__);
> -               return;
> -       }
> +       if (!clk_table)
> +               return -ENOMEM;
>  
>         clk_data.clks = clk_table;
>         clk_data.clk_num = EXYNOS_AUDSS_MAX_CLKS;
> -       of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
>  
>         clk_table[EXYNOS_MOUT_AUDSS] = clk_register_mux(NULL, "mout_audss",
>                                 mout_audss_p, ARRAY_SIZE(mout_audss_p),
> @@ -123,13 +127,81 @@ static void __init exynos_audss_clk_init(struct device_node *np)
>                                 "div_pcm0", CLK_SET_RATE_PARENT,
>                                 reg_base + ASS_CLK_GATE, 5, 0, &lock);
>  
> +       for (i = 0; i < clk_data.clk_num; i++) {
> +               if (IS_ERR(clk_table[i])) {
> +                       dev_err(&pdev->dev, "failed to register clock %d\n", i);
> +                       ret = PTR_ERR(clk_table[i]);
> +                       goto unregister;
> +               }
> +       }
> +
> +       ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get,
> +                                       &clk_data);
> +       if (ret) {
> +               dev_err(&pdev->dev, "failed to add clock provider\n");
> +               goto unregister;
> +       }
> +
>  #ifdef CONFIG_PM_SLEEP
>         register_syscore_ops(&exynos_audss_clk_syscore_ops);
>  #endif
>  
> -       pr_info("Exynos: Audss: clock setup completed\n");
> +       dev_info(&pdev->dev, "setup completed\n");
> +
> +       return 0;
> +
> +unregister:
> +       for (i = 0; i < clk_data.clk_num; i++) {
> +               if (!IS_ERR(clk_table[i]))
> +                       clk_unregister(clk_table[i]);
> +       }
> +
> +       return ret;
> +}
> +
> +static int exynos_audss_clk_remove(struct platform_device *pdev)
> +{
> +       int i;
> +
> +       of_clk_del_provider(pdev->dev.of_node);
> +
> +       for (i = 0; i < clk_data.clk_num; i++) {
> +               if (!IS_ERR(clk_table[i]))
> +                       clk_unregister(clk_table[i]);
> +       }
> +
> +       return 0;
>  }
> -CLK_OF_DECLARE(exynos4210_audss_clk, "samsung,exynos4210-audss-clock",
> -               exynos_audss_clk_init);
> -CLK_OF_DECLARE(exynos5250_audss_clk, "samsung,exynos5250-audss-clock",
> -               exynos_audss_clk_init);
> +
> +static const struct of_device_id exynos_audss_clk_of_match[] = {
> +       { .compatible = "samsung,exynos4210-audss-clock", },
> +       { .compatible = "samsung,exynos5250-audss-clock", },
> +       {},
> +};
> +
> +static struct platform_driver exynos_audss_clk_driver = {
> +       .driver = {
> +               .name = "exynos-audss-clk",
> +               .owner = THIS_MODULE,
> +               .of_match_table = exynos_audss_clk_of_match,
> +       },
> +       .probe = exynos_audss_clk_probe,
> +       .remove = exynos_audss_clk_remove,
> +};
> +
> +static int __init exynos_audss_clk_init(void)
> +{
> +       return platform_driver_register(&exynos_audss_clk_driver);
> +}
> +core_initcall(exynos_audss_clk_init);
> +
> +static void __exit exynos_audss_clk_exit(void)
> +{
> +       platform_driver_unregister(&exynos_audss_clk_driver);
> +}
> +module_exit(exynos_audss_clk_exit);
> +
> +MODULE_AUTHOR("Padmavathi Venna <padma.v@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Exynos Audio Subsystem Clock Controller");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:exynos-audss-clk");
> -- 
> 1.8.4
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