Re: [PATCH v2 2/6] clk: mvebu: Add the xtal clock for Armada 3700 SoC

[Michael Turquette]

Quoting Gregory CLEMENT (2016-07-07 15:37:47)
> This clock is the parent of all the Armada 3700 clocks. It is a fixed
> rate clock which depends on the gpio configuration read when resetting
> the SoC.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> ---
>  drivers/clk/mvebu/Kconfig            |  3 ++
>  drivers/clk/mvebu/Makefile           |  1 +
>  drivers/clk/mvebu/armada-37xx-xtal.c | 98 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 102 insertions(+)
>  create mode 100644 drivers/clk/mvebu/armada-37xx-xtal.c
> 
> diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig
> index 3165da77d525..fddc8ac5faff 100644
> --- a/drivers/clk/mvebu/Kconfig
> +++ b/drivers/clk/mvebu/Kconfig
> @@ -24,6 +24,9 @@ config ARMADA_39X_CLK
>         bool
>         select MVEBU_CLK_COMMON
>  
> +config ARMADA_37XX_CLK
> +       bool
> +
>  config ARMADA_XP_CLK
>         bool
>         select MVEBU_CLK_COMMON
> diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
> index 7172ef65693d..4257a36d0219 100644
> --- a/drivers/clk/mvebu/Makefile
> +++ b/drivers/clk/mvebu/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_ARMADA_370_CLK)    += armada-370.o
>  obj-$(CONFIG_ARMADA_375_CLK)   += armada-375.o
>  obj-$(CONFIG_ARMADA_38X_CLK)   += armada-38x.o
>  obj-$(CONFIG_ARMADA_39X_CLK)   += armada-39x.o
> +obj-$(CONFIG_ARMADA_37XX_CLK)  += armada-37xx-xtal.o
>  obj-$(CONFIG_ARMADA_XP_CLK)    += armada-xp.o
>  obj-$(CONFIG_ARMADA_AP806_SYSCON) += ap806-system-controller.o
>  obj-$(CONFIG_ARMADA_CP110_SYSCON) += cp110-system-controller.o
> diff --git a/drivers/clk/mvebu/armada-37xx-xtal.c b/drivers/clk/mvebu/armada-37xx-xtal.c
> new file mode 100644
> index 000000000000..f832c219420f
> --- /dev/null
> +++ b/drivers/clk/mvebu/armada-37xx-xtal.c
> @@ -0,0 +1,98 @@
> +/*
> + * Marvell Armada 37xx SoC xtal clocks
> + *
> + * Copyright (C) 2016 Marvell
> + *
> + * Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2.  This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/clk.h>

Is clk.h necessary? Is this driver also a clock consumer?

Regards,
Mike

> +#include <linux/clk-provider.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define NB_GPIO1_LATCH 0xC
> +#define XTAL_MODE          BIT(31)
> +
> +static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
> +{
> +       struct device_node *np = pdev->dev.of_node;
> +       const char *xtal_name = "xtal";
> +       struct device_node *parent;
> +       struct regmap *regmap;
> +       struct clk_hw *xtal_hw;
> +       unsigned int rate;
> +       u32 reg;
> +       int ret;
> +
> +       xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
> +       if (!xtal_hw)
> +               return -ENOMEM;
> +
> +       platform_set_drvdata(pdev, xtal_hw);
> +
> +       parent = np->parent;
> +       if (!parent) {
> +               dev_err(&pdev->dev, "no parent\n");
> +               return -ENODEV;
> +       }
> +
> +       regmap = syscon_node_to_regmap(parent);
> +       if (IS_ERR(regmap)) {
> +               dev_err(&pdev->dev, "cannot get regmap\n");
> +               return PTR_ERR(regmap);
> +       }
> +
> +       ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
> +       if (ret) {
> +               dev_err(&pdev->dev, "cannot read from regmap\n");
> +               return ret;
> +       }
> +
> +       if (reg & XTAL_MODE)
> +               rate = 40000000;
> +       else
> +               rate = 25000000;
> +
> +       of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
> +       xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
> +       if (IS_ERR(xtal_hw))
> +               return PTR_ERR(xtal_hw);
> +       ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
> +
> +       return ret;
> +}
> +
> +static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
> +{
> +       of_clk_del_provider(pdev->dev.of_node);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
> +       { .compatible = "marvell,armada-3700-xtal-clock", },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, armada_3700_xtal_clock_of_match);
> +
> +static struct platform_driver armada_3700_xtal_clock_driver = {
> +       .probe = armada_3700_xtal_clock_probe,
> +       .remove = armada_3700_xtal_clock_remove,
> +       .driver         = {
> +               .name   = "marvell-armada-3700-xtal-clock",
> +               .of_match_table = armada_3700_xtal_clock_of_match,
> +       },
> +};
> +
> +module_platform_driver(armada_3700_xtal_clock_driver);
> +
> +MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@xxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Marvell Armada 37xx SoC xtal clocks driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.5.0
>